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Sample records for novaya zemlya archipelago

  1. Benthic fauna of Blagopoluchiya Bay (Novaya Zemlya Archipelago, Kara Sea)

    NASA Astrophysics Data System (ADS)

    Udalov, A. A.; Vedenin, A. A.; Simakov, M. I.

    2016-09-01

    The benthic fauna was studied in the Blagopoluchiya Bay (Kara Sea, Novaya Zemlya Archipelago) during an expedition of the R/V Professor Shtokman in autumn 2013. The inner basin of the bay, with depths of around 150 m, is separated from the outer slope of Novaya Zemlya by a shoal 30 m in depth. Six macrobenthic communities were described at nine stations (25 bottom grab samples) taken along a transect from the inner part of the bay to the outer part of the slope. The depths, position on the transect axis and sediment types were the major factors influencing the distribution of the communities. The benthic abundance and biomass in the inner and outer parts of the bay did not differ significantly. The diversity of macrobenthic organisms (α-diversity as the number of species in the sample and β-diversity as the rate of increase in species number in the area) was lower in the inner part of the bay. The intertidal zone (littoral) has been described. The littoral fauna was very poor; it comprised only the amphipods Gammarus setosus inhabiting the near-surface area.

  2. Radioecological investigations on the Northern Novaya Zemlya Archipelago

    NASA Astrophysics Data System (ADS)

    Miroshnikov, A. Yu.; Laverov, N. P.; Chernov, R. A.; Kudikov, A. V.; Ysacheva, A. A.; Semenkov, I. N.; Aliev, R. A.; Asadulin, E. E.; Gavrilo, M. V.

    2017-01-01

    Multidisciplinary investigations carried out in the Cape Zhelaniya area and on the Severny ice dome of Severny Island in the Novaya Zemlya Archipelago during cruise 63 of the R/V Akademik Mstislav Keldysh in September 2015 included a study of the environmental radiation level. The landscape‒geochemical and radiation‒glaciological data show that the Severny ice dome serves as a secondary source of radionuclides on the surface of the ice sheet; this source originated from past nuclear weapons testing in the atmosphere over the Severnaya Zemlya test site. Some samples taken from the periglacial zone near the edge of the Severny ice dome yielded specific activity levels of radioactive cesium of 450-650 Bq/kg. The study of ice cores obtained by shallow (up to 5.4 m) drilling of three boreholes revealed no significant activity values. At the same time, glaciological investigations made it possible to obtain the first data on the previously unexamined glacier, which indicate that the radioactively contaminated layer is located at a depth of 15‒20 m at the boundary of the glacier alimentation zone. No similar investigations had been conducted earlier either by Russian or international scientific teams.

  3. Benthic fauna of Tsivolki Bay (Novaya Zemlya Archipelago, Kara Sea)

    NASA Astrophysics Data System (ADS)

    Chava, A. I.; Udalov, A. A.; Vedenin, A. A.; Simakov, M. I.; Shchuka, S. A.; Mokievsky, V. O.

    2017-01-01

    Benthic fauna in Tsivolki Bay (Novaya Zemlya Archipelago, Kara Sea) has been studied during the voyage of the R/V Professor Shtokman in 2013 and 2014. A peculiar feature of the bay is the presence of the Serp i Molot glacier in its inner part, which determines the extremely high content of suspended particles in the water column. The bay is divided into three parts: the inner part (close to the glacier), the middle basin, and the outer slope. These parts are separated from each other by several rises. Benthic communities changed gradually from the inner part of the bay towards the outer slope. Three communities were described from the data of nine grab stations (26 samples). The apex of the bay is occupied by the depleted community dominated by the isopod Saduria sabini and the bivalve Yoldiella lenticula, which can successfully survive the increased mineral sedimentation. In the middle basin, it is replaced by the transitional community with Ennucula tenuis and Portlandia arctica being the main dominants. Finally, the outer slope is inhabited by the community typical for the open parts of the Kara Sea. It is dominated by Astarte crenata, Ophiacantha bidentata, and Ophiopleura borealis. The main reason for macrobenthic distribution in the studied region is the content of mineral particles in the water column and bottom layers.

  4. Seismicityof the Novaya Zemlya archipelago: relocated event catalog from 1974 to 2014

    NASA Astrophysics Data System (ADS)

    Morozov, Alexey N.; Asming, Vladimir E.; Vaganova, Natalya V.; Konechnaya, Yana V.; Mikhaylova, Yana A.; Evtyugina, Zinaida A.

    2017-07-01

    We have relocated seismic events registered in the area of the Novaya Zemlya Archipelago, which are not identified as nuclear explosions but are probably of tectonic nature. For the relocation, we collected all available seismic bulletins and waveform data. The location was performed by applying a modified method of generalized beamforming. Verification of the modified method and selection of the travel time model were performed using data on two Novaya Zemlya nuclear explosions that occurred on 02.11.1974 and 24.10.1990. The modified method and the BARENTS travel time model provide sufficient accuracy for event location in the region. The relocation procedure was applied for 9 seismic events registered in the area of the Novaya Zemlya Archipelago. As a result, the new coordinates of the five events turned out to be significantly different from those that were defined previously.

  5. New paleomagnetic data from late Paleozoic sedimentary rocks of Novaya Zemlya Archipelago: tectonic implications

    NASA Astrophysics Data System (ADS)

    Abashev, Victor V.; Metelkin, Dmitry V.; Mikhaltsov, Nikolay E.; Vernikovsky, Valery A.; Matushkin, Nikolay Yu.

    2017-04-01

    New paleomagnetic data for Novaya Zemlya archipelago were obtained by processing the samples collection gathered during the 2014 field season. The paleomagnetic directions and paleomagnetic poles were determined from the Paleozoic sedimentary complexes located on the Southern Island (Upper Permian) and the Northern Island (Lower and Upper Devonian, Upper Carboniferous) of the archipelago. Positive fold and reversal tests indicate that the isolated paleomagnetic directions correspond to the primary magnetization components. The corresponding paleomagnetic pole are in good agreement with poles obtained earlier in the 1980s by E.L. Gurevich and I.A. Pogarskaya. Considering the confidence ovals, the paleomagnetic poles obtained for the sites of the Northern Island are located close to the corresponding path segment of the APWP of Europe. This means that at least since the early Devonian, the northern part of Novaya Zemlya Archipelago had a position that was close to its current position relatively to the Arctic margin of Europe and has not undergone significant shifts or rotations. However, the upper Permian paleomagnetic pole for the Southern Island is very different from the corresponding part of the European APWP. We are considering this pole position within a model, involving significant intraplate movement between the structures of the European and Siberian tectonic provinces until the Late Cretaceous. The sinistral strike-slips inferred by the model could have caused or were accompanying the opening of the Mesozoic rift system in Western Siberia. This event has reached its maximum within the South Kara basin and resulted in the north-westward (in geographic coordinates) displacement of the southern part of the Novaya Zemlya Archipelago in relation to the Arctic margin of Europe and in the deformation of the Pay-Khoy-Novaya Zemlya margin, which caused its modern curved form. The study was supported by the Russian Science Foundation, grant No. 14-37-00030 and the

  6. Paleomagnetism of the Upper Carboniferous and Upper Permian sedimentary rocks from Novaya Zemlya Archipelago

    NASA Astrophysics Data System (ADS)

    Abashev, Victor V.; Mikhaltsov, Nikolay E.; Vernikovsky, Valery A.; Metelkin, Dmitry V.; Matushkin, Nikolay Yu.; Doubrovine, Pavel V.

    2016-04-01

    Here we present the first paleomagnetic directions and paleomagnetic poles for Upper Permian and Upper Carboniferous sedimentary rocks (sandstones and limestones) of the Novaya Zemlya Archipelago in the Russian High Arctic region. The paleomagnetic directions were obtained through detailed thermal and alternating field demagnetization experiments, using the principal component analysis of demagnetization data. A positive fold test and a positive reversal test indicate that the isolated paleomagnetic directions correspond to the primary magnetization components. Magnetic remanence carriers were characterized through rock-magnetic analyses, including measurements of temperature dependence of low-field magnetic susceptibility, magnetic hysteresis curves, and first-order reversal curves (FORC). We will describe the rock-magnetic properties of different lithological units and discuss their implications for the stability of natural remanent magnetization (NRM) and the veracity of paleomagnetic record. The tectonics implications of the new paleomagnetic data for the evolution of the Barents-Kara continental margin and the Novaya Zemlya Archipelago will be also discussed. The paleomagnetic poles differ slightly from the corresponding section of the APWP for Baltica, which is probably due to inclination shallowing effect or the tectonic features of the region. The study was supported by Russian Science Foundation grant 14-37-00030, the SIU project HNPla-2013/10049 (HEAT) and by Ministry of Education and Science of the Russian Federation grant 5.515.2014/K.

  7. Geochemical and radiation conditions in coastal landscapes of the Kara Sea Gulf (Novaya Zemlya Archipelago)

    NASA Astrophysics Data System (ADS)

    Laverov, N. P.; Velichkin, V. I.; Miroshnikov, A. Yu.; Krupskaya, V. V.; Asadulin, En. E.; Semenkov, I. N.; Usacheva, A. A.; Zakusin, S. V.; Terskaya, E. V.

    2016-03-01

    This work considers terrestrial coastal landscapes of Abrosimov and Stepovoi gulfs and Yuzhnii (Southern) Island in the Novaya Zemlya Archipelago in the Kara Sea. These areas are dominated by horizons of slightly acidic leptosols and lithic leptosols of 10 cm thick (Stepovoi Gulf) and those of weak skeleton acidic lithic leptosols of 10-15 cm thick (Abrosimov Gulf) covered by moss-shrub assemblages. Kaolinite is formed in a rhizosphere fine earth layer; illite is formed along the leptosol sequence. The studied coastal landscapes are characterized by low accumulation potential of chemical elements, including radionuclides, at higher contents of them. Elements such as Fe and Ti are dispersed in sols, whereas P, S, Cl, Cu, Pb, and Zn are accumulated in soils in minor amounts. Plants accumulate S, P, Cl, Sr, Zn, and 137Cs in minor amounts as well. Elements such as Ti, Mn, Fe, Cr, V, Co, Ni, Cu, Rb, Zr, Ba, Th, Y, Nb, Pb, and As are attributed to the group of weak biological adsorption. The specific 137Cs activity (Bq kg-1) amounts to 10-150 in plants, 10-300 in moor leptosol horizons, and 1-40 in mull horizons.

  8. Geocryological Structure and Glaciers Novaya Zemlya archipelago in the context of global climate processes

    NASA Astrophysics Data System (ADS)

    Kholmiansky, Mikhail; Anokhin, Vladimir

    2015-04-01

    reaches 480 m. Observations of the authors of the glaciers of Novaya Zemlya (Hammer and Sickle, Rose et al.), Carried out in the monitor mode, the last 15 years show an intensive retreat from the shoreline inland archipelago and sharply higher flow of silt-pelitic material kut bays. Lithological changes the picture of the bottom of the bays, which causes certain biogenic transformation of ecosystems.

  9. Novaya Zemlya effect and sunsets

    NASA Astrophysics Data System (ADS)

    van der Werf, Siebren Y.; Können, Günther P.; Lehn, Waldemar H.

    2003-01-01

    Systematics of the Novaya Zemlya (NZ) effect are discussed in the context of sunsets. We distinguish full mirages, exhibiting oscillatory light paths and their onsets, the subcritical mirages. Ray-tracing examples and sequences of solar images are shown. We discuss two historical observations by Fridtjof Nansen and by Vivian Fuchs, and we report a recent South Pole observation of the NZ effect for the Moon.

  10. Fluorescence of dissolved organic matter as a marker for distribution of desalinated waters in the Kara Sea and bays of Novaya Zemlya archipelago

    NASA Astrophysics Data System (ADS)

    Drozdova, A. N.; Patsaeva, S. V.; Khundzhua, D. A.

    2017-01-01

    The optical properties and distribution of dissolved organic matter in the surface waters of the Kara Sea and bays of Novaya Zemlya archipelago were studied during the 63th cruise of the R/V Akademik Mstislav Keldysh. The fluorescence of dissolved organic matter has been studied over wide excitation (230-550 nm) and emission (240-650 nm) wavelength ranges. Based on the results of fluorescence measurements, we propose a simple technique for estimating the relative content of humic compounds entering the Kara Sea shelf region with Ob and Yenisei river runoff. We have found that the blue shift parameters of the DOM fluorescence are Δ270-310 = 28 ± 2 nm and Δ355-310 = 29 ± 2 nm. The highest contents of humic compounds in surface waters were measured on the transect across the desalinated layer of the Kara Sea, near the continental slope on the transect along the St. Anna Trough, and in the area of Sedova, Oga and Tsivol'ki bays. Traces of labile terrigenous organic matter were found in the region of the Voronin Trough, in the bays of the Severny Island of Novaya Zemlya, as well as in some freshwater reservoirs and ice samples of the archipelago. We established a conservative distribution of dissolved organic matter, whose content in water varied from 1.25 to 8.55 mg/L.

  11. Macrobenthos of the Novaya Zemlya Trough

    NASA Astrophysics Data System (ADS)

    Galkin, S. V.; Savilova, T. A.; Moskalev, L. I.; Kucheruk, N. V.

    2010-12-01

    During the 54th cruise of the R/V Akademik Mstislav Keldysh the macrobenthos of the Novaya Zemlya Trough was studied using a Sigsby trawl along the submeridional transect near 75°30'N latitude at a depth range from 68 to 362 m. In total, 140 species of bottom animals were found. The relative role of the taxons was assessed using three indices: the number, biomass, and energy flow. Similarity indices were used for the comparison of the samples. The new material greatly contributes to the data on the composition of the fauna and the structure of the communities of the studied region. It was revealed that small scyphozoid polyps and sipunculoids play an important role in the trough's community. The presence of the community dominated by Ophiocten sericeum (with the important role of small bivalves) was revealed for the first time not only at the eastern by also at the western slope of the Novaya Zemlya Trough. The sharpest changes in the composition and structure of the bottom community were confined to the zone of the transition from the trough floor to the slope. These changes are determined by the specificity of the macrorelief (of the floor and slope), the composition of the ground (soft brown silts abound in rhizopods and dense gray silts with an admixture of pebbles), and possibly by the hydrodynamic processes near the bottom.

  12. Phytoplankton bloom along the coast of Novaya Zemlya, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    North of the western Russian mainland lies the island archipelago of Novaya Zemlya. The northern island is glacier covered and is the site of ongoing research into the effects of the North Atlantic Oscillation and climate change on the glaciers. The archipelago is situated in the Arctic Ocean, between the Barents Sea to the west and the Kara Sea to the east. In this true-color MODIS image, the blue-green swirls in the waters of the Barents Sea on the western coast could indicate a bloom of phytoplankton, or they could be highly reflective glacial silt resulting from run off. The Barents Sea is named for Dutch explorer Willem Barents, who is 1596 attempted to sail to Asia via the North Pole. Barents and his crew were caught in sea ice at north of the northern cape of Novaya Zemlya in August and were forced to winter on the island, building a house out of the wood from their ship. Not just a historic and climatological research site, the islands are also home to a Russian nuclear test facility.

  13. Phytoplankton bloom along the coast of Novaya Zemlya, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    North of the western Russian mainland lies the island archipelago of Novaya Zemlya. The northern island is glacier covered and is the site of ongoing research into the effects of the North Atlantic Oscillation and climate change on the glaciers. The archipelago is situated in the Arctic Ocean, between the Barents Sea to the west and the Kara Sea to the east. In this true-color MODIS image, the blue-green swirls in the waters of the Barents Sea on the western coast could indicate a bloom of phytoplankton, or they could be highly reflective glacial silt resulting from run off. The Barents Sea is named for Dutch explorer Willem Barents, who is 1596 attempted to sail to Asia via the North Pole. Barents and his crew were caught in sea ice at north of the northern cape of Novaya Zemlya in August and were forced to winter on the island, building a house out of the wood from their ship. Not just a historic and climatological research site, the islands are also home to a Russian nuclear test facility.

  14. Novaya Zemlya effect: analysis of an observation.

    PubMed

    Lehn, W H; German, B A

    1981-06-15

    The Novaya Zemlya effect, historically identified with the premature rebirth of the sun during the polar night, is a long range optical ducting phenomenon in the lower atmosphere. An occurrence of the effect was observed at Tuktoyaktuk, Canada (69 degrees 26'N, 133 degrees 02'W) on 16 May 1979, when the minimum solar altitude was - 1 degrees 34'. The sun's image remained above the horizon, within a gray horizontal band, and assumed the various expected shapes, ranging from a bright rectangle filling the band, to three flat suns stacked one over the other, to several thin vertically separated strips. A model for the corresponding atmospheric conditions was identified by matching the observations with images calculated from a computer simulation study.

  15. Novaya Zemlya bora and polar cyclones in spaceborne SAR and optical imagery

    NASA Astrophysics Data System (ADS)

    Ivanov, A. Yu.

    2016-12-01

    Mesoscale meteorological phenomena, such as Novaya Zemlya bora and polar cyclones, have been studied based on the respective signatures in synthetic aperture radar (SAR) images of the sea surface using remote sensing methods. The local bora covers both coastal and open-sea zones of the Barents Sea to the west of Novaya Zemlya and can lead to catastrophic consequences in coastal waters of the archipelago. Another interesting and hardly predictable phenomenon is polar cyclones. The development of especially intensive and catastrophic polar cyclones can be traced using multisensor and multispectral imagery. It has been shown that the application of spaceborne SARs and optical sensors enables real time detection, forecast, and monitoring of Novaya Zemlya bora and polar cyclones in the Barents Sea, giving ground for their detail research.

  16. Recent glacier surface snowpack melt in Novaya Zemlya and Severnaya Zemlya derived from active and passive microwave remote sensing data

    NASA Astrophysics Data System (ADS)

    Zhao, Meng

    The warming rate in the Russian High Arctic (RHA) (36˜158°E, 73˜82°N) is outpacing the pan-Arctic average, and its effect on the small glaciers across this region needs further examination. The temporal variation and spatial distribution of surface melt onset date (MOD) and total melt days (TMD) throughout the Novaya Zemlya (NovZ) and Severnaya Zemlya (SevZ) archipelagoes serve as good indicators of ice mass ablation and glacier response to regional climate change in the RHA. However, due to the harsh environment, long-term glaciological observations are limited, necessitating the application of remotely sensed data to study the surface melt dynamics. The high sensitivity to liquid water and the ability to work without solar illumination and penetrate non-precipitating clouds make microwave remote sensing an ideal tool to detect melt in this region. This work extracts resolution-enhanced passive and active microwave data from different periods and retrieves a decadal melt record for NovZ and SevZ. The high correlation among passive and active data sets instills confidence in the results. The mean MOD is June 20th on SevZ and June 10th on NovZ during the period of 1992-2012. The average TMDs are 47 and 67 days on SevZ and NovZ from 1995 to 2011, respectively. NovZ had large interannual variability in the MOD, but its TMD generally increased. SevZ MOD is found to be positively correlated to local June reanalysis air temperature at 850hPa geopotential height and occurs significantly earlier (˜0.73 days/year, p-value < 0.01) from 1992 to 2011. SevZ also experienced a longer TMD trend (˜0.75 days/year, p-value < 0.05) from 1995 to 2011. Annual mean TMD on both islands are positively correlated with regional summer mean reanalysis air temperature and negatively correlated to local sea ice extent. These strong correlations might suggest that the Russian High Arctic glaciers are vulnerable to the continuously diminishing sea ice extent, the associated air temperature

  17. A dendrochronological analysis of driftwood in the Northern Dvina delta and on northern Novaya Zemlya

    NASA Astrophysics Data System (ADS)

    Johansen, Stein

    2001-09-01

    Analysis of the wood anatomy of modern driftwood logs deposited by the Northern Dvina River, Russia, reveals nearly identical amounts of Picea and Pinus in contrast to the driftwood deposits in the European Arctic, which are dominated by Pinus. Two Picea and two Pinus driftwood chronologies that were constructed could be cross-dated with several chronologies available from the drainage area of the Northern Dvina as well as with driftwood chronologies from Jan Mayen in the Greenland Sea or the Barents Sea coast of north Norway. The degree of cross dating indicates that two major source areas are represented among the driftwood logs examined, i.e., the lower part of the Pinega drainage basin and the eastern central part of the province of Archangel. The origin suggested corresponds with the development of the important logging areas. Driftwood pine and spruce logs from northern Novaya Zemlya cross-dated with chronologies from northwest Russia and the Lower Angara region reveal a transport of ice-rafted wood between the Barents Sea and the northern Kara Sea. Two dispersal routes of driftwood from northwest Russia to locations in the Barents Sea and the Norwegian and Greenland Sea are proposed, via a counter-clockwise circulation in the Barents Sea and via export of drift ice to the Arctic Ocean north of Novaya Zemlya.

  18. The 16 August 1997 Novaya Zemlya seismic event as viewed from GSN stations KEV and KBS

    SciTech Connect

    Hartse, H.E.

    1997-11-01

    Using current and historic seismic records from Global Seismic Network stations KEV and KBS, the authors find that S minus P arrival time comparisons between nuclear explosions and the 16 August 1997 seismic event (m{sub b} {approx} 3.6) from near Novaya Zemlya clearly indicate that (relative to KEV) the 16 August event occurred at least 80 km east of the Russian test site. Including S minus P arrival times from KBS constrains the location to beneath the Kara Sea and in good agreement with previously reported locations, over 100 km southeast of the test site. From an analysis of P{sub n}/S{sub n} waveform ratios at frequencies above 4 Hz, they find that the 16 August event falls within the population of regional earthquakes and is distinctly separated from Novaya Zemlya and other northern Eurasian nuclear explosion populations. Thus, given its location and waveform characteristics, they conclude the 16 August event was an earthquake. The 16 August event was not detected at teleseismic distances, and thus, this event provides a good example of the regional detection, location, and identification efforts that will be required to monitor the Comprehensive Test Ban Treaty below m{sub b} {approx} 4.

  19. The Novaya Zemlya Bora over the Eastern Barents Sea Studied from Space Using Sentinel-1 SAR Images

    NASA Astrophysics Data System (ADS)

    Ivanov, Andrei; Terleeva, Nadezda

    2016-08-01

    By methods of remote sensing, the mesoscale meteorological phenomenon, known as Novaya Zemlya bora, downslope windstorms, which leaves pronounced footprints on the synthetic aperture radar (SAR) images of the sea surface, is investigated. In the winter seasons the Kara Sea is typically ice covered, while the Barents Sea has very low ice concentrations. Weather data indicate that during December - February the windiest conditions occur with monthly mean wind speeds of 10- 15 m/s mainly having southeasterly direction. Although a number of authors have referred to these high speed winds as a bora, there has been no systematic study of this phenomenon. Regular images from Sentinel-1A allow taking a look on this phenomenon from space and restoring extent, strength and duration of the Novaya Zemlya bora.

  20. Sedimentation and mixing rates of radionuclides in Barents Sea sediments off Novaya Zemlya

    NASA Astrophysics Data System (ADS)

    Smith, J. N.; Ellis, K. M.; Naes, K.; Dahle, S.; Matishov, D.

    Radionuclide measurements have been conducted on sediment cores collected in 1992 in the south-eastern region of the Barents Sea, known as the Pechora Sea. Cesium-137 and 239,24OPu activities in surface sediments are generally less than 30 Bq/kg, with the highest levels being measured in sediments off the southwestern coastline of the island of Novaya Zemlya. High correlations between both 137Cs and 239,24OPu and the concentration of fine (< 63 μm) particles in surface sediments indicate that much of the variance in radionuclide concentrations throughout the Pechora Sea can be explained by particle size fractionation. However, elevated activities of 137Cs (138 Bq/kg), 60Co (92 Bq/kg), 241Am (433 Bq/kg), and especially 239,24OPu (8.47 × 103 Bq/kg) were measured in one surface sediment sample from the fjord of Chernaya Bay on the southern coast of Novaya Zemlya. The source of radioactive contamination is two underwater nuclear tests conducted in Chernaya Bay in 1955 and 1957. The 238Pu /239,240Vu activity ratio of 0.0245 in Chernaya Bay is equivalent to values measured in global fallout. The 240Pu /239Pu atom ratio (0.0304), measured by mass spectrometry, is much lower than values (0.18) typical of global fallout, but is consistent with ratios measured for fallout from the early (1951-1955) series of weapons tests at the Nevada Test Site. The timing of the Chernaya Bay source term, estimated from the 241Am /241Pu ratio, is consistent with the timing of the 1955 and 1957 underwater nuclear tests. Relatively low initial yields of 241Pu ( 241Pu /239Pu atom ratio = 0.00 123) in these tests have resulted in relatively low 241Am /239,240Pu activity ratios (0.05) in recent sediments in Chernaya Bay. Radionuclide tracer profiles in cores from the Pechora Sea can be simulated using a two-layer biodiffusion model with rapid, near-homogeneous mixing in the surface mixed layer and reduced mixing in the deep layer. Lead-210 profiles are consistent with a wide range of

  1. Neoproterozoic Mafic Magmatism in Central Novaya Zemlya, Additional Evidence From Zircon and Titanite U-Pb Ages

    NASA Astrophysics Data System (ADS)

    Corfu, F.; Svensen, H.; Planke, S.; Nakrem, H.

    2007-12-01

    Novaya Zemlya is a banana-shaped set of islands stretching northward from the Polar Urals and separating the Barents and Kara Seas. The southernmost part of the islands is an integral component of the Timanides, a Neoproterozoic orogenic belt, which broadly follows the Urals along the eastern and northeastern margin of Baltica. The Timanian event at ca. 600-550 Ma created a folded and imbricated Late-Neoproterozoic basement, which was subsequently unconformably covered by a succession of Early Ordovician to Permian sediments. In more northerly parts of Novaya Zemlya the evidence for such an Early Paleozoic unconformity seems to dissipate, the geological picture being dominated by an apparently continuous sedimentary succession spanning most of the Paleozoic. There is, however, local evidence for the presence of a Precambrian basement comprising Late Neoproterozoic magmatic rocks and perhaps also Mesoproterozoic basement (Korago et al. 2004). In our study we have now obtained further evidence for Neoproterozoic plutonic activity in the region. Zircons were analyzed by ID-TIMS in four gabbroic and dioritic dikes from Matotchkin Strait and Mashigin Fjord in central parts of Novaya Zemlya. They yield U-Pb ages ranging from 716 to 704 Ma, which based on the uniform and characteristic morphology of the zircon populations and the similar titanite age from one sample can be interpreted as dating intrusion of the mafic magmas. These ages indicate a period of magmatism that predated Timanian convergence and collision, perhaps supporting the inference that central parts of Novaya Zemlya were not affected by the Timanian orogeny. The timing of these plutonic events at 716-704 Ma corresponds instead to that of arc magmatism on parts of the Siberian margin (e.g. Vernikovsky et al. 2003) pointing to a possible paleogeographic affiliation of these domains. References Korago, E.A., Kovaleva, G.N., Lopation, B.G. & Orgo,V.V. 2004. The Precambrian rocks of Novaya Zemlya. In Gee, D

  2. Exceptional retreat of Novaya Zemlya's marine-terminating outlet glaciers between 2000 and 2013

    NASA Astrophysics Data System (ADS)

    Carr, J. Rachel; Bell, Heather; Killick, Rebecca; Holt, Tom

    2017-09-01

    Novaya Zemlya (NVZ) has experienced rapid ice loss and accelerated marine-terminating glacier retreat during the past 2 decades. However, it is unknown whether this retreat is exceptional longer term and/or whether it has persisted since 2010. Investigating this is vital, as dynamic thinning may contribute substantially to ice loss from NVZ, but is not currently included in sea level rise predictions. Here, we use remotely sensed data to assess controls on NVZ glacier retreat between 1973/76 and 2015. Glaciers that terminate into lakes or the ocean receded 3.5 times faster than those that terminate on land. Between 2000 and 2013, retreat rates were significantly higher on marine-terminating outlet glaciers than during the previous 27 years, and we observe widespread slowdown in retreat, and even advance, between 2013 and 2015. There were some common patterns in the timing of glacier retreat, but the magnitude varied between individual glaciers. Rapid retreat between 2000 and 2013 corresponds to a period of significantly warmer air temperatures and reduced sea ice concentrations, and to changes in the North Atlantic Oscillation (NAO) and Atlantic Multidecadal Oscillation (AMO). We need to assess the impact of this accelerated retreat on dynamic ice losses from NVZ to accurately quantify its future sea level rise contribution.

  3. Multi-decadal retreat of Novaya Zemlya outlet glaciers, in response to climatic forcing

    NASA Astrophysics Data System (ADS)

    Carr, Rachel; Bell, Heather

    2016-04-01

    Arctic ice masses have rapidly lost ice from the mid-1990s, through a combination of negative surface mass balance and accelerated ice discharge from marine-terminating outlet glaciers. In the past decade, substantial mass deficits have been identified on Novaya Zemlya (NVZ), Russian High Arctic, and its outlet glaciers have retreated dramatically, likely due to declining sea ice concentrations. However, little is known about longer-term glacier behaviour on NVZ, and its potential impact on overall mass balance. Here we greatly extend the available record of retreat and assess multi-decadal glacier response to forcing between 1976 and 2014 using remotely sensed data. Following at least 25 years of gradual recession, retreat rates accelerated substantially from circa. 2000 and again from 2011 onwards. The rate and temporal pattern of retreat were strongly dependant on terminus type: marine-terminating outlets receded an order of magnitude faster than land- or lagoon-terminating glaciers and land-based termini showed limited change in retreat rate over time. Furthermore, retreat was markedly higher on the Barents Sea coast than the Kara Sea. Comparison with forcing data shows that accelerated retreat from 2011 onwards coincided with exceptionally low sea ice concentration and duration between 2011 and 2013. This suggests that sea ice is an important controlling factor, which agrees with shorter-term studies on NVZ. Although air temperature information is more limited on NVZ, data from both meteorological stations and reanalysis highlight 2011 and 2012 as two of the warmest years during the period 1950 to 2014. The limited response of land-terminating outlets suggests that air temperatures do not cause retreat directly, via melting or enhanced basal lubrication, but may have an indirect influence through melting of sea ice or hydro fracture.

  4. Comparative Analysis of Aster Imagery Application To The Glacier Dynamics of Caucasus and Novaya Zemlya

    NASA Astrophysics Data System (ADS)

    Glazovsky, A.; Nosenko, G.; Rototaeva, O.

    State of glaciers on the territory of Russia was documented in the Glacier Inventory of the USSR compiled in 1970s that based on topographic maps and air photo surveys of 1950-1960s. The Inventory covers 20 glaciated areas and is available in paper form and on the NSIDC website. The Inventory contains short text description and basic statistical data about the glaciers >0.1 sq.km (number, name, type, aspect, length, area, highest and lowest altitude, in some cases firn line and ablation area). Geographical coordinates are only in digital version. Paper copy contains very simplified sketches of glacier shapes. This information reflects the state of knowledge about the glaciers for the above-mentioned period and provides a useful reference historical record for comparison with new remote sensing data, but requires additional sources such as maps and other imagery as a base layer. Comparison of ASTER images for northern part of Novaya Zemlya with Inventory data and maps 1:200 000 (based on air photo survey of 1952) shows the dramatic retreat of tidewater glacier fronts that exceeds in some cases 5 km. High quality of ASTER images allows to identify the morphology of active calving fronts, crevassed areas and icebergs size. Comparison of ASTER images for Northern Caucasus (Elbrus area) with Inventory data, maps of 1:200 000 scale (based on air photo survey of 1957) and Russian satellite images shows the general recession of glaciers which confirmed by direct field observations. Our preliminary results suggest that ASTER data might serve as an important source for the Glacier Inventory updating and monitoring of glacier state. Further improvement of ASTER data application requires to solve the problem of accurate image georeferencing.

  5. Step-change in retreat rates on Novaya Zemlya outlet glaciers

    NASA Astrophysics Data System (ADS)

    Carr, Rachel; Bell, Heather; Killick, Rebecca; Holt, Tom

    2017-04-01

    Arctic ice masses have rapidly lost ice from the mid-1990s, through a combination of negative surface mass balance and accelerated ice discharge from marine-terminating outlet glaciers. In the past decade, substantial mass deficits have been identified on Novaya Zemlya (NVZ), Russian High Arctic, and its outlet glaciers began to retreat rapidly, from 2000 onwards. However, little is known about longer-term glacier behaviour on NVZ, meaning we have limited context for their recent acceleration in retreat. Here, we greatly extend the available record of glacier retreat, and assess multi-decadal glacier response to forcing between 1976 and 2015, using remotely sensed data. Using statistical changepoint analysis, we demonstrate a significant change in retreat rates for many glaciers, during the early 2000s. We also show that retreat slowed on numerous outlets from 2013 onwards, and that some glaciers even began to advance. NVZ glaciers have previously shown step-like changes in retreat rates, so we cannot determine whether this represents a longer-term trend or short-term slow-down, but it warrants future monitoring. We also assessed spatial patterns of retreat and found no significant differences in retreat rates according to coast or ice mass. Instead, the rate and temporal pattern of retreat were strongly dependant on terminus type: outlets terminating in lakes or the ocean retreated significantly faster than those ending on land. Interestingly, retreat rates on marine- and lake-terminating glaciers were not significantly different. However, the lake-terminating glaciers showed very little variation in retreat rates between glacier or over time, whereas the variability was very large on ocean-terminating glaciers. In terms of climatic controls, significant changes in Jul-Sep sea ice on both coasts of NVZ coincide with the onset of more rapid retreat, but there is large internnual variability in the data.

  6. Elemental composition of zooplankton in the Kara Sea and the bays on the eastern side of Novaya Zemlya

    NASA Astrophysics Data System (ADS)

    Lobus, N. V.

    2016-11-01

    The chemical composition of zooplankton in the Kara Sea Basin has been studied. Independent samplings of the open sea and the Blagopoluchie and Tsivol'ki bays of Novaya Zemlya testify to the similarity of the distribution pattern of all the studied elements. The chemical composition of samples is predominated by organic carbon (49.5 ± 4.8% of dry weight). The other most important constituent elements are Na, P, S, K, Mg, and Ca. Their average total concentrations are 4.82 ± 0.1%. From an analysis of the composition of major and trace elements of zooplankton in the Kara Sea and the bays of Novaya Zemlya, three groups of elements have been specified: with similar (Corg, K, S, P, Al, Ti, Sc, Cd, Se, Cs, and Rb), lower (Na, Ca, Mg, Fe, Mn, Zn, Sr, Ba, B, Cu, Pb, Cr, Ni, V, Co, Sb, Mo, Ag, Be, Ga, and Hg), and higher (Li, As, and U) contents compared to their mean concentrations in ocean zooplankton.

  7. 239,240Pu transport into the Arctic Ocean from underwater nuclear tests in Chernaya Bay, Novaya Zemlya

    NASA Astrophysics Data System (ADS)

    Smith, J. N.; Ellis, K. M.; Polyak, L.; Ivanov, G.; Forman, S. L.; Moran, S. B.

    2000-03-01

    Radionuclide measurements have been conducted on sediment, seawater and biota samples collected in Chernaya Bay, on the southern coast of Novaya Zemlya, the site of two underwater nuclear tests conducted in the 1950s. 239,240Pu levels in sediments from the central region of Chernaya Bay exceed concentrations of 15,000 Bq/kg, and are among the highest ever reported for the marine environment. It is estimated that approximately 11 TBq of 239,240Pu from the tests has been retained in the sediments of Chernaya Bay. Plutonium from Chernaya Bay is distinguished by 240Pu/ 239Pu atom ratios of 0.03 that are much lower than ratios of 0.18 typical of global fallout. High levels of 137Cs (Bq/kg) and 60Co (Bq/kg) were also measured in surface sediments in the central regions of Chernaya Bay near the presumed epicentre of the explosions. Applications of a biodiffusion model to excess 210Pb sediment depth profiles indicate that the distribution of 239,240Pu is governed mainly by sediment mixing in this low sedimentation rate (<0.1 cm/yr) regime and, as a result, most of the 239,240Pu has been retained in the upper 20 cm of the sediment column. Elevated levels of 239,240Pu measured in Macoma (104 Bq/kg), Fucus (15 Bq/kg) and polychaete (1292 Bq/kg) from Chernaya Bay, indicate that 239,240Pu levels in the benthos are comparatively high and that significant uptake has occurred in the food chain. Although levels of 239,240Pu in bottom water from Chernaya Bay are high (4.2 Bq/m 3), restricted exchange over the fjord sill limits the present rates of 239,240Pu transport from contaminated sites in Chernaya Bay into the eastern Barents Sea. However, low 240Pu/ 239Pu atom ratios measured in sediment cores collected throughout the eastern Barents Sea indicate that significant offshore transport of plutonium from Chernaya Bay has occurred in the past, probably at the time of the original nuclear tests. The large difference in end member 240Pu/ 239Pu atom ratios for Chernaya Bay fallout (0

  8. Radioecological investigations in shallow bays of the Novaya Zemlya Archipelago in 2002-2005.

    PubMed

    Stepanets, O; Borisov, A; Ligaev, A; Solovjeva, G; Travkina, A

    2007-01-01

    The results of a survey of underwater disposal sites of potentially hazardous objects in the Kara Sea and Oga, Tsivolky, Stepovoy and Abrosimov Bays are presented. Radionuclide levels were determined, using gamma-spectrometric and radiochemical methods, in zones near to and remote from buried solid radioactive waste in the outer and inner parts of the Bays. At the repository of the solid radioactive waste containers in the inner part of the Stepovoy Bay and Abrosimov Bay, higher than background concentrations of (137)Cs were determined in samples of bottom sediments. At one of the sites located in the Stepovoy Bay (137)Cs and (60)Co were detected.

  9. Geology of the Severnaya Zemlya Archipelago and the North Kara Terrane in the Russian high Arctic

    NASA Astrophysics Data System (ADS)

    Lorenz, Henning; Männik, Peep; Gee, David; Proskurnin, Vasilij

    2008-05-01

    The Severnaya Zemlya Archipelago is located at 80°N near the continental shelf break, between the Kara and Laptev seas. Sedimentary successions of Neoproterozoic and Palaeozoic age dominate the bedrock geology. Together with Northern Tajmyr, Severnaya Zemlya constitutes the main land areas of the North Kara Terrane (NKT), which is inferred here to have been a part of the Timanide margin of Baltica, i.e. an integral part of Baltica at least since the Vendian. Vendian turbidites derived from the Timanide Orogen are inferred to have been deposited on Neoproterozoic greenschist facies, granite-intruded basement. Shallow-water siliclastic deposition in the Early to Mid-Cambrian was followed by highly organic-rich shales in the Late Cambrian and influx of more turbidites. An episode of folding, the Kan’on River deformation, separates these formations from the overlying Tremadocian conglomerates and sandstones. In the Early Ordovician, rift-related magmatic rocks accompanied the deposition of variegated marls, sandstones, carbonates and evaporites. Dark shales and gypsiferous limestones characterise the Mid-Ordovician. Late Ordovician quartz-sandstones mark a hiatus, followed by carbonate rocks that extend up into and through most of the Silurian. The latter give way upwards into Old Red Sandstones, which are inferred to have been deposited in a Caledonian foreland basin. Deformation, reaching the area in the latest Devonian or earliest Carboniferous and referred to as the Severnaya Zemlya episode, is thought to be Caledonian-related. The dominating E-vergent structure was controlled by décollement zones in Ordovician evaporite-bearing strata; detachment folds and thrusts developed in the west and were apparently impeded by a barrier of Ordovician igneous rocks in the east. Below the décollement zones, the Neoproterozoic to Early Ordovician succession was deformed into open to close folds. The exposed strata in the lower structural level have been juxtaposed with

  10. Surface Elevation Changes and Velocities from Remote-Sensing Data at Vil'kitskogo, Inostranzeva and Bunge Glaciers on the Novaya Zemlya Icefield in the Russian High Arctic

    NASA Astrophysics Data System (ADS)

    Melkonian, A. K.; Willis, M. J.; Pritchard, M. E.; Stewart, A.

    2013-12-01

    The Northern Ice Cap of Novaya Zemlya is the largest (22,000 km2) and most rapidly changing ice cap in the Russian High Arctic, accounting for 80% of the region's estimated 0.025 mm/yr contribution to sea level rise between 2003-2009 (Moholdt et al., 2012). We use several remote sensing instruments to extend this time series forward and instead of computing a regional average, we seek a detailed glacier-by-glacier inventory of elevation and velocity changes. Here, we focus on three glaciers along the Barents Sea coast of the ice cap: Vil'kitskogo, Inostranzeva and Bunge, all of which experienced area reduction at an average rate of roughly 1 sq. km/yr from 1990 to 2000 (Kouraev, Legrésy and Remy, 2006). Our estimates of the current surface elevation change rates (dh/dt) and velocities at these glaciers will allow us to determine the connections between thinning, dynamics and the documented climatic changes -- 2004-2009 mean summer temperatures in Novaya Zemlya were anomalously high, +0.50×0.28C greater than mean summer temperatures from 1980-2009 (Moholdt et al., 2012), while Meng (2013) found that melt duration increased by 1.3 days/yr from 1996 to 2011. Based on warming and increased melt in the region, we expect to find a seasonally-related increase in velocity. Comparing acceleration (or the lack thereof) with thinning rates and combining both with existing bathymetry to calculate flux will enable us to estimate the contribution of dynamics to mass change at these glaciers relative to melt. We estimate dh/dt by applying a weighted linear regression to time series of ASTER DEMs acquired between 2003/07/29 to 2013/07/27 and Russian cartographic DEMs issued in 1970/71. Glacier velocities are calculated using automated normalized cross correlation, or 'pixel-tracking', applied to ASTER image pairs from 2003 to 2013. We supplement our ASTER time series with velocities and DEMs from very high-resolution (0.5-2 m/pixel) imagery acquired by QuickBird, WorldView and

  11. Ice flow velocity, elevation change and discharge variation in Novaya Zemlya using SAR and Landsat offset-tracking and radar altimetry

    NASA Astrophysics Data System (ADS)

    Sun, Z.; Lee, H.; Ahn, Y.; Tseng, K. H.; Erkin, A.

    2015-12-01

    Discharge is one of the most important parameters for describing the dynamic status of glaciers. In recent years, observations from satellite sensors and in-situ stations have been combined to provide this critical data. However, over the regions with little or no in-situ data, such as Novaya Zemlya, satellite remote sensing technique becomes the only option. Without the in-situ ice thickness data, the absolute glacier discharge could not be obtained. An alternative way would be to combine the ice velocity and elevation change to estimate the discharge change. In order to obtain the ice flow velocity, Landsat 7 ETM+ and SAR offset-tracking of eight L-band ALOS PALSAR data are performed for these fast-moving glaciers spanning from 2007 to 2010. Envisat RA-2 radar altimetry data are used to estimate glacier elevation changes from 2002 to 2010 using collinear method (Lee et al., RSE, 2013) over eight different locations. All of the altimetry time series reveal decreasing elevation changes until year 2007, and then increasing elevation changes. This change in trends also agrees with the mass change time series obtained from GRACE. Snow depth and temperature anomalies from ERA-interim are also examined to explain change in mass variation rates. However, since all of the Envisat altimetry stations are located upstream of the glaciers, we attempt to extrapolate Envisat-derived elevation changes along the glacier streams with an aid of ICESat altimetry that passes exactly along the glacier stream. Estimated discharge changes along the glacier stream will be compared with an existing approach using ice thickness derived from ice flow velocity.

  12. Main results of the 2012 joint Norwegian-Russian expedition to the dumping sites of the nuclear submarine K-27 and solid radioactive waste in Stepovogo Fjord, Novaya Zemlya.

    PubMed

    Gwynn, Justin P; Nikitin, Aleksander; Shershakov, Viacheslav; Heldal, Hilde Elise; Lind, Bjørn; Teien, Hans-Christian; Lind, Ole Christian; Sidhu, Rajdeep Singh; Bakke, Gunnar; Kazennov, Alexey; Grishin, Denis; Fedorova, Anastasia; Blinova, Oxana; Sværen, Ingrid; Lee Liebig, Penny; Salbu, Brit; Wendell, Cato Christian; Strålberg, Elisabeth; Valetova, Nailja; Petrenko, Galina; Katrich, Ivan; Logoyda, Igor; Osvath, Iolanda; Levy, Isabelle; Bartocci, Jean; Pham, Mai Khanh; Sam, Adam; Nies, Hartmut; Rudjord, Anne Liv

    2016-01-01

    This paper reports the main results of the 2012 joint Norwegian-Russian expedition to investigate the radioecological situation of the Stepovogo Fjord on the eastern coast of Novaya Zemlya, where the nuclear submarine K-27 and solid radioactive waste was dumped. Based on in situ gamma measurements and the analysis of seawater and sediment samples taken around the submarine, there was no indication of any leakage from the reactor units of K-27. With regard to the radioecological status of Stepovogo Fjord, activity concentrations of all radionuclides in seawater, sediment and biota in 2012 were in general lower than reported from the previous investigations in the 1990s. However in 2012, the activity concentrations of (137)Cs and, to a lesser extent, those of (90)Sr remained elevated in bottom water from the inner part of Stepovogo Fjord compared with surface water and the outer part of Stepovogo Fjord. Deviations from expected (238)Pu/(239,240)Pu activity ratios and (240)Pu/(239)Pu atom ratios in some sediment samples from the inner part of Stepovogo Fjord observed in this study and earlier studies may indicate the possibility of leakages from dumped waste from different nuclear sources. Although the current environmental levels of radionuclides in Stepovogo Fjord are not of immediate cause for concern, further monitoring of the situation is warranted.

  13. Multivariate Seismic Calibration for the Novaya Zemlya Test Site

    DTIC Science & Technology

    1992-09-30

    every multivariate magnitude combination. A classical confidence interval is presented to estimate future yields, based on estimates of the unknown...multivariate calibration parameters. A test of TTBT compliance and a definition of the F-number, based on the confidence interval , are also provided. F

  14. The Taimyr Peninsula and the Severnaya Zemlya archipelago, Arctic Russia: a synthesis of glacial history and palaeo-environmental change during the Last Glacial cycle (MIS 5e-2)

    NASA Astrophysics Data System (ADS)

    Möller, Per; Alexanderson, Helena; Funder, Svend; Hjort, Christian

    2015-01-01

    We here suggest a glacial and climate history of the Taimyr Peninsula and Severnaya Zemlya archipelago in arctic Siberia for the last about 150 000 years (ka). Primarily it is based on results from seven field seasons between 1996 and 2012, to a large extent already published in papers referred to in the text - and on data presented by Russian workers from the 1930s to our days and by German colleagues working there since the 1990s. Although glaciations even up here often started in the local mountains, their culminations in this region invariably seems to have centred on the shallow Kara Sea continental shelf - most likely due to expanding marine ice-shelves grounding there, as a combined effect of thickening ice and eustatically lowered sea-levels. The most extensive glaciation so far identified in this region (named the Taz glaciation) took place during Marine Isotope Stage 6 (MIS 6), i.e. being an equivalent to the late Saale/Illinoian glaciations. It reached c. 400 km southeast of the Kara Sea coast, across and well beyond the Byrranga Mountain range and ended c. 130 ka. It was followed by the MIS 5e (Karginsky/Eemian) interglacial, with an extensive marine transgression to 140 m above present sea level - facilitated by strong isostatic downloading during the preceding glaciation. During the latest (Zyryankan/Weichselian/Wisconsinan) glacial cycle followed a series of major glacial advances. The earliest and most extensive, culminating c. 110-100 ka (MIS 5d-5e), also reached south of the Byrranga mountains and its post-glacial marine limit there was c. 100 m a.s.l. The later glacial phases (around 70-60 ka and 20 ka) terminated at the North Taimyr Ice Marginal Zone (NTZ), along or some distance inland from the present northwest coast of Taimyr. They dammed glacial lakes, which caused the Taimyr River to flow southwards where to-day it flows northwards into the Kara Sea. The c. 20 ka glacial phase, contemporary with the maximum (LGM) glaciation in NW Europe

  15. Mineral composition of soils and bottom sediments in bays of Novaya Zemlya

    NASA Astrophysics Data System (ADS)

    Krupskaya, V. V.; Miroshnikov, A. Yu.; Dorzhieva, O. V.; Zakusin, S. V.; Semenkov, I. N.; Usacheva, A. A.

    2017-01-01

    We have analyzed the specific features of the mineralogical composition of bottom sediments of Blagopoluchiya, Tsivol'ki, and Abrosimov bays and soils on Cape Zhelaniya and the coasts of Abrosimov and Stepovoi bays. The data were obtained during two scientific expeditions of the R/V Professor Shtokman in 2014 (cruise 128) and R/V Akademik Mstislav Keldysh in 2015 (cruise 63). These investigations revealed patterns in the transportation of terrigenous material in the coastal zone of the bays: a decrease in the share of nonclay minerals and an increase in that of clay minerals with distance from shore. The increase in kaolinite and smectite content in soil horizons is related to biochemical weathering, while illite is mainly formed as a result of physical weathering.

  16. The outflow of radionuclides from Novaya Zemlya bays--modeling and monitoring strategies.

    PubMed

    Harms, I H; Povinec, P P

    1999-09-30

    Hydrodynamic model results are used to evaluate possible monitoring strategies for a continuous survey of underwater dump sites. The Hamburg Shelf Ocean Model (HAMSOM) is applied to Abrosimov Bay and forced with realistic, transient wind fields and air temperatures. The three-dimensional circulation model is coupled to a dynamic-thermodynamic ice model that accounts for surface heat fluxes, fractional ice cover and ice thickness. Model results show significant variations in the bay circulation due to a pronounced seasonality in the wind forcing and the ice cover. The circulation is weakest in early summer when wind speeds are low and the ice still covers most parts of the bay. In autumn, circulation and flushing of the bay is most enhanced, due to increasing wind speeds and the absence of an ice cover. Dispersion scenarios were carried out assuming a leakage at dumped objects. During most of the year the obtained tracer concentrations in the bay are higher in the upper layers than close to the bottom, indicating an outflow at the surface and a compensatory inflow below. This general pattern is only reversed during spring and early summer, when the wind directions change. Since ice problems make it almost impossible to monitor surface waters or even the whole water column in a shallow bay, the only way to install a monitoring system, is at the bottom of the bay, as close as possible to dumped objects. Data transmission via satellite or radio could be realized from a small station located on the bay's edge.

  17. Investigation of Historic Seismic and Infrasound Records from Events Occurred at the Region of Novaya Zemplya Test Site by the USSR Stations

    NASA Astrophysics Data System (ADS)

    Sokolova, Inna

    2014-05-01

    Located in the north the Novaya Zemlya Test Site was used in Soviet time for conducting unique nuclear weapon tests in different mediums. 130 nuclear explosions with total yield 265 megatons were conducted at the Test Site for the period 1955-1990. During this period the following nuclear explosions were conducted: 1 surface explosion, 85 air explosions, 2 above water explosions, 3 underwater explosions and 39 underground explosions (in boreholes and tunnels). In addition, tectonic earthquakes and induced earthquakes caused by multi-megatons UNE occur near the Test Site. Unfortunately, only few seismic events occurred on the territory of the Test Site were recorded by digital stations. However, the archives of different seismological organizations of the USSR contain huge amount of analogue seismograms recorded by permanent and temporary stations. Historical seismograms of nuclear explosions and earthquakes from Novaya Zemlya Test site territory were digitized by the Complex Seismological Expedition IPE RAS and by the Institute of Geophysical Researches RK; a database of the events from the Test Site containing 470 seismograms at epicentral distance 2100-3800 was created. The database includes seismic records of air, underground nuclear explosions, and records of underwater nuclear explosion conducted within "Korall" exercise. In addition, infrasound records of waves from multi-megatons air nuclear explosions recorded by a microbarograph installed at Talgar seismic station at distance ~3600 km from the Test Site were digitized. Kinematic and dynamic parameters of nuclear explosions records conducted in different mediums (air, under water and underground) were investigated by the digitized records from events at Novaya Zemlya Test Site; specific features of wave pattern for each class of events were found.

  18. Outlet glacier response to the 2012 collapse of the Matusevich Ice Shelf, Severnaya Zemlya, Russian Arctic

    NASA Astrophysics Data System (ADS)

    Willis, Michael J.; Melkonian, Andrew K.; Pritchard, Matthew E.

    2015-10-01

    The Matusevich Ice Shelf (MIS), located within the Severnaya Zemlya Archipelago in the Russian Arctic, rapidly broke apart between 10 August and 7 September 2012. We examine the response of the outlet glaciers that fed the MIS from local ice caps to the removal of the ice shelf. We use spaceborne laser altimetry and multiple optically derived digital elevation models to track ice surface elevation change rates (dh/dt) between 1984 and 2014. Glacier speeds are measured by pixel-tracking from optical and RADAR imagery between 2010 and 2014 and interferometric synthetic aperture radar in 1995 to compare precollapse and postcollapse velocities. We find that the three main outlet glaciers that fed the MIS are thinning an order of magnitude more rapidly than most of the rest of Severnaya Zemyla, based upon ICESat data from 2003 to 2009. Recent, 2012 to 2014 thinning rates are three to four times faster than the 30 year average thinning rate, calculated between 1984 and 2014. The springtime speeds of the largest outlet glacier (Issledovateley) have increased more than 200% at the terminus between April 2010 and April 2014. To date, changes in surface elevation (dh/dt) and velocity at the outlet glaciers near MIS are smaller than glacier responses to ice shelf collapse in Antarctica. It is possible that the MIS was already very weak prior to the 2012 collapse and unable to support back stress. Further observations are required to assess whether the thinning and nonmelt season glacier speeds are continuing to accelerate.

  19. Mergui Archipelago

    NASA Image and Video Library

    2017-09-27

    NASA image acquired December 14, 2004 In the southernmost reaches of Burma (Myanmar), along the border with Thailand, lies the Mergui Archipelago. The archipelago in the Andaman Sea is made up of more than 800 islands surrounded by extensive coral reefs. This natural color image acquired by Landsat 5 on Dec. 14, 2004, shows the middle portion of the archipelago, including Auckland and Whale Bays. Swirling patterns are visible in the near-shore waters as sediments carried by rivers slowly settle out and are deposited on the seafloor. The heavy sediment loads make the river appear nearly white. As those sediments settle out, the seawater appears deeper shades of blue. The tropical rainforests of the region appear deep green. Captain Thomas Forrest of the East India Company first described the region to Europeans after a 1782 expedition in search of potential sugar-growing lands. At that time, the islands were mainly inhabited by a nomadic fishing culture. These people, known as the Moken, still call the archipelago home and mostly live a hunter-gatherer lifestyle. As of 2006, 2,000 Moken were known to inhabit the Burmese portion of Mergui. The small population of the archipelago has helped preserve its high diversity of plants and animals. In 1997, Burma opened the region to foreign tourism and in the years since it has become a major diving destination. A valued species of pearl oyster (Pinctada maxima) are found in nearby waters. Today, overfishing is emerging as a regional problem. Landsat image created by Michael Taylor, Landsat Project Science Office. Caption by Laura Rocchio. Instrument: Landsat 5 - TM To read more go to: 1.usa.gov/TDmjsk Credit: NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to

  20. Lithology and minerageny of black shale of the Taimyr-Severnaya Zemlya region

    NASA Astrophysics Data System (ADS)

    Mozoleva, Irina

    2014-05-01

    In the Taimyr Peninsula and Severnaya Zemlya Archipelago, black shale deposits are widespread - subaqueous fine-grained, often thin-bedded, dark-coloured rocks of clayey, carbonate, silica or mixed composition, significantly enriched (1-18%) with organic matter (OM). Two large age intervals of accumulation are distinguished: Riphean and Early-Middle Paleozoic (with maxima in the Ordovician and Silurian). Black shale Riphean complexes are spread in the northern part of the Taimyr Peninsula, where they build up a strip 100-150 km wide along the coast from the Gulf of Minin to the Gulf of Thaddeus and on Bolshevik Isl. Two types of black shale deposits are distinguished (Zabiyaka, 1972; Kabankov, 1980). The first type - predominantly siliciclastic deposits. Represented by cyclical alternation of flyschoid and turbidite types of terrigenous deposits with carbonaceous shale members. Deposits are unevenly enriched in OM in the form of filamentous, lenticular, lumpy accumulations and are often accompanied by pyrite. OM content to 2.5%, rarely to 6%. The second type - carbonate-terrigenous-clayey deposits. Represented by intensely displaced metamorphosed sandstone, siltstone, and mudstone interbedded with marble and limestone. Carbonaceous deposits are intensively. OM content 0.66-2.3%. OM is distributed unevenly, often localized along fractures. Black shale complexes of Middle-Lower Paleozoic age include deposits from the Lower Cambrian to Lower Carboniferous (Sobolevskaya et al., 1979; Lazarenko, 1980). On October Revolution Isl., the Lower Cambrian-Lower Ordovician deposits are spread. In Taimyr, black shale complexes build up a relatively narrow, about 75-100 km, strip stretching in sublatitudinal direction, limited by regional faults (Main Taimyr in the north, Pyasina-Faddey in the south). Deposits are represented by a wide range of lithological genetic rock types. Carbonate-argillaceous rocks with terrigenous material admixture and siliceous-terrigenous with a small

  1. Monitoring Glacier change at the Academy of Sciences Icecap, Severnaya Zemlya, Russian High Arctic

    NASA Astrophysics Data System (ADS)

    Ornelas, G.; Willis, M. J.; Pritchard, M. E.; Melkonian, A. K.

    2014-12-01

    The 2200 km3 Academy of Sciences ice cap, located on Komsomolets Island in the Severnaya Zemlya Archipelago, is the largest ice cap by volume in the Russian High Arctic (Dowdeswell et al., 2002). We use remote sensing observations to examine velocity and elevation changes at its five major outlet glaciers over the past few decades. We obtain glacier velocities by applying pixel-tracking (normalized amplitude cross-correlation) to orthorectified, high-resolution image pairs acquired by WorldView 1 and 2 with an ideal time separation of 1-3 months. We select imagery from the spring and summer periods where crevasses are clearly observed. We estimate uncertainties by examining apparent motion at bedrock outcrops adjacent to the glaciers, and use these off-ice offsets to correct for elevation-dependent errors. We compare our observations of velocities from high-resolution optical imagery between 2011 and 2014 with rates of motions measured in the 1990's and 2000's by Landsat, ASTER and SAR (Moholdt et al., 2012; Stewart, 2014) to determine if the velocities have changed. Ice streams B, C, and D have maximum velocities of 2.8 m/day, 2.5 m/day and 2.3 m/day, respectively. Our velocities are similar to observations from 2009-2012 (Stewart, 2014), and higher than 1995 velocities (Moholdt et al.). We provide constraints on seasonal velocity variations at Ice Streams B, C and D. Ice elevation change rates (determined using Worldview DEMs compared to a cartographically produced DEM) are consistent with those measured over the ICESat era between 2003 and 2009. In general the south and east of the ice cap is thinning, while the north and west is thickening. The main body of the land terminating Icestream A is continuing to slowly thicken, while thinning rates of more than 1-2 m/yr are occurring at the remaining marine terminating ice streams. Thinning extends to the highest altitude of the ice cap and crosses ice stream catchments boundaries.

  2. Aaland Archipelago, Finland

    NASA Image and Video Library

    2011-04-27

    This image, acquired by NASA Terra spacecraft, is of the Aaland archipelago at the mouth of the Gulf of Bothnia which belongs to Finland, though it enjoys autonomy from Helsinki and locals speak Swedish.

  3. Dynamics of radionuclide concentrations in calcified tissues of reindeer in the western Russian Arctic.

    PubMed

    Klevezal, G A; Bakhur, A E; Kalyakin, V N; Krushinskaya, N L

    2001-01-01

    The specific activities of artificial and natural nuclides were determined in bone and teeth of reindeer that had lived before, during, and after nuclear tests on the Archipelago Novaya Zemlya and of reindeer from the nearby mainland region. In bone of reindeer from Novaya Zemlya, 90Sr and 210Pb are the main source of beta-activity, the 210Po is the main source of the alpha activity. In bone of reindeer that lived on Novaya Zemlya during underground tests, the 90Sr activity was relatively high (0.75 +/- 0.20 Bq/g dry weight). In animals that lived after the tests were banned, the level was significantly lower (0.44 +/- 0.17 Bq/g) and did not differ from the level of the 90Sr activity found in the mainland reindeer bone. On Novaya Zemlya, the concentrations of the natural 210Pb in bone of the recent reindeer (0.57 +/- 0.19 Bq/g) is similar to that which was in the teeth of reindeer a hundred years ago (0.65-0.75 Bq/g) and significantly higher than in the recent mainland reindeer from different regions (0.18-0.17 Bq/g).

  4. Hydrochemical features of the Kara Sea aquatic area in summer 2015

    NASA Astrophysics Data System (ADS)

    Makkaveev, P. N.; Polukhin, A. A.; Kostyleva, A. V.; Protsenko, E. A.; Stepanova, S. V.; Yakubov, Sh. Kh.

    2017-01-01

    During cruise 65 of the R/V Akademik Mstislav Keldysh in the Kara Sea, three transects were executed: one eastwards from the Novaya Zemlya Archipelago and two in the St. Anna and Voronin troughs. It was noted that the continental runoff affected the entire surveyed aquatic area, even at the northern extremity of the Novaya Zemlya Archipelago. The transect along the St. Anna Trough showed the presence of a slope frontal zone overlaid at the surface by a desalinated layer. The Voronin Trough was characterized by sliding of slope waters. The hydrochemical parameters show that the surveys were carried out during a recession of biological activity of the waters and that the peak bloom was over by that time. The hydrochemical structure of waters conformed to early autumn conditions, but before the beginning of intense cooling of surface waters.

  5. Canary Island Archipelago

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This nearly vertical view of the Canary Archipelago (28.5N, 16.5W) shows five of the seven islands: Grand Canary, Tenerife, Gomera, Hierro and La Palma. The largest island in view is Tenerife. Island cloud wakes evident in this photo are the result of southerly winds giving rise to cloud banks on the lee side especially on Tenerife which has the highest volcanic peaks. Island water wakes and internal waves are also evident but not as apparent.

  6. Hawaiian Island Archipelago

    NASA Image and Video Library

    1985-06-24

    The entire Hawaiian Island Archipelago (21.5N, 158.0W) is seen in this single view. The islands are a favorite international resort and tourist attraction drawing visitors from all over the world to enjoy the tropical climate, year round beaches and lush island flora. Being volcanic in origin, the islands' offer a rugged landscape and on the big island of Hawaii, there is still an occasional volcanic eruption of lava flows and steam vents.

  7. Hawaiian Island Archipelago

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The entire Hawaiian Island Archipelago (21.5N, 158.0W) is seen in this single view. The islands are a favorite international resort and tourist attraction drawing visitors from all over the world to enjoy the tropical climate, year round beaches and lush island flora. Being volcanic in origin, the islands' offer a rugged landscape and on the big island of Hawaii, there is still an occasional volcanic eruption of lava flows and steam vents.

  8. New geological data of New Siberian Archipelago

    NASA Astrophysics Data System (ADS)

    Sobolev, Nikolay; Petrov, Evgeniy

    2014-05-01

    The area of New Siberian Archipelago (NSA) encompasses different tectonic blocks is a clue for reconstruction of geological structure and geodynamic evolution of East Arctic. According to palaeomagnetic study two parts of the archipelago - Bennett and Anjou Islands formed a single continental block at least from the Early Palaeozoic. Isotope dating of De Long Islands igneous and sedimentary rocks suggests Neoproterozoic (Baikalian) age of its basement. The De Long platform sedimentary cover may be subdivided into two complexes: (1) intermediate of PZ-J variously deformed and metamorphosed rocks and (2) K-KZ of weakly lithified sediments. The former complex comprises the Cambrian riftogenic volcanic-clastic member which overlain by Cambrian-Ordovician turbiditic sequence, deposited on a continental margin. This Lower Palaeozoic complex is unconformably overlain by Early Cretaceous (K-Ar age of c.120 Ma) basalts with HALIP petrochemical affinities. In Anjou Islands the intermediate sedimentary complex encompasses the lower Ordovician -Lower Carboniferous sequence of shallow-marine limestone and subordinate dolomite, mudstone and sandstone that bear fossils characteristic of the Siberian biogeographic province. The upper Mid Carboniferous - Jurassic part is dominated by shallow-marine clastic sediments, mainly clays. The K-KZ complex rests upon the lower one with angular unconformity and consists mainly of coal-bearing clastic sediments with rhyolite lavas and tuffs in the bottom (117-110 Ma by K-Ar) while the complexe's upper part contains intraplate alkalic basalt and Neogene-Quaternary limburgite. The De-Long-Anjou block's features of geology and evolution resemble those of Wrangel Island located some 1000 km eastward. The Laptev Sea shelf outcrops in intrashelf rises (Belkovsky and Stolbovoy Islands) where its geology and structure may be observed directly. On Belkovsky Island non-dislocated Oligocene-Miocene sedimentary cover of littoral-marine coal

  9. Alexander Archipelago, Southeastern Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    West of British Columbia, Canada, and south of the Yukon Territory, the southeastern coastline of Alaska trails off into the islands of the Alexander Archipelago. The area is rugged and contains many long, U-shaped, glaciated valleys, many of which terminate at tidewater. The Alexander Archipelago is home to Glacier Bay National Park. The large bay that has two forks on its northern end is Glacier Bay itself. The eastern fork is Muir inlet, into which runs the Muir glacier, named for the famous Scottish-born naturalist John Muir. Glacier Bay opens up into the Icy Strait. The large, solid white area to the west is Brady Icefield, which terminates at the southern end in Brady's Glacier. To locate more interesting features from Glacier Bay National Park, take a look at the park service map. As recently as two hundred years ago, a massive ice field extended into Icy Strait and filled the Glacier Bay. Since that time, the area has experienced rapid deglaciation, with many large glaciers retreating 40, 60, even 80 km. While temperatures have increased in the region, it is still unclear whether the rapid recession is part of the natural cycle of tidewater glaciers or is an indicator of longer-term climate change. For more on Glacier Bay and climate change, read an online paper by Dr. Dorothy Hall, a MODIS Associate Science Team Member. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  10. Alexander Archipelago, Southeastern Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    West of British Columbia, Canada, and south of the Yukon Territory, the southeastern coastline of Alaska trails off into the islands of the Alexander Archipelago. The area is rugged and contains many long, U-shaped, glaciated valleys, many of which terminate at tidewater. The Alexander Archipelago is home to Glacier Bay National Park. The large bay that has two forks on its northern end is Glacier Bay itself. The eastern fork is Muir inlet, into which runs the Muir glacier, named for the famous Scottish-born naturalist John Muir. Glacier Bay opens up into the Icy Strait. The large, solid white area to the west is Brady Icefield, which terminates at the southern end in Brady's Glacier. To locate more interesting features from Glacier Bay National Park, take a look at the park service map. As recently as two hundred years ago, a massive ice field extended into Icy Strait and filled the Glacier Bay. Since that time, the area has experienced rapid deglaciation, with many large glaciers retreating 40, 60, even 80 km. While temperatures have increased in the region, it is still unclear whether the rapid recession is part of the natural cycle of tidewater glaciers or is an indicator of longer-term climate change. For more on Glacier Bay and climate change, read an online paper by Dr. Dorothy Hall, a MODIS Associate Science Team Member. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  11. Leaching of radionuclides from furfural-based polymers used to solidify reactor compartments and components disposed of in the Arctic Kara Sea

    SciTech Connect

    HEISER,J.H.; SIVINTSEV,Y.; ALEXANDROV,V.P.; DYER,R.S.

    1999-09-01

    Within the course of operating its nuclear navy, the former Soviet Union (FSU) disposed of reactor vessels and spent nuclear fuel (SNF) in three fjords on the east coast of Novaya Zemlya and in the open Kara Sea within the Novaya Zemlya Trough during the period 1965 to 1988. The dumping consisted of 16 reactors, six of which contained SNF and one special container that held ca. 60% of the damaged SNF and the screening assembly from the No. 2 reactor of the atomic icebreaker Lenin. At the time, the FSU considered dumping of decommissioned nuclear submarines with damaged cores in the bays of and near by the Novaya Zemlya archipelago in the Arctic Kara Sea to be acceptable. To provide an additional level of safety, a group of Russian scientists embarked upon a course of research to develop a solidification agent that would provide an ecologically safe barrier. The barrier material would prevent direct contact of seawater with the SNF and the resultant leaching and release of radionuclides. The solidification agent was to be introduced by flooding the reactors vessels and inner cavities. Once introduced the agent would harden and form an impermeable barrier. This report describes the sample preparation of several ``Furfurol'' compositions and their leach testing using cesium 137 as tracer.

  12. Island of Hawaii, Hawaiian Archipelago

    NASA Technical Reports Server (NTRS)

    1983-01-01

    This single photo covers almost all of the big island of Hawaii (19.5N, 155.5E) in the Hawaiian Archipelago. The active Kilauea Volcano and lava flow is under clouds and hardly visible at the lower right edge but the Mauna Loa volcano crater and its older lava flow is at the bottom center. The Kona Coast, that produces the only coffee grown in the United States, is to the left. Mauna Kea is the extinct volcano and lava flow in the right center.

  13. Island of Hawaii, Hawaiian Archipelago

    NASA Technical Reports Server (NTRS)

    1983-01-01

    This single photo covers almost all of the big island of Hawaii (19.5N, 155.5E) in the Hawaiian Archipelago. The active Kilauea Volcano and lava flow is under clouds and hardly visible at the lower right edge but the Mauna Loa volcano crater and its older lava flow is at the bottom center. The Kona Coast, that produces the only coffee grown in the United States, is to the left. Mauna Kea is the extinct volcano and lava flow in the right center.

  14. The mystery of Bunge Land (New Siberian Archipelago): implications for its formation based on palaeoenvironmental records, geomorphology, and remote sensing

    NASA Astrophysics Data System (ADS)

    Schirrmeister, Lutz; Grosse, Guido; Kunitsky, Viktor V.; Fuchs, Margret C.; Krbetschek, Matthias; Andreev, Andrei A.; Herzschuh, Ulrike; Babyi, Olga; Siegert, Christine; Meyer, Hanno; Derevyagin, Alexander Y.; Wetterich, Sebastian

    2010-12-01

    Multiproxy datasets (geocryology, geochronology, sedimentology, palaeo-ecology) from permafrost exposures were used together with land surface information based on satellite imagery and thematic maps in order to reconstruct the Lateglacial to Holocene landscape and environmental dynamics of Bunge Land (Zemlya Bunge). This area of little relief, situated in the New Siberian Archipelago, connects the geomorphologically well-structured islands of Kotel'ny and Fadeevsky. A buried thermokarst landscape was found in the northwest region of the Bunge Land low terrace sand plain, whereas the Bunge Land high terrace seems to be an exposed residue of a similar late Quaternary thermokarst landscape. That is confirmed especially by radiocarbon accelerator mass spectrometry and optically stimulated luminescence age determinations, and by pollen analyses. Palaeogeographically, the late Pleistocene periglacial landscape and sedimentation of Bunge Land was closely connected to Kotel'ny and Fadeevsky; only later on seismotectonical block movements resulted in reshaping parts of Bunge Land. The Bunge Land low terrace area first subsided and the original landscape there was destroyed by marine inundation, followed by marine sedimentation. Subsequent block heave of the low terrace region exposed a vast sheet of marine sands which is continuously surficially reworked by aeolian processes, while the original alluvial plain landscape in the high terrace area was preserved and started degrading only by early Holocene thermokarst development. The studied exposures contain one of the northernmost (74.88°N) environmental records for the late Pleistocene-Holocene transition in the Eurasian Arctic.

  15. Cossidae of the Socotra Archipelago (Yemen)

    PubMed Central

    Borth, Robert; Ivinskis, Povilas; Saldaitis, Aidas; Yakovlev, Roman

    2011-01-01

    Abstract The faunistic composition of the family Cossidae (Lepidoptera) of the Socotra Archipelago is revised. Five species are recognized, including two new species (Mormogystia brandstetteri and Meharia hackeri), and dubious identifications and records are discussed. Adults and genitalia are illustrated and bionomic details, DNA barcodes and a synonymic checklist for Socotran cossids are provided. A review of their distribution reveals that at least 80 percent of Socotra’s cossids are unique to the archipelago, which is renowned for its endemism. A checklist listing all the species from generas Meharia, Mormogystia, Aethalopteryx, Azygophleps, as well as the synonymy and distribution is provided. PMID:21998527

  16. Plant Conservation Challenges in the Bahama Archipelago

    USDA-ARS?s Scientific Manuscript database

    Technical Abstract The Bahamian archipelago has a rich flora with 89 endemic species. An international symposium held at Nassau in October 2012 to celebrate the 30th anniversary of the publication of the “Flora of the Bahama Archipelago” provided a forum to discuss plant conservation issues on these...

  17. The Alexander Archipelago wolf: a conservation assessment.

    Treesearch

    David K. Person; Matthew Kirchhoff; Victor van Ballenberghe; George C. Iverson; Edward. Grossman

    1996-01-01

    We summarized the scientific information available for the Alexander Archipelago wolf (Canis lupus ligoni) in the Tongass National Forest of southeast Alaska. Information concerning the morphology, distribution, taxonomy, genetics, and ecology of wolves are presented. Three issues for the conservation of wolves in southeast Alaska are discussed:...

  18. Shear Wave Splitting Beneath the Galapagos Archipelago

    NASA Astrophysics Data System (ADS)

    Fontaine, F. R.; Burkett, P. G.; Hooft, E. E.; Toomey, D. R.; Solomon, S. C.; Silver, P. G.

    2004-12-01

    We report measurements of teleseismic shear wave splitting in the Galápagos Archipelago. The inferred lateral variations in azimuthal anisotropy allow us to examine the dynamics of an evolving hotspot-ridge system. The data are from SKS and SKKS phases, as well as S waves from deep sources, recorded by a relatively dense network of 10 portable broadband seismometers deployed from 1999 to 2003 for the IGUANA (Imaging Galápagos Upwelling and Neotectonics of the Archipelago) experiment and from the GSN broadband station in Santa Cruz (PAYG). We find a delay time between fast and slow shear waves of 0.4 to 0.9 s and fast polarization directions of N85-90° E beneath five stations at the leading and southern edge of the archipelago. Despite clear seismic signals, we did not find any anisotropy at the six stations located in the interior of the archipelago. For those stations that show shear wave splitting, there is an increase in the delay time toward the expected location of the Galápagos hotspot at the western edge of the archipelago. With the exception of Española, fast polarization directions (N85-90° E) are close to the current direction of absolute plate motion of the overlying Nazca plate (N91° E). The lack of azimuthal anisotropy in the interior of the archipelago is interpreted as an absence of strongly oriented mantle fabric beneath these stations. The apparent isotropy in this dynamic region, where we expect considerable mantle strain, is surprising. It is not likely that the olivine a-axis is oriented vertically beneath the interior of the archipelago as the Galápagos plume is thought to lie at the western edge. It is also unlikely that there are two layers of perpendicularly-oriented anisotropy which are solely confined to the center of the archipelago. However, there appears to be some correlation between the region of apparent isotropy and a zone of anomalously low upper mantle velocities imaged beneath Santiago and Marchena from surface waves by

  19. Archipelago strait exchange processes—an overview

    NASA Astrophysics Data System (ADS)

    Engqvist, A.; Stenström, P.

    2004-02-01

    Archipelagos consist of a set of islands forming a collection of basins interconnected by straits, and are typically characterized by widely varying spatial and temporal scales regarding geometry and forcing conditions. Focusing on the strait exchange parameterization, we describe an archipelago water exchange model in which the archipelago is subdivided into a network of discrete basins and interconnecting straits and where the time integration assumes a series of quasi-steady states. We propose an algorithm that should be sufficiently flexible to provide reasonable strait exchange estimates under the variety of forcing conditions encountered in the Stockholm archipelago. We start from the functional formulation of two-layer hydraulic theory, which allows numerical schemes to be designed that, given the forcing conditions at the ends of a given strait, distinguish between maximal and sub-maximal flow cases and solve the flow accordingly. We relax the assumption of two homogeneous layers when necessary, using an approximate method based on a self-similarity assumption and with the sea-level difference over the strait as an explicit part of the problem. This method allows exchange flows with two groups of layers to be solved for the same set of geometries that the pure two-layer theory can handle, including sill-contraction combinations and non-rectangular cross-sections. We further show how aspiration of dense water from below the sill crest can be quantified with hydraulic theory, and be included in the method for stratified strait exchange. Rotational control in wide straits and in parallel straits connecting the same two basins is treated with a simple but robust scheme. We evaluate the calculations with data from the Oxdjupet strait in the Stockholm archipelago. Simulations with a three-dimensional, non-hydrostatic numerical model are performed to compensate for sparsity in data.

  20. Tenarife Island, Canary Island Archipelago, Atlantic Ocean

    NASA Image and Video Library

    1991-08-11

    Tenarife Island is one of the most volcanically active of the Canary Island archipelago, Atlantic Ocean, just off the NW coast of Africa, (28.5N, 16.5W). The old central caldera, nearly filled in by successive volcanic activity culminating in two stratocones. From those two peaks, a line of smaller cinder cones extend to the point of the island. Extensive gullies dissect the west side of the island and some forests still remain on the east side.

  1. Aldabra Islands, Seychelle Archipelago, Indian Ocean

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Aldabra Islands, two coral atolls of the Seychelle Archipelago (9.5S, 46.5E) in the Indian Ocean, because of their remotness, have a rare ecosystem almost completely untouched by outside influences. About 10 % of the plant and animal life is unique to the atolls and therefore, development of the area has been barred. Assumption, the smaller atoll has a small aircraft runway to support occasional environmental or scientific survey teams.

  2. Modeled Population Connectivity across the Hawaiian Archipelago

    PubMed Central

    Wren, Johanna L. K.; Kobayashi, Donald R.; Jia, Yanli; Toonen, Robert J.

    2016-01-01

    We present the first comprehensive estimate of connectivity of passive pelagic particles released from coral reef habitat throughout the Hawaiian Archipelago. Potential connectivity is calculated using a Lagrangian particle transport model coupled offline with currents generated by an oceanographic circulation model, MITgcm. The connectivity matrices show a surprising degree of self-recruitment and directional dispersal towards the northwest, from the Main Hawaiian Islands (MHI) to the northwestern Hawaiian Islands (NWHI). We identify three predicted connectivity breaks in the archipelago, that is, areas in the mid and northern part of the archipelago that have limited connections with surrounding islands and reefs. Predicted regions of limited connectivity generally match observed patterns of genetic structure reported for coral reef species in the uninhabited NWHI, but multiple genetic breaks observed in the inhabited MHI are not explained by passive dispersal. The better congruence in our modeling results based on physical transport of passive particles in the low-lying atolls of the uninhabited NWHI, but not in the anthropogenically impacted high islands of the MHI begs the question: what ultimately controls connectivity in this system? PMID:27930680

  3. Modeled Population Connectivity across the Hawaiian Archipelago.

    PubMed

    Wren, Johanna L K; Kobayashi, Donald R; Jia, Yanli; Toonen, Robert J

    2016-01-01

    We present the first comprehensive estimate of connectivity of passive pelagic particles released from coral reef habitat throughout the Hawaiian Archipelago. Potential connectivity is calculated using a Lagrangian particle transport model coupled offline with currents generated by an oceanographic circulation model, MITgcm. The connectivity matrices show a surprising degree of self-recruitment and directional dispersal towards the northwest, from the Main Hawaiian Islands (MHI) to the northwestern Hawaiian Islands (NWHI). We identify three predicted connectivity breaks in the archipelago, that is, areas in the mid and northern part of the archipelago that have limited connections with surrounding islands and reefs. Predicted regions of limited connectivity generally match observed patterns of genetic structure reported for coral reef species in the uninhabited NWHI, but multiple genetic breaks observed in the inhabited MHI are not explained by passive dispersal. The better congruence in our modeling results based on physical transport of passive particles in the low-lying atolls of the uninhabited NWHI, but not in the anthropogenically impacted high islands of the MHI begs the question: what ultimately controls connectivity in this system?

  4. [Leprosy in the French Polynesian archipelagoes from 1967 to 1987].

    PubMed

    Cartel, J L; Boutin, J P; Plichart, R; Roux, J; Grosset, J H

    1988-01-01

    Between 1967 and 1987, 255 new cases of leprosy were detected in French Polynesia (FP) that means on average a 8.6% detection rate. Average detection rate calculated in 7 three-year periods did not vary significantly during the 21 years studied period of time. In two remote archipelagoes of FP average detection rate of leprosy is specially high: Gambier archipelago and Southern Marquesas archipelago with respectively a 54.7 and a 48.9% detection rate. To control leprosy, the network of treatment and active case-finding should be strengthened in archipelagoes and chemoprophylaxis programmes could be planned in places where the problem is especially important.

  5. Seroprevalence of Toxoplasma gondii in seabirds from Abrolhos Archipelago, Brazil

    USDA-ARS?s Scientific Manuscript database

    Toxoplasma gondii is a coccidian parasite that infects almost all warm-blooded animals, including birds. Abrolhos is an archipelago of five islands, located in the Atlantic Ocean, 56 nautical kilometers from the south coast of the state of Bahia, northeastern Brazil. Part of this archipelago is a Na...

