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Sample records for gull island shoal

  1. Population recovery and natural recruitment of lake trout at Gull Island Shoal, Lake Superior, 1964-1992

    USGS Publications Warehouse

    Schram, Stephen T.; Selgeby, James H.; Bronte, Charles R.; Swanson, Bruce L.

    1995-01-01

    We documented an increase in the abundance of wild lake trout (Salvelinus namaycush) at Gull Island Shoal in western Lake Superior and examined the relationship between parental-stock size and recruitment of age-0 fish in 1964–1992. Abundance of adult wild female lake trout and densities of age-0 fish both increased during the 28-year period. A significant positive, linear relationship (P = 0.0002) was found between the abundance of wild females on the spawning reef in the fall and density of age-0 lake trout on adjacent nursery grounds in August and September of the following year. The abundance of hatchery-origin females did not explain significant amounts (P = 0.107) of variation in recruitment. We concluded that most recruitment in 1965–1992 was the result of natural reproduction of wild females. After 28 years of recovery the Gull Island Shoal lake trout population appears to have additional capacity to increase because the stock-recruitment relationship is still linear. Therefore, restoration periods on the order of 30 years may be needed for other lake trout populations in the Great Lakes. We recommend that the refuge established to protect this population be maintained to allow further study of the relationship between parental stock and recruitment, and to provide a major source of recruitment to the lake trout population in the surrounding waters

  2. Hatching, dispersal, and bathymetric distribution of age-0 wild lake trout at the Gull Island Shoal complex, Lake Superior

    USGS Publications Warehouse

    Bronte, Charles R.; Selgeby, James H.; Saylor, James H.; Miller, Gerald S.; Foster, Neal R.

    1995-01-01

    We studied age-0 lake trout (Salvelinus namaycush) associated with spawning and nursery areas of the Gull Island Shoal complex in western Lake Superior. Post-emergent age-0 lake trout were captured on rocky spawning substrate with a 3-m beam trawl and at the nursery area with a bottom trawl from June to September 1990 and June to August 1991. Catch data suggested that age-0 lake trout move distances of 7–11 km to the nursery area over a 3-month period. Water currents, measured at Gull Island Shoal, may be a part of the transport mechanism. Examination of daily-growth increments on the sagittae and back-calculation from the date of capture revealed that most fish hatched between 6 June and 19 July in 1990 and between 30 April and 30 May in 1991. The duration of the hatch was 100 days in 1990 and 120 days in 1991, and the estimated incubation period is about 7 months for lake trout eggs at this site. Similar hatch-date distributions of age-0 captured on different sampling dates suggested that natural mortality was low.

  3. Effects of herring gulls and great black-backed gulls on breeding piping plovers, South Monomoy Island, Massachusetts. Final Report

    USGS Publications Warehouse

    Keane, S.E.; Fraser, J.D.; Buckley, P.A.

    2002-01-01

    The large population of breeding herring gulls and great black-backed gulls on South Monomoy Island, Cape Cod, Massachusetts has been thought to negatively affect the breeding success of the threatened piping plover. Following the Piping Plover Recovery Plan's call for gull colonies to be removed from piping plover breeding sites, in 1996, the USFWS conducted gull removal on part of South Monomoy Island. We determined relative gull abundance on South Monomoy Island from 1998-2000 by counting gulls within 100-m radius plots located on the shoreline. We quantified piping plover behavior and habitat use by conducting instantaneous and 5-minute behavioral observations. We quantified characteristics of piping plover nesting habitat by measuring characteristics along random transects. We measured gull abundance, beach width, and prey abundance, and then used logistic regression to determine what habitat characteristics influenced piping plover nesting area selection. We monitored piping plover reproductive success and population fluctuations on South Monomoy Island. Gull abundance in the gull-removal area was lower than gull abundance in the reference area throughout the piping plover breeding season. The difference in gull abundance between the areas did not affect piping plover behavior, nest success, chick survival, or productivity. We found that gull removal did not result in an increased piping plover population on the island. In both management areas, prenesting plovers preferred to forage in moist substrate habitats. Wide backshore and open vegetation habitats characterized nesting areas. Broods spent most of their time foraging and preferred moist substrate habitats when available. Plovers were not prevented from occupying more suitable habitat by large gulls. Fewer large gulls were observed near prenesting plovers, plover nests, and plover broods than near random plots. Fewer large gulls were observed in plover nesting areas than in unused areas when the nesting

  4. Mapping islands, reefs and shoals in the oceans surrounding Australia

    NASA Technical Reports Server (NTRS)

    Turner, L. G. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. Comparisons of the imagery with aerial photography of areas of reefs and island and with 1:250,000 maps of coastlines indicate that the MSS imagery depicts detail to an extent which is satisfactory for 1:250,000 mapping. As the imagery does not have some of the disadvantages of aerial photography, the former should be valuable for mapping reefs, islands, and shoals. The water discoloration problem is significant as the discolored water appears to occur near shallow depths, so that confusion could arise through the misinterpretation of discolored water, when it exists, as shallow water.

  5. Character of shell beds flanking Herod Point shoal, southeastern Long Island Sound, New York

    USGS Publications Warehouse

    Poppe, L.J.; Williams, S.J.; Babb, Ivar G.

    2011-01-01

    High biogenic productivity, strong tidal currents, shoal topography, and short transport distances combine to favor shell-bed formation along the lower flanks of a cape-associated shoal off Herod Point on Long Island, New York. This shell bed has a densely packed, clast-supported fabric composed largely of undegraded surf clam (Spisula solidissima) valves. It is widest along the central part of the western flank of the shoal where topographic gradients are steep and a stronger flood tide results in residual flow. The bed is narrower and thinner toward the landward margins where currents are too weak to transport larger valves and topographic gradients are gentle, limiting bed-load transport mechanisms by which the shells are concentrated. Reconnaissance mapping off Roanoke Point suggests that shell beds are also present at the other cape-associated shoals off northeastern Long Island, where relatively similar geomorphic and oceanographic conditions exist. These shell beds are important to the Long Island Sound ecosystem because they provide complex benthic habitats of rough and hard substrates at the boundary between the muddy basin floor and mobile sand of the shoals. ?? 2011, the Coastal Education & Research Foundation (CERF).

  6. 33 CFR 334.40 - Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area. 334.40 Section 334.40... AND RESTRICTED AREA REGULATIONS § 334.40 Atlantic Ocean in vicinity of Duck Island, Maine, Isles...

  7. 33 CFR 334.40 - Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area. 334.40 Section 334.40... AND RESTRICTED AREA REGULATIONS § 334.40 Atlantic Ocean in vicinity of Duck Island, Maine, Isles...

  8. 33 CFR 334.40 - Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area. 334.40 Section 334.40... AND RESTRICTED AREA REGULATIONS § 334.40 Atlantic Ocean in vicinity of Duck Island, Maine, Isles...