  6. Tongue of the ocean, Bahamas Archipelago

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A portion of the tongue of the ocean (24.0N, 77.0W), and the Bahamas Bank, Bahamas Archipelago. The light blue region is the shalow sea bottom where the Bahama Bank is no more than 30 ft. deep. At the contact between light and dark blue, an underwater shear cliff drops over a mile in depth. The wavey lines of various shades of blue are caused by the differential coral growth relative to the warm/cool water transfer in and out of the tongue.

  7. Water Quality Modeling System for Coastal Archipelagos

    NASA Astrophysics Data System (ADS)

    Tuomi, L.; Miettunen, E.; Lukkari, K.; Puttonen, I.; Ropponen, J.; Tikka, K.; Piiparinen, J.; Lignell, R.

    2016-02-01

    Coastal seas are encountering pressures from eutrophication, fishing, ship emissions and coastal construction. Sustainable development and use of these areas require science-based guidance with high quality data and efficient tools. Our study area, the Archipelago Sea, is located in the northern part of the semi-enclosed and brackish water Baltic Sea. It is a shallow, topographically heterogeneous and eutrophic sub-basin, covered with thousands of small islands and islets. The catchment area is 8950 km2and has ca. 500 000 inhabitants. We are developing a modeling system that can be used by local authorities and in ministry level decision making to evaluate the environmental impacts that may result from decisions and changes made both in the watershed and in the coastal areas. The modeling system consists of 3D hydrodynamic model COHERENS and water quality model FICOS, both applied to the area with high spatial resolution. Models use river discharge and nutrient loading data supplied by watershed model VEMALA and include loading from multiple point sources located in the Archipelago Sea. An easy-to-use interface made specifically to answer the end-user needs, includes possibility to modify the nutrient loadings and perform model simulations to selected areas and time periods. To ensure the quality and performance of the modeling system, comprehensive measurement dataset including hydrographic, nutrient, chlorophyll-a and bottom sediment data, was gathered based on monitoring and research campaigns previously carried out in the Archipelago Sea. Verification showed that hydrodynamic model was able to simulate surface temperature and salinity fields and their seasonal variation with good accuracy in this complex area. However, the dynamics of the deeper layers need to be improved, especially in areas that have sharp bathymetric gradients. The preliminary analysis of the water quality model results showed that the model was able to reproduce the basic characteristics of

  8. Ice Mass Changes in the Russian High Arctic

    NASA Astrophysics Data System (ADS)

    Willis, M. J.; Melkonian, A. K.; Pritchard, M. E.; Golos, E. M.

    2012-12-01

    The ~2000 glaciers and icecaps on the islands of the Russian High Arctic cover a total area of about 55,600 km2. Infrequent studies have indicated that these glaciers have lost a total of ~100 km3 of ice, equivalent to about 0.3 mm of sea level, since 1960. Recent GRACE observations suggest that the Severnaya Zemlya Archipelago and Franz Josef Archipelago are approximately in balance, while the "Main Ice Sheet" of the Novaya Zemlya archipelago is losing mass at a small rate. This glacier complex, on the northern island of the archipelago is the largest ice mass in Europe (23,800 km2) and the third largest polar ice masses on the planet after the Antarctic and Greenland Ice sheets. The glaciers, ice caps and icefields of the Russian High Arctic are a major reservoir of fresh water and under climate scenarios that involve warming, a potentially increasing source of mass for sea level rise. We examine the response of the glaciers of the Russian High Arctic to recent, pronounced atmospheric warming. Digitized topographic maps, ASTER Digital Elevation Models (DEMs), cloud free ICESat returns and several DEMs calculated from recent high-resolution imagery pairs are used to provide a time-series and maps of ice surface elevation change rates between the mid-1980s' and 2012 for the "Main Ice Sheet" on Novaya Zemlya and the Franz Josef Land Archipelago. DEMs are co-registered to a common horizontal base and corrected for biases due to varying reference frames and datums. Elevation change rates are calculated on a pixel-by-pixel basis and are integrated over each ice complex to provide volume change rates. Volume rates are converted to mass rates assuming an ice density of 900 kg/m3. Glacier speeds are derived from pairs of ASTER images between 2000 and 2012 and from higher resolution imagery between 2010 and 2012. Cloudy conditions often hamper our ability to make good pairs and problems occur when there are no bedrock outcrops, which are typically used to check for

  9. Species-area relation for birds of the Solomon Archipelago

    PubMed Central

    Diamond, Jared M.; Mayr, Ernst

    1976-01-01

    Accurate values of number of breeding bird species have been obtained for 50 islands of the Solomon Archipelago. From information about species altitudinal distributions on each island, the values are apportioned into number of montane species (Smt) and of species present at sea-level (Slow). Slow increases linearly with the logarithm of island area A over a million-fold range of areas (correlation coefficient 0.99) and with a comparatively low slope, while the log S-log A relation is markedly curved. With increasing isolation of an archipelago, the species-area relation decreases in slope and may shift in form from a power function to an exponential. Comparison of Pacific archipelagoes at different distances from the colonization source of New Guinea shows that the decrease in slope is due to increasing intra-archipelago immigration rates, arising from overrepresentation of the most vagile inter-archipelago immigrants in more distant archipelagoes. When colonists are sorted into sets correlated with their dispersal abilities, the slope of the species-area relation for the most vagile set is close to zero, but for the least vagile set is close to the value predicted by Preston for “isolated universes.” PMID:16592301

  10. Species-area relation for birds of the Solomon Archipelago.

    PubMed

    Diamond, J M; Mayr, E

    1976-01-01

    Accurate values of number of breeding bird species have been obtained for 50 islands of the Solomon Archipelago. From information about species altitudinal distributions on each island, the values are apportioned into number of montane species (S(mt)) and of species present at sea-level (S(low)). S(low) increases linearly with the logarithm of island area A over a million-fold range of areas (correlation coefficient 0.99) and with a comparatively low slope, while the log S-log A relation is markedly curved. With increasing isolation of an archipelago, the species-area relation decreases in slope and may shift in form from a power function to an exponential. Comparison of Pacific archipelagoes at different distances from the colonization source of New Guinea shows that the decrease in slope is due to increasing intra-archipelago immigration rates, arising from overrepresentation of the most vagile inter-archipelago immigrants in more distant archipelagoes. When colonists are sorted into sets correlated with their dispersal abilities, the slope of the species-area relation for the most vagile set is close to zero, but for the least vagile set is close to the value predicted by Preston for "isolated universes."

  11. Nematodes from terrestrial and freshwater habitats in the Arctic.

    PubMed

    Holovachov, Oleksandr

    2014-01-01

    WE PRESENT AN UPDATED LIST OF TERRESTRIAL AND FRESHWATER NEMATODES FROM ALL REGIONS OF THE ARCTIC, FOR WHICH RECORDS OF PROPERLY IDENTIFIED NEMATODE SPECIES ARE AVAILABLE: Svalbard, Jan Mayen, Iceland, Greenland, Nunavut, Northwest territories, Alaska, Lena River estuary, Taymyr and Severnaya Zemlya and Novaya Zemlya. The list includes 391 species belonging to 146 genera, 54 families and 10 orders of the phylum Nematoda.

  12. Historical tsunami in the Azores archipelago (Portugal)

    NASA Astrophysics Data System (ADS)

    Andrade, C.; Borges, P.; Freitas, M. C.

    2006-08-01

    Because of its exposed northern mid-Atlantic location, morphology and plate-tectonics setting, the Azores Archipelago is highly vulnerable to tsunami hazards associated with landslides and seismic or volcanic triggers, local or distal. Critical examination of available data - written accounts and geologic evidence - indicates that, since the settlement of the archipelago in the 15th century, at least 23 tsunami have struck Azorean coastal zones. Most of the recorded tsunami are generated by earthquakes. The highest known run-up (11-15 m) was recorded on 1 November 1755 at Terceira Island, corresponding to an event of intensity VII-VIII (damaging-heavily damaging) on the Papadopolous-Imamura scale. To date, eruptive activity, while relatively frequent in the Azores, does not appear to have generated destructive tsunami. However, this apparent paucity of volcanogenic tsunami in the historical record may be misleading because of limited instrumental and documentary data, and small source-volumes released during historical eruptions. The latter are in contrast with the geological record of massive pyroclastic flows and caldera explosions with potential to generate high-magnitude tsunami, predating settlement. In addition, limited evidence suggests that submarine landslides from unstable volcano flanks may have also triggered some damaging tsunamigenic floods that perhaps were erroneously attributed to intense storms. The lack of destructive tsunami since the mid-18th century has led to governmental complacency and public disinterest in the Azores, as demonstrated by the fact that existing emergency regulations concerning seismic events in the Azores Autonomous Region make no mention of tsunami and their attendant hazards. We suspect that the coastal fringe of the Azores may well preserve a sedimentary record of some past tsunamigenic flooding events. Geological field studies must be accelerated to expand the existing database to include prehistoric events

  13. Hydrogeology of the Azores volcanic archipelago (Portugal)

    NASA Astrophysics Data System (ADS)

    Cruz, J.; Coutinho, R.; Antunes, P.; Freire, P.

    2009-04-01

    The archipelago of the Azores is made of nine islands of volcanic origin located in the North Atlantic Ocean, with an area of 2333 km2 and approximately 237500 inhabitants, which are 98% dependant from groundwater sources for their water consumption. Therefore, groundwater is a resource that plays a vital role as drinking water source and as ecosystem support matrix. Nevertheless, besides the environmental, social and economical value of groundwater, this resource is subject to an increase pressure and in several islands water quality deterioration is shown by monitoring data. This pressure is also shown by the 42.7% increase expected for domestic use until the year 2020 at the Azores, with higher groundwater abstraction. The Azores climate can be considered as marine temperate, which is reflected by the low thermal amplitude and high precipitation. A well-established difference between a dry season and a colder and wet season occurs, as from October to March about 75% of the annual precipitation is registered. The average annual precipitation at the Azores is 1930 mm, exceeding by far the average annual actual evapotranspiration, which is 581 mm. Recharge rates range from 8.5% to 62.1%, and the highest values are observed at Pico, Terceira, Faial, São Miguel and Graciosa islands, especially in areas where the terrain is covered by recent basaltic lava flows and the soil cover is sparse. Groundwater resources estimates point to a total volume of about 1600x106 m3/yr. Values above the recharge median, equal to 101.3x106 m3/yr. were estimated for the São Miguel, São Jorge, Terceira and Flores islands. Despite differences in the islands growth, as a result of successive volcanic eruptions of various types, groundwater occurrence can be described in function of two main aquifers systems: (1) the basal aquifer system, which corresponds to fresh-water lenses floating on underlying salt water, and (2) perched-water bodies, which are usually drained by springs spread in

  14. Some features of the technogenic pollution of the Kara Sea, with the example of the sunken nuclear submarine K-27

    NASA Astrophysics Data System (ADS)

    Dmitrievskiy, N. N.; Nikiforov, S. L.; Lobkovsky, L. I.; Ananiev, R. A.

    2015-11-01

    This article discusses the results of offshore operations undertaken during a cruise of the R/V Professor Shtokman (2013) during an expedition in the fjord Stepovoi of the Novaya Zemlya Archipelago k]where the nuclear submarine (NPS) K-27 was scuttled in 1981 k]An echo sounding of her hull showed signs of water destratification k]which may be caused by turbulence from gas or heat flows outgoing from the hull k]According to the hypothesis of the author k]the presence of the reactors and radioactive nuclear fuel remnants may lead to the continued heating of the inner cavities of the submarine and k]as a consequence k]to constant heat flow from its surface k]which is an obvious danger k]including risks associated with plans to refloat and transport the submarine for the further dismantlement.

  15. Thinking Strategically in the Aleutian Archipelago

    NASA Astrophysics Data System (ADS)

    Robards, M.; Burn, D. M.; Poe, A.

    2016-02-01

    Each year, thousands of deep-draft vessels transit through the Aleutians along shipping routes between North America and Asia. In December 2004 the M/V Selendang Ayu, a 740-foot bulk carrier, lost power and drifted aground on the north shore of Unalaska Island in the eastern Aleutians. The vessel was broken in two, spilling over 300,000 gallons of heavy fuel oil and cargo of soybeans. The resulting disaster claimed the lives of six crewmen, as well as thousands of seabirds and at least six sea otters. Our comprehensive analysis of North Pacific shipping routes through application of data from the Automatic Identification System (mandated by the International Maritime Organization for these deep-draft vessels), has documented that many of these ships pass perilously close to several of the Aleutian islands. Our results helped inform a proposal by the U.S. Coast Guard to the International Maritime Organization for the establishment of five Areas to be Avoided (ATBAs) in the Aleutians. These ATBAs would apply to ships 400 gross tons and heavier, transiting on the Great Circle Route on either the north or south side of the Aleutian archipelago. The proposal was approved by the IMO in June 2015 and takes effect on January 1, 2016. Further analysis of new vessel routes that would conform to the proposed ATBAs using distance as a proxy for exposure indicates that the new routes would reduce potential risk to seabird colonies by 17% and to endangered Steller sea lions at haulouts and rookeries by 21%, while adding less than 1% to the overall length of the voyage between the two continents. Additional analysis supported by the ABSI/WCS partnership will identify areas most at risk to vessel drift groundings, which can inform spill response preparation efforts. There are enormous economic benefits for vessel operators to reduce the risk of impacts to natural resources such as marine mammals and seabirds.

  16. Glacier surface melt characterization and trend analysis (1992-2011) in the Russian High Arctic from combined resolution-enhanced scatterometer and passive microwave data

    NASA Astrophysics Data System (ADS)

    Zhao, M.; Ramage, J. M.; Semmens, K. A.

    2012-12-01

    Global warming has been pronounced in the remote glacierized archipelagoes (Severnaya Zemlya, Novaya Zemlya and Franz Josef Land) of the Russian High Arctic (RHA) and its effect on the low altitude, high latitude small ice caps needs examination. The timing and spatial variability of snow melt onset, duration and intensity are key factors influencing mass balance and the ice marginal hydrological system as well as important indicators of glacial response to anthropogenic and natural forcings. Characterization and trend analysis of RHA glacier melt behaviors provide insight about assessing the mass loss rate under recent Arctic climate change. However, due to the harsh environment, long term records of glaciological data for RHA are limited, necessitating the application of remotely sensed data to accomplish the research. The high sensitivity to liquid water and the ability to penetrate non-precipitating clouds enables microwave remote sensing to detect glacier surface melt. The appearance of melt water in snow dramatically decreases the returned scatterometer radar signal from active microwave sensors and sharply augments passive microwave emission. Based on this feature, we combined resolution-enhanced ERS-1/2 C-band (1992-2000), QuickSCAT Ku-band (2000-2009), ASCAT C-band (2009-2011) scatterometer data and SSMI 37 GHz (1995-2007) vertically polarized passive microwave products from Brigham Young University and analyzed glacier surface melt trends from 1992 to 2011 with a spatial resolution downscaled to 4.45km. We concatenated scatterometer derived melt behaviors by overlapping years and refined the results based on passive microwave data. Cross-validation shows that melt timing to be consistent between the active and passive sensors. Trend analysis (α < 0.005) reveals that the average glacier surface melt onset date occurs earlier by approximately 0.85 days/year in Severnaya Zemlya which outpaced the mean advancing rate in the pan-Arctic. Surrounded by ocean

  17. Herpetology of the American Madrean Archipelago and adjacent valleys

    Treesearch

    Lawrence L. C. Jones

    2005-01-01

    Approximately 110 species of amphibians (18 frogs and toads, and 1 salamander) and reptiles (47 snakes, 39 lizards, and 5 turtles) are known from the American Madrean Archipelago and adjacent valleys. The high diversity of the herpetofauna comes from a variety of factors, including a convergence of biotic communities representing deserts, grasslands, and mountains....

  18. Professional Development through Collaborative Inquiry for an Art Education Archipelago

    ERIC Educational Resources Information Center

    Gates, Leslie

    2010-01-01

    The culture of isolation in schools leaves many art educators feeling that they are, in a sense, islands. Working from the idea of an island, I use the geographic metaphor of an archipelago as a means to understand the tensions between isolation and collaboration related to professional development for art educators. In this article, I describe…

  19. Estimates of Canadian Arctic Archipelago runoff from observed hydrometric data

    NASA Astrophysics Data System (ADS)

    Spence, Christopher; Burke, Amanda

    2008-12-01

    SummarySmall basin studies in the remote Canadian Arctic Archipelago have revealed the general nature of runoff processes and the annual rhythms and magnitude of streamflow in the region, but widespread monitoring of hydrological cycle components is absent. The result is that an understanding of large scale freshwater fluxes from the Arctic Archipelago does not exist. Such understanding is important for sound domestic water management decisions and international obligations to quantify Canada's freshwater supply to the oceans. The study summarized by this paper, initiated under the auspices of the International Polar Year, extrapolated observed streamflow attributes across the Arctic Archipelago using statistical regionalization tools. The paucity of hydrometric data necessitated the construction of a dataset, which was limited to the period from 1972 to 1994. Reliable estimates of mean May-October freshwater flux were possible from ˜70% of the Archipelago and these total ˜190 km 3. Maximum daily runoff can be up to 13% of the total annual flux from some catchments. Flows were highest from southern Baffin Island, decreasing westward. The scarcity of data compelled an error analysis that showed average confidence intervals around constructed and regionalized data of ±123% and ±63%, respectively. Dataset construction errors were inversely related to basin area. There was no spatial pattern to the dataset construction errors, but regionalization error tended to be higher in the west. It will be argued that our community has little to no idea of the current freshwater flux from the Arctic Archipelago, or if it is changing. Much work is needed to improve these estimates, including establishing a sustainable, effective and efficient monitoring and research program of high arctic freshwater systems that can build upon the legacy of the International Polar Year.

  20. Ice core from Akademii Nauk ice cap, Severnaya Zemlya (Russian Arctic), dated with a Nye model modified for a growing glacier

    NASA Astrophysics Data System (ADS)

    Fritzsche, Diedrich; Opel, Thomas; Meyer, Hanno

    2010-05-01

    From 1999 to 2001 a 724 m deep ice core has been drilled from surface to bedrock close to summit of the Akademii Nauk ice cap, Severnaya Zemlya (Russian Arctic), within a joint German-Russian project. The analysis of stable water isotopes and major ion concentration in high resolution were used for reconstruction of past climate and environmental changes. The upper 304 m of the core were dated by counting annual stable isotope cycles considering radioactive (1986, 1963) and volcanic events (1956, 1912, 1783, 1259) as reference horizons. The resulting depth-age relationship and the corresponding annual-layer thickness imply that the ice cap was not in dynamic steady state but had been growing until recent times. That does not comply with requirements of a standard Nye or Dansgaard-Johnson flow model approach. To take into account the peculiarities of Akademii Nauk ice cap a Nye model was modified by adding a growing term according to the found relationship between annual layer thickness and depth. Using the volcanoes identified an average increase of altitude of about 0.08 m w.e. per year was calculated since AD 1259. The model enables us to reconstruct the altitude changes of the ice cap with time and to consider an altitude effect to correct the stable isotope values and to explain decreasing sea-salt ion data. Using the suggested model annual layer thickness can be decompressed to accumulation rates at the altitude where the precipitation was originally deposited. The model can also be used for dating deeper parts of ice core where volcanoes are not identified up to now. Applying this model, the ice core has an age of about 2 500 years, much less than claimed for an older core from Akademii Nauk ice cap. Consequently, the ice cap is much younger and only of Late Holocene age, as also assumed for most Arctic ice caps and glaciers outside Greenland. However, the lowest part of Akademii Nauk ice cap is probably a remnant of an older ice cap stage.

  1. Pelagic microplastics around an archipelago of the Equatorial Atlantic.

    PubMed

    Ivar do Sul, Juliana A; Costa, Monica F; Barletta, Mário; Cysneiros, Francisco José A

    2013-10-15

    Plastic marine debris is presently widely recognised as an important environmental pollutant. Such debris is reported in every habitat of the oceans, from urban tourist beaches to remote islands and from the ocean surface to submarine canyons, and is found buried and deposited on sandy and cobble beaches. Plastic marine debris varies from micrometres to several metres in length and is potentially ingested by animals of every level of the marine food web. Here, we show that synthetic polymers are present in subsurface plankton samples around Saint Peter and Saint Paul Archipelago in the Equatorial Atlantic Ocean. To explain the distribution of microplastics around the Archipelago, we proposed a generalised linear model (GLM) that suggests the existence of an outward gradient of mean plastic-particle densities. Plastic items can be autochthonous or transported over large oceanic distances. One probable source is the small but persistent fishing fleet using the area.

  2. Predicting coral recruitment in Palau's complex reef archipelago.

    PubMed

    Golbuu, Yimnang; Wolanski, Eric; Idechong, Jacques Wasai; Victor, Steven; Isechal, Adelle Lukes; Oldiais, Noelle Wenty; Idip, David; Richmond, Robert H; van Woesik, Robert

    2012-01-01

    Reproduction and recruitment are key processes that replenish marine populations. Here we use the Palau archipelago, in the western Pacific Ocean, as a case study to examine scales of connectivity and to determine whether an oceanographic model, incorporating the complex reef architecture, is a useful predictor of coral recruitment. We tested the hypothesis that the reefs with the highest retention also had the highest densities of juvenile coral density from 80 field sites. Field comparisons showed a significant correlation between the densities of juvenile Acropora colonies and total larval recruitment derived from the model (i.e., calculated as the sum of the densities of larvae that self-seeded and recruited from the other reefs in the archipelago). Long-distance larval imports may be too infrequent to sustain coral populations, but are critical for recovery in times of extreme local stress.

  3. Predicting Coral Recruitment in Palau’s Complex Reef Archipelago

    PubMed Central

    Golbuu, Yimnang; Wolanski, Eric; Idechong, Jacques Wasai; Victor, Steven; Isechal, Adelle Lukes; Oldiais, Noelle Wenty; Idip, David; Richmond, Robert H.; van Woesik, Robert

    2012-01-01

    Reproduction and recruitment are key processes that replenish marine populations. Here we use the Palau archipelago, in the western Pacific Ocean, as a case study to examine scales of connectivity and to determine whether an oceanographic model, incorporating the complex reef architecture, is a useful predictor of coral recruitment. We tested the hypothesis that the reefs with the highest retention also had the highest densities of juvenile coral density from 80 field sites. Field comparisons showed a significant correlation between the densities of juvenile Acropora colonies and total larval recruitment derived from the model (i.e., calculated as the sum of the densities of larvae that self-seeded and recruited from the other reefs in the archipelago). Long-distance larval imports may be too infrequent to sustain coral populations, but are critical for recovery in times of extreme local stress. PMID:23209842

  4. Contribution to the Pteridophyte Flora of Langkawi Archipelago, Peninsular Malaysia

    PubMed Central

    Maideen, Haja; Damanhuri, Ahmad

    2015-01-01

    The pteridophyte flora of Langkawi Archipelago consists of 130 species, 1 subspecies and 12 varieties in 68 genera and 27 families. This value represents 22.1% of the 647 taxa at the species level and below reported for Peninsular Malaysia. Of the 143 recorded taxa of pteridophytes at the species level and below, 8 species in 2 genera and 2 families are lycophytes and the other 135 taxa in 66 genera and 25 families are monilophytes or ferns. PMID:26868714

  5. Archipelago Tidal Flats in Korea: Sedimentological and Geoheritage Significance

    NASA Astrophysics Data System (ADS)

    Woo, Kyung Sik; Chun, SeungSoo; Moon, Kyong O.

    2015-04-01

    Over one thousand islands with rocky shores are distributed and concentrated along the southwestern coast of the Korean Peninsula. Various tidal flats formed along the rocky coasts of the archipelago have been developed due to the relative decrease in accommodation space by slow sea-level rise on broad marginal epicontinental seas during the Holocene. Sedimentation and evolution on these archipelago tidal flats (ATF) show quite distinctive and various tidal flat patterns, depending upon the location and direction of rocky shores which have been constantly influenced by monsoon winds reversely changing with season. Generally ATF is characterized by surrounding wave-dominated sand flats along the outside of the archipelago and by broad tide-dominated mud flats in its central part with spring tidal range reaching up to 6 meters. The open-coast outside sand flats and inner mud flats are completely different in terms of sedimentation and the evolution of sedimentary sequences. The former has been deposited by the transgressive sedimentation with strongly destructive and weakly constructive wave/tide processes, forming relative thin and younger (ca. 3,000 yrs BP) remnant storm-dominated sandflat units. The latter has been deposited by continuous transgressive settling with constructive tidal processes during Holocene, forming relative thick and older (from ca. 7,000 yrs BP) mud-flat units. Geomorphological features and the geological evolution of the ATF (Shinan archipelago and Yoobudo islands in Seocheon) display a quite distinctive pattern of ongoing geological processes from the Wadden Sea tidal flats which was already inscribed as World Natural Heritage. Therefore, the Outstanding Universal Values of the Korean ITF for criteria (vii) and (viii) should provide a strong support for the additional World Natural Heritage Site.

  6. mtDNA microevolution in Southern Chile's archipelagos.

    PubMed

    García, Federico; Moraga, Mauricio; Vera, Soledad; Henríquez, Hugo; Llop, Elena; Aspillaga, Eugenio; Rothhammer, Francisco

    2006-03-01

    The genetic variability of four predominantly Indian populations of southern Chile's archipelagos was examined by determining the frequencies of four mitochondrial DNA haplogroups that characterize the American Indian populations. Over 90% of the individuals analyzed presented Native American mtDNA haplogroups. By means of an unweighted group pair method with arithmetic mean (UPGMA) dendrogram, a principal component analysis (PCA) derived from a distance matrix of mtDNA, and the exact test of population differentiation, we are able to prove the existence of a North-South cline. The populations in the northern part of the archipelagos are genetically similar to the Huilliche tribe, while the groups from the South are most closely related to the Fueguino tribe from the extreme South of Chile, and secondarily to the Pehuenche and Mapuche, who are found to the North and East of Chiloé archipelago. These results are consistent with a colonization of the southern archipelagos from Tierra del Fuego. We evaluate the evolutionary relationships of the population of the Chiloé area to groups from other geographic areas of Chile, using analysis of molecular variance (AMOVA). Three Amerindian clusters are identified: one formed by the Aymará and Atacameño, a second by the Huilliche, and a third including the Mapuche, Pehuenche, and Fueguino tribes, and the population inhabiting the South of the Chiloé arcipelago. These groups exhibit a North-South gradient in the frequency of haplogroup B, confirmed by F(ST) tests. (c) 2005 Wiley-Liss, Inc.

  7. Sea otter population declines in the Aleutian Archipelago

    USGS Publications Warehouse

    Doroff, Angela; Estes, James A.; Tinker, M. Tim; Burn, Douglas M.; Evans, Thomas J.

    2003-01-01

    Sea otter (Enhydra lutris) populations were exploited to near extinction and began to recover after the cessation of commercial hunting in 1911. Remnant colonies of sea otters in the Aleutian archipelago were among the first to recover; they continued to increase through the 1980s but declined abruptly during the 1990s. We conducted an aerial survey of the Aleutian archipelago in 2000 and compared results with similar surveys conducted in 1965 and 1992. The number of sea otters counted decreased by 75% between 1965 and 2000; 88% for islands at equilibrial density in 1965. The population decline likely began in the mid-1980s and declined at a rate of 17.5%/year in the 1990s. The minimal population estimate was 8,742 sea otters in 2000. The population declined to a uniformly low density in the archipelago, suggesting a common and geographically widespread cause. These data are in general agreement with the hypothesis of increased predation on sea otters. These data chronicle one of the most widespread and precipitous population declines for a mammalian carnivore in recorded history.

  8. Seroprevalence of Toxoplasma gondii in seabirds from Abrolhos Archipelago, Brazil.

    PubMed

    Gennari, Solange M; Niemeyer, Claudia; Soares, Herbert S; Musso, Cesar M; Siqueira, Glauber C C; Catão-Dias, José L; Dias, Ricardo A; Dubey, Jitender P

    2016-08-15

    Toxoplasma gondii is a coccidian parasite that infects almost all warm-blooded animals, including birds. Abrolhos is an archipelago of five islands, located in the Atlantic Ocean, 56 nautical kilometers from the south coast of the state of Bahia, northeastern Brazil. Part of this archipelago is a National Marine Park, which is a conservation area protected by the Brazilian government. The objective of this study was to determine the occurrence of T. gondii antibodies in sera of seabird's species Sula spp. and Phaeton spp. from breeding colonies located in the Islands of Santa Bárbara and Redonda, Abrolhos's archipelago. Sera were tested by modified agglutination test, first screened at 1:5 dilution (cut-off point) and the positive samples were titrated at a two-fold serial dilution. Serum samples were obtained from 69 birds of four species: Sula dactylatra (23 birds), Sula leucogaster (19 birds), Phaeton aethereus (25 birds) and Phaeton lepturus (2 birds). Antibodies to T. gondii were found in 24 (34.8%) of 69 seabirds with titers that ranged from 5 to 640. Occurrence value in S. dactylatra was 34.8% (8/23), in S. leucogaster was 47.4% (9/19), in P. aethereus was 28% (7/25) and the 2 P. lepturus were negative. This is the first description of T. gondii antibodies in free ranging seabirds of the orders Suliformes and Phaethontiformes. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. To the knowledge of cuckoo wasps (Hymenoptera: Chrysididae) of the Balearic Archipelago, Spain.

    PubMed

    Strumia, Franco; Gayubo, Severiano Fernández

    2013-01-01

    The Chrysididae of the Balearic Archipelago were studied by operating four Malaise traps in the Mallorca and Menorca Islands. Traps captured 98 individuals belonging to 19 species. Including all available data from literature, the number of species in this archipelago rise to 34. Hedychridium balearicum Strumia, sp. nov (Mallorca) is described and key to the Hedychridium monochroum species-group is given. Extrapolation from available data suggests the presence of about 58 to 107 Chrysididae species in the Balearic Archipelago.

  10. [A comparative analysis of the helminth fauna of kittiwake Rissa tridactyla (Linnaeus, 1758) and glaucous gull Larus hyperboreus Gunnerus, 1767 from different parts of the Barents Sea].

    PubMed

    Kuklin, V V; Galaktionov, K V; Galkin, A K; Marasaev, S F

    2005-01-01

    The article is based on the results of helminthological observations made on kittiwake Rissa tridactyla and glaucous gull Larus hyperboreus in 1991-2001 in different areas of the Barents Sea (Eastern Murman coast, Franz Josef Land, Novaya Zemlya, Spitzbergen). 18 helminth species (2 trematodes, 11 cestodes, 4 nematodes, and 2 acanthocephalans) were recorded in the kittiwakes and 19 (3 trematodes, 9 cestodes, 5 nematodes and 2 acanthocephalans) species were recorded in the glaucous gulls. Trematodes were absent in the birds collected at the Franz Josef Land and the northern island of Novaya Zemlya. 3 trematode species, namely Gymnophallus sp. (somateria?), Microphallus sp. 1 (M. pseudopygmaeus), and Cryptocotyle lingua were found in the glaucous gulls of western Spitzbergen. It was supposed that the life cycles of these parasites can be completed there. On the other hand, coastal ecosystems of Arctic archipelagoes turn out to be favourable for the transmission of some cestodes. This is closely connected with the regional traits in the marine bird diet, namely the increase of the amphipod (intermediate hosts of hymenolepidids and some dilepidids) and polar cod (supposed second intermediate host for some tetrabothriids) portion in Arctic. As a result, cestodes are the base of the helminth fauna of kittiwakes and glaucous gulls of the Barents Sea, by their species richness, prevalence and abundance. Nematodes and acanthocephalans were represented by a few species with low infection intensity. The main ecological factors affected the regional difference in the species richness and abundance of the helminths parasitising kittiwakes and glaucous gulls in the Barents Sea are proposed. Those are regional climatic features and regional traits in the behaviour and food priorities of birds, and also the distribution of the helminths intermediate hosts, invertebrates and fishes. The phenomenon of host specificity lowering with respect to the definitive host was recorded in some

  11. Recent ice cap snowmelt in Russian High Arctic and anti-correlation with late summer sea ice extent

    NASA Astrophysics Data System (ADS)

    Zhao, Meng; Ramage, Joan; Semmens, Kathryn; Obleitner, Friedrich

    2014-04-01

    Glacier surface melt dynamics throughout Novaya Zemlya (NovZ) and Severnaya Zemlya (SevZ) serve as a good indicator of ice mass ablation and regional climate change in the Russian High Arctic. Here we report trends of surface melt onset date (MOD) and total melt days (TMD) by combining multiple resolution-enhanced active and passive microwave satellite datasets and analyze the TMD correlations with local temperature and regional sea ice extent. The glacier surface snowpack on SevZ melted significantly earlier (-7.3 days/decade) from 1992 to 2012 and significantly longer (7.7 days/decade) from 1995 to 2011. NovZ experienced large interannual variability in MOD, but its annual mean TMD increased. The snowpack melt on NovZ is more sensitive to temperature fluctuations than SevZ in recent decades. After ruling out the regional temperature influence using partial correlation analysis, the TMD on both archipelagoes is statistically anti-correlated with regional late summer sea ice extent, linking land ice snowmelt dynamics to regional sea ice extent variations.

  12. Kara Sea radioactivity assessment.

    PubMed

    Osvath, I; Povinec, P P; Baxter, M S

    1999-09-30

    Investigations following five international expeditions to the Kara Sea have shown that no radiologically significant contamination has occurred outside of the dumping sites in Novaya Zemlya bays. Increased levels of radionuclides in sediment have only been observed in Abrosimov and Stepovoy Bays very close to dumped containers. Evaluations of radionuclide inventories in water and sediment of the open Kara Sea and Novaya Zemlya bays as well as soil from the shore of Abrosimov bay have shown that radionuclide contamination of the open Kara Sea is mainly due to global fallout, with smaller contributions from the Sellafield reprocessing plant, the Chernobyl accident run-off from the Ob and Yenisey rivers and local fallout. Computer modelling results have shown that maximum annual doses of approximately 1 mSv are expected for a hypothetical critical group subsisting on fish caught in the Novaya Zemlya bays whereas populations living on the mainland can be expected to receive doses at least three orders of magnitude lower.

  13. Documenting the biodiversity of the Madrean Archipelago: An analysis of a virtual flora and fauna

    Treesearch

    Nicholas S. Deyo; Thomas R. Van Devender; Alex Smith; Edward. Gilbert

    2013-01-01

    The Madrean Archipelago Biodiversity Assessment (MABA) of Sky Island Alliance is an ambitious project to document the distributions of all species of animals and plants in the Madrean Archipelago, focusing particularly on northeastern Sonora and northwestern Chihuahua, Mexico. The information is made available through MABA’s online database (madrean.org). The sources...

  14. New records of mosquito species for different islands of the Ryukyu Archipelago, Japan.

    PubMed

    Toma, Takako; Miyagi, Ichiro; Tamashiro, Mikako; Higa, Yukiko

    2011-06-01

    During an 11-year study period (1999-2010) on the islands of the Ryukyu Archipelago, Japan, 20 mosquito species were identified. The results revealed new records of species hitherto not reported on these islands. This contribution updates the mosquito fauna of the various islands of the Ryukyu Archipelago.

  15. Commensal Leucothoidae (Crustacea, Amphipoda) of the Ryukyu Archipelago, Japan. Part III: coral rubble-dwellers

    PubMed Central

    White, Kristine N.; Reimer, James Davis

    2012-01-01

    Abstract Commensal leucothoid amphipods have been collected from coral rubble samples throughout the Ryukyu Archipelago, Japan. Seven new species are described in two generawith valuable location data. A new locality is presented for Paranamixis misakiensis Thomas, 1997. An identification key to all described Leucothoidae of the Ryukyu Archipelago is provided. PMID:22448118

  16. Commensal Leucothoidae (Crustacea, Amphipoda) of the Ryukyu Archipelago, Japan. Part I: ascidian-dwellers

    PubMed Central

    White, Kristine N.; Reimer, James Davis

    2012-01-01

    Abstract Commensal leucothoid amphipods have been collected from the branchial chambers of their ascidian hosts throughout the Ryukyu Archipelago, Japan. Seven new species are described in two genera with valuable location data and host records. An identification key to ascidian-dwelling Leucothoidae of the Ryukyu Archipelago is provided. PMID:22303128

  17. Commensal Leucothoidae (Crustacea, Amphipoda) of the Ryukyu Archipelago, Japan. Part II: sponge-dwellers

    PubMed Central

    White, Kristine N.; Reimer, James Davis

    2012-01-01

    Abstract Commensal leucothoid amphipods have been collected from the canals of their sponge hosts throughout the Ryukyu Archipelago, Japan. Eleven new species are described in the genus Leucothoe with valuable location data and host records. An identification key to sponge-dwelling Leucothoidae of the Ryukyu Archipelago is provided. PMID:22328858

  18. 'Redefining health care': medical homes or archipelagos to navigate?

    PubMed

    Enthoven, Alain C; Crosson, Francis J; Shortell, Stephen M

    2007-01-01

    This paper provides an analysis of the structure of the health care delivery system, emphasizing physician group practices. The authors argue for comprehensive integrated delivery systems (IDSs). The jumping-off point for their analysis is the recently published Redefining Health Care: Creating Value-Based Competition on Results, by Michael Porter and Elizabeth Teisberg. The authors focus on the book's core idea that competitors should be freestanding integrated practice units (or "islands in archipelagos") versus IDSs (or "medical homes"). In any case, the authors contend that this issue should be resolved by competition to attract and serve informed, cost-conscious, responsible consumers on a level playing field.

  19. Seasonal and distributional patterns of seabirds along the Aleutian Archipelago

    USGS Publications Warehouse

    Renner, M.; Hunt, G.L.; Piatt, J.F.; Byrd, G.V.

    2008-01-01

    The Aleutian Archipelago is of global importance to seabirds during the northern summer, but little is known about seabird use of these waters during winter. We compare summer and winter abundances of seabirds around 3 islands: Buldir in the western, Kasatochi in the central, and Aiktak in the eastern Aleutians. The density of combined seabird biomass in nearshore marine waters was higher in summer than in winter at Buldir and Kasatochi, but was higher in winter at Aiktak, despite the departure of abundant migratory species. Comparing foraging guilds, we found that only piscivores increased at the western and central sites in winter, whereas at the eastern site several planktivorous species increased as well. The only planktivore remaining in winter at the central and western sites in densities comparable to summer densities was whiskered auklet Aethia pygmaea. Crested auklet Aethia cristatella and thick-billed murre Uria lomvia showed the greatest proportional winter increase at the eastern site. The seasonal patterns of the seabird communities suggest a winter breakdown of the copepod-based food web in the central and western parts of the archipelago, and a system that remains rich in euphausiids in the eastern Aleutians. We suggest that in winter crested auklets take the trophic role that short-tailed shearwaters Puffinus tenuirostris occupy during summer. We hypothesize that advection of euphausiids in the Aleutian North Slope Current is important for supporting the high biomass of planktivores that occupy the Unimak Pass region on a year-round basis. ?? Inter-Research 2008.

  20. Optimizing velocities and transports for complex coastal regions and archipelagos

    NASA Astrophysics Data System (ADS)

    Haley, Patrick J.; Agarwal, Arpit; Lermusiaux, Pierre F. J.

    2015-05-01

    We derive and apply a methodology for the initialization of velocity and transport fields in complex multiply-connected regions with multiscale dynamics. The result is initial fields that are consistent with observations, complex geometry and dynamics, and that can simulate the evolution of ocean processes without large spurious initial transients. A class of constrained weighted least squares optimizations is defined to best fit first-guess velocities while satisfying the complex bathymetry, coastline and divergence strong constraints. A weak constraint towards the minimum inter-island transports that are in accord with the first-guess velocities provides important velocity corrections in complex archipelagos. In the optimization weights, the minimum distance and vertical area between pairs of coasts are computed using a Fast Marching Method. Additional information on velocity and transports are included as strong or weak constraints. We apply our methodology around the Hawaiian islands of Kauai/Niihau, in the Taiwan/Kuroshio region and in the Philippines Archipelago. Comparisons with other common initialization strategies, among hindcasts from these initial conditions (ICs), and with independent in situ observations show that our optimization corrects transports, satisfies boundary conditions and redirects currents. Differences between the hindcasts from these different ICs are found to grow for at least 2-3 weeks. When compared to independent in situ observations, simulations from our optimized ICs are shown to have the smallest errors.

  1. New vascular plant records for the Canadian Arctic Archipelago

    PubMed Central

    Gillespie, Lynn J.; Saarela, Jeffery M.; Sokoloff, Paul C.; Bull, Roger D.

    2015-01-01

    Abstract The Canadian Arctic Archipelago is a vast region of approximately 1,420,000 km2, with a flora characterized by low species diversity, low endemicity, and little influence by alien species. New records of vascular plant species are documented here based on recent fieldwork on Victoria and Baffin Islands; additional records based on recent literature sources are mentioned. This paper serves as an update to the 2007 publication Flora of the Canadian Arctic Archipelago, and brings the total number of vascular plants for the region to 375 species and infraspecific taxa, an increase of 7.7%. Three families (Amaranthaceae, Juncaginaceae, Pteridaceae) and seven genera (Cherleria L., Cryptogramma R. Br., Platanthera Rich., Sabulina Rchb., Suaeda Forssk. ex J.F. Gmel., Triglochin L., Utricularia L.) are added to the flora, and one genus is deleted (Minuartia L.). Five species are first records for Nunavut (Arenaria longipedunculata Hultén, Cryptogramma stelleri (S.G. Gmel.) Prantl, Puccinellia banksiensis Consaul, Saxifraga eschscholtzii Sternb., Utricularia ochroleuca R.W. Hartm.) PMID:26311505

  2. The scale insects (Hemiptera: Coccoidea) of the Maltese Archipelago.

    PubMed

    Mifsud, David; Mazzeo, Gaetana; Russo, Agatino; Watson, Gillian W

    2014-09-25

    Past works on scale insects (Hemiptera: Coccoidea) from the Maltese Archipelago are reviewed. Based on the literature and contemporary collections, a total of 93 species of scale insects belonging to 12 scale insect families are here reported (Aclerdidae 1 species; Asterolecaniidae 4; Coccidae 17; Diaspididae 46; Eriococcidae 5; Kermesidae 1; Margarodidae 1; Micrococcidae 1; Monophlebidae 2; Pseudoccocidae 11; Putoidae 2 and Rhizoecidae 2). Of these, 17 species represent new distribution records. Ten species are excluded from the scale insect fauna of the Maltese Islands. Of the 93 species present, only 29 (31.18%) are probably indigenous and the rest (68.82%) represent established introductions from elsewhere. More than 65% of the indigenous species are typical Mediterranean in distribution, with a few species having a mainly European chorotype. A quarter of the established aliens originate from Eurasia, followed by an East Asian/ Oriental component (20.31%); European (14.06%); Neotropical (14.06%); cryptogenic (14.06%); African (7.81%) and Australasian (4.70%). Movement of live fruit trees and ornamental plants into the Maltese Archipelago from nearby countries is probably the main route for entry of alien scale insects into the country. Some possible future introductions are discussed.

  3. [Vegetation landscape health assessment in Changshan Archipelago, North Yellow Sea].

    PubMed

    Suo, An-ning; Sun, Yong-guang; Li, Bin-yong; Lin, Yong; Zhang, Yong-hua

    2015-04-01

    Island vegetation is an important component of island ecosystem. Multi-targets of island ecosystem health integrated with landscape ecology theory were employed to construct the index system for island vegetation health assessment in terms of landscape vigor, landscape stressing intensity and landscape stability. The Changshan Archipelago in the North Yellow Sea was chosen as a case to apply the island vegetation health assessment index system. The results showed that the overall vegetation health status in Changshan Archipelago was good and had a big island variation. The vegetation health index for Haiyang Island and Zhangzi Island was above 0.80, belonging to first eco-health level area, whereas that for Dachangshan Island, Xiaochangshan Island and Dawangjia Island ranged from 0.70 to 0.80, which could be categorized as the second eco-health level area. Guanglu Island and Shichen Island could be termed as the third eco-health level area with the vegetation health index below 0.70. The distance of island to mainland, area of island together with industrial structure were the main driving forces for the variation of vegetation landscape heath between different islands.

  4. Temporal analysis of remotely sensed turbidity in a coastal archipelago

    NASA Astrophysics Data System (ADS)

    Suominen, Tapio; Tolvanen, Harri

    2016-07-01

    A topographically fragmental archipelago with dynamic waters set the preconditions for assessing coherent remotely sensed information. We generated a turbidity dataset for an archipelago coast in the Baltic Sea from MERIS data (FSG L1b), using CoastColour L1P, L2R and L2W processors. We excluded land and mixed pixels by masking the imagery with accurate (1:10 000) shoreline data. Using temporal linear averaging (TLA), we produced satellite-imagery datasets applicable to temporal composites for the summer seasons of three years. The turbidity assessments and temporally averaged data were compared to in situ observations obtained with coastal monitoring programs. The ability of TLA to estimate missing pixel values was further assessed by cross-validation with the leave-one-out method. The correspondence between L2W turbidity and in situ observations was good (r = 0.89), and even after applying TLA the correspondence remained acceptable (r = 0.78). The datasets revealed spatially divergent temporal water characteristics, which may be relevant to the management, design of monitoring and habitat models. Monitoring observations may be spatially biased if the temporal succession of water properties is not taken into account in coastal areas with anisotropic dispersion of waters and asynchronous annual cycles. Accordingly, areas of varying turbidity may offer a different habitat for aquatic biota than areas of static turbidity, even though they may appear similar if water properties are measured for short annual periods.

  5. New vascular plant records for the Canadian Arctic Archipelago.

    PubMed

    Gillespie, Lynn J; Saarela, Jeffery M; Sokoloff, Paul C; Bull, Roger D

    2015-01-01

    The Canadian Arctic Archipelago is a vast region of approximately 1,420,000 km(2), with a flora characterized by low species diversity, low endemicity, and little influence by alien species. New records of vascular plant species are documented here based on recent fieldwork on Victoria and Baffin Islands; additional records based on recent literature sources are mentioned. This paper serves as an update to the 2007 publication Flora of the Canadian Arctic Archipelago, and brings the total number of vascular plants for the region to 375 species and infraspecific taxa, an increase of 7.7%. Three families (Amaranthaceae, Juncaginaceae, Pteridaceae) and seven genera (Cherleria L., Cryptogramma R. Br., Platanthera Rich., Sabulina Rchb., Suaeda Forssk. ex J.F. Gmel., Triglochin L., Utricularia L.) are added to the flora, and one genus is deleted (Minuartia L.). Five species are first records for Nunavut (Arenarialongipedunculata Hultén, Cryptogrammastelleri (S.G. Gmel.) Prantl, Puccinelliabanksiensis Consaul, Saxifragaeschscholtzii Sternb., Utriculariaochroleuca R.W. Hartm.).

  6. Seismic Hazard Maps for the Maltese Archipelago: Preliminary Results

    NASA Astrophysics Data System (ADS)

    D'Amico, S.; Panzera, F.; Galea, P. M.

    2013-12-01

    The Maltese islands form an archipelago of three major islands lying in the Sicily channel at about 140 km south of Sicily and 300 km north of Libya. So far very few investigations have been carried out on seismicity around the Maltese islands and no maps of seismic hazard for the archipelago are available. Assessing the seismic hazard for the region is currently of prime interest for the near-future development of industrial and touristic facilities as well as for urban expansion. A culture of seismic risk awareness has never really been developed in the country, and the public perception is that the islands are relatively safe, and that any earthquake phenomena are mild and infrequent. However, the Archipelago has been struck by several moderate/large events. Although recent constructions of a certain structural and strategic importance have been built according to high engineering standards, the same probably cannot be said for all residential buildings, many higher than 3 storeys, which have mushroomed rapidly in recent years. Such buildings are mostly of unreinforced masonry, with heavy concrete floor slabs, which are known to be highly vulnerable to even moderate ground shaking. We can surely state that in this context planning and design should be based on available national hazard maps. Unfortunately, these kinds of maps are not available for the Maltese islands. In this paper we attempt to compute a first and preliminary probabilistic seismic hazard assessment of the Maltese islands in terms of Peak Ground Acceleration (PGA) and Spectral Acceleration (SA) at different periods. Seismic hazard has been computed using the Esteva-Cornell (1968) approach which is the most widely utilized probabilistic method. It is a zone-dependent approach: seismotectonic and geological data are used coupled with earthquake catalogues to identify seismogenic zones within which earthquakes occur at certain rates. Therefore the earthquake catalogues can be reduced to the

  7. Lithospheric structure and compensation mechanisms of the Galapagos Archipelago

    NASA Astrophysics Data System (ADS)

    Feighner, Mark A.; Richards, Mark A.

    1994-04-01

    Volcanic islands of the Galapagos Archipelago are the most recent subaerial expression of the Galapagos hotspot. These islands and numerous seamounts are constructed mainly upon a broad volcanic platform that overlies very young (less than 10 m.y.) oceanic lithosphere just south of the active Galapagos Spreading Center. The 91 deg W fracture zone crosses the platform and creates an estimated 5-m.y. age discontinuity in the lithosphere. Major tectonic features of the Galapagos include an unusually broad distribution of volcanic centers, pronounced structural trends such as the NW-SE Wolf-Darwin Lineament (WDL), and a steep escarpment along the western and southern margins of the archipelago. We use shipboard gravity and bathymetry data along with Geosat geoid data to explain the tectonic and structural evolution of the Galapagos region. We model the gravity anomalies using a variety of compensation models, including Airy isostasy, continuous elastic flexure of the lithosphere, and an elastic plate with embedded weaknesses, and we infer significant lithospheric strength variations across the archipelago. The outboard parts of the southern and western escarpment are flexurally supported with an effective elastic thickness of approximately 12 km. This area includes the large shield volcanoes of Fernandina and Isabela Islands, where the lithosphere regionally supports these volcanic loads. The central platform is weaker, with an elastic thickness of 6 km or less, and close to Airy isostasy. The greatest depths to the Moho are located beneath eastern Isabela Island and the central platform. Thinner lithosphere in this region may account for the broad distribution of volcanoes, the extended period of eruption of the central volcanoes, and their reduced size. The transition from strong to weak lithosphere along the southern escarpment appears to be abrupt, within the resolution of our models, and can be best represented by a free end or faultlike discontinuity. Also

  8. Paleomagnetic Study of Azores Archipelago: Volcano-Tectonic Implications

    NASA Astrophysics Data System (ADS)

    Silva, P. F.; Henry, B.; Marques, F. O.; Madureira, P.; Miranda, J. M. A.; Lourenco, N. V.; Madeira, J.; Hildenbrand, A.; Nunes, J. C.; Roxerová, Z.

    2014-12-01

    Oceanic islands are by nature unstable volcanic buildings generally marked by rapid growth that alternates with destruction due to a variety of mass-wasting processes, including giant sector collapses, vertical caldera subsidence, fault generation/propagation, shallow landslides and coastal erosion. Due to its diverse volcanic and tectonic frameworks, the Azores archipelago represents an excellent case study for geophysical and geological proposes. Main results of a paleomagnetic study, conducted on oriented samples from approximately 60 accessible lava piles of three islands of Azores archipelago central group (Faial, Pico and Terceira islands) and covering as much as possible spatially and temporally these islands are: i) The paleomagnetic polarity is in close agreement with the radiometric results known for these islands; ii) Onshore volcanic activity began during the Matuyama geochron for Faial and during Brunhes for Terceira and Pico; iii) The mean ChRMs from Terceira and Pico islands result in a paleomagnetic pole similar to the ones retrieved from the studies of Johnson et al (1998) and Silva et al (2012), from S. Miguel and S. Jorge islands (other islands of Azores archipelago), respectively; iv) ChRMs from Faial show an elliptical distribution perpendicular to the WNW-ESE grabben that is the major structure of the island, suggesting tilting towards SSW of the southern wall and towards NNE of the northern one. The presence of listric faults plunging towards the middle of the grabben and aligned along the N110º azimuth could explain the elliptical distribution of paleomagnetic directions. This study is a contribution for the research project REGENA (PTDC/GEO-FIQ/3648/2012). References Johnson, C.L., Wijbrans, J.R., Constable, C.G., Gee, J., Staudigel, H., Tauxe, L., Forjaz, V.-H., Salgueiro, M., 1998. 40Ar/39Ar ages and paleomagnetism of S. Miguel lavas,Azores, Earth planet. Sci. Lett., 160, 637-649. Silva, PF; Henry, B; Marques, FO; Hildenbrand, A

  9. Neoproterozoic Stromatolites and Microphytolites of the Spitsbergen Archipelago

    NASA Astrophysics Data System (ADS)

    Anisimov, Artem; Anisimova, Svetlana; Kosteva, Natalia

    2017-04-01

    The Svalbard archipelago is located in the extreme North-West of the Barents Sea. On the archipelago in the framework of large-scale exploration of the continental shelf exploration work carried out by employees of the Polar Marine Geological Expedition (PMGE). The authors were further explored and tested the Neoproterozoic sections of the Groups Veteranen, Akademikarbreen and Polarisbreen on the East and West banks of the Sorgfjorden (the Northern part of the Ny Friesland Peninsula) and in the moraine of the glacier Duner. The rocks carbonate-terrigenous Veteranen Group (upper Riphean) is set in the rocky outcrops on the Western and Eastern banks of Sorgfjorden and in ice-dressed rocks of the Bay. The Group consists of four Formations (bottom to top): Kortbreen, Kingbreen, Glasgowbreen and Oxfordbreen. The rocks carbonate-terrigenous Akademikarbreen Group (upper Riphean) have a lower areal distribution than the breed Veteranen Group in the project area is established only in the southern part of the Bay, in the valleys Kluftdalen, Rivnedalen and small-unnamed streams, as well as on the plateau Fleinfjellet and Vidarfjellet. The Groups consists of four formation (bottom to top): Grusdievbreen, Svanbergfjellet, Draken and Backlundtoppen. According to previous researchers, limestone in Kingbreen Formation (Veteranen Group) met with radial-rayed Microphytolites group Radiosus. And in light grey, cream, pink and red limestones of the Academikarbreen Group, in the Svanbergfjellet Formation defined columnar branching Stromatolites Inzeria djejimi Raab., Gymnosolen aff. ramsayi Steinm. Stromatolites of Conophyton miloradovichi Raab. in the dolomites of the overlying sediments Draken and Backlundtoppen Formations contain Vendian the bubbles Microphytolites Vesicularites bothrydioformis Krasnop. In carbonate rocks of the Akademikerbreen Group were confirmed by the finds of Neoproterozoic microbial entities identified by previous researchers, and identified new locations of

  10. Nematodes from terrestrial and freshwater habitats in the Arctic

    PubMed Central

    2014-01-01

    Abstract We present an updated list of terrestrial and freshwater nematodes from all regions of the Arctic, for which records of properly identified nematode species are available: Svalbard, Jan Mayen, Iceland, Greenland, Nunavut, Northwest territories, Alaska, Lena River estuary, Taymyr and Severnaya Zemlya and Novaya Zemlya. The list includes 391 species belonging to 146 genera, 54 families and 10 orders of the phylum Nematoda. PMID:25197239

  11. Dispersal has inhibited avian diversification in Australasian archipelagoes.

    PubMed

    Weeks, Brian C; Claramunt, Santiago

    2014-09-22

    Different models of speciation predict contrasting patterns in the relationship between the dispersal ability of lineages and their diversification rates. This relationship is expected to be negative in isolation-limited models and positive in founder-event models. In addition, the combination of negative and positive effects of dispersal on speciation can result in higher diversification rates at intermediate levels of dispersal ability. Using molecular phylogenies to estimate diversification rates, and wing morphology to estimate dispersal ability, we analysed the influence of dispersal on diversification in the avifauna of Australasian archipelagoes. Contrary to expectations given the fragmented nature of island systems, the relationship between dispersal ability and diversification rate was monotonically negative. While multiple mechanisms could generate this pattern, they all share a phase of range expansion that is decoupled from speciation. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  12. Satellite communication subsystem design for the Indonesian Archipelago

    NASA Astrophysics Data System (ADS)

    Gaspari, R. A.; Neuman, M. E.; Asturi, H.

    To meet the requirements of the Indonesian Archipelago, an advanced communication subsystem was designed which incorporated many key system advances. Orthogonally polarized grid reflectors, offset feed with displaced foci, provide shaped beam coverage of orthogonal polarizations with maximum reflector area for each. The 24 channels of 36 MHz each are implemented by functionally separate horizontal and vertical repeaters. High efficiency traveling wave tubes with triply depressed collectors provide downlink power amplification, while a 5 for 4 redundancy implementation insures reliability. Channel selectivity is established by elliptic function input and output multiplexers utilizing circulator dropping techniques on the input and common manifold combining on the output. As a result of this system implementation, it has been possible to achieve 34 dBW downlink EIRP and -5 dB K uplink G/T with a much smaller spacecraft than previously achieved.

  13. Inversion of Seabed Parameters in the Stockholm Archipelago

    NASA Astrophysics Data System (ADS)

    Abrahamsson, L.; Andersson, B. L.

    2001-12-01

    The purpose of this work was to apply acoustic inversion to a bay in the Stockholm archipelago with strong variations of the bottom both vertically and horizontally. The inversions were based on measurements undertaken in May 2001 of transmission loss over a 2.5 km long track. The bottom parameters were estimated by minimizing the difference between simulated and measured data. The parabolic wave equation was used as a wave propagation model and the inversions were carried out by a genetic algorithm. They resulted in a relatively good fit. The inverted bottom parameters were also evaluated by model predictions against a control data set of other frequencies than those of the inversion. The agreement between the estimated and measured parameters was good.

  14. Dispersal has inhibited avian diversification in Australasian archipelagoes

    PubMed Central

    Weeks, Brian C.; Claramunt, Santiago

    2014-01-01

    Different models of speciation predict contrasting patterns in the relationship between the dispersal ability of lineages and their diversification rates. This relationship is expected to be negative in isolation-limited models and positive in founder-event models. In addition, the combination of negative and positive effects of dispersal on speciation can result in higher diversification rates at intermediate levels of dispersal ability. Using molecular phylogenies to estimate diversification rates, and wing morphology to estimate dispersal ability, we analysed the influence of dispersal on diversification in the avifauna of Australasian archipelagoes. Contrary to expectations given the fragmented nature of island systems, the relationship between dispersal ability and diversification rate was monotonically negative. While multiple mechanisms could generate this pattern, they all share a phase of range expansion that is decoupled from speciation. PMID:25100701

  15. Elevation changes of ice caps in the Canadian Arctic Archipelago

    NASA Astrophysics Data System (ADS)

    Abdalati, W.; Krabill, W.; Frederick, E.; Manizade, S.; Martin, C.; Sonntag, J.; Swift, R.; Thomas, R.; Yungel, J.; Koerner, R.

    2004-12-01

    Precise repeat airborne laser surveys were conducted over the major ice caps in the Canadian Arctic Archipelago in the spring of 1995 and 2000 in order to measure elevation changes in the region. Our measurements reveal thinning at lower elevations (below 1600 m) on most of the ice caps and glaciers but either very little change or thickening at higher elevations in the ice cap accumulation zones. Recent increases in precipitation in the area can account for the slight thickening where it was observed but not for the thinning at lower elevations. For the northern ice caps on the Queen Elizabeth Islands, thinning was generally <0.5 m yr-1, which is consistent with what would be expected from the warm temperature anomalies in the region for the 5 year period between surveys, and appears to be a continuation of a trend that began in the mid-1980s. Farther south, however, on the Barnes and Penny ice caps on Baffin Island, this thinning was much more pronounced at over 1 m yr-1 in the lower elevations. Here temperature anomalies were very small, and the thinning at low elevations far exceeds any associated enhanced ablation. The observations on Barnes, and perhaps Penny, are consistent with the idea that the observed thinning is part of a much longer term deglaciation, as has been previously suggested for Barnes ice cap. On the basis of the regional relationships between elevation and elevation change in our data, the 1995-2000 mass balance for the archipelago is estimated to be -25 km3 yr-1 of ice, which corresponds to a sea level increase of 0.064 mm yr-1. This places it among the more significant sources of eustatic sea level rise, though not as substantial as the Greenland ice sheet, Alaskan glaciers, or the Patagonian ice fields.

  16. Environmental contaminants in bald eagle eggs from the Aleutian archipelago.

    PubMed

    Anthony, Robert G; Miles, A Keith; Ricca, Mark A; Estes, James A

    2007-09-01

    We collected 136 fresh and unhatched eggs from bald eagle (Haliaeetus leucocephalus) nests and assessed productivity on eight islands in the Aleutian archipelago, 2000 to 2002. Egg contents were analyzed for a broad spectrum of organochlorine (OC) contaminants, mercury (Hg), and stable isotopes of carbon (delta13C) and nitrogen (delta15N). Concentrations of polychlorinated biphenyls (SigmaPCBs), p,p'-dichlorodiphenyldichloroethylene (DDE), and Hg in bald eagle eggs were elevated throughout the archipelago, but the patterns of distribution differed among the various contaminants. Total PCBs were highest in areas of past military activities on Adak and Amchitka Islands, indicating local point sources of these compounds. Concentrations of DDE and Hg were higher on Amchitka Island, which was subjected to much military activity during World War II and the middle of the 20th century. Concentrations of SigmaPCBs also were elevated on islands with little history of military activity (e.g., Amlia, Tanaga, Buldir), suggesting non-point sources of PCBs in addition to point sources. Concentrations of DDE and Hg were highest in eagle eggs from the most western Aleutian Islands (e.g., Buldir, Kiska) and decreased eastward along the Aleutian chain. This east-to-west increase suggested a Eurasian source of contamination, possibly through global transport and atmospheric distillation and/or from migratory seabirds. Eggshell thickness and productivity of bald eagles were normal and indicative of healthy populations because concentrations of most contaminants were below threshold levels for effects on reproduction. Contrary to our predictions, contaminant concentrations were not correlated with stable isotopes of carbon (delta13C) or nitrogen (delta15N) in eggs. These latter findings indicate that contaminant concentrations were influenced more by point sources and geographic location than trophic status of eagles among the different islands.

  17. Environmental contaminants in bald eagle eggs from the Aleutian archipelago

    USGS Publications Warehouse

    Anthony, R.G.; Miles, A.K.; Ricca, M.A.; Estes, J.A.

    2007-01-01

    We collected 136 fresh and unhatched eggs from bald eagle (Haliaeetus leucocephalus) nests and assessed productivity on eight islands in the Aleutian archipelago, 2000 to 2002. Egg contents were analyzed for a broad spectrum of organochlorine (OC) contaminants, mercury (Hg), and stable isotopes of carbon (??13C) and nitrogen (??15N). Concentrations of polychlorinated biphenyls (??PCBs), p,p???- dichlorodiphenyldichloroethylene (DDE), and Hg in bald eagle eggs were elevated throughout the archipelago, but the patterns of distribution differed among the various contaminants. Total PCBs were highest in areas of past military activities on Adak and Amchitka Islands, indicating local point sources of these compounds. Concentrations of DDE and Hg were higher on Amchitka Island, which was subjected to much military activity during World War II and the middle of the 20th century. Concentrations of ??PCBs also were elevated on islands with little history of military activity (e.g., Amlia, Tanaga, Buldir), suggesting non-point sources of PCBs in addition to point sources. Concentrations of DDE and Hg were highest in eagle eggs from the most western Aleutian Islands (e.g., Buldir, Kiska) and decreased eastward along the Aleutian chain. This east-to-west increase suggested a Eurasian source of contamination, possibly through global transport and atmospheric distillation and/or from migratory seabirds. Eggshell thickness and productivity of bald eagles were normal and indicative of healthy populations because concentrations of most contaminants were below threshold levels for effects on reproduction. Contrary to our predictions, contaminant concentrations were not correlated with stable isotopes of carbon (??13C) or nitrogen (??15N) in eggs. These latter findings indicate that contaminant concentrations were influenced more by point sources and geographic location than trophic status of eagles among the different islands. ?? 2007 SETAC.

  18. Genetic characterization of brown bears of the Kodiak Archipelago

    USGS Publications Warehouse

    Talbot, Sandra L.; Gust, Judy R.; Sage, George K.; Fischbach, Anthony S.; Amstrup, Kristin S.; Leacock, William; Van Daele, Larry

    2006-01-01

    Here we examine genetic characteristics of brown bears of Kodiak and Afognak islands, using 14 variable nuclear microsatellite loci and nucleotide sequence information including the hypervariable domain I of the mtDNA control region (Wakely 1993). Because these markers, or a subset of them, have been used to characterize brown bears of the Kenai Peninsula (Jackson et al. 2005), Katmai National Park, Seward Peninsula, and nine other populations in Alaska (Talbot, unpublished data), we compared levels of genetic diversity and relationships among populations when possible. In addition, we obtained preliminary comparative information from class II DQA and DQB genes of the brown bear MHC, to examine levels of variation at this important immunology-mediating supergene. These data were used to answer the following questions: 1) are earlier findings of extremely low levels of variability at nuclear (biparentallyinherited) microsatellite loci from a small geographic area (Paetkau et al. 1998b) representative of Kodiak Archipelago populations as a whole? 2) Is the level and type of variation at the maternally-inherited mtDNA lower, or similar to, levels found in other populations in Alaska? 3) Is there concordance between low levels of genetic variation observed at neutral markers with levels of variation observed at functional genes? 4) Is there population substructuring within Kodiak and Afognak islands? 5) What is the connectivity between populations on Afognak Island and Kodiak Island? 6) What are the phylogeographic relationships between bears of the Kodiak Archipelago with brown bears on mainland Alaskan and other western Beringian populations? We also test whether these markers will provide an appropriate baseline for designing genetic tagging studies for use in future research and management activities, such as mark-recapture efforts, on the Refuge.

  19. Detailed temperature mapping-Warming characterizes archipelago zones

    NASA Astrophysics Data System (ADS)

    Veneranta, L.; Vanhatalo, J.; Urho, L.

    2016-12-01

    Rapidly warming shallow archipelago areas have the best energetic options for high ecological production. We analyzed and visualized the spring and summer temperature development in the Finnish coastal areas of the Northern Baltic Sea. Typical for the Baltic is a high annual periodicity and variability in water temperatures. The maximum difference between a single day average temperatures across the study area was 28.3 °C. During wintertime the littoral water temperature can decrease below zero in outer archipelago or open water areas when the protective ice cover is not present and the lowest observed value was -0.5 °C. The depth and exposition are the most important variables explaining the coastal temperature gradients from the innermost to the outermost areas in springtime when water is heated by increasing solar radiation. Temperature differs more within coastal area than between the basins. Water temperature sum was highest in innermost areas, lowest in open water areas and the variation in daily averages was highest in the middle region. At the end of the warming period, the difference in surface water temperatures between the innermost and outermost areas had diminished at the time when the cooling began in August-September. These clear temperature gradients enabled us use the cumulative water temperature to classify the coastal zones in a biologically sensible manner into five regions. Our study shows a novel approach to study detailed spatial variations in water temperatures. The results can further be used, for example, to model and predict the spatial distribution of aquatic biota and to determine appropriate spatio-temporal designs for aquatic biota surveys. The new spatial knowledge of temperature regions will also help the evaluation of possible causes of larger scale climatological changes in a biological context including productivity.

  20. Shelf Exchange Processes of CO2, Ra, and Ba in the Canadian Arctic Archipelago

    NASA Astrophysics Data System (ADS)

    Thomas, Helmuth; Dehairs, Frank; Mol, Jacoba

    2017-04-01

    The Canadian Arctic Archipelago has been sampled during the Canadian GEOTRACES program in summer 2015. In Baffin Bay and Archipelagic waters dissolved inorganic carbon (DIC), alkalinity (AT), and barium (Ba) measurements have been performed, which were paralleled at selected stations by measurements of the two short-lived radium isotopes 223Ra and 224Ra. Using these observations we investigate relevant transport processes within the Canadian Arctic Archipelago: lateral and vertical diffusion from the sediments, river runoff, transport of water masses through the Archipelago and inflow of water masses of Atlantic and Pacific origin, respectively into the Archipelago. The impact of theses processes on the biogeochemistry, and in particular ocean acidification will be assessed.

  1. The Galapagos archipelago: A natural laboratory to examine sharp hydroclimatic, geologic and anthropogenic gradients

    USGS Publications Warehouse

    Percy, Madelyn; Schmitt, Sarah; Riveros-Iregui, Diego; Mirus, Benjamin B.

    2016-01-01

    Poor understanding of the water cycle in tropical ecosystems has the potential to exacerbate water shortages and water crises in the region. We suggest that the Galápagos Islands provide an excellent proxy to regions across the tropics as a result of sharp hydroclimatic, anthropogenic, and pedohydrologic gradients across the archipelago. Hydroclimatic and pedohydrologic gradients are found across different elevations on single islands, as well as across the archipelago, whereas anthropogenic gradients reflect land use and land cover change across islands as population and growth in tourism have affected individual islands differently. This article highlights specific opportunities to further examine our understanding of the interactions between water and critical zone processes in tropical ecosystems, making connections between the Galápagos archipelago and much of the understudied tropics. The Galápagos archipelago offers a natural laboratory through which we can examine current threats to freshwater security as well as the dynamics of coupled natural and human systems.

  2. Polycyclic aromatic hydrocarbons in mussel and fish from the Finnish Archipelago Sea

    SciTech Connect

    Not Available

    1986-09-01

    Marine organisms are known to adsorb and accumulate PAH's from water. Mussels due to their widespread distribution in coastal waters have been studied in many laboratory and field experiments for their responses to PAH exposures. The occurrence of PAH's has been studied also in fish. This report presents preliminary data for the PAH content in blue mussel and fish from the Finnish Archipelago Sea. Mussel and fish samples were collected from the Finnish Archipelago Sea during 1978-1979.

  3. Cause and risk of catastrophic eruptions in the Japanese Archipelago

    PubMed Central

    TATSUMI, Yoshiyuki; SUZUKI-KAMATA, Keiko

    2014-01-01

    The Japanese Archipelago is characterized by active volcanism with variable eruption styles. The magnitude (M)-frequency relationships of catastrophic caldera-forming eruptions (M ≥ 7) are statistically different from those of smaller eruptions (M ≤ 5.7), suggesting that different mechanisms control these eruptions. We also find that volcanoes prone to catastrophic eruptions are located in regions of low crustal strain rate (<0.5 × 108/y) and propose, as one possible mechanism, that the viscous silicic melts that cause such eruptions can be readily segregated from the partially molten lower crust and form a large magma reservoir in such a tectonic regime. Finally we show that there is a ∼1% probability of a catastrophic eruption in the next 100 years based on the eruption records for the last 120 ky. More than 110 million people live in an area at risk of being covered by tephra >20 cm thick, which would severely disrupt every day life, from such an eruption on Kyushu Island, SW Japan. PMID:25391319

  4. Assessment of Satellite Precipitation Products in the Philippine Archipelago

    NASA Astrophysics Data System (ADS)

    Ramos, M. D.; Tendencia, E.; Espana, K.; Sabido, J.; Bagtasa, G.

    2016-06-01

    Precipitation is the most important weather parameter in the Philippines. Made up of more than 7100 islands, the Philippine archipelago is an agricultural country that depends on rain-fed crops. Located in the western rim of the North West Pacific Ocean, this tropical island country is very vulnerable to tropical cyclones that lead to severe flooding events. Recently, satellite-based precipitation estimates have improved significantly and can serve as alternatives to ground-based observations. These data can be used to fill data gaps not only for climatic studies, but can also be utilized for disaster risk reduction and management activities. This study characterized the statistical errors of daily precipitation from four satellite-based rainfall products from (1) the Tropical Rainfall Measuring Mission (TRMM), (2) the CPC Morphing technique (CMORPH) of NOAA and (3) the Global Satellite Mapping of Precipitation (GSMAP) and (4) Precipitation Estimation from Remotely Sensed information using Artificial Neural Networks (PERSIANN). Precipitation data were compared to 52 synoptic weather stations located all over the Philippines. Results show GSMAP to have over all lower bias and CMORPH with lowest Mean Absolute Error (MAE) and Root Mean Square Error (RMSE). In addition, a dichotomous rainfall test reveals GSMAP and CMORPH have low Proportion Correct (PC) for convective and stratiform rainclouds, respectively. TRMM consistently showed high PC for almost all raincloud types. Moreover, all four satellite precipitation showed high Correct Negatives (CN) values for the north-western part of the country during the North-East monsoon and spring monsoonal transition periods.

  5. The coastal fishes and fisheries of the Socotra Archipelago, Yemen.

    PubMed

    Zajonz, Uwe; Lavergne, Edouard; Klaus, Rebecca; Krupp, Friedhelm; Aideed, Moteah Sheikh; Saeed, Fouad Naseeb

    2016-04-30

    The Socotra Archipelago is situated in the Gulf of Aden where tropical and "pseudo-temperate" conditions combine to create a unique marine ecosystem. The diversity, ecology, productivity and fisheries of the coastal fish assemblages are still relatively understudied and no update of the scientific knowledge existed. The islands support unique coastal and coral-associated fish assemblages in spite of the limited biogenic reef frameworks. Fish diversity is the highest among comparable Arabian eco-regions, and fish biomass productivity high too by Indian Ocean standards. The production of the once traditionally-managed small-scale fishery is severely declining and whether it is sustainable nowadays is extremely doubtful. At a time when Yemen is torn apart by a severe political and humanitarian crisis it is timely to review and update the current state of knowledge for scientists and managers, and thereby ease access to existing information, facilitating follow-on studies and evidence-based conservation and fisheries management. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Historical ecology of the Raja Ampat Archipelago, Papua Province, Indonesia.

    PubMed

    Palomares, Maria Lourdes D; Heymans, Johanna J; Pauly, Daniel

    2007-01-01

    This work presents a review of the status of marine resources of the Raja Ampat Archipelago, Papua Province, Indonesia, based on narratives of early European expeditions in various museums and libraries in Europe, Canada, and local archives in Papua. More than 500 pertinent documents on the study area were identified and located in various European museums and at the University of British Columbia library. About half of these were scanned (25,000 pages), which yielded the equivalent of 900 pages of text (or 4% of the total number of pages scanned) with observations on abundance and impact of the human population on the marine ecosystem within 2 degrees North and 2 degrees South between 127 degrees and 132 degrees East. In general, these observations, which spanned the period from 1810 to the present, suggest a decrease in the perceived occurrences of turtles, fish, and invertebrates; perceived abundance of turtles, fish, and algae; percieved subsistence exploitation of marine resources; and an increase in perceived commercial exploitation of marine resources. We conclude with a discussion of the problems and potential of contents analysis, and its use in the historical reconstruction of broad biodiversity trends.

  7. A finite volume model simulation for the Broughton Archipelago, Canada

    NASA Astrophysics Data System (ADS)

    Foreman, M. G. G.; Czajko, P.; Stucchi, D. J.; Guo, M.

    A finite volume circulation model is applied to the Broughton Archipelago region of British Columbia, Canada and used to simulate the three-dimensional velocity, temperature, and salinity fields that are required by a companion model for sea lice behaviour, development, and transport. The absence of a high resolution atmospheric model necessitated the installation of nine weather stations throughout the region and the development of a simple data assimilation technique that accounts for topographic steering in interpolating/extrapolating the measured winds to the entire model domain. The circulation model is run for the period of March 13-April 3, 2008 and correlation coefficients between observed and model currents, comparisons between model and observed tidal harmonics, and root mean square differences between observed and model temperatures and salinities all showed generally good agreement. The importance of wind forcing in the near-surface circulation, differences between this simulation and one computed with another model, the effects of bathymetric smoothing on channel velocities, further improvements necessary for this model to accurately simulate conditions in May and June, and the implication of near-surface current patterns at a critical location in the 'migration corridor' of wild juvenile salmon, are also discussed.

  8. Air-sea coupling in the Hawaiian Archipelago

    NASA Astrophysics Data System (ADS)

    Souza, J. M.; Powell, B.; Mattheus, D.

    2014-12-01

    A coupled numerical model is used to investigate the ocean-atmosphere interaction in the lee of the Hawaiian archipelago. The wind curl generated by the island blocking of the trade winds is known to give rise to ocean eddies; however, the impact of the sea surface temperature (SST) and velocity fronts associated with these eddies on the atmosphere is less understood. The main coupling mechanisms are: (i) changes in the near-surface stability and surface stress, (ii) vertical transfer of momentum from higher atmospheric levels to the ocean surface due to an increase of the turbulence in the boundary layer, (iii) secondary circulations associated with perturbations in the surface atmospheric pressure over the SST fronts, and (iv) the impact of the oceanic eddy currents on the net momentum transferred between the atmosphere and the ocean. To assess the relative contribution from each process, a coupled simulation between the Regional Ocean Modeling System (ROMS) and the Weather Research and Forecasting (WRF) models is conducted for the main Hawaiian Islands. The impact of the coupling, the perturbation of the mean wind pattern, and the different spatial scales involved in the air-sea exchanges of momentum and heat are explored.

  9. Early Carboniferous (Visean) lacustrine oil shale in Canadian Arctic archipelago

    SciTech Connect

    Davies, G.R.; Nassichuk, W.W.

    1988-01-01

    The Lower Carboniferous (Visean) Emma Fiord Formation in the Canadian Arctic Archipelago is an oil shale of lacustrine origin composed of black carbonaceous shale, siltstone, and marlstone with interbedded sandstone, conglomerate, and oolitic and algal limestones. At Kleybolte Peninsula on Ellesmere Island, the Emma Fiord Formation was deposited on the tectonically active northwestern rim of the Sverdrup basin; it is now thermally overmature and well beyond the dry gas zone of organic maturation (vitrinite reflectance approx. = 5.0). In contrast, the Emma Fiord sequence on Grinnell Peninsula, Devon Island, near the southern edge of the Sverdrup basin, is immature to marginally mature (vitrinite reflectance = 0.26-0.44) and is composed predominantly of liptinite-rich oil shale. These kerogen-rich rocks contain a high volume of microcrystalline calcite and compositionally are marlstones. The Emma Fiord oil shales were deposited in lakes formed immediately prior to or possibly synchronous with the initiation of rifting in the Sverdrup basin. Syntectonic red-bed conglomerates derived from uplifted horst blocks directly overlie the Emma Fiord rocks. A few beds of conglomerate and sandstone in the upper part of the Emma Fiord Formation possibly record the onset of faulting. The formation closely resembles contemporaneous sequences in northern Alaska, Yukon Territory, Greenland, and Spitsbergen. Clearly, similar tectonic and paleoclimatic factors influenced sedimentation over this area in the Early Carboniferous, with the Sverdrup basin locations lying within 10/sup 0/-15/sup 0/ of the paleoequator. 11 figures, 2 tables.

  10. Alien mink predation induces prolonged declines in archipelago amphibians

    PubMed Central

    Ahola, Markus; Nordström, Mikael; Banks, Peter B; Laanetu, Nikolai; Korpimäki, Erkki

    2006-01-01

    Amphibians are undergoing enigmatic global declines variously attributed to a complex web of anthropogenic forces. Alien predators pose a fundamental threat to biodiversity generally that is predicted to be most acute in island ecosystems. While amphibian eggs and tadpoles are vulnerable to aquatic predators, the effect of predators on adult, reproducing frogs, which most influence amphibian population processes, is unknown. Here, we report on the responses of amphibian populations in the outer Finnish Archipelago to a long-term, large-scale removal of American mink (Mustela vison Schreb.), an invasive predator linked to recent biodiversity loss across Europe. Removal increased both the densities and distribution of common frogs (Rana temporaria L.) but not those of common toads (Bufo bufo L.), which appear to escape mink predation because of their unpalatable skin. Importantly, the largest benefits of mink removal to frog recovery were slow to appear as frogs apparently have a delayed maturation in these harsh environments, which means we must be cautious about reliance upon short-term results. PMID:16720400

  11. Geology, petrography, and petrology of Pinzon Island, galapagos archipelago

    NASA Astrophysics Data System (ADS)

    Baitis, Hartmut W.; Lindstrom, Marilyn M.

    1980-06-01

    Three stratigraphic units based on geologic relationships and paleomagnetic observations may be distinguished on Pinzon Island. The oldest unit is a broad shield which forms the main body of the island and was erupted during a period of reversed magnetic polarity from an area now occupied by a caldera. Subsequent activity was centered about 1.5 km to the north-northwest from vents later engulfed by the collapse of a younger caldera. The lower portion of this sequence was erupted during a period of transitional pole positions and is overlain by flows of normal polarity. Pinzon has the most diverse suite of differentiated tholeiitic rocks found in the Galapagos Archipelago. Products of eruptive cycles are preserved as sequences of tuffs and flows that have decreasing degrees of differentiation and increasing phenocryst abundance upsection. The sequences may be a consequence of tapping successively deeper levels of compositionally zoned magma chambers. Such a model is consistent with computer calculations utilizing major and trace element data for Pinzon rocks, which suggest that lavas of the island may be related by shallow-level crystal fractionation of observed phenocryst minerals.

  12. Two new stingrays (Chondrichthyes: Dasyatidae) from the eastern Indonesian Archipelago.

    PubMed

    Last, Peter R; White, William T

    2013-01-01

    Two new stingrays, Dasyatis longicauda sp. nov. and Himanturajavaensis sp. nov., are described from material collected in the eastern Indonesian Archipelago. These species, which are both relatively small stingrays (both probably smaller than 40 cm DW), have been confused with closest relatives in the region. Dasyatis longicauda sp. nov., known from West Papua, differs from its congener, the Australian endemic D. fluviorum, in having a slightly lower vertebral count, lower pectoral-radial count, a longer tail, larger and less numerous thorns along the mid-disc and tail, as well as a different CO1 Barcode. Himantura javaensis sp. nov., known only from southern Java (near Cilacap), belongs to a complex of small whiprays which also includes another Indonesian species, H. walga. Apart from major differences in squamation and a different CO1 Barcode, Himantura javaensis is more brownish in coloration, has more vertebrae, a longer tail, smaller eye and orbit, more posteriorly positioned sting, shorter adult claspers, shorter pelvic fin, and differs in various measurements around the head.

  13. Acoustic habitat of an oceanic archipelago in the Southwestern Atlantic

    NASA Astrophysics Data System (ADS)

    Bittencourt, Lis; Barbosa, Mariana; Secchi, Eduardo; Lailson-Brito, José; Azevedo, Alexandre

    2016-09-01

    Underwater soundscapes can be highly variable, and in natural conditions are often dominated by biological signals and physical features of the environment. Few studies, however, focused on oceanic islands soundscapes. Islands in the middle of ocean basins can provide a good example of how untouched marine soundscapes are. Autonomous acoustic recordings were carried out in two different seasons in Trindade-Martin Vaz Archipelago, Southwestern Atlantic, providing nearly continuous data for both periods. Sound levels varied daily and between seasons. During summer, higher frequencies were noisier than lower frequencies, with snapping shrimp being the dominating sound source. During winter, lower frequencies were noisier than higher frequencies due to humpback whale constant singing. Biological signal detection had a marked temporal pattern, playing an important role in the soundscape. Over 1000 humpback whale sounds were detected hourly during winter. Fish vocalizations were detected mostly during night time during both summer and winter. The results show an acoustic habitat dominated by biological sound sources and highlight the importance of the island to humpback whales in winter.

  14. Vegetation and Climate history of Franz Jozef Land Archipelago in the Late Holocene according pollen data

    NASA Astrophysics Data System (ADS)

    Nosevich, Ekaterina; Anisimov, Michail; Sapelko, Tatyana

    2015-04-01

    The archipelago Franz-Josef Land is situated in the Arctic Ocean (80°40' N, 54°50'E). It is one of the important areas for arctic research due to organization of Russian Arctic National Park there. Therefore, an interest to the environmental history of this territory grows up and any new data might have a high value. However, geographical remoteness of the archipelago is the reason why there are not much work has been done up to date. .A focus of our researches is vegetation and climate reconstruction during the Late Holocene history according pollen data. In frame of studying of the Franz Josef Land during complex expedition of Russian Arctic National Park on the islands geomorphological and botanical researches was occurred. Nowadays the typical island of archipelago presents the ice cap and glacier-free marine terraces of 35 m high at maximum, where solifluction and permafrost are developed. The archipelago has a maritime Arctic climate. Vegetation of archipelago Franz-Josef Land presents the northern type of Polar Desert. It includes 57 species of vascular plants (Poaceae, Juncaceae, Caryophyllaceae, Brassicaceae, Saxifragaceae etc). We studied the peat core from the southern part of Majbel Island, in the archipelago Franz Josef Land. More than a half of the island is covered by glacier. The core was sampled at the inner margin of ice-free high marine terrace, near the southern slope of bedrock hill. We received preliminary pollen data and radiocarbon data 3010±80 C14 y.a. at the bottom. The pollen concentration is low, but we manage to make some reconstructions of vegetation and climate. For correct interpretation of our results, we used surface samples from different islands of archipelago (Jackson, Hooker, Greely, Alexsandra land, Yeva-Liv, Appolonov, Georg land, Kane, Bell). Subrecent spectra include species presented in flora of region, but also those which are not founded at this region in this time.

  15. Comparative phylogeography of oceanic archipelagos: Hotspots for inferences of evolutionary process

    PubMed Central

    Shaw, Kerry L.; Gillespie, Rosemary G.

    2016-01-01

    Remote island archipelagos offer superb opportunities to study the evolution of community assembly because of their relatively young and simple communities where speciation contributes to the origin and evolution of community structure. There is great potential for common phylogeographic patterns among remote archipelagos that originate through hotspot volcanism, particularly when the islands formed are spatially isolated and linearly arranged. The progression rule is characterized by a phylogeographic concordance between island age and lineage age in a species radiation. Progression is most likely to arise when a species radiation begins on an older island before the emergence of younger islands of a hotspot archipelago. In the simplest form of progression, colonization of younger islands as they emerge and offer appropriate habitat, is coincident with cladogenesis. In this paper, we review recent discoveries of the progression rule on seven hotspot archipelagos. We then discuss advantages that progression offers to the study of community assembly, and insights that community dynamics may offer toward understanding the evolution of progression. We describe results from two compelling cases of progression where the mosaic genome may offer insights into contrasting demographic histories that shed light on mechanisms of speciation and progression on remote archipelagos. PMID:27432948

  16. JPRS Report, Arms Control.

    DTIC Science & Technology

    2007-11-02

    Pavlov evidently does not think of the return that "defense" may generate in five years, as his task is to rob the enterprises now to somehow bring... Ivan Bentsa, followed by report from USSR Defense Ministry by Viktor Litovkin: "Novaya Zemlya Prepares For Nuclear Explosions"] [Text] New plans for

  17. Chapter 19: Geology and petroleum potential of the east Barents Sea Basins and Admiralty Arch

    USGS Publications Warehouse

    Klett, T.R.; Pitman, J.K.

    2011-01-01

    The US Geological Survey (USGS) recently assessed the potential for undiscovered oil and gas resources of the East Barents Basins and Novaya Zemlya Basins and Admiralty Arch Provinces as part of the USGS Circum-Arctic Resource Appraisal. These two provinces are located NE of Scandinavia and the northwestern Russian Federation, on the Barents Sea Shelf between Novaya Zemlya to the east and the Barents Platform to the west. Three assessment units (AUs) were defined in the East Barents Basins for this study - Kolguyev Terrace Assessment Unit (AU), South Barents Basin and Ludlov Saddle AU, and North Barents Basin AU. A fourth, defined as Novaya Zemlya Basins and Admiralty Arch AU, is coincident with the Novaya Zemlya basins and Admiralty Arch Province. These AUs, all lying north of the Arctic Circle, were assessed for undiscovered, technically recoverable resources resulting in total estimated mean volumes of approximately 7.4 billion barrels of crude oil, 318 trillion cubic feet of natural gas and 1.4 billion barrels of natural gas liquids. ?? 2011 The Geological Society of London.

  18. Strong changes in lipoproteins and autoantibodies of blood serum of the Tundra Nency population as a result of environmental radiation on the territory they inhabit.

    PubMed

    Korovkina, E S; Tuzikov, F V; Tuzikova, N A; Osipova, L P; Buneva, V N; Nevinsky, G A

    2004-10-01

    As a result of large-scale nuclear tests on the Novaya Zemlya test site (1955-62) the Tundra Nentsy population of Yamal-Nentsy autonomous region (YNAR) fell under the constant influence of incorporated radioactive isotopes (137Cs and 90Sr). Therefore, it is very important to analyze a possible spectrum of diseases of Tundra Nentsy population.

  19. Geochemistry of Isla Santa Cruz, Galapagos Archipelago, Ecuador

    NASA Astrophysics Data System (ADS)

    Wilson, E. L.; Schwartz, D. M.; Van Kirk, R.; Harpp, K.

    2012-12-01

    The geochemistry of Galapagos volcanoes extends to more depleted signatures than most hotspots, and do not appear to follow a classical tholeiitic to alkalic evolutionary sequence (i.e., Hawaiian Islands). Thus far, no such predictable sequence has been identified for Galapagos volcanoes. Isla Santa Cruz is one of the oldest volcanoes in the archipelago. Bow (1979) identified 3 volcanic stages: the Platform Series, the Shield Series, and the Shield-Modifying stage. The Platform Series defines a liquid line of descent that differs from the one shared by the Shield and Shield-Modifying units, which are genetically related to each other. Within the Shield and Shield-Modifying lavas, K2O/TiO2 ratios reveal three distinct compositional sub-groups: 1) a MORB-like, low-K suite (<0.10); 2) a tholeiitic suite (0.10-0.25); and 3) an alkaline suite (>0.25). These 3 sub-groups are geographically distributed across the island; the low-K suite is only in the north, whereas the alkaline suite constitutes the center highlands and the tholeiitic suite is on the eastern and northern flanks. Variations in La/Sm and Sm/Yb indicate that the magmas supplying the Shield and Shield-Modifying units were generated over a wide range of melting conditions: the alkaline suite melts were generated at the greatest depths and from the smallest melt fraction of the three suites, whereas the low-K suite originates from shallower, greater extents of melting; the tholeiitic lavas were generated at depths intermediate between the other 2 sub-groups. None of the lavas from Santa Cruz resemble material erupted at Fernandina volcano, the presumed center of the plume; radiogenic isotope ratios from previous research indicate that all Santa Cruz lavas are significantly more depleted than western Galapagos lavas. The ~1.2 Ma Platform Series is the most enriched of the Santa Cruz units. The Shield and Shield-Modifying lavas are all shifted towards more depleted signatures, approaching those of MORB, in terms

  20. Geochemical heterogeneity of rivers draining the Canadian Arctic Archipelago

    NASA Astrophysics Data System (ADS)

    Alkire, M. B.; Jacobson, A. D.; Lehn, G. O.; Macdonald, R. W.; Rossi, M. W.

    2016-12-01

    River discharge contributes 38% of the annual freshwater input to the Arctic Ocean. While numerous studies have documented variations in the water discharge, sediment load, and geochemistry of the largest Arctic rivers (Ob, Yenisey, Lena, Kolyma, Mackenzie, and Yukon Rivers), there are hundreds of smaller rivers that remain ungauged and/or rarely sampled. Collectively, rivers draining the Canadian Arctic Archipelago and immediately adjacent regions (CAA) contribute 200-250 km3 yr-1 of freshwater to the Arctic and subarctic seas. This undocumented freshwater input complicates attempts to separate contributions from North American (i.e., Mackenzie River) and Siberian river discharges to the freshwater export through Davis Strait. In this study, we collected water samples from CAA rivers and their estuaries in order to characterize their geochemical composition and better constrain the collective impact of CAA rivers on the Arctic freshwater budget. Several variables (e.g., δ18O, Ba, nutrients, total alkalinity, DOC, major ions, and 87Sr/86Sr) were analyzed for water samples taken from ten different rivers extending across the CAA during spring (June-July) 2014 and summer (July-August) 2015. Major ion abundances mostly reflect mixing between carbonic acid weathering reactions and atmospheric deposition, with minimal contributions from sulfide oxidation. In general, rivers displaying higher solute concentrations drain the western and/or northern CAA, whereas those with lower concentrations drain the eastern and/or southern CAA. Geochemical signatures largely correlate with differences in bedrock geology, with the western and/or northern CAA comprising carbonate bedrock and the eastern and/or southern CAA comprising silicate bedrock. Combining these observations with GIS analyses, we assess the contributions of all watersheds in the CAA >100 km2 to develop a regional-scale assessment of solute and water delivery to CAA boundary currents.

  1. The peopling of Madeira Archipelago (Portugal) according to HLA genes.

    PubMed

    Arnaiz-Villena, A; Reguera, R; Ferri, A; Barbolla, L; Abd-El-Fatah-Khalil, S; Bakhtiyarova, N; Millan, P; Moscoso, J; Mafalda, A; Serrano-Vela, J I

    2009-02-01

    The Madeira-Porto Santo Archipelago was officially colonized in 1420 by Portuguese settlers. Its importance in Columbus' information for the American discovery and for slave traffic across the Atlantic is unquestionable. Thus, a complex peopling may have given rise to a present-day high admixture of ethnicities according to HLA genes. A sample of 173 healthy unrelated Madeirans was analysed and compared with 6986 HLA chromosomes from other worldwide populations. Genetic distances, neighbour-joining dendrograms and correspondence analyses were used for comparisons. Southern European, North African (including Canary Islands), Jewish and Mediterranean typical HLA alleles were found and genetic distances from Madeirans to these populations were the closest ones. In addition A*24-B*65-DRB1*0102-DQB1*0501 and A*68-B*08-DRB1*0301-DQB1*0201 haplotypes were newly found in Madeira and not found in any other population. Jewish-Armenian-Middle East haplotype (A*33-B*65-DRB1*0102-DQB1*0501) is one of the most common haplotypes; this haplotype is also present in Spaniards and North Africans. Quantitatively, Portuguese, North Africans (Algerians), Spaniards and Canary Islanders (in this order) are the most important parental populations to Madeirans. Results are discussed on the basis of the recorded historical peopling which does not show a noticeable African gene input in present-day Madeiran population according to our data; one of the closest related populations found is the Canary Islanders, suggesting that Guanche (Canary Islands first inhabitants) slaves gene flow is still noticed at present, both in Madeira and in Canary Islands populations.

  2. Transnational Mortality Comparisons Between Archipelago and Mainland Puerto Ricans.

    PubMed

    Colón-Ramos, Uriyoán; Rodríguez-Ayuso, Idania; Gebrekristos, Hirut T; Roess, Amira; Pérez, Cynthia M; Simonsen, Lone

    2016-06-22

    Puerto Ricans in the US experience higher deaths from diabetes and other causes compared to non-Hispanic Whites and other Hispanic groups. We compared mortality in Puerto Rico to that of Puerto Ricans in the US as a first step to investigate if similar or worse mortality patterns originate from the sending country (Puerto Rico). Age-adjusted death rates were generated using national vital statistics databases in the US and territories for all-cause and the top ten causes of death among Hispanics in 2009. Mortality ratios in the archipelago of Puerto Rico (APR) were compared to mainland US Puerto Ricans (MPR). Rates for other ethnic/racial groups (Mexican Americans, Cubans, and non-Hispanic Whites, Blacks, American Indians, and Asians) were calculated to provide a context. APR had significantly higher all-cause mortality and death rates for diabetes, nephritis, pneumonia/influenza, and homicide/assault compared to MPR (APR/MPR ratio for all-cause: 1.08, diabetes: 2.04, nephritis: 1.84, pneumonia/influenza: 1.33, homicide/assault: 3.15). Death rates for diabetes and homicide/assault (particularly among men) were higher among APR compared to any other racial/ethnic groups in the US. In contrast, deaths from heart disease, cancer, and chronic liver disease were significantly lower for APR compared to MPR (MPR/APR ratio 0.72, 0.91, 0.41, respectively). Among APR women, death rates for these causes were also lower compared to any other group in the US. Substantial mortality variability exists between Puerto Ricans in Puerto Rico and those in the US, re-emphasizing the need to study of how socio-environmental determinants of health differ in sending and receiving countries. Explanations for disparate rates include access to and availability of healthcare and unique factors related to the migration experience of this group.

  3. Elevation Changes of Ice Caps in the Canadian Arctic Archipelago

    NASA Technical Reports Server (NTRS)

    Abdalati, W.; Krabill, W.; Frederick, E.; Manizade, S.; Martin, C.; Sonntag, J.; Swift, R.; Thomas, R.; Yungel, J.; Koerner, R.

    2004-01-01

    Precise repeat airborne laser surveys were conducted over the major ice caps in the Canadian Arctic Archipelago in the spring of 1995 and 2000 in order to measure elevation changes in the region. Our measurements reveal thinning at lower elevations (below 1600 m) on most of the ice caps and glaciers, but either very little change or thickening at higher elevations in the ice cap accumulation zones. Recent increases in precipitation in the area can account for the slight thickening where it was observed, but not for the thinning at lower elevations. For the northern ice caps on the Queen Elizabeth Islands, thinning was generally less than 0.5 m/yr , which is consistent with what would be expected from the warm temperature anomalies in the region for the 5-year period between surveys and appears to be a continuation of a trend that began in the mid 1980s. Further south, however, on the Barnes and Penny ice caps on Baffin Island, this thinning was much more pronounced at over 1 m/yr in the lower elevations. Here temperature anomalies were very small, and the thinning at low elevations far exceeds any associated enhanced ablation. The observations on Barnes, and perhaps Penny are consistent with the idea that the observed thinning is part of a much longer term deglaciation, as has been previously suggested for Barnes Ice Cap. Based on the regional relationships between elevation and elevation-change in our data, the 1995-2000 mass balance for the region is estimated to be 25 cu km/yr of ice, which corresponds to a sea level increase of 0.064 mm/ yr . This places it among the more significant sources of eustatic sea level rise, though not as substantial as Greenland ice sheet, Alaskan glaciers, or the Patagonian ice fields.

  4. Viticultural zoning of Graciosa island of the Azores archipelago - Portugal

    NASA Astrophysics Data System (ADS)

    Madruga, João; Reis, Francisco; Felipe, João; Azevedo, Eduardo; Pinheiro, Jorge

    2016-04-01

    The management and sustainability of the traditional vineyards of the Azores settled on lava field terrains is strongly affected by practical limitations of mechanization and high demand on man labor imposed by the typical micro parcel structure of the vineyards. In a recent macrozoning approach study Madruga et al (2015) showed that besides the traditional vineyards there are significant areas in some of the Azores islands whose soils, climate and physiographic characteristics indicate a potential for the development of new vineyard areas offering conditions for better management and sustainability. The objective of this study was to conduct a detailed viticultural zoning at the level of the small mapscale (smaller than 1:25,000), for the island of Graciosa where, besides the traditional lava field terroir, there are also some localized experiences of grapevine production over normal soils, offering thus some comparative information on this type of production conditions. The zoning approach for the present study was based in a geographic information system (GIS) analysis incorporating factors related to climate and topography which was then combined with the soil mapping units fulfilling the suitable criteria concerning the soil properties taken as the most relevant for viticulture, being the result a map of homogeneous environmental units. The climatic zoning examined the direct quantitative variables (precipitation, temperature, evaporation) in relation to climate index, bioclimatic and viticultural specific values. Topography (elevation, slope, aspect, orientation) was analyzed based on the tridimensional models of the islands in GIS to include the best slopes for the mechanization of the vineyard cultural operations (0-15%). Soils were analyzed based on data and soil map units as defined in the soil surveys of the Azores archipelago. The soil properties taken for the analysis and definition of the potential vineyard areas were drainage, water holding capacity

  5. Soils of the Galindez Island, Argentine archipelago, Western Antarctica

    NASA Astrophysics Data System (ADS)

    Abakumov, Evgeny; Parnikoza, Ivan

    2015-04-01

    Antarctic Peninsula is a part of Antarctica which is characterized by increased soil diversity, caused by specific of parent materials and diversity of non-vascular and vascular plants. Soils of Galindez Island have been investigated during the 18-th Ukranian Antarctic Expedition 2013/14. This Island situated in Argentine archipelago (coastal part of Antarctic Peninsula). Soils of Galindez Island presented by following types: Leptosols, Lithosols, Histic Lithosols and Leptosols and some Gleyic soils, located in lowlands and coastal parts. An average solum profile thickness is 3-19 cm which result from the small depth of debris's, underplayed by massive crystallic rocks. The permafrost layer is located within the massive rock, but not in coarse friable parent material. The soils with bird influence are widely spread both in coastal and central part of Island. In the coastal parts we can find typical Ornithosols in the penguin rockeries areas. The main aim of our investigation was characterization of soils formed under vegetation, exactly under Deschampsia antarctica Desv. localities. Argentine Islands is the central part of D. antarctica spreading area in region of Antarctic peninsula. Probably, these islands colonized by hairgrass mainly due to ornitogenic activity. So, coastal population appearance related with Larus dominicanus nest areas and feeding activity. Thus, we found typical post ornithogenic soils here. This kind of soils we also observed in population of hairgrass of Galindez mainland where it was connected with the other Antarctic bird - Catharacta maccormicki activity. Thus, the soil diversity and soil geochemistry of the Galindez Island are closely related to the activity of birds. The spatial pattern of soils, their chemistry and organic matter quality is discussed in relation with distribution of bird nesting and feeding activity.

  6. Is the Hawaiian Archipelago dominantly Loa-trend?

    NASA Astrophysics Data System (ADS)

    Weis, D.; Harrison, L.; Garcia, M. O.; Rhodes, M. M.

    2015-12-01

    Hawaiian volcanoes are distributed en echelon on the islands along two chains, the Loa and Kea trends, that are geographically and geochemically distinct1,2. These geochemical differences may be attributed to source zoning (concentric or bilateral) of the Hawaiian mantle plume (HMP) or to variations in pressure and temperature of melting. Most of these models assume a degree of independence of the two trends that is perhaps not realistic. To explore the isotopic characteristics of two "Kea"-trend volcanoes with transitional signatures, we analyzed 11 samples of Kohala shield-stage tholeiitic lavas and three from Haleakala for high-precision Pb-Nd-Sr-Hf isotopes. These samples are transitional in all isotopic systems between Loa and Kea compositions and cross-over the Pb-Pb boundary3. Minor cross-overs had been documented in Mauna Kea4, Kilauea5, and W Molokai6 basalts. A bilateral or concentric view of the HMP is thus too simplistic. Statistical analysis of the MC-ICP-MS or triple-spike shield tholeiite data (n>600) and the existence of three Pb-Pb trends originating from average Loa indicate that Loa is the dominant mantle source composition on the archipelago. Isotopically, four geochemical groups are identified: Kea (Mauna Kea, Kilauea), average Loa (Mauna Loa, Hualalai, Kauai, Waianae, W. Molokai, Loihi), enriched Loa (Koolau Makapuu, Lanai, Kahoolawe) and transitional Kea (E. Molokai, W. Maui, Haleakala, Kohala). The implications are: 1) HMP source components refresh and grade into and out of existence on a smaller timescale than previously thought; 2) the Kea trend is also heterogeneous; and 3) vertical heterogeneity of the plume is important on a regional scale as well as at the scale of individual volcanoes6. 1Jackson et al., 1972, GSA Bull. 83, 1-17. 2Weis et al., 2011, Nat. Geosci., 4, 831-838. 3Abouchami et al., 2005, Nature, 434, 851-856. 4Eisele et al., 2003, G-cubed, 4, 5, 32 pages. 5Marske et al., 2007, EPSL, 259, 34-50. 6Xu et al., 2014, GCA, 132

  7. Monitoring Fogo Island, Cape Verde Archipelago, for Volcanic Hazard Mitigation

    NASA Astrophysics Data System (ADS)

    Faria, B. V.; Heleno, S. I.; Barros, I. J.; d'Oreye, N.; Bandomo, Z.; Fonseca, J. F.

    2001-12-01

    Fogo Island, in the Cape Verde Archipelago (North Atlantic), with a total area of 476 km2 and a population of about 40000, is an active ocean island volcano raising from an average sea-bottom depth of the order of -3000m to a maximum altitude of 2820m. All of the 28 historically recorded eruptions (Ribeiro, 1960) since the arrival of the first settlers in the 15th Century took place in Cha das Caldeiras, a 9 km-wide flat zone 1700 meters above sea level that resulted from the infill of a large lateral collapse caldera (Day et al., 2000). The last eruptions occurred in 1951 and 1995, through secondary cones at the basis of Pico do Fogo, the main volcanic edifice. A tall scarp surrounds Cha das Calderas on its western side only, and the eastern limit leads to a very steep sub-aerial slope down to the coastline. With this morphology, the volcanic hazard is significant inside Cha das Caldeiras - with a resident population of the order of 800 - and particularly in the villages of the eastern coast. Because the magma has low viscosity, eruptions in Fogo have scarce precursory activity, and its forecast is therefore challenging. The VIGIL monitoring network was installed between 1997 and 2001, and is currently in full operation. It consists of seven seismographic stations - two of which broadband - four tilt stations, a CO2 monitoring station and a meteo station. The data is telemetred in real time to the central laboratory in the neighbor island of Santiago, and analyzed on a daily basis. The continuous data acquisition is complemented by periodic GPS, gravity and leveling surveys (Lima et al., this conference). In this paper we present the methodology adopted to monitor the level of volcanic activity of Fogo Volcano, and show examples of the data being collected. Anomalous data recorded at the end of September 2000, which led to the only occurrence of an alert warning so far, are also presented and discussed.

  8. Risk Factors of Typhoid Infection in the Indonesian Archipelago

    PubMed Central

    Alba, Sandra; Bakker, Mirjam I.; Hatta, Mochammad; Scheelbeek, Pauline F. D.; Dwiyanti, Ressy; Usman, Romi; Sultan, Andi R.; Sabir, Muhammad; Tandirogang, Nataniel; Amir, Masyhudi; Yasir, Yadi; Pastoor, Rob; van Beers, Stella; Smits, Henk L.

    2016-01-01

    Background Knowledge of risk factors and their relative importance in different settings is essential to develop effective health education material for the prevention of typhoid. In this study, we examine the effect of household level and individual behavioural risk factors on the risk of typhoid in three Indonesian islands (Sulawesi, Kalimantan and Papua) in the Eastern Indonesian archipelago encompassing rural, peri-urban and urban areas. Methods We enrolled 933 patients above 10 years of age in a health facility-based case-control study between June 2010 and June 2011. Individuals suspected of typhoid were tested using the typhoid IgM lateral flow assay for the serodiagnosis of typhoid fever followed by blood culture testing. Cases and controls were defined post-recruitment: cases were individuals with a culture or serology positive result (n = 449); controls were individuals negative to both serology and culture, with or without a diagnosis other than typhoid (n = 484). Logistic regression was used to examine the effect of household level and individual level behavioural risk factors and we calculated the population attributable fraction (PAF) of removing each risk significant independent behavioural risk factor. Results Washing hands at critical moments of the day and washing hands with soap were strong independent protective factors for typhoid (OR = 0.38 95% CI 0.25 to 0.58 for each unit increase in hand washing frequency score with values between 0 = Never and 3 = Always; OR = 3.16 95% CI = 2.09 to 4.79 comparing washing hands with soap sometimes/never vs. often). These effects were independent of levels of access to water and sanitation. Up to two thirds of cases could be prevented by compliance to these practices (hand washing PAF = 66.8 95% CI 61.4 to 71.5; use of soap PAF = 61.9 95%CI 56.7 to 66.5). Eating food out in food stalls or restaurant was an important risk factor (OR = 6.9 95%CI 4.41 to 10.8 for every unit increase in frequency score

  9. Risk Factors of Typhoid Infection in the Indonesian Archipelago.

    PubMed

    Alba, Sandra; Bakker, Mirjam I; Hatta, Mochammad; Scheelbeek, Pauline F D; Dwiyanti, Ressy; Usman, Romi; Sultan, Andi R; Sabir, Muhammad; Tandirogang, Nataniel; Amir, Masyhudi; Yasir, Yadi; Pastoor, Rob; van Beers, Stella; Smits, Henk L

    2016-01-01

    Knowledge of risk factors and their relative importance in different settings is essential to develop effective health education material for the prevention of typhoid. In this study, we examine the effect of household level and individual behavioural risk factors on the risk of typhoid in three Indonesian islands (Sulawesi, Kalimantan and Papua) in the Eastern Indonesian archipelago encompassing rural, peri-urban and urban areas. We enrolled 933 patients above 10 years of age in a health facility-based case-control study between June 2010 and June 2011. Individuals suspected of typhoid were tested using the typhoid IgM lateral flow assay for the serodiagnosis of typhoid fever followed by blood culture testing. Cases and controls were defined post-recruitment: cases were individuals with a culture or serology positive result (n = 449); controls were individuals negative to both serology and culture, with or without a diagnosis other than typhoid (n = 484). Logistic regression was used to examine the effect of household level and individual level behavioural risk factors and we calculated the population attributable fraction (PAF) of removing each risk significant independent behavioural risk factor. Washing hands at critical moments of the day and washing hands with soap were strong independent protective factors for typhoid (OR = 0.38 95% CI 0.25 to 0.58 for each unit increase in hand washing frequency score with values between 0 = Never and 3 = Always; OR = 3.16 95% CI = 2.09 to 4.79 comparing washing hands with soap sometimes/never vs. often). These effects were independent of levels of access to water and sanitation. Up to two thirds of cases could be prevented by compliance to these practices (hand washing PAF = 66.8 95% CI 61.4 to 71.5; use of soap PAF = 61.9 95%CI 56.7 to 66.5). Eating food out in food stalls or restaurant was an important risk factor (OR = 6.9 95%CI 4.41 to 10.8 for every unit increase in frequency score). Major gains could potentially be

  10. Tsunami hazard assessment for the Azores archipelago: a historical review

    NASA Astrophysics Data System (ADS)

    Cabral, Nuno; Ferreira, Teresa; Queiroz, Maria Gabriela

    2010-05-01

    The Azores islands due to its complex geographical and geodynamic setting are exposed to tsunamigenic events associated to different triggering mechanisms, local or distant. Since the settlement of the Azores, in the fifteenth century, there are several documents that relate coastal areas flooding episodes with unusually high waves which caused death and destruction. This work had as main objective the characterization of the different events that can be associated with tsunamigenic phenomena, registered in the archipelago. With this aim, it was collected diverse documentation like chronics, manuscripts, newspaper articles and magazines, scientific publications, and international databases available online. From all the studied tsunami events it was identified the occurrence of some teletsunamis, among which the most relevant was triggered by the 1st November 1755 Lisbon earthquake, with an epicenter SW of Portugal, which killed 6 people in Terceira island. It is also noted the teletsunami generated by the 1761 earthquake, located in the same region as the latest, and the one generated in 1929 by an earthquake-triggered submarine landslide in the Grand Banks of Newfoundland. From the local events, originated in the Azores, the most significant were the tsunamis triggered by 1757 and 1980 earthquakes, both associated with the Terceira Rift dynamics. In the first case the waves may also be due to earthquake-triggered. With respect to tsunamis triggered by sea cliffs landslides it is important to mention the 1847 Quebrada Nova and the 1980 Rocha Alta events, both located in the Flores Island. The 1847 event is the deadliest tsunami recorded in Azores since 10 people died in Flores and Corvo islands in result of the propagated wave. The developed studies improve knowledge of the tsunami sources that affected the Azores during its history, also revealing the importance of awareness about this natural phenomenon. The obtained results showed that the tsunami hazard in the

  11. Emergence of rabbit haemorrhagic disease virus 2 in the archipelago of Madeira, Portugal (2016-2017).

    PubMed

    Carvalho, Carina Luísa; Silva, Sara; Gouveia, Paz; Costa, Margarida; Duarte, Elsa Leclerc; Henriques, Ana Margarida; Barros, Sílvia Santos; Luís, Tiago; Ramos, Fernanda; Fagulha, Teresa; Fevereiro, Miguel; Duarte, Margarida Dias

    2017-06-21

    We report the detection of rabbit haemorrhagic disease virus 2 (RHDV2) in the Madeira archipelago, Portugal. Viral circulation was confirmed by RT-qPCR and vp60 sequencing. Epidemiological data revealed the outbreak initiated in October 2016 in Porto Santo affecting wild and domestic rabbits. It was then detected three months later on the island of Madeira. Five haplotypes were identified and a genetic overall similarity of 99.54 to 99.89% was observed between the two viral populations. Unique single nucleotide polymorphisms were recognised in the Madeira archipelago strains, two of which resulting in amino acid substitutions at positions 480 and 570 in the VP60 protein. Phylogenetic investigation by Maximum Likelihood showed all the vp60 sequences from the Madeira archipelago group together with high bootstraps. The analysis also showed that the Madeira archipelago strains are closely related to the strains detected in the south of mainland Portugal in 2016, suggesting a possible introduction from the mainland. The epidemiological data and high genetic similarity indicate a common source for the Porto Santo and Madeira RHDV2 outbreaks. Human activity related to hunting was most probably at the origin of the Madeira outbreak.

  12. Tropical Instability Wave Interactions within the Galápagos Archipelago.

    EPA Science Inventory

    In the boreal fall of 2005, the effects of tropical instability waves (TIW) appear as oscillations within the sea surface temperature (SST), meridional current (Vy), and thermocline (20°C) in the eastern equatorial Pacific. Within the Galápagos Archipelago, a strong 3-wave succes...

  13. Connecting mountain islands and desert seas: Biodiversity and management of the Madrean Archipelago II

    Treesearch

    Gerald J. Gottfried; Brooke S. Gebow; Lane G. Eskew; Carleton B. Edminster

    2005-01-01

    The Madrean Archipelago, or Sky Island, region of the southwestern United States and northern Mexico is recognized for its great biological diversity and natural beauty. This conference brought together scientists, managers, and other interested parties to share their knowledge about the region and to identify needs and possible solutions for existing and emerging...

  14. Tropical Instability Wave Interactions within the Galápagos Archipelago.

    EPA Science Inventory

    In the boreal fall of 2005, the effects of tropical instability waves (TIW) appear as oscillations within the sea surface temperature (SST), meridional current (Vy), and thermocline (20°C) in the eastern equatorial Pacific. Within the Galápagos Archipelago, a strong 3-wave succes...

  15. Biodiversity and management of the Madrean Archipelago II: Summary of discussions during the concluding session

    Treesearch

    Gerald J. Gottfried; Peter F. Ffolliott; Brooke S. Gebow; Shelley Danzer; Laura Arriaga; Daniel G. Neary; Van Devender; Thomas R.

    2005-01-01

    The first Conference on Biodiversity and Management of the Madrean Archipelago brought together scientists, managers, and other interested parties from the United States and Mexico to share their knowledge about the region and to identify the needs and possible solutions for the future. The 1994 conference ended with an open discussion among the participants. The...

  16. Megachile timberlakei Cockerell (Hymenoptera: Megachilidae): Yet another adventive bee species to the Galapagos Archipelago

    USDA-ARS?s Scientific Manuscript database

    The Galapagos Archipelago has been thought to be extremely depauperate in bees, with only one species known, Xylocopa darwini. Recently a second species, Anthidium vigintiduopunctatum, was detected. Here we document a third species, Megachile timberlakei. We provide floral records as well as a dia...

  17. Identification of metapopulation dynamics among Northern Goshawks of the Alexander Archipelago, Alaska, and Coastal British Columbia

    USGS Publications Warehouse

    Sonsthagen, Sarah A.; McClaren, Erica L.; Doyle, Frank I.; Titus, K.; Sage, George K.; Wilson, Robert E.; Gust, Judy R.; Talbot, Sandra L.

    2012-01-01

    Northern Goshawks occupying the Alexander Archipelago, Alaska, and coastal British Columbia nest primarily in old-growth and mature forest, which results in spatial heterogeneity in the distribution of individuals across the landscape. We used microsatellite and mitochondrial data to infer genetic structure, gene flow, and fluctuations in population demography through evolutionary time. Patterns in the genetic signatures were used to assess predictions associated with the three population models: panmixia, metapopulation, and isolated populations. Population genetic structure was observed along with asymmetry in gene flow estimates that changed directionality at different temporal scales, consistent with metapopulation model predictions. Therefore, Northern Goshawk assemblages located in the Alexander Archipelago and coastal British Columbia interact through a metapopulation framework, though they may not fit the classic model of a metapopulation. Long-term population sources (coastal mainland British Columbia) and sinks (Revillagigedo and Vancouver islands) were identified. However, there was no trend through evolutionary time in the directionality of dispersal among the remaining assemblages, suggestive of a rescue-effect dynamic. Admiralty, Douglas, and Chichagof island complex appears to be an evolutionarily recent source population in the Alexander Archipelago. In addition, Kupreanof island complex and Kispiox Forest District populations have high dispersal rates to populations in close geographic proximity and potentially serve as local source populations. Metapopulation dynamics occurring in the Alexander Archipelago and coastal British Columbia by Northern Goshawks highlight the importance of both occupied and unoccupied habitats to long-term population persistence of goshawks in this region.

  18. Tuamotu Archipelago in South Pacific as seen from the Apollo 7 spacecraft

    NASA Image and Video Library

    1968-10-21

    AS07-04-1590 (20 Oct. 1968) --- Tuamotu Archipelago in the South Pacific Ocean, looking southwest, as photographed from the Apollo 7 spacecraft during its 141st revolution of Earth. The photograph was taken from an altitude of 110 nautical miles, at a ground elapsed time of 224 hours and 18 minutes.

  19. Prehistoric inter-archipelago trading of Polynesian tree snails leaves a conservation legacy

    PubMed Central

    Lee, Taehwan; Burch, John B; Coote, Trevor; Fontaine, Benoît; Gargominy, Olivier; Pearce-Kelly, Paul; Foighil, Diarmaid Ó

    2007-01-01

    Inter-archipelago exchange networks were an important aspect of prehistoric Polynesian societies. We report here a novel genetic characterization of a prehistoric exchange network involving an endemic Pacific island tree snail, Partula hyalina. It occurs in the Society (Tahiti only), Austral and Southern Cook Islands. Our genetic data, based on museum, captive and wild-caught samples, establish Tahiti as the source island. The source lineage is polymorphic in shell coloration and contains a second nominal species, the dark-shelled Partula clara, in addition to the white-shelled P. hyalina. Prehistoric inter-island introductions were non-random: they involved white-shelled snails only and were exclusively inter-archipelago in scope. Partulid shells were commonly used in regional Polynesian jewellery, and we propose that the white-shelled P. hyalina, originally restricted to Tahiti, had aesthetic value throughout these archipelagoes. Demand within the Society Islands could be best met by trading dead shells, but a low rate of inter-archipelago exchange may have prompted the establishment of multiple founder populations in the Australs and Southern Cooks. The alien carnivorous land snail Euglandina rosea has recently devastated populations of all 61 endemic species of Society Island partulid snails. Southern Cooks and Australs P. hyalina now represent the only unscathed wild populations remaining of this once spectacular land snail radiation. PMID:17848368

  20. Prehistoric inter-archipelago trading of Polynesian tree snails leaves a conservation legacy.

    PubMed

    Lee, Taehwan; Burch, John B; Coote, Trevor; Fontaine, Benoît; Gargominy, Olivier; Pearce-Kelly, Paul; Foighil, Diarmaid O

    2007-11-22

    Inter-archipelago exchange networks were an important aspect of prehistoric Polynesian societies. We report here a novel genetic characterization of a prehistoric exchange network involving an endemic Pacific island tree snail, Partula hyalina. It occurs in the Society (Tahiti only), Austral and Southern Cook Islands. Our genetic data, based on museum, captive and wild-caught samples, establish Tahiti as the source island. The source lineage is polymorphic in shell coloration and contains a second nominal species, the dark-shelled Partula clara, in addition to the white-shelled P. hyalina. Prehistoric inter-island introductions were non-random: they involved white-shelled snails only and were exclusively inter-archipelago in scope. Partulid shells were commonly used in regional Polynesian jewellery, and we propose that the white-shelled P. hyalina, originally restricted to Tahiti, had aesthetic value throughout these archipelagoes. Demand within the Society Islands could be best met by trading dead shells, but a low rate of inter-archipelago exchange may have prompted the establishment of multiple founder populations in the Australs and Southern Cooks. The alien carnivorous land snail Euglandina rosea has recently devastated populations of all 61 endemic species of Society Island partulid snails. Southern Cooks and Australs P. hyalina now represent the only unscathed wild populations remaining of this once spectacular land snail radiation.

  1. Turbinaria ornata invasion in the Tuamotu Archipelago, French Polynesia: ocean drift connectivity

    NASA Astrophysics Data System (ADS)

    Martinez, Elodie; Maamaatuaiahutapu, Keitapu; Payri, Claude; Ganachaud, Alexandre

    2007-03-01

    This paper focuses on the invasion by Turbinaria ornata (a brown algae) in the Tuamotu archipelago, French Polynesia [(5-35°S)/(200-230°E)]. Prior to 1980, this alga existed only in the Society and Austral archipelagoes. Between 1985 and 1990, it began to appear in the southern and northern parts of the Tuamotu archipelago. Genetic analyses have been shown not to be appropriate in determining the origin of this algae population. This study investigated the possible ocean drift of floating aggregates of algae. Ocean currents were calculated from satellite data from 1993 to 2001. Their spatial variations as well as their seasonal and interannual variations are described along with calculated drift trajectories. While it was found that mean currents cannot directly transport algae from the Society and Austral archipelagoes to the Tuamotu, the large interannual changes during the El Niño-Southern Oscillation phenomenon produce current reversals that are strong enough to create a transport pathway in a short enough time to allow their survival.

  2. Checklist and analysis of completeness of the reef fish fauna of the Revillagigedo Archipelago, Mexico.

    PubMed

    Fourriére, Manon; Reyes-Bonilla, Héctor; Ayala-Bocos, Arturo; Ketchum, James A; Chávez-Comparan, Juan Carlos

    2016-08-15

    This paper presents an updated checklist of cartilaginous and bony fishes from the Revillagigedo Archipelago reefs and nearby areas (Tropical Eastern Pacific). To compile this list, we gathered data from field surveys between 1994 and 2015, from an exhaustive literature review, and by consulting museum collections and databases. With these records we estimated the completeness of the local fish inventory using four non-parametric rarefaction methods. We report a total of 389 species in 102 families; 235 of these are reef fish that occur in the Eastern but also in the Central Pacific, and 13 species were identified as endemic to the archipelago. A non-parametric statistical model predicts that the expected number of reef fish present at Revillagigedo should be 244.3 ± 3.2 species, which is 9 species more than the observed richness, and this difference was statistically significant (p = 0.02). That predictive model estimates that about 96% of the total richness of reef fish from the archipelago is known. Comparisons of the completeness of the inventory at Revillagigedo to that reported for the fish fauna of the Eastern Pacific and worldwide, showed that the quality of the sampling effort is remarkably high, in spite of the geographic isolation of the archipelago.

  3. Hydrology, ecology, and management of riparian areas in the Madrean Archipelago [Abstract

    Treesearch

    Daniel G. Neary; Peter F. Ffolliott; Leonard F. DeBano

    2005-01-01

    Riparian corridors in the Madrean Archipelago have historically provided water necessary for people, livestock, and agricultural crops. Anglo settlers during the 1800s were attracted to riparian areas in this arid and semi-arid region where they enjoyed the forage and shade for themselves and their livestock and existed on the readily available wildlife and fish. Trees...

  4. Hydrology, ecology, and management of riparian areas in the Madrean Archipelago

    Treesearch

    Daniel G. Neary; Peter F. Ffolliott; Leonard F. DeBano

    2005-01-01

    Riparian areas in the Madrean Archipelago have historically provided water necessary for people, livestock, and agricultural crops. European settlers were attracted to these areas in the 1880s, where they enjoyed shade and forage for themselves and their livestock and existed on the readily available wildlife and fish. Trees growing along stream banks were harvested...

  5. Creole-based Trilingual Education in the Caribbean Archipelago of San Andres, Providence and Santa Catalina.

    ERIC Educational Resources Information Center

    Morren, Ronald C.

    2002-01-01

    Depicts the impetus and drive behind the development of a primary trilingual education curriculum for the Western Caribbean Archipelago of San Andre, Providence, and Santa Catalina. Based on outcomes in other multilingual education projects, hypothesizes positive academic gains in all areas at a cost benefit to the national government. (Author/VWL)

  6. Nutrient management for coastal zones: a case study of the nitrogen load to the Stockholm Archipelago.

    PubMed

    Scharin, H

    2002-01-01

    This study investigates cost-effective solutions of decreasing the nutrient load to a coastal area, using a drainage basin approach. The study is applied to the Stockholm Archipelago, a coastal area of the Baltic Sea suffering from eutrophication caused by the load of nutrients entering the area. Nitrogen is the nutrient of concern in this study since it is the limiting nutrient of the Archipelago. The main sources of nitrogen are wastewater plants, agriculture, and atmospheric depositions. The final impact of a deposition depends on the buffering capabilities it is subject to on its trajectory from the source to the recipient. This is the reason for using a recipient oriented approach, in which the focus is to reduce the final impact of a deposition. The model integrates data over hydrology, land cover, land use, and economy in order to find the optimal allocation of measures. Results indicate that in order to achieve cost effectiveness, the major part of nitrogen load reduction to the Archipelago should be done at the wastewater plants and by constructing wetlands. The minimum annual cost of reaching a 50% reduction of the load to the Archipelago was estimated to around 191 million Swedish crowns (around $19 million).

  7. Anthidium vigintiduopunctatum Friese (Hymenoptera: Megachilidae): The elusive "dwarf bee" of the Galapagos Archipelago

    USDA-ARS?s Scientific Manuscript database

    The endemic large carpenter bee, Xylocopa darwini Cockerell, was the only known bee pollinator to the Galapagos Archipelago but as early as 1964 locals also spoke of the "dwarf bee of Floreana". We report the presence of the wool carder bee, Anthidium vigintiduopunctatum Friese, on the island of Fl...

  8. Dissemination of antibiotic resistant Enterococcus spp. and Escherichia coli from wild birds of Azores Archipelago.

    PubMed

    Santos, Tiago; Silva, Nuno; Igrejas, Gilberto; Rodrigues, Pedro; Micael, Joana; Rodrigues, Tiago; Resendes, Roberto; Gonçalves, Alexandre; Marinho, Catarina; Gonçalves, David; Cunha, Regina; Poeta, Patrícia

    2013-12-01

    Antibiotic-resistant is profoundly important to human and animal health, but the environmental reservoirs of resistance determinants are poorly understood, in particular in wild environments in remote Archipelagos. Moreover, the prevalence of antibiotic-resistant bacteria in wild bird populations is rather unknown. In the present study, we used the Azores Islands as a model study for antimicrobial resistance in a remote Archipelago, and examined the antibiotic resistance profile in enterococci and Escherichia coli recovered from faecal samples of wild birds collected in this Archipelago. A total of 138 enterococci and 115 E. coli isolates were analyzed for resistance to antimicrobial agents. Of the enterococcal isolates, Enterococcus faecalis was the most prevalent detected species (59 isolates), followed by Enterococcus faecium (40 isolates), Enterococcus durans (27 isolates) and Enterococcus hirae (12 isolates). The enterococci strains showed high percentages of resistance to tetracycline (32.6%), to ciprofloxacin (19.6%) and to erythromycin (11.6%). Lower level of resistance (<10%) was detected for ampicillin, chloramphenicol and teicoplanin. One vancomycin-resistant E. faecalis isolate was detected and harbored the vanA resistant gene. Resistance genes detected included tet(M) and/or tet(L), ermB in all tetracycline and erythromycin-resistant isolates. Resistance in E. coli isolates was detected for ampicillin, tetracycline, sulfamethoxazole/trimethoprim, streptomycin, and tobramycin. The blaTEM, aadA, aadA5, strA, strB, tet(A) and/or tet(B), and the intI genes were found in all ampicillin, streptomycin, tetracycline, and sulfamethoxazole/trimethoprim-resistant isolates respectively. The data shown in this study are essential to improve knowledge about the dissemination of resistant strains through wild birds from remote archipelagos such as the Azores Archipelago and the possible implications involved in transferring these resistances either to other animals

  9. Holocene paleoceanography of the northwest passage, Canadian Arctic Archipelago

    NASA Astrophysics Data System (ADS)

    Ledu, David; Rochon, André; de Vernal, Anne; St-Onge, Guillaume

    2010-12-01

    A series of cores (box and piston) were collected at 2 key locations in Lancaster Sound (cores 2004-804-009 BC and PC) and Barrow Strait (cores 2005-804-004 BC and PC) in the Canadian Arctic Archipelago to document the evolution of sea-surface conditions in the main axis of the Northwest Passage during the Holocene time period. Reconstruction of sea-surface parameters (summer temperature and salinity, duration of sea-ice cover) were estimated based on transfer functions using dinoflagellate cyst assemblages as proxy indicators. The chronology of these cores is based on calibrated AMS- 14C dates, 210Pb analyses, and correlations between paleomagnetic secular variations of the geomagnetic field and a predicted spherical harmonic model of the geomagnetic field (CALS7 K.2). Our age models for both cores indicate that 009 PC spans the last 11,100 cal BP, while 004 PC encompasses the last 10,800 cal BP. Calculated sedimentation rates are in the range of 43-140 cm/kyr for core 009 PC and 15-118 cm/kyr for core 004 PC, allowing for a millennial time scale resolution in each core. Our results indicate relatively harsh conditions in Lancaster Sound between 10,800 and 9000 cal BP (summer temperatures 2 °C cooler than at present), which we associate with the presence of active ice-streams in northernmost Baffin Bay and a weak West Greenland Current. This is followed by a warming trend (up to 3 °C higher than present) that took place between ˜8500 and 5500 cal BP, which we associate with the Holocene thermal maximum and to a large scale atmospheric pattern such as the Arctic Oscillation operating at the millennial time scale. This is concomitant with an increase in the relative abundance of phototrophic dinoflagellate cyst taxa. A gradual cooling of sea-surface temperature and increased sea-ice follow this from 5500 cal BP until the modern period. In Barrow Strait, harsh sea-surface conditions prevailed from 11,100 to 5500 cal BP, with summer temperatures as low as 4

  10. Multi Hazard Assessment: The Azores Archipelagos (PT) case

    NASA Astrophysics Data System (ADS)

    Aifantopoulou, Dorothea; Boni, Giorgio; Cenci, Luca; Kaskara, Maria; Kontoes, Haris; Papoutsis, Ioannis; Paralikidis, Sideris; Psichogyiou, Christina; Solomos, Stavros; Squicciarino, Giuseppe; Tsouni, Alexia; Xerekakis, Themos

    2016-04-01

    The COPERNICUS EMS Risk & Recovery Mapping (RRM) activity offers services to support efficient design and implementation of mitigation measures and recovery planning based on EO data exploitation. The Azores Archipelagos case was realized in the context of the FWC 259811 Copernicus EMS RRM, and provides potential impact information for a number of natural disasters. The analysis identified population and assets at risk (infrastructures and environment). The risk assessment was based on hazard and vulnerability of structural elements, road network characteristics, etc. Integration of different hazards and risks was accounted in establishing the necessary first response/ first aid infrastructure. EO data (Pleiades and WV-2), were used to establish a detailed background information, common for the assessment of the whole of the risks. A qualitative Flood hazard level was established, through a "Flood Susceptibility Index" that accounts for upstream drainage area and local slope along the drainage network (Manfreda et al. 2014). Indicators, representing different vulnerability typologies, were accounted for. The risk was established through intersecting hazard and vulnerability (risk- specific lookup table). Probabilistic seismic hazards maps (PGA) were obtained by applying the Cornell (1968) methodology as implemented in CRISIS2007 (Ordaz et al. 2007). The approach relied on the identification of potential sources, the assessment of earthquake recurrence and magnitude distribution, the selection of ground motion model, and the mathematical model to calculate seismic hazard. Lava eruption areas and a volcanic activity related coefficient were established through available historical data. Lava flow paths and their convergence were estimated through applying a cellular, automata based, Lava Flow Hazard numerical model (Gestur Leó Gislason, 2013). The Landslide Hazard Index of NGI (Norwegian Geotechnical Institute) for heavy rainfall (100 year extreme monthly rainfall

  11. Colonization of the Hawaiian Archipelago via Johnston Atoll: a characterization of oceanographic transport corridors for pelagic larvae using computer simulation

    NASA Astrophysics Data System (ADS)

    Kobayashi, Donald R.

    2006-08-01

    Larval transport between Johnston Atoll and the Hawaiian Archipelago was examined using computer simulation and high-resolution ocean current data. The effects of pelagic larval duration and spawning seasonality on long-distance transport and local retention were examined using a Lagrangian, individual-based approach. Retention around Johnston Atoll appeared to be low, and there appeared to be seasonal effects on both retention and dispersal. Potential larval transport corridors between Johnston Atoll and the Hawaiian Archipelago were charted. One corridor connects Johnston Atoll with the middle portion of the Hawaiian Archipelago in the vicinity of French Frigate Shoals. Another corridor connects Johnston Atoll with the lower inhabited islands in the vicinity of Kauai. Transport appears to be related to the subtropical countercurrent and the Hawaiian Lee countercurrent, both located to the west of the archipelago and flowing to the east. A new analytical tool, termed CONREC-IRC is presented for the quantification of spatial patterns.

  12. Timing and number of colonizations but not diversification rates affect diversity patterns in hemosporidian lineages on a remote oceanic archipelago.

    PubMed

    Cornuault, Josselin; Warren, Ben H; Bertrand, Joris A M; Milá, Borja; Thébaud, Christophe; Heeb, Philipp

    2013-12-01

    Parasite diversity on remote oceanic archipelagos is determined by the number and timing of colonizations and by in situ diversification rate. In this study, we compare intra-archipelago diversity of two hemosporidian parasite genera, Plasmodium and Leucocytozoon, infecting birds of the Mascarene archipelago. Despite the generally higher vagility of Plasmodium parasites, we report a diversity of Plasmodium cytochrome b haplotypes in the archipelago much lower than that of Leucocytozoon. Using phylogenetic data, we find that this difference in diversity is consistent with differences in the timing and number of colonizations, while rates of diversification do not vary significantly between the two genera. The prominence of immigration history in explaining current diversity patterns highlights the importance of historical contingencies in driving disparate biogeographic patterns in potentially harmful blood parasites infecting island birds.

  13. Redescription of Bradya typica Boeck, 1873 (Copepoda: Harpacticoida: Ectinosomatidae) with the first description of the male

    NASA Astrophysics Data System (ADS)

    Seifried, Sybille; Veit-Köhler, Gritta

    2010-03-01

    Bradya typica Boeck, 1873 is described from samples collected in the course of a colonisation experiment in Kongsfjorden, Spitsbergen (2003-2005). The male of B. typica, the type-species of the genus is described for the first time. B. typica can be distinguished from its congeners by its caudal rami (1.4 times longer than wide) and by its P5 (exopod longer than wide, inner terminal seta of exopod longest, inner seta of baseoendopod longer than outer one and surface seta rigid and curved). Variability within the species is rather small as only the length of some setae is slightly different. B. cladiofera Lang, 1965, B. congenera Sars, 1920, B. minutiseta Soyer, 1973 and B. pugiochaeta Arlt, 1983 are closely related to B. typica. Some details of the morphology, such as the body ornamentation and the longer hair-like pinnules on the spines of the swimming legs, are very difficult to observe even with maximum magnification. With certainty, B. typica is distributed near the Norwegian coast (Oslo Fjord to Trondheim Fjord), the Swedish coast (Skagerak to Öresund), around Spitsbergen and around the polar islands north of Grinnelland (Canadian Arctic Archipelago near Baffin Bay). Records of B. typica from the Kara Sea (near Novaya Zemlya), near Franz Joseph Land, Iceland, Greenland, the British Isles and from deep waters of the North Sea have to be confirmed.

  14. Downslope windstorms in Russia

    NASA Astrophysics Data System (ADS)

    Shestakova, Anna; Toropov, Pavel; Moiseenko, Konstantin

    2017-04-01

    Downslope windstorms occur on the leeward slopes of mountain ranges in many mountain areas of the world when the optimal combination of synoptic and orographic conditions appears. Such phenomenon is characterized by gusty wind with maximum velocity up to 60 m/s and rapid changes in temperature.At the present time, the most studied downslope winds are Adriatic bora, winds of the Rocky Mountains in the United States (including chinook), the Alpine foёhn. In Russia, such winds are observed on Novaya Zemlya archipelago, on Lake Baikal (Sarma), in the Urals (Kizelovskaya bora), in the Crimea, in Pevek, at the Black Sea coast of the Caucasus (Novorossiysk bora). The aim of this work is to study the role of different physical mechanisms in the formation of the strongest and most illuminated by observational data downslope windstorms in Russia, which is Novorossiysk bora, Novaya Zemlya bora and windstorm in Pevek. These winds are located in different climatic zones and orographic conditions, however, they may have similar mechanisms and physical characteristics. Analysis of three-dimensional structure of these phenomena, including the structure of upstream flow, disturbances on the leeward side of the range, flow behavior above the ridges, was performed on the basis of observational data, MERRA reanalysis data and the results of mesoscale modeling using WRF-ARW model. The analysis identified characteristics common to all of the studied winds that allow us to classify them as a single phenomenon. Also the applicability of hydraulic and internal gravity wave theory, that are commonly used for downslope windstorms, was evaluated for studied winds. The hydraulic theory predicts the occurrence of hydraulic jump and the flow regime transition from subcritical to supercritical over the leeward slope, which leads to increased wind speed. On the other hand, the wave theory for some cases successfully explains these phenomena. It was shown that mesoscale pressure perturbations

  15. The blowflies of the Madeira Archipelago: species diversity, distribution and identification (Diptera, Calliphoridae s. l.)

    PubMed Central

    Prado e Castro, Catarina; Szpila, Krzysztof; Martínez-Sánchez, Anabel; Rego; Silva, Isamberto; Serrano, Artur R.M.; Boieiro, Mário

    2016-01-01

    Abstract Knowledge on the taxonomic diversity and distribution of blowflies from the Madeira Archipelago is updated. New and interesting findings are reported for poorly studied islands and islets of this archipelago, together with a brief analysis of the diversity of Macaronesian Calliphoridae s. l. Seven blowfly species were collected during this study, including the first records of Calliphora vicina Robineau-Desvoidy, 1830, Chrysomya albiceps (Wiedemann, 1819), Lucilia sericata (Meigen, 1826), Pollenia rudis (Fabricius, 1794) and Stomorhina lunata (Fabricius, 1805) from Porto Santo, and of Calliphora vicina, Lucilia sericata and Stomorhina lunata from Desertas Islands. The presence of Calliphora loewi Enderlein, 1903 in Madeira Laurisilva forest is discussed and its first instar larva is redescribed, revealing important differences in relation to its original description. An identification key to the adult Madeiran blowflies is provided for the first time. PMID:27917052

  16. Bald Eagles consume Emperor Geese during late-winter in the Aleutian Archipelago

    USGS Publications Warehouse

    Ricca, Mark A.; Anthony, Robert G.; Williams, Jeffrey C.

    2004-01-01

    Emperor Geese (Chen canagica) are a species of concern because their population has declined rapidly since the mid-1960s and continues to remain below management objectives (Petersen et al. 1994). Emperor Geese are restricted primarily to Alaska and exhibit an east-west migration pattern, whereby most birds begin breeding on the Yukon-Kuskokwim Delta by mid-May, stage on the Alaska Peninsula by late September, and migrate westward to winter in the Aleutian Archipelago from late November to mid-April (Eisenhauer and Kirkpatrick 1977, Petersen et al. 1994). Demographic and movement studies have been conducted on breeding grounds and stagmg areas (e.g., Schmutz et al. 1994, 1997); however, the winter ecology of Emperor Geese is poorly understood due in part to the extremely remote nature of the Aleutian Archipelago (Petersen et al. 1994). 

  17. Molecular studies on the colonization of the Madeiran archipelago by house mice.

    PubMed

    Gündüz, I; Auffray, J C; Britton-Davidian, J; Catalan, J; Ganem, G; Ramalhinho, M G; Mathias, M L; Searle, J B

    2001-08-01

    To study the colonization history of the house mouse (Mus musculus domesticus) on the Madeiran archipelago, complete mitochondrial D-loop sequences were obtained for 44 individuals from Madeira, Porto Santo and Ilhas Desertas. Altogether, 19 D-loop haplotypes were identified which formed part of a single clade in a phylogeny incorporating haplotypes from elsewhere in the range of M. m. domesticus, indicating that the Madeiras were colonized from a single source. Similarities between the sequences found in the Madeiras and those in Scandinavia and northern Germany suggest that northern Europe was the source area, and there is the intriguing possibility that the Vikings may have accidentally brought house mice to the archipelago. However, there is no record of Vikings visiting the Madeiras; on historical grounds, Portugal is the most likely source area for Madeiran mice and further molecular data from Portugal are needed to rule out that possibility.

  18. Modification of the Stratification and Velocity Profile within the Straits and Seas of the Indonesian Archipelago

    DTIC Science & Technology

    2012-09-30

    within the Straits and Seas of the Indonesian Archipelago Arnold L. Gordon Lamont-Doherty Earth Observatory 61 Route 9W Palisades, NY 10964...understanding of the energetic ocean physical processes within the northeastern Indonesian seas , as needed to improve our simulation of the regional...circulation and mixing patterns. OBJECTIVES The gap in understanding basic ocean physics of the Indonesian seas is most acute in the northeastern seas

  19. New insights on the petrology of submarine volcanics from the Western Pontine Archipelago (Tyrrhenian Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Conte, A. M.; Perinelli, C.; Bianchini, G.; Natali, C.; Martorelli, E.; Chiocci, F. L.

    2016-11-01

    The Pontine Islands form a volcanic archipelago in the Tyrrhenian Sea. It consists of two edifices, the islands of Ponza, Palmarola and Zannone and the islands of Ventotene and Santo Stefano, respectively. The Archipelago developed during two main volcanic cycles in the Plio-Pleistocene: 1) the Pliocene episode erupted subalkaline, silica-rich volcanic units, which constitute the dominant products in the western edifice (Ponza and Zannone Islands); 2) the Pleistocene episode erupted more alkaline products, represented by evolved rocks (trachytes to peralkaline rhyolites) in the islands of Ponza and Palmarola and by basic to intermediate rocks in the eastern edifice (Ventotene and Santo Stefano Islands). In this paper we present new geochemical and petrological data from submarine rock samples collected in two oceanographic cruises and a scuba diving survey. The main result is the recovery of relatively undifferentiated lithotypes that provide further insights on the magmatic spectrum existing in the Pontine Archipelago, allowing modelling of the whole suite of rocks by fractional crystallization processes. New major and trace element data and thermodynamic constrains (by the software PELE) indicate the existence of three distinct evolutionary trends corresponding to a HK calcalkaline series in the Pliocene, followed by a transitional and then by a shoshonite series in the Pleistocene. In particular, the transitional series, so far overlooked in the literature, is required in order to explain the genesis of several peralkaline felsic rocks recognized in the Archipelago. On the whole, the new geochemical data i) confirm the orogenic signature of the suites, ii) allow to rule out an anatectic origin for both subalkaline and peralkaline rhyolites and iii) indicate highly heterogeneous mantle sources, due to crustal components variously recycled in the mantle via subduction.

  20. Phylogeography of the prehensile-tailed skink Corucia zebrata on the Solomon Archipelago

    PubMed Central

    Hagen, Ingerid J; Donnellan, Stephen C; Bull, C Michael

    2012-01-01

    The biogeography of islands is often strongly influenced by prior geological events. Corucia zebrata (Squamata: Scincidae) is endemic to the geologically complex Solomon Archipelago in Northern Melanesia. We examined the level of divergence for different island populations of C. zebrata and discussed these patterns in light of Pleistocene land bridges, island isolation, and island age. Corucia zebrata was sampled from 14 locations across the Solomon Archipelago and sequenced at two mitochondrial genes (ND2 and ND4; 1697 bp in total) and four nuclear loci (rhodopsin, an unknown intron, AKAP9, and PTPN12). Measures of genetic divergence, analyses of genetic variation, and Bayesian phylogenetic inference were used and the data assessed in light of geological information. Populations of C. zebrata on separate islands were found to be genetically different from each other, with reciprocal monophyly on mitochondrial DNA. Populations on islands previously connected by Pleistocene land bridges were marginally less divergent from each other than from populations on other nearby but isolated islands. There are indications that C. zebrata has radiated across the eastern islands of the archipelago within the last 1–4 million years. Nuclear loci were not sufficiently informative to yield further information about the phylogeography of C. zebrata on the Solomon Archipelago. Analyses of the mitochondrial data suggest that dispersal between islands has been very limited and that there are barriers to gene flow within the major islands. Islands that have been isolated during the Pleistocene glacial cycles are somewhat divergent in their mitochondrial genotypes, however, isolation by distance (IBD) and recent colonization of isolated but geologically younger islands appear to have had stronger effects on the phylogeography of C. zebrata than the Pleistocene glacial cycles. This contrasts with patterns reported for avian taxa, and highlights the fact that biogeographic regions for

  1. Mid-recent human occupation and resource exploitation in the bismarck archipelago.

    PubMed

    White, J P; Downie, J E; Ambrose, W R

    1978-02-24

    Human settlement of the Bismarck Archipelago occurred by 6000 to 7500 years ago. Early inhabitants of New Ireland drew on widely dispersed stone sources, including obsidian from Talasea (New Britain), whereas those after about 3000 years ago used either stone from more local sources or obsidian from Lou Island (Admiralty Islands group) or Talasea. The dates and resource changes support a gradualist model of Melanesian settlement.

  2. Sharply increased mass loss from glaciers and ice caps in the Canadian Arctic Archipelago.

    PubMed

    Gardner, Alex S; Moholdt, Geir; Wouters, Bert; Wolken, Gabriel J; Burgess, David O; Sharp, Martin J; Cogley, J Graham; Braun, Carsten; Labine, Claude

    2011-05-19

    Mountain glaciers and ice caps are contributing significantly to present rates of sea level rise and will continue to do so over the next century and beyond. The Canadian Arctic Archipelago, located off the northwestern shore of Greenland, contains one-third of the global volume of land ice outside the ice sheets, but its contribution to sea-level change remains largely unknown. Here we show that the Canadian Arctic Archipelago has recently lost 61 ± 7 gigatonnes per year (Gt yr(-1)) of ice, contributing 0.17 ± 0.02 mm yr(-1) to sea-level rise. Our estimates are of regional mass changes for the ice caps and glaciers of the Canadian Arctic Archipelago referring to the years 2004 to 2009 and are based on three independent approaches: surface mass-budget modelling plus an estimate of ice discharge (SMB+D), repeat satellite laser altimetry (ICESat) and repeat satellite gravimetry (GRACE). All three approaches show consistent and large mass-loss estimates. Between the periods 2004-2006 and 2007-2009, the rate of mass loss sharply increased from 31 ± 8 Gt yr(-1) to 92 ± 12 Gt yr(-1) in direct response to warmer summer temperatures, to which rates of ice loss are highly sensitive (64 ± 14 Gt yr(-1) per 1 K increase). The duration of the study is too short to establish a long-term trend, but for 2007-2009, the increase in the rate of mass loss makes the Canadian Arctic Archipelago the single largest contributor to eustatic sea-level rise outside Greenland and Antarctica.

  3. Characterization and Modeling of the Philippine Archipelago Dynamics Using the ROMS 4DVAR Data Assimilation System

    DTIC Science & Technology

    2011-09-30

    assimilation (Moore et al., 2011a,b,c; Powell et al. 2008; Muccino et al., 2008; Di Lorenzo et al., 2007), ensemble prediction, adaptive sampling, circulation...ROMS adjoint and variational data assimilation) at Scripps Institute of Oceanography, E. Di Lorenzo (Southern California predictability) at Georgia...a Hindcast/Forecast Model for the Philippine Archipelago, oceanography, 20(1), 58-69, doi:10.5670/oceanog.2011.04. Di Lorenzo , E., A.M. Moore, H. G

  4. Rabies in an Arctic fox on the Svalbard archipelago, Norway, January 2011.

    PubMed

    Orpetveit, I; Ytrehus, B; Vikoren, T; Handeland, K; Mjos, A; Nissen, S; Blystad, H; Lund, A

    2011-02-17

    We report a case of rabies in an Arctic fox. In January 2011 a fox attacked dogs belonging to a meteorological station in the Svalbard archipelago, Norway. Rabies virus was detected in the fox's brain post-mortem. The dogs had been vaccinated against rabies and their antibody levels were protective. Post-exposure prophylaxis was administered to staff at the station. Rabies vaccination is recommended for inhabitants and visitors to the Arctic who may be in contact with wild animals.

  5. [Taxonomy and distribution of the hermatypic corals (Scleractinia) of the Revillagigedo Archipelago, Mexico].

    PubMed

    Ketchum, J T; Reyes Bonilla, H

    2001-01-01

    In spite of some recent detailed accounts about the scleractinian corals of the Archipiélago de Revillagigedo, taxonomic work on this fauna has been sparse. Consequently, solid taxonomic background is needed, especially to support further studies at community level. During five field trips (between 1990 and 1995) collections were made at different depths on three of the archipelago islands: Socorro, Clarión and San Benedicto. A total of 250 specimens were collected. Coral identifications were made using co-occurrence methods concomitant with their descriptions, diagnosis and illustrations from a number of publications, and with morphological analysis. Coral distributions were taken from literature. Twenty-two species of zooxanthellate scleractinian corals are described, with their local and world-wide geographic distribution, and each illustrated with macro and microphotographs. Keys to the genera and species of the archipelago are also included. Porites and Pocillopora exhibit the highest species richness with a great intraspecific variation, as well as a number of morphological convergences within and between species which form species complexes, and several new species and morphs. Clarion, the oldest and most isolated island of the archipelago, harbors a number of coral morphs that are probable new species. More than half of the species found at the Revillagigedos are distributed exclusively on oceanic islands of the eastern Pacific and close to one third exist only at this archipelago. The Revillagigedos have strong faunal similarities and share a number of endemics with Clipperton Atoll, all of which support the idea that these islands constitute a separate biogeographic subregion within the eastern Pacific. Lastly, the present document substantiates the hypothesis that the Revillagigedos are important stepping-stone islands for the migration of in-shore marine species from the Central to the eastern Pacific.

  6. On the issue of the Precambrian basement of the Arctic shelf

    NASA Astrophysics Data System (ADS)

    Vernikovsky, Valery A.; Korago, Evgeny A.; Proskurnin, Vasily F.; Sobolev, Nikolay N.

    2015-04-01

    Many researchers of the geological structures of the Russian Arctic concluded that the basements of the terranes composing the Arctic shelf and continental slopes have a Precambrian age. It is assumed that these terranes are actually fragments of the ancient Arctida paleocontinent [Zonenshain, Natapov, 1987] that broke up as a result of rifting and its separate plates and terranes either were overlain by continental margins sediments or included in the fold belts in the periphery of the ocean. In the western part of the Russian Arctic, a Grenvillian and Mesoproterozoic basement was demonstrated for Svalbard, Novaya Zemlya and Taimyr Peninsula, and at least a Neoproterozoic basement was established for structures in the basement of Severnaya Zemlya archipelago. In the eastern part of the Russian Arctic, such proofs were almost nonexistent. In recent years, new information was obtained concerning the continental nature and Precambrian age of the basement crust of the New Siberian Islands and De Long archipelagos as well as probably the Mendeleev Ridge. For the New Siberian Islands and De Long archipelagos, a whole series of geochronological evidence was obtained in addition to geological data (horizontally bedding Early Paleozoic passive continental margin sediments (Cambrian, Ordovician) at Bennett Island). In magmatic and tuffaceous-sedimentary rocks of Henrietta and Zhokhov islands we discovered zircons that had formed from magmatic crystallization in the Late Neoproterozoic. New U-Pb data for zircons from rocks of these islands do not contradict isotopic dating obtained earlier by other methods - Ar/Ar and Sm/Nd in different laboratories. Considering different closure temperatures for isotopic systems, these new results complement each other. On the islands of the eastern sector of the Russian Arctic, a Neoproterozoic complex of rocks is most certainly established in the basement of the mesozoides of Vrangel Island. Here were discovered metamorphosed volcanics

  7. Projected polar bear sea ice habitat in the Canadian Arctic Archipelago.

    PubMed

    Hamilton, Stephen G; Castro de la Guardia, Laura; Derocher, Andrew E; Sahanatien, Vicki; Tremblay, Bruno; Huard, David

    2014-01-01

    Sea ice across the Arctic is declining and altering physical characteristics of marine ecosystems. Polar bears (Ursus maritimus) have been identified as vulnerable to changes in sea ice conditions. We use sea ice projections for the Canadian Arctic Archipelago from 2006 - 2100 to gain insight into the conservation challenges for polar bears with respect to habitat loss using metrics developed from polar bear energetics modeling. Shifts away from multiyear ice to annual ice cover throughout the region, as well as lengthening ice-free periods, may become critical for polar bears before the end of the 21st century with projected warming. Each polar bear population in the Archipelago may undergo 2-5 months of ice-free conditions, where no such conditions exist presently. We identify spatially and temporally explicit ice-free periods that extend beyond what polar bears require for nutritional and reproductive demands. Under business-as-usual climate projections, polar bears may face starvation and reproductive failure across the entire Archipelago by the year 2100.

  8. Projected Polar Bear Sea Ice Habitat in the Canadian Arctic Archipelago

    PubMed Central

    Hamilton, Stephen G.; Castro de la Guardia, Laura; Derocher, Andrew E.; Sahanatien, Vicki; Tremblay, Bruno; Huard, David

    2014-01-01

    Background Sea ice across the Arctic is declining and altering physical characteristics of marine ecosystems. Polar bears (Ursus maritimus) have been identified as vulnerable to changes in sea ice conditions. We use sea ice projections for the Canadian Arctic Archipelago from 2006 – 2100 to gain insight into the conservation challenges for polar bears with respect to habitat loss using metrics developed from polar bear energetics modeling. Principal Findings Shifts away from multiyear ice to annual ice cover throughout the region, as well as lengthening ice-free periods, may become critical for polar bears before the end of the 21st century with projected warming. Each polar bear population in the Archipelago may undergo 2–5 months of ice-free conditions, where no such conditions exist presently. We identify spatially and temporally explicit ice-free periods that extend beyond what polar bears require for nutritional and reproductive demands. Conclusions/Significance Under business-as-usual climate projections, polar bears may face starvation and reproductive failure across the entire Archipelago by the year 2100. PMID:25426720

  9. Climate change influenced female population sizes through time across the Indonesian archipelago.

    PubMed

    Guillot, Elsa G; Tumonggor, Meryanne K; Lansing, J Stephen; Sudoyo, Herawati; Cox, Murray P

    2013-01-01

    Lying at the crossroads of Asia and the Pacific world, the Indonesian archipelago hosts one of the world's richest accumulations of cultural, linguistic, and genetic variation. While the role of human migration into and around the archipelago is now known in some detail, other aspects of Indonesia's complex history are less understood. Here, we focus on population size changes from the first settlement of Indonesia nearly 50 kya up to the historic era. We reconstructed the past effective population sizes of Indonesian women using mitochondrial DNA sequences from 2,104 individuals in 55 village communities on four islands spanning the Indonesian archipelago (Bali, Flores, Sumba, and Timor). We found little evidence for large fluctuations in effective population size. Most communities grew slowly during the late Pleistocene, peaked 15-20 kya, and subsequently declined slowly into the Holocene. This unexpected pattern may reflect population declines caused by the flooding of lowland hunter/gatherer habitat during sea-level rises following the last glacial maximum. Copyright © 2013 Wayne State University Press, Detroit, Michigan 48201-1309.

  10. Nest-density distribution patterns in a yellow-legged gull archipelago colony

    NASA Astrophysics Data System (ADS)

    Vidal, Eric; Roche, Philip; Bonnet, Véronique; Tatoni, Thierry

    2001-12-01

    The nest density distribution of yellow-legged gulls Larus cachinnans was investigated on the large Marseille archipelago colony (south-east France) which houses c. 18 000 breeding pairs. The study was performed at two investigation scales, including both mean nesting density on the nine study islands and density distribution within 171 sampling plots. The mean nesting density on each island was negatively correlated with island surface area and with the distance from the initial colony location (south-east end of the archipelago). No significant correlation was found with the other island parameters analysed (maximum elevation, shape index and distance from continent). A partial least squares regression performed between denstiy data from 171 500 m 2 sampling plots and environmental variables showed that the mostly explaining factors were island isolation and percentage of rocks in the plots (positive correlation), and distance of the island from the south-east end of the archipelago, island area, distance from plot to seaside and percentage of stone in the plots (negative correlation). Thus in our case, vegetation parameters (cover and height) were not influencial factors in nest density distribution.

  11. Natural concentrations and reference values for trace elements in soils of a tropical volcanic archipelago.

    PubMed

    Fabricio Neta, Adelazil de Brito; do Nascimento, Clístenes Williams Araújo; Biondi, Caroline Miranda; van Straaten, Peter; Bittar, Sheila Maria Bretas

    2016-10-25

    Fernando de Noronha is a small volcanic archipelago in the Southern Atlantic, some 350 km NE of the city of Natal in NE Brazil. These remote volcanic islands represent a largely pristine environment, distant from sources of anthropogenic contamination. This study was carried out to determine the natural concentrations of Ag, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, V and Zn in the A and B horizons of soils of Fernando de Noronha. The aims of the study were twofold: determine whether there is a relationship between the bedrock geology and soils and to establish quality reference values for soils from Fernando de Noronha. Soil samples were subjected to acid digestion by the USEPA method 3051A, and metals were determined by inductively coupled plasma emission spectrophotometry. The results showed that the trace element distribution largely reflects the geochemistry of the underlying volcanic rocks of the Remedios and Quixaba Formations. The results demonstrate that the concentrations of Ba, Cr, Zn, Ni and Cu from the soils of the volcanic Fernando de Noronha archipelago are higher than those found in soils from continental Brazil. However, concentrations of Ni, Cu and Co are lower in soils of the archipelago as compared to other volcanic islands throughout the world. The elevated trace element concentrations of the volcanic parent material of Fernando de Noronha soils seem to be the main factor governing the relatively high natural concentrations of trace elements.

  12. High prevalence of toxoplasmosis in free-range chicken of the Fernando de Noronha Archipelago, Brazil.

    PubMed

    Magalhães, Fernando Jorge Rodrigues; da Silva, José Givanildo; Ribeiro-Andrade, Müller; Pinheiro, José Wilton; Aparecido Mota, Rinaldo

    2016-07-01

    The present study aimed to determine the prevalence of toxoplasmosis in free-range chickens of the Fernando de Noronha Archipelago, Brazil and to identify risk factors associated with Toxoplasma gondii infection. Blood samples were collected from all the adult chickens raised in the Archipelago and screened by Indirect Fluorescent Antibody Test (430 samples, in total). Univariate analysis (Chi-square) and logistic regression were used to investigate the relationship between various variables possibly predictive of an increased likelihood of T. gondii infection. The overall prevalence of T. gondii infection in chickens of the Fernando de Noronha Archipelago was 88.4% (380/430; 84.6%-91.0%; 95% CI), ranging from 57.1% to 100.0% among the studied properties. The risk factors associated with T. gondii infection were the number of domestic cats in the properties (p=0.022), the presence of feral cats (p=0.006) and the presence of an open water source (p=0.046). Domestic and feral cats should be prevented from accessing the water and food supplied to chickens. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Patterns of diversification in islands: A comparative study across three gecko genera in the Socotra Archipelago.

    PubMed

    Garcia-Porta, Joan; Morales, Hernán E; Gómez-Díaz, Elena; Sindaco, Roberto; Carranza, Salvador

    2016-05-01

    In this study we used the complete fauna of geckos of the Socotra Archipelago to test whether the three gecko genera co-occurring in the islands (Pristurus, Hemidactylus and Haemodracon) produced similar outcomes of morphological and climatic diversification. To test this, we produced a time-calibrated tree of 346 geckos including all 16 endemic species of the archipelago and 26 potential close-relatives in the continent. Our dating estimates revealed that most of the diversity of geckos in the archipelago was the consequence of in situ diversification. However not all genera shared similar patterns of diversification. While in Hemidactylus and Haemodracon this involved great differences in body size and low levels of climatic diversification (mostly involving sympatric distributions), an opposite pattern appeared in Pristurus in which most of the diversification involved shifts in climatic envelopes (mostly involving allopatric and parapatric distributions) but almost no size differentiation. Consistently with this, Pristurus was the only genus in which rates of size diversification in islands were substantially lower than in the continent. This illustrates how different groups can greatly differ in their patterns of intra-island diversification and highlights the importance of taxon-dependent factors at determining different patterns of diversification in the same insular context.

  14. Tectonic development of the Indonesian archipelago and its bearing on the occurrence of hydrocarbons

    SciTech Connect

    Simanjuntak, T.O. )

    1994-07-01

    The present geological and tectonic configuration of the Indonesian archipelago may represent a typical triple junction plate convergence, which has developed since Neogene times due to the northward-moving Indo-Australian plate, the westward-moving Pacific plate, and the south-southeastward-moving Eurasian Craton. The occurrence of a number of microcontinents in eastern Indonesia makes the geology and tectonics of the region more complex. The archipelago is one of the most complicated regions from the plate tectonics point of view. The geological evolution of the Indonesian archipelago is recorded by the occurrence of both tectonic convergence and tectonic divergence. Various types of plate convergences include a Cordilleran type subduction, which has been reoccurring since Paleozoic until present times in western Indonesia; a Neogene Tethyan type collision in the Banda region; and a double-arc collision in northern Maluku, central Indonesia. Tectonic divergence, which was preceded by rifting due to thermal doming and magma rise in the northern margins of the Australian Craton and followed by the detachment and west-northwestward displacement of continental fragments in Mesozoic, gave rise to the development of the microcontinents in eastern Indonesia.