  9. 33 CFR 334.40 - Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area. 334.40 Section 334.40... AND RESTRICTED AREA REGULATIONS § 334.40 Atlantic Ocean in vicinity of Duck Island, Maine, Isles...

  10. 33 CFR 334.40 - Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area. 334.40 Section 334.40... AND RESTRICTED AREA REGULATIONS § 334.40 Atlantic Ocean in vicinity of Duck Island, Maine, Isles...

  11. High prevalence of Salmonella and IMP-4-producing Enterobacteriaceae in the silver gull on Five Islands, Australia

    PubMed Central

    Dolejska, Monika; Masarikova, Martina; Dobiasova, Hana; Jamborova, Ivana; Karpiskova, Renata; Havlicek, Martin; Carlile, Nicholas; Priddel, David; Cizek, Alois; Literak, Ivan

    2016-01-01

    Objectives The objective of this study was to investigate the silver gull as an indicator of environmental contamination by salmonellae and carbapenemase-producing Enterobacteriaceae (CPE) in south-east Australia. Methods A total of 504 cloacal samples were collected from gull chicks at three nesting colonies in New South Wales, Australia [White Bay (n = 144), Five Islands (n = 200) and Montague Island (n = 160)] and were examined for salmonellae and CPE. Isolates were tested for carbapenemase genes and susceptibility to 14 antibiotics. Clonality was determined by PFGE and MLST. Genetic context and conjugative transfer of the carbapenemase gene were determined. Results A total of 120 CPE of 10 species, mainly Escherichia coli (n = 85), carrying the gene blaIMP-4, blaIMP-38 or blaIMP-26 were obtained from 80 (40%) gulls from Five Islands. Thirty percent of birds from this colony were colonized by salmonellae. Most isolates contained the gene within a class 1 integron showing a blaIMP-4-qacG-aacA4-catB3 array. The blaIMP gene was carried by conjugative plasmids of variable sizes (80–400 kb) and diverse replicons, including HI2-N (n = 30), HI2 (11), A/C (17), A/C-Y (2), L/M (5), I1 (1) and non-typeable (6). Despite the overall high genetic variability, common clones and plasmid types were shared by different birds and bacterial isolates, respectively. Conclusions Our data demonstrate a large-scale transmission of carbapenemase-producing bacteria into wildlife, likely as a result of the feeding habits of the birds at a local waste depot. The isolates from gulls showed significant similarities with clinical isolates from Australia, suggesting the human origin of the isolates. The sources of CPE for gulls on Five Islands should be explored and proper measures applied to stop the transmission into the environment. PMID:26472769

  12. Offshore sand-shoal development and evolution of Petit Bois Pass, Mississippi-Alabama Barrier Islands, Mississippi, USA

    USGS Publications Warehouse

    Flocks, James G.; Kelso, Kyle W.; Twichell, Gregory C.; Buster, Noreen A.; Baehr, John N.

    2011-01-01

    Assessment of recently collected geophysical and sediment-core data identifies an extensive shoal field located off Dauphin and Petit Bois Islands. The shoals are the product of Pleistocene fluvial deposition and Holocene marine-transgressive processes, and their position and orientation oblique to the modern shoreline has been stable over the past century. The underlying stratigraphy has also influenced the evolution of the barrier platform and inlets. Buried distributary channels bisect the platform, creating erosion hotspots that breach during intense and repeated storms. Inlet growth inhibits littoral transport, and over time, reduces the down-drift sand supply. These relations demonstrate the role of the antecedent geologic framework on morphologic evolution. This study is part of the USGS Northern Gulf of Mexico Ecosystem Change and Hazard Susceptibility Project and the USACE Mississippi Coastal Improvements Program. These projects produced a wealth of information regarding coastal geology, geomorphology, and physical resources; some of the initial results are presented here.

  13. Factors affecting marine debris deposition at French Frigate Shoals, Northwestern Hawaiian Islands Marine National Monument, 1990-2006.

    PubMed

    Morishige, Carey; Donohue, Mary J; Flint, Elizabeth; Swenson, Christopher; Woolaway, Christine

    2007-08-01

    Data on the amount and type of small debris items deposited on the beaches of the Hawaiian Islands National Wildlife Refuge Tern Island station, French Frigate Shoals were collected over 16 years. We calculated deposition rates and investigated the relationship among deposition and year, season, El Niño and La Niña events from 1990 to 2006. In total 52,442 debris items were collected with plastic comprising 71% of all items collected. Annual debris deposition varied significantly (range 1116-5195 items) but was not influenced by season. Debris deposition was significantly greater during El Niño events as compared to La Niña events. Although often deduced to influence floating marine pollution, this study provides the first quantitative evidence of the influence of El Niño/La Niña cycles on marine debris deposition. PMID:17572447

  14. Analysis of seafloor change at Breton Island, Gosier Shoals, and surrounding waters, 1869–2014, Breton National Wildlife Refuge, Louisiana

    USGS Publications Warehouse

    Flocks, James G.; Terrano, Joseph F.

    2016-01-01

    Characterizing bathymetric change in coastal environments is an important component in understanding shoreline evolution, especially along barrier island platforms. Bathymetric change is a function of the regional sediment budget, long-term wave and current patterns, and episodic impact from high-energy events such as storms. Human modifications may also cause changes in seafloor elevation. This study, conducted by the U.S. Geological Survey in collaboration with the U.S. Fish and Wildlife Service, evaluates bathymetric and volumetric change and sediment characteristics around Breton Island and Gosier Shoals located offshore of the Mississippi River Delta in Louisiana. This area has been affected by significant storm events such as Hurricane Katrina in 2005. Sedimentation patterns at Breton Island and offshore have also been modified by the excavation of a shipping channel north of the island. Four time periods are considered that encompass these episodes and include long-term change and short-term storm recovery: 1869–2014, 1869–1920, 1920–2014, and 2007–2014. Finally, sediment characteristics are reported in the context of seafloor elevation.

  15. Hepatic cytochrome P450 activity and pollutant concentrations in paradise shelducks and southern black-backed gulls in the South Island of New Zealand.

    PubMed

    Numata, Mihoko; Fawcett, J Paul; Saville, Dorothy J; Rosengren, Rhonda J

    2008-11-01

    Cytochrome P450 (CYP) enzymes catalyse the oxidative metabolism of various xenobiotics including environmental pollutants. We investigated liver microsomal CYP marker activities in 60 paradise shelducks (Tadorna variegata; herbivore) and 77 southern black-backed gulls (Larus dominicanus; omnivore) collected at three sites with putatively different levels of pollution in the South Island of New Zealand. Ethoxyresorufin O-deethylase (EROD) activity was high in birds at an urban landfill site compared to those at a relatively pristine and an agricultural site. Analysis of p-nitrophenol hydroxylase and erythromycin demethylase activities indicated the presence of two additional CYP isoforms in shelducks but no additional form in gulls. Total polychlorinated biphenyl (PCB) concentrations (ranges: shelducks, 0.073-6.2; gulls, 8.2-330 ng/g wet weight) were high in landfill samples suggesting a link to EROD induction and, in landfill shelducks, EROD was independently associated with Hg and Pb concentration. PCB congener-specific assessments indicated the metabolism of at least two congeners (#28 and #74) is induced in shelducks. DDE concentrations (ranges: shelducks, 0.85-320; gulls, 44-4800 ng/g) were high in birds at the landfill and agricultural sites. Body weight tended to be lower in landfill birds, but whether this reflects the greater energetic demands of pollutant detoxification remains to be investigated. PMID:18473165

  16. New and poorly known species of Bairdoppilata and Paranesidea (Bairdiidae, Ostracoda) from French Frigate Shoals and O'ahu, the Hawaiian Islands.

    PubMed

    Maddocks, Rosalie F

    2015-01-01

    Bairdoppilata scaura, n. sp. and five species of Bairdoppilata and Paranesidea in open nomenclature are described from encrusting communities on French Frigate Shoals and Kane'ohe Bay, Oahu, Hawaiian Islands. Some poorly documented anatomical traits (carapace setae, hingement, antennal claws, genitalia) are examined for their potential taxonomic significance, in order to confirm the coherence of the Genus Bairdoppilata and to explore its diversity. PMID:26701564

  17. Hydroacoustic estimation of zooplankton biomass at two shoal complexes in the Apostle Islands Region of Lake Superior

    USGS Publications Warehouse

    Holbrook, B.V.; Hrabik, T.R.; Branstrator, D.K.; Yule, D.L.; Stockwell, J.D.

    2006-01-01

    Hydroacoustics can be used to assess zooplankton populations, however, backscatter must be scaled to be biologically meaningful. In this study, we used a general model to correlate site-specific hydroacoustic backscatter with zooplankton dry weight biomass estimated from net tows. The relationship between zooplankton dry weight and backscatter was significant (p < 0.001) and explained 76% of the variability in the dry weight data. We applied this regression to hydroacoustic data collected monthly in 2003 and 2004 at two shoals in the Apostle Island Region of Lake Superior. After applying the regression model to convert hydroacoustic backscatter to zooplankton dry weight biomass, we used geostatistics to analyze the mean and variance, and ordinary kriging to create spatial zooplankton distribution maps. The mean zooplankton dry weight biomass estimates from plankton net tows and hydroacoustics were not significantly different (p = 0.19) but the hydroacoustic data had a significantly lower coefficient of variation (p < 0.001). The maps of zooplankton distribution illustrated spatial trends in zooplankton dry weight biomass that were not discernable from the overall means.

  18. Geology of Saipan, Mariana Islands; Part 4, Submarine topography and shoal-water ecology

    USGS Publications Warehouse

    Cloud, Preston E., Jr.

    1959-01-01

    The topography of the sea floor within 10 miles of Saipan broadly resembles that of the land. Eastward, toward the Mariana trench, slopes are about 6°, without prominent benches or scarps. This is inferred to indicate easterly continuation of generally pyroclastic bedrock. The westward slope averages 2° to 3° and consists mainly of nearly flat benches and westfacing scarps. This is taken to imply westward continuation of a limestone bench-and-fault-scarp topography. Projection of known faults to sea and through Tinian, on the basis of topographic trends, suggests a pattern of west-dipping normal faults that parallel the strike of the Mariana ridge and affect the shape and position of islands at the crest of the ridge.

  19. Activity periods and questing behavior of the seabird tick Ixodes uriae (Acari: Ixodidae) on Gull Island, Newfoundland: the role of puffin chicks.

    PubMed

    Muzaffar, Sabir B; Jones, Ian L

    2007-04-01

    Questing behavior of Ixodes uriae and their associated seasonal, host-feeding patterns are crucial to our understanding of tick life history strategies and the ecology of diseases that they transmit. Consequently, we quantified questing behavior of nymphs and adult female I. uriae ticks at Gull Island, a seabird colony in Newfoundland, Canada, to examine seasonal variation of off-host and on-host tick activity. We sampled a total of 133 adult Atlantic puffins (Fratercula arctica), 152 puffin chicks, and 145 herring gull (Larus argentatus) chicks for ticks during the breeding seasons of 2004 and 2005. Questing ticks were sampled by dragging a white flannel cloth across the grassy breeding areas during the mo of May, June, July, and August. Nymph questing activity reached a peak during mid-July (79 and 110 individuals/hr in 2004 and 2005, respectively). The prevalence of nymphs and adult female ticks on different seabird hosts varied between years and during the seasons. Puffin chicks had the highest prevalence (above 70% in July) of nymphs in both years and this was correlated with questing activity. Female ticks rarely fed on puffin chicks, but were prevalent on adult puffins and gulls, although prevalence and questing of ticks were not correlated in these hosts. These patterns of off-host and on-host tick activity suggests that I. uriae ticks likely use a combination of questing and passive waiting, e.g., in puffin burrows, to detect hosts, depending on the tick stage and the host species. PMID:17539407

  20. Aerial estimation of the size of gull breeding colonies

    USGS Publications Warehouse

    Kadlec, J.A.; Drury, W.H.

    1968-01-01

    Counts on photographs and visual estimates of the numbers of territorial gulls are usually reliable indicators of the number of gull nests, but single visual estimates are not adequate to measure the number of nests in individual colonies. To properly interpret gull counts requires that several islands with known numbers of nests be photographed to establish the ratio of gulls to nests applicable for a given local census. Visual estimates are adequate to determine total breeding gull numbers by regions. Neither visual estimates nor photography will reliably detect annual changes of less than about 2.5 percent.

  1. Phosphorus in seagull colonies and the effect on the habitats. The case of yellow-legged gulls (Larus michahellis) in the Atlantic Islands National Park (Galicia-NW Spain).