  15. The black flies (Diptera: Simuliidae) of the Lesser Sunda Archipelago, Indonesia.

    PubMed

    Takaoka, Hiroyuki; Sofian-Azirun, Mohd; Ya'cob, Zubaidah; Chen, Chee Dhang; Lau, Koon Weng; Low, Van Lun; Suana, I Wayan

    2017-05-01

    Surveys of pupae and larvae of black flies were carried out in Bali, Lombok, Sumbawa and Flores in the Lesser Sunda Archipelago, Indonesia, where 10 species were known. A total of 14 simuliid species including four new species and five new records of the genus Simulium were collected, bringing the number of species from the Lesser Sunda Archipelago to 19. They are classified into four subgenera: two in Nevermannia, nine in Gomphostilbia, seven in Simulium and one in Wallacellum. One of four new species, Simulium (Simulium) baliense, is described based on females, males, pupae and larvae from Bali and Lombok. This new species, which is placed in the Simulium striatum species-group of the subgenus Simulium, is closely related to S. (S.) argyrocinctum De Meijere from Java and Sumatra, but it is distinguished from the latter species by the smaller number of the male enlarged upper-eye facets and larval abdomen lacking dorsal pairs of conical protuberances. The distribution record of S. (S.) upikae Takaoka & Davies from Flores is corrected as that of S. (S.) eximium De Meijere. Some aberrant characters of the pupal gill filaments of S. (G.) atratum De Meijere, S. (G.) floresense Takaoka, Hadi & Sigit and S. (G.) sunapii Takaoka, Sofian-Azirun & Suana are illustrated. Characteristics of the fauna of black flies in this archipelago are briefly noted. Keys to all 19 species are provided for females, males, pupae and larvae.

  16. The causes of evolutionary radiations in archipelagoes: passerine birds in the Lesser Antilles.

    PubMed

    Ricklefs, Robert E; Bermingham, Eldredge

    2007-03-01

    To investigate why some lineages undergo evolutionary radiation, we compare the passerine avifaunas of the Hawaiian and Galapagos archipelagoes, which have supported well-known radiations of birds, with those of the Lesser Antilles, which have not. We focus on four steps required for the buildup of diversity through allopatric speciation and secondary sympatry: genetic divergence in isolation, persistence of island populations, recolonization of source islands, and ecological compatibility in secondary sympatry. Analysis of genetic divergence among island populations in the Lesser Antilles reveals evidence of both prolonged independent evolution and re-expansion of differentiated island populations through the archipelago but little evidence of secondary sympatry of divergent genetic lineages. Archipelagoes with high rates of colonization from continental or nearby large-island sources might fail to promote evolutionary radiations because colonists fill ecological space and constrain diversification through competition. However, morphological analysis demonstrated similar divergence between allopatric populations in species in Hawaii, Galapagos, and the Lesser Antilles, although the rate of divergence between secondarily sympatric species evidently is more rapid in Hawaii and the Galapagos. Alternatively, endemic buildup of diversity might be facilitated by the relative absence of pathogens in Hawaii and Galapagos that otherwise could prevent the secondary sympatry of populations owing to disease-mediated competition.

  17. Origins of Aleuts and the genetic structure of populations of the archipelago: molecular and archaeological perspectives.

    PubMed

    Crawford, Michael H; Rubicz, Rohina C; Zlojutro, Mark

    2010-12-01

    We summarize the results of a field and laboratory research program (1999-2006) in the Aleutian Islands on the origins of the inhabitants of the archipelago and the genetic structure of these populations. The Aleuts show closest genetic affinity to the contemporary Siberian Eskimos and Chukchi of Chukotka and differ significantly from the populations of Kamchatka (the terminus of the archipelago) and Alaskan Eskimos. Our findings support the hypothesis that the ancestors of the Aleuts crossed Beringia and expanded westerly into the islands approximately 9,000 years ago. The Monmonier algorithm indicates genetic discontinuity between contemporary Kamchatkan populations and western Aleut populations, suggesting that island hopping from Kamchatka into the western Aleutian Islands was highly unlikely. The primary determinant of the distribution of genes throughout the archipelago is geography. The most intimate relationship exists between the genetics (based on mtDNA sequences and intermatch/mismatch distances) and geographic distances (measured in kilometers). However, the Y-chromosome haplogroup frequencies are not significantly correlated with the geography of the Aleutian Islands. The underlying patterns of precontact genetic structure based on Y-chromosome markers of the Aleut populations is obscured because of the gene flow from Russian male colonizers and Scandinavian and English fishermen. We consider alternative theories about the peopling of the Americas from Siberia. In addition, we attempt a synthesis between archaeological and genetic data for the Aleutian Islands.

  18. Human genetic diversity in the Japanese Archipelago: dual structure and beyond.

    PubMed

    Jinam, Timothy A; Kanzawa-Kiriyama, Hideaki; Saitou, Naruya

    2015-01-01

    The Japanese Archipelago stretches approximately 3,000 kilometers from Hokkaido in the north to the Ryukyu Islands in the south, and has seen human activity since at least 30 thousand years ago (KYA). The Jomon period from 16 to 3 KYA is associated with cord-marked pottery and the people at that time, who were hunter-gatherers, occupied a range of locations across the Japanese Archipelago. The Yayoi period from 3 to 1.7 KYA saw the introduction of migrants from the Asian Continent who brought rice agriculture to the archipelago. The dual-structure model, which is based on craniofacial measurements, proposes that admixture between the Jomon and Yayoi people resulted in current-day Japanese. Subsequent genetic studies using uniparental and autosomal markers in current-day and ancient human samples are widely in support of the dual-structure model. These genetic data have also unveiled the uniqueness of the indigenous Ainu and Ryukyuan people while further demonstrating the genetic substructure within the Mainland Japanese.

  19. [Distribution characteristics of benthic algae in intertidal zone of Ma' an Archipelago of Zhejiang Province].

    PubMed

    Zhang, Shou-Yu; Liang, Jun; Wang, Zhen-Hua; Wang, Kai

    2008-10-01

    Based on the survey of benthic algae in the intertidal zone of Ma' an Archipelago from March to July 2007, the algal species composition, distribution, and temperature feature were studied. The dominant algal species in the study area were preliminarily analyzed by using similarity indices (S(c)) and index of relative importance (IRI(c)). A total of 31 species sampled in sublittoral area were identified, among which, 7 species of 5 genera belonged to Chlorophyta, 8 species of 5 genera belonged to Phaeophyta, and 16 species of 14 genera belonged to Rhodophyta. Topical and selective distribution species influenced by wave and tide were identified in the intertidal zone. Ulva pertusa and Sargassum thunbergii were found in all survey area. Rhodophyta was the dominant species, with the occurring frequency being up to 61.1%, and Chlorophyta showed quite uniformed horizontal distribution. In addition, 81% of sampled species were from low-tide zone, and some were extended from mid-tide zone to low-tide zone. The composition comparability between mid-tide and low-tide species was 0.47, and the convergence effect in mid-tide and low-tide zone was higher than that in high-tide and mid-tide zone. The sublittoral area of Ma' an Archipelago showed obvious vertical zoning character, with temperate species being absolute abundant, and the warm-water species dominant. The marine floral texture of Ma' an Archipelago belongs to warm temperate-subtropical transitional marine flora.

  20. Evolution at a different pace: distinctive phylogenetic patterns of cone snails from two ancient oceanic archipelagos.

    PubMed

    Cunha, Regina L; Lima, Fernando P; Tenorio, Manuel J; Ramos, Ana A; Castilho, Rita; Williams, Suzanne T

    2014-11-01

    Ancient oceanic archipelagos of similar geological age are expected to accrue comparable numbers of endemic lineages with identical life history strategies, especially if the islands exhibit analogous habitats. We tested this hypothesis using marine snails of the genus Conus from the Atlantic archipelagos of Cape Verde and Canary Islands. Together with Azores and Madeira, these archipelagos comprise the Macaronesia biogeographic region and differ remarkably in the diversity of this group. More than 50 endemic Conus species have been described from Cape Verde, whereas prior to this study, only two nonendemic species, including a putative species complex, were thought to occur in the Canary Islands. We combined molecular phylogenetic data and geometric morphometrics with bathymetric and paleoclimatic reconstructions to understand the contrasting diversification patterns found in these regions. Our results suggest that species diversity is even lower than previously thought in the Canary Islands, with the putative species complex corresponding to a single species, Conus guanche. One explanation for the enormous disparity in Conus diversity is that the amount of available habitat may differ, or may have differed in the past due to eustatic (global) sea level changes. Historical bathymetric data, however, indicated that sea level fluctuations since the Miocene have had a similar impact on the available habitat area in both Cape Verde and Canary archipelagos and therefore do not explain this disparity. We suggest that recurrent gene flow between the Canary Islands and West Africa, habitat losses due to intense volcanic activity in combination with unsuccessful colonization of new Conus species from more diverse regions, were all determinant in shaping diversity patterns within the Canarian archipelago. Worldwide Conus species diversity follows the well-established pattern of latitudinal increase of species richness from the poles towards the tropics. However, the eastern

  1. Modeling nutrient retention in the coastal zone of an eutrophic sea - a model study in the Stockholm Archipelago, Sweden

    NASA Astrophysics Data System (ADS)

    Almroth-Rosell, Elin; Edman, Moa; Eilola, Kari; Meier, Markus; Sahlberg, Jörgen

    2016-04-01

    This study shows that the Stockholm archipelago works as a filter for nutrients that enters the coastal zone from land. The filter capacity is high, but not effective enough to take care of all the nutrients that the system receives. At least 65 % and 72 % of the phosphorus (P) and nitrogen (N), respectively, is retained. The multi-basin one dimensional Swedish Coastal zone Model (SCM) that was used is based on the Swedish Coastal and Ocean Biogeochemical model (SCOBI) coupled to the equation solver PROgram for Boundary layers in the Environment (PROBE). An evaluation of model results showed that the nutrient, salinity and temperature dynamics in the SCM model are of good quality. To analyse the results the Stockholm archipelago was divided into three sub-areas: the inner, the intermediate and the outer archipelago. The analysis showed that the highest total amounts of P and N are retained in the outer archipelago where the surface area is largest. The area weighted retention of P and N, however, is highest in the smaller inner archipelago and decreases towards the open sea. A major part of the retention is permanent. For P sediment burial is the only permanent retention mechanism, but for N almost 92 % of the permanent retention is caused by benthic denitrification, less than 8 % by burial, while pelagic denitrification is below 1%. A reduction of the land load of nutrients (P reduced with 13 % and N with 20%) resulted in increased retention capacity of N and P and lowered the transport of N out from the archipelago. About 15 years after the reduction P is imported into the archipelago instead of being exported.

  2. Phylogeographic analyses of submesophotic snappers Etelis coruscans and Etelis "marshi" (family Lutjanidae) reveal concordant genetic structure across the Hawaiian Archipelago.

    PubMed

    Andrews, Kimberly R; Moriwake, Virginia N; Wilcox, Christie; Grau, E Gordon; Kelley, Christopher; Pyle, Richard L; Bowen, Brian W

    2014-01-01

    The Hawaiian Archipelago has become a natural laboratory for understanding genetic connectivity in marine organisms as a result of the large number of population genetics studies that have been conducted across this island chain for a wide taxonomic range of organisms. However, population genetic studies have been conducted for only two species occurring in the mesophotic or submesophotic zones (30+m) in this archipelago. To gain a greater understanding of genetic connectivity in these deepwater habitats, we investigated the genetic structure of two submesophotic fish species (occurring ∼200-360 m) in this archipelago. We surveyed 16 locations across the archipelago for submesophotic snappers Etelis coruscans (N = 787) and E. "marshi" (formerly E. carbunculus; N = 770) with 436-490 bp of mtDNA cytochrome b and 10-11 microsatellite loci. Phylogeographic analyses reveal no geographic structuring of mtDNA lineages and recent coalescence times that are typical of shallow reef fauna. Population genetic analyses reveal no overall structure across most of the archipelago, a pattern also typical of dispersive shallow fishes. However some sites in the mid-archipelago (Raita Bank to French Frigate Shoals) had significant population differentiation. This pattern of no structure between ends of the Hawaiian range, and significant structure in the middle, was previously observed in a submesophotic snapper (Pristipomoides filamentosus) and a submesophotic grouper (Hyporthodus quernus). Three of these four species also have elevated genetic diversity in the mid-archipelago. Biophysical larval dispersal models from previous studies indicate that this elevated diversity may result from larval supplement from Johnston Atoll, ∼800 km southwest of Hawaii. In this case the boundaries of stocks for fishery management cannot be defined simply in terms of geography, and fishery management in Hawaii may need to incorporate external larval supply into management plans.

  3. Toward a Theory of Island Pedogeography: Testing the driving forces for pedological assemblages in archipelagos of different origins

    NASA Astrophysics Data System (ADS)

    Ibáñez, Juan-José; Effland, William R.

    2011-12-01

    The Theory of Island Biogeography has been based on biodiversity studies and used as a powerful predictive tool. Currently pedogeography does not have a similar theoretical construct. Although island biodiversity and biological assemblages have been topics of widespread interest in biogeography, ecology and conservation biology, soil scientists have conducted few studies of pedodiversity and pedological assemblages in archipelagos. Several studies have demonstrated that pedodiversity and biodiversity patterns have striking similarities in very disparate environments and at different scales, thus it is possible to test for a similar construct of island pedogeography. We analyze similarities and differences in the pedosphere for three archipelagos with different origins: (i) oceanic-intra-plate chains islands (Hawaiian Islands), (ii) oceanic-intra-plate cluster islands (Canary Islands), (iii) non-marine land-bridge islands with volcanism associated with plate boundary conditions (Aegean Islands) and (iv) as a comparison, islands in a nonplate boundary setting (the British Isles). In the Canary Islands, we also compiled selected biological, physiographical, geological and climatic data for further analysis of pedodiversity, climatic diversity, geodiversity and biodiversity. Our pedogeographic analysis of the three archipelagos indicates archipelagos of varying origins contain different soil assemblages with plate tectonics as the main driving force. The similarities between pedodiversity and biodiversity are more remarkable than the differences. We tested the hypothesis that soil taxa distributions on island chains can be modelled as a power function similar to the species-area relationship (SAR) proposed by McArthur and Wilson for archipelagos. The SAR functional relationship has been widely corroborated in other biodiversity studies. The same patterns were obtained for pedodiversity and biodiversity in the British Isles, and after that in the Aegean Archipelago. In

  4. The effects of archipelago spatial structure on island diversity and endemism: predictions from a spatially-structured neutral model.

    PubMed

    Gascuel, Fanny; Laroche, Fabien; Bonnet-Lebrun, Anne-Sophie; Rodrigues, Ana S L

    2016-11-01

    Islands are particularly suited to testing hypotheses about the ecological and evolutionary mechanisms underpinning community assembly. Yet the complex spatial arrangements of real island systems have received little attention from both empirical studies and theoretical models. Here, we investigate the extent to which the spatial structure of archipelagos affects species diversity and endemism. We start by proposing a new spatially structured neutral model that explicitly considers archipelago structure, and then investigate its predictions under a diversity of scenarios. Our results suggest that considering the spatial structure of archipelagos is crucial to understanding their diversity and endemism, with structured island systems acting both as "museums" and "cradles" of biodiversity. These dynamics of diversification may change the traditionally expected pattern of decrease in species richness with distance from the mainland, even potentially leading to increasing patterns for taxa with high speciation rates in archipelagos off species-poor continental areas. Our results also predict that, within spatially structured archipelagos, metapopulation dynamics and evolutionary processes can generate higher diversity on islands more centrally placed than at the periphery. We derive from our results a set of theoretical predictions, potentially testable with empirical data. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  5. Spatial features of glacier changes in the Barents-Kara Sector

    NASA Astrophysics Data System (ADS)

    Sharov, A. I.; Schöner, W.; Pail, R.

    2009-04-01

    In the 1950s, the total area of glaciers occupying separate islands and archipelagos of the Barents and Kara seas exceeded 92,300 km² (Atlas of the Arctic 1985). The overall glacier volume reached 20,140 km³ and the average ice thickness was given as 218 m. Our recent remote sensing studies and mass-balance estimates using spaceborne ASTER and LANDSAT imagery, ERS and JERS radar interferometric mosaics, and ICESat altimetry data revealed that, in the 2000s, the areal extent and volume of Barents-Kara glaciation amounted to 86,200±200 km² and 19,330±20 km³, respectively. The annual loss of land ice influenced by severe climate change in longitudinal direction was determined at approx. 8 km³/a in Svalbard, 4 km³/a both in the Franz Josef Land and Novaya Zemlya archipelagos, and less than 0.3 km³/a in Severnaya Zemlya over the past 50 years. The average ice thickness of remaining glaciation increased to 224 m. This fact was explained by rapid disintegration of thinner glacier margins and essential accumulation of snow at higher glacier elevations. Both effects were clearly visible in the series of satellite image maps of glacier elevation changes generated within the framework of the INTEGRAL, SMARAGD and ICEAGE research projects. These maps can be accessed at http://joanneum.dib.at/integral or smaragd (cd results). The largest negative elevation changes were typically detected in the seaward basins of fast-flowing outlet glaciers, both at their fronts and tops. Ablation processes were stronger manifested on southern slopes of ice caps, while the accumulation of snow was generally higher on northern slopes so that main ice divides "shifted" to the north. The largest positive elevation changes (about 100 m) were found in the central part of the study region in the accumulation areas of the biggest ice caps, such as Northern Ice Cap in Novaya Zemlya, Tyndall and Windy ice domes in Franz Josef Land, and Kvitoyjokulen at Kvitøya. The sides of these glaciers

  6. Elemental composition and Its seasonal variation of bulk aerosols collected at the Okinawa archipelago, Japan

    NASA Astrophysics Data System (ADS)

    Itoh, Akihide; Oshiro, Seiji; Azechi, Sotaro; Handa, Daishi; Arakaki, Takemitsu

    2010-05-01

    Okinawa is situated approximately 1500 km south of Tokyo, Japan, 2000 km south east of Beijing, China, and 1000 km south of South Korea. Its location in Asia is well suited for studying long-range transport of air pollutions in East Asia, because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. In the present study, elemental composition and its seasonal variation of bulk aerosols collected at the Okinawa archipelago was investigated by a X-ray fluorescence spectrometric method (XRF). From these results, chemical properties of aerosols transported to Okinawa archipelago and long-range transport of metal pollutions were discussed. We continuously collected bulk aerosols for 7 days at a time during 2008 - 2009. The samplings were performed by using the same type of high volume air sampler at Cape Hedo Atmospheric Aerosol Monitoring Station (CHAAMS, Okinawa island), Kume island (ca. 160 km south-west of CHAAMS), and Minami-Daitou island (ca. 320 km south-east of CHAAMS), respectively. XRF allows us to analyze bulk aerosols rapidly without any pretreatment. However, it is very difficult to determine trace metals in aerosol samples accurately. The concentration ratios to Al for 15-20 elements, whose accuracy was evaluated using standard reference materials (NIES No.28) and measuring by an inductively coupled plasma mass spectrometry (ICP-MS) after acid-digestion, were obtained by XRF. From seasonal variations obtained, the concentration rations to Al for Pb and As in aerosol particles were clearly higher in winter than in summer. These results suggest that North-west wind blown in winter would transport pollutant aerosols to Okinawa archipelago from East Asia.

  7. The lost Adventure Archipelago (Sicilian Channel, Mediterranean Sea): Morpho-bathymetry and Late Quaternary palaeogeographic evolution

    NASA Astrophysics Data System (ADS)

    Civile, Dario; Lodolo, Emanuele; Zecchin, Massimo; Ben-Avraham, Zvi; Baradello, Luca; Accettella, Daniela; Cova, Andrea; Caffau, Mauro

    2015-02-01

    The rise in sea level following the Last Glacial Maximum (LGM) radically altered pre-existing geography, pushing back the former shorelines. The effect of this eustatic change was particularly intense and dramatic in flat lands and shelves, such as the Sicilian Channel. High-resolution bathymetric maps and Chirp seismic profiles analyzed in this study show that the Sicilian Channel, now lying at depths rarely exceeding 150 m, has emerged several times during its geological history. The last emergence was during the Early Holocene, when kilometre-sized islands punctuated the north-western sector of the Sicilian Channel, the Adventure Plateau, forming a broad archipelago. Many of these islands, now located in water ranging in depth from - 10 to - 40 m, are composed of highly deformed Neogene sedimentary rocks (Talbot, Ante-Talbot, Nereo, and Pantelleria Vecchia banks), while others represent submarine Pleistocene volcanic edifices (Galatea, Anfitrite and Tetide banks). Sedimentary cover in all of these banks is virtually absent. High-resolution seismic profiles allowed the identification of post-LGM morphological markers associated with the marine transgression, some of which are characterized by melt water-pulses, as demonstrated by the presence of specific and distinct erosional features. Combining swath bathymetric data with the seismic profiles, we have generated two palaeogeographic maps of the former Adventure Archipelago at two specific time frames: (1) at the end of the Younger Dryas stadial (11,500 yr B.P., corresponding to a former sea level of - 60 m), and (2) at the end of the melt-water pulse 1B (11,200 yr B.P., corresponding to a former sea level of - 42 m). Maps clearly show that in just 300 years the geography of the archipelago has changed dramatically, so much so that some islands have disappeared and some have decreased by more than 80% of their pre-Younger Dryas size.

  8. Life on the Edge: Holocene Tephra Stratigraphy of Tanginak Anchorage, Sitkalidak Island, Kodiak Archipelago, Alaska

    NASA Astrophysics Data System (ADS)

    Mahrt, E.; Bourgeois, J.; Fitzhugh, J. B.

    2004-12-01

    Geologic hazards associated with volcanism in the North Pacific have profound if usually temporary effects on the environment and human populations. Ash falls associated with these events are often preserved across large areas providing time specific markers. In the past century, volcanic activity and its effects in the North Pacific have been recorded, but much of the Holocene volcanic record in the Alaskan region is still being investigated. The Kodiak Archipelago, while not volcanic itself, is located near both Aleutian and Alaskan peninsula volcanoes. However, little has been published about the Holocene tephrochronology of the Kodiak region. This study focuses on the area around Tanginak Spring Site (KOD481). Located on Sitkalidak Island it is the earliest known human occupation in the Kodiak archipelago. We are documenting Holocene environmental changes on Sitkalidak Island and relating these changes to the archaeological record. As part of this work, we will establish a local tephrochronology using stratigraphy and geochemistry which will allow us to better correlate sedimentary changes across large areas as well as study human interaction with ashfall events. Herein we report a preliminary tephrochronology in peat excavations on Sitkalidak Island dating back to the earliest Holocene. Dates are radiocarbon years BP on peat directly below tephra. Marker tephra present in our reference sections are Katmai 1912, light gray (historic?), medium gray (3370), medium gray (3720), beige 1 (4340), apricot (5390), beige 3 (6790), black (9280), and white (11,520). Geochemical and petrographic analysis will help to determine with which volcanic events these tephra are associated. Establishing a local tephrochronology is important not only for local correlation but also to ascertain the tephra stratigraphy of the Kodiak Archipelago and beyond. The frequency of tephra in Tanginak Anchorage sections suggests that tephra will be a very useful stratigraphic tool in this

  9. Multiple, independent colonizations of the Hawaiian Archipelago by the family Dolichopodidae (Diptera)

    PubMed Central

    Goodman, Kari Roesch; Evenhuis, Neal; Bartošová-Sojková, Pavla

    2016-01-01

    The family Dolichopodidae forms two of the four largest evolutionary radiations in the Hawaiian Islands across all flies: Campsicnemus (183 spp) and the Eurynogaster complex (66 spp). They also include a small radiation of Conchopus (6 spp). A handful of other dolichopodid species are native to the islands in singleton lineages or small radiations. This study provides a phylogenetic perspective on the colonization history of the dolichopodid fauna in the islands. We generated a multi-gene data set including representatives from 11 of the 14 endemic Hawaiian dolichopodid genera to examine the history of colonization to the islands, and analyzed it using Bayesian and maximum likelihood phylogenetic methods. We used a subset of the data that included Conchopus and the eight genera comprising the Eurynogaster complex to estimate the first phylogenetic hypothesis for these endemic groups, then used Beast to estimate their age of arrival to the archipelago. The Eurynogaster complex, Campsicnemus and Conchopus are clearly the result of independent colonizations. The results strongly support the Eurynogaster complex as a monophyletic group, and also supports the monophyly of 4 of the 8 described genera within the complex (Adachia, Arciellia, Uropachys and Eurynogaster). Members of the family Dolichopodidae have been dispersing over vast distances to colonize the Hawaiian Archipelago for millions of years, leading to multiple independent evolutionary diversification events. The Eurynogaster complex arrived in the Hawaiian Archipelago 11.8 Ma, well before the arrival of Campsicnemus (4.5 Ma), and the even more recent Conchopus (1.8 Ma). Data presented here demonstrate that the Hawaiian Dolichopodidae both disperse and diversify easily, a rare combination that lays the groundwork for field studies on the reproductive isolating mechanisms and ecological partitioning of this group. PMID:27896033

  10. Plant speciation in continental island floras as exemplified by Nigella in the Aegean Archipelago.

    PubMed

    Comes, Hans Peter; Tribsch, Andreas; Bittkau, Christiane

    2008-09-27

    Continental shelf island systems, created by rising sea levels, provide a premier setting for studying the effects of geographical isolation on non-adaptive radiation and allopatric speciation brought about by genetic drift. The Aegean Archipelago forms a highly fragmented complex of mostly continental shelf islands that have become disconnected from each other and the mainland in relatively recent geological times (ca <5.2 Ma). These ecologically fairly homogenous islands thus provide a suitable biogeographic context for assessing the relative influences of past range fragmentation, colonization, gene flow and drift on taxon diversification. Indeed, recent molecular biogeographic studies on the Aegean Nigella arvensis complex, combining phylogenetic, phylogeographic and population level approaches, exemplify the importance of allopatry and genetic drift coupled with restricted gene flow in driving plant speciation in this continental archipelago at different temporal and spatial scales. While the recent (Late Pleistocene) radiation of Aegean Nigella, as well as possible instances of incipient speciation (in the Cyclades), is shown to be strongly conditioned by (palaeo)geographic factors (including changes in sea level), shifts in breeding system (selfing) and associated isolating mechanisms have also contributed to this radiation. By contrast, founder event speciation has probably played only a minor role, perhaps reflecting a migratory situation typical for continental archipelagos characterized by niche pre-emption because of a long established resident flora. Overall, surveys of neutral molecular markers in Aegean Nigella have so far revealed population genetic processes that conform remarkably well to predictions raised by genetic drift theory. The challenge is now to gain more direct insights into the relative importance of the role of genetic drift, as opposed to natural selection, in the phenotypic and reproductive divergence among these Aegean plant

  11. Biogeographic discordance of molecular phylogenetic and phenotypic variation in a continental archipelago radiation of land snails

    PubMed Central

    2014-01-01

    Background In island archipelagos, where islands have experienced repeated periods of fragmentation and connection through cyclic changes in sea level, complex among-island distributions might reflect historical distributional changes or local evolution. We test the relative importance of these mechanisms in an endemic radiation of Rhagada land snails in the Dampier Archipelago, a continental archipelago off the coast of Western Australia, where ten morphospecies have complex, overlapping distributions. Results We obtained partial mtDNA sequence (COI) for 1015 snails collected from 213 locations across 30 Islands, and used Bayesian phylogenetic analysis and Analysis of Molecular Variance (AMOVA) to determine whether geography or the morphological taxonomy best explains the pattern of molecular evolution. Rather than forming distinct monophyletic groups, as would be expected if they had single, independent origins, all of the widely distributed morphospecies were polyphyletic, distributed among several well-supported clades, each of which included several morphospecies. Each mitochondrial clade had a clear, cohesive geographic distribution, together forming a series of parapatric replacements separated by narrow contact zones. AMOVA revealed further incongruence between mtDNA diversity and morphological variation within clades, as the taxonomic hypothesis always explained a low or non-significant proportion of the molecular variation. In contrast, the pattern of mtDNA evolution closely reflected contemporary and historical marine barriers. Conclusions Despite opportunities for distributional changes during periods when the islands were connected, there is no evidence that dispersal has contributed to the geographic variation of shell form at the broad scale. Based on an estimate of dispersal made previously for Rhagada, we conclude that the periods of connection have been too short in duration to allow for extensive overland dispersal or deep mitochondrial

  12. Genetic Structure of the Endangered Plant Neolitsea sericea (Lauraceae) from the Zhoushan Archipelago Using RAPD Markers

    PubMed Central

    WANG, ZHONG-SHENG; AN, SHU-QING; LIU, HONG; LENG, XIN; ZHENG, JIAN-WEI; LIU, YU-HONG

    2004-01-01

    • Background and Aims The Zhoushan archipelago is the largest archipelago in China. It separated from the mainland about 9000 years ago due to rising sea levels and climate change. Because of the long-term influences of human activities, the original forest vegetation on the large islands has been badly damaged and its plant diversity reduced. • Methods Levels and patterns of genetic diversity in 114 individuals from six natural populations and four cultivated populations of the insular endangered plant Neolitsea sericea (Lauraceae) on the Zhoushan archipelago were assessed using random amplified polymorphic DNA (RAPD) markers. • Key Results A total of 99 discernible loci were obtained for all populations using ten primers, 50·5 % of which were polymorphic [percentage of polymorphic bands (PPB) = 50·5 %]. Despite being a woody, long-lived, perennial, outcrossing and insect-pollinated plant, N. sericea exhibited low levels of genetic variation. The cultivated populations (PPB = 18·9 %, HE = 0·060, S = 0·092) were genetically less diverse than the natural populations (PPB = 23·1 %, HE = 0·082, S = 0·123). Based on analysis of molecular variance, a high degree of among-population differentiation was revealed for both natural (0·387) and cultivated populations (0·598). • Conclusions Removal of plants from the wild for horticulture purposes has eroded the level of genetic variation of N. sericea. Low levels of genetic diversity and a high degree of population differentiation indicate that management strategies should include conservation of natural habitats occupied by all six wild populations, and sampling of germplasm resources from multiple seed sources. PMID:15546928

  13. Genetic structure of the endangered plant Neolitsea sericea (Lauraceae) from the Zhoushan archipelago using RAPD markers.

    PubMed

    Wang, Zhong-Sheng; An, Shu-Qing; Liu, Hong; Leng, Xin; Zheng, Jian-Wei; Liu, Yu-Hong

    2005-01-01

    The Zhoushan archipelago is the largest archipelago in China. It separated from the mainland about 9000 years ago due to rising sea levels and climate change. Because of the long-term influences of human activities, the original forest vegetation on the large islands has been badly damaged and its plant diversity reduced. Levels and patterns of genetic diversity in 114 individuals from six natural populations and four cultivated populations of the insular endangered plant Neolitsea sericea (Lauraceae) on the Zhoushan archipelago were assessed using random amplified polymorphic DNA (RAPD) markers. A total of 99 discernible loci were obtained for all populations using ten primers, 50.5 % of which were polymorphic [percentage of polymorphic bands (PPB)=50.5 %]. Despite being a woody, long-lived, perennial, outcrossing and insect-pollinated plant, N. sericea exhibited low levels of genetic variation. The cultivated populations (PPB=18.9 %, HE=0.060, S=0.092) were genetically less diverse than the natural populations (PPB=23.1 %, HE=0.082, S=0.123). Based on analysis of molecular variance, a high degree of among-population differentiation was revealed for both natural (0.387) and cultivated populations (0.598). Removal of plants from the wild for horticulture purposes has eroded the level of genetic variation of N. sericea. Low levels of genetic diversity and a high degree of population differentiation indicate that management strategies should include conservation of natural habitats occupied by all six wild populations, and sampling of germplasm resources from multiple seed sources.

  14. Seismicity Pattern Changes before the M = 4.8 Aeolian Archipelago (Italy) Earthquake of August 16, 2010

    PubMed Central

    2014-01-01

    We investigated the seismicity patterns associated with an M = 4.8 earthquake recorded in the Aeolian Archipelago on 16, August, 2010, by means of the region-time-length (RTL) algorithm. This earthquake triggered landslides at Lipari; a rock fall on the flanks of the Vulcano, Lipari, and Salina islands, and some damages to the village of Lipari. The RTL algorithm is widely used for investigating precursory seismicity changes before large and moderate earthquakes. We examined both the spatial and temporal characteristics of seismicity changes in the Aeolian Archipelago region before the M = 4.8 earthquake. The results obtained reveal 6-7 months of seismic quiescence which started about 15 months before the earthquake. The spatial distribution shows an extensive area characterized by seismic quiescence that suggests a relationship between quiescence and the Aeolian Archipelago regional tectonics. PMID:24511288

  15. Seismicity pattern changes before the M = 4.8 Aeolian Archipelago (Italy) earthquake of August 16, 2010.

    PubMed

    Gambino, Salvatore; Laudani, Antonino; Mangiagli, Salvatore

    2014-01-01

    We investigated the seismicity patterns associated with an M = 4.8 earthquake recorded in the Aeolian Archipelago on 16, August, 2010, by means of the region-time-length (RTL) algorithm. This earthquake triggered landslides at Lipari; a rock fall on the flanks of the Vulcano, Lipari, and Salina islands, and some damages to the village of Lipari. The RTL algorithm is widely used for investigating precursory seismicity changes before large and moderate earthquakes. We examined both the spatial and temporal characteristics of seismicity changes in the Aeolian Archipelago region before the M = 4.8 earthquake. The results obtained reveal 6-7 months of seismic quiescence which started about 15 months before the earthquake. The spatial distribution shows an extensive area characterized by seismic quiescence that suggests a relationship between quiescence and the Aeolian Archipelago regional tectonics.

  16. Modification of the Stratification and Velocity Profile Within the Straits and Seas of the Indonesian Archipelago

    DTIC Science & Technology

    2012-10-10

    sponges , crustaceans, mollusks and fish on this planet. There are over 600 types of coral, 3000 species offish, sea turtles, whales, and dolphins. It is...lö Ot-fa&eß A,i(% FINAL REPORT Modification of the stratification and velocity profile within the straits and seas of the Indonesian Archipelago...ldeo.columbia.edu Award Number: N00014-10-1-0317 The gap in understanding basic ocean physics of the Indonesian seas is most acute in the northeastern seas

  17. Aerosol chemistry above an extended archipelago of the eastern Mediterranean basin during strong northern winds

    NASA Astrophysics Data System (ADS)

    Athanasopoulou, E.; Protonotariou, A. P.; Bossioli, E.; Dandou, A.; Tombrou, M.; Allan, J. D.; Coe, H.; Mihalopoulos, N.; Kalogiros, J.; Bacak, A.; Sciare, J.; Biskos, G.

    2015-07-01

    Detailed aerosol chemical predictions by a comprehensive model system (i.e. PMCAMx, WRF, GEOS-CHEM), along with airborne and ground-based observations, are presented and analysed over a wide domain covering the Aegean Archipelago. The studied period is 10 successive days in 2011, characterized by strong northern winds, which is the most frequently prevailing synoptic pattern during summer. The submicron aerosol load in the lower troposphere above the archipelago is homogenously enriched in sulfate (average modelled and measured submicron sulfate of 5.5 and 5.8 μg m-3, respectively), followed by organics (2.3 and 4.4 μg m-3) and ammonium (1.5 and 1.7 μg m-3). Aerosol concentrations smoothly decline aloft, reaching lower values (< 1 μg m-3) above 4.2 km altitude. The evaluation criteria rate the model results for sulfate, ammonium, chloride, elemental carbon, organic carbon and total PM10 mass concentrations as "good", indicating a satisfactory representation of the aerosol chemistry and precursors. Higher model discrepancies are confined to the highest (e.g. peak sulfate values) and lowest ends (e.g. nitrate) of the airborne aerosol mass size distribution, as well as in airborne organic aerosol concentrations (model underestimation ca. 50 %). The latter is most likely related to the intense fire activity at the eastern Balkan area and the Black Sea coastline, which is not represented in the current model application. The investigation of the effect of local variables on model performance revealed that the best agreement between predictions and observations occurs during high winds from the northeast, as well as for the area confined above the archipelago and up to 2.2 km altitude. The atmospheric ageing of biogenic particles is suggested to be activated in the aerosol chemistry module, when treating organics in a sufficient nitrogen and sulfate-rich environment, such as that over the Aegean basin. More than 70 % of the predicted aerosol mass over the Aegean

  18. An Integrated Bathymetric and Topographic Digital Terrain Model of the Canadian Arctic Archipelago

    NASA Astrophysics Data System (ADS)

    Alm, G.; Macnab, R.; Jakobsson, M.; Kleman, J.; McCracken, M.

    2002-12-01

    Currently, the International Bathymetric Chart of the Arctic Ocean (IBCAO) [Jakobsson et al. 2000], contains the most up-to-date digital bathymetric model of the entire Canadian Arctic Archipelago. IBCAO is a seamless bathymetric/topographic Digital Terrain Model (DTM) that incorporates three primary data sets: all available bathymetric data at the time of compilation; the US Geological Survey GTOPO30 topographic data; and the World Vector Shoreline for coastline representation. The horizontal grid cell size is 2.5 x 2.5 km on a Polar Stereographic projection, which is adequate for regional visualization and analysis, but which may not be sufficient for certain geoscientific and oceanographic applications. However, the database that was constructed during the IBCAO project holds bathymetric data of a high quality throughout most of the Canadian Arctic Archipelago, justifying a compilation resolution that is better than 2.5 x 2.5 km. This data is primarily from historical hydrographic surveys that were carried out by the Canadian Hydrographic Survey (CHS). The construction of a higher resolution bathymetry/topography DTM of the Canadian Arctic Archipelago (complete with an error estimation of interpolated grid cells) requires a consideration of historical metadata which contains detailed descriptions of horizontal and vertical datums, positioning systems, and the depth sounding systems that were deployed during individual surveys. A significant portion of this metadata does not exist in digital form; it was not available during the IBCAO compilation, although due to the relatively low resolution of the original DTM (2.5 x 2.5 km), its absence was considered a lesser problem. We have performed "data detective" work and have extracted some of the more crucial metadata from CHS archives and are thus able to present a preliminary version of a seamless Digital Terrain Model of the Canadian Arctic Archipelago. This represents a significant improvement over the original

  19. Polynya Formation, Location, Sea Level History and Human Settlement in the Canadian Arctic Archipelago

    NASA Astrophysics Data System (ADS)

    Schledermann, P.; Murray, M. S.; Hannah, C. G.

    2014-12-01

    In this paper we illustrate the relationship between polynya location and archaeological site distribution in the Canadian Arctic archipelago. Polynyas in this region may be tidally driven or latent heat polynyas and Holocene-ere human settlement in some regions appears to be strongly correlated with polynya location and possibly type. Changes in sea level may also have affected the size, location and type of polynya and may explain, in part, why some regions experienced fluctuations in settlement density at various times in the Holocene. Past changes in sea level and climate may serve as predictors of future change in polynya formation with concurrent implications for ecological productivity.

  20. New Paleomagnetic Data for the Franz Josef Land Archipelago and their Tectonic Consequences

    NASA Astrophysics Data System (ADS)

    Abashev, V.; Mikhaltsov, N.

    2014-12-01

    On the base of field work on the Franz Josef Land archipelago (FJL) in 2010 and 2011 the new paleomagnetic data are obtained from the Jurassic-Early Cretaceous magmatic complexes. Main focus of this work was concentrated on the Early-Jurassic basalts widely represented on the Hooker island [1]. Together with the previous data [2] statistically reasonable paleomagnetic pole for the age boundary of 190 million years for the FJL is received (PLat.=62.4; PLon.=140.2; dp/dm=5.5/5.0; N=13). Paleomagnetic data allow to assume that the position of the FJL relative to the Europe in the Early Jurassic significantly differs from the present one. But to the Early Cretaceous it reached relative position very close to the presently observed [2]. We suggest that at least during Early-Middle Jurassic there was rifting processes between the North Barentz terrane (FJL and (may be) Svalbard) and the other part of the European tectonic domain. This rift was accompanied by shifting of the FLJ to the north-eastward on about 500 km. Also obtained paleomagnetic data agree with a hypothesis assuming that the FJL was passing over the Icelandic-Siberian hot spot during Jurassic-Cretaceous time: main paleolatitudes correspond to the Island's present latitude and the paleolatitude of the Siberian trapps. Paleomagnetic study of FJL has a reconnaissance character and cannot lead to any ultimate deductions as the data is obviously not enough. And further work on the basaltic covers of the archipelago seems to be very promising. Research was supported by grant RFBR 13-05-00177. 1. Karyakin Yu.V., Shipilov E.V. Geochemical Specialization and the 40Ar/39Ar Age of Basaltoid Magmatism in the Aleksandra Land, Northbrook, Hooker, and Hayes Island (Franz Josef Land Archipelago) // Doklady Akademii Nauk, 2009, Vol.425, No.2, P. 213-217 (in Russian). 2. Bragin V.Yu., Karyakin Yu.V., Mikhaltsov N.E. The Franz Josef Land archipelago: reconnaissance paleomagnetic data // Large igneous provinces of Asia

  1. Potential for rapid transport of contaminants from the Kara Sea.

    PubMed

    Pfirman, S L; Kögeler, J W; Rigor, I

    1997-08-25

    Export of sea ice from the Kara Sea may redistribute contaminants entrained from atmospheric, marine and riverine sources. Ice exiting the Kara Sea ice to the north, will influence the Fram Strait, Svalbard and Barents Sea regions. Kara Sea ice may also be exported to the Barents Sea through straits north and south of Novaya Zemlya. Some ice from the Kara Sea makes its way into the Laptev Sea to the north and south of Severnaya Zemlya. Data on ice exchange and contaminant levels are not adequate to assess contaminant flux.

  2. Occurrences of whale shark (Rhincodon typus Smith, 1828) in the Saint Peter and Saint Paul archipelago, Brazil.

    PubMed

    Hazin, F H V; Vaske Júnior, T; Oliveira, P G; Macena, B C L; Carvalho, F

    2008-05-01

    The Saint Peter and Saint Paul Archipelago in the central tropical Atlantic, is an important ground of whale sharks that are commonly sighted throughout the year close to the fishing boats in the adjacencies of the islands. In sightings reported between February 2000 and November 2005, the lengths of the individuals ranged between 1.8 to 14.0 m. The causes of these concentrations in the archipelago are still unclear, once there are no upwellings and plankton concentrations for feeding, and no reproductive activities were reported. Nevertheless, they could be associated to the spawning period of the abundant flying fishes, mainly in the first semester, when sightings were more frequent.

  3. Possible refugia in the Alexander Archipelago of southeastern Alaska during the late Wisconsin glaciation

    USGS Publications Warehouse

    Carrara, P.E.; Ager, T.A.; Baichtal, J.F.

    2007-01-01

    The interpretation of the extent of late Wisconsin glaciation in southeastern Alaska has varied between geologists and biologists. Maps and reports of the region prepared by geologists commonly indicated that late Wisconsin ice extended as a large uniform front west to the edge of the continental shelf. However, the distribution of plants and animals in the region has led many biologists to suggest that there may have been ice-free areas that served as refugia during the late Wisconsin. Based on analyses of aerial photographs, topographic maps, and bathymetric charts, in conjunction with a review of previous literature and reconnaissance fieldwork throughout the region, this study presents data supporting a limited ice extent in the Alexander Archipelago during the late Wisconsin and identifies possible ice-free areas that may have served as refugia. These areas include (1) the Fairweather Ground, (2) the Herbert Graves Island area, (3) the western coast of southern Baranof Island and adjacent continental shelf, (4) Coronation Island and the adjacent continental shelf, (5) the Warren Island area, (6) the continental shelf from west of Heceta Island to Forrester Island in the south, (7) parts of the west coast of southern Dall Island, and (8) lowland areas in southern Prince of Wales Island. The identification of these possible refugia has bearing on the recolonization of the Alexander Archipelago, as they could have served as centers of biotic dispersal upon regional deglaciation and as stepping stones for early humans with a maritime tradition entering the western hemisphere from Asia. ?? 2007 NRC Canada.

  4. Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernández Archipelago, Chile.

    PubMed

    López-Sepúlveda, Patricio; Takayama, Koji; Greimler, Josef; Crawford, Daniel J; Peñailillo, Patricio; Baeza, Marcelo; Ruiz, Eduardo; Kohl, Gudrun; Tremetsberger, Karin; Gatica, Alejandro; Letelier, Luis; Novoa, Patricio; Novak, Johannes; Stuessy, Tod F

    2015-01-01

    A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

  5. Phylogeography of Japanese horse chestnut (Aesculus turbinata) in the Japanese Archipelago based on chloroplast DNA haplotypes.

    PubMed

    Sugahara, Kanako; Kaneko, Yuko; Ito, Satoshi; Yamanaka, Keisuke; Sakio, Hitoshi; Hoshizaki, Kazuhiko; Suzuki, Wajiro; Yamanaka, Norikazu; Setoguchi, Hiroaki

    2011-01-01

    Japanese horse chestnut (Aesculus turbinata: Hippocastanaceae) is one of the typical woody plants that grow in temperate riparian forests in the Japanese Archipelago. To analyze the phylogeography of this plant in the Japanese Archipelago, we determined cpDNA haplotypes for 337 samples from 55 populations covering the entire distribution range. Based on 1,313 bp of two spacers, we determined ten haplotypes that are distinguished from adjacent haplotypes by one or two steps. Most of the populations had a single haplotype, suggesting low diversity. Spatial analysis of molecular variance suggested three obvious phylogeographic structures in western Japan, where Japanese horse chestnut is scattered and isolated in mountainous areas. Conversely, no clear phylogeographic structure was observed from the northern to the southern limit of this species, including eastern Japan, where this plant is more common. Rare and private haplotypes were also found in southwestern Japan, where Japanese horse chestnuts are distributed sparsely. These findings imply that western Japan might have maintained a relatively large habitat for A. turbinata during the Quaternary climatic oscillations, while northerly regions could not.

  6. Postglacial formation and dynamics of North Patagonian Rainforest in the Chonos Archipelago, Southern Chile

    NASA Astrophysics Data System (ADS)

    Haberle, S. G.; Bennett, K. D.

    2004-12-01

    Pollen analysis of continuous sediment cores from two lakes in the northern Chonos Archipelago (44°S) in southern Chile shows a complete postglacial record of vegetation change. The fossil records indicate that deglaciation was complete in the northern Chonos by at least 13,600 14C yr BP. Ericaceous heath and grassland persisted for more than 600 years after deglaciation under the influence of dry/cold climates and frequent burning. Nothofagus- Pilgerodendron- Podocarpus forest, with modern analogues in the southern Chonos Archipelago, was established across the northern islands by 12,400 14C yr BP under increasingly warm and wet climates. There is no evidence for a return to cooler climates during the Younger Dryas chronozone. The rise of Tepualia stipularis and Weinmannia trichosperma as important forest components between 10,600 and 6000 14C yr BP may be associated with climates that were warmer than present. The collapse of Pilgerodendron communities during this time may have been triggered by a combination of factors related to disturbance frequency including tephra deposition events, fire and climate change. After 6000 14C yr BP Pilgerodendron recovers and Nothofagus-Pilgerodendron-Tepualia forest persists until the present. European logging and burning activity may have increased the susceptibility of North Patagonian Rainforest to invasion by introduced species and to future collapse of the long-lived Pilgerodendron communities.

  7. Diversity of fruit-feeding butterflies in a mountaintop archipelago of rainforest.

    PubMed

    Pereira, Geanne Carla Novais; Coelho, Marcel Serra; Beirão, Marina do Vale; Braga, Rodrigo Fagundes; Fernandes, Geraldo Wilson

    2017-01-01

    We provide the first description of the effects of local vegetation and landscape structure on the fruit-feeding butterfly community of a natural archipelago of montane rainforest islands in the Serra do Espinhaço, southeastern Brazil. Butterflies were collected with bait traps in eleven forest islands through both dry and rainy seasons for two consecutive years. The influence of local and landscape parameters and seasonality on butterfly species richness, abundance and composition were analyzed. We also examined the partitioning and decomposition of temporal and spatial beta diversity. Five hundred and twelve fruit-feeding butterflies belonging to thirty-four species were recorded. Butterfly species richness and abundance were higher on islands with greater canopy openness in the dry season. On the other hand, islands with greater understory coverage hosted higher species richness in the rainy season. Instead, the butterfly species richness was higher with lower understory coverage in the dry season. Butterfly abundance was not influenced by understory cover. The landscape metrics of area and isolation had no effect on species richness and abundance. The composition of butterfly communities in the forest islands was not randomly structured. The butterfly communities were dependent on local and landscape effects, and the mechanism of turnover was the main source of variation in β diversity. The preservation of this mountain rainforest island complex is vital for the maintenance of fruit-feeding butterfly community; one island does not reflect the diversity found in the whole archipelago.

  8. Copepod distribution and production in a Mid-Atlantic Ridge archipelago.

    PubMed

    Melo, Pedro A M C; De Melo Júnior, Mauro; De Macêdo, Silvio J; Araujo, Moacyr; Neumann-Leitão, Sigrid

    2014-12-01

    The Saint Peter and Saint Paul Archipelago (SPSPA) are located close to the Equator in the Atlantic Ocean. The aim of this study was to assess the spatial variations in the copepod community abundance, and the biomass and production patterns of the three most abundant calanoid species in the SPSPA. Plankton samples were collected with a 300 µm mesh size net along four transects (north, east, south and west of the SPSPA), with four stations plotted in each transect. All transects exhibited a tendency toward a decrease in copepod density with increasing distance from the SPSPA, statistically proved in the North. Density varied from 3.33 to 182.18 ind.m-3, and differences were also found between the first perimeter (first circular distance band) and the others. The total biomass varied from 15.25 to 524.50 10-3 mg C m-3 and production from 1.19 to 22.04 10-3 mg C m-3d-1. The biomass and production of Undinula vulgaris (Dana, 1849), Acrocalanus longicornis Giesbrecht, 1888 and Calocalanus pavo (Dana, 1849) showed differences between some transects. A trend of declining biodiversity and production with increasing distance from archipelago was observed, suggesting that even small features like the SPSPA can affect the copepod community in tropical oligotrophic oceanic areas.

  9. [Marine environment of Nanri Archipelago, Fujian Province in summer: diagnosis and assessment].

    PubMed

    Luo, Dong-Lian

    2011-02-01

    Based on the ecological investigation data in September and October 2007, the status of the marine ecological environment of Nanri Archipelago, Fujian Province in summer was diagnosed and assessed from the aspects of sea water quality, nutrient structure and levels, and biodiversity. The comprehensive quality index method was used for the assessment of the marine ecological environment, and the rationality of the assessment obtained from different indices was also discussed. The sea water pH, dissolved oxygen (DO), chemical oxygen demand (COD), and Pb, Cd, Hg, and As concentrations were all within the limit values of the Grade II standard of Sea Water Quality Standard (GB 3097-1997), while the phosphate concentration at 71% stations, inorganic nitrogen at 14% stations, and oil concentration at 7% stations were all above the Grade II standard of Sea Water Quality Standard. Overall, the seawater quality was of better grade, nutrient structure was characterized by N-limited, most of the sea water was at a state of eutrophication, and the diversity index of plankton was at mildly polluted or unpolluted level. The comprehensive quality index indicated that the seawater quality of the Nanri Archipelago was relatively fine. There existed definite differences in the assessment results by using different diagnosis methods, and hence, a relatively objective assessment about marine environmental quality and health status could only be made when the chemical and biological indicators were comprehensively used.

  10. Ecosystem implications of conserving endemic versus eradicating introduced large herbivores in the Galapagos Archipelago

    USGS Publications Warehouse

    Bastille-Rousseau, Guillaume; Gibbs, James P.; Campbell, Karl; Yackulic, Charles B.; Blake, Stephen

    2017-01-01

    Restoration of damaged ecosystems through invasive species removal and native species conservation is an increasingly common practice in biodiversity conservation. Estimating the degree of ecosystem response attributable specifically to eradication of exotic herbivores versus restoration of native herbivores is often difficult and is complicated by concurrent temporal changes in other factors, especially climate. We investigated the interactive impacts of native mega-herbivores (giant tortoises) and the eradication of large alien herbivores (goats) on vegetation productivity across the Galapagos Archipelago. We examined archipelago-wide patterns of Normalized Difference Vegetation Index (NDVI) as a proxy for vegetation productivity between 2001 and 2015 and evaluated how goat and historical and current tortoise occurrence influenced productivity. We used a breakpoint analysis to detect change in trends in productivity from five targeted areas following goat eradication. We found a positive association between tortoise occurrence and vegetation productivity and a negative association with goat occurrence. We also documented an increase in plant productivity following goat removal with recovery higher in moister regions than in arid region, potentially indicating an alternate stable state has been created in the latter. Climate variation also contributed to the detected improvement in productivity following goat eradication, sometimes obscuring the effect of eradication but more usually magnifying it by up to 300%. Our work offers perspectives regarding the effectiveness and outcomes of eradicating introduced herbivores and re-introducing native herbivores, and the merits of staging them simultaneously in order to restore critical ecosystem processes such as vegetation productivity.

  11. Mesozooplankton distribution in the Spermonde Archipelago (Indonesia, Sulawesi) with special reference to the Calanoida (Copepoda)

    NASA Astrophysics Data System (ADS)

    Cornils, Astrid; Schulz, Jan; Schmitt, Petra; Lanuru, Mahatma; Richter, Claudio; Schnack-Schiel, Sigrid B.

    2010-12-01

    In September 2005 the mesozooplankton distribution, taxonomic composition and community structure were studied on four cross-shelf and one coastal transects in the Spermonde Archipelago off Makassar (SW Sulawesi). A total of 47 higher taxonomic groups and 89 calanoid copepod species were identified. Copepods outnumbered the other mesozooplankton taxa with 29 to 69%, increasing in importance towards the offshore stations. Appendicularians ranked second (16-24%) followed at the offshore stations by chaetognaths (4.5%) and, at shelf and coastal stations by echinoderm pluteus larvae (11-15%). Within the calanoids, species of the family Paracalanidae, especially Paracalanus cf. parvus, were dominant at all stations. Other abundant families were Temoridae (6.5-17%), Acartiidae (7.2%) and Pontellidae (6.2%) at shelf and coastal stations while Clausocalanidae (8.7%) and Calanidae (6.7) were more abundant at offshore stations. To investigate the mesozooplankton distribution the 25 stations were grouped into 3 geographical zones based on their topographical and hydrographical differences (coastal, shelf and offshore zone). Some higher zooplankton taxa and about half of the calanoid species occurred only in one or two categories. In general the abundant taxa were spread throughout the Archipelago. To investigate their distribution the abundance data were subjected to a multivariate discriminant function analysis (MDFA). The results revealed that the composition of the mesozooplankton community changed from the coastal zone with a high abundance of meroplankton and neritic copepod species to an offshore community with a higher abundance of holoplanktonic organisms and oceanic copepod species.

  12. Archipelagos of the Anthropocene: rapid and extensive differentiation of native terrestrial vertebrates in a single metropolis.

    PubMed

    Littleford-Colquhoun, Bethan L; Clemente, Christofer; Whiting, Martin J; Ortiz-Barrientos, Daniel; Frère, Celine H

    2017-05-01

    Some of the best evidence for rapid evolutionary change comes from studies of archipelagos and oceanic islands. City parks are analogous systems as they create geographically isolated green spaces that differ in size, structure and complexity. Very little, however, is known about whether city parks within a single urban centre drive selection and result in the diversification of native species. Here, we provide evidence for the rapid genetic and morphological differentiation of a native lizard (Intellagama lesueurii) at four geographically close yet unconnected parks within one city. Year of establishment of each city park varied from 1855 (oldest) to 2001 (youngest) equating to a generation time range of 32 to three generations. Genetic divergence among city park populations was large despite the small pairwise geographic distances (<5 km) and found to be two to three times higher for microsatellites and three to 33 times higher for mtDNA relative to nonurban populations. Patterns of morphological differentiation were also found to be most extensive among the four city park populations. In contrast to nonurban populations, city park populations showed significant differentiation in relative body size, relative head and limb morphology and relative forelimb and hindlimb length. Crucially, we show that these patterns of differentiation are unlikely to have been caused by founder events and/or drift alone. Our results suggest that city park 'archipelagos' could represent theatres for rapid evolution that may, in time, favour adaptive diversification. © 2017 John Wiley & Sons Ltd.

  13. Coral reef destruction of Small island in 44 years and destructive fishing in Spermonde Archipelago, Indonesia

    NASA Astrophysics Data System (ADS)

    Nurdin, Nurjannah; Komatsu, Teruhisa; Rani, Chair; Supriadi; Fakhriyyah, Sitti; Agus

    2016-11-01

    Coral reefs are among the most diverse and threatened ecosystems on the planet. The most commonly stated for developing coral reef remote sensing techniques is to asses and or to monitor the status of these ecosystems. The study site was selected one of small island in inner zone Spermonde archipelago, Indonesia. We used Landsat MSS, Landsat TM, Landsat ETM, and Landsat OLI data to examine changes in the coral reefs of inner zone island in the Spermonde Archipelago from 1972 to 2016. The image processing are gap fills, atmospheric correction, geometric corrections, image composites, water column corrections, unsupervised classifications, and reclassification. Some of component change detection procedure was applied to define change. The results showed significant changes in 44 years. Disturbed coral reefs are typically characterized by loss of coral cover by increase in the abundance of dead corals and rubble. Local factors such as destructive fishing is direct destruction of inner zone island. While the impact of local threats may be reduced through management action, global threats to coral reefs are likely to increase in severity in the coming years.

  14. Mechanisms of coexistence and competition between ants and land hermit crabs in a Bahamian archipelago

    NASA Astrophysics Data System (ADS)

    Morrison, Lloyd W.

    2006-01-01

    Ants and land crabs are common inhabitants of many coastal and insular communities across the tropics and subtropics, and yet direct evidence of interspecific competition between ants and land crabs has only recently been documented. I conducted a series of observational and manipulative experiments to further elucidate the mechanisms of competition, as well as coexistence, in these two groups in an archipelago of small Bahamian islands. Diel baiting trials demonstrated a significant temporal difference in foraging activity between the land hermit crab, Coenobita clypeatus (Herbst), and ant Brachymyrmex obscurior Forel, suggesting this is one mechanism underlying their coexistence on small oceanic islands. Reciprocal manipulative baiting experiments, in which one of a pair of species was removed from baits, documented that aggressive interspecific interactions underlie patterns of complementary distribution and temporal turnover at rich food resources. This was true for competition between hermit crabs and B. obscurior, and between B. obscurior and a second ant species, Dorymyrmex pyramicus Roger. Negative species associations at baits were found to be common throughout an archipelago of 69 small islands. A trade-off in exploitative and interference abilities may be a second mechanism allowing species coexistence on these small islands. Interspecific interactions such as competition and predation may occur commonly between ants and land crabs and have important consequences for the structure and function of tropical and subtropical insular ecosystems.

  15. Whistle characteristics of the spinner dolphin population in the Comoros Archipelago.

    PubMed

    Bonato, M; Papale, E; Pingitore, G; Ricca, S; Attoumane, A; Ouledi, A; Giacoma, C

    2015-11-01

    Observed variations in dolphin acoustic signals may be associated with behavior, social composition, and local differences in habitat features. This study aims at characterizing whistles emitted by the spinner dolphin population occurring in the waters of the main island of the Archipelago of Comoros (Mozambique Channel, Indian Ocean) and to assess factors possibly influencing the acoustic structure of signals. All parameters examined on 953 whistles significantly differed in relation to environmental conditions, group size, and behavior. By mixed model analysis, it was found that only habitat characteristics play a role in the variation of frequency parameters, and exerted on the acoustic structure of whistles stronger influence than socio-behavioral factors. Spinner dolphins occurring in the Comoros archipelago use higher frequencies and show longer signal duration compared to those from the Pacific and the Atlantic. Results suggest that frequency parameters are distinctive of the local population and reflect the habitat use of the species in the area. In conclusion, acoustic measurements may be crucial elements to be included in monitoring programs to identify local peculiarities of dolphins' populations.

  16. MERCURY CONCENTRATIONS OF A RESIDENT FRESHWATER FORAGE FISH AT ADAK ISLAND, ALEUTIAN ARCHIPELAGO, ALASKA

    PubMed Central

    Kenney, Leah A.; von Hippel, Frank A.; Willacker, James J.; O’Hara, Todd M.

    2015-01-01

    The Aleutian Archipelago is an isolated arc of over 300 volcanic islands stretching 1,600 km across the interface of the Bering Sea and North Pacific Ocean. Although remote, some Aleutian Islands were heavily impacted by military activities from World War II until recently and were exposed to anthropogenic contaminants, including mercury (Hg). Mercury is also delivered to these islands via global atmospheric transport, prevailing ocean currents, and biotransport by migratory species. Mercury contamination of freshwater ecosystems is poorly understood in this region. Total Hg (THg) concentrations were measured in threespine stickleback fish (Gasterosteus aculeatus) collected from eight lakes at Adak Island, an island in the center of the archipelago with a long military history. Mean THg concentrations for fish whole-body homogenates for all lakes ranged from 0.314 to 0.560 mg/kg dry weight. Stickleback collected from seabird-associated lakes had significantly higher concentrations of THg compared to non-seabird lakes, including all military lakes. The δ13C stable isotope ratios of stickleback collected from seabird lakes suggest an input of marine-derived nutrients and/or marine-derived Hg. PMID:22912068

  17. The Melithaeidae (Cnidaria: Octocorallia) of the Ryukyu Archipelago: molecular and morphological examinations.

    PubMed

    Aguilar-Hurtado, Catalina; Nonaka, Masanori; Reimer, James D

    2012-07-01

    The family Melithaeidae (Octocorallia: Alcyonacea) is distributed in the West Pacific, Indian Ocean and the Red Sea. They are most abundant in warmer waters but can also be found in temperate waters. At present six genera are assigned to this family (Melithaea, Mopsella, Clathraria, Acabaria, Wrightella and Asperaxis), however overlapping characteristics make this group's taxonomic identification difficult and their relationships unclear. There are only a few reports from the Ryukyu Archipelago in southern Japan of melithaeids and most other octocorals, despite the islands being an area of high octocoral diversity. To help resolve the taxonomic confusion in this family, samples from various Ryukyu Archipelago locations were collected and DNA sequences of nuclear 28S ribosomal DNA and mitochondrial cytochrome oxidase I (COI) were obtained. Additionally, SEM micrographs of the sclerites of specimens were taken to further confirm the molecular results. Three strongly supported clades were recovered from the COI and 28S rDNA analyses, corresponding to Melithaea, Acabaria, and Mopsella, and in most cases clades were clearly related with the sclerite shape reported for each genus. These results show clearly that molecular differences are present between the three genera, and also demonstrates the strong need of other molecular markers for resolving intra-generic phylogenies. Our results provide baseline data for future studies of this octocoral family, not only on taxonomy, but also with regards to their distribution in the Ryukyu Islands.

  18. [Helminth fauna of the bank vole myodes glareolus (Schreber, 1780) in the Kizhi Archipelago].

    PubMed

    Bugmyrin, S V; Korosov, A V; Bespyatova, L A; Ieshko, E P

    2015-01-01

    The present study was aimed to examine the specific features of the helminth fauna in insular populations of the bank vole (Myodes glareolus) in the north of the species range. The material was collected in and nearby the Kizhi Archipelago (Lake Onega, 62°1' N 35°12' E) during August 1997, 2005-2007, 2012 and 2013. Small mammals were trapped on 23 islands (varying from 2 to 15,000 ha) and on the mainland. Helminthological met- hods were applied to examine 301 specimens of M glareolus. Fourteen helminth species were found: trematodes--Skrjabinoplagiorchis vigisi; cestodes--Paranoplocephala omphalodes, P. gracilis, Catenotaenia henttoneni, Taenia mustelae, Cladotaenia globife- ra, Spirometra erinacei; nematodes--Trichocephalus muris, Aonchotheca murissylvatici, Hepaticola hepatica, Heligmosomum mixtum, Heligmosomoides glareoli, Longistriata minuta, Syphacia petrusewiczi. The parasites S. vigisi, S. erinaci, H. hepatica and T. muris were identified in the bank vole in Karelia for the first time. Significant differences were detected between the helminth faunas of local insular populations of the bank vole. A distinctive feature of all small islands was that samples from them lacked the widespread pa- rasitic nematode Heligmosomum mixtum. The studies have confirmed the general trends observed in the parasite fauna of most isolated populations of small mammals: a poorer species diversity and high infestation rates with certain species of parasites. The Kizhi Archipelago is characterized by the specific high abundance of regionally rare parasite species (H hepatica, A. murissylvatici), and by the absence of common parasites (H. mixtum, H. glareoli).

  19. Copepod distribution and production in a Mid-Atlantic Ridge archipelago.

    PubMed

    Melo, Pedro A M C; Melo Júnior, Mauro DE; Macêdo, Silvio J DE; Araujo, Moacyr; Neumann-Leitão, Sigrid

    2014-11-11

    The Saint Peter and Saint Paul Archipelago (SPSPA) are located close to the Equator in the Atlantic Ocean. The aim of this study was to assess the spatial variations in the copepod community abundance, and the biomass and production patterns of the three most abundant calanoid species in the SPSPA. Plankton samples were collected with a 300 µm mesh size net along four transects (north, east, south and west of the SPSPA), with four stations plotted in each transect. All transects exhibited a tendency toward a decrease in copepod density with increasing distance from the SPSPA, statistically proved in the North. Density varied from 3.33 to 182.18 ind.m-3, and differences were also found between the first perimeter (first circular distance band) and the others. The total biomass varied from 15.25 to 524.50 10-3 mg C m-3 and production from 1.19 to 22.04 10-3 mg C m-3d-1. The biomass and production of Undinula vulgaris (Dana, 1849), Acrocalanus longicornis Giesbrecht, 1888 and Calocalanus pavo (Dana, 1849) showed differences between some transects. A trend of declining biodiversity and production with increasing distance from archipelago was observed, suggesting that even small features like the SPSPA can affect the copepod community in tropical oligotrophic oceanic areas.

  20. Exchanges of volume, heat and freshwater through the Canadian Arctic Archipelago: a numerical study.

    NASA Astrophysics Data System (ADS)

    Grivault, Nathan; Hu, Xianmin; Myers, Paul G.

    2016-04-01

    The Canadian Arctic Archipelago (CAA) is a tangle of shallow basins interlinked by narrow straits. It is the main pathway of liquid freshwater from the Arctic Ocean to North Atlantic. It also receives runoff from the Mackenzie River and the glaciers of the different islands that composes the archipelago. This study is based on a set of numerical experiments using a regional configuration of the coupled ocean/sea-ice general circulation model NEMO. We consider a long-term hindcast (1958-2014) as well as the more recent period (2002-2014) using high resolution inter-annual forcing from Environment Canada. We used an improved mapping of runoff to ensure correct amounts of freshwater are added to the system. We evaluate the flow pathways through the CAA, as well as the transport of volume, heat and freshwater. Results are evaluated against observational sections. We also look at the variability and the dynamics driving it. Passive tracers are used to complement the analysis.

  1. Modelling population persistence on islands: mammal introductions in the New Zealand archipelago.

    PubMed

    Duncan, Richard P; Forsyth, David M

    2006-12-07

    Islands are likely to differ in their susceptibility to colonization or invasion due to variation in factors that affect population persistence, including island area, climatic severity and habitat modification. We tested the importance of these factors in explaining the persistence of 164 introductions of six mammal species to 85 islands in the New Zealand archipelago using survival analysis and model selection techniques. As predicted by the theory of stochastic population growth, extinction risk was the greatest in the period immediately following introduction, declining rapidly to low probability by ca 25 years. This suggests that initially small populations were at greatest risk of extinction and that populations which survived for 25 years were likely to persist subsequently for much longer. Islands in the New Zealand archipelago become colder and windier with increasing latitude, and the probability of mammal populations persisting on islands declined steeply with increasing latitude. Hence, our results suggest that climatic suitability was an important determinant of the outcome of these invasions. The form of the relationship between latitude and persistence probability differed among species, emphasizing that the outcome of colonization attempts is species-environment specific.

  2. Diversity of fruit-feeding butterflies in a mountaintop archipelago of rainforest

    PubMed Central

    Pereira, Geanne Carla Novais; Beirão, Marina do Vale; Braga, Rodrigo Fagundes; Fernandes, Geraldo Wilson

    2017-01-01

    We provide the first description of the effects of local vegetation and landscape structure on the fruit-feeding butterfly community of a natural archipelago of montane rainforest islands in the Serra do Espinhaço, southeastern Brazil. Butterflies were collected with bait traps in eleven forest islands through both dry and rainy seasons for two consecutive years. The influence of local and landscape parameters and seasonality on butterfly species richness, abundance and composition were analyzed. We also examined the partitioning and decomposition of temporal and spatial beta diversity. Five hundred and twelve fruit-feeding butterflies belonging to thirty-four species were recorded. Butterfly species richness and abundance were higher on islands with greater canopy openness in the dry season. On the other hand, islands with greater understory coverage hosted higher species richness in the rainy season. Instead, the butterfly species richness was higher with lower understory coverage in the dry season. Butterfly abundance was not influenced by understory cover. The landscape metrics of area and isolation had no effect on species richness and abundance. The composition of butterfly communities in the forest islands was not randomly structured. The butterfly communities were dependent on local and landscape effects, and the mechanism of turnover was the main source of variation in β diversity. The preservation of this mountain rainforest island complex is vital for the maintenance of fruit-feeding butterfly community; one island does not reflect the diversity found in the whole archipelago. PMID:28666003

  3. Mercury concentrations of a resident freshwater forage fish at Adak Island, Aleutian Archipelago, Alaska.

    PubMed

    Kenney, Leah A; von Hippel, Frank A; Willacker, James J; O'Hara, Todd M

    2012-11-01

    The Aleutian Archipelago is an isolated arc of over 300 volcanic islands stretching 1,600 km across the interface of the Bering Sea and North Pacific Ocean. Although remote, some Aleutian Islands were heavily impacted by military activities from World War II until recently and were exposed to anthropogenic contaminants, including mercury (Hg). Mercury is also delivered to these islands via global atmospheric transport, prevailing ocean currents, and biotransport by migratory species. Mercury contamination of freshwater ecosystems is poorly understood in this region. Total Hg (THg) concentrations were measured in threespine stickleback fish (Gasterosteus aculeatus) collected from eight lakes at Adak Island, an island in the center of the archipelago with a long military history. Mean THg concentrations for fish whole-body homogenates for all lakes ranged from 0.314 to 0.560 mg/kg dry weight. Stickleback collected from seabird-associated lakes had significantly higher concentrations of THg compared to non-seabird lakes, including all military lakes. The δ(13)C stable isotope ratios of stickleback collected from seabird lakes suggest an input of marine-derived nutrients and/or marine-derived Hg.

  4. A multiproxy reconstruction of NAO evolution in the Azores archipelago since 1350 AD

    NASA Astrophysics Data System (ADS)

    Hernández, Armand; Doolittle, Sara; Bao, Roberto; Trigo, Ricardo M.; Rubio-Inglés, Maria J.; Sánchez-López, Guiomar; Vázquez-Loureiro, David; Gonçalves, Vitor; Raposeiro, Pedro M.; Marques, Helena S.; Sáez, Alberto; Giralt, Santiago

    2014-05-01

    The North Atlantic Oscillation (NAO) is the main atmospheric circulation pattern affecting climate variability in the Northern Hemisphere, having a major impact on both marine and terrestrial ecosystems. Instrumental records of the NAO are relatively short, and therefore paleoenvironmental multiproxy approaches become fundamental to better understand its behaviour for longer scale periods. The NAO is often defined as a large-scale meridional oscillation dipole of air pressure between the Azores High and the Iceland Low. Some of the NAO definitions include the use of sea level pressure from Ponta Delgada station in Azores, and thus any NAO reconstruction would gain in robustness if it includes paleoenvironmental information from this archipelago located at the southern end of the meridional dipole that characterizes the NAO pattern. However, to the best of our knowledge, very few historical and long-term reconstructions have been conducted in the Azores Islands. We present a ca. 600-year-long multiproxy reconstruction of the NAO evolution based on facies analysis, X-ray diffraction (XRD), X-ray fluorescence (XRF) core scanning, elemental and isotope geochemistry on bulk organic matter and the preliminary study of diatom and chironomid content from the sedimentary record of Lake Empadadas (37° 49' N - 25° 44' W, Azores Archipelago, Portugal). The precipitation regime in Azores Archipelago (i.e. intra and inter-annual variability) is clearly influenced by the NAO index, thus periods with dominant positive NAO index values (NAO+) are usually characterized by low winter precipitation in the Azores. Conversely, negative NAO phases (NAO-) induce high winter precipitation in the archipelago. These patterns suggest that past (winter) precipitation changes on the Azores may be partially used as a proxy for NAO changes, and thus a proxy for more large-scale changes in the North Atlantic region. According to this multiproxy characterization of the Lake Empadadas sediments

  5. Glacier Changes in the Russian High Arctic.

    NASA Astrophysics Data System (ADS)

    Pritchard, M. E.; Willis, M. J.; Melkonian, A. K.; Golos, E. M.; Stewart, A.; Ornelas, G.; Ramage, J. M.

    2014-12-01

    We provide new surveys of ice speeds and surface elevation changes for ~40,000 km2 of glaciers and ice caps at the Novaya Zemlya (NovZ) and Severnaya Zemlya (SevZ) Archipelagoes in the Russian High Arctic. The contribution to sea level rise from this ice is expected to increase as the region continues to warm at above average rates. We derive ice speeds using pixel-tracking on radar and optical imagery, with additional information from InSAR. Ice speeds have generally increased at outlet glaciers compared to those measured using interferometry from the mid-1990s'. The most pronounced acceleration is at Inostrantseva Glacier, one of the northernmost glaciers draining into the Barents Sea on NovZ. Thinning rates over the last few decades are derived by regressing stacked elevations from multiple Digital Elevations Models (DEMs) sourced from ASTER and Worldview stereo-imagery and cartographically derived DEMs. DEMs are calibrated and co-registered using ICESat returns over bedrock. On NovZ thinning of between 60 and 100 meters since the 1950s' is common. Similar rates between the late 1980s' and the present are seen at SevZ. We examine in detail the response of the outlet glaciers of the Karpinsky and Russanov Ice Caps on SevZ to the rapid collapse of the Matusevich Ice Shelf in the late summer of 2012. We do not see a dynamic thinning response at the largest feeder glaciers. This may be due to the slow response of the cold polar glaciers to changing boundary conditions, or the glaciers may be grounded well above sea level. Speed increases in the interior are difficult to assess with optical imagery as there are few trackable features. We therefore use pixel tracking on Terra SARX acquisitions before and after the collapse of the ice shelf to compute rates of flow inland, at slow moving ice. Interior ice flow has not accelerated in response to the collapse of the ice shelf but interior rates at the Karpinsky Ice Cap have increased by about 50% on the largest outlet

  6. The potential role of hurricanes in the creation and maintenance of Kirtland's warbler winter habitat in the Bahamian Archipelago.

    Treesearch

    Joseph Wunderle; David Currie; David N. Ewert

    2007-01-01

    The threatened migratory Kirtland’s Warbler (KW, Dendorica kirtlandii) breeds exclusively in Michigan and overwinters nearly exclusively in the Bahamas Archipelago, where little is known of its winter habitat. Previous observations and our own studies indicate that KWs routinely use early successional or regenerating shrubby habitats on Eleuthera. Our preliminary...

  7. The tectonic evolution of the Madrean Archipelago and its impact on the geoecology of the Sky Islands

    Treesearch

    David Coblentz

    2005-01-01

    While the unique geographic location of the Sky Islands is well recognized as a primary factor for the elevated biodiversity of the region, its unique tectonic history is often overlooked. The mixing of tectonic environments is an important supplement to the mixing of flora and faunal regimes in contributing to the biodiversity of the Madrean Archipelago. The Sky...

  8. Conference summary: Biodiversity and management of the Madrean Archipelago III: Closing remarks and notes from the concluding session

    Treesearch

    Dale S. Turner; Alejandro Castellanos

    2013-01-01

    During the first week of May 2012, the Third Conference on Biodiversity and Management of the Madrean Archipelago brought together more than 300 people with an interest in this region. It included scientists, land managers, activists, and land owners from both sides of the international border. After three and a half days of presentations, the participants gathered for...

  9. Changes in driftwood delivery to the Canadian Arctic Archipelago: The hypothesis of postglacial oscillations of the transpolar drift

    USGS Publications Warehouse

    Dyke, A.S.; England, J.; Reimnitz, E.; Jette, H.

    1997-01-01

    Driftwood appears to be absent in the Beaufort Gyre but abundant in parts of the Transpolar Drift (TPD), which crosses the Arctic Ocean from the Chukchi Sea to the vicinity of northeastern Greenland. Nearly 300 radiocarbon dates on Holocene driftwood from the Canadian Arctic Archipelago reveal two regions with contrasting histories of driftwood incursion: the region accessible to wood brought into Baffin Bay by the West Greenland Current and the rest of the archipelago, which receives wood from the Arctic Ocean. We hypothesize that when the TPD was deflected westward along northern Greenland, wood was delivered widely to the Canadian Arctic Archipelago; when the TPD exited entirely through Fram Strait via the East Greenland Current, little or no wood was delivered to most of the archipelago, but some continued into Baffin Bay via the West Greenland Current. A split TPD delivered wood to both regions. The regional driftwood incursion histories exhibit multiple maxima and minima that can be explained by this hypothesis. The Larix to Picea ratio of wood arriving in the Canadian Arctic Archipelago has also changed through time. This may indicate varying contributions from Russian versus North American sources, which in turn may indicate variable mixing of wood en route. The inferred discharge paths of the TPD were apparently stable for intervals ranging from several millennia to centuries or perhaps only decades. The last major switch broadly correlates with the onset of Neoglaciation. Variations in the path and strength of the TPD may have important oceanographic and climatic consequences downstream in the North Atlantic Ocean.

  10. The Physical Basis for the Lg/P Discriminant: Signal Characteristics and Modeling

    DTIC Science & Technology

    1997-11-01

    limited to a few source areas (viz. the Nevada Test Site (NTS) in the United States, the former Soviet test sites in eastern Kazakhstan and at Novaya...Zemlya, and the Chinese test site at Lop Nor). In addition, the data included several PNE explosions in the former Soviet Union recorded at a single...the former Soviet test sites , and at intermediate and far-regional distances from the Lop Nor explosions. For comparison, earthquakes and other source

  11. Development and Tuning of a 3-D Stochastic Inversion Methodology for the European Arctic

    DTIC Science & Technology

    2008-09-01

    west of the (most likely) Late Triassic-Early Jurassic Novaya Zemlya Fold Belt. The nature of the underlying crystalline crust and upper mantle in...10 and 150 s period were combined with existing data provided by the University of Colorado at Boulder. This new data set was inverted for maps...showing the 2D group-velocity distribution of Love and Rayleigh waves for specific periods . Using a Monte Carlo inversion technique (Shapiro and

  12. Three-Dimensional Finite Difference Modeling of Surface Wave Propagation Across the Barents Shelf

    DTIC Science & Technology

    1991-10-01

    crust in the vicinity of Spitsbergen and Franz Josef Land. For propagation paths to Europe, Greenland, and North America the surface waves must... Franz Josef Land, to the southwest by the Kola and Kanin Peninsulas, and to the south by the Pechora Basin. Novaya Zemlya is considered an extension...reduced sedimentary cover. Similarly, the Svalbard platform and regions around Spitsbergen and Franz Josef Land to the north are continental crust (40 kin

  13. Navy Tactical Applications Guide. Volume 8. Weather Analysis and Forecast Applications. Part 1. Arctic: Greenland/Norwegian/Barents Seas. Meteorological Satellite Systems

    DTIC Science & Technology

    1989-09-01

    Novaya Zemlya. Faint cloud plumes are evident extending westward from the polynya southwest of the Franz Josef Land island group. Using these and other...and should have been positioned further north. By using the polynya cloud plume indications in Fig. ID-3a, which indicate northeasterly flow in...Svalbard and Franz Josef Land. The presence of a cloud plume from the polynya south of Kvitoya verifies open water in that region. A final view of the

  14. Military Modernization and the Russian Ground Forces

    DTIC Science & Technology

    2011-06-01

    role in shaping Russian society. The military, indeed, saw itself as a force for social good. There was a sense that all young Russian men should...experience conscript service as a means of creating a sense of na- tional pride. Previously, in Soviet times, the military had been the only state...institution that could develop in young men, from Lithuania to Kyrgyzstan, and from Novaya Zemlya to Sakhalin, a sense of ”sovietness,” of nationhood

  15. Near Source Contributions to Teleseismic P Wave Coda and Regional Phases

    DTIC Science & Technology

    1991-04-27

    coda - 15. NUMBER OF-PAGES Underground explosions Teleseismic, waves -_140 P waves Splain16. -PRICE CODE pP parameters Salto 17. SECURITY CLSSIFICATION...short-period vertical component recordings for underground explosions at the Nevada (NTS) and Novaya Zemlya test sites. The waveforms were recorded at...receiver terms for the two CSN stations from Figure 2 for the 25 Pahute Mesa explosions. The P and P Co6da station’ spectra are showw withl- vertical

  16. Prognathodes basabei, a new species of butterflyfish (Perciformes, Chaetodontidae) from the Hawaiian Archipelago

    PubMed Central

    Pyle, Richard L.; Kosaki, Randall K.

    2016-01-01

    Abstract A new species of the butterflyfish genus Prognathodes is described from specimens collected at a depth of 55–61 m off Pearl and Hermes Atoll, Northwestern Hawaiian Islands. This species has been observed by mixed-gas divers and from submersibles at depths ranging from 45–187 m throughout the Hawaiian Archipelago, with shallower sightings in the Northwestern Hawaiian Islands and deeper in the Main Hawaiian Islands. It is similar to Prognathodes guezei (Maugé and Bauchot 1976) from the western Indian Ocean, and at least one other undescribed species of Prognathodes from Palau, differing from these species in the number of soft dorsal-fin rays, size of head, and body depth. There are also differences in the life color, and a substantial genetic difference from the Palauan species (d » .08 in mtDNA cytochrome oxidase I). PMID:27667937

  17. Apolar compounds in seaweeds from fernando de noronha archipelago (northeastern coast of Brazil).

    PubMed

    Ferreira, Leandro De Santis; Turatti, Izabel Cristina Casanova; Lopes, Norberto Peporine; Guaratini, Thais; Colepicolo, Pio; Oliveira Filho, Eurico Cabral; Garla, Ricardo Clapis

    2012-01-01

    Hyphenated techniques of gas chromatography coupled to mass spectrometer were used to determine fatty acids in eleven species of seaweeds from Fernando de Noronha archipelago. The main compounds detected in all studied species were the alcohol phytol and the fatty acids 14 : 0; 15 : 0; 16 : 0; 18 : 0; 18 : 1 n(9); 18 : 2 Δ(9,12); 20 : 4; 20 : 5. These fatty acids are commonly found in seaweeds present in warm regions. Thus, we found no specificity in the presence of a particular set of fatty acids and the studied species indicating that they are not useful as taxonomic indicators. However, they could be used in a comparative study with algae found in polluted area because many of the studied seaweeds are widespread and Fernando de Noronha has low human influence.

  18. Apolar Compounds in Seaweeds from Fernando de Noronha Archipelago (Northeastern Coast of Brazil)

    PubMed Central

    Ferreira, Leandro De Santis; Turatti, Izabel Cristina Casanova; Lopes, Norberto Peporine; Guaratini, Thais; Colepicolo, Pio; Oliveira Filho, Eurico Cabral; Garla, Ricardo Clapis

    2012-01-01

    Hyphenated techniques of gas chromatography coupled to mass spectrometer were used to determine fatty acids in eleven species of seaweeds from Fernando de Noronha archipelago. The main compounds detected in all studied species were the alcohol phytol and the fatty acids 14 : 0; 15 : 0; 16 : 0; 18 : 0; 18 : 1 n9; 18 : 2 Δ9,12; 20 : 4; 20 : 5. These fatty acids are commonly found in seaweeds present in warm regions. Thus, we found no specificity in the presence of a particular set of fatty acids and the studied species indicating that they are not useful as taxonomic indicators. However, they could be used in a comparative study with algae found in polluted area because many of the studied seaweeds are widespread and Fernando de Noronha has low human influence. PMID:22272200

  19. Tectonic stability since the last interglacial offsets the Glorieuses Islands from the nearby Comoros archipelago

    NASA Astrophysics Data System (ADS)

    Guillaume, M. M. M.; Reyss, J.-L.; Pirazzoli, P. A.; Bruggemann, J. H.

    2013-09-01

    The four fossil terraces of the Glorieuses Islands are described, and new dates are provided to resolve their stratigraphy, depositional setting, and tectonic behavior. Most outcrops consist of a single sedimentary unit that represents the remains of an extensive reef flat dominated by Isopora palifera corals. At Lys Island, this unit is locally overlain by dipping layered beds composed of Halimeda segments, tentatively interpreted as storm overwash. Reliable U/Th dates obtained from corals sampled from the fossil outcrops mostly fall between 127 and 123 kyr, suggesting that these reefs formed exclusively during the first MIS-5e sea-level highstand, when sea level reached +3 m. The mean elevation of these terraces being +4.5 m, an uplift of 0.012 ± 0.002 mm year-1 is inferred. This relative tectonic stability contrasts with the subsidence reported from Mayotte Island, suggesting a different geologic setting for the nearby Comoros and Glorieuses archipelagoes.

  20. Biology of Anopheles saperoi, an Endemic Species in Okinawajima, the Ryukyu Archipelago, Japan.

    PubMed

    Mannen, Kosuke; Toma, Takako; Minakawa, Noboru; Higa, Yukiko; Miyagi, Ichiro

    2016-03-01

    Biological studies of Anopheles saperoi were conducted using larval and adult mosquito collections in the northern part of Okinawajima of the Ryukyu Archipelago from June 2009 to July 2010. Anopheles saperoi was the most collected species in the northern Okinawajima, except Motobu Peninsula, where it was not collected. The southern distribution of An. saperoi was Sugita Stream, Nago City. Anopheles saperoi was collected throughout the year with reproduction (gonotrophic cycle) observed year-round. Immature densities varied for Hinna and Yona streams, and were negatively affected by precipitation patterns. Human attraction activity of females varied for by study area and collection time and was positively affected by temperature, but negatively by heavy rainfall. The greatest female human attraction activity was observed during 3:00-5:00 p.m., with peak at twilight. Parity rates varied from 23.1% to 83.3% throughout the year.

  1. A new species of Gnathia (Isopoda: Cymothoida: Gnathiidae) from Okinawajima Island, Ryukyu Archipelago, southwestern Japan.

    PubMed

    Ota, Yuzo; Tanaka, Katsuhiko; Hirose, Euichi

    2007-12-01

    Gnathia limicola sp. nov. is described from Okinawajima Island, Ryukyu Archipelago, southwestern Japan. Burrows of this species were found in a small intertidal creek bank on a muddy tidal flat near mangrove trees. Adult males differ from those of other Gnathia species in the following features: (1) fine setae cover peduncle articles 1 and 2 of antenna 1, peduncle articles 1-3 of antenna 2, and the erisma of the mandibles; (2) the ventral frontal border of the cephalon is medianly notched, and the lateral parts extend beyond the dorsal frontal border; and (3) the penes are fused into a thin rectangular blade directed posteriorly. Adult females and praniza larvae were also distinguished morphologically from other Gnathia species. Based on field and laboratory observations, the mating behavior of this species appears similar to that of Paragnathia formica (Hesse, 1862), which inhabits salt marshes in Europe and North Africa.

  2. Description of female pupa and larva of Ficalbia ichiromiyagii from Iriomote Island, Ryukyu Archipelago, Japan.

    PubMed

    Higa, Yukiko; Toma, Takako; Miyagi, Ichiro

    2012-12-01

    We describe and illustrate for the 1st time the pupa and larva of adult female Ficalbia ichiromiyagii based on specimens collected from a swamp forest in Otomi, Iriomote Island, Ryukyu Archipelago, Japan. The pupa has a trumpet that is 6.25 times its breadth at halfway, with a long meatal cleft line; setae 6-I, II considerably long, usually single or bifid; median caudal seta absent; and paddle edge serrated only on the outer apical half. The larva is characterized by dark pigmentation of the head and siphon, seta I-C elongate and spiniform, usually with a short lateral spine on the inner basal side and siphon with 1 pecten spine and conspicuous seta 1-S at the base. The immature stages were found only in undisturbed jungle swamps with dense vegetation.

  3. Population dynamics of intertidal oribatid mites (Acari: Cryptostigmata) from the subtropical archipelago of Bermuda.

    PubMed

    Pfingstl, Tobias

    2013-10-01

    The population dynamics of the three intertidal oribatid species, Alismobates inexpectatus, Fortuynia atlantica and Carinozetes bermudensis, have been studied on the archipelago of Bermuda over the course of a year. All three species are univoltine, showing a clear seasonal demographic pattern, with reproduction from spring to late autumn and a complete standstill of egg production in winter. A seasonal shift in sex ratio could also be observed in all three species and is supposed to be based on sex-dependent mortality. The subtropical climate of Bermuda allows longer reproductive periods than shown in other intertidal or edaphic temperate species and temperature is supposed to be the main factor influencing the demography of these intertidal dwelling mites. Although all three Bermudian species exhibit the same basic seasonal demographic pattern, there are slight temporal shifts in population dynamics, presumably caused by local microclimatic differences among the populations. Larviparity, shown in other littoral oribatid mites, is clearly absent in the present species.

  4. Pearl oysters Pinctada margaritifera grazing on natural plankton in Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia).

    PubMed

    Fournier, Jonathan; Dupuy, Christine; Bouvy, Marc; Couraudon-Réale, Marine; Charpy, Loïc; Pouvreau, Stephane; Le Moullac, Gilles; Le Pennec, Marcel; Cochard, Jean-Claude

    2012-01-01

    In atoll lagoons of French Polynesia, growth and reproduction of pearl oysters are mainly driven by plankton concentration. However, the actual diet of black-lip pearl oysters Pinctada margaritifera in these lagoons is poorly known. To fill this gap, we used the flow through chamber method to measure clearance rates of P. margaritifera in Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia). We found: (i) that pearl oysters cleared plankton at a rate that was positively related to plankton biovolume, (ii) that nanoflagellates were the main source of carbon for the pearl oysters, and (iii) that the quantity and origin of carbon filtrated by pearl oysters was highly dependent on the concentration and composition of plankton. These results provide essential elements for the comprehension of growth and reproduction variability of pearl oysters in atoll lagoons of French Polynesia.

  5. Pre- and post-1998 ENSO records of shallow-water octocorals (Alcyonacea) in the Chagos Archipelago.

    PubMed

    Schleyer, Michael H; Benayahu, Yehuda

    2010-12-01

    When compared, principal octocorals collected in the Chagos Archipelago before and after the 1998 ENSO shared many common taxa. While a few discontinuities in their biodiversity revealed subtle changes in more persistent genera (Lobophytum, Sarcophyton), some fast-growing "fugitive" genera (e.g. Cespitularia, Efflatounaria, Heteroxenia) disappeared after the ENSO-related coral bleaching. Such transient fugitives might thus be eliminated from soft coral communities on isolated reef systems, possibly in the long term, by events of this nature. The appearance of Carijoa riseii, a species often considered a fouling organism, even an invasive, may well be indicative of reef degradation during the ENSO event. The post-ENSO recovery manifested by this fauna nevertheless gives cause for hope for their survival in the face of climate change. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Sea ice conditions and melt season duration variability within the Canadian Arctic Archipelago: 1979-2008

    NASA Astrophysics Data System (ADS)

    Howell, Stephen E. L.; Duguay, Claude R.; Markus, Thorsten

    2009-05-01

    Sea ice conditions and melt season duration within the Canadian Arctic Archipelago (CAA) were investigated from 1979-2008. The CAA is exhibiting statistically significant decreases in average September total sea ice area at -8.7% decade-1. The melt season duration within the CAA is increasing significantly at 7 days decade-1. 2008 represented the longest melt season duration within the CAA over the satellite record at 129 days. Average September multi-year ice (MYI) area is decreasing at -6.4% decade-1 but has yet to reach statistical significance as a result of increasing MYI dynamic import from the Arctic Ocean. Results also find that the Western Parry Channel (WPC) region of the Northwest Passage (NWP) will continue to be susceptible to MYI as the transition to a summer-time sea ice free Arctic continues. The processes responsible for the temporary clearing of the WPC region of the NWP in 2007 were also identified.

  7. Ticks on passerines from the Archipelago of the Azores as hosts of borreliae and rickettsiae.

    PubMed

    Literak, Ivan; Norte, Ana Claudia; Núncio, Maria Sofia; de Carvalho, Isabel Lopes; Ogrzewalska, Maria; Nováková, Markéta; Martins, Thiago F; Sychra, Oldrich; Resendes, Roberto; Rodrígues, Pedro

    2015-07-01

    We examined the presence of borreliae and rickettsiae bacteria in ticks from wild passerine birds on three islands of the Archipelago of the Azores, the westernmost region of Palearctic. A total of 266 birds belonging to eight species from seven families were examined on São Miguel, Santa Maria and Graciosa islands in 2013. Ticks collected from these birds consisted of 55 Ixodes frontalis (22 larvae, 32 nymphs, 1 adult female) and 16 Haemaphysalis punctata nymphs. Turdus merula and Erithacus rubecula were the birds most infested with both tick species. Three T. merula in Santa Maria were infested with 4 I. frontalis infected with Borrelia turdi. No rickettsiae were found in the ticks. We report for the first time the presence of I. frontalis and B. turdi on the Azores islands and we showed that the spatial distribution reaches further west than previously thought.

  8. [Malaria in the islands of the Comoro archipelago. Historical and geophysical aspects. Epidemiologic considerations].

    PubMed

    Julvez, J; Blanchy, S

    1988-01-01

    Located on the maritime road to India, important harbour during slavery period, Comoro Archipelago was therefore free of malaria in the XVIIth century in spite of the presence of infected persons. In the XIXth century, malaria became endemic in Mayotte, Mohéli and Anjouan but only at the beginning of the XXth century in Grande Comore. The origin of vectors and main parasite, P. falciparum, are african. After quite a "natural" evolution, the situation is the same in these islands (continual high transmission) except Mayotte where a malaria programme is performed since 1976. But the historical differences, island by island, in the outbreak of malaria suggest various ecological balance which would be underlined by antimalarial activities.

  9. Crustal deformation study in the Canary Archipelago by the analysis of GPS observations

    NASA Astrophysics Data System (ADS)

    Martín, Adriana; Sevilla, Miguel; Zurutuza, Joaquín

    2014-06-01

    The Canary Archipelago is an active volcanic region located in the African plate, at 100 Km of the northwest coast of Africa. The Complutense University of Madrid, Institute of Astronomy and Geodesy (CSIC-UCM) and University of Jaén, established a GPS Network in this region and carried out six observations campaigns from 2002 to 2009. The focus of thiswork is processing and analyzing these observations to study the geodynamic behavior of the stations of this network. The data have been computed with the Bernese GPS Software Version 5.0 obtaining individual solutions of coordinates for each session and campaign, the coordinate velocities of the stations and the time series of baselines formed between them. Results show consistency of station velocities compared to behaviour of areas permanent stations and baselines stability. No deformations could be detected.

  10. An Invasive Fish and the Time-Lagged Spread of Its Parasite across the Hawaiian Archipelago

    PubMed Central

    Gaither, Michelle R.; Aeby, Greta; Vignon, Matthias; Meguro, Yu-ichiro; Rigby, Mark; Runyon, Christina; Toonen, Robert J.; Wood, Chelsea L.; Bowen, Brian W.

    2013-01-01

    Efforts to limit the impact of invasive species are frustrated by the cryptogenic status of a large proportion of those species. Half a century ago, the state of Hawai'i introduced the Bluestripe Snapper, Lutjanus kasmira, to O'ahu for fisheries enhancement. Today, this species shares an intestinal nematode parasite, Spirocamallanus istiblenni, with native Hawaiian fishes, raising the possibility that the introduced fish carried a parasite that has since spread to naïve local hosts. Here, we employ a multidisciplinary approach, combining molecular, historical, and ecological data to confirm the alien status of S. istiblenni in Hawai'i. Using molecular sequence data we show that S. istiblenni from Hawai'i are genetically affiliated with source populations in French Polynesia, and not parasites at a geographically intermediate location in the Line Islands. S. istiblenni from Hawai'i are a genetic subset of the more diverse source populations, indicating a bottleneck at introduction. Ecological surveys indicate that the parasite has found suitable intermediate hosts in Hawai'i, which are required for the completion of its life cycle, and that the parasite is twice as prevalent in Hawaiian Bluestripe Snappers as in source populations. While the introduced snapper has spread across the entire 2600 km archipelago to Kure Atoll, the introduced parasite has spread only half that distance. However, the parasite faces no apparent impediments to invading the entire archipelago, with unknown implications for naïve indigenous Hawaiian fishes and the protected Papahānaumokuākea Marine National Monument. PMID:23468894

  11. An invasive fish and the time-lagged spread of its parasite across the Hawaiian archipelago.

    PubMed

    Gaither, Michelle R; Aeby, Greta; Vignon, Matthias; Meguro, Yu-ichiro; Rigby, Mark; Runyon, Christina; Toonen, Robert J; Wood, Chelsea L; Bowen, Brian W

    2013-01-01

    Efforts to limit the impact of invasive species are frustrated by the cryptogenic status of a large proportion of those species. Half a century ago, the state of Hawai'i introduced the Bluestripe Snapper, Lutjanus kasmira, to O'ahu for fisheries enhancement. Today, this species shares an intestinal nematode parasite, Spirocamallanus istiblenni, with native Hawaiian fishes, raising the possibility that the introduced fish carried a parasite that has since spread to naïve local hosts. Here, we employ a multidisciplinary approach, combining molecular, historical, and ecological data to confirm the alien status of S. istiblenni in Hawai'i. Using molecular sequence data we show that S. istiblenni from Hawai'i are genetically affiliated with source populations in French Polynesia, and not parasites at a geographically intermediate location in the Line Islands. S. istiblenni from Hawai'i are a genetic subset of the more diverse source populations, indicating a bottleneck at introduction. Ecological surveys indicate that the parasite has found suitable intermediate hosts in Hawai'i, which are required for the completion of its life cycle, and that the parasite is twice as prevalent in Hawaiian Bluestripe Snappers as in source populations. While the introduced snapper has spread across the entire 2600 km archipelago to Kure Atoll, the introduced parasite has spread only half that distance. However, the parasite faces no apparent impediments to invading the entire archipelago, with unknown implications for naïve indigenous Hawaiian fishes and the protected Papahānaumokuākea Marine National Monument.

  12. A comprehensive investigation of mesophotic coral ecosystems in the Hawaiian Archipelago.

    PubMed

    Pyle, Richard L; Boland, Raymond; Bolick, Holly; Bowen, Brian W; Bradley, Christina J; Kane, Corinne; Kosaki, Randall K; Langston, Ross; Longenecker, Ken; Montgomery, Anthony; Parrish, Frank A; Popp, Brian N; Rooney, John; Smith, Celia M; Wagner, Daniel; Spalding, Heather L

    2016-01-01

    Although the existence of coral-reef habitats at depths to 165 m in tropical regions has been known for decades, the richness, diversity, and ecological importance of mesophotic coral ecosystems (MCEs) has only recently become widely acknowledged. During an interdisciplinary effort spanning more than two decades, we characterized the most expansive MCEs ever recorded, with vast macroalgal communities and areas of 100% coral cover between depths of 50-90 m extending for tens of km(2) in the Hawaiian Archipelago. We used a variety of sensors and techniques to establish geophysical characteristics. Biodiversity patterns were established from visual and video observations and collected specimens obtained from submersible, remotely operated vehicles and mixed-gas SCUBA and rebreather dives. Population dynamics based on age, growth and fecundity estimates of selected fish species were obtained from laser-videogrammetry, specimens, and otolith preparations. Trophic dynamics were determined using carbon and nitrogen stable isotopic analyses on more than 750 reef fishes. MCEs are associated with clear water and suitable substrate. In comparison to shallow reefs in the Hawaiian Archipelago, inhabitants of MCEs have lower total diversity, harbor new and unique species, and have higher rates of endemism in fishes. Fish species present in shallow and mesophotic depths have similar population and trophic (except benthic invertivores) structures and high genetic connectivity with lower fecundity at mesophotic depths. MCEs in Hawai'i are widespread but associated with specific geophysical characteristics. High genetic, ecological and trophic connectivity establish the potential for MCEs to serve as refugia for some species, but our results question the premise that MCEs are more resilient than shallow reefs. We found that endemism within MCEs increases with depth, and our results do not support suggestions of a global faunal break at 60 m. Our findings enhance the scientific

  13. High-resolution modelling of 3D hydrodynamics in coastal archipelagos

    NASA Astrophysics Data System (ADS)

    Miettunen, Elina; Tuomi, Laura; Ropponen, Janne; Lignell, Risto

    2016-04-01

    Dynamics of the coastal seas are affected by eutrophication, over-fishing, coastal construction and climate change. To enable the sustainable development of these areas, monitoring and modelling of the state of the sea are needed. The Archipelago Sea, located in the northern part of the semi-enclosed and brackish water Baltic Sea, is one of the most complex coastal areas with over 40 000 small islands and islets. It is also very vulnerable area already heavily stressed with eutrophication. Applicable modelling tools are needed to support the decision making and to provide sufficiently reliable information on the effects of the planned actions on the state of the coastal waters. We used 3D hydrodynamic model COHERENS to model the Archipelago Sea area with high spatial resolution of 0.25 nmi. Boundary conditions for this limited area were provided from coarser resolution, 2 nmi, Baltic Sea grid. In order to evaluate the performance of the high-resolution coastal model implementation a comprehensive measurement dataset was gathered, including hydrographic data from three intensive monitoring stations and several more rarely visited monitoring or research stations. The hydrodynamic model was able to simulate the surface temperature and salinity fields and their seasonal variation with good accuracy in this complex area. The sharp depth gradients typical for this area provided some challenges to the modelling. There was some over mixing and related to too strong vertical currents in the steep slopes of the deeper fault lines. Also the water exchange between the more open sea and coastal areas through narrow channels between the islands is not sufficiently well reproduced with the current resolution, leading to too high bottom temperatures.

  14. Microbiological and mycological beach sand quality in a volcanic environment: Madeira archipelago, Portugal.

    PubMed

    Pereira, Elisabete; Figueira, Celso; Aguiar, Nuno; Vasconcelos, Rita; Vasconcelos, Sílvia; Calado, Graça; Brandão, João; Prada, Susana

    2013-09-01

    Madeira forms a mid-Atlantic volcanic archipelago, whose economy is largely dependent on tourism. There, one can encounter different types of sand beach: natural basaltic, natural calcareous and artificial calcareous. Microbiological and mycological quality of the sand was analyzed in two different years. Bacterial indicators were detected in higher number in 2010 (36.7% of the samples) than in 2011 (9.1%). Mycological indicators were detected in a similar percentage of samples in 2010 (68.3%) and 2011 (75%), even though the total number of colonies detected in 2010 was much higher (827 in 41 samples) than in 2011 (427 in 66 samples). Enterococci and potentially pathogenic and allergenic fungi (particularly Penicillium sp.) were the most common indicators detected in both years. Candida sp. yeast was also commonly detected in the samples. The analysis of the 3rd quartile and maximum numbers of all indicators in samples showed that artificial beaches tend to be more contaminated than the natural ones. However, a significant difference between the variables was lacking. More monitoring data (number of bathers, sea birds, radiation intensity variation, and a greater number of samples) should be collected in order to confirm if these differences are significant. In general, the sand quality in the archipelago's beaches was good. As the sand may be a vector of diseases, an international common set of indicators and values and a compatible methodologies for assessing sand contamination, should be defined, in order to provide the bather's with an indication of beach sand quality, rather than only the water. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Reproductive response to nitrogen and phosphorus fertilization along the Hawaiian archipelago's natural soil fertility gradient.

    PubMed

    DiManno, Nicole M; Ostertag, Rebecca

    2016-01-01

    Nitrogen (N) and phosphorus (P) are the most important nutrients involved in plant reproduction and typically the most limiting in terrestrial ecosystems. The natural soil fertility gradient of the Hawaiian archipelago, in which younger islands are N limited and older islands are P limited, provides a model system to examine questions regarding allocation of nutrients. Using fertilized plots (+N or +P) at the extreme sites of the Hawaiian archipelago, vegetative productivity (e.g., net primary productivity, growth, and litterfall) and foliar nutrient responses have previously been studied for the dominant canopy tree, Metrosideros polymorpha. Here, we investigated whether the reproductive response of M. polymorpha mirrors the previously found vegetative productivity and foliar nutrient responses, by quantifying: (1) inflorescence and seed productivity, and (2) nutrient concentration of reproductive structures. Fertilization with N and P did not significantly affect the productivity of inflorescences or seeds, or seed viability at either site. However, nutrient concentrations increased after fertilization; %P increased in inflorescences in the +P treatment at the P-limited site. Seeds and inflorescences generally contained higher nutrient concentrations than leaves at both sites. Unlike foliar data, reproductive strategies of M. polymorpha differed depending on soil nutrient limitation with emphasis on quality (higher seed viability/greater nutrient concentrations) at the P-limited site. We suggest that in response to P additions M. polymorpha employs a nutrient conservation strategy for its inflorescences and an investment strategy for its seeds. Examining N and P simultaneously challenges a basic assumption that reproductive allocation follows a similar pattern to the often measured aboveground productivity.

  16. A comprehensive investigation of mesophotic coral ecosystems in the Hawaiian Archipelago

    PubMed Central

    Boland, Raymond; Bolick, Holly; Bowen, Brian W.; Bradley, Christina J.; Kane, Corinne; Kosaki, Randall K.; Langston, Ross; Longenecker, Ken; Montgomery, Anthony; Parrish, Frank A.; Popp, Brian N.; Smith, Celia M.; Wagner, Daniel; Spalding, Heather L.

    2016-01-01

    Although the existence of coral-reef habitats at depths to 165 m in tropical regions has been known for decades, the richness, diversity, and ecological importance of mesophotic coral ecosystems (MCEs) has only recently become widely acknowledged. During an interdisciplinary effort spanning more than two decades, we characterized the most expansive MCEs ever recorded, with vast macroalgal communities and areas of 100% coral cover between depths of 50–90 m extending for tens of km2 in the Hawaiian Archipelago. We used a variety of sensors and techniques to establish geophysical characteristics. Biodiversity patterns were established from visual and video observations and collected specimens obtained from submersible, remotely operated vehicles and mixed-gas SCUBA and rebreather dives. Population dynamics based on age, growth and fecundity estimates of selected fish species were obtained from laser-videogrammetry, specimens, and otolith preparations. Trophic dynamics were determined using carbon and nitrogen stable isotopic analyses on more than 750 reef fishes. MCEs are associated with clear water and suitable substrate. In comparison to shallow reefs in the Hawaiian Archipelago, inhabitants of MCEs have lower total diversity, harbor new and unique species, and have higher rates of endemism in fishes. Fish species present in shallow and mesophotic depths have similar population and trophic (except benthic invertivores) structures and high genetic connectivity with lower fecundity at mesophotic depths. MCEs in Hawai‘i are widespread but associated with specific geophysical characteristics. High genetic, ecological and trophic connectivity establish the potential for MCEs to serve as refugia for some species, but our results question the premise that MCEs are more resilient than shallow reefs. We found that endemism within MCEs increases with depth, and our results do not support suggestions of a global faunal break at 60 m. Our findings enhance the scientific

  17. Barotropic Hydrodynamics at high Frequency around the archipelago of Saint Pierre and Miquelon

    NASA Astrophysics Data System (ADS)

    Bezaud, Marion; Lazure, Pascal; Le Cann, Bernard

    2017-04-01

    The Saint Pierre and Miquelon (SPM) archipelago is located on the western border of the Newfoundland Grand Banks (GB). This region is an area of great ecological and economic interests. However, hydrodynamical conditions remains poorly known. Current and Temperature/Salinity measurements have been recently performed around SPM. Strong diurnal currents in the depth averaged speeds with the period of O1 (25.95 h) have been observed. This diurnal period is noticeable because the main tidal components in the archipelago are dominantly semi diurnal. However, a diurnal anomaly has already been described circulating around the Grand Bank, especially on the Eastern part of the Bank. In addition, oscillations in the barotropic current are observed with an unusual period of two days. They can reach 50 cm s-1, which is larger than the effect of the tide. These oscillations are not permanent, but last during a few days after a meteorological wind event. After presenting these unique observations, this study focuses on the understanding the hydrodynamic processes related to these two oscillating phenomena. Is it possible to relate the diurnal and two day period currents to the dynamics on the whole GB? What is the importance of the local dynamics? To answer these questions, a 2 km regional model has been implemented in the region of the Gulf of Saint Lawrence, Nova Scotia, Newfoundland and SPM. The two dimensional horizontal model was running with tide and/or wind and atmospheric surface pressure forcings. The impact of the wind and of the barotropic tide at a local scale has then been studied. Model results were validated using in-situ and tidal gauges data. These simulations allow exploring and characterizing the processes explaining these diurnal and two day oscillations around SPM and their spatial distribution on the Grand Banks.

  18. Reconstructing decades of glacial mass loss in the Canadian Arctic Archipelago

    NASA Astrophysics Data System (ADS)

    Noël, Brice; van de Berg, Willem Jan; Lhermitte, Stef; Wouters, Bert; van den Broeke, Michiel

    2017-04-01

    The Canadian Arctic Archipelago (CAA) comprises multiple small glaciers and ice caps mostly concentrated on Ellesmere and Baffin Islands situated in the north (NCAA) and south (SCAA) of the archipelago, respectively. Because they cover a relatively small area and show complex geometries, current regional climate models, generally running at 5 to 20 km horizontal resolution, struggle to accurately resolve surface mass change patterns. Here, we present a 58-year (1958-2015) reconstruction of daily, 1 km surface mass balance (SMB) of the CAA, statistically downscaled from the output of the regional climate model RACMO2.3 at 11 km. By correcting for biases in elevation and ice albedo, the downscaling method significantly improves mass loss estimates over narrow outlet glaciers and isolated ice fields through better resolved marginal meltwater runoff. During the last two decades, CAA glaciers have experienced warmer conditions (+1.1°C) resulting in continued mass loss. NCAA and SCAA mass loss accounted for -24.7 ± 18.0 Gt yr-1 and -21.9 ± 8.2 Gt yr-1 respectively, almost tripling (-8.4 Gt yr-1) and doubling (-11.8 Gt yr-1) the 1958-1995 average. Following the recent warming, enhanced meltwater production reduced the refreezing capacity of inland firn layers by about 6%. While the interior of NCAA ice caps can still buffer most of the additional melt, the lack of a perennial firn area over low-lying SCAA glaciers caused uninterrupted mass loss since the 1980s, which, in the absence of significant refreezing capacity, indicates inevitable disappearance of these highly sensitive glaciers.

  19. Climate change impacts on wildlife in a High Arctic archipelago - Svalbard, Norway.

    PubMed

    Descamps, Sébastien; Aars, Jon; Fuglei, Eva; Kovacs, Kit M; Lydersen, Christian; Pavlova, Olga; Pedersen, Åshild Ø; Ravolainen, Virve; Strøm, Hallvard

    2017-02-01

    The Arctic is warming more rapidly than other region on the planet, and the northern Barents Sea, including the Svalbard Archipelago, is experiencing the fastest temperature increases within the circumpolar Arctic, along with the highest rate of sea ice loss. These physical changes are affecting a broad array of resident Arctic organisms as well as some migrants that occupy the region seasonally. Herein, evidence of climate change impacts on terrestrial and marine wildlife in Svalbard is reviewed, with a focus on bird and mammal species. In the terrestrial ecosystem, increased winter air temperatures and concomitant increases in the frequency of 'rain-on-snow' events are one of the most important facets of climate change with respect to impacts on flora and fauna. Winter rain creates ice that blocks access to food for herbivores and synchronizes the population dynamics of the herbivore-predator guild. In the marine ecosystem, increases in sea temperature and reductions in sea ice are influencing the entire food web. These changes are affecting the foraging and breeding ecology of most marine birds and mammals and are associated with an increase in abundance of several temperate fish, seabird and marine mammal species. Our review indicates that even though a few species are benefiting from a warming climate, most Arctic endemic species in Svalbard are experiencing negative consequences induced by the warming environment. Our review emphasizes the tight relationships between the marine and terrestrial ecosystems in this High Arctic archipelago. Detecting changes in trophic relationships within and between these ecosystems requires long-term (multidecadal) demographic, population- and ecosystem-based monitoring, the results of which are necessary to set appropriate conservation priorities in relation to climate warming.

  20. Origin and in situ diversification in Hemidactylus geckos of the Socotra Archipelago.

    PubMed

    Gómez-Díaz, Elena; Sindaco, Roberto; Pupin, Fabio; Fasola, Mauro; Carranza, Salvador

    2012-08-01

    The Socotra Archipelago is an ancient continental fragment of Gondwanan origin and one of the most isolated landforms on Earth and a biodiversity hot spot. Yet, the biogeography and evolutionary history of its endemic fauna still remain largely overlooked. We investigate the origin, tempo and mode of diversification in the Hemidactylus geckos of the Socotra Archipelago. Concatenated and multilocus species coalescent analyses of Hemidactylus from Arabia and North Africa indicate that the Hemidactylus from Socotra do not form a monophyletic group and branch as three independent and well-supported clades instead. Both the chronogram inferred using the gene tree approach of BEAST and the age-calibrated multilocus species tree obtained using *BEAST suggest that the origin of Hemidactylus from Socotra may have involved a first vicariance event that occurred in the Early Miocene, followed by two independent transoceanic dispersal events that occurred more recently, during the Pliocene. Within Socotra, we analysed patterns of genetic diversity, the phylogeography and the demographic history in all seven nonintroduced species of Hemidactylus. Results based on two mitochondrial and two nuclear loci from 144 individuals revealed complex patterns of within-island diversification and high levels of intra-species genetic divergence. The interplay of both historical and ecological factors seems to have a role in the speciation process of this group of geckos. Interestingly, the case of H. forbesii and H. oxyrhinus, which inhabit the island of Abd al Kuri with an area of 133 km(2), may represent one of the most extreme cases of intra-island speciation in reptiles ever reported. © 2012 Blackwell Publishing Ltd.

  1. Benthic Habitat Mapping and Biodiversity Analysis in the Primeiras and Segundas Archipelago Reserve

    NASA Astrophysics Data System (ADS)

    Teixeira, L.; Nilsson, M.; Hedley, J.; Shapiro, A.

    2015-04-01

    The Primeiras and Segundas Archipelago Reserve is a recently established marine protected area, the largest in Africa, located in the waters of Northern Mozambique. This protected area is of significant local economic importance and global ecological relevance, containing the southernmost coral reefs in Eastern Africa. However, information related to the marine ecosystem, notably benthic habitat is very scarce. Twelve atolls were mapped in the region using object-based image classification of very-high resolution satellite imagery (IKONOS, Quickbird, and WorldView-2). Geographically referenced data on benthic cover and depth were gathered in the course of three fieldwork expeditions covering a total of four atolls and two shallow reef structures in the Segundas Archipelago. The resulting map allows the estimation of three distinct types of coral cover (field, patches, spurs and grooves); the differentiation of sand, rubble and rock substrate; and the detection of seagrass and brown macroalgae, identifying up to 24 benthic habitats. Average overall accuracy was above 50%. The high variability of the optical properties on the reef systems, in large due to the connectivity with the mainland via plumes, while interesting from an ecological perspective increases the challenges for remote sensing of bottom cover. New information indicates the presence of deep benthic cover extending from the atolls, suggesting the need for further research on Coastal Eastern African corals, namely on their resilience and connectivity, and supporting current knowledge of the existence of an almost continuous coral reef from Kenya to Mozambique. Coral and fish biodiversity data have been analysed together with the satellite-derived maps. Results support the local perception that ecosystems are in decline and uncover new information about biodiversity's spatial patterns. Our work provides a detailed depiction of marine habitats that may aid the management of the protected area, namely in

  2. Unexpectedly high radioactivity burdens in ice-rafted sediments from the Canadian Arctic Archipelago.

    PubMed

    Cota, Glenn F; Cooper, Lee W; Darby, Dennis A; Larsen, I L

    2006-07-31

    Unexpectedly high specific activities of (137)Cs (1800-2000 Bq kg(-1) dry weight) have been detected in fine-grained sediments entrained in multi-year sea ice floes grounded in Resolute Bay near the center of the Northwest Passage through the Canadian Arctic Archipelago. These results are remarkable because: (1) the specific activities are about two orders of magnitude higher than average specific activities detected in previous studies of sea ice rafted sediments from the Arctic Ocean, (2) two independent observations of these unexpectedly high specific activities were made several years apart, (3) the sampling site is on the opposite side of the Arctic basin from potential radioactive sources such as disposal and weapons testing sites of the former Soviet Union and nuclear fuel reprocessing sites in western Europe, and (4) the closest compositional match to known geologic source regions is Banks Island, on the western edge of the Arctic Archipelago, although a smaller number of grains from one of the two samples were mineralogically matched to sediments in the Laptev Sea. Consequently, the sediments are probably not from a single distinct source and were likely mixed during sea ice transport. Coupled with previous observations of higher radionuclide specific activities in some sea ice rafted sediments relative to bottom sediments, these new observations indicate that comparatively high as well as variable radioactive contaminant burdens in ice rafted sediments must be common and geographically independent of proximity to known contaminant sources. The mechanisms that would facilitate these unexpected high radionuclide burdens in sea ice are not known and require additional study, as well as investigations of the implications for the transport and fate of contaminants in Arctic sea ice.

  3. Living on the edge: Conservation genetics of seven thermophilous plant species in a High Arctic archipelago.

    PubMed

    Birkeland, Siri; Elisabeth Borgen Skjetne, Idunn; Krag Brysting, Anne; Elven, Reidar; Greve Alsos, Inger

    2017-01-20

    Small, isolated, and/or peripheral populations are expected to harbour low levels of genetic variation and may therefore have reduced adaptability to environmental change, including climate warming. In the Arctic, global warming has already caused vegetation change across the region and is acting as a significant stressor on Arctic biodiversity. Many of the rare plants in the Arctic are relicts from early Holocene warm periods, but their ability to benefit from the current warming is dependent on the viability of their populations. We therefore examined Amplified Fragment Length Polymorphism (AFLP) data from regional red listed vascular plant species in the High Arctic archipelago of Svalbard and reference populations from the main distribution area of: 1) Botrychium lunaria, 2) Carex capillaris ssp. fuscidula, 3) Comastoma tenellum, 4) Kobresia simpliciuscula ssp. subholarctica, 5) Ranunculus wilanderi, 6) Sibbaldia procumbens and 7) Tofieldia pusilla In addition, we gathered population size data in Svalbard. The Svalbard populations had low genetic diversity and distinctiveness and few or no private markers compared to populations outside the archipelago. This is similar to observations in other rare species in Svalbard and the genetic depletion may be due to an initial founder effect and/or a genetic bottleneck caused by late Holocene cooling. There seems to be limited gene flow from other areas and the Svalbard populations should therefore be considered as demographically independent management units. Overall, these management units have small and/or few populations and are therefore prone to stochastic events which may further increase vulnerability to inbreeding depression, loss of genetic variation, and reduced evolutionary potential. Our results support theory predicting lower levels of genetic diversity in small, isolated and/or peripheral populations and may be of importance for management of other rare plant species in the Arctic.

  4. New evidence from the western Canadian Arctic Archipelago for the resubmergence of Bering Strait

    NASA Astrophysics Data System (ADS)

    England, John H.; Furze, Mark F. A.

    2008-07-01

    Widespread molluscan samples were collected from raised marine sediments to date the last retreat of the NW Laurentide Ice Sheet from the western Canadian Arctic Archipelago. At the head of Mercy Bay, northern Banks Island, deglacial mud at the modern coast contains Hiatella arctica and Portlandia arctica bivalves, as well as Cyrtodaria kurriana, previously unreported for this area. Multiple H. arctica and C. kurriana valves from this site yield a mean age of 11.5 14C ka BP (with 740 yr marine reservoir correction). The occurrence of C. kurriana, a low Arctic taxon, raises questions concerning its origin, because evidence is currently lacking for a molluscan refugium in the Arctic Ocean during the last glacial maximum. Elsewhere, the oldest late glacial age available on C. kurriana comes from the Laptev Sea where it is < 10.3 14C ka BP and attributed to a North Atlantic source. This is 2000 cal yr younger than the Mercy Bay samples reported here, making the Laptev Sea, ~ 3000 km to the west, an unlikely source. An alternate route from the North Atlantic into the Canadian Arctic Archipelago was precluded by coalescent Laurentide, Innuitian and Greenland ice east of Banks Island until ~ 10 14C ka BP. We conclude that the presence of C. kurriana on northern Banks Island records migration from the North Pacific. This requires the resubmergence of Bering Strait by 11.5 14C ka BP, extending previous age determinations on the reconnection of the Pacific and Arctic oceans by up to 1000 yr. This renewed ingress of Pacific water likely played an important role in re-establishing Arctic Ocean surface currents, including the evacuation of thick multi-year sea ice into the North Atlantic prior to the Younger Dryas geochron.

  5. Fishery of the Green Jack Caranx caballus (Osteichytes: Carangidae) in Las Perlas Archipelago, Pacific Panama.

    PubMed

    Mair, James M; Cipriani, Roberto; Guzman, Hector M; Usan, David

    2012-09-01

    Green Jacks, Caranx caballus, are distributed along the Eastern Pacific coast. In Panama, C. caballus was heavily fished around Las Perlas Archipelago to sustain local markets until 2007, when the archipelago was declared a marine protected area. This first study in Panama, analyzed a sample of 4 990 individuals from Las Perlas, obtained monthly from June 2005 to June 2006, from landings at the central fish market. Average total length was 36.1 +/- 6.4cm and optimum length 38.9cm. Approximately 68% of fish lengths were within +/-10% of the optimal length but only six (15%) were considered mega-spawners. The von Bertalanffy parameters describe a long-lived and fast growing species, while mortality rates revealed that C. caballus is under high fishing pressure. Standard length at which half of the population is mature was 38.8cm, and the size at which individuals matured massively, 33cm. Only 10-13% of the fish were immature. C. caballus reproduces two to three times per year, with peaks in December, April, and probably September, and recruits to the population at least twice per year. Catch per unit effort (CPUE) was best predicted by minimum annual values of the Multivariate ENSO/LNSO Index (MEI) (R2=0.54). Results show that C. caballus in Pacific Panama is overfished. We recommend the raising of the minimum capture/landing size of this species in order to increase the proportion of mega-spawners in the population and guarantee the sustainability of this resource.

  6. Genetic Tests for Ecological and Allopatric Speciation in Anoles on an Island Archipelago

    PubMed Central

    Johansson, Helena

    2010-01-01

    From Darwin's study of the Galapagos and Wallace's study of Indonesia, islands have played an important role in evolutionary investigations, and radiations within archipelagos are readily interpreted as supporting the conventional view of allopatric speciation. Even during the ongoing paradigm shift towards other modes of speciation, island radiations, such as the Lesser Antillean anoles, are thought to exemplify this process. Geological and molecular phylogenetic evidence show that, in this archipelago, Martinique anoles provide several examples of secondary contact of island species. Four precursor island species, with up to 8 mybp divergence, met when their islands coalesced to form the current island of Martinique. Moreover, adjacent anole populations also show marked adaptation to distinct habitat zonation, allowing both allopatric and ecological speciation to be tested in this system. We take advantage of this opportunity of replicated island coalescence and independent ecological adaptation to carry out an extensive population genetic study of hypervariable neutral nuclear markers to show that even after these very substantial periods of spatial isolation these putative allospecies show less reproductive isolation than conspecific populations in adjacent habitats in all three cases of subsequent island coalescence. The degree of genetic interchange shows that while there is always a significant genetic signature of past allopatry, and this may be quite strong if the selection regime allows, there is no case of complete allopatric speciation, in spite of the strong primae facie case for it. Importantly there is greater genetic isolation across the xeric/rainforest ecotone than is associated with any secondary contact. This rejects the development of reproductive isolation in allopatric divergence, but supports the potential for ecological speciation, even though full speciation has not been achieved in this case. It also explains the paucity of anole species

  7. The terrestrial reptile fauna of the Abrolhos Archipelago: species list and ecological aspects.

    PubMed

    Rocha, C F D; Dutra, G F; Vrcibradic, D; Menezes, V A

    2002-05-01

    We have studied the terrestrial reptile fauna of the Abrolhos Archipelago (a group of five islands located ca. 70 km off the southern coast of the State of Bahia, Brazil) and analyze here some of its ecological aspects such as diet, thermal ecology, activity, and some reproductive parameters. Three lizards comprise the archipelago's terrestrial reptile fauna: Tropidurus torquatus (Tropiduridae), Mabuya agilis (Scincidae), and Hemidactylus mabouia (Gekkonidae). The first two are diurnal and the latter is crepuscular/nocturnal (initiating activity at ca. 17:30). The activity period of T. torquatus extended from 5:30 to 18:30 h. Mean field body temperatures of active T. torquatus, M. agilis, and H. mabouia were, respectively, 34.0 +/- 3.7 degrees C (range 23.8-38.0 degrees C; N = 75), 34.5 +/- 2.2 degrees C (range 30.8-37.0 degrees C; N = 6), and 26.3 +/- 1.1 degrees C (range 24.8-28.0 degrees C; N = 8). The predominant prey items in the diet of T. torquatus were ants, coleopterans, and hemipterans. In the diet of M. agilis, coleopterans were the most frequent prey items. For H. mabouia, the most important dietary items were orthopterans. Clutch size of T. torquatus averaged 4.1 +/- 1.1 (range 2-6; N = 15) and was significantly related to female size (R2 = 0.618; p = 0.001; N = 15). Clutch size for H. mabouia was fixed (two) and mean litter size of the viviparous M. agilis was 3.3 +/- 0.6 (range 3-4; N = 3). Tropidurus torquatus and H. mabouia deposit their eggs under rocks in the study area, with the former burying them but not the latter; in both species, more than one female often oviposit under the same rock.

  8. Health Beliefs and Perceptions of Trachoma in Communities on the Bijagos Archipelago of Guinea Bissau

    PubMed Central

    Thompson, Katie; Hutchins, Harry; Baio, Aramata; Cassama, Eunice; Nabicassa, Meno; Bailey, Robin; Last, Anna R.

    2015-01-01

    ABSTRACT Purpose: The World Health Organization aims to eliminate blinding trachoma by 2020 using the SAFE strategy: Surgery for trichiasis, Antibiotics, Facial cleanliness and Environmental improvement. Trachoma is hyperendemic on the remote Bijagos Archipelago of Guinea-Bissau, West Africa. Sociocultural factors remain unexplored here, despite their potential impact on disease control, particularly through the “F” and “E” aspects. By examining these, we aim to illuminate this population's unreported health beliefs, hygiene behaviors and disease perceptions. This understanding will help to optimize future public health interventions, and guide the distribution of limited healthcare resources. Methods: Two unmatched interview series were conducted 1 year apart on Bubaque Island in the Bijagos Archipelago; one in rural villages using purposive snowball sampling, the other in a semi-urban settlement, using random-cluster sampling. Interviews were conducted and recorded in Kriolu, the local dialect, by a supervised local field assistant before translation into English for conventional content analysis. Results: Trachoma was unheard of in either series, despite ongoing local trachoma research. A heterogeneous range of disease etiology and preventative measures were suggested, but the importance of hygiene was more widely reported by semi-urban interviewees. Although western medicine was well regarded, traditional practices continued, particularly in the rural populations. Conclusions: Differences in knowledge, beliefs and behaviors were apparent between the two series. Despite widespread rudimentary knowledge of disease prevention, targeted education might benefit both communities, particularly basic hygiene education for rural communities. Healthcare access should also be improved for rural populations. The impact of these measures could be assessed by future fieldwork. PMID:26158577

  9. Defining Boundaries for Ecosystem-Based Management: A Multispecies Case Study of Marine Connectivity across the Hawaiian Archipelago

    PubMed Central

    Toonen, Robert J.; Andrews, Kimberly R.; Baums, Iliana B.; Bird, Christopher E.; Concepcion, Gregory T.; Daly-Engel, Toby S.; Eble, Jeff A.; Faucci, Anuschka; Gaither, Michelle R.; Iacchei, Matthew; Puritz, Jonathan B.; Schultz, Jennifer K.; Skillings, Derek J.; Timmers, Molly A.; Bowen, Brian W.

    2014-01-01

    Determining the geographic scale at which to apply ecosystem-based management (EBM) has proven to be an obstacle for many marine conservation programs. Generalizations based on geographic proximity, taxonomy, or life history characteristics provide little predictive power in determining overall patterns of connectivity, and therefore offer little in terms of delineating boundaries for marine spatial management areas. Here, we provide a case study of 27 taxonomically and ecologically diverse species (including reef fishes, marine mammals, gastropods, echinoderms, cnidarians, crustaceans, and an elasmobranch) that reveal four concordant barriers to dispersal within the Hawaiian Archipelago which are not detected in single-species exemplar studies. We contend that this multispecies approach to determine concordant patterns of connectivity is an objective and logical way in which to define the minimum number of management units and that EBM in the Hawaiian Archipelago requires at least five spatially managed regions. PMID:25505913

  10. De-facto marine protection from a Navy bombing range: Farallon De Medinilla, Mariana Archipelago, 1997 to 2012.

    PubMed

    Smith, Stephen H; Marx, Donald E

    2016-01-15

    Fourteen surveys were conducted at Farallon De Medinilla (a U.S. Department of Defense bombing range in the Mariana Archipelago) between 1997 and 2012; annual surveys were conducted from 1999 through 2012. There was no evidence that the condition of the biological resources assessed had changed, or been adversely impacted to a significant degree by the training activities being conducted there. Restricted access has resulted in a de-facto preserve effect and outweighs minor negative impacts from training. The health, abundance and biomass of fishes, corals and other marine resources are comparable to or superior to those in similar habitats at other locations within the Mariana Archipelago. Our research suggests that the greatest threat to FDM's marine resources is from fishermen, not military training activities.

  11. Ice mass loss in Greenland, the Gulf of Alaska, and the Canadian Archipelago: Seasonal cycles and decadal trends

    NASA Astrophysics Data System (ADS)

    Harig, Christopher; Simons, Frederik J.

    2016-04-01

    Over the past several decades mountain glaciers and ice caps have been significant contributors to sea level rise. Here we estimate the ice mass changes in the Canadian Archipelago, the Gulf of Alaska, and Greenland since 2003 by analyzing time-varying gravimetry data from the Gravity Recovery and Climate Experiment. Prior to 2013, interannual ice mass variability in the Gulf of Alaska and in regions around Greenland remains within the average estimated over the whole data span. Beginning in summer 2013, ice mass in regions around Greenland departs positively from its long-term trend. Over Greenland this anomaly reached almost 500 Gt through the end of 2014. Overall, long-term ice mass loss from Greenland and the Canadian Archipelago continues to accelerate, while losses around the Gulf of Alaska region continue but remain steady with no significant acceleration.

  12. Paraliparis hawaiiensis, a new species of snailfish (Scorpaeniformes: Liparidae) and the first described from the Hawaiian Archipelago.

    PubMed

    Stein, D L; Drazen, J C

    2014-05-01

    Paraliparis hawaiiensis n.sp. is described from the north-western Hawaiian Islands from two specimens collected at 2196 and 3055 m. It differs from other North Pacific Ocean species in its chin pore arrangement, tooth pattern and body proportions. Although liparid specimens have previously been collected from Hawaii, they were undescribed and are now lost. Therefore, this is the first liparid species described from the archipelago. In situ photographs of Hawaiian snailfishes are also shown and discussed here.

  13. Bionomics of the mud lobster-hole mosquito Aedes (Geoskusea) baisasi in the mangrove swamps of the Ryukyu Archipelago, Japan.

    PubMed

    Toma, Takako; Miyagi, Ichiro; Tamashiro, Mikako; Higa, Yukiko; Okudo, Haruo; Okazawa, Takao

    2011-09-01

    The bionomics of the mud lobster-hole mosquito Aedes (Geoskusea) baisasi in the Ryukyu Archipelago, Japan, was studied in the field and in the laboratory. The studies included the natural habitat, seasonal appearance, flight activity, mating behavior, resistance of eggs to desiccation, and breeding periods of the immature stages of this species. The burrow systems made by the mud lobster Thalassina anomala were excellent as breeding and resting habitats for both the immature and adult stages of the mosquito.

  14. Description of a sexually dimorphic oribatid mite (Arachnida: Acari: Oribatida) from canopy habitats of the Ryukyu Archipelago, southwestern Japan.

    PubMed

    Karasawa, Shigenori; Behan-Pelletier, Valerie

    2007-10-01

    A new species in the monotypic genus Symbioribates, S. aokii sp. nov., is described on the basis of adult material collected from canopy habitats and wind traps in the Ryukyu Archipelago, southwestern Japan. Symbioribates aokii sp. nov. expresses different dimorphism in the octotaxic system from that of the type species, S. papuensis Aoki, 1966. The characteristics of this genus and its relationships to others of the superfamily Oripodoidea are discussed and a revised diagnosis of the family is given.

  15. Public health implications of an outbreak of rabies in arctic foxes and reindeer in the Svalbard archipelago, Norway, September 2011.

    PubMed

    Macdonald, E; Handeland, K; Blystad, H; Bergsaker, M; Fladberg, M; Gjerset, B; Nilsen, O; Os, H; Sandbu, S; Stokke, E; Vold, L; Ørpetveit, I; Gaup Amot, H; Tveiten, O

    2011-10-06

    Between 16 September and 5 October 2011 rabies was diagnosed in two arctic foxes and eight reindeer in the Svalbard archipelago, in Norway. This outbreak occurs at the end of the reindeer hunting season and poses an increased risk to many people that were involved in the hunt. As of 28 September 2011, 280 people had received post-exposure prophylaxis. No human cases of rabies have occurred.

  16. Noble gas tracers of mantle processes beneath the Galápagos archipelago (Invited)

    NASA Astrophysics Data System (ADS)

    Kurz, M. D.; Harpp, K. S.; Geist, D.; Fornari, D. J.; Curtice, J.; Lott, D. E.; Jenkins, W. J.

    2010-12-01

    Recent measurements in dredged glassy basalts from the western and northern submarine edges of the Galápagos archipelago (R/V Revelle/Drift04 and R/V Melville/MV1007 expeditions, respectively) allow a new examination of the spatial distribution of the noble gas isotopic compositions. The large dynamic range in helium isotopic compositions (6.5 to 30 times atmosphere (Ra)) coupled with the spatial distribution of recent submarine and subaerial volcanism provides a unique picture of mantle dynamics. The highest 3He/4He in the Galápagos are found in basalts from Fernandina volcano at the western edge of the archipelago, which also has the most unradiogenic neon isotopic compositions, suggesting that Fernandina lies above the hotspot center. The high helium isotopic signal drops off asymmetrically to the north and south of Fernandina, with higher 3He/4He ratios found to the South, ranging from 10 to 20 Ra near Cerro Azul, Sierra Negra, and Floreana. To the north of Fernandina, 3He/4He ratios decrease rapidly, reaching values close to MORB at Volcan Ecuador (9.8 to 11.4 Ra), Volcan Wolf (8.1 to 9.2 Ra), and Roca Redonda (7.6 to 9.5 Ra). Preliminary data suggests that He, Ne, and Ar isotopes are correlated in basalts from the western edge of the Galápagos. Using neon isotope data to correct 40Ar/36Ar for atmospheric influence shows that 3He/4He is negatively correlated with (extrapolated) 40Ar/36Ar, and strongly suggests that the noble gas variations relate to mantle source, which has important implications for deep earth noble gas budgets. New data from seamounts in the area between the Galápagos Spreading Center (GSC) and the main archipelago reveal relatively small hotspot helium contributions. The region between the GSC and Isla Pinta is characterized by 3He/4He close to MORB (7.3 to 7.7 Ra). The only evidence of hotspot helium contributions is observed at the southernmost end of the Wolf Darwin Lineament (9.3 Ra) and at the shoal between Genovesa and Marchena (9

  17. Exploring the new long-term (150 years) precipitation dataset in Azores archipelago

    NASA Astrophysics Data System (ADS)

    Hernández, Armand; Trigo, Ricardo M.; Kutiel, Haim; Valente, Maria A.; Sigró, Javier

    2015-04-01

    Within the scope of the two major international projects of long-term reanalysis for the 20th century coordinated by NOAA (Compo et al. 2011) and ECMWF (Hersbach et al. 2013) the IDL Institute from the University of Lisbon has digitized a large number of long-term stations records from Portugal and former Portuguese Colonies (Stickler et al. 2014). Recently we have finished the digitization of all precipitation values from Ponta Delgada (capital of the Azores archipelago) obtaining an uninterrupted precipitation monthly time series since 1864 and additionally an almost complete corresponding daily precipitation series, with the exception of some years (1864/1872; 1878/1879; 1888/1905; 1931; 1936 and 1938) for which only monthly values are available. Here, we present an annually, seasonally and daily resolution study of the rainfall regime in Ponta Delgada for the last 150 years and the North Atlantic Oscillation (NAO) influence over this precipitation regime. The distribution of precipitation presents an evident seasonal pattern, with a strong difference between the 'rainy season' (November/March) and the 'dry season' (June/August) with very little rainfall. April/May and September/October correspond to the transitional seasons. The mean annual rainfall in Ponta Delgada is approximately 910 mm and is accumulated (on average) in about 120 rainy days. The precipitation regime in Azores archipelago reveals large inter-annual and intra-annual variability and both have increased considerably in the last decades. The entire studied period (1865-2012) shows an increase in the rainfall conditions between a drier earlier period (1865-1938) and a wetter recent period (1939-2012). At daily resolution, we have used an approach based on different characteristics of rain spells (consecutive days with rainfall accumulation) that has been proved to be satisfactory for the analysis of the different parameters related to the rainfall regime (Kutiel and Trigo, 2014). This approach

  18. Size distribution and genetic diversity of the offshore rockfish (Pontinus kuhlii) from three Atlantic archipelagos and seamounts

    NASA Astrophysics Data System (ADS)

    Catarino, Diana; Stefanni, Sergio; Menezes, Gui M.

    2013-12-01

    The offshore rockfish (Pontinus kuhlii) is a widespread demersal fish in the temperate eastern Atlantic. This species inhabits hard bottoms at depths between 100 and 600m and it is an important resource for the Azorean commercial fishing fleet. During several research fishing surveys in the Azores, Madeira and Cape Verde archipelagos diverse biological data on this species were collected. The degree of geographical population differentiation across the three Atlantic archipelagos was examined using two mitochondrial markers, control region (CR) and cytochrome b (cyt b). A total of 44 specimens were sequenced for each marker revealing high haplotypic diversity (CR: Hd=0.9736; cyt b: Hd=0.8520) and low nucleotide diversity (CR: π=0.0171; cyt b: π=0.0059). The sample size from the different subareas was limited but sufficient to reveal that no genetic structure was evident (ΦST=-0.0465 to -0.0224), suggesting the existence of one panmictic population. Despite very different exploitation rates between archipelagos, the size structure of P. kuhlii was very similar and inter-annual variation was also low. Exploitation rates are probably too low to significantly affect the size structure, even in the Azores where the species is a secondary target of the commercial fishery. In the Azores region this species is more abundant on seamounts, however bigger fishes tend to occur on island slope than on seamounts.

  19. Experimental constraints on the origin and evolution of mildly alkalic basalts from the Kerguelen Archipelago, Southeast Indian Ocean

    NASA Astrophysics Data System (ADS)

    Scoates, James S.; Lo Cascio, Mauro; Weis, Dominique; Lindsley, Donald H.

    2006-05-01

    This experimental study examines the role of clinopyroxene fractionation on major element trends and alkalinity variations in mildly alkalic basalts from the Kerguelen Archipelago, Southeast Indian Ocean. Equilibrium crystallization experiments were carried out on a natural basalt (MgO=5 wt.%, alkalinity index=0.10) over a range of pressures (0 1.43 GPa) and water contents (nominally dry to hydrous, 1.2 wt.% H2O) under relatively oxidizing conditions (Δlog FMQ=+1 to +2) at 0 GPa and relatively reducing conditions (Δlog FMQ=0 to 2) at all higher pressures. The hydrous experiments at 0.93 GPa closely reproduce most of the compositional variations in the 24 25 Ma mildly alkalic lavas from the archipelago, which supports a major role for high-Al clinopyroxene fractionation (5 9 wt.% Al2O3) at pressures corresponding to the base of the Northern Kerguelen Plateau (15 20 km). However, clinopyroxene fractionation at depth fails to produce important changes in the alkalinity of the residual melts. The transition from tholeiitic to mildly alkalic basalts on the Kerguelen Archipelago thus reflects primarily changes in melting conditions (lower extents of partial melting at higher pressures), which is related to crustal and lithospheric thickening as distance from the Southeast Indian Ridge increased over time from 43 to 24 Ma.

  20. Genetic diversity of Japanese encephalitis virus isolates obtained from the Indonesian archipelago between 1974 and 1987.

    PubMed

    Schuh, Amy J; Guzman, Hilda; Tesh, Robert B; Barrett, Alan D T

    2013-07-01

    Five genotypes (GI-V) of Japanese encephalitis virus (JEV) have been identified, all of which have distinct geographical distributions and epidemiologies. It is thought that JEV originated in the Indonesia-Malaysia region from an ancestral virus. From that ancestral virus GV diverged, followed by GIV, GIII, GII, and GI. Genotype IV appears to be confined to the Indonesia-Malaysia region, as GIV has been isolated in Indonesia from mosquitoes only, while GV has been isolated on three occasions only from a human in Malaysia and mosquitoes in China and South Korea. In contrast, GI-III viruses have been isolated throughout Asia and Australasia from a variety of hosts. Prior to this study only 13 JEV isolates collected from the Indonesian archipelago had been studied genetically. Therefore the sequences of the envelope (E) gene of 24 additional Indonesian JEV isolates, collected throughout the archipelago between 1974 and 1987, were determined and a series of molecular adaptation analyses were performed. Phylogenetic analysis indicated that over a 14-year time span three genotypes of JEV circulated throughout Indonesia, and a statistically significant association between the year of virus collection and genotype was revealed: isolates collected between 1974 and 1980 belonged to GII, isolates collected between 1980 and 1981 belonged to GIV, and isolates collected in 1987 belonged to GIII. Interestingly, three of the GII Indonesian isolates grouped with an isolate that was collected during the JE outbreak that occurred in Australia in 1995, two of the GIII Indonesian isolates were closely related to a Japanese isolate collected 40 years previously, and two Javanese GIV isolates possessed six amino acid substitutions within the E protein when compared to a previously sequenced GIV isolate collected in Flores. Several amino acids within the E protein of the Indonesian isolates were found to be under directional evolution and/or co-evolution. Conceivably, the tropical climate

  1. Height Connections and Land Uplift Rates in West-Estonian Archipelago

    NASA Astrophysics Data System (ADS)

    Jürgenson, H.; Liibusk, A.; Kall, T.

    2012-04-01

    Land uplift rates are largest in the western part of Estonia. The uplift is due to post-glacial rebound. In 2001-2011, the Estonian national high-precision levelling network was completely renewed and levelled. This was the third precise levelling campaign in the re-gion. The first one had taken place before the Second World War and the second one in the 1950s. The Estonian mainland was connected with the two largest islands (Saaremaa and Hiiumaa) in the west-Estonian archipelago using the water level monitoring (hydrody-namic levelling) method. Three pairs of automatic tide gauges were installed on opposite coasts of each waterway. The tide gauges were equipped with piezoresistive pressure sen-sors. This represented the first use of such kind of equipment in Estonia. The hydrodynamic levelling series span up to two calendar years. Nevertheless, the obtained hydrodynamic levelling results need to be additionally verified using alternative geodetic methods. The obtained results were compared with the previous high-precision levelling data from the 1960s and 1970s. As well, the new Estonian gravimetric geoid model and the GPS survey were used for GPS-levelling. All the three methods were analyzed, and the preliminary results coincided within a 1-2 cm margin. Additionally, the tide gauges on the mainland and on both islands were connected using high-precision levelling. In this manner, three hydrodynamic and three digital levelling height differences formed a closed loop with the length of 250 km. The closing error of the loop was less than 1 cm. Finally, the Fennoscandian post-glacial rebound was determined from repeated levelling as well as from repeated GPS survey. The time span between the two campaigns of the first-order GPS survey was almost 13 years. According to new calculations, the relative land uplift rates within the study area reached up to +2 mm/year. This is an area with a rela-tively small amount of input data for the Nordic models. In addition, a

  2. Integrating paleoecology and genetics of bird populations in two sky island archipelagos

    PubMed Central

    McCormack, John E; Bowen, Bonnie S; Smith, Thomas B

    2008-01-01

    Background Genetic tests of paleoecological hypotheses have been rare, partly because recent genetic divergence is difficult to detect and time. According to fossil plant data, continuous woodland in the southwestern USA and northern Mexico became fragmented during the last 10,000 years, as warming caused cool-adapted species to retreat to high elevations. Most genetic studies of resulting 'sky islands' have either failed to detect recent divergence or have found discordant evidence for ancient divergence. We test this paleoecological hypothesis for the region with intraspecific mitochondrial DNA and microsatellite data from sky-island populations of a sedentary bird, the Mexican jay (Aphelocoma ultramarina). We predicted that populations on different sky islands would share common, ancestral alleles that existed during the last glaciation, but that populations on each sky island, owing to their isolation, would contain unique variants of postglacial origin. We also predicted that divergence times estimated from corrected genetic distance and a coalescence model would post-date the last glacial maximum. Results Our results provide multiple independent lines of support for postglacial divergence, with the predicted pattern of shared and unique mitochondrial DNA haplotypes appearing in two independent sky-island archipelagos, and most estimates of divergence time based on corrected genetic distance post-dating the last glacial maximum. Likewise, an isolation model based on multilocus gene coalescence indicated postglacial divergence of five pairs of sky islands. In contrast to their similar recent histories, the two archipelagos had dissimilar historical patterns in that sky islands in Arizona showed evidence for older divergence, suggesting different responses to the last glaciation. Conclusion This study is one of the first to provide explicit support from genetic data for a postglacial divergence scenario predicted by one of the best paleoecological records in the

  3. Integrating paleoecology and genetics of bird populations in two sky island archipelagos.

    PubMed

    McCormack, John E; Bowen, Bonnie S; Smith, Thomas B

    2008-06-27

    Genetic tests of paleoecological hypotheses have been rare, partly because recent genetic divergence is difficult to detect and time. According to fossil plant data, continuous woodland in the southwestern USA and northern Mexico became fragmented during the last 10,000 years, as warming caused cool-adapted species to retreat to high elevations. Most genetic studies of resulting 'sky islands' have either failed to detect recent divergence or have found discordant evidence for ancient divergence. We test this paleoecological hypothesis for the region with intraspecific mitochondrial DNA and microsatellite data from sky-island populations of a sedentary bird, the Mexican jay (Aphelocoma ultramarina). We predicted that populations on different sky islands would share common, ancestral alleles that existed during the last glaciation, but that populations on each sky island, owing to their isolation, would contain unique variants of postglacial origin. We also predicted that divergence times estimated from corrected genetic distance and a coalescence model would post-date the last glacial maximum. Our results provide multiple independent lines of support for postglacial divergence, with the predicted pattern of shared and unique mitochondrial DNA haplotypes appearing in two independent sky-island archipelagos, and most estimates of divergence time based on corrected genetic distance post-dating the last glacial maximum. Likewise, an isolation model based on multilocus gene coalescence indicated postglacial divergence of five pairs of sky islands. In contrast to their similar recent histories, the two archipelagos had dissimilar historical patterns in that sky islands in Arizona showed evidence for older divergence, suggesting different responses to the last glaciation. This study is one of the first to provide explicit support from genetic data for a postglacial divergence scenario predicted by one of the best paleoecological records in the world. Our results

  4. In-Situ Estimates of tidal mixing in the Indonesian archipelago from multidisciplinary data

    NASA Astrophysics Data System (ADS)

    Koch-Larrouy, Ariane; Atmadipoera, Agus; van Beek, Pieter; Madec, Gurvan; Aucan, Jerome; Lyard, Florent; Grelet, Jacques; Souhaut, Marc

    2015-04-01

    The Indonesian Mixing program (INDOMIX) was designed to quantify the very strong mixing that transforms Pacific waters into homohaline Indonesian Waters in the Indonesian archipelago. The turbulent dissipation rates and associated mixing were estimated and analyzed using a multidisciplinary approach that combines physical and geochemical observations: 1) direct measurements of the dissipation using a microstructure profiler, 2) use of density-based fine-scale methods, and 3) study of the vertical distribution of natural radionuclides (radium isotopes and actinium-227). Data were collected at five contrasting stations within the Indonesian archipelago. Strong instabilities, inversions of the density profiles and a very strong water mass transformation were observed. A wide range of values is obtained for dissipation within [10-10, 10-4] W.kg-1 with spots of higher dissipation in the ocean interior correlated with a strong internal tide signal. Both Fine-scale and micro-scale methods allow us to identify very strong dissipation energy levels above the straits, ranging within [10-7, 10-4] W.kg-1, in contrast to lower values at stations far from generation sites. However, the dissipation in the interior water column for the station located in the center of Halmahera [10-9, 10-8] W.kg-1 is stronger than for the Banda station [10-11, 10-10] W.kg-1, which is further away from generation sites. The three approaches agree relatively well and provide Kz values ranging between 5 10-4 and 5 10-1 m2.s-1, except in the Banda Sea where values are similar to the ones found in the open ocean (10-6 m2.s-1). Kz values mainly increase toward the bottom, where stratification decreases. Surface mixing, at the base of the mixed layer is found to be still very strong with values within [10-4, 10-3 m2.s-1]. These results confirm the results of modelling studies, in which hypothesis of intensified subsurface mixing were made, a mixing that strongly modifies the whole tropical mean state and

  5. Tidal Mixing in the Indonesian Archipelago and Its Impact on Climate

    NASA Astrophysics Data System (ADS)

    Koch-Larrouy, A.; Atmadipoera, A.; Madec, G.; Lengaigne, M.; Terray, P.; Izumo, T.; van Beek, P.

    2014-12-01

    The Indonesian archipelago produces large internal tides dissipation in the thermocline. The recent Indonesian Mixing program (INDOMIX) has been designed to quantify this mixing using direct and indirect measure of the mixing.A wide range of values is obtained for dissipation within [10-8, 10-4] W/kg with spots of higher dissipation in the ocean interior correlated with a strong internal tide signal. Deduced Kz values are found between 510-4 to 5 10-1 m2/s, much more higher than open ocean values. Surface mixing, below the base of the mixed layer is found to be very strong above all straits, with values within [10-4, 10-3 m2/s]. Introduced in a model using an adapted parameterisation to the Indonesian archipelago, models show good agreement with the observations, where strong water mass transformation has been previously diagnosed. This additional mixing produce a ~0.5°C surface cooling and reduces by 20% the overlying deep convection. This improves both the amount and structure of the rainfall and weakens the wind convergence relaxes the equatorial Pacific trade winds and strengthens the winds along Java coast. These wind changes causes the thermocline to be deeper in the eastern equatorial Pacific and shallower in the eastern Indian Ocean. The El Nino Southern Oscillation (ENSO) amplitude is therefore slightly reduced while the Indian Ocean Dipole/Zonal Mode (IODZM) variability increases. IODZM precursors, related to ENSO events the preceding winter in this model, are also shown to be more efficient in promoting an IODZM thanks to an enhanced wind/thermocline coupling. The MJO is also improved in the model.Changes in the coupled system in response tidal mixing are as large as those found when closing the Indonesian Throughflow, emphasizing the key role of IA on the Indo-Pacific climate. This suggests that climate models need to take into account this intensified mixing to properly represent the mean state of the atmosphere and its climate variability.

  6. Genetic Diversity of Japanese Encephalitis Virus Isolates Obtained from the Indonesian Archipelago Between 1974 and 1987

    PubMed Central

    Schuh, Amy J.; Guzman, Hilda; Tesh, Robert B.

    2013-01-01

    Abstract Five genotypes (GI–V) of Japanese encephalitis virus (JEV) have been identified, all of which have distinct geographical distributions and epidemiologies. It is thought that JEV originated in the Indonesia-Malaysia region from an ancestral virus. From that ancestral virus GV diverged, followed by GIV, GIII, GII, and GI. Genotype IV appears to be confined to the Indonesia-Malaysia region, as GIV has been isolated in Indonesia from mosquitoes only, while GV has been isolated on three occasions only from a human in Malaysia and mosquitoes in China and South Korea. In contrast, GI–III viruses have been isolated throughout Asia and Australasia from a variety of hosts. Prior to this study only 13 JEV isolates collected from the Indonesian archipelago had been studied genetically. Therefore the sequences of the envelope (E) gene of 24 additional Indonesian JEV isolates, collected throughout the archipelago between 1974 and 1987, were determined and a series of molecular adaptation analyses were performed. Phylogenetic analysis indicated that over a 14-year time span three genotypes of JEV circulated throughout Indonesia, and a statistically significant association between the year of virus collection and genotype was revealed: isolates collected between 1974 and 1980 belonged to GII, isolates collected between 1980 and 1981 belonged to GIV, and isolates collected in 1987 belonged to GIII. Interestingly, three of the GII Indonesian isolates grouped with an isolate that was collected during the JE outbreak that occurred in Australia in 1995, two of the GIII Indonesian isolates were closely related to a Japanese isolate collected 40 years previously, and two Javanese GIV isolates possessed six amino acid substitutions within the E protein when compared to a previously sequenced GIV isolate collected in Flores. Several amino acids within the E protein of the Indonesian isolates were found to be under directional evolution and/or co-evolution. Conceivably, the

  7. Features of shoreline displacement in the Holocene of Franz josef Land Archipelago

    NASA Astrophysics Data System (ADS)

    Barliaev, A.; Anisimov, M.

    2014-12-01

    Changes in the global sea level after the LGM caused the significant alteration in relation of land and sea in Arctic. The rise of the sea level in Arctic was accompanied with present tectonic processes. Marine terraces are formed with the combination of eustatic sea level fluctuations and glacioisostatic uplift of the territory with the significant role of complicated tectonic block movements. There are nearly about 150 radiocarbon ages data for Franz-Josef Land archipelago now. The represented conclusions are a generalization of the published data and results of our field researches with series of new radiocarbon dates. We managed to collect valuable factual material during the Russian Arctic National Park expedition in 2012. The distinctions of post-glacial rise of different islands and peculiarities of Holocene deglaciation were identified with the help of marine terraces analysis. The altitude of the terraces with the same age on different islands exceeds 15 meters in some cases. However, analysis of the data suggests that the continuous series of raised beaches from 35 m a.s.l. formed during the last 10000 years. It is impossible to build up an univocal model of emergence isobases with the existing data. Alexandra Land Island was the special object of this investigation. The large beach ridge from Lunar Ice Cap to Kropotkina Ice Cap divides the island on two parts. The northern one is covered with marine sediments, whereas the southern - with glaciofluvial sediments with negligible areas of marine sediments. The difference between the terraces' ages of Alexandra Land on the Dezhneva Bay shore and the northern shore of island suggests that: 1) In the early Holocene the rate of the transgression exceeded the tectonic uplift of the territory; 2) Formation of the large central beach ridge occurred near 6700 years ago, the maximum marine limit in the Alexandra Land Island; 3) The rate of the tectonic rise of the territory exceeded the eustatic sea level rise in

  8. Testing the island effect on phenotypic diversification: insights from the Hemidactylus geckos of the Socotra Archipelago

    NASA Astrophysics Data System (ADS)

    Garcia-Porta, Joan; Šmíd, Jiří; Sol, Daniel; Fasola, Mauro; Carranza, Salvador

    2016-04-01

    Island colonization is often assumed to trigger extreme levels of phenotypic diversification. Yet, empirical evidence suggests that it does not always so. In this study we test this hypothesis using a completely sampled mainland-island system, the arid clade of Hemidactylus, a group of geckos mainly distributed across Africa, Arabia and the Socotra Archipelago. To such purpose, we generated a new molecular phylogeny of the group on which we mapped body size and head proportions. We then explored whether island and continental taxa shared the same morphospace and differed in their disparities and tempos of evolution. Insular species produced the most extreme sizes of the radiation, involving accelerated rates of evolution and higher disparities compared with most (but not all) of the continental groups. In contrast, head proportions exhibited constant evolutionary rates across the radiation and similar disparities in islands compared with the continent. These results, although generally consistent with the notion that islands promote high morphological disparity, reveal at the same time a complex scenario in which different traits may experience different evolutionary patterns in the same mainland-island system and continental groups do not always present low levels of morphological diversification compared to insular groups.

  9. A new species of Agelas from the Zanzibar Archipelago, western Indian Ocean (Porifera, Demospongiae)

    PubMed Central

    Manconi, Renata; Pronzato, Roberto; Perino, Erica

    2016-01-01

    Abstract A new sponge species (Demospongiae: Agelasida: Agelasidae) is described from the eastern coast of Unguja Island in the Zanzibar Archipelago. Agelas sansibarica sp. n. is compared to all other Agelas species described so far. The new species differs from its congeners mainly in its three categories of verticillate spicules (acanthostyles, acanthostrongyles, and acanthoxeas) and their sizes. Acanthostrongyles, well represented in the spicular complement, are an exclusive trait of the new species widening the morphological range of the genus. Summarizing on spicular complement and spicular morphotraits of 36 species belonging to the genus Agelas: i) 32 species show only acanthostyles from Indo-Pacific (n = 14), Atlantic (n = 17), and Mediterranean (n = 1); ii) three Indo-Pacific species show acanthostyles and acanthoxeas; iii) one species Agelas sansibarica sp. n. from the western Indian Ocean is characterised by the unique trait of three categories of verticillate spicules (acanthostyles, acanthostrongyles and acanthoxeas). A key for the Indo-Pacific species is supplied together with short descriptions, illustrations, and geographic range; literature on chemical bioprospecting of the genus Agelas is also provided. PMID:26877669

  10. Persistent organic pollutants (POPs) in killer whales (Orcinus orca) from the Crozet Archipelago, southern Indian Ocean.

    PubMed

    Noël, Marie; Barrett-Lennard, Lance; Guinet, Christophe; Dangerfield, Neil; Ross, Peter S

    2009-10-01

    Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs), are ubiquitous environmental contaminants of which significant concentrations are reported in upper trophic level animals. In 1998, we collected blubber biopsy samples (n=11) from killer whales (Orcinus orca) inhabiting the coastal waters around Possession Island, Crozet Archipelago, southern Indian Ocean, for contaminant analyses. Despite inhabiting an isolated region far removed from industrial activities, these killer whales can presently be considered among the most PCB-contaminated cetaceans in the southern hemisphere, with concentrations ranging from 4.4 to 20.5mg/kg lipid weight (lw). PCDD levels ranged from below the detection limit (5 ng/kg) to 77.1 ng/kg lw and PCDF levels from below the detection limit (7 ng/kg) to 36.1 ng/kg lw. Over 70% of our study animals had PCB concentrations which exceeded a 1.3mg/kg PCB threshold established for endocrine disruption and immunotoxicity in free-ranging harbour seals, suggesting that organic contaminants cannot be ruled out as an additional threat to this declining population.

  11. Environmental Factors Affecting Large-Bodied Coral Reef Fish Assemblages in the Mariana Archipelago

    PubMed Central

    Richards, Benjamin L.; Williams, Ivor D.; Vetter, Oliver J.; Williams, Gareth J.

    2012-01-01

    Large-bodied reef fishes represent an economically and ecologically important segment of the coral reef fish assemblage. Many of these individuals supply the bulk of the reproductive output for their population and have a disproportionate effect on their environment (e.g. as apex predators or bioeroding herbivores). Large-bodied reef fishes also tend to be at greatest risk of overfishing, and their loss can result in a myriad of either cascading (direct) or indirect trophic and other effects. While many studies have investigated habitat characteristics affecting populations of small-bodied reef fishes, few have explored the relationship between large-bodied species and their environment. Here, we describe the distribution of the large-bodied reef fishes in the Mariana Archipelago with an emphasis on the environmental factors associated with their distribution. Of the factors considered in this study, a negative association with human population density showed the highest relative influence on the distribution of large-bodied reef fishes; however, depth, water temperature, and distance to deep water also were important. These findings provide new information on the ecology of large-bodied reef fishes can inform discussions concerning essential fish habitat and ecosystem-based management for these species and highlight important knowledge gaps worthy of additional research. PMID:22384014

  12. Antioxidant Capacity, Cytotoxicity and Antimycobacterial Activity of Madeira Archipelago Endemic Helichrysum Dietary and Medicinal Plants

    PubMed Central

    Gouveia-Figueira, Sandra C.; Gouveia, Carla A.; Carvalho, Maria J.; Rodrigues, Ana I.; Nording, Malin L.; Castilho, Paula C.

    2014-01-01

    The potential bioactivity of dietary and medicinal endemic Helichrysum plants from Madeira Archipelago was explored, for the first time, in order to supply new information for the general consumer. In vitro antioxidant properties were investigated using DPPH, ABTS•+, FRAP and β-Carotene assays, and the total phenolic content (TPC) and total flavonoid content (TFC) were also determined. Although the results generally showed a large variation among the three analyzed plants, the methanolic extracts showed the highest antioxidant capacity. Exception is made for H. devium n-hexane extract that showed good radical scavenger capacity associated to compounds with good reducing properties. In the Artemia salina toxicity assay and antimycobaterial activity, H. devium was the most potent plant with the lowest LD50 at 216.7 ± 10.4 and MIC ≤ 50 μg·mL−1. Chemometric evaluation (Principal Component Analysis—PCA) showed close interdependence between the ABTS, TPC and TFC methods and allowed to group H. devium samples. PMID:26785236

  13. Analysis of the bimodal diurnal rainfall pattern during the summer monsoon over the Hong Kong Archipelago

    SciTech Connect

    Welsh, P.T.; Wai, M.M.K.