    PubMed

    Otero, X L; Tejada, O; Martín-Pastor, M; De La Peña, S; Ferreira, T O; Pérez-Alberti, A

    2015-11-01

    During the period 1980-2000, the yellow-legged gull population underwent exponential growth due to an increase in the availability of anthropogenic food resources. The aim of this study was to highlight the effect of the gull colonies on the P soil cycle and the associated effects on coastal ecosystems. Samples of soil, water and faecal material were collected in a colony of yellow-legged gulls (Cíes Islands) and in a control area. Four sampling plots were installed in the study areas, and samples were collected in summer and winter in 1997 and 2011. Sample analysis included soil characterization and determination of the total P content (TP), bioavailable-P and fractionated-P forms in the soils and faecal material. The (31)P NMR technique was also used to determine organic P forms. Clear differences between the gull colony soils and the control soil were observed. The TP was 3 times higher in the gull colony soil, and the bioavailable P was 30 times higher than in the control soil. The P forms present at highest concentrations in the faecal material (P-apatite, P-residual and P-humic acid) were also present at high concentrations in the colony soil. The absence of any seasonal or annual differences in P concentration indicates that the P has remained stable in the soil over time, regardless of the changes in the gull population density. The degree of P saturation indicated that soils are saturated with P due to the low concentration of Fe/Al-hydroxides, which is consistent with a high P concentration in the run-off from the colonies. The P output from the colony soils to coastal waters may cause eutrophication of a nearby lagoon and the disappearance of a Zostera marina seagrass meadow. Similarly, the enrichment of P concentration in dune system of Muxieiro may induce irreversible changes in the plant communities. PMID:26081740

  2. Spatial heterogeneity of benthic community assemblages with an emphasis on reef algae at French Frigate Shoals, Northwestern Hawai`ian Islands

    NASA Astrophysics Data System (ADS)

    Vroom, Peter S.; Page, Kimberly N.; Peyton, Kimberly A.; Kukea-Shultz, J. Kanekoa

    2005-12-01

    Reefs in tropical atoll systems have historically been described on a geomorphic basis, and segregated into loosely defined fore-reef, back-reef, and lagoonal reef zones. However, recent oceanographic monitoring data have shown that physical factors within a single geomorphic zone can vary significantly, calling into question whether benthic communities within a single zone are biologically similar. To determine the amount of benthic variability that may occur in a geomorphic zone, percent cover of benthic organisms was determined at the species level for 28 sites in three geomorphic zones at French Frigate Shoals, Northwestern Hawai‘ian Islands. Multivariate statistical analyses found most windward fore-reef and back-reef sites to be statistically similar, but considerable variation to exist among sites within calmer lagoonal areas. Surveys revealed macroalgae to dominate over scleractinian coral species at the majority of sites in this healthy, subtropical reef system, although select lagoonal areas were dominated by dense coral communities.

  3. Effects of oil transferred from incubating gulls to their eggs

    USGS Publications Warehouse

    King, K.A.; LeFever, C.A.

    1979-01-01

    No. 2 fuel oil, or water, was applied to the breast feathers of incubating laughing gulls trapped at their nest site on an island colony in Texas. Gulls were released after treatment and allowed to incubate their eggs for 5 days. Oil was transferred from the feathers of incubating adults to their eggs and resulted in 41% embryo mortality compared with 2% in controls.

  4. 15. Photo copy of drawing, May, 3, 1963. STRATFORD SHOAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Photo copy of drawing, May, 3, 1963. STRATFORD SHOAL L/S FIRE DETECTION AND FIRE EXTINGUISHING SYSTEMS. Drawing no. 03-2723, U.S. Coast Guard Civil Engineering Unit, Warwick, Rhode Island. - Stratford Shoal Lighthouse, Long Island Sound, Bridgeport, Fairfield County, CT

  5. Ship Shoal as a prospective borrow site for barrier island restoration, coastal south-central Louisiana, Usa: Numerical wave modeling and field measurements of hydrodynamics and sediment transport

    USGS Publications Warehouse

    Stone, G.W.; Pepper, D.A.; Xu, Jie; Zhang, X.

    2004-01-01

    Ship Shoal, a transgressive sand body located at the 10 m isobath off south-central Louisiana, is deemed a potential sand source for restoration along the rapidly eroding Isles Dernieres barrier chain and possibly other sites in Louisiana. Through numerical wave modeling we evaluate the potential response of mining Ship Shoal on the wave field. During severe and strong storms, waves break seaward of the western flank of Ship Shoal. Therefore, removal of Ship Shoal (approximately 1.1 billion m3) causes a maximum increase of the significant wave height by 90%-100% and 40%-50% over the shoal and directly adjacent to the lee of the complex for two strong storm scenarios. During weak storms and fair weather conditions, waves do not break over Ship Shoal. The degree of increase in significant wave height due to shoal removal is considerably smaller, only 10%-20% on the west part of the shoal. Within the context of increasing nearshore wave energy levels, removal of the shoal is not significant enough to cause increased erosion along the Isles Dernieres. Wave approach direction exerts significant control on the wave climate leeward of Ship Shoal for stronger storms, but not weak storms or fairweather. Instrumentation deployed at the shoal allowed comparison of measured wave heights with numerically derived wave heights using STWAVE. Correlation coefficients are high in virtually all comparisons indicating the capability of the model to simulate wave behavior satisfactorily at the shoal. Directional waves, currents and sediment transport were measured during winter storms associated with frontal passages using three bottom-mounted arrays deployed on the seaward and landward sides of Ship Shoal (November, 1998-January, 1999). Episodic increases in wave height, mean and oscillatory current speed, shear velocity, and sediment transport rates, associated with recurrent cold front passages, were measured. Dissipation mechanisms included both breaking and bottom friction due to

  6. Effects of introducing foxes and raccoons on herring gull colonies

    USGS Publications Warehouse

    Kadlec, J.A.

    1971-01-01

    Red foxes (Vulpes fulva) and raccoons (Procyon lotor) released at colonies of herring gulls (Larus argentatus) on islands off the Massachusetts coast effectively eliminated the production of young gulls. Annual predator introductions for 2-4 years caused major reductions in colony size and occasionally total abandonment of the island as a colony site. Observations of the experimental islands for 2 years after cessation of predator introductions showed slow repopulation of the islands and lower breeding success than on control islands. The size of the regional population was reduced largely because of the movements of gulls off the experimental islands. The introduced predators are, in most cases, difficult to maintain on the islands; this restricts their utility in population management.

  7. Retraction of a longevity record for a 36-year-old herring gull

    USGS Publications Warehouse

    Jonkel, G.M.; Pettingill, O.S., Jr.

    1974-01-01

    Full text: The longevity record for a 36-year-old Herring Gull, Larus argentatus (Pettingill 1967, Auk 84: 123), is erroneous. Herring Gull with band number A-676871, the basis of the record, was found dead on 20 June 1966 on the shore of Little Traverse Bay near Petoskey, Michigan, and reported to the Bird Banding Laboratory. The laboratory then mistakenly advised Pettingill that this gull was banded by him on 29 June 1930 on coastal Maine. He actually banded Herring Gull number A-676871 as a young bird on one of the Beaver Islands in Lake Michigan on 8 July 1948. The gull was thus 18 instead of 36 years old.

  8. Gulls Are Not "Seagulls"

    ERIC Educational Resources Information Center

    Wheat, Maxwell Corydon, Jr.