    1994-12-31

    A complete year`s record of hourly surface measurements was used to examine the atmospheric diurnal secondary circulations over the Hong Kong Archipelago in conjunction with spatial and temporal variations of surface temperature, wind speed and rainfall. The two objectives in this study are to identify both the spatial and temporal variations of diurnal temperature, wind speed and rainfall over the entire Hong Kong area, and to link these variations to the forcing mechanisms and their scales of action. In this way, the authors can establish some useful understanding of the forcing and response, leading toward a systematic method to identify inappropriate parameterization schemes in otherwise potentially useful numerical models. This study focuses on the occurrence of a summer biomodal rainfall maximum which results from the interaction of summer monsoon flow and local mesoscale secondary circulations. The result is a dominant morning rainfall maximum and a secondary afternoon peak. Evidence of atmospheric diurnal secondary circulations are found at 10 local data stations. Though system strength and timing vary, these secondary circulation systems behave like a classic sea breeze circulation, complicated by superimposed slope effects, but dominated by the summer monsoon flow.

  14. Descriptions of two azooxanthellate Palythoa species (Subclass Hexacorallia, Order Zoantharia) from the Ryukyu Archipelago, southern Japan

    PubMed Central

    Irei, Yuka; Sinniger, Frederic; Reimer, James Davis

    2015-01-01

    Abstract Two new species of zoantharians (Hexacorallia, Zoantharia, Sphenopidae), Palythoa mizigama sp. n. and Palythoa umbrosa sp. n., are described from the Ryukyu Archipelago, southern Japan. Unlike almost all other known Palythoa spp., both species are azooxanthellate and inhabit low-light environments such as floors or sides of caves, crevasses, or hollows of shallow coral reefs. The two species were initially considered to be the same species from their similar habitat environments and highly similar morphological features. However, phylogenetic analyses of nuclear internal transcribed spacer (ITS) ribosomal DNA, mitochondrial 16S ribosomal DNA, and cytochrome oxidase subunit I (COI) sequences revealed that these two species have a genetically distant relationship within the genus Palythoa. Morphological characteristics, including polyp size, tentacle number, external/internal coloration, and types and sizes of cnidae were examined in this study. As a result, only tentacle coloration was found to be useful for the morphological distinction between the two species. Palythoa mizigama possesses white tentacles with black horizontal stripes while Palythoa umbrosa possesses white tentacles without any stripe patterns. Considering their distant phylogenetic relationship, it can be assumed that their unique yet similar morphological and ecological characteristics developed independently in each species as an example of parallel evolution. PMID:25685008

  15. AN ADAPTIVE RADIATION OF FROGS IN A SOUTHEAST ASIAN ISLAND ARCHIPELAGO

    PubMed Central

    Blackburn, David C; Siler, Cameron D; Diesmos, Arvin C; McGuire, Jimmy A; Cannatella, David C; Brown, Rafe M

    2013-01-01

    Living amphibians exhibit a diversity of ecologies, life histories, and species-rich lineages that offers opportunities for studies of adaptive radiation. We characterize a diverse clade of frogs (Kaloula, Microhylidae) in the Philippine island archipelago as an example of an adaptive radiation into three primary habitat specialists or ecotypes. We use a novel phylogenetic estimate for this clade to evaluate the tempo of lineage accumulation and morphological diversification. Because species-level phylogenetic estimates for Philippine Kaloula are lacking, we employ dense population sampling to determine the appropriate evolutionary lineages for diversification analyses. We explicitly take phylogenetic uncertainty into account when calculating diversification and disparification statistics and fitting models of diversification. Following dispersal to the Philippines from Southeast Asia, Kaloula radiated rapidly into several well-supported clades. Morphological variation within Kaloula is partly explained by ecotype and accumulated at high levels during this radiation, including within ecotypes. We pinpoint an axis of morphospace related directly to climbing and digging behaviors and find patterns of phenotypic evolution suggestive of ecological opportunity with partitioning into distinct habitat specialists. We conclude by discussing the components of phenotypic diversity that are likely important in amphibian adaptive radiations. PMID:24033172

  16. Ichthyophonus in Puget Sound rockfish from the San Juan Islands archipelago and Puget Sound, Washington, USA

    USGS Publications Warehouse

    Halos, D.; Hart, S.A.; Hershberger, P.; Kocan, R.

    2005-01-01

    In vitro explant cultures identified Ichthyophonus in 10.9% of 302 Puget Sound rockfish Sebastes emphaeus sampled from five sites in the San Juan Islands archipelago and Puget Sound, Washington, in 2003. None of the infected fish exhibited visible lesions and only a single fish was histologically positive. Significantly more females were infected (12.4%) than males (6.8%), and while infected males were only detected at two of the five sites, infected females were identified at all sites, with no significant differences in infection prevalence. Genomic sequences of Ichthyophonus isolates obtained from Puget Sound rockfish, Pacific herring Clupea pallasii, and Yukon River Chinook salmon Oncorhynchus tshawytscha were identical in both the A and B regions of the small subunit 18S ribosomal DNA but were different from Ichthyophonus sequences previously isolated from four different species of rockfish from the northeastern Pacific Ocean. Ichthyophonus in Puget Sound rockfish may not have been previously detected because the infection is subclinical in this species and earlier investigators did not utilize in vitro techniques for diagnosis of ichthyophoniasis. However, since clinical ichthyophoniasis has recently been identified in several other species of northeast Pacific rockfishes, it is hypothesized that this either is an emerging disease resulting from changing marine conditions or the result of introduction by infected southern species that appear during periodic El Nin??o events. ?? Copyright by the American Fisheries Society 2005.

  17. Population dynamics of the mushroom coral Heliofungia actiniformis in the Spermonde Archipelago, South Sulawesi, Indonesia

    NASA Astrophysics Data System (ADS)

    Knittweis, L.; Jompa, J.; Richter, C.; Wolff, M.

    2009-09-01

    The fungiid Heliofungia actiniformis is one of the most popular coral species in the Indonesian aquarium trade, yet information on the biology of this species is limited. H. actiniformis growth rates, population size-frequency distributions and the seasonality of recruitment rates were measured at three replicate sites in the Spermonde Archipelago, South Sulawesi. Growth and population models were applied to estimate coral ages, mortality rates and the size of maximum yield. Growth decreased linearly with polyp size. High numbers of attached polyps budded from clusters of stalks attached to the reef, with each cluster originating from the settlement of a sexually produced larva. Neither the settlement of sexual recruits, nor their asexual budding, showed seasonality. The overall population structure reflected the high mortality rates of young, attached polyps ( Z = 0.5-0.6 yr-1), and the much lower mortalities of free-living individuals ( Z = 0.05-0.08 yr-1). There were no statistically significant differences in overall mortality rates and the age-frequency distributions of polyps aged 0-15 years between the sites. Differences in the abundance of large H. actiniformis polyps at the three replicate sites were correlated with percent cover of coral rubble. The application of the Beverton and Holt model revealed the highest biomass per H. actiniformis recruit was 12 cm, corresponding to a polyp age of 20 years.

  18. Coral recruitment and potential recovery of eutrophied and blast fishing impacted reefs in Spermonde Archipelago, Indonesia.

    PubMed

    Sawall, Yvonne; Jompa, Jamaluddin; Litaay, Magdalena; Maddusila, Andi; Richter, Claudio

    2013-09-15

    Coral recruitment was assessed in highly diverse and economically important Spermonde Archipelago, a reef system subjected to land-based sources of siltation/pollution and destructive fishing, over a period of 2 years. Recruitment on settlement tiles reached up to 705 spat m(-2) yr(-1) and was strongest in the dry season (July-October), except off-shore, where larvae settled earlier. Pocilloporidae dominated near-shore, while a more diverse community of Acroporidae, Poritidae and others settled in the less polluted mid-shelf and off-shore reefs. Non-coral fouling community appeared to hardly influence initial coral settlement on the tiles, although, this does not necessarily infer low coral post-settlement mortality, which may be enhanced at the near- and off-shore reefs as indicated by increased abundances of potential space competitors on natural substrate. Blast fishing showed no local reduction in coral recruitment and live hard coral cover increased in oligotrophic reefs, indicating potential for coral recovery, if managed effectively.

  19. Subterranean archipelago in the Australian arid zone: mitochondrial DNA phylogeography of amphipods from central Western Australia.

    PubMed

    Cooper, Steven J B; Bradbury, John H; Saint, Kathleen M; Leys, Remko; Austin, Andrew D; Humphreys, William F

    2007-04-01

    In 1998, a unique subterranean ecosystem was discovered in numerous isolated calcrete (carbonate) aquifers in the arid Yilgarn region of Western Australia. Previous morphological and genetic analyses of a subterranean water beetle fauna suggest that calcrete aquifers are equivalent to closed island habitats that have been isolated for millions of years. We tested this hypothesis further by phylogeographic analyses of subterranean amphipods (Crangonyctoidea: Paramelitidae and Hyalidae) using mitochondrial DNA sequence data derived from the cytochrome oxidase I gene. Phylogenetic analyses and population genetic analyses (samova) provided strong evidence for the existence of at least 16 crangonyctoid and six hyalid divergent mitochondrial lineages, each restricted in their distribution to a single calcrete aquifer, in support of the 'subterranean island (archipelago) hypothesis' and extending its scope to include entirely water respiring invertebrates. Sequence divergence estimates between proximate calcrete populations suggest that calcretes have been isolated at least since the Pliocene, coinciding with a major aridity phase that led to the intermittent drying of surface water. The distribution of calcretes along palaeodrainage channels and on either side of drainage divides, have had less influence on the overall phylogeographic structure of populations, with evidence that ancestral crangonyctoid and hyalid species moved between catchments multiple times prior to their isolation within calcretes. At least two potential modes of evolution may account for the diversity of subterranean amphipod populations: dispersal/vicariance of stygobitic species or colonization of calcretes by surface species and independent evolution of stygobitic characteristics.

  20. Whistle variability in South Atlantic spinner dolphins from the Fernando de Noronha archipelago off Brazil.

    PubMed

    Camargo, Fernanda S; Rollo, Mario M; Giampaoli, Viviana; Bellini, Claudio

    2006-12-01

    A series of quali- and quantitative analyses were conducted to evaluate the variability of spinner dolphin whistles from the Fernando de Noronha Archipelago off Brazil. Nine variables were extracted from each whistle contour, and the whistle contours shapes were classified into the seven categories described in Driscoll (1995). The analysis showed mean beginning and ending frequencies values of 10.78 and 12.74 kHz, respectively. On average, whistle duration was relatively short, with mean values around 0.495 s (N=702). Comparative analyses were also conducted to investigate the relationship between the obtained results and those presented in previous studies. When comparing averages, the results of the study of Oswald et al.(2003) in the Tropical Eastern Pacific (TEP) presented less significant differences in relation to this study; only whistle duration differed significantly between both works. The results of multivariate classification tests also pointed TEP population as the closest related to the population studied here. The similarities between such disjunct populations might be attributed to a more recent isolation event (the closing of the Panama Isthmus) than the divergence that has driven North and South Atlantic populations apart.

  1. Summertime community structure of intertidal macrobenthos in Changdao Archipelago, Shandong Province, China

    NASA Astrophysics Data System (ADS)

    Wang, Xiaochen; Li, Xinzheng; Li, Baoquan; Wang, Hongfa

    2009-09-01

    The community structure of intertidal macrobenthos in Changdao Archipelago (north of Shandong Peninsula, between Bohai Bay and the northern Yellow Sea) was examined based on samples collected from 14 stations in five transects in June 2007. Three stations corresponding to high, medium and low tidal areas were set up for each transect. A total of 68 macrobenthic species were found in the research region, most of which belonged to Mollusca and Crustacea. The average abundance and biomass of the macrobenthos was 1 383 ind./m2 and 372.41 g/m2, respectively. The use of an arbitrary similarity level of 20% resulted in identification of five groups among the 14 stations in the research region. There were remarkable differences in the biomass, abundance and Shannon-Wiener diversity index of the different sediments. Specifically, the order of biomass was rocky shores > gravel > mud-sand > coarse sand > stiff mud, while the order of abundance was rocky shores > coarse sand > mud-sand > gravel > stiff mud, and that of the diversity index was mud-sand > gravel > stiff mud > rocky shores > coarse sand. The above results revealed that the sediment type was the most important factor affecting the structure of the macrobenthic community of the intertidal zone.

  2. Monitoring of heavy metal partitioning in reef corals of Lakshadweep Archipelago, Indian Ocean.

    PubMed

    Anu, G; Kumar, N C; Jayalakshmi, K J; Nair, S M

    2007-05-01

    This paper focuses on the partitioning of trace metals in five selected coral species from Lakshadweep Archipelago, which remains as one of the least studied areas in the Indian Ocean. Based on the morphological features, selected coral species are classified as massive (Porites andrewsi), ramose or branching (Lobophyllia corymbosa, Acropora formosa and Psammocora contigua) and foliaceous (Montipora digitata). Relating trace metal concentrations with morphological features in skeleton, highest concentrations of all the trace metals (except Zn) were reported for the ramose type corals. In tissue, all the metals (essential as well as non essential) showed highest concentrations within the branching type corals. Irrespective of their growth characteristics/pattern, all species except P. contigua displayed higher concentrations of Pb, Ni, Mn and Cd within their skeleton compared to tissue which may exemplify a regulatory mechanism to avoid the build up of the concentrations of these metals in their bio-part, strikingly toxic metals like Cd and Pb. The concentrations of trace metals in the skeleton and tissues of these coral species were subjected to 3 way ANOVA based on non standardized original data and the results showed significant differences between metals and between species leading to high skeleton/ tissue - species interaction as well as skeleton/tissue - metal interaction. The significant values of student's t calculated are depicted in the form of Trellis diagrams.

  3. Historical change of mercury pollution in remote Yongle archipelago, South China Sea.

    PubMed

    Liu, Xiaodong; Xu, Liqiang; Chen, Qianqian; Sun, Liguang; Wang, Yuhong; Yan, Hong; Liu, Yi; Luo, Yuhan; Huang, Jing

    2012-04-01

    We collected three ornithogenic coral sand sedimentary profiles from Jinyin Island, Jinqing Island and Guangjin Island of Yongle archipelago, South China Sea and reconstructed the deposition flux of anthropogenic Hg over the past 700 years in the study area. On the whole, the anthropogenic Hg flux is relatively low; it remained at a low level before the Industrial Revolution with a small peak at about 1450-1550 AD, which may record the enhanced metallurgy activity in Ming Dynasty of China. During the 20th century, the deposition flux of anthropogenic Hg increased rapidly, but two troughs occurred during the periods around 1940s and 1970s, corresponding to the economic depression caused by World War II, Civil War in China (1945-1949), and the Culture Revolution (1966-1976) in China. Since the 1970s the deposition flux of anthropogenic Hg has been persistently increasing, apparently the result of fast economic development in East and Southeast Asia countries around South China Sea.

  4. Testing the island effect on phenotypic diversification: insights from the Hemidactylus geckos of the Socotra Archipelago

    PubMed Central

    Garcia-Porta, Joan; Šmíd, Jiří; Sol, Daniel; Fasola, Mauro; Carranza, Salvador

    2016-01-01

    Island colonization is often assumed to trigger extreme levels of phenotypic diversification. Yet, empirical evidence suggests that it does not always so. In this study we test this hypothesis using a completely sampled mainland-island system, the arid clade of Hemidactylus, a group of geckos mainly distributed across Africa, Arabia and the Socotra Archipelago. To such purpose, we generated a new molecular phylogeny of the group on which we mapped body size and head proportions. We then explored whether island and continental taxa shared the same morphospace and differed in their disparities and tempos of evolution. Insular species produced the most extreme sizes of the radiation, involving accelerated rates of evolution and higher disparities compared with most (but not all) of the continental groups. In contrast, head proportions exhibited constant evolutionary rates across the radiation and similar disparities in islands compared with the continent. These results, although generally consistent with the notion that islands promote high morphological disparity, reveal at the same time a complex scenario in which different traits may experience different evolutionary patterns in the same mainland-island system and continental groups do not always present low levels of morphological diversification compared to insular groups. PMID:27071837

  5. Testing the island effect on phenotypic diversification: insights from the Hemidactylus geckos of the Socotra Archipelago.

    PubMed

    Garcia-Porta, Joan; Šmíd, Jiří; Sol, Daniel; Fasola, Mauro; Carranza, Salvador

    2016-04-13

    Island colonization is often assumed to trigger extreme levels of phenotypic diversification. Yet, empirical evidence suggests that it does not always so. In this study we test this hypothesis using a completely sampled mainland-island system, the arid clade of Hemidactylus, a group of geckos mainly distributed across Africa, Arabia and the Socotra Archipelago. To such purpose, we generated a new molecular phylogeny of the group on which we mapped body size and head proportions. We then explored whether island and continental taxa shared the same morphospace and differed in their disparities and tempos of evolution. Insular species produced the most extreme sizes of the radiation, involving accelerated rates of evolution and higher disparities compared with most (but not all) of the continental groups. In contrast, head proportions exhibited constant evolutionary rates across the radiation and similar disparities in islands compared with the continent. These results, although generally consistent with the notion that islands promote high morphological disparity, reveal at the same time a complex scenario in which different traits may experience different evolutionary patterns in the same mainland-island system and continental groups do not always present low levels of morphological diversification compared to insular groups.

  6. Exposure to viral and bacterial pathogens among Soay sheep (Ovis aries) of the St Kilda archipelago.

    PubMed

    Graham, A L; Nussey, D H; Lloyd-Smith, J O; Longbottom, D; Maley, M; Pemberton, J M; Pilkington, J G; Prager, K C; Smith, L; Watt, K A; Wilson, K; McNEILLY, T N; Brülisauer, F

    2016-07-01

    We assessed evidence of exposure to viruses and bacteria in an unmanaged and long-isolated population of Soay sheep (Ovis aries) inhabiting Hirta, in the St Kilda archipelago, 65 km west of Benbecula in the Outer Hebrides of Scotland. The sheep harbour many metazoan and protozoan parasites but their exposure to viral and bacterial pathogens is unknown. We tested for herpes viral DNA in leucocytes and found that 21 of 42 tested sheep were infected with ovine herpesvirus 2 (OHV-2). We also tested 750 plasma samples collected between 1997 and 2010 for evidence of exposure to seven other viral and bacterial agents common in domestic Scottish sheep. We found evidence of exposure to Leptospira spp., with overall seroprevalence of 6·5%. However, serological evidence indicated that the population had not been exposed to border disease, parainfluenza, maedi-visna, or orf viruses, nor to Chlamydia abortus. Some sheep tested positive for antibodies against Mycobacterium avium subsp. paratuberculosis (MAP) but, in the absence of retrospective faecal samples, the presence of this infection could not be confirmed. The roles of importation, the pathogen-host interaction, nematode co-infection and local transmission warrant future investigation, to elucidate the transmission ecology and fitness effects of the few viral and bacterial pathogens on Hirta.

  7. Integrating terrestrial and marine archives of Late Wisconsinan ice stream dynamics in the Canadian Arctic Archipelago

    NASA Astrophysics Data System (ADS)

    Lakeman, Thomas; Blasco, Steve; MacLean, Brian; Bennett, Robbie; England, John; Hughes Clarke, John; Covill, Bob; Patton, Eric

    2014-05-01

    During Late Wisconsinan glaciation the northern Laurentide and Innuitian ice sheets converged over the Canadian Arctic Archipelago. This ice sheet complex included several major ice streams, which constituted important dynamical components. Discharging into the Beaufort Sea and Baffin Bay, these ice streams were a primary control on ice sheet mass balance and ice age sedimentation on adjacent continental margins, including the Arctic Ocean basin. This study presents a new compilation of multibeam echosounder data, sub-bottom profiler data, radiocarbon ages, and marine sediment cores acquired primarily during regional surveys with the CCGS Amundsen. These data characterize the nature and thickness of seafloor sediments in Parry Channel (and many of its connecting channels) and Amundsen Gulf. When combined with the results of terrestrial geomorphological mapping of the adjacent islands, this dataset constrains the maximum extent, chronology, and behaviour of former ice streams in M'Clure Strait, Viscount Melville Sound, Lancaster Sound, and Amundsen Gulf. Importantly, these data highlight complex patterns of past ice stream flow during regional deglaciation. These results contribute to a better understanding of the causal mechanisms that occasioned retreat of the terrestrial and marine sectors of the Laurentide and Innuitian ice sheets. As well, this study helps to quantify past iceberg fluxes to the Arctic Ocean, which has implications for assessing past climate, and the origin of ice-rafted sediment and deep iceberg scours in the Arctic Ocean basin.

  8. Spatial distribution of oxygen-18 and deuterium in stream waters across the Japanese archipelago

    NASA Astrophysics Data System (ADS)

    Katsuyama, M.; Yoshioka, T.; Konohira, E.

    2014-09-01

    The spatial distribution of oxygen and hydrogen isotopic composition (δ18O and δ2H) of stream waters across Japan was clarified with a data set compiling sample data obtained from 1278 forest catchments during the summer of 2003. Both δ18O and δ2H values showed positive correlations with the mean annual air temperature and annual evapotranspiration, and negative correlations with latitude and elevation. Deuterium excess (d excess) values in stream waters were higher on the Sea of Japan side, and lower on the Pacific Ocean side, of the Japanese archipelago. The d excess in precipitation was generally higher in winter and lower in summer in Japan. The Sea of Japan side experiences a great deal of snowfall, and seasonal changes in monthly precipitation are rather small. In contrast, the Pacific Ocean side experiences a large amount of rainfall during summer with low levels of precipitation during the winter. Therefore, the lower d excess in stream waters on the Pacific Ocean side reflects summer precipitation, and the higher values on the Sea of Japan side are affected by delayed recharge from snowmelt. The isoscapes of stream water connote not only spatially integrated but also temporally integrated isotope signals of precipitation, and provide a framework for addressing applied hydrological, ecological, or meteorological research questions at regional scales, such as the effects of climate change.

  9. Spatial distribution of oxygen-18 and deuterium in stream waters across the Japanese archipelago

    NASA Astrophysics Data System (ADS)

    Katsuyama, M.; Yoshioka, T.; Konohira, E.

    2015-03-01

    The spatial distribution of oxygen and hydrogen isotopic composition (δ18O and δ2H) of stream waters across Japan was clarified with a data set by compiling sample data obtained from 1278 forest catchments during the summer of 2003. Both δ18O and δ2H values showed positive correlations with the mean annual air temperature and annual evapotranspiration, and negative correlations with latitude and elevation. Deuterium excess (d-excess) values in stream waters were higher on the Sea of Japan side, and lower on the Pacific Ocean side, of the Japanese archipelago. The d-excess in precipitation was generally higher in winter and lower in summer in Japan. The Sea of Japan side experiences a great deal of snowfall, and seasonal changes in monthly precipitation are rather small. In contrast, the Pacific Ocean side experiences a large amount of rainfall during summer with low levels of precipitation during the winter. Therefore, the lower d-excess in stream waters on the Pacific Ocean side reflects summer precipitation, and the higher values on the Sea of Japan side are affected by delayed recharge from snowmelt. The isoscapes of stream water connote not only spatially integrated but also temporally integrated isotope signals of precipitation and provide a framework for addressing applied hydrological, ecological, or meteorological research questions at regional scales, such as the effects of climate change.

  10. Morphological and genetic diversity of Briareum (Anthozoa: Octocorallia) from the Ryukyu Archipelago, Japan.

    PubMed

    Miyazaki, Yu; Reimer, James Davis

    2014-10-01

    The primary problem hindering the study of octocorals is the disordered situation regarding their taxonomy, chiefly caused by insufficient knowledge of valid morphological taxonomic characters. Briareum is an octocoral genus found in the Atlantic and Pacific in shallow tropical and subtropical waters, and occurs in both encrusting and branching colony forms. Their simple morphology and morphological plasticity have hindered taxonomic understanding of this genus. In this study three morphologically distinct types (= type-1, -2, and -3) of Briareum from the Ryukyu Archipelago and their genetic diversity were examined. Colony, anthostele morphology, and sclerite length were examined for each type. Four molecular markers (mitochondrial cytochrome c oxidase subunit 1, mitochondrial mismatch repair gene, nuclear 18S ribosomal DNA, internal transcribed spacer 2 (ITS2)) were used to evaluate molecular phylogenetic status of these variations. Although one morphological type ("deep" small colonies, = type-3) showed small differences in nuclear ITS2 sequences compared to the other two types, the remaining types had identical sequences for all molecular markers examined. The results suggest extremely low genetic diversity despite highly variable morphology of Briareum species in Okinawa. Nevertheless, considering the distribution patterns and discontinuous morphology of type-3 compared to the other two morphotypes, genetic isolation of type-3 is plausible. In Briareum, small variances in nuclear ITS2 sequences of type-3 may have much more importance than in molecular phylogenies of other octocorals. Further phylogenetic investigations and comparison with Briareum specimens from other regions are necessary to conclusively taxonomically identify the three types.

  11. Blood meal identification and feeding habits of uranotaenia species collected in the ryukyu archipelago.

    PubMed

    Toma, Takako; Miyagi, Ichiro; Tamashiro, Mikako

    2014-09-01

    To know the blood meal in the stomach of Uranotaenia species, blood-fed mosquitoes were collected by 4 methods at different sites in the mountain forest of 3 islands, Amamioshima, Okinawajima, and Iriomotejima in the Ryukyu Archipelago, Japan from 2005 to 2012. One hundred twenty-four blood-fed Uranotaenia mosquitoes of 7 species (Ur. jacksoni, nivipleura, ohamai, yaeyamana, annandalei, lateralis, and macfarlanei) were collected. The collection rates are 0.26, 0.6, 0.31, and 0.66 by black light trap, black light blue with dry ice trap, frog call trap, and sweeping net, respectively. The blood meals of 107 females (86.3%) were successfully identified by a polymerase chain reaction-based method. All Uranotaenia species fed on cold-blooded animals, especially amphibians (99.1%), and notably on frogs. They would feed readily on available frogs in a given region having no close connection with the breeding (calling) season of each frog. They also fed on reptiles (0.9%), but not on warm-blooded animals.

  12. Two new species of diplosoma (Ascidiacea: Didemnidae) bearing prokaryotic algae prochloron from Okinawajima (Ryukyu Archipelago, Japan).

    PubMed

    Oka, Atsushi T; Suetsugu, Mayu; Hirose, Euichi

    2005-03-01

    Two new species of didemnid ascidians, Diplosoma ooru sp. nov. and Diplosoma simileguwa sp. nov., are described from coral reefs on Okinawajima (Ryukyu Archipelago, Japan). These two species form green colonies, having a symbiotic association with a prokaryotic alga Prochloron sp. The former species was found at the reef edges in the subtidal zone and the latter was found in a shallow reef lagoon. In these species, the colonies are thinner and the zooids are smaller than those of any other Prochloron-bearing Diplosoma species so far described. Moreover, each of the present new species has a unique combination of stigmatic numbers: 5 stigmata in the first and third rows, 6 in the second row, and 4 in the fourth in D. ooru; 4 stigmata in the first and third rows, 5 in the second row, and 3 in the fourth in D. simileguwa. In both of the new species, the retractor muscle emerges from the underside of the thorax. Larval morphology of D. ooru is also described.

  13. Genome-wide SNP analysis explains coral diversity and recovery in the Ryukyu Archipelago.

    PubMed

    Shinzato, Chuya; Mungpakdee, Sutada; Arakaki, Nana; Satoh, Noriyuki

    2015-12-10

    Following a global coral bleaching event in 1998, Acropora corals surrounding most of Okinawa island (OI) were devastated, although they are now gradually recovering. In contrast, the Kerama Islands (KIs) only 30 km west of OI, have continuously hosted a great variety of healthy corals. Taking advantage of the decoded Acropora digitifera genome and using genome-wide SNP analyses, we clarified Acropora population structure in the southern Ryukyu Archipelago (sRA). Despite small genetic distances, we identified distinct clusters corresponding to specific island groups, suggesting infrequent long-distance dispersal within the sRA. Although the KIs were believed to supply coral larvae to OI, admixture analyses showed that such dispersal is much more limited than previously realized, indicating independent recovery of OI coral populations and the necessity of local conservation efforts for each region. We detected strong historical migration from the Yaeyama Islands (YIs) to OI, and suggest that the YIs are the original source of OI corals. In addition, migration edges to the KIs suggest that they are a historical sink population in the sRA, resulting in high diversity. This population genomics study provides the highest resolution data to date regarding coral population structure and history.

  14. Kinematics of deformation across the Philippine Archipelago as observed from GPS campaign data

    NASA Astrophysics Data System (ADS)

    Bacolcol, T.; Solidum, R., Jr.; Yu, S.; Phivolcs Gps Team

    2010-12-01

    More than 150 Global Positioning System (GPS) points across the Philippine archipelago have been installed by the Philippine Institute of Volcanology and Seismology (PHIVOLCS) and its collaborative partners. Results from the repeated GPS measurements conducted since 1996 up to the present on these points showed the following: (1) Based on uniform motion and velocity directions gathered from the GPS data, the Philippine Mobile Belt can generally be subdivided into three blocks: Central to Northern Luzon; Southern Luzon to Southern Visayas; Mindanao; (2) There is a significant internal deformation in the Philippine Mobile Belt as seen from variable velocities and azimuth directions relative to Eurasian plate. (3) Relative velocities across the Philippine Fault vary from 20 mm/yr to 29 mm/yr (vector azimuths from 322 deg to 4 deg) in Northern Luzon; 31.2 mm/yr to 53.3 mm/yr (300 deg to 310 deg) in Southern Luzon; 20.5 mm/yr to 25.1 mm/yr (305 deg to 347 deg) in Visayas and 14 mm/yr to 33 mm/yr (338 deg to 40 deg) in Mindanao. (4) There is an active extensional deformation (18 mm/yr) in Macolod Corridor while compressional deformation (24 mm/yr) exists between Southern Visayas and Mindanao. This reverse analogue of deformation is probably the result of the collision between Palawan and the Philippine Mobile Belt.

  15. Immediate replacement of fishing with dairying by the earliest farmers of the northeast Atlantic archipelagos

    PubMed Central

    Cramp, Lucy J. E.; Jones, Jennifer; Sheridan, Alison; Smyth, Jessica; Whelton, Helen; Mulville, Jacqui; Sharples, Niall; Evershed, Richard P.

    2014-01-01

    The appearance of farming, from its inception in the Near East around 12 000 years ago, finally reached the northwestern extremes of Europe by the fourth millennium BC or shortly thereafter. Various models have been invoked to explain the Neolithization of northern Europe; however, resolving these different scenarios has proved problematic due to poor faunal preservation and the lack of specificity achievable for commonly applied proxies. Here, we present new multi-proxy evidence, which qualitatively and quantitatively maps subsistence change in the northeast Atlantic archipelagos from the Late Mesolithic into the Neolithic and beyond. A model involving significant retention of hunter–gatherer–fisher influences was tested against one of the dominant adoptions of farming using a novel suite of lipid biomarkers, including dihydroxy fatty acids, ω-(o-alkylphenyl)alkanoic acids and stable carbon isotope signatures of individual fatty acids preserved in cooking vessels. These new findings, together with archaeozoological and human skeletal collagen bulk stable carbon isotope proxies, unequivocally confirm rejection of marine resources by early farmers coinciding with the adoption of intensive dairy farming. This pattern of Neolithization contrasts markedly to that occurring contemporaneously in the Baltic, suggesting that geographically distinct ecological and cultural influences dictated the evolution of subsistence practices at this critical phase of European prehistory. PMID:24523264

  16. Epidemiological survey of zoonotic helminths in feral cats in Gran Canaria island (Macaronesian archipelago-Spain).

    PubMed

    Rodríguez-Ponce, Eligia; González, Jorge F; Conde de Felipe, Magnolia; Hernández, Julia N; Raduan Jaber, J

    2016-09-01

    The presence of zoonotic parasites in feral cats have been widely considered all over the world. In Gran Canaria (Macaronesian archipelago, Canary Islands, Spain) the number of feral cats has grown out of control in urban and rural areas. 48 of Felis catus captured in different Gran Canaria areas were studied. Animals were necropsied and several organs were systematically examined in order to collect and identify macroscopic parasites. In addition, coprological tests were done in 28 cats. There were no statistically significant differences in the prevalence rate among sex, age or capture area, showing an overall prevalence of helminths of 77.1%. The most common tapeworms were Dipylidium caninum (64.6%) and Taenia taeniaeformis (31.3%), followed by the nematodes Toxocara cati (20.8%), Ancylostoma tubaeforme (18.8%), Aelurostrongylusabstrusus (10.4%) and Trichuris vulpis (2.08%). We also find several eggs of Alaria alata in the small intestine of one cat (2.08%), being the first description of this trematode in cats in the Canary Islands. Aproximatelly, 40% of the studied cats harboured more than one parasite. High rates of zoonotic species found in these animals suggest the need of controling parasitic infections and preventive measures against them.

  17. [Changes in fish communities of coral reefs at Sabana-Camagüey Archipelago, Cuba].

    PubMed

    Claro, Rodolfo; Cantelar, Karel; Amargós, Fabián Pina; García-Arteaga, Juan P

    2007-06-01

    A comparison of fish community structure in the Sabana-Camagüey Archipelago (1988-1989 and 2000) using visual census surveys (eight belt transects 2x50 m in each site) suggests a notable decrease on species richness, and a two thirds reduction in fish density and biomass on coral reefs. This decrease in fish populations may be related to the alarming decrease of scleractinian coral cover, and an enormous proliferation of algae, which currently covers 70-80% of the hard substrate, impeding the recovery of corals and other benthic organisms. High coral mortalities occurred between the study periods, which correlate with the high temperatures caused by the ENSO events of 1995, 1997 and 1998. These events caused massive bleaching of corals and subsequent algae overgrowth. Evidence of nutrient enrichment from the inner lagoons and overfishing are also present. Collectively, these effects have provoked a marked degradation of reef habitats. These changes appear to have affected the availability of refuges and food for fishes, and may be constraining individual growth potential and population size.

  18. Natural trace element enrichment in fishes from a volcanic and tectonically active region (Azores archipelago)

    NASA Astrophysics Data System (ADS)

    Raimundo, Joana; Vale, Carlos; Caetano, Miguel; Giacomello, Eva; Anes, Bárbara; Menezes, Gui M.

    2013-12-01

    Seamounts, in general, are thought to support high biodiversity and special biological communities. They have been targeted by commercial fishing for demersal and pelagic fish species due to the occurrence of large aggregations in mid- and deep-water. Specimens of Phycis phycis, Helicolenus dactylopterus, Pontinus kuhlii, Beryx splendens, Beryx decadactylus, Etmopterus pusillus, Mora moro, Pagellus bogaraveo, Deania profundorum, Scomber colias and Trachurus picturatus were collected at the Condor seamount and on the slopes of Faial and Pico islands of Azores archipelago. Concentrations of V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Cd and Pb were determined in muscle and liver of each individual. Values of the 11 trace elements in the two tissues of the benthopelagic and benthic specimens, from the two surveyed areas, presented a significant inter-specific variation. In general, levels were lower in muscle than in liver, and negative relations between weight and Co, Mn, Zn, As, Cd and Pb concentrations in muscle and liver of three species were found. Pagellus bogaraveo, S. colias and T. picturatus presented enhanced elemental concentrations in liver, particularly of Cd. The extremely high storage of this potentially toxic element suggests a response to high uptake of Cd and the existence of an additional natural source of Cd to the environment.

  19. Gender and population history: sex bias revealed by studying genetic admixture of Ngazidja population (Comoro Archipelago).

    PubMed

    Gourjon, Géraud; Boëtsch, Gilles; Degioanni, Anna

    2011-04-01

    The peopling of Comoro Archipelago is defined by successive waves of migration from three main areas: the East African Coast (Bantu-speaking populations), the Persia and Arabian Peninsula, and Southeast Asia (especially Indonesia). It follows an apparent classic trihybrid admixture model. To better understand the Comorian population admixture dynamics, we analyzed the contributions of these three historical parental components to its genetic pool. To enhance accuracy and reliability, we used both classical and molecular markers. Samples consist of published data: blood group frequencies, 14 KIR genes, 19 mitochondrial DNA SNPs (to highlight female migrations), 14 Y chromosome SNPs (male migrations). We revealed distinct admixture patterns for autosomal and uniparental markers. KIR gene frequencies had never been used to estimate admixture rates, this being a first assessment of their informative power in admixture studies. To avoid major methodological and statistical bias, we determined admixture coefficients through nine well-tried estimators and their associated software programs (ADMIX95, ADMIX, admix 2.0, LEA, LEADMIX, and Mistura). Results from mtDNA and Y chromosome markers point to an important sex-bias in the admixture event. The original Bantu gene pool received a predominant male-mediated contribution from the Arabian Peninsula and Persia, and a female-mediated contribution from Southeast Asia. Admixture rates estimated from autosomal KIR gene markers point also to an unexpected elevated Austronesian contribution.

  20. Tropical storm off Myanmar coast sweeps reefs in Ritchie's Archipelago, Andaman.

    PubMed

    Krishnan, P; Grinson-George; Vikas, N; Titus-Immanuel, Titus; Goutham-Bharathi, M P; Anand, A; Kumar, K Vinod; Kumar, S Senthil

    2013-06-01

    The reefs in some islands of Andaman and Nicobar suffered severe damage following a tropical storm in the Bay of Bengal off Myanmar coast during 13-17 March 2011. Surveys were conducted at eight sites in Andaman, of which five were located in the Ritchie's Archipelago where maximum wind speeds of 11 m s(-1) was observed; and three around Port Blair which lay on the leeward side of the storm and had not experienced wind speeds of more than 9 m s(-1). Corals in the shallow inshore reefs were broken and dislodged by the thrust of the waves. Significant damage in the deeper regions and offshore reefs were caused by the settlement of debris and sand brought down from the shallower regions. The fragile branching corals (Acropora sp.) were reduced to rubbles and the larger boulder corals (Porites sp.) were toppled over or scarred by falling debris. The reefs on the windward side and directly in the path of the storm winds were the worst affected. The investigation exposes the vulnerability of the reefs in Andaman to the oceanographic features which generally remain unnoticed unless the damage is caused to the coastal habitats.

  1. Comparative phylogeography of two closely related Viola species occurring in contrasting habitats in the Japanese archipelago.

    PubMed

    Toyama, Hironori; Yahara, Tetsukazu

    2009-07-01

    Similar distribution ranges shared by closely related plant species may have been shaped through different migration histories if those species have differing habitat preference. To test this hypothesis, phylogeographical patterns and population genetic structures were compared between two sister Viola species: Viola eizanensis preferring woodland and V. chaerophylloides var. sieboldiana preferring grassland, both being native to the Japanese Archipelago. Amplified fragment length polymorphism (AFLP) was used for phylogenetic reconstruction, together with Bayesian ancestry analysis, AMOVA, analysis of genetic diversity statistics, and analysis of the relative contribution of each population to total diversity. The results indicated that V. eizanensis had two distinct lineages occurring in the western and eastern part of Japan, but such lineages are not distinct in V. chaerophylloides var. sieboldiana. Both species exhibited the low genetic diversity and high between-population differentiation typical of selfing plants. In V. chaerophylloides var. sieboldiana, one particular population made a significantly higher contribution to the total heterozygosity (H (T)), whereas in V. eizanensis, no population was identified as making a particularly higher contribution to H (T). These findings suggest that V. eizanensis had been isolated in two large glacial refugia, whereas populations of V. chaerophylloides var. sieboldiana were restricted to a single small refuge. Different light requirements between these two closely related species probably caused these differing responses to climatic change during the last ice age.

  2. Genome-wide SNP analysis explains coral diversity and recovery in the Ryukyu Archipelago

    PubMed Central

    Shinzato, Chuya; Mungpakdee, Sutada; Arakaki, Nana; Satoh, Noriyuki

    2015-01-01

    Following a global coral bleaching event in 1998, Acropora corals surrounding most of Okinawa island (OI) were devastated, although they are now gradually recovering. In contrast, the Kerama Islands (KIs) only 30 km west of OI, have continuously hosted a great variety of healthy corals. Taking advantage of the decoded Acropora digitifera genome and using genome-wide SNP analyses, we clarified Acropora population structure in the southern Ryukyu Archipelago (sRA). Despite small genetic distances, we identified distinct clusters corresponding to specific island groups, suggesting infrequent long-distance dispersal within the sRA. Although the KIs were believed to supply coral larvae to OI, admixture analyses showed that such dispersal is much more limited than previously realized, indicating independent recovery of OI coral populations and the necessity of local conservation efforts for each region. We detected strong historical migration from the Yaeyama Islands (YIs) to OI, and suggest that the YIs are the original source of OI corals. In addition, migration edges to the KIs suggest that they are a historical sink population in the sRA, resulting in high diversity. This population genomics study provides the highest resolution data to date regarding coral population structure and history. PMID:26656261

  3. Antioxidant Capacity, Cytotoxicity and Antimycobacterial Activity of Madeira Archipelago Endemic Helichrysum Dietary and Medicinal Plants.

    PubMed

    Gouveia-Figueira, Sandra C; Gouveia, Carla A; Carvalho, Maria J; Rodrigues, Ana I; Nording, Malin L; Castilho, Paula C

    2014-10-31

    The potential bioactivity of dietary and medicinal endemic Helichrysum plants from Madeira Archipelago was explored, for the first time, in order to supply new information for the general consumer. In vitro antioxidant properties were investigated using DPPH, ABTS(•+), FRAP and β-Carotene assays, and the total phenolic content (TPC) and total flavonoid content (TFC) were also determined. Although the results generally showed a large variation among the three analyzed plants, the methanolic extracts showed the highest antioxidant capacity. Exception is made for H. devium n-hexane extract that showed good radical scavenger capacity associated to compounds with good reducing properties. In the Artemia salina toxicity assay and antimycobaterial activity, H. devium was the most potent plant with the lowest LD50 at 216.7 ± 10.4 and MIC ≤ 50 μg·mL(-1). Chemometric evaluation (Principal Component Analysis-PCA) showed close interdependence between the ABTS, TPC and TFC methods and allowed to group H. devium samples.

  4. [Diversity patterns in intertidal communities of three southern islands of Changshan archipelago].

    PubMed

    Zhuang, Shuhong; Chen, Lixue; Wang, Zunqing

    2003-05-01

    The diversity pattern of intertidal communities in 3 southern islands of Changshan archipelago were studied. The results showed that the community appearance and structure in rocky intertidal zones of 3 islands were regimented by dominant species Chthamalus challengeri, Ostrea spp., macro-algae and Littorina brevicula, while in gravel intertidal zones of Southern Changshan and Daheishan regimented by Chthamalus challengeri, Littorina brevicula, Ostrea spp., and in Northern Changshan, by Chthamalus challengeri, macro-algae and Gaetice depressus. There existed no obvious difference in community structures of rocky intertidal zones among 3 islands, which was demonstrated by the similarity in first 5 dominant species and their dominance ranks in the community. However, a significant difference was achieved in gravel intertidal communities, in which, the dominant species in the community at Northern Changshan differed greatly from that of others. The community diversity in R, J, D(B), D(IV), H(B), and H(IV), in rocky intertidal communities among 3 islands showed a great coincidence, Northern Changshan > Southern Changshan > Daheishan, however, little coincident results were found among gravel intertidal communities. It was found that there existed a higher community diversity in gravel intertidal communities at Daheishan and Southern Changshan than at Northern Changshan where existed the highest species evenness. The community diversity was generally higher in gravel intertidal communities than in rocky intertidal ones. The variation in community compositions, structures and diversities were resulted mainly from topographical heterogeneities, substratum heterogeneities, hydrodynamics, water eutrophication and human disturbance in intertidal zones.

  5. Identifying multiple coral reef regimes and their drivers across the Hawaiian archipelago

    PubMed Central

    Jouffray, Jean-Baptiste; Nyström, Magnus; Norström, Albert V.; Williams, Ivor D.; Wedding, Lisa M.; Kittinger, John N.; Williams, Gareth J.

    2015-01-01

    Loss of coral reef resilience can lead to dramatic changes in benthic structure, often called regime shifts, which significantly alter ecosystem processes and functioning. In the face of global change and increasing direct human impacts, there is an urgent need to anticipate and prevent undesirable regime shifts and, conversely, to reverse shifts in already degraded reef systems. Such challenges require a better understanding of the human and natural drivers that support or undermine different reef regimes. The Hawaiian archipelago extends across a wide gradient of natural and anthropogenic conditions and provides us a unique opportunity to investigate the relationships between multiple reef regimes, their dynamics and potential drivers. We applied a combination of exploratory ordination methods and inferential statistics to one of the most comprehensive coral reef datasets available in order to detect, visualize and define potential multiple ecosystem regimes. This study demonstrates the existence of three distinct reef regimes dominated by hard corals, turf algae or macroalgae. Results from boosted regression trees show nonlinear patterns among predictors that help to explain the occurrence of these regimes, and highlight herbivore biomass as the key driver in addition to effluent, latitude and depth.

  6. Clutch size in the tropical scincid lizard Emoia sanfordi, a species endemic to the Vanuatu Archipelago.

    PubMed

    Hamilton, Alison Madeline; Eckstut, Mallory Elizabeth; Klein, Elaine Renee; Austin, Christopher Cowell

    2008-08-01

    The majority of species in the scincid genus Emoia (Squamata: Scincidae) have a fixed clutch size of two eggs per clutch and produce between two and four clutches per year. One lineage within Emoia, the Emoia samoensis species group, consists of 13 species occurring in Melanesia and the islands of the southwestern Pacific Ocean, and exhibits variation in clutch size, with previously reported clutch sizes of two to five eggs. Little is known about reproduction in several members of this lineage including Emoia sanfordi, a large-bodied lizard endemic to the archipelago of Vanuatu in the South Pacific. We analyzed reproduction and clutch size in E. sanfordi females and discovered that there is a substantial amount of intraspecific variation, with clutch size ranging from two to seven eggs, with a modal clutch size of five eggs. Females were reproductively active throughout the study period of June through October and appear to be laying multiple clutches. The variation in clutch size seen in E. sanfordi is congruent with the variation previously reported within other closely related species.

  7. Imaging rapidly deforming ocean island volcanoes in the western Galápagos archipelago, Ecuador

    NASA Astrophysics Data System (ADS)

    Tepp, Gabrielle; Ebinger, Cynthia J.; Ruiz, Mario; Belachew, Manahloh

    2014-01-01

    Using local body wave arrival-time tomography methods to determine 3-D seismic velocity structure, we imaged the plumbing system of Sierra Negra Volcano, Galápagos. This hot spot volcanic chain includes some of the fastest deforming volcanoes in the world, making this an ideal location to study shield volcano plumbing systems. We inverted P and S wave arrivals recorded on a 15-station temporary array between July 2009 and June 2011 using an a priori 1-D velocity model constrained by offshore refraction studies. With local seismicity from nearby volcanoes as well as the ring fault system, the model resolution is good between depths of 3 and 15.5 km. The propagation of S waves throughout this volume argues against any large high-melt accumulations, although a shallow melt sill may exist above 5 km. We image a broad low-velocity region (>25 km laterally) below Sierra Negra at depths ~8-15 km. No large, regional velocity increase is found within the limits of good resolution, suggesting that crust is thicker than 15 km beneath the western Galápagos archipelago. Our results are consistent with crustal accretion of mafic cumulates from a large-volume magma chamber that may span the boundary between preplume and accreted crust. The similarity between our results and those of Hawaii leave open the possibility that the crust has also been thickened by under-plating.

  8. Parallel responses of bees to Pleistocene climate change in three isolated archipelagos of the southwestern Pacific

    PubMed Central

    Groom, Scott V. C.; Stevens, Mark I.; Schwarz, Michael P.

    2014-01-01

    The impacts of glacial cycles on the geographical distribution and size of populations have been explored for numerous terrestrial and marine taxa. However, most studies have focused on high latitudes, with only a few focused on the response of biota to the last glacial maximum (LGM) in equatorial regions. Here, we examine how population sizes of key bee fauna in the southwest Pacific archipelagos of Fiji, Vanuatu and Samoa have fluctuated over the Quaternary. We show that all three island faunas suffered massive population declines, roughly corresponding in time to the LGM, followed by rapid expansion post-LGM. Our data therefore suggest that Pleistocene climate change has had major impacts across a very broad tropical region. While other studies indicate widespread Holarctic effects of the LGM, our data suggest a much wider range of latitudes, extending to the tropics, where these climate change repercussions were important. As key pollinators, the inferred changes in these bee faunas may have been critical in the development of the diverse Pacific island flora. The magnitude of these responses indicates future climate change scenarios may have alarming consequences for Pacific island systems involving pollinator-dependent plant communities and agricultural crops. PMID:24807250

  9. Parallel responses of bees to Pleistocene climate change in three isolated archipelagos of the southwestern Pacific.

    PubMed

    Groom, Scott V C; Stevens, Mark I; Schwarz, Michael P

    2014-06-22

    The impacts of glacial cycles on the geographical distribution and size of populations have been explored for numerous terrestrial and marine taxa. However, most studies have focused on high latitudes, with only a few focused on the response of biota to the last glacial maximum (LGM) in equatorial regions. Here, we examine how population sizes of key bee fauna in the southwest Pacific archipelagos of Fiji, Vanuatu and Samoa have fluctuated over the Quaternary. We show that all three island faunas suffered massive population declines, roughly corresponding in time to the LGM, followed by rapid expansion post-LGM. Our data therefore suggest that Pleistocene climate change has had major impacts across a very broad tropical region. While other studies indicate widespread Holarctic effects of the LGM, our data suggest a much wider range of latitudes, extending to the tropics, where these climate change repercussions were important. As key pollinators, the inferred changes in these bee faunas may have been critical in the development of the diverse Pacific island flora. The magnitude of these responses indicates future climate change scenarios may have alarming consequences for Pacific island systems involving pollinator-dependent plant communities and agricultural crops.

  10. Phylogeographic Analyses of Submesophotic Snappers Etelis coruscans and Etelis “marshi” (Family Lutjanidae) Reveal Concordant Genetic Structure across the Hawaiian Archipelago

    PubMed Central

    Andrews, Kimberly R.; Moriwake, Virginia N.; Wilcox, Christie; Grau, E. Gordon; Kelley, Christopher; Pyle, Richard L.; Bowen, Brian W.

    2014-01-01

    The Hawaiian Archipelago has become a natural laboratory for understanding genetic connectivity in marine organisms as a result of the large number of population genetics studies that have been conducted across this island chain for a wide taxonomic range of organisms. However, population genetic studies have been conducted for only two species occurring in the mesophotic or submesophotic zones (30+m) in this archipelago. To gain a greater understanding of genetic connectivity in these deepwater habitats, we investigated the genetic structure of two submesophotic fish species (occurring ∼200–360 m) in this archipelago. We surveyed 16 locations across the archipelago for submesophotic snappers Etelis coruscans (N = 787) and E. “marshi” (formerly E. carbunculus; N = 770) with 436–490 bp of mtDNA cytochrome b and 10–11 microsatellite loci. Phylogeographic analyses reveal no geographic structuring of mtDNA lineages and recent coalescence times that are typical of shallow reef fauna. Population genetic analyses reveal no overall structure across most of the archipelago, a pattern also typical of dispersive shallow fishes. However some sites in the mid-archipelago (Raita Bank to French Frigate Shoals) had significant population differentiation. This pattern of no structure between ends of the Hawaiian range, and significant structure in the middle, was previously observed in a submesophotic snapper (Pristipomoides filamentosus) and a submesophotic grouper (Hyporthodus quernus). Three of these four species also have elevated genetic diversity in the mid-archipelago. Biophysical larval dispersal models from previous studies indicate that this elevated diversity may result from larval supplement from Johnston Atoll, ∼800 km southwest of Hawaii. In this case the boundaries of stocks for fishery management cannot be defined simply in terms of geography, and fishery management in Hawaii may need to incorporate external larval supply into management plans

  11. Arctic atmospheric circulation patterns responsible for dry and cold air inflows to the Baltic Sea region

    NASA Astrophysics Data System (ADS)

    Post, Piia; Sepp, Mait

    2015-04-01

    Essential changes have taken place in atmospheric circulation over the Northern Atlantic in winter and spring during the second half of the 20th century. The winter temperature rise in Europe is frequently attributed to the intensification of zonal flow on the Northern Atlantic region and the same is valid for the Baltic Sea region. Intensification of zonal circulation and its expression through NAO and AO indices have been thoroughly studied, but less is known about mechanisms causing declination from the zonality of flow. Extremely cold weather in winter and spring in Baltic Sea region is related to the radiative cooling or advection of cold air masses. In both cases, the typical western flow is blocked and the region is directly influenced by atmospheric circulation conditions in the Arctic through the cold air advection events. Our aim is to study which large scale atmospheric circulation patterns are responsible for this kind of cold air advection to the Baltic Sea region in winter and spring (from December to May). The second task is to identify if this kind of circulation has become less frequent in the region under research beginning from the last half of the 20th century till now. Describing the atmospheric circulation patterns we use several classifications of atmospheric circulation on daily level. The domain of the classifications covers Atlantic-European sector of the Arctic, including area between Greenland and Novaya Zemlya archipelago. Manual classifications by Vangengeim-Girs and Dzerdzejevski are used, but also several newly calculated ones, that apply different classification methods from cost733class software. For the latter ones geopotential height fields at 500 hPa level from NCEP-NCAR reanalysis are classified for the period 1948-2013. The cold air advection events are determined by daily temperature drops by at least 3°C during 24 hours. The circulation types that bring advection of cold Arctic air to the Baltic Sea region are analysed in

  12. Macrozooplankton of the Arctic - The Kara Sea in relation to environmental conditions

    NASA Astrophysics Data System (ADS)

    Dvoretsky, Vladimir G.; Dvoretsky, Alexander G.

    2017-03-01

    The distribution, abundance, biomass and diversity of macrozooplankton were studied in relation to hydrological conditions in the Kara Sea during July-September 2012. Multivariate analysis of macrozooplankton density data identified a clear division between the community structure of the deepwater, shelf and estuarine zones. The first assemblage along the Novaya Zemlya Archipelago in the western part of the Kara Sea was characterized by high total abundance/biomass (80,450 ind. m-2/16.9 g dry mass m-2) and was dominated by Calanus glacialis, C. hyperboreus, C. finmarchicus and Metridia longa. The second assemblage in the central part of the Kara Sea was similar in species composition but differed in term of abundance and biomass (15,300 ind. m-2/2.7 g DM m-2). The lowest abundance/biomass (2130 ind. m-2/0.3 g DM m-2) was measured in the third assemblage, the Ob Shallow region, which was characterized by the presence of estuarine taxa and was heavily influenced by freshwater discharge. Parasagitta elegans, Mertensia ovum, Aglantha digitale, Aeginopsis laurentii, Dimophyes arctica and Clione limacina were present mainly as young stages suggesting reproduction of these species in July-August. Canonical correspondence analysis revealed that hydrological factors (salinity and temperature) and geographical variables (latitude, longitude and depth) were the main predictors of macrozooplankton community structures in the Kara Sea. Comparison of our data with other regions in the Arctic demonstrated similarity in the taxonomic composition and density of major large-bodied groups (i.e. amphipods, krill, medusae, pteropods, chaetognaths).

  13. Recent mass balance of Arctic glaciers derived from repeat-track ICESat altimetry (Invited)

    NASA Astrophysics Data System (ADS)

    Moholdt, G.; Nuth, C.; Hagen, J. M.; Wolken, G. J.; Gardner, A.

    2010-12-01

    The Arctic region is more affected by climate change than the lower latitudes. Glaciers and ice caps are sensitive indicators of climate change, and there is a high demand for more accurate quantifications of glacier changes in the Arctic. ICESat laser altimetry has been a popular tool for assessing recent elevation changes of the Greenland ice sheet. Other high Arctic glaciers have an equally dense coverage of ICESat tracks, but the quantity and quality of elevation comparisons are degraded due to smaller glacier sizes and steeper slopes. A methodological study at the Svalbard archipelago in the Norwegian Arctic has shown that it is feasible to obtain reasonable elevation change estimates from repeat-track ICESat altimetry (Moholdt et al., 2010). The best results were achieved using all available ICESat data in a joint analysis where surface slope and elevation change were estimated for homogeneous planes that were fitted to the data along each track. The good performance of the plane method implies that it can also be used in other Arctic regions of similar characteristics where accurate DEMs are typically not available. We present 2003-2009 elevation change rates for the Norwegian Arctic (Svalbard), the Russian Arctic (Novaya Zemlya, Severnaya Zemlya and Franz Josefs Land) and the Canadian Arctic (Queen Elizabeth Islands and Baffin Island). The glaciers and ice caps of these regions cover a total area of ~230 000 km2 which is about 30% of the world-wide glacier cover outside of the Greenland and Antarctic ice sheets. Most regions experience strong thinning at low elevations, while the pattern at higher elevations varies from slight thinning to slight thickening. There are also examples of local anomalous elevation changes due to unstable glacier dynamics, e.g. glacier surging. Hypsometric calculations are performed to calculate regional volume changes on a bi-annual time scale and over the entire ICESat period (2003-2009). Short-term variations in firn layer

  14. Modis LST as an Index of Summer Melt Conditions over Arctic Ice Caps

    NASA Astrophysics Data System (ADS)

    Geai, M. E.; Sharp, M. J.

    2011-12-01

    Despite the large area of glacier ice in the Arctic, very few in situ mass balance and air temperature measurements exist over Arctic ice caps. There is therefore a need to develop proxy records of summer melt conditions on these ice caps in order to identify spatial patterns and temporal trends in surface mass balance across the region. Analysis of Moderate Resolution Imaging Spectroradiometer (MODIS) derived land surface temperatures (LST) may provide a method to evaluate melt and climate trends over Arctic ice caps for the last decade. MODIS LST data were used to derive the seasonal mean of 8-day average values of daytime clear-sky surface temperature over 30 Arctic ice caps for each melt season from 2000 to 2010. LST was retrieved for a specified area within each individual ice cap, defined as the largest contiguous area of ice and snow within that ice cap. The melt season was defined as the period between the 10-year mean of melt onset and freeze-up dates derived from QuikScat. Given the potential biases introduced by the facts that a) LST data are available only for clear sky days and b) cloudiness likely varies substantially across the Arctic glaciated regions, there is a need to verify LST measurements against known changes in air temperature across all these regions. NCEP/NCAR R1 Reanalysis temperatures provide a single consistent dataset with which to evaluate air temperature trends. Ice caps in Alaska, the Canadian Arctic Archipelago (CAA) and Greenland display a common shift toward strong positive anomalies in the 2000's (0.45 to 1.2°C). The Iceland and Svalbard ice caps show weaker positive air temperature anomalies in the same period (0.38 to 0.4°C), while the Novaya Zemlya, Severnaya Zemlya and Franz Josef Land ice caps (Russia) display negative anomalies (-0.10 to -0.25°C). LST track the NCEP air temperature records at 700 hPa in the CAA (r2 0.6 to 0.96) and northern Svalbard (r2 0.6 to 0.76) only. This talk will explore whether the observed

  15. Living and dead benthic foraminiferal assemblages from bathyal environment in the Pontine Archipelago (Tyrrhenian Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Di Bella, Letizia; Frezza, Virgilio; Ingrassia, Michela; Latino Chiocci, Francesco; Martorelli, Eleonora

    2016-04-01

    The western Pontine Archipelago (Tyrrhenian Sea, Italy), located about 30 km away from the Italian Peninsula, is composed of three volcanic islands (Ponza, Palmarola and Zannone). Sedimentological and micropaleontological characterization of the infralittoral and circalittoral zones in the Pontine Archipelago was already been studied, whereas it is lacking for deeper environments. The present study shows the preliminary micropaleontological results carried out on samples collected in the bathyal zone (at 500 mwd) in the Ventotene basin. Sediment samples, high resolution multibeam bathymetry, biological and video data were acquired in order to characterise both the morphological and biological features of study area, during the research cruise "BOLLE 2014" carried out on June 2014 aboard to the R/V Urania. Sediment samples were collected with a multi-corer, that allowed sampling of the upper decimetre of the sediments column. Successively, each core was sliced horizontally every 1 cm from the top to the bottom. For micropaleontological analyses, all samples were stained with Rose Bengal to distinguish living and dead assemblages. For each interval of the core all living specimens and 200 dead benthic foraminifera were classified and counted. Diversity index (α-Fisher, Shannon indices) and Faunal Density (specimens/gr) were calculated to define the structure of the assemblage. A variable number of living benthic foraminifera (Rose Bengal-stained) were found in all core-intervals (7-155 tests), with the Faunal Density ranging from 3 to 82 specimens/gr. A total of 77 species are recognised from living benthic foraminiferal assemblages, with a range of 4-31 species found in each core-interval. The α-Fisher index ranges between 3.88 and 43.45, whereas Shannon index shows a more limited variability (1.28-2.92). Among the living foraminifera, calcareous imperforate tests are very abundant, with percentages ranging between 33.3 and 100%; perforate species are subordinate

  16. Estimates of tidal mixing in the Indonesian archipelago from multidisciplinary INDOMIX in-situ data

    NASA Astrophysics Data System (ADS)

    Koch-Larrouy, Ariane; Atmadipoera, Agus; van Beek, Pieter; Madec, Gurvan; Aucan, Jérôme; Lyard, Florent; Grelet, Jacques; Souhaut, Marc

    2015-12-01

    The Indonesian Mixing program (INDOMIX) was designed to quantify the very strong mixing that transforms Pacific waters into isohaline Indonesian Waters in the Indonesian archipelago. The turbulent dissipation rates and associated mixing were estimated and analyzed using a multidisciplinary approach that combines physical and geochemical in-situ observations: (1) direct measurements of the dissipation using a microstructure profiler, (2) use of density-based fine-scale methods applied to CTD and XCTD data, and (3) study of the vertical distribution of natural radionuclides (radium isotopes and actinium-227). Data were collected at five contrasting stations within the Indonesian archipelago, found above energetic straits or in relatively quiescent large basins. Strong instabilities, inversions of the density profiles and a very strong water mass transformation were observed. A wide range of dissipation values were obtained (between [10-10, 10-4] W kg-1) with spots of higher dissipation in the ocean interior correlated with a strong internal tide signal. Both the fine-scale and micro-scale methods allow us to identify very strong energy dissipation levels above the straits, ranging between [10-7, 10-4] W kg-1, in contrast to lower values at stations further away from the generation sites. The dissipation for the station located in the center of the Halmahera Sea ([10-9, 10-8] W kg-1) is stronger than for the Banda station ([10-11, 10-10] W kg-1), which is even further away from the generation sites. The three approaches agree relatively well and provide vertical eddy diffusivities values ranging between 5×10-4 and 5×10-1 m2 s-1, except in the Banda Sea where values are similar to the ones found in the open ocean (10-6 m2 s-1). CTD and XCTD profilers (deployed between stations) give estimates of dissipation all along the transit. It is found that enhanced mixing occurs preferentially above rough topography, such as in the Ombai Strait, the Halmahera Sea's northern

  17. Facies, Stratigraphic and Depositional Model of the Sediments in the Abrolhos Archipelago (Bahia, BRAZIL)

    NASA Astrophysics Data System (ADS)

    Matte, R. R.; Zambonato, E. E.

    2012-04-01

    Located in the Mucuri Basin on the continental shelf of southern Bahia state, northeast Brazil, about 70 km from the city of Caravelas,the Abrolhos archipelago is made up of five islands; Santa Barbara, Redonda, Siriba, Guarita and Sueste. The exhumed sediments in the Abrolhos archipelago are a rare record of the turbidite systems which fill the Brazilian Atlantic Basin, and are probably an unprecedented example of a plataform turbidite system (Dr. Mutti, personal communication). Despite the limited area, the outcrops display a wide facies variation produced by different depositional processes, and also allow for the observation of the layer geometries. Associated with such sedimentary rocks, the Abrolhos Volcanic Complex belongs stratigraphically to the Abrolhos Formation. These igneous rocks were dated by the Ar / Ar method, with ages ranging from 60 to 40 My, placing such Volcanic Complex between the Paleocene and Eocene. The sedimentary section is best exposed in the Santa Barbara and Redonda islands and altogether it is 70 m thick. The measured vertical sections show a good stratigraphic correlation between the rocks of the western portion of the first island and those of Redonda Island. However, there is no correlation between the eastern and western portions of Santa Barbara Island, since they are very likely interrupted by the igneous intrusion and possibly by faulting. The sedimentary stack consists of deposits with alternated regressive and transgressive episodes interpreted as high frequency sequences. The coarse facies, sandstones and conglomerates, with abrupt or erosive bases record regressive phases. On the other hand, finer sandstones and siltstones facies, which are partly bioturbated, correspond to phases of a little sediment supply. In the central and eastern portions of Santa Barbara Island, there is a trend of progradational stacking, while both in the western portion of Santa Barbara and in Redonda islands an agradational trend is observed

  18. Ciguatera fish poisoning: Incidence, health costs and risk perception on Moorea Island (Society archipelago, French Polynesia).

    PubMed

    Morin, Ewen; Gatti, Clémence; Bambridge, Tamatoa; Chinain, Mireille

    2016-12-01

    Ciguatera Fish Poisoning (CFP) is a non-bacterial seafood poisoning well characterized in the remote archipelagos of French Polynesia, yet poorly documented in the Society archipelago, most notably on Moorea, the second most populated island in French Polynesia, which counts a high proportion of fishermen fishing on a regular basis. To address this knowledge gap, a holistic study of the ciguatera issue was conducted on Moorea. First, ciguatera risk was analysed in terms of incidence rate, fish species most commonly involved and risk stratification in Moorea lagoon based on 2007-2013 epidemiological data. A mean incidence rate of 8 cases per 10,000 inhabitants for the study period and an average under-reporting rate of 54% were found. Taking into account hospitalization and medication fees, and loss of productive days, the health-related costs due to CFP were estimated to be USD $1613 and $749 for each reported and unreported case, respectively, with an overall cost of USD $241,847 for the study period. Comparison of the present status of CFP on Moorea with a risk map established in the late 1970's showed that the spatial distribution of the risk has stayed relatively stable in time, with the north shore of the island remaining the most prone to ciguatera. Evaluation of the current knowledge on CFP among different populations groups, i.e. fishermen, residents and visitors, was also conducted through direct and indirect interviews. About half of the fishermen interviewed were actually able to identify risky fishing areas. While, overall, the CFP risk perception in the fishing community of Moorea seemed accurate, although not scientifically complete, it was sufficient for the safe practice of their fishing activities. This may be due in part to adaptive responses adopted by 36% of the fishermen interviewed, such as the avoidance of either high-risk fishing sites or toxic species. At the residents and visitors' level, the study points out a striking lack of awareness

  19. Effects of boating activities on aquatic vegetation in the Stockholm archipelago, Baltic Sea

    NASA Astrophysics Data System (ADS)

    Eriksson, B. K.; Sandström, A.; Isæus, M.; Schreiber, H.; Karås, P.

    2004-10-01

    The aquatic vegetation in 44 similar shallow and sheltered inlets exposed to different kinds of disturbances by boating was studied in a rocky archipelago in the Baltic Sea. The results indicate that both recreational boating activities and traffic by medium sized ferryboats may cause significant changes in community composition and have significant negative effects on species richness and the development of the macrophytic vegetation at greater depth. Changes in inlet morphology by dredging and increases in resuspension and turbidity by wave-action from boats were most probably the major factors contributing to the demonstrated differences in the vegetation between inlets. In inlets used as harbours for private boats (marinas) or adjacent to ferryboat routes, vegetation cover and species richness declined significantly more with depth than in reference inlets not exposed to disturbance by boating activities. In marinas, turbidity was significantly higher than in reference inlets. Accordingly, a canonical correspondence analysis showed that the abundance of species sensitive to poor light conditions, such as Chara spp. and Ruppia spp. were negatively correlated with marinas while Myriophyllum spicatum and Ceratophyllum demersum that are common in nutrient rich turbid habitats were positively correlated with marinas. Mechanical disturbance by propellers may also have contributed to the results, disfavouring Potamogeton pectinatus compared to similar caulescent species in marinas. Chara tomentosa and Najas marina that are exposure sensitive mud thriving species were negatively correlated with inlets adjacent to ferryboat routes, while the macroalga Fucus vesiculosus that is dependent on clean substrate for successful recruitment was positively correlated with inlets adjacent to ferryboat routes. It is important to explore further the effects of boating activities in these habitat types, since the studied inlets sustain a high diversity of both plants and

  20. Archaeological implications of a widespread 13th Century tephra marker across the central Indonesian Archipelago

    NASA Astrophysics Data System (ADS)

    Alloway, Brent V.; Andreastuti, Supriyati; Setiawan, Ruly; Miksic, John; Hua, Quan

    2017-01-01

    Despite the occurrence of exceptionally large eruptions in the Indonesian Archipelago in recent historic times (i.e. Krakatoa 1883, Tambora 1815), no historic tephra beds have been widely identified in the terrestrial realm that could facilitate the correlation of equivalent aged sequences and/or archaeological remains. This study has identified one such tephra bed of 13th Century age that can be correlated throughout central-east Java and now can be unequivocally correlated with the Samalas 1257 A.D. tephra recently described from Lombok. The occurrence of this historic tephra marker extending ≥650 km west from its eruptive source provides the first opportunity to effect inter-regional correlation over large swathes of central Indonesia. It remains entirely conceivable that in the aftermath of this exceptionally large eruptive event there was considerable westward disruption to subsistence agriculture and trade, food shortages and famine, dislocation of affected populations and socio-political unrest on a scale that equalled or exceeded the catastrophic effects documented from the more recent Tambora 1815 A.D. eruption. Indeed the effects of this mid-13th Century eruption can be registered globally in a variety of records from Antarctica, Europe, Middle East and the Americas. Unfortunately, archaeological evidence indicating such disruption in mid-13th Century Indonesia is yet to be deciphered from the so-far sparse accounts and inscriptions of that time. However, this paucity of evidence does not diminish the utility of this widespread tephra bed as a unique chronostratigraphic marker for archaeological studies across large areas of central Indonesia.

  1. Indirect food web interactions: sea otters and kelp forest fishes in the Aleutian archipelago.

    PubMed

    Reisewitz, Shauna E; Estes, James A; Simenstad, Charles A

    2006-01-01

    Although trophic cascades-the effect of apex predators on progressively lower trophic level species through top-down forcing-have been demonstrated in diverse ecosystems, the broader potential influences of trophic cascades on other species and ecosystem processes are not well studied. We used the overexploitation, recovery and subsequent collapse of sea otter (Enhydra lutris) populations in the Aleutian archipelago to explore if and how the abundance and diet of kelp forest fishes are influenced by a trophic cascade linking sea otters with sea urchins and fleshy macroalgae. We measured the abundance of sea urchins (biomass density), kelp (numerical density) and fish (Catch per unit effort) at four islands in the mid-1980s (when otters were abundant at two of the islands and rare at the two others) and in 2000 (after otters had become rare at all four islands). Our fish studies focused on rock greenling (Hexagrammos lagocephalus), the numerically dominant species in this region. In the mid-1980s, the two islands with high-density otter populations supported dense kelp forests, relatively few urchins, and abundant rock greenling whereas the opposite pattern (abundant urchins, sparse kelp forests, and relatively few rock greenling) occurred at islands where otters were rare. In the 2000, the abundances of urchins, kelp and greenling were grossly unchanged at islands where otters were initially rare but had shifted to the characteristic pattern of otter-free systems at islands where otters were initially abundant. Significant changes in greenling diet occurred between the mid-1980s and the 2000 although the reasons for these changes were difficult to assess because of strong island-specific effects. Whereas urchin-dominated communities supported more diverse fish assemblages than kelp-dominated communities, this was not a simple effect of the otter-induced trophic cascade because all islands supported more diverse fish assemblages in 2000 than in the mid-1980s.

  2. Bacterial Community Composition and Potential Driving Factors in Different Reef Habitats of the Spermonde Archipelago, Indonesia

    PubMed Central

    Kegler, Hauke F.; Lukman, Muhammad; Teichberg, Mirta; Plass-Johnson, Jeremiah; Hassenrück, Christiane; Wild, Christian; Gärdes, Astrid

    2017-01-01

    Coastal eutrophication is a key driver of shifts in bacterial communities on coral reefs. With fringing and patch reefs at varying distances from the coast the Spermonde Archipelago in southern Sulawesi, Indonesia offers ideal conditions to study the effects of coastal eutrophication along a spatially defined gradient. The present study investigated bacterial community composition of three coral reef habitats: the water column, sediments, and mucus of the hard coral genus Fungia, along that cross-shelf environmental and water quality gradient. The main research questions were: (1) How do water quality and bacterial community composition change along a coastal shelf gradient? (2) Which water quality parameters influence bacterial community composition? (3) Is there a difference in bacterial community composition among the investigated habitats? For this purpose, a range of key water parameters were measured at eight stations in distances from 2 to 55 km from urban Makassar. This was supplemented by sampling of bacterial communities of important microbial habitats using 454 pyrosequencing. Findings revealed that the population center Makassar had a strong effect on the concentrations of Chlorophyll a, suspended particulate matter (SPM), and transparent exopolymer particles (TEP), which were all significantly elevated at the inshore compared the other seven sites. Shifts in the bacterial communities were specific to each sampled habitat. Two OTUs, belonging to the genera Escherichia/Shigella (Gammaproteobacteria) and Ralstonia (Betaproteobacteria), respectively, both dominated the bacterial community composition of the both size fractions of the water column and coral mucus. The sampled reef sediments were more diverse, and no single OTUs was dominant. There was no gradual shift in bacterial classes or OTUs within the sampled habitats. In addition, we observed very distinct communities between the investigated habitats. Our data show strong changes in the bacterial

  3. Petrology of ultramafic xenoliths in Cenozoic alkaline rocks of northern Madagascar (Nosy Be Archipelago)

    NASA Astrophysics Data System (ADS)

    Rocco, Ivana; Lustrino, Michele; Zanetti, Alberto; Morra, Vincenzo; Melluso, Leone

    2013-01-01

    Late Miocene basanites of Nosy Be and Nosy Sakatia islands (Nosy Be Archipelago, northern Madagascar) carry spinel-facies anhydrous ultramafic xenoliths (lherzolites, harzburgites and wehrlites). Geothermobarometric estimates indicate that these xenoliths derive from shallow mantle depths of 35-40 km, with those from Nosy Be island showing equilibration T (averages in the range of 945-985 °C) lower than the Nosy Sakatia analogues (averages ranging from 1010 to 1110 °C). One Nosy Sakatia mantle xenolith exhibits relatively fertile lherzolite composition, with trace and major element mineral chemistry consistent with a residual character after low degrees (1-2%) of mafic melt extraction. We interpret this composition as that resembling a depleted mantle (DM)-like lithospheric composition before metasomatic overprints. The other lherzolites and harzburgites display petrochemical characters consistent with variable extent of partial melting (up to 18%), associated with pronounced metasomatic overprints caused by migrating melts, as highlighted by enrichments in highly incompatible trace elements (e.g. light rare earth elements, LREE and Sr), together with the abundant occurrence of wehrlitic lithologies. The variability of petrochemical features points to different styles of metasomatism and metasomatic agents. The estimated composition of the parental melts of wehrlites matches that of host basanites. The combination of this evidence with the petrographic features, characterized by coarse-granular to porphyroclastic textures and by the presence of olivine without kink-banding, suggests that wehrlites are veins or pockets of high pressure cumulates within the mantle peridotite. The same melts also metasomatized via porous-flow percolation some lherzolites and harzburgites. Distinctly, a group of lherzolites and harzburgites was metasomatized by a different alkaline melt having markedly lower incompatible trace element contents. Late infiltration of metasomatic fluids

  4. Towards Stochastic Optimization-Based Electric Vehicle Penetration in a Novel Archipelago Microgrid.

    PubMed

    Yang, Qingyu; An, Dou; Yu, Wei; Tan, Zhengan; Yang, Xinyu

    2016-06-17

    Due to the advantage of avoiding upstream disturbance and voltage fluctuation from a power transmission system, Islanded Micro-Grids (IMG) have attracted much attention. In this paper, we first propose a novel self-sufficient Cyber-Physical System (CPS) supported by Internet of Things (IoT) techniques, namely "archipelago micro-grid (MG)", which integrates the power grid and sensor networks to make the grid operation effective and is comprised of multiple MGs while disconnected with the utility grid. The Electric Vehicles (EVs) are used to replace a portion of Conventional Vehicles (CVs) to reduce CO 2 emission and operation cost. Nonetheless, the intermittent nature and uncertainty of Renewable Energy Sources (RESs) remain a challenging issue in managing energy resources in the system. To address these issues, we formalize the optimal EV penetration problem as a two-stage Stochastic Optimal Penetration (SOP) model, which aims to minimize the emission and operation cost in the system. Uncertainties coming from RESs (e.g., wind, solar, and load demand) are considered in the stochastic model and random parameters to represent those uncertainties are captured by the Monte Carlo-based method. To enable the reasonable deployment of EVs in each MGs, we develop two scheduling schemes, namely Unlimited Coordinated Scheme (UCS) and Limited Coordinated Scheme (LCS), respectively. An extensive simulation study based on a modified 9 bus system with three MGs has been carried out to show the effectiveness of our proposed schemes. The evaluation data indicates that our proposed strategy can reduce both the environmental pollution created by CO 2 emissions and operation costs in UCS and LCS.

  5. Towards Stochastic Optimization-Based Electric Vehicle Penetration in a Novel Archipelago Microgrid

    PubMed Central

    Yang, Qingyu; An, Dou; Yu, Wei; Tan, Zhengan; Yang, Xinyu

    2016-01-01

    Due to the advantage of avoiding upstream disturbance and voltage fluctuation from a power transmission system, Islanded Micro-Grids (IMG) have attracted much attention. In this paper, we first propose a novel self-sufficient Cyber-Physical System (CPS) supported by Internet of Things (IoT) techniques, namely “archipelago micro-grid (MG)”, which integrates the power grid and sensor networks to make the grid operation effective and is comprised of multiple MGs while disconnected with the utility grid. The Electric Vehicles (EVs) are used to replace a portion of Conventional Vehicles (CVs) to reduce CO2 emission and operation cost. Nonetheless, the intermittent nature and uncertainty of Renewable Energy Sources (RESs) remain a challenging issue in managing energy resources in the system. To address these issues, we formalize the optimal EV penetration problem as a two-stage Stochastic Optimal Penetration (SOP) model, which aims to minimize the emission and operation cost in the system. Uncertainties coming from RESs (e.g., wind, solar, and load demand) are considered in the stochastic model and random parameters to represent those uncertainties are captured by the Monte Carlo-based method. To enable the reasonable deployment of EVs in each MGs, we develop two scheduling schemes, namely Unlimited Coordinated Scheme (UCS) and Limited Coordinated Scheme (LCS), respectively. An extensive simulation study based on a modified 9 bus system with three MGs has been carried out to show the effectiveness of our proposed schemes. The evaluation data indicates that our proposed strategy can reduce both the environmental pollution created by CO2 emissions and operation costs in UCS and LCS. PMID:27322281

  6. Fe-binding dissolved organic ligands near the Kerguelen Archipelago in the Southern Ocean (Indian sector)

    NASA Astrophysics Data System (ADS)

    Gerringa, L. J. A.; Blain, S.; Laan, P.; Sarthou, G.; Veldhuis, M. J. W.; Brussaard, C. P. D.; Viollier, E.; Timmermans, K. R.

    2008-03-01

    During the Kerguelen Ocean and Plateau compared Study (KEOPS; January-February 2005) cruise, the area southeast of the Kerguelen Archipelago in the Indian sector of the Southern Ocean was investigated to identify the mechanisms of natural iron fertilization of the Kerguelen Plateau. In this study, the organic speciation of Fe is described. Samples were determined immediately on board using competing ligand-adsorptive cathodic stripping voltammetry (CL-AdCSV). The dissolved organic ligands were always in excess of the dissolved Fe concentration, increasing the residence time in the water column and the potential availability for phytoplankton. The concentration of the dissolved organic ligands ranged from 0.44 to 1.61 nEq of M Fe (=complexation site for Fe), with an average concentration of 0.91 nEq of M Fe (S.D.=0.28, n=113) and a mean logarithm of conditional stability constant (log K') of 21.7 (S.D.=0.28, n=113). A second weaker dissolved organic ligand group was detected in 32% of the samples, with Fe-binding characteristics at the edge of the detection window of the applied method. The occurrence of the highest concentrations of dissolved organic ligands in the wind-mixed surface layer and near the sediment at the bottom of the water column indicated that both phytoplankton and the sediment act as sources. Both sources are in concert with the general conclusions from the KEOPS research on the sources of Fe, where Fe was regenerated, organic Fe-binding ligands were formed in the upper layers, and both Fe and ligands were supplied by the sediment.

  7. Temporal Variation in Fish Mercury Concentrations within Lakes from the Western Aleutian Archipelago, Alaska

    PubMed Central

    Kenney, Leah A.; Eagles-Smith, Collin A.; Ackerman, Joshua T.; von Hippel, Frank A.