    1976-01-01

    The word "seagull" is included in the dictionary because the term is so often applied by the lay persons to almost any gull they notice. However, this is a generalized term which ignores the wide and facinating variety of the species. This article discusses some of the species of gulls. (NQ)

  9. Effects of gulls on Piping Plover nest site selection at Monomoy National Wildlife Refuge, Massachusetts

    USGS Publications Warehouse

    Keane, S.E.; Fraser, J.D.; Buckley, P.A.

    2001-01-01

    We examined the effects of Herring and Great Black-backed Gulls on Piping Plover nest site selection on South Monomoy Island, MA, from 1998 to 2000. We compared Piping Plover behavior and nest site selection in a gull-free area to a gull area, and compared Piping Plover nesting area characteristics to areas not used by plovers. We found no difference in the frequency of disturbance by gulls to pre-nesting adult plovers between the two areas. We found fewer gulls near pre-nesting adults than near random points, and fewer gulls in Piping Plover nesting areas than in areas not used by plovers. Proximity to prime foraging habitats and available nesting habitat (wide stretches of open vegetation) may be more important to Piping Plover nest site selection than the presence of gulls.

  10. Gulls identified as major source of fecal pollution in coastal waters: a microbial source tracking study.

    PubMed

    Araújo, Susana; Henriques, Isabel S; Leandro, Sérgio Miguel; Alves, Artur; Pereira, Anabela; Correia, António

    2014-02-01

    Gulls were reported as sources of fecal pollution in coastal environments and potential vectors of human infections. Microbial source tracking (MST) methods were rarely tested to identify this pollution origin. This study was conducted to ascertain the source of water fecal contamination in the Berlenga Island, Portugal. A total of 169 Escherichia coli isolates from human sewage, 423 isolates from gull feces and 334 water isolates were analyzed by BOX-PCR. An average correct classification of 79.3% was achieved. When an 85% similarity cutoff was applied 24% of water isolates were present in gull feces against 2.7% detected in sewage. Jackknifing resulted in 29.3% of water isolates classified as gull, and 10.8% classified as human. Results indicate that gulls constitute a major source of water contamination in the Berlenga Island. This study validated a methodology to differentiate human and gull fecal pollution sources in a real case of a contaminated beach. PMID:24140684

  11. Model of inner shelf shoal development, Beaufort Sea, Alaska

    SciTech Connect

    Lowry, P.; Nummedal, D.; Reimnitz, E.

    1985-01-01

    At least two types of inner shelf shoals exist in the Beaufort Sea, Alaska. One type is located up to 40 km from the shoreline in an average water depth of 20m and oriented obliquely to the coast. A second type of shoals occur adjacent to existing barrier islands where minimum water depth over the shoal crest may be as little as 30-50cm. The development of shallow water shoals is believed to be a result of barrier island submergence. Dinkum Sands is an example of a shallow water shoal. This linear sand body is located between Cross and Narwhal Islands, 25km northeast of Prudhoe Bay. The shoal complex is 8 km long and less than 2 km wide and has a maximum relief of 5m. Historical data reveal submergence of an island over at least a 25 year period. The proposed initial stage of shoal development occurs when longshore sediment transport between barrier islands is disrupted by numerous events of downdrift tidal inlet breaching. Reduction in the amount of available sediment to each island results in significant coastal erosion (stage 2), manifest as a landward migration of the shoreline and a reduction in barrier elevation. The final stage of the model is barrier submergence. At present the greatest accumulation of sediment on Dinkum Sands occur at the distal extremities of the shoal. These are believed to represent the location of recurved spits at either end of the island prior to submergence. Application of the submergence model to explain deepwater shoal development must await the collection of shallow (10m) whole core data.

  12. Trinity shoal: a reworked deltaic barrier on Louisiana continental shelf

    SciTech Connect

    Suter, J.R.; Penland, S.; Moslow, T.F.

    1985-02-01

    Abandonment and reworking of deltaic complexes of the Holocene Mississippi River have produced a series of sandy shoals on the muddy Louisiana continental shelf. Trinity shoal, one of these transgressive deposits, is located 30 km offshore of Atchafalaya Bay and the Point Au Fer-March Island shell reefs. Approximately 1000 km of high-resolution uniboom and 3.5 kHz subbottom-profile seismic data, taken in this area in 1983 and 1984, provide the data base for this study. Trinity shoal, associated with the abandoned Maringouin delta complex, is a lunate shore-parallel feature approximately 36 km long and 5-10 km wide. Relief on the shoal ranges from 2 to 3 m, and minimum water depths over the shoal vary from -5 to -2 m. The shoal sand body is from 5 to 7 m thick and is composed largely of parallel to low-angle clinoform reflectors. Several levels of buried fluvial channels, ranging in age from early Wisconsinian to Holocene, are associated with the shoal deposit. The occurrence of channel features within the shoal sand itself suggests the presence of tidal inlets, indicating a possible barrier-island origin for the shoal. The underlying deltaic sediments reach approximately 15 m in thickness and are made up of low-angle clinoform reflectors dipping to the southwest. Distributary, bay-fill, estuarine, and buried oyster-reef deposits can be recognized, making these similar to modern Atchafalaya delta deposits. Continued progradation of the Atchafalaya delta will probably result in burial of the Trinity shoal and Maringouin delta deposits by fine-grained sediments, giving these shoal deposits a high-preservation potential and creating an excellent stratigraphic trap.

  13. Migration and morphologic evolution of an ebb-tidal delta shoal, Chincoteague Inlet, Virginia

    SciTech Connect

    Barlet, K.E.; Simpson, E.L. ); Venn, C. ); Zimmerman, R. )

    1994-03-01

    Ebb-tidal delta shoals form as a result of the dynamic interaction of tide-, wave-, and storm-generated currents. A limited number of studies have tracked the long-term migration of an ebb-tidal delta shoal and the morphologic changes that result from the passage of a hurricane or a northeaster. The authors examined an ebb-tidal delta shoal in chincoteague Inlet, virginia by two methods. Aerial photographs from 1974 to 1991 were used to track shoal position and shoreline changes. Plane table mapping of the shoal from 1990 through 1992 allowed assessment of morphologic changes before and after the passage of storms. Aerial photographs indicated that the shoal migrated southward from 1974 to approximately 1981; superimposed on the southward migration is a counterclockwise rotation of the shoal. From 1981 through 1991 the shoal moved first towards Wallops Island, VA, to the west, then traveled northward; superimposed on the northward migration is a clockwise rotation of the shoal. Overall the shoal is inscribing a large clockwise pattern possibly the result of wave and longshore drift interaction. Alternatively, the shift of the shoal towards Wallops Island during the overall clockwise movement may be in part the result of sediment transport landward during storms. The smaller apparent rotations during southward and northward migration may be the result of a stronger flood tidal current in the main channel during southward migration and in the smaller southern flood tidal channel during northward migration.

  14. Parasitic fauna of a yellow-legged gull colony in the island of Escombreras (South-eastern Mediterranean) in close proximity to a landfill site: potential effects on cohabiting species.

    PubMed

    Parejo, Sandra Hervías; Martínez-Carrasco, Carlos; Diaz, Julia I; Chitimia, Lidia; Ortiz, Juana; Mayo, Elvira; Ybáñez, Rocío Ruiz de

    2015-06-01

    We identified the ectoparasites and helminth fauna of yellow-legged gulls (Larus michahellis michahellis), breeding near to a solid waste landfill, and compared infection levels with those of other yellow-legged gull colonies. Moreover, we analysed correlations between parasites and sex and body condition of yellow-legged gulls, co-infections and the helminth community structure in order to propose the role of this species as reservoir of certain parasites. We also discuss the potential transmission of parasites between the yellow-legged gull and the endangered Audouin's gull, because interactions between these two species, such as kleptoparasitism and predation, occur frequently around colonies. The following species were recorded: Ornithodorus capensis (Arthropoda); Cosmocephalus obvelatus, Paracuaria adunca, Eucoleus contortus, Tetrameres skrjabini and Contracaecum sp. (Nematoda); Tetrabothrius cylindraceus (Cestoda); Acanthotrema armata, Cardiocephaloides longicollis and Ornithobilharzia intermedia (Digenea). Tetrabothrius cylindraceus, A. armata and O. capensis are new parasite records for this host. The dependence of yellow-legged-gulls on fishery discards is supported by the dominance of parasites transmitted through marine intermediate hosts with interest to fisheries in the study area. However, the shift in diet from natural resources to food derived from human activities seems not to affect the parasitic fauna of yellow-legged gull. Besides of direct physical contact between individuals in nesting and resting habitats, the high availability of fishery discards could increase the risk of Audouin's gulls to be infected by common parasites of yellow-legged gull. PMID:26203998

  15. Forster's tern chick survival in response to a managed relocation of predatory California gulls

    USGS Publications Warehouse

    Ackerman, Joshua T.; Herzog, Mark P.; Hartman, C. Alex; Herring, Garth

    2014-01-01

    Gull populations can severely limit the productivity of waterbirds. Relocating gull colonies may reduce their effects on nearby breeding waterbirds, but there are few examples of this management strategy. We examined gull predation and survival of Forster's tern (Sterna forsteri) chicks before (2010) and after (2011) the managed relocation of the largest California gull (Larus californicus) colony (24,000 adults) in San Francisco Bay, California. Overall, survival of radio-marked Forster's tern chicks from hatching to fledging was 0.22 ± 0.03 (mean ± SE), and daily survival rates increased with age. Gulls were the predominant predator of tern chicks, potentially causing 54% of chick deaths. Prior to the gull colony relocation, 56% of radio-marked and 20% of banded tern chicks from the nearest tern colony were recovered dead in the gull colony, compared to only 15% of radio-marked and 4% of banded chicks recovered dead from all other tern colonies. The managed relocation of the gull colony substantially increased tern chick survival (by 900%) in the nearby (3.8 km) reference tern colony (0.29 ± 0.10 in 2010 and 0.25 ± 0.09 in 2011). Among 19 tern nesting islands, fledging success was higher when gull abundance was lower at nearby colonies and when gull colonies were farther from the tern colony. Our results indicate that the managed relocation of gull colonies away from preferred nesting areas of sensitive waterbirds can improve local reproductive success, but this conservation strategy may shift gull predation pressure to other areas or species.

  16. Heavy metal concentrations in Black-tailed Gull (Larus crassirostris) chicks, Korea.

    PubMed

    Kim, Jungsoo; Oh, Jon-Min

    2014-10-01

    The objectives of this study were to quantify concentrations of heavy metals in livers and stomach contents of Black-tailed Gull (Larus crassirostris) chicks from two islands in Korea. Iron and manganese concentrations were significantly higher in chick livers at Hongdo Island compared to Rando Islnad. In contrast, zinc, copper and cadmium concentrations were significantly higher at Rando Island than Hongdo Island. On Hongdo Island, Black-tailed Gull chicks at a lighthouse site had higher lead concentrations in livers and stomach contents than at a nearby reference site and stomach contents of Black-tailed Gull chicks had significantly higher lead concentrations than regurgitated diets. In Hongdo Island, manganese, lead and cadmium concentrations were significantly correlated between livers and stomach contents. Essential elements such as iron, zinc, manganese and copper concentrations from the present study were within the range reported for other seabird species including gulls. Livers of four individual gull chicks (13.3%) were at a level considered lead exposed (6-30 μg g(-1) dry weight), but cadmium concentrations in all specimens were within the background level (<3 μg g(-1) dry weight) for wild birds. Elevated lead concentrations on lighthouse site may be attributed to ingestion of paint chips and these concentrations may negatively affect chick behavior, growth and survival. PMID:25048929

  17. French Frigate Shoals reef health survey

    USGS Publications Warehouse

    Work, Thierry M.; Coles, Steve L.; Rameyer, Robert

    2002-01-01

    French Frigate Shoals consists of a large (31 nm) fringing reef partially enclosing a lagoon. A basalt pinnacle (La Perouse Pinnacle) arises approximately halfway between the two ends of the arcs of the fringing reefs. Tern Island is situated at the northern end of the lagoon and is surrounded by a dredged ship channel. The lagoon becomes progressively shallower from west to east and harbors a variety of marine life including corals, fish, marine mammals, and sea turtles (Amerson 1971). In 2000, an interagency survey of the northwestern Hawaiian Islands was done to document the fauna and flora in FFS (Maragos and Gulko, 2002). During that survey, 38 stations were examined, and 41 species of stony corals were documented, the most of any of the NW Hawaiian islands (Maragos and Gulko 2002). In some of these stations, corals with abnormalities were observed. The present study aimed to expand on the 2000 survey to evaluate the lesions in areas where they were documented.

  18. Reductions in Gull Populations Improve Beachwater Quality.

    EPA Science Inventory

    BACKGROUND. Gulls are often cited as an important source of fecal pollution to surface waters, and fecal indicator bacteria (FIB) concentrations have been shown to be significantly correlated with gull populations. However, it is unclear whether gull contamination poses a risk to...

  19. Migration and wintering areas of glaucous-winged Gulls from south-central Alaska

    USGS Publications Warehouse

    Hatch, Shyla A.; Gill, V.A.; Mulcahy, D.M.