    2014-01-01

    We assessed temporal variation in mercury (Hg) concentrations of threespine stickleback (Gasterosteus aculeatus) from Agattu Island, Aleutian Archipelago, Alaska. Total Hg concentrations in whole-bodied stickleback were measured at two-week intervals from two sites in each of two lakes from June 1 to August 10, 2011 during the time period when lakes were ice-free. Across all sites and sampling events, stickleback Hg concentrations ranged from 0.37–1.07 µg/g dry weight (dw), with a mean (± SE) of 0.55±0.01 µg/g dw. Mean fish Hg concentrations declined by 9% during the study period, from 0.57±0.01 µg/g dw in early June to 0.52±0.01 µg/g dw in mid-August. Mean fish Hg concentrations were 6% higher in Loon Lake (0.56±0.01 µg/g dw) than in Lake 696 (0.53±0.01 µg/g dw), and 4% higher in males (0.56±0.01 µg/g dw) than in females (0.54±0.01 µg/g dw). Loon Lake was distinguished from Lake 696 by the presence of piscivorous waterbirds during the breeding season. Mercury concentrations in stickleback from Agattu Island were higher than would be expected for an area without known point sources of Hg pollution, and high enough to be of concern to the health of piscivorous wildlife. PMID:25029042

  8. Pelagic seabird surveys in the Tuamotu and Gambier Archipelagos, French Polynesia

    USGS Publications Warehouse

    Vanderwerf, Eric A.; Pierce, Ray J.; Gill, Verena A.; Wragg, Graham; Raust, Philippe; Tibbitts, T. Lee

    2006-01-01

    We conducted pelagic seabird surveys in the Gambier and Tuamotu Archipelagos in the southeastern Pacific Ocean totaling 40 hours during 7-27 March 2003 and 22.5 hours during 22-27 July 2001. We used a 300-m-wide strip transect to estimate seabird density, and we estimated relative abundance of birds at all distances. In 2001, we observed a total of 326 birds of 18 species. The mean relative abundance of all birds was 14.3 ?? 3.1/h. Red-footed Booby Sula sula was the most abundant species (5.6/h), followed by White Tern Gygis alba (3.4/h), and Great Crested or Swift Tern Sterna bergii (1.2/h). In 2003, we observed a total of 1463 birds of 25 species. The mean relative abundance of all birds was 36.6 ?? 11.4/h and the mean density of all birds was 4.14 ?? 0.72/km2. Brown Noddy Anous stolidus was the most abundant species (17.6/h, 1.5/km2), followed by White Tern (8.4/h, 1.3/km2), and Red-footed Booby (4.6/h, 0.8/km2). Several globally or locally rare species were observed infrequently, including Phoenix Petrel Pterodroma alba (0.1/h, 0.03/km2). Distribution of birds was uneven, with long periods of no birds punctuated by occasional feeding flocks. In 2003, species diversity was related to length of observation period, with more species observed on longer segments (r2 = 0.58, F1.5 = 6.03, P = 0.05). Although the duration and extent of our surveys were limited, these data are valuable because little published information is available on pelagic seabirds in southeastern Polynesia.

  9. Late Pliocene and Quaternary Eurasian locust infestations in the Canary Archipelago

    USGS Publications Warehouse

    Meco, J.; Muhs, D.R.; Fontugne, M.; Ramos, A.J.; Lomoschitz, A.; Patterson, D.

    2011-01-01

    The Canary Archipelago has long been a sensitive location to record climate changes of the past. Interbedded with its basalt lavas are marine deposits from the principal Pleistocene interglacials, as well as aeolian sands with intercalated palaeosols. The palaeosols contain African dust and innumerable relict egg pods of a temperate-region locust (cf. Dociostaurus maroccanusThunberg 1815). New ecological and stratigraphical information reveals the geological history of locust plagues (or infestations) and their palaeoclimatic significance. Here, we show that the first arrival of the plagues to the Canary Islands from Africa took place near the end of the Pliocene, ca. 3Ma, and reappeared with immense strength during the middle Late Pleistocene preceding MIS (marine isotope stage) 11 (ca. 420ka), MIS 5.5 (ca. 125ka) and probably during other warm interglacials of the late Middle Pleistocene and the Late Pleistocene. During the Early Holocene, locust plagues may have coincided with a brief cool period in the current interglacial. Climatically, locust plagues on the Canaries are a link in the chain of full-glacial arid-cold climate (calcareous dunes), early interglacial arid-sub-humid climate (African dust inputs and locust plagues), peak interglacial warm-humid climate (marine deposits with Senegalese fauna), transitional arid-temperate climate (pedogenic calcretes), and again full-glacial arid-cold climate (calcareous dunes) oscillations. During the principal interglacials of the Pleistocene, the Canary Islands recorded the migrations of warm Senegalese marine faunas to the north, crossing latitudes in the Euro-African Atlantic. However, this northward marine faunal migration was preceded in the terrestrial realm by interglacial infestations of locusts. ??? Locust plagues, Canary Islands, Late Pliocene, Pleistocene, Holocene, palaeoclimatology. ?? 2010 The Authors, Lethaia ?? 2010 The Lethaia Foundation.

  10. Vector Surveillance for Dengue Virus Detection in the Archipelago of Fernando de Noronha, Brazil.

    PubMed

    Barbosa, P P; Guedes, D R D; Melo-Santos, M A V; Cordeiro, M T; Acioli, R V; Batista, C A V; Gonçalves, L S M; Souza, M F M; Araújo, Y V; Magalhães, F J R; Regis, L; Ayres, C F J

    2016-05-01

    Aedes aegypti (L.) has become an efficient vector of important arboviruses due to its anthropophilic and domiciliary behaviors. Since the 1980s, dengue affects thousands of people every year in Brazil; in Fernando de Noronha (FN), a touristic archipelago, dengue cases have occurred since 2001. Once Ae. aegypti populations are well established in the inhabited areas of FN, the threat of dengue or another arbovirus epidemic is continuously imminent. This study aimed to monitor the DENV serotypes in mosquito samples collected in FN, where at least one resident was clinically diagnosed as dengue patient. Entomological surveillance was conducted in 2011 and 2012. Mosquitoes were sorted by sex and location and were stored in pools. DENV detection was performed using polymerase chain reaction with reverse transcription (RT-PCR) and the Platelia Dengue NS1 Ag. RNA integrity was checked by RT-PCR using rpL8 primers, and the minimum infection rate (MIR) was calculated. In total, 339 pools were analyzed, and only one was positive (DENV-1) by Multiplex RT-PCR (MIR = 1.53). When considering only pools with RNA integrity, the MIR was 2.92. Using the Platelia kit, the MIR was 9.18 (considering all the pools) and 17.54 (only 140 pools with RNA integrity). Our results showed the importance of a constant entomological surveillance in that area, the need to improve storage and transportation protocols, and an endogenous control in the RT-PCR to avoid false-negative results. Finally, our study indicated that the NS1-Ag detection was the most sensitive method and should be used routinely for DENV surveillance in mosquitoes if the serotype identification is not required. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. The archipelago of Fernando de Noronha: an intriguing malformed toad hotspot in South America.

    PubMed

    Toledo, Luís Felipe; Ribeiro, Ricardo S

    2009-09-01

    Malformed anurans raise concern among scientists, because deformities may relate to the recent global crisis among amphibian populations, although declining populations also may be associated with other causes (e.g., diseases, over-exploitation, and land use/land cover change). We examined a sample of toads (Rhinella jimi, Bufonidae) from an introduced population in the Archipelago of Fernando de Noronha, Brazil where malformations of anurans were thought to be high. Our sample of 159 specimens from the site revealed that 44.6% of all specimens had one or more malformations. Incidence of malformed toads on the mainland sites was substantially lower: 10.5% at Itamaracá, and 3.7% at Propriá. We describe the malformations observed, including six undescribed types of malformation of anurans, and we pose possible hypotheses to explain this high incidence of malformed toads. In addition to existing hypotheses, we suggest for the first time the hypothesis that lack of predation pressures contributes to numbers of malformed toads. We indicate the need of specific studies to understand the causes of malformations in the R. jimi population of Fernando de Noronha, which is thought to be extreme foci of malformed amphibians in the world. Our results may improve local conservation action plans as this is an alien population that may be affecting endemic fauna, and may affect populations in other parts of the world, because toad species of the genus Rhinella are recognized as exceptional colonizers. More importantly, unknown variables in these toads' environment are evidently affecting toads during development, which should be a concern for all species that inhabit the area, perhaps even humans.

  12. New Ulvaceae (Ulvophyceae, Chlorophyta) from mesophotic ecosystems across the Hawaiian Archipelago.

    PubMed

    Spalding, Heather L; Conklin, Kimberly Y; Smith, Celia M; O'Kelly, Charles J; Sherwood, Alison R

    2016-02-01

    Ulvalean algae (Chlorophyta) are most commonly described from intertidal and shallow subtidal marine environments worldwide, but are less well known from mesophotic environments. Their morphological simplicity and phenotypic plasticity make accurate species determinations difficult, even at the generic level. Here, we describe the mesophotic Ulvales species composition from 13 locations across 2,300 km of the Hawaiian Archipelago. Twenty-eight representative Ulvales specimens from 64 to 125 m depths were collected using technical diving, submersibles, and remotely operated vehicles. Morphological and molecular characters suggest that mesophotic Ulvales in Hawaiian waters form unique communities comprising four species within the genera Ulva and Umbraulva, each with discrete geographic and/or depth-related distributional patterns. Three genetically distinct taxa are supported by both plastid (rbcL and tufA) and nuclear (ITS1) markers, and are presented here as new species: Umbraulva kaloakulau, Ulva ohiohilulu, and Ulva iliohaha. We also propose a new Umbraulva species (Umbraulva kuaweuweu), which is closely related to subtidal records from New Zealand and Australia, but not formally described. To our knowledge, these are the first marine species descriptions from Hawai'i resulting from the collaboration of traditional Hawaiian nomenclature specialists, cultural practitioners and scientists. The difficulty of finding reliable diagnostic morphological characters for these species reflects a common problem worldwide of achieving accurate identification of ulvalean taxa using solely morphological criteria. Mesophotic Ulvales appear to be distinct from shallow-water populations in Hawai'i, but their degree of similarity to mesophotic floras in other locations in the Pacific remains unknown.

  13. Patterns of Coral Disease across the Hawaiian Archipelago: Relating Disease to Environment

    PubMed Central

    Aeby, Greta S.; Williams, Gareth J.; Franklin, Erik C.; Kenyon, Jean; Cox, Evelyn F.; Coles, Steve; Work, Thierry M.

    2011-01-01

    In Hawaii, coral reefs occur across a gradient of biological (host abundance), climatic (sea surface temperature anomalies) and anthropogenic conditions from the human-impacted reefs of the main Hawaiian Islands (MHI) to the pristine reefs of the northwestern Hawaiian Islands (NWHI). Coral disease surveys were conducted at 142 sites from across the Archipelago and disease patterns examined. Twelve diseases were recorded from three coral genera (Porites, Montipora, Acropora) with Porites having the highest prevalence. Porites growth anomalies (PorGAs) were significantly more prevalent within and indicative of reefs in the MHI and Porites trematodiasis (PorTrm) was significantly more prevalent within and indicative of reefs in the NWHI. Porites tissue loss syndrome (PorTLS) was also important in driving regional differences but that relationship was less clear. These results highlight the importance of understanding disease ecology when interpreting patterns of disease occurrence. PorTrm is caused by a parasitic flatworm that utilizes multiple hosts during its life cycle (fish, mollusk and coral). All three hosts must be present for the disease to occur and higher host abundance leads to higher disease prevalence. Thus, a high prevalence of PorTrm on Hawaiian reefs would be an indicator of a healthy coral reef ecosystem. In contrast, the high occurrence of PorGAs within the MHI suggests that PorGAs are related, directly or indirectly, to some environmental co-factor associated with increased human population sizes. Focusing on the three indicator diseases (PorGAs, PorTrm, PorTLS) we used statistical modeling to examine the underlying associations between disease prevalence and 14 different predictor variables (biotic and abiotic). All three diseases showed positive associations with host abundance and negative associations with thermal stress. The association with human population density differed among disease states with PorGAs showing a positive and PorTrm showing

  14. Multi-decadal frontal change rates of tidewater glaciers in the Canadian Arctic Archipelago

    NASA Astrophysics Data System (ADS)

    Cook, Alison; Copland, Luke; Stokes, Chris; Bentley, Mike

    2017-04-01

    Recent studies of post-2000 observational data have shown variability in the dynamic ice discharge of tidewater glaciers throughout the Canadian Arctic Archipelago (CAA). Expanding this to all tidewater glaciers in the region on a decadal time scale using earlier records can help identify when glacier retreat began, and determine longer-term temporal trends in mass balance. Our study shows that over 94% of 300 tidewater glaciers in the CAA (from southern Baffin Island to Ellesmere Island, excluding those on the northern coast) have retreated since the earliest observational records (aerial photographs acquired in 1958-1960). Mean overall length change rate of the 211 glaciers in the Queen Elizabeth Islands (QEI) is -9.3 ma-1 (± 1.38 SE), and of the 89 glaciers on Baffin and Bylot Islands (BBI) is -7.1 ma-1 (± 0.72 SE). Mean frontal widths of tidewater glaciers in the QEI are greater than those on islands to the south, resulting in greater mean area loss from this region. Each glacier has 6 frontal positions digitised from a range of image sources at approximately decadal intervals. Length change rates have been calculated across each time interval for each glacier, based on area changes divided by glacier frontal width. Results indicate a similar temporal pattern throughout the region, whereby glaciers show minimal change in early years with retreat rates slowly increasing, followed by acceleration in retreat rates since the late 1990s. Mean change rates in the QEI and BBI in the 1960s were -6.92 ma-1 and -0.51 ma-1 respectively, increasing to -28.96 ma-1 and -24.84 ma-1 since 2010. The same trend (at differing magnitudes) has been observed within each latitudinal degree band, and for glaciers of differing frontal widths. Further observations of glacier changes and links to climate change are revealed on the poster.

  15. Molecular phylogeny of Banza (Orthoptera: Tettigoniidae), the endemic katydids of the Hawaiian Archipelago.

    PubMed

    Shapiro, L H; Strazanac, J S; Roderick, G K

    2006-10-01

    The extant endemic katydids (Orthoptera: Tettigoniidae) of the Hawaiian Archipelago include one to three species per high island and a single species on Nihoa, all currently placed in the genus Banza. These acoustic insects provide an excellent opportunity for investigating the evolution of reproductive isolation and speciation, but such studies require an understanding of phylogenetic relationships within the group. We use maximum parsimony, likelihood-based Bayesian inference, and maximum likelihood to infer phylogenetic relationships among these taxa, based on approximately 2kb of mitochondrial cytochrome oxidase I and cytochrome b. Our results strongly support two distinct high island clades: one clade ("Clade I") composed of species from Kauai, Oahu, Molokai, and Lanai and another clade ("Clade II") composed of species from Maui and Hawaii (Banza unica, from Oahu, may be basal to both these clades, but its placement is not well resolved). Within these clades, some inferred relationships are strongly supported, such as the sister status of B. kauaiensis (Kauai) and B. parvula (Oahu) within Clade I, but other relationships remain more ambiguous, such as the relative position of B. brunnea (Maui) within Clade II. Although a detailed reconstruction of the historical biogeography of the Hawaiian katydids is difficult, we use our genetic data combined with the known geological history of the Hawaiian Islands to set limits on plausible historical scenarios for diversification of this group. Beyond these historical biogeographic inferences, our results indicate possible cryptic speciation on both Oahu and Hawaii, as well as what may be unusually high average rates of nucleotide substitution. The present work sets the stage for future genetic and experimental investigations of this group.

  16. Multiscaling statistics of high frequency global solar radiation data in the Guadeloupean Archipelago

    NASA Astrophysics Data System (ADS)

    Calif, R.; Schmitt, F. G.; Huang, Y.; Soubdhan, T.

    2013-12-01

    The part of the solar power production from photovoltaiccs systems is constantly increasing in the electric grids. Solar energy converter devices such as photovoltaic cells are very sensitive to instantaneous solar radiation fluctuations. Thus rapid variation of solar radiation due to changes in the local meteorological condition can induce large amplitude fluctuations of the produced electrical power and reduce the overall efficiency of the system. When large amount of photovoltaic electricity is send into a weak or small electricity network such as island network, the electric grid security can be in jeopardy due to these power fluctuations. The integration of this energy into the electrical network remains a major challenge, due to the high variability of solar radiation in time and space. To palliate these difficulties, it is essential to identify the characteristic of these fluctuations in order to anticipate the eventuality of power shortage or power surge. A good knowledge of the intermittency of global solar radiation is crucial for selecting the location of a solar power plant and predicting the generation of electricity. This work presents a multifractal analysis study of 367 daily global solar radiation sequences measured with a sampling rate of 1 Hz over one year at Guadeloupean Archipelago (French West Indies) located at 16o15'N latitude and 60o30'W longitude. The mean power spectrum computed follows a power law behaviour close to the Kolmogorov spectrum. The intermittent and multifractal properties of global solar radiation data are investigated using several methods. Under this basis, a characterization for each day using three multifractal parameters is proposed.

  17. Multi-event behavior of El Golfo landslide (El Hierro Island, Canary Archipelago)

    NASA Astrophysics Data System (ADS)

    León, Ricardo; Biain, Ander; Urgeles, Roger; Somoza, Luis; Ferrer, Mercedes; García-Crespo, Jesús; Francisco Mediato, José; Galindo, Inés; Yepes, Jorge; Gimenez-Moreno, Julia

    2017-04-01

    Based on the re-interpretation of a vast onshore-offshore data set, a new morpho-structural characterization of the El Golfo giant landslide in the island of El Hierro (Canary Archipelago, Spain) is presented. Offshore multibeam echosounder data, chirp sub-bottom profiles, multichannel seismic reflection data and onshore information from water wells and galleries have been analyzed to determine the nature of the event. The subaerial headscarp shows a non-continuous arcuate profile formed by two nested semi-circular amphitheaters that extend offshore along a smooth chute, suggesting the occurrence of at least two large retrogressive events. Channels/gullies and escarpments developed along the submarine sector of the scar also indicate smaller-scale events and predominance of sediment bypass. At the base of submerged island, two subunits within the related submarine mass transport deposit (MTD) are identified on multichannel seismic reflection profiles confirming the multi-event nature of the landslide. The MTD, identified as a debris avalanche, has a total estimated volume of 318 km3: 84 km3 and 234 km3, for the lower and upper subunits respectively. Data from wells and galleries show abrasion platforms with beach deposits at sea-level (0 masl) formed after the landslide scar and buried by the El Golfo post-collapse infill lavas, suggesting an age at least older than 23.5-82.5 ka for the landslide. This work has been supported by the projects IGCP-640 S4SLIDE, High resolution seabed mapping EASME/EMFF/2016/005 and CTM2010-09496-E. Keywords: Submarine landslides, volcanic islands, debris avalanche, Canary Islands

  18. An Example of Inverse Magnetic Fabric in a Lava Pile From the Kerguelen Archipelago

    NASA Astrophysics Data System (ADS)

    Plenier, G.; Bascou, J.; Gattacceca, J.; Camps, P.; Rochette, P.

    2003-12-01

    Because of their low degree of anisotropy associated with a relatively high magnetic susceptibility, AMS measurements of lava flows often provide scattered results and a large number of sample is needed to well define the mean directions. However, the use of complementary AMS methods combined with other technics allow to infer flowing directions of lava piles. Such a study was performed on six volcanic sections (9 up to 20 lava flows) from the Kerguelen Archipelago(southern Indian Ocean) in order to complete regional geological observations of Nougier (1970) and identify the locations of the different eruptive centers. Unfortunately, one of these sequences, the Mont de la RabouillŠre, yielded an unexpected inverse fabric which did not allowed us to undoubtly interpret its flowing direction. We thus present a detailed analysis of this particular section including an additional AMS study on the same samples but at a demagnetized state. To complete this approach, we determined the anhysteretic remanent anisotropy (ARA) of theses samples to compare the magnetic fabrics obtained. Also further rock magnetic studies were performed. Normal and high resolution FORC analysis of one sample per flow were realized in order to detect eventual characteristic signatures associated with the inverse fabric. Endly, an Electron BackScattered Diffraction analysis (EBSD) of one thin section allowed to determine the cristalline orientation of the plagioclases to check its relation with the magnetic signal. Surprisingly, the [001] axis of the plagioclase minerals was found to be aligned with the mean kmax determined using the AMS. The study is still on progress but our preliminary interpretations indicate that the inverse magnetic fabric can be used to infer a confident flowing direction for this section. J. Nougier, 1970. Contribution a l'etude geologique et geomorphologique des iles Kerguelen. C.N.F.R.A., Vol 27, 2 tomes, 440pp and 256pp

  19. The volcanic-subvolcanic rocks of the fernando de noronha archipelago, southern atlantic ocean: Mineral chemistry

    NASA Astrophysics Data System (ADS)

    Lopes, Rosana Peporine; Ulbrich, Mabel N. Costas; Ulbrich, Horstpeter

    2014-12-01

    Fernando de Noronha archipelago presents an older Remédios Formation with subvolcanic intrusions, belonging to two different alkaline series, the sodic (undersaturated: basanites, tephrites, essexites, tephriphonolites, phonolites), and potassic ones (mildly undersaturated to silicic, with alkali basalts, basaltic trachyandesites, trachyandesites, trachytes), and lamprophyres. The upper Quixaba Formation presents nephelinite flows and basanites. A third minor unit, São José, is constituted by basanites carrying mantle xenoliths. Magnesian olivines occur in the Remédios basanites and alkali basalts, and in nephelinites. Melilites are present as groundmass grains in melilite melanephelinites (MEM). Clinopyroxenes (cpx) are mostly salites to titaniferous salites (Remédios sodic series), grading into aegirines in the differentiated aphyric phonolites. Cpx in the lamprophyres show disequilibrium textures. In the Quixaba flows, cpx are salites, enriched in Mg (especially in MEM). Amphiboles, remarkably, are common in tephriphonolites and phonolites and in basaltic trachyandesites, sometimes with disequilibrum zoning textures, and a conspicuous phase in lamprophyres. Dark micas are present as groundmass plates in MEM, OLM and PYM (olivine and pyroxene melanephelinites), with compositional variety (enriched in Ti, Ba, Sr) depending on the composition of the parent rock; BaO can be as high as 16-19%. Feldspars crystallize as calcic plagioclases, sanidines and anorthoclases, depending on the rock types, as phenocrysts and in groundmass, both in Quixaba and Remédios rocks; they are absent in nephelinites. Nephelines are found in Remédios sodic series types and Quixaba rocks. Haüyne and noseane are rarely observed in Remédios rocks.

  20. Terrestrial invasion of pomatiopsid gastropods in the heavy-snow region of the Japanese Archipelago

    PubMed Central

    2011-01-01

    Background Gastropod mollusks are one of the most successful animals that have diversified in the fully terrestrial habitat. They have evolved terrestrial taxa in more than nine lineages, most of which originated during the Paleozoic or Mesozoic. The rissooidean gastropod family Pomatiopsidae is one of the few groups that have evolved fully terrestrial taxa during the late Cenozoic. The pomatiopsine diversity is particularly high in the Japanese Archipelago and the terrestrial taxa occur only in this region. In this study, we conducted thorough samplings of Japanese pomatiopsid species and performed molecular phylogenetic analyses to explore the patterns of diversification and terrestrial invasion. Results Molecular phylogenetic analyses revealed that Japanese Pomatiopsinae derived from multiple colonization of the Eurasian Continent and that subsequent habitat shifts from aquatic to terrestrial life occurred at least twice within two Japanese endemic lineages. Each lineage comprises amphibious and terrestrial species, both of which are confined to the mountains in heavy-snow regions facing the Japan Sea. The estimated divergence time suggested that diversification of these terrestrial lineages started in the Late Miocene, when active orogenesis of the Japanese landmass and establishment of snowy conditions began. Conclusions The terrestrial invasion of Japanese Pomatiopsinae occurred at least twice beside the mountain streamlets of heavy-snow regions, which is considered the first case of this event in the area. Because snow coverage maintains stable temperatures and high humidity on the ground surface, heavy-snow conditions may have paved the way for these organisms from freshwater to land via mountain streamlets by preventing winter desiccation in mountain valleys. The fact that the terrestrialization of Pomatiopsidae occurred only in year-round wet environments, but not in seasonally dried regions, provides new insight into ancient molluscan terrestrialization

  1. Patterns of coral disease across the Hawaiian Archipelago: Relating disease to environment

    USGS Publications Warehouse

    Aeby, G.S.; Williams, G.J.; Franklin, E.C.; Kenyon, J.; Cox, E.F.; Coles, S.; Work, T.M.

    2011-01-01

    In Hawaii, coral reefs occur across a gradient of biological (host abundance), climatic (sea surface temperature anomalies) and anthropogenic conditions from the human-impacted reefs of the main Hawaiian Islands (MHI) to the pristine reefs of the northwestern Hawaiian Islands (NWHI). Coral disease surveys were conducted at 142 sites from across the Archipelago and disease patterns examined. Twelve diseases were recorded from three coral genera (Porites, Montipora, Acropora) with Porites having the highest prevalence. Porites growth anomalies (PorGAs) were significantly more prevalent within and indicative of reefs in the MHI and Porites trematodiasis (PorTrm) was significantly more prevalent within and indicative of reefs in the NWHI. Porites tissue loss syndrome (PorTLS) was also important in driving regional differences but that relationship was less clear. These results highlight the importance of understanding disease ecology when interpreting patterns of disease occurrence. PorTrm is caused by a parasitic flatworm that utilizes multiple hosts during its life cycle (fish, mollusk and coral). All three hosts must be present for the disease to occur and higher host abundance leads to higher disease prevalence. Thus, a high prevalence of PorTrm on Hawaiian reefs would be an indicator of a healthy coral reef ecosystem. In contrast, the high occurrence of PorGAs within the MHI suggests that PorGAs are related, directly or indirectly, to some environmental co-factor associated with increased human population sizes. Focusing on the three indicator diseases (PorGAs, PorTrm, PorTLS) we used statistical modeling to examine the underlying associations between disease prevalence and 14 different predictor variables (biotic and abiotic). All three diseases showed positive associations with host abundance and negative associations with thermal stress. The association with human population density differed among disease states with PorGAs showing a positive and PorTrm showing

  2. Investigation of a polynya in the Canadian Archipelago. 1. Introduction and oceanography

    SciTech Connect

    Topham, D.R.; Perkin, R.G.; Smith, S.D.; Anderson, R.J.; den Hartog, G.

    1983-03-30

    In certain parts of the Canadian Archipelago, small localized areas of water remain ice free throughout the winter, despite the extreme temperature differences between the atmosphere and the ocean surface. One such area, close to Dundas Island, has been studied in detail, both from the point of view of the atamospheric/oceanic heat exchange over the open water and its local geographic and oceanographic context. The paper describes the oceanography of the area and local weather and tidal flow conditions. A significant feature of the oceanographic records is a strong modulation of near-surface ocean temperature at tidal frequencies involving temperature differences as great as 0.2 /sup 0/C within a single tidal cycle. For the most part, the surface waters are 0.1/sup 0/ to 0.2 /sup 0/C above freezing. The presence of this relatively warm surface water is thought to be due to upward mixing occasioned by fast tidal flows across the shallow sill connecting Dundas and Devon islands. Historical records of water properties in the Sverdrup Basin lying to the north of the polynya area show temperatures substantially above freezing point at depths of 50 m and below. This readily accessible body of warm water is thought to be the source of the sensible heat required for the existence of the polynya. This is supported by existing current measurements which suggest a mean southerly transport in the channels leading into and out of the region of the polynya site. A tentative application of the atmospheric heat flux measurements to the whole Dundas Island--Bailey Hamilton Island area suggests that sufficient heat may be lost to affect significantly the water column further south in Crozier Strait and Wellington Channel. The limited information available shows the more southerly waters of these passages to be relatively well mixed and cooled relative to the water of the Sverdrup Basin, just to the north of the Dundas polynya area.

  3. An investigation of a polynya in the Canadian Archipelago: 1. Introduction and oceanography

    NASA Astrophysics Data System (ADS)

    Topham, D. R.; Perkin, R. G.; Smith, S. D.; Anderson, R. J.; Hartog, G. Den

    1983-03-01

    In certain parts of the Canadian Archipelago, small localized areas of water remain ice free throughout the winter, despite the extreme temperature differences between the atmosphere and the ocean surface. One such area, close to Dundas Island, has been studied in detail, both from the point of view of the atmospheric/oceanic heat exchange over the open water and its local geographic and oceanographic context. This paper describes the oceanography of the area and local weather and tidal flow conditions. A significant feature of the oceanographic records is a strong modulation of near-surface ocean temperature at tidal frequencies involving temperature differences as great as 0.2°C within a single tidal cycle. For the most part, the surface waters are 0.1° to 0.2°C above freezing. The presence of this relatively warm surface water is thought to be due to upward mixing occasioned by fast tidal flows across the shallow sill connecting Dundas and Devon islands. Historical records of water properties in the Sverdrup Basin lying to the north of the polynya area show temperatures substantially above freezing point at depths of 50 m and below. This readily accessible body of warm water is thought to be the source of the sensible heat required for the existence of the polynya. This is supported by existing current measurements which suggest a mean southerly transport in the channels leading into and out of the region of the polynya site. A tentative application of the atmospheric heat flux measurements to the whole Dundas Island-Bailey Hamilton Island area suggests that sufficient heat may be lost to affect significantly the water column further south in Crozier Strait and Wellington Channel. The limited information available shows the more southerly waters of these passages to be relatively well mixed and cooled relative to the water of the Sverdrup Basin, just to the north of the Dundas polynya area.

  4. Insular shifts in body size of rice frogs in the Zhoushan Archipelago, China.

    PubMed

    Wu, Zhengjun; Li, Yiming; Murray, Brad R

    2006-09-01

    1. Differences in body size between mainland and island populations have been reported for reptiles, birds and mammals. Despite widespread recognition of insular shifts in body size in these taxa, there have been no reports of such body size shifts in amphibians. 2. We provide the first evidence of an insular shift in body size for an amphibian species, the rice frog Rana limnocharis. We found significant increases in body size of rice frogs on most sampled islands in the Zhoushan archipelago when compared with neighbouring mainland China. 3. Large body size in rice frogs on islands was significantly related to increased population density, in both breeding and non-breeding seasons. Increases in rice frog density were significantly related to higher resource availability on islands. Increased resource availability on islands has led to higher carrying capacities, which has subsequently facilitated higher densities and individual growth rates, resulting in larger body size in rice frogs. We also suggest that large body size has evolved on islands, as larger individuals are competitively superior under conditions of harsh intraspecific competition at high densities. 4. Increases in body size in rice frogs were not related to several factors that have been implicated previously in insular shifts in body size in other taxa. We found no significant relationships between body size of rice frogs and prey size, number of larger or smaller frog species, island area or distance of islands from the mainland. 5. Our findings contribute to the formation of a broad, repeatable ecological generality for insular shifts in body size across a range of terrestrial vertebrate taxa, and provide support for recent theoretical work concerning the importance of resource availability for insular shifts in body size.

  5. Temporal variation in fish mercury concentrations within lakes from the western Aleutian Archipelago, Alaska

    USGS Publications Warehouse

    Kenney, Leah A.; Eagles-Smith, Collin A.; Ackerman, Joshua T.; von Hippel, Frank A.

    2014-01-01

    We assessed temporal variation in mercury (Hg) concentrations of threespine stickleback (Gasterosteus aculeatus) from Agattu Island, Aleutian Archipelago, Alaska. Total Hg concentrations in whole-bodied stickleback were measured at two-week intervals from two sites in each of two lakes from June 1 to August 10, 2011 during the time period when lakes were ice-free. Across all sites and sampling events, stickleback Hg concentrations ranged from 0.37–1.07 µg/g dry weight (dw), with a mean (± SE) of 0.55±0.01 µg/g dw. Mean fish Hg concentrations declined by 9% during the study period, from 0.57±0.01 µg/g dw in early June to 0.52±0.01 µg/g dw in mid-August. Mean fish Hg concentrations were 6% higher in Loon Lake (0.56±0.01 µg/g dw) than in Lake 696 (0.53±0.01 µg/g dw), and 4% higher in males (0.56±0.01 µg/g dw) than in females (0.54±0.01 µg/g dw). Loon Lake was distinguished from Lake 696 by the presence of piscivorous waterbirds during the breeding season. Mercury concentrations in stickleback from Agattu Island were higher than would be expected for an area without known point sources of Hg pollution, and high enough to be of concern to the health of piscivorous wildlife.

  6. Flank collapse triggered by intrusion: the Canarian and Cape Verde Archipelagoes

    NASA Astrophysics Data System (ADS)

    Elsworth, Derek; Day, Simon J.

    1999-12-01

    The potential to develop kilometer-scale instabilities on the flanks of intraplate volcanoes, typified by the Canary and Cape Verde Archipelagoes, is investigated. A primary triggering agent is forced injection of moderate-scale dikes, resulting in the concurrent development of mechanical and thermal fluid pressures along the basal décollement, and magmastatic pressures at the dike interface. These additive effects are shown capable of developing shallow-seated block instabilities for dike thicknesses of the order of 1 m, and horizontal lengths greater than about 1 km. For dikes that approach or penetrate the surface, and are greater in length than this threshold, the destabilizing influence of the magmastatic column is significant, and excess pore fluid pressures may not be necessary to initiate failure. The potentially destabilized block geometry changes from a flank-surface-parallel sliver for short dikes, to a deeper and less stable décollement as dike horizontal length builds and the effects of block lateral restraint diminish. For intrusions longer than about 1 km, the critical basal décollement dives below the water table and utilizes the complementary destabilizing influences of pore fluid pressures and magma "push" at the rear block-scarp. In addition to verifying the plausibility of suprahydrostatic pressures as capable of triggering failure on these volcanoes, timing of the onset of maximum instability may also be tracked. For events within the Cumbre Vieja (1949) and Fogo (1951, 1995) pre-effusive episodes, the observation of seismic activity within the first 1 week to 4 months is consistent with the predictions of thermal and mechanical pressurization.

  7. Cytogeography of Ixeris nakazonei (Asteraceae, Lactuceae) in the Ryukyu Archipelago of Japan and Taiwan.

    PubMed

    Denda, Tetsuo; Yokota, Masatsugu

    2004-02-01

    The cytogeographical structures of Ixeris nakazonei, a putative hybrid between I. debilis (6x) and I. repens (2x), were investigated in the Ryukyu Archipelago and Taiwan. In the Ryukyus, I. debilis occurs on Miyakojima Island of the southern Ryukyus and northward, while I. repens occurs on all islands except for Iriomotejima and Yonagunijima Islands. I. nakazonei, comprises six polyploid cytotypes, 3x, 4x, 5x, 6x, 7x and 8x, based on x=8. Four cytotypes from 3x to 6x occur in the central Ryukyus, while four cytotypes from 5x to 8x occur in the southern Ryukyus. The higher polyploids of I. nakazonei tend to be distributed in the more southerly area. Tetraploids of I. nakazonei always co-occur with I. debilis and I. repens, supporting the hybrid origin of this cytotype. Considering the chromosome number, octoploids, which predominate in the southern Ryukyus and Taiwan, may have derived directly from hybridization between I. debilis and I. repens. Odd-numbered polyploids of I. nakazonei, 3x, 5x and 7x, are relatively rare. Their chromosome numbers indicate that triploids and heptaploids are hybrids between the tetraploid of I. nakazonei and I. repens, and between the octoploid of I. nakazonei and I. debilis, respectively. Pentaploids of I. nakazonei in the central and southern Ryukyus are, respectively, hybrids between the tetraploid of I. nakazonei and I. debilis and between the octoploid of I. nakazonei and I. repens, indicating that pentaploids of I. nakazonei have at least two independent origins.

  8. Summertime sources of dimethyl sulfide in the Canadian Arctic Archipelago and Baffin Bay

    NASA Astrophysics Data System (ADS)

    Mungall, E. L.; Croft, B.; Lizotte, M.; Thomas, J. L.; Murphy, J. G.; Levasseur, M.; Martin, R. V.; Wentzell, J. J. B.; Liggio, J.; Abbatt, J. P. D.

    2015-12-01

    Dimethyl sulfide (DMS) plays a major role in the global sulfur cycle. In addition, its atmospheric oxidation products contribute to the formation and growth of atmospheric aerosol particles, thereby influencing cloud condensation nuclei (CCN) populations and thus cloud formation. The pristine summertime Arctic atmosphere is a CCN-limited regime, and is thus very susceptible to the influence of DMS. However, atmospheric DMS mixing ratios have only rarely been measured in the summertime Arctic. During July-August 2014, we conducted the first high time resolution (10 Hz) DMS mixing ratio measurements for the Eastern Canadian Archipelago and Baffin Bay as one component of the Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments (NETCARE). DMS mixing ratios ranged from below the detection limit of 4 to 1155 pptv (median 186 pptv). A set of transfer velocity parameterizations from the literature coupled with our atmospheric and coincident seawater DMS measurements yielded air-sea DMS flux estimates ranging from 0.02-12 μmol m-2 d-1, the first published for this region in summer. Airmass trajectory analysis using FLEXPART-WRF and chemical transport modeling using GEOS-Chem indicated that local sources (Lancaster Sound and Baffin Bay) were the dominant contributors to the DMS measured along the 21 day ship track, with episodic transport from the Hudson Bay System. After adjusting GEOS-Chem oceanic DMS values in the region to match measurements, GEOS-Chem reproduced the major features of the measured time series, but remained biased low overall (median 67 pptv). We investigated non-marine sources that might contribute to this bias, such as DMS emissions from lakes, biomass burning, melt ponds and coastal tundra. While the local marine sources of DMS dominated overall, our results suggest that non-local and possibly non-marine sources episodically contributed strongly to the observed summertime Arctic DMS mixing ratios.

  9. Diagenetic history of lower Pliocene rhodoliths of the Azores Archipelago (NE Atlantic): Application of cathodoluminescence techniques.

    PubMed

    Rebelo, A C; Meireles, R P; Barbin, V; Neto, A I; Melo, C; Ávila, S P

    2016-01-01

    The diagenetic history of calcareous fossils is required for their application as palaeoenvironmental indicators. In this study, cathodoluminescence-microscopy (CL microscopy) and back scatter electron image-energy dispersive X-ray spectroscopy (BSE-EDS microscopy) were applied to Pliocene rhodoliths from the Azores Archipelago (NE Atlantic) in order to gain additional insight regarding the trace element content distribution throughout the algae thalli, and to ascertain palaeoenvironmental interpretations. Two types of luminescence were obtained: (1) high and (2) low luminescence. Rhodoliths with high luminescence are related with high concentrations of Mn(2+) in seawater and low luminescence rhodoliths are related with low concentrations of Mn(2+) in seawater. When the rhodoliths were deposited at about 4.0-4.5 Ma, the shoreline configuration of Santa Maria Island was much different than today. The influence of volcanic activity due to the extrusion of lavas and associated products and/or the presence of active shallow-water hydrothermal vents, was reflected in the sea water chemistry, with penecontemporaneous palaeoshores of the island featuring a high sea water concentration of Mn(2+), which mirrored on the rhodolith Mn(2+) high concentration. By contrast, rhodoliths located about 2.8 and 2.9 km from the shore, in areas with low seawater Mn(2+) concentration, had low luminescence, reflecting the low Mn(2+) concentration in seawater. Rhodoliths chemical data and the geological history of the island proved to be congruent with the palaeogeographical reconstruction of Santa Maria Island at the time of the formation of the rhodoliths.

  10. Landfast ice thickness in the Canadian Arctic Archipelago from observations and models

    NASA Astrophysics Data System (ADS)

    Howell, Stephen E. L.; Laliberté, Frédéric; Kwok, Ron; Derksen, Chris; King, Joshua

    2016-07-01

    Observed and modelled landfast ice thickness variability and trends spanning more than 5 decades within the Canadian Arctic Archipelago (CAA) are summarized. The observed sites (Cambridge Bay, Resolute, Eureka and Alert) represent some of the Arctic's longest records of landfast ice thickness. Observed end-of-winter (maximum) trends of landfast ice thickness (1957-2014) were statistically significant at Cambridge Bay (-4.31 ± 1.4 cm decade-1), Eureka (-4.65 ± 1.7 cm decade-1) and Alert (-4.44 ± 1.6 cm -1) but not at Resolute. Over the 50+-year record, the ice thinned by ˜ 0.24-0.26 m at Cambridge Bay, Eureka and Alert with essentially negligible change at Resolute. Although statistically significant warming in spring and fall was present at all sites, only low correlations between temperature and maximum ice thickness were present; snow depth was found to be more strongly associated with the negative ice thickness trends. Comparison with multi-model simulations from Coupled Model Intercomparison project phase 5 (CMIP5), Ocean Reanalysis Intercomparison (ORA-IP) and Pan-Arctic Ice-Ocean Modeling and Assimilation System (PIOMAS) show that although a subset of current generation models have a "reasonable" climatological representation of landfast ice thickness and distribution within the CAA, trends are unrealistic and far exceed observations by up to 2 orders of magnitude. ORA-IP models were found to have positive correlations between temperature and ice thickness over the CAA, a feature that is inconsistent with both observations and coupled models from CMIP5.

  11. Terrestrial invasion of pomatiopsid gastropods in the heavy-snow region of the Japanese Archipelago.

    PubMed

    Kameda, Yuichi; Kato, Makoto

    2011-05-05

    Gastropod mollusks are one of the most successful animals that have diversified in the fully terrestrial habitat. They have evolved terrestrial taxa in more than nine lineages, most of which originated during the Paleozoic or Mesozoic. The rissooidean gastropod family Pomatiopsidae is one of the few groups that have evolved fully terrestrial taxa during the late Cenozoic. The pomatiopsine diversity is particularly high in the Japanese Archipelago and the terrestrial taxa occur only in this region. In this study, we conducted thorough samplings of Japanese pomatiopsid species and performed molecular phylogenetic analyses to explore the patterns of diversification and terrestrial invasion. Molecular phylogenetic analyses revealed that Japanese Pomatiopsinae derived from multiple colonization of the Eurasian Continent and that subsequent habitat shifts from aquatic to terrestrial life occurred at least twice within two Japanese endemic lineages. Each lineage comprises amphibious and terrestrial species, both of which are confined to the mountains in heavy-snow regions facing the Japan Sea. The estimated divergence time suggested that diversification of these terrestrial lineages started in the Late Miocene, when active orogenesis of the Japanese landmass and establishment of snowy conditions began. The terrestrial invasion of Japanese Pomatiopsinae occurred at least twice beside the mountain streamlets of heavy-snow regions, which is considered the first case of this event in the area. Because snow coverage maintains stable temperatures and high humidity on the ground surface, heavy-snow conditions may have paved the way for these organisms from freshwater to land via mountain streamlets by preventing winter desiccation in mountain valleys. The fact that the terrestrialization of Pomatiopsidae occurred only in year-round wet environments, but not in seasonally dried regions, provides new insight into ancient molluscan terrestrialization.

  12. Refugia of Potentilla matsumurae (Rosaceae) located at high mountains in the Japanese archipelago.

    PubMed

    Ikeda, Hajime; Senni, Kei; Fujii, Noriyuki; Setoguchi, Hiroaki

    2006-10-01

    Molecular phylogeographic studies have revealed the genetic patterns and glacial-interglacial history of many plant and animal species. To infer the Quaternary history of alpine plants in the Japanese archipelago, which is poorly known, we investigated 203 individuals of Potentilla matsumurae and its varieties from 22 populations. We found 11 haplotypes based on approximately 1400 bp of two intergenetic spacers in chloroplast DNA (trnT-L and rpl20-rps20). The distribution of these haplotypes was geographically structured, which was supported by haplotype composition, principal component analysis, and unweighted pair group method with arithmetic mean (UPGMA), and N(ST) (0.71) was significantly greater than G(ST) (0.68). In addition to the positive correlation between genetic and geographic distance (Mantel test, r = 0.497, P < 0.001), an abrupt genetic change was detected between mountains in central Honshu and the Tohoku region. This genetic boundary was further supported by analysis of molecular variance (AMOVA), and high variation (54.0%) was explained by differences on either side of this boundary. Moreover, haplotypes in central Honshu were thought to have diverged, based on an outgroup comparison. These results suggest that mountains in central Honshu served as refugia during the Quaternary climatic oscillation, although the results could not reveal the history of most mountains in the Tohoku region and Hokkaido. Nevertheless, following floristic studies, our results indicate that alpine plants in Japan experienced a history different from that in Europe; i.e. they retreated into refugia during warm periods to avoid forest development, rather than glaciers.

  13. RESEARCH PAPERS : Evidence for the Blake event in volcanic rocks from Lipari (Aeolian Archipelago)

    NASA Astrophysics Data System (ADS)

    Zanella, Elena; Laurenzi, Marinella A.

    1998-01-01

    Palaeomagnetic and geochronological measurements have been carried out on the late Pleistocene basaltic-andesitic unit of Monte Chirica-Costa Rasa, on the island of Lipari (Aeolian Archipelago). The lava flow sequence is about 10 m thick and has been sampled in detail. Magnetic properties are rather uniform; Curie temperatures of 540° to 580°C, and the saturation IRM reached at applied values of 0.1 T point to titanomagnetite as the main magnetization carrier. Thermal and AF demagnetization have shown the presence of secondary magnetization components. These were removed mostly at 450°-500°C or 20-30 mT, indicating a highly stable ChRM with directions from transitional to reverse. Where a ChRM could not be isolated by application of the demagnetization techniques, the converging remagnetization circles method gave a mean ChRM value fully comparable with that obtained from other methods. 40Ar/39Ar determinations were performed on two lava flows, in the lower and upper parts of the sequence. The former shows a transitional ChRM direction and a whole-rock age of 157+/-12 ka, the latter a reverse direction, a whole-rock age of 143+/-17 ka and a ground-mass age of 128+/-23 ka. The radiometric data and the reconstructed stratigraphy, which indicate ages of 150+/-10 ka and 104+/-3.5 ka, respectively, for the volcanic units at the bottom and top of the Monte Chirica-Costa Rasa unit, suggest that the reverse directions recorded in Lipari are related to the Blake event.

  14. Population Abundance of the Endangered Galapagos Sea Lion Zalophus wollebaeki in the Southeastern Galapagos Archipelago.

    PubMed

    Riofrío-Lazo, Marjorie; Arreguín-Sánchez, Francisco; Páez-Rosas, Diego

    2017-01-01

    There is great concern regarding the population status of the endangered Galapagos sea lion (GSL) because it has drastically decreased over the last 30 years. We determined the population size and growth trend of the GSL in the Galapagos southeastern region (SER) at three population levels based on the available census data: 1) SER (2011-2015), including 13 rookeries on the four islands San Cristóbal (SC), Española, Floreana, and Santa Fe, comprising 58% of the archipelago's population; 2) SC (2011-2015), including five rookeries, comprising 52% of the SER population; and 3) El Malecón (2005-2015), the largest rookery on SC and in the SER (43% of the population on SC and 22% in the SER). We also analyzed the influence of environmental variability on pup abundance in these rookeries. The current GSL population size in the SER, after applying correction factors to the counts, is estimated at approximately 2300-4100 individuals and has declined at an average annual rate (ʎ) of 8.7% over the last five years. A similar trend was determined for SC but at ʎ = 1.4% during the same period. For El Malecón, a count-based population viability analysis using a diffusion approximation approach showed that the population increased from 2005 to 2015 at ʎ = 2%. The interannual variability in pup abundance was associated with anomalies in sea surface temperature linked to oceanographic-atmospheric events, which impact the abundance and availability of prey, and ultimately may determine the population's reproductive success. Since rookeries in the SER had different population trends, management actions should be implemented based on their specific conditions, giving priority to rookeries such as El Malecón, which, despite showing a slightly increasing population trend, still faces a high risk of extinction due to anthropogenic disturbances and environmental variability that may affect its growth and survival.

  15. Macrophytobenthic flora of the Abrolhos Archipelago and the Sebastião Gomes Reef, Brazil

    NASA Astrophysics Data System (ADS)

    Torrano-Silva, Beatriz N.; Oliveira, Eurico C.

    2013-11-01

    The Abrolhos Bank, located on the coast of Bahia, Brazil, harbors the largest coral reef system in the South Atlantic. This area has attracted the attention of biologists because of its peculiar mushroom-shaped structures, locally known as "chapeirões", and endemic species of corals and other organisms. The macrophytobenthos compartment plays an important ecological role in the functioning of the bank, and some reports on the presence of seaweeds and seagrasses have been published; however, the data are fragmentary, and a more detailed survey of the macrophytobenthos compartment is lacking. Here we consolidate the information available and add new data obtained from two expeditions focused on seaweed and seagrass diversity from two sectors of the bank: the islands of the Abrolhos archipelago (AA) and the Sebastião Gomes Reef (SG). These sites were selected for their contrasting characteristics. Specifically, SG (15 km off the mouth of the Caravelas River) is subjected to a broader range of anthropogenic impacts and to input of terrigenous sediments, while the AA (54 km offshore) is surrounded by calcareous biogenic sediments, has clearer water and is less affected by human activities. Macrophytobenthic species richness on both reference areas is larger than previously thought. Considering previous records, there are 164 species of macrophytes in AA and 111 species in SG, of which 59 and 74 species are first records for each respective location. The higher species richness at the AA may result from a higher habitat complexity and lower turbidity, but a potential negative effect of enhanced human impacts at SG cannot be ruled out. Considering that macroalgae are relevant components of the benthic community, as producers and structurer organisms, the data presented herein provide a reliable baseline for future environmental studies, and thus may contribute to improve management policies within the unique ecosystem of Abrolhos.

  16. Indirect food web interactions: Sea otters and kelp forest fishes in the Aleutian archipelago

    USGS Publications Warehouse

    Reisewitz, S.E.; Estes, J.A.; Simenstad, C.A.

    2006-01-01

    Although trophic cascades - the effect of apex predators on progressively lower trophic level species through top-down forcing - have been demonstrated in diverse ecosystems, the broader potential influences of trophic cascades on other species and ecosystem processes are not well studied. We used the overexploitation, recovery and subsequent collapse of sea otter (Enhydra lutris) populations in the Aleutian archipelago to explore if and how the abundance and diet of kelp forest fishes are influenced by a trophic cascade linking sea otters with sea urchins and fleshy macroalgae. We measured the abundance of sea urchins (biomass density), kelp (numerical density) and fish (Catch per unit effort) at four islands in the mid-1980s (when otters were abundant at two of the islands and rare at the two others) and in 2000 (after otters had become rare at all four islands). Our fish studies focused on rock greenling (Hexagrammos lagocephalus), the numerically dominant species in this region. In the mid-1980s, the two islands with high-density otter populations supported dense kelp forests, relatively few urchins, and abundant rock greenling whereas the opposite pattern (abundant urchins, sparse kelp forests, and relatively few rock greenling) occurred at islands where otters were rare. In the 2000, the abundances of urchins, kelp and greenling were grossly unchanged at islands where otters were initially rare but had shifted to the characteristic pattern of otter-free systems at islands where otters were initially abundant. Significant changes in greenling diet occurred between the mid-1980s and the 2000 although the reasons for these changes were difficult to assess because of strong island-specific effects. Whereas urchin-dominated communities supported more diverse fish assemblages than kelp-dominated communities, this was not a simple effect of the otter-induced trophic cascade because all islands supported more diverse fish assemblages in 2000 than in the mid-1980s

  17. Stress response of two coral species in the Kavaratti atoll of the Lakshadweep Archipelago, India

    NASA Astrophysics Data System (ADS)

    Harithsa, Shashank; Raghukumar, Chandralata; Dalal, S. G.

    2005-11-01

    Frequent occurrences of coral bleaching and the ensuing damage to coral reefs have generated interest in documenting stress responses that precede bleaching. The objective of this study was to assess and compare physiological changes in healthy, semi-bleached and totally bleached colonies of two coral species, Porites lutea and Acropora formosa, during a natural bleaching event in the Lakshadweep Archipelago in the Arabian Sea to determine the traits that will be useful in the diagnosis of coral health. In April 2002, three “health conditions” were observed as “appearing healthy,” “semi-bleached” and “bleached” specimens for two dominant and co-occurring coral species in these islands. Changes in the pigment composition, zooxanthellae density (ZD), mitotic index (MI) of zooxanthellae, RNA/DNA ratios and protein profile in the two coral species showing different levels of bleaching in the field were compared to address the hypothesis of no difference in health condition between species and bleaching status. The loss in chlorophyll (chl) a, chl c and ZD in the transitional stage of semi-bleaching in the branched coral A. formosa was 80, 75 and 80%, respectively. The losses were much less in the massive coral P. lutea, being 20, 50 and 25%, respectively. The decrease in zooxanthellar density and chl a was accompanied by an increased MI of zooxanthellae and RNA/DNA ratios in both the species. There was an increase in accumulation of lipofuscin granules in partially bleached P. lutea tissue, which is an indication of cellular senescence. Multivariate statistical analyses showed that colonies of P. lutea ranked in different health conditions differed significantly in chl a, chl c, ZD, RNA/DNA ratios, and protein concentrations, whereas in A. formosa chl a, chl c, chl a/ c, phaeopigments and MI contributed to the variance between health conditions.

  18. Prediction and verification of possible reef-fish spawning aggregation sites in Los Roques Archipelago National Park, Venezuela.

    PubMed

    Boomhower, J; Romero, M; Posada, J; Kobara, S; Heyman, W

    2010-09-01

    This study attempts to predict and verify possible spawning aggregation sites and times in the Los Roques Archipelago National Park, Venezuela, based on physical reef characteristics and the knowledge of experienced local fishermen. Three possible aggregation sites were selected for monitoring based on satellite images, low-cost bathymetric mapping and interviews with experienced local fishermen. Abundances and sizes of 18 species that are known to form reproductive aggregations were monitored at these sites using underwater visual census for 7 days after each full moon from February to August, 2007. While spawning events were not observed, possible indirect evidence of spawning aggregations was found for Lutjanus analis at Cayo Sal and Boca de Sebastopol, Lutjanus apodus at Cayo Sal, Lutjanus cyanopterus at Cayo Sal and Piedra La Guasa and Epinephelus guttatus at Bajo California and Cayo de Agua. Additionally, indirect evidence was identified for the past existence of a spawning aggregation of Epinephelus striatus in the northern part of the archipelago, which may have been eliminated by overfishing c.15 years ago. Bathymetric mapping showed that the shelf edge at sites monitored in this study was shallower than at spawning aggregation sites in other parts of the Caribbean, and that sites were not proximal to deep water. While this study does not prove the existence or locations of spawning aggregations of reef fishes in the archipelago, it does add insight to a growing understanding of generalities in the relationship between seafloor characteristics and the locations of transient reef-fish spawning aggregations in the Caribbean. © 2010 The Authors. Journal compilation © 2010 The Fisheries Society of the British Isles.

  19. Colonization and diversification of aquatic insects on three Macaronesian archipelagos using 59 nuclear loci derived from a draft genome.

    PubMed

    Rutschmann, Sereina; Detering, Harald; Simon, Sabrina; Funk, David H; Gattolliat, Jean-Luc; Hughes, Samantha J; Raposeiro, Pedro M; DeSalle, Rob; Sartori, Michel; Monaghan, Michael T

    2017-02-01

    The study of processes driving diversification requires a fully sampled and well resolved phylogeny, although a lack of phylogenetic markers remains a limitation for many non-model groups. Multilocus approaches to the study of recent diversification provide a powerful means to study the evolutionary process, but their application remains restricted because multiple unlinked loci with suitable variation for phylogenetic or coalescent analysis are not available for most non-model taxa. Here we identify novel, putative single-copy nuclear DNA (nDNA) phylogenetic markers to study the colonization and diversification of an aquatic insect species complex, Cloeon dipterum L. 1761 (Ephemeroptera: Baetidae), in Macaronesia. Whole-genome sequencing data from one member of the species complex were used to identify 59 nDNA loci (32,213 base pairs), followed by Sanger sequencing of 29 individuals sampled from 13 islands of three Macaronesian archipelagos. Multispecies coalescent analyses established six putative species. Three island species formed a monophyletic clade, with one species occurring on the Azores, Europe and North America. Ancestral state reconstruction indicated at least two colonization events from the mainland (to the Canaries, respectively Azores) and one within the archipelago (between Madeira and the Canaries). Random subsets of the 59 loci showed a positive linear relationship between number of loci and node support. In contrast, node support in the multispecies coalescent tree was negatively correlated with mean number of phylogenetically informative sites per locus, suggesting a complex relationship between tree resolution and marker variability. Our approach highlights the value of combining genomics, coalescent-based phylogeography, species delimitation, and phylogenetic reconstruction to resolve recent diversification events in an archipelago species complex.

  20. Applying Fishers' Ecological Knowledge to Construct Past and Future Lobster Stocks in the Juan Fernández Archipelago, Chile

    PubMed Central

    Eddy, Tyler D.; Gardner, Jonathan P. A.; Pérez-Matus, Alejandro

    2010-01-01

    Over-exploited fisheries are a common feature of the modern world and a range of solutions including area closures (marine reserves; MRs), effort reduction, gear changes, ecosystem-based management, incentives and co-management have been suggested as techniques to rebuild over-fished populations. Historic accounts of lobster (Jasus frontalis) on the Chilean Juan Fernández Archipelago indicate a high abundance at all depths (intertidal to approximately 165 m), but presently lobsters are found almost exclusively in deeper regions of their natural distribution. Fishers' ecological knowledge (FEK) tells a story of serial depletion in lobster abundance at fishing grounds located closest to the fishing port with an associated decline in catch per unit effort (CPUE) throughout recent history. We have re-constructed baselines of lobster biomass throughout human history on the archipelago using historic data, the fishery catch record and FEK to permit examination of the potential effects of MRs, effort reduction and co-management (stewardship of catch) to restore stocks. We employed a bioeconomic model using FEK, fishery catch and effort data, underwater survey information, predicted population growth and response to MR protection (no-take) to explore different management strategies and their trade-offs to restore stocks and improve catches. Our findings indicate that increased stewardship of catch coupled with 30% area closure (MR) provides the best option to reconstruct historic baselines. Based on model predictions, continued exploitation under the current management scheme is highly influenced by annual fluctuations and unsustainable. We propose a community-based co-management program to implement a MR in order to rebuild the lobster population while also providing conservation protection for marine species endemic to the Archipelago. PMID:21079761

  1. The response of benthic meiofauna to hydrothermal emissions in the Pontine Archipelago, Tyrrhenian Sea (central Mediterranean Basin)

    NASA Astrophysics Data System (ADS)

    Di Bella, Letizia; Ingrassia, Michela; Frezza, Virgilio; Chiocci, Francesco Latino; Martorelli, Eleonora

    2016-12-01

    Recent investigations highlighted the occurrence of a giant depression related to hydrothermal activity off the Pontine Archipelago (central Mediterranean Sea, Italy). The new record of a giant seeping depression (Zannone Giant Pockmark, ZGP) in shallow-water provides the opportunity to study fluid vent impact on meiobenthic communities. The micropaleontological analyses on living (Rose Bengal stained) and dead assemblages recorded inside and outside the Zannone Giant Pockmark, allow to highlight changes in the structure and composition of the foraminiferal community that suggest variations of fluid emissions in different sectors of the study area. Inside the ZGP, under the direct influence of venting activity, a very peculiar living foraminiferal assemblage is found. It consists of agglutinated species (Spiculosiphon oceana, Jaculella acuta, Deuterammina rotaliformis) never found or very rare in the Mediterranean Sea. On the contrary dead assemblage testifies the changes on foraminiferal assemblages under carbonate dissolution process. Outside the pockmark in the nearby area of ZGP, the integrated meiofaunal and geochemical data suggest a transitional condition between vent influenced sedimentation and the typical carbonate sedimentation recorded in the rest of the Pontine Archipelago. In particular a possible spread of the venting activity in the northern and southern sectors of the study area, towards the edge of the Zannone insular shelf, is inferred. The impact of fluid emissions on foraminiferal assemblages can be summarized in the following observations: reduced biodiversity, increase of agglutinated species with predominant siliceous component in the test structure, limited distribution of living specimens inside the sediment, disappearance of porcelaneous taxa and presence of carbonate loss tests. As the result, the venting activity is likely to be the main environmental driver on the meiofaunal distribution. We also report, at the emission sites in the

  2. Phylogenetic study of sponge associated bacteria from the Lakshadweep archipelago and the antimicrobial activities of their secondary metabolites.

    PubMed

    Gopi, M; Ajith Kumar, T T; Balagurunathan, R; Vinoth, R; Dhaneesh, K V; Rajasekaran, R; Balasubramanian, T

    2012-02-01

    Marine ecosystem of the Lakshadweep archipelago is unique and known to have a very high degree of biodiversity with a number of endemic flora and fauna. The present study focuses to isolate the endosymbiotic microorganism from sponges and its effectiveness against marine ornamental fish pathogens. The sponges were collected from Agatti island of Lakshadweep archipelago and identified as Clathria procera, Sigmadocia fibulata and Dysidea granulosa. In which, 15 different types of bacteria were isolated and screened against marine ornamental fish pathogens (A. hydrophila, Vibrio alginolyticus, V. harveyii, V. parahaemolyticus and Pseudomonas fluorescens). The strain S25 was found as potential bacteria based on their antimicrobial activity against the fish pathogens. Molecular identification of the potential strain (S25) of the 16S rRNA gene showed 99% identity with Acinetobacter sp. The sequenced 16 s rRNA gene with 1,081 bp in length was submitted in NCBI Genbank and Accession was obtained (GenBank Accession number HM004071). The strain exhibited high similarity (99%) with the 16S rRNA gene of Acinetobacter calcoaceticus from GenBank database. Crude extract obtained with acetone and ethyl acetate from extracellular products of S25 showed significant antimicrobial activity by disc diffusion assay using 1,500 μg/ml of crude extract. Extracellular metobolite of A. calcoaceticus was extracted by shake flask method and the crude extract was partially purified by thin layer chromatography. Partially purified crude extract showed significant inhibition zone of antimicrobial activity (A. hydrophila, V. alginolyticus, V. parahaemolyticus) and less similar activity against V. harveyii and P. fluorescens. This is the first report on A. calcoaceticus isolated from sponges of Lakshadweep archipelago and the studies are underway to characterize and purify the antimicrobial compounds of the potential bacteria.

  3. Diversity and Distribution of Symbiodinium Associated with Seven Common Coral Species in the Chagos Archipelago, Central Indian Ocean

    PubMed Central

    Obura, David; Sheppard, Charles R. C.; Visram, Shakil; Chen, Chaolun Allen

    2012-01-01

    The Chagos Archipelago designated as a no-take marine protected area in 2010, lying about 500 km south of the Maldives in the Indian Ocean, has a high conservation priority, particularly because of its fast recovery from the ocean-wide massive coral mortality following the 1998 coral bleaching event. The aims of this study were to examine Symbiodinium diversity and distribution associated with scleractinian corals in five atolls of the Chagos Archipelago, spread over 10,000 km 2. Symbiodinium clade diversity in 262 samples of seven common coral species, Acropora muricata, Isopora palifera, Pocillopora damicornis, P. verrucosa, P. eydouxi, Seriatopora hystrix, and Stylophora pistillata were determined using PCR-SSCP of the ribosomal internal transcribed spacer 1 (ITS1), PCR-DDGE of ITS2, and phylogenetic analyses. The results indicated that Symbiodinium in clade C were the dominant symbiont group in the seven coral species. Our analysis revealed types of Symbiodinium clade C specific to coral species. Types C1 and C3 (with C3z and C3i variants) were dominant in Acroporidae and C1 and C1c were the dominant types in Pocilloporidae. We also found 2 novel ITS2 types in S. hystrix and 1 novel ITS2 type of Symbiodinium in A. muricata. Some colonies of A. muricata and I. palifera were also associated with Symbiodinium A1. These results suggest that corals in the Chagos Archipelago host different assemblages of Symbiodinium types then their conspecifics from other locations in the Indian Ocean; and that future research will show whether these patterns in Symbiodinium genotypes may be due to local adaptation to specific conditions in the Chagos. PMID:22567113

  4. Applying Fishers' ecological knowledge to construct past and future lobster stocks in the Juan Fernández Archipelago, Chile.

    PubMed

    Eddy, Tyler D; Gardner, Jonathan P A; Pérez-Matus, Alejandro

    2010-11-05

    Over-exploited fisheries are a common feature of the modern world and a range of solutions including area closures (marine reserves; MRs), effort reduction, gear changes, ecosystem-based management, incentives and co-management have been suggested as techniques to rebuild over-fished populations. Historic accounts of lobster (Jasus frontalis) on the Chilean Juan Fernández Archipelago indicate a high abundance at all depths (intertidal to approximately 165 m), but presently lobsters are found almost exclusively in deeper regions of their natural distribution. Fishers' ecological knowledge (FEK) tells a story of serial depletion in lobster abundance at fishing grounds located closest to the fishing port with an associated decline in catch per unit effort (CPUE) throughout recent history. We have re-constructed baselines of lobster biomass throughout human history on the archipelago using historic data, the fishery catch record and FEK to permit examination of the potential effects of MRs, effort reduction and co-management (stewardship of catch) to restore stocks. We employed a bioeconomic model using FEK, fishery catch and effort data, underwater survey information, predicted population growth and response to MR protection (no-take) to explore different management strategies and their trade-offs to restore stocks and improve catches. Our findings indicate that increased stewardship of catch coupled with 30% area closure (MR) provides the best option to reconstruct historic baselines. Based on model predictions, continued exploitation under the current management scheme is highly influenced by annual fluctuations and unsustainable. We propose a community-based co-management program to implement a MR in order to rebuild the lobster population while also providing conservation protection for marine species endemic to the Archipelago.

  5. Comparative phylogeography of tenebrionid beetles in the Aegean archipelago: the effect of dispersal ability and habitat preference.

    PubMed

    Papadopoulou, Anna; Anastasiou, Ioannis; Keskin, Bekir; Vogler, Alfried P

    2009-06-01

    Comparative phylogeographical studies in island archipelagos can reveal lineage-specific differential responses to the geological and climatic history. We analysed patterns of genetic diversity in six codistributed lineages of darkling beetles (Tenebrionidae) in the central Aegean archipelago which differ in wing development and habitat preferences. A total of 600 specimens from 30 islands and eight adjacent mainland regions were sequenced for mitochondrial cytochrome oxidase I and nuclear Muscular protein 20. Individual gene genealogies were assessed for the presence of groups that obey an independent coalescent process using a mixed Yule coalescent model. The six focal taxa differed greatly in the number of coalescent groups and depth of lineage subdivision, which was closely mirrored by the degree of geographical structuring. The most severe subdivision at both mitochondrial DNA and nuclear DNA level was found in flightless lineages associated with presumed stable compact-soil habitats (phrygana, maquis), in contrast to sand-obligate lineages inhabiting ephemeral coastal areas that displayed greater homogeneity across the archipelago. A winged lineage, although associated with stable habitats, showed no significant phylogenetic or geographical structuring. Patterns of nucleotide diversity and local genetic differentiation, as measured using PhiST and hierarchical AMOVA, were consistent with high levels of ongoing gene flow in the winged taxon; frequent local extinction and island recolonisation for flightless sand-obligate taxa; and very low gene flow and geographical structure largely defined by the palaeogeographical history of the region in flightless compact-soil taxa. These results show that differences in dispersal rate, mediated by habitat persistence, greatly influence the levels of phylogeographical subdivision in lineages that are otherwise subjected to the same geological events and palaeoclimatic changes.

  6. A Complex Evolutionary History in a Remote Archipelago: Phylogeography and Morphometrics of the Hawaiian Endemic Ligia Isopods

    PubMed Central

    Santamaria, Carlos A.; Mateos, Mariana; Taiti, Stefano; DeWitt, Thomas J.; Hurtado, Luis A.

    2013-01-01

    Compared to the striking diversification and levels of endemism observed in many terrestrial groups within the Hawaiian Archipelago, marine invertebrates exhibit remarkably lower rates of endemism and diversification. Supralittoral invertebrates restricted to specific coastal patchy habitats, however, have the potential for high levels of allopatric diversification. This is the case of Ligia isopods endemic to the Hawaiian Archipelago, which most likely arose from a rocky supralittoral ancestor that colonized the archipelago via rafting, and diversified into rocky supralittoral and inland lineages. A previous study on populations of this isopod from Oʻahu and Kauaʻi revealed high levels of allopatric differentiation, and suggested inter-island historical dispersal events have been rare. To gain a better understanding on the diversity and evolution of this group, we expanded prior phylogeographic work by incorporating populations from unsampled main Hawaiian Islands (Maui, Molokaʻi, Lanaʻi, and Hawaiʻi), increasing the number of gene markers (four mitochondrial and two nuclear genes), and conducting Maximum likelihood and Bayesian phylogenetic analyses. Our study revealed new lineages and expanded the distribution range of several lineages. The phylogeographic patterns of Ligia in the study area are complex, with Hawaiʻi, Oʻahu, and the Maui-Nui islands sharing major lineages, implying multiple inter-island historical dispersal events. In contrast, the oldest and most geographically distant of the major islands (Kauaʻi) shares no lineages with the other islands. Our results did not support the monophyly of all the supralittoral lineages (currently grouped into L. hawaiensis), or the monophyly of the terrestrial lineages (currently grouped into L. perkinsi), implying more than one evolutionary transition between coastal and inland forms. Geometric-morphometric analyses of three supralittoral clades revealed significant body shape differences among them. A

  7. On three endemic species of the linyphiid spider genus Canariphantes Wunderlich, 1992 (Araneae, Linyphiidae) from the Azores archipelago.

    PubMed

    Crespo, Luís Carlos; Bosmans, Robert; Cardoso, Pedro; Borges, Paulo A V

    2014-07-28

    We describe Canariphantes junipericola n. sp. and C. relictus n. sp., new single-island endemic linyphiid spiders from the islands of Flores and Santa Maria (Azorean archipelago, Macaronesia), respectively. The female of the first species was incorrectly assigned to Canariphantes acoreensis (Wunderlich, 1992), a species occurring in four islands in the Central Group of Azores (Faial, Pico, São Jorge and Terceira). The latter species is transferred to Canariphantes, its male redescribed and the female genitalia described for the first time. We discuss the systematic affinities of these new species and comment on their conservation status. 

  8. Assessment of island beach erosion due to sea level rise: the case of the Aegean archipelago (Eastern Mediterranean)

    NASA Astrophysics Data System (ADS)

    Monioudi, Isavela N.; Velegrakis, Adonis F.; Chatzipavlis, Antonis E.; Rigos, Anastasios; Karambas, Theophanis; Vousdoukas, Michalis I.; Hasiotis, Thomas; Koukourouvli, Nikoletta; Peduzzi, Pascal; Manoutsoglou, Eva; Poulos, Serafim E.; Collins, Michael B.

    2017-03-01

    The present contribution constitutes the first comprehensive attempt to (a) record the spatial characteristics of the beaches of the Aegean archipelago (Greece), a critical resource for both the local and national economy, and (b) provide a rapid assessment of the impacts of the long-term and episodic sea level rise (SLR) under different scenarios. Spatial information and other attributes (e.g., presence of coastal protection works and backshore development) of the beaches of the 58 largest islands of the archipelago were obtained on the basis of remote-sensed images available on the web. Ranges of SLR-induced beach retreats under different morphological, sedimentological and hydrodynamic forcing, and SLR scenarios were estimated using suitable ensembles of cross-shore (1-D) morphodynamic models. These ranges, combined with empirically derived estimations of wave run-up induced flooding, were then compared with the recorded maximum beach widths to provide ranges of retreat/erosion and flooding at the archipelago scale. The spatial information shows that the Aegean pocket beaches may be particularly vulnerable to mean sea level rise (MSLR) and episodic SLRs due to (i) their narrow widths (about 59 % of the beaches have maximum widths < 20 m), (ii) their limited terrestrial sediment supply, (iii) the substantial coastal development and (iv) the limited existing coastal protection. Modeling results indeed project severe impacts under mean and episodic SLRs, which by 2100 could be devastating. For example, under MSLR of 0.5 m - representative concentration pathway (RCP) 4.5 of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate change (IPCC) - a storm-induced sea level rise of 0.6 m is projected to result in a complete erosion of between 31 and 88 % of all beaches (29-87 % of beaches are currently fronting coastal infrastructure and assets), at least temporarily. Our results suggest a very considerable risk which will require significant

  9. An assessment of the record in compositional variations from mantle source to magmatism at East Island, Crozet archipelago

    NASA Astrophysics Data System (ADS)

    Meyzen, C. M.; Marzoli, A.; Bellieni, G.

    2013-12-01

    The Crozet archipelago, located midway between Madagascar and Antarctica, constitutes the emerged part of the easternmost bank of the Crozet plateau, which lies upon upper Cretaceous oceanic seafloor derived from the Southeast Indian Ridge. It forms an elongated chain of five islands and islets, divided into two groups: an older eastern island group (< 9 Ma) composed by large-scale volcanic landmasses (i.e. East and Possession islands) and a younger western one (< 5.5 Ma) with pint-sized islands. The whole region exhibits some of the most typical gravimetric, seismic and bathymetric characteristics associated with upwelling hotter than average mantle including: a geoid high, a topographic swell, a deep low-velocity zone (up to 2350 km), an anomalous heat flow and a thickened crust (10-16.5 km). Most of these features are exacerbated by the near stationary absolute motion of the Antarctic plate. However, since thirty years, the chemical composition of Crozet archipelago magmas has beneficiated from little interest compared to that of other Earth's hotspots. Because of the occurrence of both a thick and old lithosphere and of a near stagnant absolute plate motion, new data from the Crozet archipelago magmatic record will provide new critical perspective on oceanic island building processes. The data presented here are based on a basaltic suite of ~ 25 samples collected by a 'Terres Australes et Antarctiques Francaises' expedition in 1969 from the northern part of East Island. Our alkali basalts from the Crozet archipelago are distinct from other oceanic within-plate magmatic rocks in showing ubiquitous large depletions in LILE with respect to other incompatible elements, although these rocks constitute one of the most incompatible-element-enriched suites among Earth's oceanic island basalts (OIB). The similarity of their trace element ratios and parallelism of their rare earth element patterns indicate: (1) a mantle source homogeneity over at least 1 Ma; (2) an

  10. Development of microsatellite markers in Robinsonia (Asteraceae) an endemic genus of the Juan Fernández Archipelago, Chile.

    PubMed

    Takayama, Koji; López Sepúlveda, Patricio; Kohl, Gudrun; Novak, Johannes; Stuessy, Tod F

    2013-03-01

    Ten microsatellite markers were developed for Robinsonia (Asteraceae), a genus endemic to the Juan Fernández Archipelago, Chile. Polymorphisms of these markers were tested using one population each of R. evenia, R. gayana, and R. gracilis. The number of alleles for these markers ranged from 2 to 17 per locus, and expected heterozygosity ranged from 0 to 0.847 by population. A significant deviation from Hardy-Weinberg equilibrium was observed in zero to two markers in each population, and no significant linkage disequilibrium between markers was detected. The markers reported here would be useful for evolutionary studies and conservation strategies in Robinsonia.

  11. Structural trends in the Southern Cook and Austral archipelagoes (South Central Pacific) based on an analysis of Seasat data - Geodynamic implications

    NASA Astrophysics Data System (ADS)

    Diament, M.; Baudry, N.

    1987-10-01

    Filtered Seasat data for an area covering the Cook-Austral archipelagoes reveal the existence of two directions with azimuths of N 150 deg and N 95 deg. The first corresponds to a long linear topographic bump, and is suggested to confirm the existence of an ancient hot spot with a trace copolar to the Emperor chain. This result may explain both an important thermal rejuvenation noted in that area, and the very disturbed ages and morphologies of volcanic structures recorded in the Austral archipelago. The second direction is underlined by geoid signatures of fracture zone type which are interpreted as a possible consequence of recent intraplate deformation.

  12. The Madeira Archipelago As a Significant Source of Marine-Derived Actinomycete Diversity with Anticancer and Antimicrobial Potential.

    PubMed

    Prieto-Davó, Alejandra; Dias, Tiago; Gomes, Sofia E; Rodrigues, Sara; Parera-Valadez, Yessica; Borralho, Pedro M; Pereira, Florbela; Rodrigues, Cecilia M P; Santos-Sanches, Ilda; Gaudêncio, Susana P

    2016-01-01

    Marine-derived actinomycetes have demonstrated an ability to produce novel compounds with medically relevant biological activity. Studying the diversity and biogeographical patterns of marine actinomycetes offers an opportunity to identify genera that are under environmental pressures, which may drive adaptations that yield specific biosynthetic capabilities. The present study describes research efforts to explore regions of the Atlantic Ocean, specifically around the Madeira Archipelago, where knowledge of the indigenous actinomycete diversity is scarce. A total of 400 actinomycetes were isolated, sequenced, and screened for antimicrobial and anticancer activities. The three most abundant genera identified were Streptomyces, Actinomadura, and Micromonospora. Phylogenetic analyses of the marine OTUs isolated indicated that the Madeira Archipelago is a new source of actinomycetes adapted to life in the ocean. Phylogenetic differences between offshore (>100 m from shore) and nearshore (< 100 m from shore) populations illustrates the importance of sampling offshore in order to isolate new and diverse bacterial strains. Novel phylotypes from chemically rich marine actinomycete groups like MAR4 and the genus Salinispora were isolated. Anticancer and antimicrobial assays identified Streptomyces, Micromonospora, and Salinispora as the most biologically active genera. This study illustrates the importance of bioprospecting efforts at unexplored regions of the ocean to recover bacterial strains with the potential to produce novel and interesting chemistry.

  13. Biotic paleothermometry constrains on Arctic plates reconstructions: Carboniferous and Permian (Zhokhov Island, De-Longa Group Islands, New Siberian Archipelago)

    NASA Astrophysics Data System (ADS)

    Davydov, Vladimir I.

    2016-09-01

    A warm-water fauna and flora from a Carboniferous limestone xenolith that was captured during penetration of deep intraplate Cenozoic basalts through a Paleozoic carbonate platform have been found on Zhokhov Island, New Siberian Archipelago (NSA). This limestone xenolith contains a very high taxonomic diversity of Moscovian (Middle Pennsylvanian) tropical foraminifera and calcareous algae. As this warm-water biota never occurs north of the forbiddance line, i.e., 30-35°N/S, this fauna and algal flora constrain the paleogeography and interpretation of the paleotectonics in the region. Thus, the location of the most of the New Siberian Archipelago islands at that time must have been within tropics or subtropics. Analyses of the existing data on fusulinid distribution within the Arctic region indicate that Zhokhov and Wrangel Islands were still a part of Alaska-Chukotka composite terrane as late as in the Artinskian. Both fusulinid and detrital zircon provenance data suggest that the Chukotka microplate, NSA, and Wrangel Island probably were close to Arctic Alaska until Triassic time. The fusulinids from the Mankomen Formation and other formations in Wrangelia show a strong affinity with the Uralo-Franklinian province regions including the Sverdrup Basin, Spitsbergen, Barents Sea, and Timan-Pechora and the northern-central Urals rather than with northern Panthalassa.

  14. The Madeira Archipelago As a Significant Source of Marine-Derived Actinomycete Diversity with Anticancer and Antimicrobial Potential

    PubMed Central

    Prieto-Davó, Alejandra; Dias, Tiago; Gomes, Sofia E.; Rodrigues, Sara; Parera-Valadez, Yessica; Borralho, Pedro M.; Pereira, Florbela; Rodrigues, Cecilia M. P.; Santos-Sanches, Ilda; Gaudêncio, Susana P.

    2016-01-01

    Marine-derived actinomycetes have demonstrated an ability to produce novel compounds with medically relevant biological activity. Studying the diversity and biogeographical patterns of marine actinomycetes offers an opportunity to identify genera that are under environmental pressures, which may drive adaptations that yield specific biosynthetic capabilities. The present study describes research efforts to explore regions of the Atlantic Ocean, specifically around the Madeira Archipelago, where knowledge of the indigenous actinomycete diversity is scarce. A total of 400 actinomycetes were isolated, sequenced, and screened for antimicrobial and anticancer activities. The three most abundant genera identified were Streptomyces, Actinomadura, and Micromonospora. Phylogenetic analyses of the marine OTUs isolated indicated that the Madeira Archipelago is a new source of actinomycetes adapted to life in the ocean. Phylogenetic differences between offshore (>100 m from shore) and nearshore (< 100 m from shore) populations illustrates the importance of sampling offshore in order to isolate new and diverse bacterial strains. Novel phylotypes from chemically rich marine actinomycete groups like MAR4 and the genus Salinispora were isolated. Anticancer and antimicrobial assays identified Streptomyces, Micromonospora, and Salinispora as the most biologically active genera. This study illustrates the importance of bioprospecting efforts at unexplored regions of the ocean to recover bacterial strains with the potential to produce novel and interesting chemistry. PMID:27774089

  15. Extent of mangrove nursery habitats determines the geographic distribution of a coral reef fish in a South-Pacific archipelago.