    2011-01-01

    We used satellite telemetry to investigate the migration patterns and wintering areas of Glaucouswinged Gulls (Larus glaucescens) from Middleton Island, Alaska, where this species' population increased tenfold from the 1970s to the 1990s. Fall migration spanned 11 weeks, including numerous stopovers en route, apparently for feeding. Spring migration from wintering sites to Middleton Island was shorter (4 weeks) and more direct. One juvenile spent several months in southern Prince William Sound. An adult spent several months near Craig, southeast Alaska, while three others overwintered in southern British Columbia. For all four wintering adults use of refuse-disposal sites was evident or strongly suggested. Commensalism with humans may have contributed to the increase on Middleton, but a strong case can also be made for a competing explanation-regional recruitment of gulls to high-quality nesting habitat in Alaska created after the earthquake of 1964. An analysis of band returns reveals broad overlap in the wintering grounds of gulls from different Alaska colonies and of gulls banded on the west coast from British Columbia to California. The seasonal movement of many gulls from Alaska is decidedly migratory, whereas gulls from British Columbia, Washington, and Oregon disperse locally in winter. ?? The Cooper Ornithological Society 2011.

  20. Migration And wintering areas Of Glaucous-winged Gulls From south-central Alaska

    USGS Publications Warehouse

    Hatch, Scott A.; Gill, V.A.; Mulcahy, Daniel M.

    2011-01-01

    We used satellite telemetry to investigate the migration patterns and wintering areas of Glaucous-winged Gulls (Larus glaucescens) from Middleton Island, Alaska, where this species' population increased tenfold from the 1970s to the 1990s. Fall migration spanned 11 weeks, including numerous stopovers en route, apparently for feeding. Spring migration from wintering sites to Middleton Island was shorter (4 weeks) and more direct. One juvenile spent several months in southern Prince William Sound. An adult spent several months near Craig, southeast Alaska, while three others overwintered in southern British Columbia. For all four wintering adults use of refuse-disposal sites was evident or strongly suggested. Commensalism with humans may have contributed to the increase on Middleton, but a strong case can also be made for a competing explanation-regional recruitment of gulls to high-quality nesting habitat in Alaska created after the earthquake of 1964. An analysis of band returns reveals broad overlap in the wintering grounds of gulls from different Alaska colonies and of gulls banded on the west coast from British Columbia to California. The seasonal movement of many gulls from Alaska is decidedly migratory, whereas gulls from British Columbia, Washington, and Oregon disperse locally in winter.

  1. Structure of the New England herring gull population

    USGS Publications Warehouse

    Kadlec, J.A.; Drury, W.H.

    1968-01-01

    Measurements of the rates of population increase, reproduction, and mortality together with an observed age ratio, were used to analyze the population of the Herring Gull in New England. Data from sporadic censuses prior to this study, aerial censuses by the authors, and National Audubon Society Christmas Bird Count indicated that the New England breeding population has been doubling every 12 to 15 years since the early 1900's. This increase has involved founding new colonies and expanding the breeding range There is evidence that 15 to 30% of the adults do not breed in any given year. Sixty-one productivity measurements on 43 islands from 1963 through 1966, involving almost 13,000 nests, showed that from 0.8 to 1.4 young/breeding pair/year is the usual range of rate of production. The age distribution in the population was determined by classifying Herring Gulls by plumage category on an aerial census of the coast from Tampico, Mexico, to Cape Sable, Nova Scotia. Of the 622,000 gulls observed, 68% were adults, 17% were second- and third-year birds, and 15% were first-year birds. Mortality rates derived from band recovery data were too high to be consistent with the observed rate of population growth, productivity, and age structure. Loss of bands increasing to the rate of about 20%/year 5 years after banding eliminates most of the discrepancy. The age structure and rate of population increase indicate a mortality rate of 4 to 9% for gulls 2 years old or older, compared with the 25 to 30% indicated by band recoveries. The population structure we have developed fits everything we have observed about Herring Gull population dynamics, except mortality based on band recoveries.

  2. Shoal, Nevada Site Fact Sheet

    SciTech Connect

    2009-04-01

    The Shoal Site is situated on 2,560 acres of withdrawn federal lands located within the north-central portion of the Sand Springs Range in Churchill County, Nevada. The town of Fallon is the largest populated area in the region and is about 30 miles northwest of the site. The region around the Shoal Site is sparsely populated; military installations, recreation, ranching, and mining provide the dominant commercial interests. The Project Shoal underground nuclear test was part of the Vela Uniform program sponsored jointly by the U.S Department of Defense and U.S. Atomic Energy Commission (AEC), a predecessor agency of the U.S. Department of Energy (DOE). Vela Uniform was a research and development program directed toward locating, detecting, and identifying underground detonations. The objective of Project Shoal was to detonate a nuclear device underground in an active seismic area to improve the United States' ability to detect, identify, and locate underground nuclear detonations.

  3. Annual Movement Patterns of Endangered Ivory Gulls: The Importance of Sea Ice

    PubMed Central

    Spencer, Nora C.; Gilchrist, H. Grant; Mallory, Mark L.

    2014-01-01

    The ivory gull (Pagophila eburnea) is an endangered seabird that spends its entire year in the Arctic environment. In the past three decades, threats from various sources have contributed to a >70% decline in Canada. To assess the annual habitat needs of this species, we attached satellite transmitters to 12 ivory gulls on Seymour Island, Nunavut in 2010, which provided up to four breeding seasons of tracking data. Analysis of migratory behaviour revealed considerable individual variation of post-breeding migratory route selection. Ivory gulls traveled a median of 74 days during post-breeding migration, but only 18 days during pre-breeding migration. In contrast to predictions, ivory gulls did not use the Greenland coast during migratory periods. Ivory gulls overwintered near the ice edge in Davis Strait, but also used the Labrador Sea in late February and March. We suggest that the timing of formation and recession and extent of sea ice plays a large role in ivory gull distribution and migratory timing. PMID:25551556

  4. Parathion alters incubation behavior of laughing gulls

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Hill, E.F.

    1983-01-01

    One member of each pair of incubating laughing gulls at 9 nests was trapped, orally dosed with either 6 mg/kg parathion in corn oil or corn oil alone, and marked about the neck with red dye. Each nest was marked with a numbered stake and the treatment was recorded. A pilot study with captive laughing gulls had determined the proper dosage of parathion that would significantly inhibit their brain AChE activity (about 50% of normal) without overt signs of poisoning. After dosing, birds were released and the nests were observed for 2 1/2 days from a blind on the nesting island. The activities of the birds at each marked nest were recorded at 10-minute intervals. Results indicated that on the day of treatment there was no difference (P greater than 0.05, Chi-square test) in the proportion of time spent on the nest between treated and control birds. However, birds dosed with 6 mg/kg parathion spent significantly less time incubating on days 2 and 3 than did birds receiving only corn oil. By noon on the third day, sharing of nest duties between pair members in the treated group had approached normal, indicating recovery from parathion intoxication. These findings suggest that sublethal exposure of nesting birds to an organophosphate (OP) insecticide, such as parathion, may result in decreased nest attentiveness, thereby making the clutch more susceptible to predation or egg failure. Behavioral changes caused by sublethal OP exposure could be especially detrimental in avian species where only one pair member incubates or where both members are exposed in species sharing nest duties.