    PubMed

    Paillon, Christelle; Wantiez, Laurent; Kulbicki, Michel; Labonne, Maylis; Vigliola, Laurent

    2014-01-01

    Understanding the drivers of species' geographic distribution has fundamental implications for the management of biodiversity. For coral reef fishes, mangroves have long been recognized as important nursery habitats sustaining biodiversity in the Western Atlantic but there is still debate about their role in the Indo-Pacific. Here, we combined LA-ICP-MS otolith microchemistry, underwater visual censuses (UVC) and mangrove cartography to estimate the importance of mangroves for the Indo-Pacific coral reef fish Lutjanus fulviflamma in the archipelago of New Caledonia. Otolith elemental compositions allowed high discrimination of mangroves and reefs with 83.8% and 98.7% correct classification, respectively. Reefs were characterized by higher concentrations of Rb and Sr and mangroves by higher concentrations of Ba, Cr, Mn and Sn. All adult L. fulviflamma collected on reefs presented a mangrove signature during their juvenile stage with 85% inhabiting mangrove for their entire juvenile life (about 1 year). The analysis of 2942 UVC revealed that the species was absent from isolated islands of the New Caledonian archipelago where mangroves were absent. Furthermore, strong positive correlations existed between the abundance of L. fulviflamma and the area of mangrove (r = 0.84 for occurrence, 0.93 for density and 0.89 for biomass). These results indicate that mangrove forest is an obligatory juvenile habitat for L. fulviflamma in New Caledonia and emphasize the potential importance of mangroves for Indo-Pacific coral reef fishes.

  16. Conservation Genetics of the Philippine Tarsier: Cryptic Genetic Variation Restructures Conservation Priorities for an Island Archipelago Primate

    PubMed Central

    Brown, Rafe M.; Weghorst, Jennifer A.; Olson, Karen V.; Duya, Mariano R. M.; Barley, Anthony J.; Duya, Melizar V.; Shekelle, Myron; Neri-Arboleda, Irene; Esselstyn, Jacob A.; Dominy, Nathaniel J.; Ong, Perry S.; Moritz, Gillian L.; Luczon, Adrian; Diesmos, Mae Lowe L.; Diesmos, Arvin C.; Siler, Cameron D.

    2014-01-01

    Establishment of conservation priorities for primates is a particular concern in the island archipelagos of Southeast Asia, where rates of habitat destruction are among the highest in the world. Conservation programs require knowledge of taxonomic diversity to ensure success. The Philippine tarsier is a flagship species that promotes environmental awareness and a thriving ecotourism economy in the Philippines. However, assessment of its conservation status has been impeded by taxonomic uncertainty, a paucity of field studies, and a lack of vouchered specimens and genetic samples available for study in biodiversity repositories. Consequently, conservation priorities are unclear. In this study we use mitochondrial and nuclear DNA to empirically infer geographic partitioning of genetic variation and to identify evolutionarily distinct lineages for conservation action. The distribution of Philippine tarsier genetic diversity is neither congruent with expectations based on biogeographical patterns documented in other Philippine vertebrates, nor does it agree with the most recent Philippine tarsier taxonomic arrangement. We identify three principal evolutionary lineages that do not correspond to the currently recognized subspecies, highlight the discovery of a novel cryptic and range-restricted subcenter of genetic variation in an unanticipated part of the archipelago, and identify additional geographically structured genetic variation that should be the focus of future studies and conservation action. Conservation of this flagship species necessitates establishment of protected areas and targeted conservation programs within the range of each genetically distinct variant of the Philippine tarsier. PMID:25136854

  17. Extent of Mangrove Nursery Habitats Determines the Geographic Distribution of a Coral Reef Fish in a South-Pacific Archipelago

    PubMed Central

    Paillon, Christelle; Wantiez, Laurent; Kulbicki, Michel; Labonne, Maylis; Vigliola, Laurent

    2014-01-01

    Understanding the drivers of species' geographic distribution has fundamental implications for the management of biodiversity. For coral reef fishes, mangroves have long been recognized as important nursery habitats sustaining biodiversity in the Western Atlantic but there is still debate about their role in the Indo-Pacific. Here, we combined LA-ICP-MS otolith microchemistry, underwater visual censuses (UVC) and mangrove cartography to estimate the importance of mangroves for the Indo-Pacific coral reef fish Lutjanus fulviflamma in the archipelago of New Caledonia. Otolith elemental compositions allowed high discrimination of mangroves and reefs with 83.8% and 98.7% correct classification, respectively. Reefs were characterized by higher concentrations of Rb and Sr and mangroves by higher concentrations of Ba, Cr, Mn and Sn. All adult L. fulviflamma collected on reefs presented a mangrove signature during their juvenile stage with 85% inhabiting mangrove for their entire juvenile life (about 1 year). The analysis of 2942 UVC revealed that the species was absent from isolated islands of the New Caledonian archipelago where mangroves were absent. Furthermore, strong positive correlations existed between the abundance of L. fulviflamma and the area of mangrove (r = 0.84 for occurrence, 0.93 for density and 0.89 for biomass). These results indicate that mangrove forest is an obligatory juvenile habitat for L. fulviflamma in New Caledonia and emphasize the potential importance of mangroves for Indo-Pacific coral reef fishes. PMID:25140697

  18. Phylogeny of the island archipelago frog genus Sanguirana: Another endemic Philippine radiation that diversified 'Out-of-Palawan'.

    PubMed

    Brown, Rafe M; Su, Yong-Chao; Barger, Brenna; Siler, Cameron D; Sanguila, Marites B; Diesmos, Arvin C; Blackburn, David C

    2016-01-01

    Recent higher-level frog phylogenetic analyses have included a few members of the endemic Philippine frog genus Sanguirana. Although the monophyly of the group has never been disputed, the recent phylogenetically-supported inclusion of the Palawan Wood Frog (Sanguirana sanguinea) in this clade was highly unexpected. In addition, species boundaries and relationships remain unclear and new species continue to be discovered. We estimate the phylogeny for this endemic Philippine genus using two mitochondrial gene regions and six nuclear loci and complete sampling for all known species. We use a time-calibrated Bayesian estimate of phylogeny and model-testing approach to biogeographic inference to infer ancestral areas and probable means of diversification. These analyses identify Sanguirana as an additional clade for which the 'Out-of-Palawan' biogeographic scenario is unambiguously preferred. This study lends additional support to recent work suggesting that a substantial portion of Philippine vertebrate megadiversity originated via colonization of the archipelago from the Palawan microcontinent, with subsequent invasion of oceanic islands (e.g., range expansion over Huxley's Modification of Wallace's Line), numerous instances of overwater dispersal, and geographic radiation across the archipelago. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Multisensor and multitemporal data from Landsat images to detect damage to coral reefs, small islands in the Spermonde archipelago, Indonesia

    NASA Astrophysics Data System (ADS)

    Nurdin, Nurjannah; Komatsu, Teruhisa; Agus; Akbar AS, M.; Djalil, Abdul Rasyid; Amri, Khairul

    2015-06-01

    Coral reefs are important because of their high biodiversity and their key role in the tropical marine biosphere. Furthermore, coral reefs are very valuable as a socioeconomic resource as they make important contributions to the gross domestic product of many countries. Thus, it is very important to monitor dynamic spatial distributions of coral reefs and related habitats dominated by coral rubble, dead coral, and bleached corals. Despite these natural and socio-economic advantages, many factors are threatening coral reefs. The study site was selected in Spermonde archipelago, South Sulawesi, Indonesia because this area is included in the Coral Triangle, recognized as the epicenter of coral diversity and a priority for conservation. Images of Landsat MSS, Landsat TM, Landsat ETM, Landsat ETM+, and Landsat 8 data were used to examine changes in the coral reefs of Suranti Island in the Spermonde Archipelago during forty one years from 1972 to 2013. The image processing includes gap fills, atmospheric corrections, geometric corrections, image composites, water column corrections, unsupervised classifications, and reclassifications. Fill Gap processing was done on Landsat ETM+ SLC-off. Subsequently, a multi-component change detection procedure was applied to define changes. Shallow water bottom types classification was divided into live coral, rubble and sand habitats, dead coral with algae, rubble, and sand. Preliminary results showed significant changes during the period 1972-2013 as well as changes in coral reefs, likely explained partly by destructive fishing practices.

  20. Elucidating the multiple genetic lineages and population genetic structure of the brooding coral Seriatopora (Scleractinia: Pocilloporidae) in the Ryukyu Archipelago

    NASA Astrophysics Data System (ADS)

    Nakajima, Yuichi; Nishikawa, Akira; Iguchi, Akira; Nagata, Tomofumi; Uyeno, Daisuke; Sakai, Kazuhiko; Mitarai, Satoshi

    2017-06-01

    The elucidation of species diversity and connectivity is essential for conserving coral reef communities and for understanding the characteristics of coral populations. To assess the species diversity, intraspecific genetic diversity, and genetic differentiation among populations of the brooding coral Seriatopora spp., we conducted phylogenetic and population genetic analyses using a mitochondrial DNA control region and microsatellites at ten sites in the Ryukyu Archipelago, Japan. At least three genetic lineages of Seriatopora (Seriatopora-A, -B, and -C) were detected in our specimens. We collected colonies morphologically similar to Seriatopora hystrix, but these may have included multiple, genetically distinct species. Although sexual reproduction maintains the populations of all the genetic lineages, Seriatopora-A and Seriatopora-C had lower genetic diversity than Seriatopora-B. We detected significant genetic differentiation in Seriatopora-B among the three populations as follows: pairwise F ST = 0.064-0.116 (all P = 0.001), pairwise G''ST = 0.107-0.209 (all P = 0.001). Additionally, only one migrant from an unsampled population was genetically identified within Seriatopora-B. Because the peak of the settlement of Seriatopora larvae is within 1 d and almost all larvae are settled within 5 d of spawning, our observations may be related to low dispersal ability. Populations of Seriatopora in the Ryukyu Archipelago will probably not recover unless there is substantial new recruitment from distant populations.

  1. Distribution and source apportionment of polycyclic aromatic hydrocarbons in surface sediments from Zhoushan Archipelago and Xiangshan Harbor, East China Sea.

    PubMed

    Wang, Xiaoyan; Xu, Huanzhi; Zhou, Yongdong; Wu, Changwen; Kanchanopas-Barnette, Praparsiri

    2015-12-30

    Zhoushan Archipelago and the adjacent Xiangshan Harbor are important commercial, tourism, fishing, and mariculture areas. Considering the concern on the effects of anthropogenic activities on the environment, the level and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments were investigated. The sum of 16 PAH (∑16 PAH) concentrations in the Zhoushan Archipelago ranged from 3.67 to 31.30 ng g(-1) d.w., with a mean of 15.01 ± 1.21 ng g(-1) d.w., and that in Xiangshan Harbor varied from 11.58 to 481.44 ng g(-1) d.w., with a mean of 62.52 ± 32.85 ng g(-1) d.w. Diagnostic ratios and factor analysis were performed to identify PAH sources. Results show that PAHs have mixed origins (i.e., traffic-related sources, coal combustion, petrogenic sources, and biomass burning), with pyrolytic-related pollution as the dominant source. This study provided a baseline to promote environmental protection and pollution episode monitoring in the East China Sea. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Magmatic activity at Islas Marias Archipelago, Gulf of California: Oceanic lithosphere with gabbroic sills versus Jurassic-Cretaceous arc components.

    NASA Astrophysics Data System (ADS)

    Schaaf, P. E. G.; Solis-Pichardo, G.; Hernandez-Trevino, T.; Villanueva, D.; Arrieta, G. F.; Rochin, H.; Rodriguez, L. F.; Bohnel, H.; Weber, B.

    2015-12-01

    Islas Marias Archipelago consists of four islands located in the mouth of the Gulf of California. Lithologically three of them (Maria Madre, San Juanito, and Maria Cleofas) are quite similar with a 165-170 Ma metamorphic basement, 75-85 Ma intrusive and extrusive rocks, and a sedimentary sandstone cover, which according to its foraminiferous content recorded multiple uplift and subsidence events related to the opening of the Gulf. However, these units are absent on Maria Magdalena island which is positioned between the other islands. Here, instead, oceanic lithosphere with pillow lavas and gabbroic sills, intercalated with sandstones form the dominant outcrops. Their geochemical and isotopic characteristics are similar to N-MORB with epsilon Nd values around +10 and 87Sr/86Sr of 0.70290. The gabbros are not older than 22 Ma. Magdalena island was obviously uplifted separately from the other islands of the archipelago, probably along a now hidden transform fault system along the East Pacific Rise. Metamorphic and igneous rocks of the other islands can be correlated to lithologically similar units in the Los Cabos Block, Baja California, or to the continental margin units in Sinaloa, Nayarit and Jalisco states when looking at their geochemical and geochronological signatures. Paleomagnetic studies on 35 sampling sites from all 4 islands give evidence for relatively small scale tectonic movements.

  3. Hawai'i Coral Disease database (HICORDIS): species-specific coral health data from across the Hawaiian archipelago.

    PubMed

    Caldwell, Jamie M; Burns, John H R; Couch, Courtney; Ross, Megan; Runyon, Christina; Takabayashi, Misaki; Vargas-Ángel, Bernardo; Walsh, William; Walton, Maya; White, Darla; Williams, Gareth; Heron, Scott F

    2016-09-01

    The Hawai'i Coral Disease database (HICORDIS) houses data on colony-level coral health condition observed across the Hawaiian archipelago, providing information to conduct future analyses on coral reef health in an era of changing environmental conditions. Colonies were identified to the lowest taxonomic classification possible (species or genera), measured and assessed for visual signs of health condition. Data were recorded for 286,071 coral colonies surveyed on 1819 transects at 660 sites between 2005 and 2015. The database contains observations for 60 species from 22 genera with 21 different health conditions. The goals of the HICORDIS database are to: i) provide open access, quality controlled and validated coral health data assembled from disparate surveys conducted across Hawai'i; ii) facilitate appropriate crediting of data; and iii) encourage future analyses of coral reef health. In this article, we describe and provide data from the HICORDIS database. The data presented in this paper were used in the research article "Satellite SST-based Coral Disease Outbreak Predictions for the Hawaiian Archipelago" (Caldwell et al., 2016) [1].

  4. Population Genetic Structure of the Deep-Sea Precious Coral Corallium secundum from the Hawaiian Archipelago Based on Microsatellites.

    NASA Astrophysics Data System (ADS)

    Baco-Taylor, A.

    2006-12-01

    Deep-sea precious corals (Gerardia sp., Corallium lauuense, and Corallium secundum) on the Islands and seamounts of the Hawaiian Archipelago have supported an extremely profitable fishery, yet little is known about the life history and dispersal of the exploited species. Recent studies indicate significant genetic structure between shallow-water coral populations, including several species capable of long distance dispersal. If significant genetic structure exists in seamount and Island populations of precious corals, this could suggest that the elimination (through overharvesting) of a bed of precious corals would result in loss of overall genetic diversity in the species. Here I discuss results based on microsatellite studies of the precious coral, Corallium secundum, from 11 sites in the Hawaiian Archipelago collected between 1998 and 2004, and compare the population genetic structure and dispersal capabilities of Corallium secundum to the results for Corallium lauuense. Microsatellite studies of Corallium lauuense indicated significant heterozygote deficiency in most populations, suggesting recruitment in most populations is from local sources with only occasional long-distance dispersal events. Also, two populations appear to be significantly isolated from other populations of Corallium lauuense and may be separate stocks. In contrast, Corallium secundum populations have little heterozygote deficiency and separate into 3 distinct regions. In addition to having fisheries management implications for these corals, the results of these studies also have implications for the management and protection of seamount fauna.

  5. Zonation and spatial distribution of littoral fish communities from the southwestern Finnish coast (Archipelago and Bothnian Sea, Northern Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Vahteri, Petri; O'Brien, Kevin; Vuorinen, Ilppo

    2009-03-01

    The aim of our study was to test whether the distribution of littoral fish assemblages would reflect both their immediate environment with reference to local underwater vegetation, including larger scale geographic archipelagial zonation. A total of 62 locations were sampled using beach seine and underwater video along the southwestern Finnish coastline in summer 2001. At all locations, water temperature, water transparency and benthic vegetation patterns (depth ranges of plant species or taxa) were recorded. Using correspondence analysis, our results showed a clear division of the Archipelago Sea into three separate zones based on littoral fish species assemblages. Overall, fish assemblages formed three distinct site groups, being dominated by pike and cyprinids, by percids and gobies, or by gasterosteids, and showed clear inner, middle and outer archipelago zones respectively, within the study area. Our results suggest that while vegetation in the study sites was diverse, it failed to express the zonation reflected by the littoral fish assemblages, which showed a definite zonation pattern which broadly reflected previous reports using both physical and biological parameters. We interpret our results to show that littoral vegetation is better in expressing small-scale differences between study sites, while littoral fish communities are more robust in detecting changes over a larger geographical scale.

  6. Spatio-temporal variation in the diet of Cory's shearwater Calonectris diomedea in the Azores archipelago, northeast Atlantic

    NASA Astrophysics Data System (ADS)

    Neves, Verónica; Nolf, Dirk; Clarke, Malcolm

    2012-12-01

    The diet of Cory's shearwater Calonectris diomedea in the Azores was studied in four islands of the archipelago over four breeding seasons, using stomach flushings from 959 birds. Fish were identified from flesh, otoliths and vertebrae and cephalopods from flesh and lower beaks. The frequency of occurrence of prey taxa, and the numerical frequency of fish and cephalopods, showed marked variations both spatially, across the breeding cycle and between years. Overall, cephalopods from 37 species representing 17 families and fish from 33 species representing 18 families were identified, representing over 70 prey species and trebling what was previously known. Histioteuthidae, Ommastrephidae and Cranchiidae were the only cephalopod families present every year and represented two thirds of the cephalopods' consumption by number. Blue jack mackerel Trachurus picturatus was the most abundant prey species present in 1998 and 2002 but was absent in 1999 and 2000, representing on average 57.2% of prey by number in the years it occurred. Apart from blue jack mackerel, most fish species were present in very low numbers with the exception of Cubiceps gracilis, Scomberesox saurus and Maurolicus muellerii. Diaphus adenomus, was recorded for the first time for the Azores archipelago.

  7. Conservation genetics of the Philippine tarsier: cryptic genetic variation restructures conservation priorities for an island archipelago primate.

    PubMed

    Brown, Rafe M; Weghorst, Jennifer A; Olson, Karen V; Duya, Mariano R M; Barley, Anthony J; Duya, Melizar V; Shekelle, Myron; Neri-Arboleda, Irene; Esselstyn, Jacob A; Dominy, Nathaniel J; Ong, Perry S; Moritz, Gillian L; Luczon, Adrian; Diesmos, Mae Lowe L; Diesmos, Arvin C; Siler, Cameron D

    2014-01-01

    Establishment of conservation priorities for primates is a particular concern in the island archipelagos of Southeast Asia, where rates of habitat destruction are among the highest in the world. Conservation programs require knowledge of taxonomic diversity to ensure success. The Philippine tarsier is a flagship species that promotes environmental awareness and a thriving ecotourism economy in the Philippines. However, assessment of its conservation status has been impeded by taxonomic uncertainty, a paucity of field studies, and a lack of vouchered specimens and genetic samples available for study in biodiversity repositories. Consequently, conservation priorities are unclear. In this study we use mitochondrial and nuclear DNA to empirically infer geographic partitioning of genetic variation and to identify evolutionarily distinct lineages for conservation action. The distribution of Philippine tarsier genetic diversity is neither congruent with expectations based on biogeographical patterns documented in other Philippine vertebrates, nor does it agree with the most recent Philippine tarsier taxonomic arrangement. We identify three principal evolutionary lineages that do not correspond to the currently recognized subspecies, highlight the discovery of a novel cryptic and range-restricted subcenter of genetic variation in an unanticipated part of the archipelago, and identify additional geographically structured genetic variation that should be the focus of future studies and conservation action. Conservation of this flagship species necessitates establishment of protected areas and targeted conservation programs within the range of each genetically distinct variant of the Philippine tarsier.

  8. Preliminary results of teleseismic double-difference relocation of earthquakes around Indonesian archipelago region

    SciTech Connect

    Nugraha, Andri Dian Widiyantoro, Sri; Shiddiqi, Hasbi Ash; Ramdhan, Mohamad; Wandono,; Sutiyono,; Handayani, Titi; Nugroho, Hendro

    2015-04-24

    Indonesian archipelago region is located in active tectonic setting and high seismicity zone. During the last decade, Indonesian was experienced with destructive major earthquakes causing damage and victims. The information of precise earthquake location parameters are very important in partular for earthquake early warning to the society and for advance seismic studies. In this study, we attempted to improve hypocenter location compiled by BMKG for time periods of April, 2009 up to June, 2014 for about 22,000 earthquake events around Indonesian region. For the firts time, we applied teleseismic double-difference relocation algorithm (teletomoDD) to improve hypocenter region in Indonesia region combining regional and teleseismic stations. Hypocenter relocation was performed utilizing local, regional, and teleseismic P-wave arrival time data. Our relocation result show that travel-time RMS errors were greatly reduced compared to the BMKG catalog. Seismicity at shallower depth (less than 50 km) shows significantly improvement especially in depth, and refined shallow geological structures, e.g. trench and major strike slip faults. Clustered seismicity is also detected beneath volcanic region, and probably related volcano activities and also major faults nearby. In the Sunda arc region, seismicity at shallower depth centered at two major distributions parallel to the trench strike direction, i.e. around fore-arc and in mainland that related to major fault, e.g. the Sumatran fault, and volcanic fronts. Below Central Java region, relocated hypocenter result showed double seismic zone pattern. A seismic gap is detected around the Sunda-Banda transition zone where transition between oceanic subduction to continental crust collision of Australian plate occurs. In Eastern Indonesia region, shallow earthquakes are observed related to major strike slip faults, e.g. Sorong and Palu-Koro fault, volcanism, and shallow part of subduction and collision zones. We also compare our

  9. [Hurricane Paloma's effects on seagrasses along Jardines de la Reina Archipelago, Cuba].

    PubMed

    Guimarais, Mayrene; Zúñiga, Adán; Pina, Fabián; Matos, Felipe

    2013-09-01

    Seagrasses are one of the most important coastal ecosystems since they promote organic matter flow, nutrient cycling, food availability and refuge. Until now, reports on damages caused by storms and hurricanes on seagrass beds are uncommon and highly variable. The seagrass meadows of the East end of Jardines de la Reina archipelago were surveyed from Nov. 29th to Dec. 5th of 2008, in order to determinate the effects from the passing of Hurricane Paloma: a category three storm on the Saffir-Simpsom scale. A rapid field assessment of the affected areas was carried out using the manta tow technique. In six sites, seagrass was quantitatively evaluated using a 15cm diameter core (four sampling units per site) and shoot density was calculated. Remote sensing techniques were used to estimate seagrass cover. To estimate the percentage of affected areas, a Region of Interest (ROI) was first created over a Landsat image. The percentage of seagrass affected within the ROI was estimated through direct georeferentiation of the contours of the damaged area and with a comparison to the total seagrass extension. To find possible explanations for damages, a false colour image was created using the near infrared band, to highlight the differences between emerged and submerged zones. The direction of winds was estimated using ArcGis 9.2 creating circular buffers, from the centre of the hurricane and generating lines tangent to the buffers. Seagrass in the region was dominated by the angiosperm Thalassia testudinum. Regional mean density was 1 321 +/- 721 shoots/m2, a value regarded as high for the Caribbean area. Seagrass meadows were partly affected by sediment accumulation on the shoots of T. testudinum and uprooting rhizomes. The 7.6 km2 disturbed area represented 1% of the total seagrass area. Other sites, closer to the centre of the hurricane, did not show any damages on the marine vegetation. The keys location with respect to the hurricane track was the most likely cause of the

  10. Quaternary tectonic stability of the Bahamian archipelago: evidence from fossil coral reefs and flank margin caves

    NASA Astrophysics Data System (ADS)

    Carew, James L.; Mylroie, John E.

    Throughout the islands of the Bahamian archipelago fossil coral reefs are found from current sea level up to a maximum elevation of +4 m. {234U}/{230Th} radiometric dates obtained from in situ corals from these reefs, by both alpha-count and mass-spectrometric techniques, indicates that they were all formed during Oxygen Isotope Substage 5e (ca. 125,000 years ago). Those data are consistent with a maximum sea-level highstand of +6 m during Substage 5e, and either no vertical motion of the Bahamas, or possible isostatic subsidence of up to 2 m during the past 120,000 years. No older in situ fossil corals, or other subtidal deposits, have been found subaerially exposed anywhere in the Bahamas. That finding suggests that late Quaternary (at least the past 300,000 years) isostatic subsidence has occurred at a rate of 1-2 m per hundred thousand years, and/or no pre-5e highstands were above modern sea level. An independent corroboration of the conclusions drawn about sea level amplitude and tectonic stability of the Bahamas from the coral reef data is available from examination of abundant flank margin caves (horizontal, phreatic dissolution caves) found above modern sea level throughout the Bahamas. These horizontally extensive air-filled caves have dissolutional ceilings with elevations that are restricted to +1 to +7 m, which is consistent with formation at the margin of a thin freshwater lens elevated by a past +6 m sea-level highstand. The restricted cave elevations, and the lack of stalagmites in these caves that are older than 100,000 years, are also consistent with cave formation during Substage 5e, and possible subsequent isostatic subsidence of a few metres. The subsurface geology of the southeastern Bahamas contains a long-term record (millions of years) that has been attributed to past tectonic activity along the North American/Caribbean plate boundary. While that record suggests differential subsidence across the Bahamas in the Tertiary Period, the data from

  11. Sources of Dimethyl Sulfide in the Canadian Arctic Archipelago and Baffin Bay

    NASA Astrophysics Data System (ADS)

    Mungall, E. L.; Croft, B.; Lizotte, M.; Thomas, J. L.; Murphy, J. G.; Levasseur, M.; Martin, R.; Wentzell, J. J. B.; Liggio, J.; Abbatt, J.

    2015-12-01

    Dimethyl sulfide plays a major role in the global sulfur cycle, meaning that it is important to the formation of sulfate aerosol and thus to cloud condensation nuclei populations and cloud formation. The summertime Arctic atmosphere sometimes resides in a cloud condensation nuclei limited regime, making it very susceptible to changes in their number. Despite the interest generated by this situation, dimethyl sulfide has only rarely been measured in the summertime Arctic. This work presents the first high time resolution (10 Hz) DMS mixing ratio measurements for the Eastern Canadian Archipelago and Baffin Bay in summer performed on an icebreaker cruise as one component of the Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments (NETCARE). Measured mixing ratios ranged from below the detection limit of 4 pptv to 1155 pptv with a median value of 186 pptv. We used transfer velocity parameterizations from the literature to generate the first flux estimates for this region in summer, which ranged from 0.02-12 μmol m-2 d-1. DMS has a lifetime against OH oxidation of 1-2 days, allowing both local sources and transport to play roles in its atmospheric mixing ratio. Through air mass trajectory analysis using FLEXPART-WRF and chemical transport modeling using GEOS-Chem, we have identified the relative contributions of local sources (Lancaster Sound and Baffin Bay) as well as transport from further afield (the Hudson Bay System and the Beaufort Sea) and find that the local sources dominate. GEOS-Chem is able to reproduce the major features of the measured time series, but is biased low overall (median 72 pptv). We discuss non-marine sources that could account for this low bias and estimate the possible contributions to DMS mixing ratios from lakes, biomass burning, melt ponds and coastal tundra. Our results show that local marine sources of DMS dominate the summer Arctic atmosphere, but that non-local and possibly non

  12. Benthic macroinfaunal community structure, resource utilisation and trophic relationships in two Canadian Arctic Archipelago polynyas.

    PubMed

    Mäkelä, Anni; Witte, Ursula; Archambault, Philippe

    2017-01-01

    Climate change driven alterations to patterns of Arctic marine primary production, with increasing phytoplankton- and decreasing ice algal production, have the potential to change the resource utilisation and trophic structure of the benthic communities relying on the algae for food. To predict the benthic responses to dietary changes, we studied the macroinfaunal community compositions, and used the faunal δ13C and δ15N signatures to investigate their main food sources and trophic positions in North Water (NOW) and Lancaster Sound (LS) polynyas in the Canadian Arctic Archipelago. Macroinfaunal density (10 952 ind. m-2) and biomass (3190 mg C m-2) recorded in NOW were higher than previously found in the Arctic at depths >500m, and significantly higher than in LS (8355 ind. m-2 and 2110 mg C m-2). This was attributed to higher particulate organic matter fluxes to seafloor in NOW. Polychaetes were significant taxa at both sites in terms of density and biomass, and in addition crustacean density in NOW and bivalve density in LS were high. Facultative filter and surface deposit feeders were highly prevalent at both sites, suggesting feeding plasticity is a successful strategy for accessing different food sources. The macrofaunal δ13C signatures reflected the signatures of pelagic particulate organic matter at the sites, and an isotope mixing model confirmed phytoplankton as the main food source for most taxa and feeding guilds. The food web length in LS was longer than in NOW (3.2 vs. 2.8 trophic levels). This was attributed to a larger reliance on reworked organic matter by the benthic community in LS, whereas the high export fluxes at the highly productive NOW resulted in higher rates of selective consumption of fresh algal matter. Despite studies suggesting that loss of ice algae from consumer diets in the Arctic might have a negative impact on the benthos, this study suggests that Arctic macrobenthic communities thrive using phytoplankton as their main food

  13. Islas Marias Archipelago, Mexico. A Missing Piece to Reconstruct the Paleoposition of Baja California

    NASA Astrophysics Data System (ADS)

    Schaaf, P. E.; Pompa, V.; Hernandez, T.; Weber, B.; Solis, G.; Villanueva, D.; Perez-Venzor, J.

    2011-12-01

    Paleopositions for southern Baja California peninsula have yielded controversial models over the past 30 years. Mainly based on paleomagnetic data many hypotheses place Baja at lower paleolatitudes in front of southern Mexico or Central America with subsequent northward translations. Other models suggest minor, if any, northward displacements with respect to continental Mexico combined with clockwise rotations. Lithological, geochemical, and geochronological similarities for southern Baja California and Puerto Vallarta (western Mexico Pacific margin) igneous rocks seem to confirm the latter model. To further prove this model we have mapped and collected rocks from Maria Madre, the largest island of the Islas Marias archipelago, located in the mouth of the Gulf of California. In an area of only 145 square kilometers, metamorphic basements rocks (ortho and migmatitic gneisses), highly deformed metasediments, granitoids, acid to intermediate volcanic sequences, and a cover with gently folded marine sediments are exposed. The basement complex with gneisses and metasediments, including garnet-bearing paragneiss and calc silicates, as well as the granodioritic-tonalitic intrusives display an extraordinary accordance with similar units observed in the Los Cabos Block (LCB) of Baja California Sur. Furthermore, U-Pb zircon ages of 162 and 170 Ma for the basement gneisses and of 80 Ma for the granitoids have been reported also from the LCB. Additionally, upper Cretaceous intrusive ages are well known from the Puerto Vallarta batholith in Jalisco and Nayarit, mainland Mexico. Geochemical and isotopic data as well as Nd model ages confirm a magmatic consanguinity of LCB, Islas Marias, and Puerto Vallarta granitoids. The volcanic units of Maria Madre Island include ignimbrites and effusive dacitic-rhyolithic rocks, which can be correlated to the Sierra Madre Occidental province and the Comundú Formation of Baja California. Age determinations are under work to confirm this

  14. Suboxic dolomite formation linked to the sedimentary Mn cycle, Archipelago Los Roques, Venezuela

    NASA Astrophysics Data System (ADS)

    Petrash, D.; Lalonde, S.; Gonzalez, G.; Gingras, M.; Konhauser, K.

    2013-12-01

    The preferential formation of Ca-rich dolomite precursors in modern peritidal environments has been associated with the degradation of buried microbial mats, with complexation of Ca and Mg cations by extracellular polysaccharides, and alkalinity generation, mostly through bacterial sulfate reduction. However, it remains unclear why Ca-dolomite would not occur in suboxic sediments where bacterial Mn(IV) and/or Fe(III) reduction are important sources of alkalinity, and the role, if any, of Fe- and Mn-recycling in its diagenetic stabilization to more stoichiometric dolomite is unknown. In a shoaling-upward parasequence in the Archipelago Los Roques, Venezuela, an abundance of Ca-dolomite coincides with a relative decrease in bulk-sediment iron concentrations. These sediments were analyzed with multiple analytical tools, including EPMA, ICP-MS, synchrotron-based XRF, XRD, and spatially resolved XANES. Results demonstrate that the distribution of spheroidal aggregates of nanometer-scale Ca-rich dolomite rhombohedra is linked with interstitial elemental sulfur and manganese accumulations, with Mn occurring in several oxidation states (Fig. 1). Based on our observations at this novel dolomite-forming site, we suggest that in peritidal settings the burial of metal-reactive microbial mats act as a barrier capable of concentrating dissolved reactive species that promote greater sediment residence times in suboxic (manganic) zones, where the recycling of Mn not only plays an important role in the remineralization of organic matter, but also sustains elevated alkalinity and dissolved pore water sulfide concentrations. The last two effects have been previously suggested to promote Mg dehydration, the major kinetic barrier to dolomite nucleation. Figure 1. Normalized Mn K-edge merged spectra of a 5 x 5 μm analytical area bearing dolomite cements. A: The K-edge exhibits two main features at about 6554 and 6558 eV. B: Intermediate Mn (III) is identified by the positive slope of

  15. Benthic macroinfaunal community structure, resource utilisation and trophic relationships in two Canadian Arctic Archipelago polynyas

    PubMed Central

    Witte, Ursula; Archambault, Philippe

    2017-01-01

    Climate change driven alterations to patterns of Arctic marine primary production, with increasing phytoplankton- and decreasing ice algal production, have the potential to change the resource utilisation and trophic structure of the benthic communities relying on the algae for food. To predict the benthic responses to dietary changes, we studied the macroinfaunal community compositions, and used the faunal δ13C and δ15N signatures to investigate their main food sources and trophic positions in North Water (NOW) and Lancaster Sound (LS) polynyas in the Canadian Arctic Archipelago. Macroinfaunal density (10 952 ind. m-2) and biomass (3190 mg C m-2) recorded in NOW were higher than previously found in the Arctic at depths >500m, and significantly higher than in LS (8355 ind. m-2 and 2110 mg C m-2). This was attributed to higher particulate organic matter fluxes to seafloor in NOW. Polychaetes were significant taxa at both sites in terms of density and biomass, and in addition crustacean density in NOW and bivalve density in LS were high. Facultative filter and surface deposit feeders were highly prevalent at both sites, suggesting feeding plasticity is a successful strategy for accessing different food sources. The macrofaunal δ13C signatures reflected the signatures of pelagic particulate organic matter at the sites, and an isotope mixing model confirmed phytoplankton as the main food source for most taxa and feeding guilds. The food web length in LS was longer than in NOW (3.2 vs. 2.8 trophic levels). This was attributed to a larger reliance on reworked organic matter by the benthic community in LS, whereas the high export fluxes at the highly productive NOW resulted in higher rates of selective consumption of fresh algal matter. Despite studies suggesting that loss of ice algae from consumer diets in the Arctic might have a negative impact on the benthos, this study suggests that Arctic macrobenthic communities thrive using phytoplankton as their main food

  16. Volcanic lakes of the Azores archipelago (Portugal): Geological setting and geochemical characterization

    NASA Astrophysics Data System (ADS)

    Cruz, J. V.; Antunes, P.; Amaral, C.; França, Z.; Nunes, J. C.

    2006-08-01

    A representative set of 30 lakes from the Azores archipelago (Portugal) has been studied to obtain data on their volcanic setting and water geochemistry. The majority of the studied lakes are located inside volcanic craters and subsidence calderas, while the remaining lakes are located in topographic depressions not associated with volcanic centres, in depressions of tectonic origin and inside lava caves. In general, the Azorean volcanic lakes are small, with surface areas between 8.94 × 10 - 4 km 2 and 4.35 km 2 and volumes between 2.4 × 10 3 and 4.78 × 10 7 m 3; median = 3.99 × 10 4 m 3, presenting maximum depths between 0.8 and 33 m. Mostly of the Na-Cl to Na-HCO 3 type, the lake waters are generally low temperature (11.9-24.6 °C), very dilute (TDS range between 11.0 and 356.2 mg/L; median = 36.8 mg/L) and a clear exception is Furna do Enxofre lake (Graciosa island) that shows a Mg trend. Two types of lake waters can be recognized: 1) one is characterized by Na/Cl ratio close to the seawater value and have evolved, and evolve by marine contribution; and 2) Na-HCO 3 type waters that, in addition to sea-salt input, have been influenced by other processes (e.g., water-rock interaction, hydrothermal seepage into the lake bottom) evident from higher total CO 2 content (365.1 mg/L) and SiO 2 content (74.9 mg/L), as well demonstrated by in the Furna do Enxofre lake. Nevertheless, volcanic contribution cannot be excluded for some lakes as Furna do Enxofre. Vertical profiles made at the deepest lakes of São Miguel reveal that major-ion content varies little with depth, largely independent of the occurrence of thermally driven density stratification in summer for some lakes. However, dissolved CO 2 increases with depth and is kept in the hypolimnion in summer, whereas the HCO 3- content is stable, suggesting that CO 2 release exceeds acidity neutralization by water-rock interaction. During winter, without stratification, the dissolved CO 2 increase is less sharp for

  17. Bird Pollination in an Angraecoid Orchid on Reunion Island (Mascarene Archipelago, Indian Ocean)

    PubMed Central

    MICHENEAU, CLAIRE; FOURNEL, JACQUES; PAILLER, THIERRY

    2006-01-01

    adaptations in the insular context of the Mascarene Archipelago. PMID:16554310

  18. Preliminary results of teleseismic double-difference relocation of earthquakes around Indonesian archipelago region

    NASA Astrophysics Data System (ADS)

    Nugraha, Andri Dian; Shiddiqi, Hasbi Ash; Widiyantoro, Sri; Ramdhan, Mohamad; Wandono, Sutiyono, Handayani, Titi; Nugroho, Hendro

    2015-04-01

    Indonesian archipelago region is located in active tectonic setting and high seismicity zone. During the last decade, Indonesian was experienced with destructive major earthquakes causing damage and victims. The information of precise earthquake location parameters are very important in partular for earthquake early warning to the society and for advance seismic studies. In this study, we attempted to improve hypocenter location compiled by BMKG for time periods of April, 2009 up to June, 2014 for about 22,000 earthquake events around Indonesian region. For the firts time, we applied teleseismic double-difference relocation algorithm (teletomoDD) to improve hypocenter region in Indonesia region combining regional and teleseismic stations. Hypocenter relocation was performed utilizing local, regional, and teleseismic P-wave arrival time data. Our relocation result show that travel-time RMS errors were greatly reduced compared to the BMKG catalog. Seismicity at shallower depth (less than 50 km) shows significantly improvement especially in depth, and refined shallow geological structures, e.g. trench and major strike slip faults. Clustered seismicity is also detected beneath volcanic region, and probably related volcano activities and also major faults nearby. In the Sunda arc region, seismicity at shallower depth centered at two major distributions parallel to the trench strike direction, i.e. around fore-arc and in mainland that related to major fault, e.g. the Sumatran fault, and volcanic fronts. Below Central Java region, relocated hypocenter result showed double seismic zone pattern. A seismic gap is detected around the Sunda-Banda transition zone where transition between oceanic subduction to continental crust collision of Australian plate occurs. In Eastern Indonesia region, shallow earthquakes are observed related to major strike slip faults, e.g. Sorong and Palu-Koro fault, volcanism, and shallow part of subduction and collision zones. We also compare our

  19. Seafloor features delineate Late Wisconsinan ice stream configurations in eastern Parry Channel, Canadian Arctic Archipelago

    NASA Astrophysics Data System (ADS)

    MacLean, B.; Blasco, S.; Bennett, R.; Lakeman, T.; Pieńkowski, A. J.; Furze, M. F. A.; Hughes Clarke, J.; Patton, E.

    2017-03-01

    Multibeam imagery and 3.5 kHz sub-bottom profiles acquired from CCGS Amundsen between 2003 and 2013 by ArcticNet and the Ocean Mapping Group at the University of New Brunswick provide information on seafloor features, geology, bathymetry and morphology in eastern Parry Channel and the adjoining large channels in the Canadian Arctic Archipelago. Together these include Peel Sound, Barrow Strait, Lancaster Sound, Wellington Channel, Prince Regent Inlet, Admiralty Inlet and Navy Board Inlet. Those data are in part complemented by high resolution single channel seismic reflection profiles acquired by the Geological Survey of Canada in the 1970s and 1980s and by sediment cores that provide chronological and depositional information. The occurrence and pattern of streamlined mega-scale ridge and groove lineations (MSGLs) indicate that these waterways were occupied by glacial ice streams in the past. Chronological information from marine and adjoining terrestrial areas suggests a long history of glacial events ranging in time from Early Pleistocene to Late Wisconsinan. Seafloor morphology and MSGL trends together with terrestrial ice flow patterns indicate that ice streams flowed into Barrow Strait from Peel Sound and Wellington Channel, and ice streams in Prince Regent, Admiralty and Navy Board inlets flowed northward into and eastward along Lancaster Sound. Recession of the ice stream westward along Parry Channel occurred ∼16 cal ka BP to 10.8 cal ka BP. Thick ice-contact sediments deposited by a late ice advance from Prince Regent Inlet constitute the seabed across a large area of western Lancaster Sound. Timing for that late ice advance appears to be bracketed between the 11.5 cal ka BP lift-off of the eastern Parry ice stream north of Prince Leopold Island and the ∼10.0 cal ka BP deglaciation of Prince Regent Inlet. Seafloor morphology and lineation trends suggest that ice delivered by the ice stream in Peel Sound was the westernmost tributary to the ice stream

  20. The First Paleomagnetic data from the Cambrian basalts of Henrietta Island (De Long Archipelago, Arctic Ocean)

    NASA Astrophysics Data System (ADS)

    Metelkin, D. V.; Zhdanova, A.; Vernikovskiy, V. A.; Matushkin, N. Y.

    2015-12-01

    Henrietta Island in De Long archipelago (East-Siberian sea) still remains poorly studied geologically but last investigations show that its volcano-sedimentary sequences can help reconstruct tectonic evolution of East Russian Arctic in Early Paleozoic stage. The deposits lying on Precambrian basements are deformed to varying degrees and intruded by mafic dykes.The study was carried out on two basaltic lava flows whose 40Ar/39Ar age is 520.6±9.5 Ma. Previously the age of these basalts was assumed Cretaceous. According to available data the underlaying sediments contain zircons with Cambrian and Ordovician ages but all boundaries between these basalts and other strata are tectonic. So we suppose the age of basalts as Middle Cambrian but more precise geochronological data are required. All magnetic measurements were performed at the Laboratory of Geodynamics and Paleomagnetism of Institute of Petroleum Geology and Geophysics (Novosibirsk). Basalt samples has relatively high magnetic susceptibility values varying from 5x10-4 to 180x10-4SI units. NRM values range is from 3 to 170 mA/m. Petromagnetic parameters including also coercive characteristics point at the good potentially preserving primary magnetization. Stepwise thermal demagnetization permits to isolate characteristic components of magnetization and calculate mean directions in two lava flows: 1. Ds=294.3°, Is=29.1°, K=81.1, α95=5.1; 2. Ds=301.0°, Is=28.3°, K=34.4, α95=7.9). The mean paleomagnetic pole has coordinates: Plat=20.9°, Plong = 42.6°, dp/dm=14.3/7.9. Paleolatitude was defined as 15.3° but the question of the hemisphere for De Long Islands is open yet. In case of south hemisphere in Middle Cambrian according to available paleomagnetic data De Long islands could be placed close to Taimyr margin of Siberia and in case of northern hemisphere they may be located near south (in present-day coordinates) margin of Siberia. The work was supported by grant RFBR 14-05-31399 and Russian Research Fund

  1. Paleomagnetism of Jurassic-Cretaceous basalts from the Franz Josef Land Archipelago: tectonic implications

    NASA Astrophysics Data System (ADS)

    Abashev, Victor; Mikhaltsov, Nikolay; Vernikovsky, Valery

    2015-04-01

    New paleomagnetic data were obtained from a total of 158 oriented samples collected from the Jurassic magmatic complexes exposed on the Franz Joseph Land Archipelago (FJL). The field work was conducted during 2011 field season. Present study was focused on the tholeiitic basaltic lava flows that crop out on the Hooker Island. The samples were subjected to a detailed step-wise thermal demagnetization in temperatures up to 600 deg C or alternating field demagnetization with maximum filed up to 140 mT. Natural remanent magnetization (NRM) was measured with a 2G cryogenic magnetometer or a JR-6A spin-magnetometer housed in a magnetically shielded room at the Institute of Petroleum Geology and Geophysics, Siberian Branch of Russian Academy of Sciences. The main NRM carriers in the FJL samples are titanomagnetites with varying Ti-content. Magnetic remanence was unblocked in temperatures of 350-400 deg C. Some samples are characterized by unblocking temperatures of 560 deg C. The new paleomagnetic data were combined with those previously obtained from the early Cretaceous volcanics exposed on the FJL. A new mean paleomagnetic direction for the Jurassic rocks was calculated as D=78.3 deg, I=74.7 deg, a95=3.1 deg, k=194.3, N=13. A corresponding paleomagnetic pole is now located at Plat=62.1 deg; Plon=136.5 deg, A95=5.5 deg, K=63.6. New results suggest that the JFL occupied a significantly different position from that of the present day. However, in early Cretaceous the JFL was already located close to its present day position. We propose a rifting event between the North Barentz terrane (FJL and possibly Svalbard) and the counterpart of European tectonic domain. The rifting occurred during Early-Middle Jurassic. This event was accompanied by a significant shift of the FJL to the north-east for approximately 500 km. New results are in good agreement with a hypothesis that the FJL was passing over the Icelandic-Siberian hot spot during the Jurassic-Cretaceous time

  2. A dearth of data on the mammals of the Madrean Archipelago: what do we think we know and what we actually do know

    Treesearch

    John L. Koprowski; Andrew J. Edelman; Bret S. Pasch; Debbie C. Beucher

    2005-01-01

    The Madrean Archipelago harbors one of the most diverse mammalian communities in North America. We used the Web of Science literature search tool to assess the diversity of peer-reviewed publications on mammals in Arizona and New Mexico as an indicator of publications in the region. The number of publications of all mammals was lower than expected with a mode of 0 and...

  3. A quantitative topographic analysis of the Sky Islands: a closer examination of the topography-biodiversity relationship in the Madrean Archipelago [Abstract

    Treesearch

    Dvid Coblentz; Kurt H. Riitters

    2005-01-01

    The well-documented relationship between topography and biodiversity is particularly profound in the Madrean Archipelago. However, despite this recognition, most studies of the Sky Island biogeography have used only a first-order qualitative description of the topography (e.g., average vertical relief and mean elevation). Exploiting the availability of high-resolution...

  4. A quantitative topographic analysis of the Sky Islands: a closer examination of the topography-biodiversity relationship in the Madrean Archipelago

    Treesearch

    David Coblentz; Kurt H. Riitters

    2005-01-01

    The relationship between topography and biodiversity is well documented in the Madrean Archipelago. However, despite this recognition, most biogeographical studies concerning the role of topography have relied primarily on a qualitative description of the landscape. Using an algorithm that operates on a high-resolution digital elevation model we present a quantitative...

  5. Archipelago colonization by ecologically dissimilar amphibians: evaluating the expectation of common evolutionary history of geographical diffusion in co-distributed rainforest tree frogs in islands of Southeast Asia.

    PubMed

    Gonzalez, Paulette; Su, Yong-Chao; Siler, Cameron D; Barley, Anthony J; Sanguila, Marites B; Diesmos, Arvin C; Brown, Rafe M

    2014-03-01

    Widespread, co-distributed species with limited relative dispersal abilities represent compelling focal taxa for comparative phylogeography. Forest vertebrates in island archipelagos often exhibit pronounced population structure resulting from limited dispersal abilities or capacity to overcome marine barriers to dispersal. The exceptionally diverse Old World tree frogs of the family Rhacophoridae have colonized the forested island archipelagos of Southeast Asia on multiple occasions, entering the islands of Indonesia and the Philippines via a "stepping stone" mode of dispersal along elongate island chains, separated by a series of marine channels. Here we evaluate the prediction that two tightly co-distributed Philippine rhacophorids colonized the archipelago during concomitant timescales and in the same, linear, "island-hopping" progression. We use a new multilocus dataset, utilize dense genetic sampling from the eastern arc of the Philippines, and we take a model-based phylogeographic approach to examining the two species for similar topological patterns of diversification, genetic structure, and timescales of diversification. Our results support some common mechanistic predictions (a general south-to-north polarity of colonization) but not others (timescale for colonization and manner and degree of lineage diversification), suggesting differing biogeographic scenarios of geographical diffusion through the archipelago and unique and idiosyncratic ecological capacities and evolutionary histories of each species.

  6. Scalable, chromatography-free synthesis of alkyl-tethered pyrene-based materials. Application to first-generation "archipelago model" asphaltene compounds.

    PubMed

    Diner, Colin; Scott, David E; Tykwinski, Rik R; Gray, Murray R; Stryker, Jeffrey M

    2015-02-06

    In this paper, we report a highly efficient, scalable approach to the total synthesis of conformationally unrestricted, electronically isolated arrays of alkyl-tethered polycyclic aromatic chromophores. This new class of modular molecules consists of polycyclic aromatic "islands" comprising significant structural fragments present in unrefined heavy petroleum, tethered together by short saturated alkyl chains, as represented in the "archipelago model" of asphaltene structure. The most highly branched archipelago compounds reported here share an architecture with first-generation dendrimeric constructs, making the convergent, chromatography-free synthesis described herein particularly attractive for further extensions in scope and applications to materials chemistry. The syntheses are efficient, selective, and readily adaptable to a multigram scale, requiring only inexpensive, "earth-abundant" transition-metal catalysts for cross-coupling reactions and extraction and fractional crystallization for purification. This approach avoids typical limitations in cost, scale, and operational practicality. All of the archipelago compounds and synthetic intermediates have been fully characterized spectroscopically and analytically. The solid-state structure of one archipelago model compound has been determined by X-ray crystallography.

  7. The Causality Study of External Environment Analysis (EEA), Internal Environment Analysis (IEA), Strategy Implementation on Study Program Performance at Vocational High School (VHS) in Nias Archipelago, Indonesia

    ERIC Educational Resources Information Center

    Waruwu, Binahati; Sitompul, Harun; Manullang, Belferik

    2016-01-01

    The purposes of this study are to find out the significant effect of: (1) EEA on strategy implementation, (2) IEA on strategy implementation, (3) EEA on study program performance, (4) IEA on study program performance, and (5) strategy implementation on study program performance of Vocational High School (VHS) in Nias Archipelago. The population of…

  8. Strong genetic population structure in the boring giant clam, Tridacna crocea, across the Indo-Malay Archipelago: implications related to evolutionary processes and connectivity.

    PubMed

    Kochzius, Marc; Nuryanto, Agus

    2008-09-01

    Even though the Indo-Malay Archipelago hosts the world's greatest diversity of marine species, studies on the genetic population structure and gene flow of marine organisms within this area are rather rare. Consequently, not much is known about connectivity of marine populations in the Indo-Malay Archipelago, despite the fact that such information is important to understand evolutionary and ecological processes in the centre of marine biodiversity. This study aims to investigate the genetic population structure of the boring giant clam, Tridacna crocea. The analysis is based on a 456-bp fragment of the cytochrome oxidase I gene from 300 individuals collected from 15 localities across the Indo-Malay Archipelago. Tridacna crocea shows a very strong genetic population structure and isolation by distance, indicating restricted gene flow between almost all sample sites. The observed Phi(ST)-value of 0.28 is very high compared to other studies on giant clams. According to the pronounced genetic differences, the sample sites can be divided into four groups from West to East: (i) Eastern Indian Ocean, (ii) Java Sea, (iii) South China Sea, Indonesian throughflow, as well as seas in the East of Sulawesi, and (iv) Western Pacific. This complex genetic population structure and pattern of connectivity, characterised by restricted gene flow between some sites and panmixing between others can be attributed to the geological history and prevailing current regimes in the Indo-Malay Archipelago.

  9. Consequences of climatic change, sea level rise and society evolution on the Kerkennah archipelago coast and sabkha

    NASA Astrophysics Data System (ADS)

    Lucile, Etienne; Gérard, Beltrando; Abdelkarim, Daoud

    2015-04-01

    Interaction between human activities, climate evolution and sea level can be summarised in a system where every element impacts the others. In the Kerkennah archipelago (Tunisia), recent observations have shown that the climate has become more arid, that the sea level is rising and that the society is modernizing at least since 1970. In our work we tried to understand the relations between the elements of the socio-ecosystem of Kerkennah to identify potential causes of the coastline movements and sabkhas extension (low and salty areas). Using photointerpretation (topographic map, Spot 5 image, aerial photographs) and remote sensing (2 landsat TM5 images), we detected and evaluated the movements of the coastline and of the sabkhas limits. Field data have also been added and all information has been used together in a GIS showing a significant retreat of the coastline (maximum of 41.2±6m in 47years) and an increase in the surface of sabkhas (+18%) between 1963 and 2010. The same dataset has been reanalysed at a much finer spatial scale to correlate observed changes to human pressure. This showed that coast erosion rates are more important where the coastline is partially artificialized or just after the end of a dam or a rockfill. Advances to the sea observed on some portions of the coast are always linked to human infrastructures. We conclude that the climatic change and the sea level rise increased the physical vulnerability of the archipelago and that the human installations near the coast amplify this vulnerability. Similarly, the extension of sabkha surfaces is global and most likely due to a natural perturbation of the seasonal cycle in the sabkhas by the sea level rise and by the stronger aridity in summer. However, discrepancies exist between individual areas and can be explained by the presence of active fault and/or by the evolution of agricultural practices. Indeed, frequent periods of drought and the political will for development of the Kerkennah

  10. Crustal structure beneath the Galápagos Archipelago from ambient noise tomography and its implications for plume-lithosphere interactions

    NASA Astrophysics Data System (ADS)

    Villagómez, Darwin R.; Toomey, Douglas R.; Hooft, Emilie E. E.; Solomon, Sean C.

    2011-04-01

    To constrain the seismic velocity structure of the crust beneath the Galápagos Archipelago, we conducted a tomographic study using high-frequency Rayleigh waves obtained from cross correlations of ambient noise. We analyzed waves with periods between 5 and 8.5 s, sensitive to shear wave velocity (VS) structure between about 3 and 10 km depth, after accounting for the effect of water depth. Crustal velocities are up to 25% lower than those of very young crust at the East Pacific Rise and are comparable to those of Hawaii. We attribute the lower than normal velocities to the combined effect of heating and the presence of melt in the crust above the Galápagos plume as well as the construction of a highly porous volcanic platform emplaced atop preexisting oceanic crust. On average, VS between 3 and 10 km depth beneath the western archipelago is up to 15% lower than beneath the eastern archipelago. We attribute the west-to-east velocity increase to a decrease in porosity of the volcanic platform and to cooling of the crust after its passage above the Galápagos plume. The results of this study, in combination with previous work, indicate that many of the unusual aspects of the Galápagos Archipelago are the result of variations in the thickness and internal structure of the chemical and thermal lithospheres. Our findings indicate that observed variations in the flexural response to loading observed in the Galápagos cannot be explained by the current thermal state of the lithosphere. Instead, the flexural response likely represents varying elastic strength at the time of loading. We also propose that the northwest and northeast trending alignments of volcanic centers found throughout the archipelago (the Darwinian lineations) may be associated with preexisting zones of weakness in the lithosphere formed during earlier episodes of ridge jumping and ridge propagation that were later reactivated by stresses generated by plume-lithosphere interactions.

  11. Seismicity of Barentsburg area at the Spitsbergen Archipelago: overlapping the tectonic and technogenic sources ?

    NASA Astrophysics Data System (ADS)

    Kremenetskaya, E.; Asming, V.; Vinogradov, A.

    2003-04-01

    The Western Spitsbergen Island (WSI) is located at a passive margin of the Barents shelf platform, close to the North Atlantic spreading zone marked by the Knipovich Ridge at the ocean bottom. Sublateral transform faults intersect a continental slope and provide a segmentation of uplifted over sea level block of continental crust. As a result, the Spitsbergen Archipelago is divided on small "lands" and islands by deep fiords and straights (for example, the Isfiord and Van Mijen fiord in WSI). A scope of seismic data for the last 40 years shows that earthquakes locates along the Knipovich Ridge in the ocean, and along interplate transform faults in the platform margin. In the WSI the earthquakes are concentrated in two narrow belts: Van Mijen Fiord - Heer Land and Horsund Fiord - Hamber Baystributed. A frequency of seismic events here vary of 5 to 15 ones per day, in contrast to "a quiet areas" out of the belts where the frequency use to be less in many times. The most strong earthquake with magnitude 6.0 was recorded in the Heer Land at 18 January, 1976. The Russian settlement and coal mines Barentsburg is situated within the "quiet area" of 40 km to the North from the Van Mijen seismic belt. In this area the earthquakes with local magnitude ML > 2.0 never been recorded, but underground mining operations at depth of 300-600 meters below surface associate with rock bursts. Due to evaluate a seismic hazard and clarify relationships between natural and human induced seismicity, the digital 3-component seismic station GBV 316B was installed in Barentsburg by the Kola Regional Seismological Centre (KRSC), and recording of weak seismic emission was performed in co-operation with NORSAR during a period since 01/12/2000 till 19/04/2001. Within the term a mining activity was stable till 25/03/2001, and in period from 26 March till 19 April the mines were idle. Totally of 541 seismic events were detected in the reference area 5x6 km, and only the largest one with ML of 3

  12. Paleoenvironmental reconstruction of Lake Azul (Azores archipelago, Portugal) and its implications for the NAO signal.

    NASA Astrophysics Data System (ADS)

    Jesús Rubio, Maria; Sanchez, Guiomar; Saez, Alberto; Vázquez-Loureiro, David; Bao, Roberto; José Pueyo, Juan; Gómez-Paccard, Miriam; Gonçalves, Vitor; Raposeiro, Pedro M.; Francus, Pierre; Hernández, Armand; Margalef, Olga; Buchaca, Teresa; Pla, Sergi; Barreiro-Lostres, Fernando; Valero-Garcés, Blas L.; Giralt, Santiago

    2013-04-01

    Azores archipelago lies in the southern area of the dipole that defines the North Atlantic Oscillation (NAO). During the negative phase of the NAO, the Azores high pressure is displaced southwards allowing the storms to cross the islands increasing the precipitation in this area and also in southern Europe. This fact makes them excellent key places to perform accurate high-resolution climate reconstructions. Lake Azul (37o 52' 21"N - 37o52'21"W) is a monomictic lake infilling the volcanic complex of Sete Cidades which is located in São Miguel island. This monomictic and eutrophic lake was formed around 22000 cal. years B.P. by consecutive collapses of the underneath volcanic caldera. The last eruption of the Sete Cidades crater complex was radiocarbon-dated at 500-650 cal years B.P. At present, macrophytes are restricted to the lake shore and consist mainly of Potamogeton spp., Myriophyllum alterniflorum, Ceratophyllum demersum, Nymphaea alba, and, Chara fragilis. Moreover, this crater complex has steep borders mainly covered by exotic plant species, such Cryptomeria japonica, Pittosporum undulatum and Hedychium gardnerianum. Antropogenic changes in the catchment have occurred in the last centuries including deforestation, permanent pastures (around 31%), production forest (57%) and the human settlements. In September 2011, fourteen sediment cores, up to 2.5 m long, were collected using a gravity corer from a UWITEC raft. A multiproxy characterization of these cores was carried out including smear slides, X-Ray Fluorescence, X-Ray diffraction, magnetic properties, diatom content, and bulk organic matter (d13C, d15N, TN, TOC). The chronological model was obtained by plant remains and pollen concentrates radiocarbon-dating. From base to top, three lithological units have been established from the retrieved cores: volcaniclastic rocks (lapilli), light grey laminated mud, and poor laminated light brown mud with frequent dark layers rich in plant debris. The

  13. Eruption rates at Fernandina volcano, Galapagos archipelago, from cosmogenic helium in surficial lava flows

    NASA Astrophysics Data System (ADS)

    Kurz, M. D.; Rowland, S.; Curtice, J.; Saal, A.; Naumann, T.

    2005-12-01

    Fernandina volcano is considered the center of the Galapagos hotspot because it lies at the leading (western) edge of the archipelago with respect to plate motion, has been the most active in historical times, and is characterized by extremely high 3He/4He. In an effort to determine the growth rate of the volcano, we have measured exposure ages using cosmogenic 3He measurements in olivine phenocrysts from surficially exposed lavas. Using satellite data, Rowland (1996) subdivided these flows into young, intermediate, and old, and calculated their respective surface areas, but had no method for determining ages, except for the few witnessed historical flows. The lava flows studied here span the entire exposed age range, based on both the Rowland (1996) map and field observations of weathering characteristics, vegetation, and stratigraphy. The surface exposure dates are all close to the limit of the method due to their young ages, low olivine contents in the lavas, low equatorial 3He production rates, and exposures near sea level. The oldest surfaces, found as small outcrops on the northern coast of Fernandina are therefore the most reliably dated using cosmogenic 3He, and demonstrate that the subaerial part of the volcano has been entirely resurfaced within the last 5 Ka. These data alone confirm that Fernandina has had relatively high eruption rates during that interval. The ages of the youngest flows cannot be accurately determined because cosmogenic 3He levels are below detection limits (by melting of olivine in vacuo), but they do yield useful age limits, of less than 0.8 Ka. The young flows have a surface area of 358 km2 and an approximate volume of 3.3 km3; using this volume, the minimum eruption rate of Fernandina over the last ~1 Ka has been ~0.005 km3 yr-1. This is a lower limit because the ages are upper limits, and many young flows entered the ocean. There are few eruption rates to compare for ocean island volcanoes, but this lower limit eruption rate is

  14. Geomorphological map of a coastal stretch of north-eastern Gozo (Maltese archipelago, Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Soldati, Mauro; Micallef, Anton; Biolchi, Sara; Chelli, Alessandro; Cuoghi, Alessandro; Devoto, Stefano; Gauci, Christopher; Graff, Kevin; Lolli, Federico; Mantovani, Matteo; Mastronuzzi, Giuseppe; Pisani, Luca; Prampolini, Mariacristina; Restall, Brian; Roulland, Thomas; Saliba, Michael; Selmi, Lidia; Vandelli, Vittoria

    2017-04-01

    Geomorphological investigations carried out along the north-eastern coast of the Island of Gozo (Malta) have led to the production of a detailed geomorphological map. Field surveys, accompanied by aerial photo-interpretation, were carried out within the framework of the EUR-OPA Major Hazards Agreement Project ``Developing Geomorphological mapping skills and datasets in anticipation of subsequent Susceptibility, Vulnerability, Hazard and Risk Mapping'' (Council of Europe). In particular, this geomorphological map is the main output of a `Training Course on Geomorphological Mapping in Coastal Areas' held within the Project in November 2016. The study area selected was between Ramla Bay and Dacrhlet Qorrot Bay on the Island of Gozo (67 km2), part of the Maltese archipelago in the central Mediterranean Sea. From a geological viewpoint, the stratigraphic sequence includes Late Oligocene (Chattian) to Late Miocene (Messinian) sedimentary rocks. The hard limestones of the Upper Coralline Limestone Formation, the youngest lithostratigraphic unit, dominate the study area. Underlying this formation, marls and clays belonging to the Blue Clay Formation extensively outcrop. The oldest lithostratigraphic unit observed in the study area is the Globigerina Limestone Formation, a fine-grained limestone. The lithostructural features of the outcropping units clearly condition the morphography of the landscape. The coast is characterised by the alternation of inlets and promontories. Worthy of notice is the large sandy beach of Ramla Bay partly backed by dunes. From a geomorphological perspective, the investigated coastal stretch is characterised by limestone plateaus bounded by steep structural scarps which are reshaped by gravitational and/or degradation processes, and milder slopes in Blue Clays at their foot comprising of numerous rock block deposits (rdum in Maltese) and active or abandoned terraced fields used for agricultural purposes. Landforms and processes related to

  15. Modern processes controlling the sea bed sediment formation in Barents Sea

    NASA Astrophysics Data System (ADS)

    Balanyuk, I.; Dmitrievsky, A.; Shapovalov, S.; Chaikina, O.; Akivis, T.

    2009-04-01

    The Barents Sea is one of the key regions for understanding of the postglacial history of the climate and circulation of the World Ocean. There are the limits of warm North Atlantic waters penetration to the Arctic and a zone of interaction between Atlantic and Arctic waters. The Barents Se's limits are the deep Norwegian Sea in the West, the Spitsbergen Island and the Franz Josef Land and the deep Nansen trough in the North, the Novaya Zemlya archipelago in the East and the North shore of Europe in the South. An analysis of Eurasian-Arctic continental margin shows correspondence between the rift systems of the shelf with those of the ocean. This relation can be observed in the central Arctic region. All the rift systems underlying the sediment basin are expressed in the sea bed relief as spacious and extensive graben valleys burnished by lobes. Two transverse trenches cross both shelf and continental slope, namely the Medvezhinsky trench between Norway and Spitsbergen in the West and the Franz Victoria trench between Spitsbergen and the Franz Josef Land in the North. The Barents and the Kara Seas are connected by the Kara Gate Strait and wide transverse trough of Saint Anna in the North-West. The recent assessment of the eolian solid sediment supply to the Barents Sea is about 0.904 tons. The Barents Sea as a whole should be considered as "starving" in terms of its feeding with solid sediment matter. Observations show the considerable part of the sea bottom to be free of Holocene sediment cover. The more ancient Quaternary units or bedrock can be seen at the bottom surface. This phenomenon is the most typical for arches of relatively shallow elevations. Thick accumulations of new sediments are connected with fjords. The amount of sea ice delivered from the Barents Sea to the Arctic Ocean is 35 km3 a year. This value should be added by iceberg delivery from the North island of Novaya Zemlya, the Franz Josef Land, the Spitsbergen Island and North Norway but most of

  16. Zoobotryon verticillatum Della Chiaje, 1822 (Bryozoa), a new occurrence in the archipelago of the Azores (North-Eastern Atlantic).

    PubMed

    Amat, Jaen Nieto; Tempera, Fernando

    2009-05-01

    The new occurrence of the bryozoan Zoobotryon verticillatum Della Chiaje, 1822 is herein recorded in multiple places throughout Azores archipelago. Where introduced, this species has caused important ecological and economical damage and therefore is regarded as invasive. In the Azores, no detrimental effects have yet been noted. The species is so far restricted to marinas (Horta, Faial Island; Vila Franca do Campo, São Miguel Island) and a natural coastal pool located near a secondary harbour (Lajes do Pico, Pico Island). A total of 29 colonies were counted during a specific survey conducted in August 2008 in the marina of Horta. The distribution of the species throughout the eastern and central island groups denotes a wide dispersion area and offers control or eradication measures a low probability of success together with the lack of harbour management practices that could effectively prevent the arrival, settlement and dispersal of non-native species transported by human-assisted means.

  17. Seven new species of the genus Xestoleberis (Ostracoda: Podocopida: Cytheroidea) from the Fiji Archipelago.

    PubMed

    Chand, Prerna; Kamiya, Takahiro

    2016-12-18

    The genus Xestoleberis has a global distribution, and although they are predominant in shallow marine environments adapted to both sediment and algal habitats, only two species of this genus, Xestoleberis curta (Brady, 1866) and Xestoleberis variegata Brady, 1880, have previously been reported from the Fiji archipelago. Herein we report seven new species of the genus Xestoleberis from intertidal environments of fringing reef flats of the Fiji Islands: Xestoleberis becca n. sp., Xestoleberis concava n. sp., Xestoleberis gracilariaii n. sp., Xestoleberis marcula n. sp., Xestoleberis natuvuensis n. sp., Xestoleberis penna n. sp. and Xestoleberis petrosa n. sp. With the exception of X. becca n. sp., Xestoleberis species show restricted distribution within Fijian waters. The possible causes for their distribution patterns are suggested to be physical barriers imposed by the fast flowing Bligh Water currents, and islands separated by deep ocean waters.

  18. Biology of Grapsus grapsus (L innaeus, 1758) (Brachyura, Grapsidae) in the Saint Peter and Saint Paul Archipelago, Equatorial Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Freire, A. S.; Pinheiro, M. A. A.; Karam-Silva, H.; Teschima, M. M.

    2011-09-01

    Eleven expeditions were undertaken to the Saint Peter and Saint Paul Archipelago to study the reproductive biology of Grapsus grapsus, providing additional information on limb mutilation and carapace colour. MATURE software was used to estimate morphological maturity, while gonadal analyses were conducted to estimate physiological maturity. The puberty moult took place at larger size in males (51.4 mm of carapace length) than in females (33.8 mm), while physiological maturity occurred at a similar size in males (38.4 mm) and in females (33.4 mm). Above 50 mm, the proportion of red males increased in the population, indicating that functional maturity is also related to colour pattern. Small habitat and high local population density contributed to the high rate of cannibalism. The low diversity of food items, absence of predators of large crabs and high geographic isolation are the determinants of unique behavioural and biological characteristics observed in the G. grapsus population.

  19. Map of glacial limits and possible refugia in the southern Alexander Archipelago, Alaska, during the late Wisconsin glaciation

    USGS Publications Warehouse

    Carrara, Paul E.; Ager, Thomas A.; Baichtal, James F.; VanSistine, D. Paco

    2003-01-01

    During the late Wisconsin glaciation (circa 26,000-13,000 carbon-14 yr BP) the Cordilleran glacier complex formed vast ice fields and large glaciers along the crest of the Coast Mountains. As these glaciers flowed west to the Pacific Ocean, they were joined by local glaciers originating on the higher reaches of the Alexander Archipelago (Mann and Hamiltion, 1995). This extensive volume of ice was channeled into deep troughs (present-day fiords) that formed major outlet glaciers, such as the glaciers that occupied Chatham Strait and Dixon Entrance. In several places along the coast, deep glacially scoured submarine troughs indicate that glaciers reached to the edge of the continental shelf. For instance, the glacier that extended into the Dixon Entrance trough is known to have extended to the edge of the continental shelf. Its retreat began sometime after 16,000-15,000 carbon-14 yr BP (Barrie and Conway, 1999).

  20. Karyological study of Amphisbaena ridleyi (Squamata, Amphisbaenidae), an endemic species of the Archipelago of Fernando de Noronha, Pernambuco, Brazil

    PubMed Central

    2010-01-01

    The karyotype of Amphisbaena ridleyi, an endemic species of the archipelago of Fernando de Noronha, in State of Pernambuco, Brazil, is described after conventional staining, Ag-NOR impregnation and fluorescence in situ hybridization (FISH) with a telomeric probe. The diploid number is 46, with nine pairs of macrochromosomes (three metacentrics, four subtelocentrics and two acrocentrics) and 14 pairs of microchromosomes. The Ag-NOR is located in the telomeric region of the long arm of metacentric chromosome 2 and FISH revealed signals only in the telomeric region of all chromosomes. Further cytogenetic data on other amphisbaenians as well as a robust phylogenetic hypothesis of this clade is needed in order to understand the evolutionary changes on amphisbaenian karyotypes. PMID:21637605

  1. Karyological study of Amphisbaena ridleyi (Squamata, Amphisbaenidae), an endemic species of the Archipelago of Fernando de Noronha, Pernambuco, Brazil.

    PubMed

    Laguna, Marcia Maria; Amaro, Renata Cecília; Mott, Tamí; Yonenaga-Yassuda, Yatiyo; Rodrigues, Miguel Trefaut

    2010-01-01

    The karyotype of Amphisbaena ridleyi, an endemic species of the archipelago of Fernando de Noronha, in State of Pernambuco, Brazil, is described after conventional staining, Ag-NOR impregnation and fluorescence in situ hybridization (FISH) with a telomeric probe. The diploid number is 46, with nine pairs of macrochromosomes (three metacentrics, four subtelocentrics and two acrocentrics) and 14 pairs of microchromosomes. The Ag-NOR is located in the telomeric region of the long arm of metacentric chromosome 2 and FISH revealed signals only in the telomeric region of all chromosomes. Further cytogenetic data on other amphisbaenians as well as a robust phylogenetic hypothesis of this clade is needed in order to understand the evolutionary changes on amphisbaenian karyotypes.

  2. Development and characterization of EST-SSR markers for the Solidago virgaurea complex (Asteraceae) in the Japanese archipelago1

    PubMed Central

    Sakaguchi, Shota; Ito, Motomi

    2014-01-01

    • Premise of the study: We developed simple sequence repeat (SSR) markers from expressed sequence tags (ESTs) for the Solidago virgaurea complex, an ecologically and morphologically diverse species complex in the Japanese archipelago, to elucidate population genetic structure and examine taxonomic boundaries. • Methods and Results: Utilizing the RNA sequencing data obtained by next-generation sequencing techniques, 15 polymorphic EST-SSR markers with three to 14 alleles were developed, most of which were transferable to different Solidago species native to Eurasia and North America. • Conclusions: The EST-SSR markers developed in this study may be useful for elucidating the population structure and taxonomic delimitation of the species complex, as well as for investigating the population genetics and reproductive ecology of Solidago species. PMID:25202641

  3. Development and characterization of EST-SSR markers for the Solidago virgaurea complex (Asteraceae) in the Japanese archipelago.

    PubMed

    Sakaguchi, Shota; Ito, Motomi

    2014-07-01

    We developed simple sequence repeat (SSR) markers from expressed sequence tags (ESTs) for the Solidago virgaurea complex, an ecologically and morphologically diverse species complex in the Japanese archipelago, to elucidate population genetic structure and examine taxonomic boundaries. • Utilizing the RNA sequencing data obtained by next-generation sequencing techniques, 15 polymorphic EST-SSR markers with three to 14 alleles were developed, most of which were transferable to different Solidago species native to Eurasia and North America. • The EST-SSR markers developed in this study may be useful for elucidating the population structure and taxonomic delimitation of the species complex, as well as for investigating the population genetics and reproductive ecology of Solidago species.

  4. Brachiopods from off the San Bernardo Archipelago (Colombian Caribbean), with comments on specific synonymies in Tichosina Cooper, 1977.

    PubMed

    Rojas, Alexis; Gracia, Adriana; Patarroyo, Pedro

    2015-01-23

    Colombian brachiopod faunas have not been studied extensively. Only three brachiopod species have been reported from the Colombian Caribbean Sea so far, namely Argyrotheca barrettiana (Davidson, 1866), Terebratulina latifrons Dall, 1920, and the cosmopolitan Platidia anomioides (Scacchi & Philippi, 1844). In this work, brachiopods collected from deep-water environments (90-250 m) off the San Bernardo Archipelago, collected during the MARCORAL cruise, are examined. The studied material consists of four species, two of which are new records for Colombia: Terebratulina cailleti Crosse, 1865 and Tichosina plicata Cooper, 1977. The genus Tichosina belongs to the family Terebratulidae and comprises twenty extant species occurring across the Caribbean. Based on a revision of published descriptions and illustrations, we synonymize Tichosina bullisi Cooper, 1977 and Tichosina dubia Cooper, 1977 with Tichosina plicata Cooper, 1977. Remarkably, apart from reports from southern Guiana, T. plicata is restricted to the margins of the Caribbean plate. 

  5. Plastic litter in sediments from a marine area likely to become protected (Aeolian Archipelago's islands, Tyrrhenian sea).

    PubMed

    Fastelli, Paolo; Blašković, Andrea; Bernardi, Giulia; Romeo, Teresa; Čižmek, Hrvoje; Andaloro, Franco; Russo, Giovanni F; Guerranti, Cristiana; Renzi, Monia

    2016-12-15

    This research aims to define for the first time levels and patterns of different litter groups (macro, meso and microplastics) in sediments from a marine area designed for the institution of a new marine protected area (Aeolian Archipelago, Italy). Microplastics resulted the principal group and found in all samples analyzed, with shape and colours variable between different sampling sites. MPs levels measured in this study are similar to values recorded in harbour sites and lower than reported in Adriatic Sea, while macroplastics levels are notably lower than in harbor sites. Sediment grain-size and island extent resulted not significant in determining levels and distribution of plastic debris among islands. In the future, following the establishment of the MPA in the study area, these basic data will be useful to check for potential protective effects on the levels and distribution of plastic debris.

  6. Distribution and bioavailability of cadmium in ornithogenic coral-sand sediments of the Xisha archipelago, South China Sea.

    PubMed

    Liu, Xiaodong; Lou, Chuangneng; Xu, Liqiang; Sun, Liguang

    2012-09-01

    Total cadmium (Cd) concentrations in four ornithogenic coral-sand sedimentary profiles displayed a strong positive correlation with guano-derived phosphorus, but had no correlation with plant-originated organic matter in the top sediments. These results indicate that the total Cd distributions were predominantly controlled by guano input. Bioavailable Cd and zinc (Zn) had a greater input rate in the top sediments with respect to total Cd and total Zn, and a positive correlation with total organic carbon (TOC) derived from plant humus. Multi-regression analysis showed that the total Cd and TOC explained over 80% of the variation of bioavailable Cd, suggesting that both guano and plant inputs could significantly influence the distribution of bioavailable Cd, and that plant biocycling processes contribute more to the recent increase of bioavailable Cd. A pollution assessment indicates that the Yongle archipelago is moderately to strongly polluted with guano-derived Cd. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. One-century decline of mollusk diversity as consequence of accumulative anthropogenic disturbance in a tropical estuary (Cuban Archipelago).

    PubMed

    Armenteros, Maickel; Díaz-Asencio, Misael; Fernández-Garcés, Raúl; Hernández, Carlos Alonso; Helguera-Pedraza, Yusmila; Bolaños-Alvarez, Yoelvis; Agraz-Hernández, Claudia; Sanchez-Cabeza, Joan-Albert

    2016-12-15

    In order to infer changes in sediments and mollusk assemblages for the last century, we used biogeochemical data from two (210)Pb dated cores collected in Sagua La Grande estuary, Cuban Archipelago. We found evidences of cumulative anthropogenic disturbance during the last century, causing considerable depletion of mollusk assemblage diversity and enhancement of the dominance of deposit feeding species. The sequence of impacts assessed was i) eutrophication due to nutrient releases from urban settlements, ii) habitat alteration due to water channeling and damming, and iii) mercury pollution. These successive impacts caused a steady diversity depletion from ca. 70 mollusk species in 1900 to less than five in 2010. Only two species persisted in the estuary: Nuculana acuta and Finella dubia. Hurricanes did not impact the molluscan fauna in the long term. The effects of the anthropogenic impacts suggest that the resilience of this estuarine system is compromised. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Two new genera of the pharyngodonidae (Nematoda: Oxyuroidea) found in rhacophorid frogs of the Ryukyu Archipelago, Japan.

    PubMed

    Hasegawa, Hideo

    2005-02-01

    Okinawandros goldbergi n. gen., n. sp. and Ataronema sekii n. gen., n. sp. (Nematoda: Pharyngodonidae) are described from rhacophorid frogs of the Ryukyu Archipelago, Japan. Okinawandros n. gen. resembles Batracholandros Freitas et Ibañez, 1965 and Synodontisia Petter, Vassiliades et Troncy, 1972 but is readily distinguished from the former in lacking laterally situated genital papillae and by having anteriorly directed vagina and from the latter by having operculated eggs and lacking a spicule. Ataronema n. gen. most closely resembles Parathelandros Baylis, 1930 but is readily distinguished because the posterior pair of caudal papillae is not rosette shaped and the eggs are not operculated. Morphological notes of Pharyngodon polypedatis Yamaguti, 1941 are included.

  9. A new genus and species of hatschekiid copepod (Siphonostomatoida) from groupers (Actinopterygii: Serranidae) collected off the Ryukyu Archipelago, Japan.

    PubMed

    Uyeno, Daisuke

    2013-01-01

    A new genus and species of copepod, Mihbaicola sakamakii n. g., n. sp., belonging to the siphonostomatoid family Hatschekiidae, is described based on the females collected from inside the tissue of the branchiostegal membrane in three species of the groupers, Epinephelus fasciatus (Forsskål) (type-host), E. merra Bloch and Cephalopholis leopardus (Lacépède), collected off Okinawa-jima Island and Iriomote-jima Island, Ryukyu Archipelago, North Pacific Ocean. The new genus can be distinguished from other hatschekiid genera by a combination of the following characters in the female: the head is composed of the cephalosome and the pedigerous somite; the cephalothorax is expanded into a pair of posteroventral lobes carrying leg 1; legs 1 and 2 are biramous and composed of the protopod and both rami are 2-segmented; leg 3 is absent; and leg 4 is represented by a rounded lobe with a chitinous pointed apical process.

  10. A new species of Plestiodon (Squamata: Scincidae) from the Senkaku Group, Ryukyu Archipelago, Japan.