  5. Density-independent survival of wild lake trout in the Apostle Islands area of Lake Superior

    USGS Publications Warehouse

    Bronte, Charles R.; Schram, Stephen T.; Selgeby, James H.; Swanson, Bruce L.

    1995-01-01

    The lake trout (Salvelinus namaycush) stock at Gull Island Shoal in western Lake Superior was one of only a few stocks of lean lake trout in the Great Lakes that survived overfishing and predation by the sea lamprey (Petromyzon marinus). Since the mid 1960s, the abundance of wild recruits measured at age 0 and the number of age-7 to -11 wild fish recruited to the fishable stock have increased. We used the Varley-Gradwell method to test for density-dependent survival between these life stages. Survival from age-0 to ages 7–11 was not affected by increasing density, which suggests that further increases in recruitment and stock size are still possible. We suggest that testing for the existence of density-dependent survival can be used to indicate when lake trout populations are rehabilitated.

  6. Avian Bornaviruses in North American Gulls.

    PubMed

    Guo, Jianhua; Tizard, Ian; Baroch, John; Shivaprasad, H L; Payne, Susan L

    2015-07-01

    Avian bornaviruses, recently described members of the family Bornaviridae, have been isolated from captive parrots and passerines as well as wild waterfowl in which they may cause lethal neurologic disease. We report detection of avian bornavirus RNA in the brains of apparently healthy gulls. We tested 439 gull brain samples from 18 states, primarily in the northeastern US, using a reverse-transcriptase PCR assay with primers designed to detect a conserved region of the bornavirus M gene. Nine birds yielded a PCR product of appropriate size. Sequencing of PCR products indicated that the virus was closely related to aquatic bird bornavirus 1 (ABBV-1). Viral RNA was detected in Herring Gulls (Larus argentatus), Ring-billed Gulls (Larus delawarensis), and Laughing Gulls (Leucophaeus atricilla). Eight of the nine positive birds came from the New York/New Jersey area. One positive Herring Gull came from New Hampshire. Histopathologic examination of one well-preserved brain from a Herring Gull from Union County New Jersey, showed a lymphocytic encephalitis similar to that observed in bornavirus-infected parrots and geese. Bornavirus N protein was confirmed in two Herring Gull brains by immunohistochemistry. Thus ABBV-1 can infect gulls and cause encephalitic brain lesions similar to those observed in other birds. PMID:25973630

  7. No. 2 fuel oil decreases embryonic survival of great black-backed gulls

    USGS Publications Warehouse

    Coon, N.C.; Albers, P.H.; Szaro, R.C.

    1979-01-01

    Field study of the effects of No. 2 fuel oil applications to the eggs of great black-backed gulls on an island off the coast of Maine. Fuel oil applied in amounts of either 5 or 20 ul. All eggs opened 8 da later. Measured survival and estimated age of embryo at time of egg oiling.

  8. Shoaling in juvenile guppies: the effects of body size and shoal size.

    PubMed

    Ledesma, J M; McRobert, S P

    2008-03-01

    While factors affecting shoal mate choice have been examined extensively in adult guppies (Poecilia reticulata), few studies have focused on the shoaling behavior of juveniles. In this study, juvenile guppies were tested for their ability to shoal as well as their response to shoal mates of different body size and to shoals with different numbers of individuals. In dichotomous choice tests, 10-day-old guppies (mean body length=8.83 mm), 30-day-old guppies (13.17 mm) and 50-day-old guppies (18.6mm) were given the opportunity to swim near shoals of five fish or an empty chamber. In most cases, the juvenile fish demonstrated shoaling behavior, swimming near a group of fish rather than an empty chamber, regardless of the age of the stimulus shoal. When presented with two shoals, one of similar age and body size and one of dissimilar age and body size, only the 50-day-old guppies showed a significant preference for the age-matched shoal. Similarly, when choosing between a large shoal and a small shoal, only the 50-day-old guppies spent significantly more time near the larger shoal. Thus, while juveniles at each age shoaled, only 50-day-old fish demonstrated the shoal mate discrimination seen in adult fish. PMID:18061375

  9. Breeding biology and relation of pollutants to black skimmers and gull-billed terns in South Carolina

    USGS Publications Warehouse

    Blus, Lawrence J.; Stafford, Charles J.

    1980-01-01

    The breeding biology and relation of pollutants to black skimmers (Ryn chops niger) and gull-billed terns (Gelochelidon nilotica) were investigated in South Carolina from 1969 through 1975. With few exceptions, the two species nested together in colonies located on barrier islands. We located 10 colonies, 7 of which were on the Cape Romain National Wildlife Refuge (Cape Romain); references were located that described nesting on seven other islands in South Carolina that no longer support colonies. Gull-billed terns nested from early May through July; the skimmers started later (late May) but also continued later (early September). Both species nested in areas subject to tidal flooding, and the two species persisted in nesting in several colonies despite intense predation by rats and gulls. Estimated reproductive success varied greatly from year to year and colony to colony; success in most colonies seemed low, particularly for the gull-billed tern. Residues of organochlorine pollutants in several eggs seemed of sufficient magnitude to induce adverse effects on reproductivity and eggshell thickness: however, the overall effect of organochlorines appeared negligible. Maximum numbers of nests located in a single year were 790 for the skimmer and 340 for the gull-billed tern: the total breeding population in South Carolina is unknown. Although nesting islands at Cape Romain and Deveaux Bank are sanctuaries for nesting birds, both species will continue to lose nesting habitat as additional sea islands are developed and inhabited by man.

  10. Aspects of chick growth in Gull-billed Terns in coastal Virginia

    USGS Publications Warehouse

    Erwin, R.M.; Eyler, T.B.; Stotts, D.B.; Hatfield, J.S.

    1999-01-01

    Because of concerns about apparent population declines and low productivity of Gull-billed Terns (Sterna nilotica) along the coast of Virginia, we investigated whether food limitations may result in retarded growth rates of young. Several colonies of Gull-billed Terns were monitored from May to July each year from 1994 to 1996 on both sandy barrier islands and marsh/shellpile islands in coastal Virginia. Nests were visited one to three times a week to monitor clutch size and hatching success, and enclosures were installed around selected nests to monitor chick growth from hatching to at least two weeks of age. When comparing chick growth, we found significant year, habitat and hatch order effects. Chicks from marsh shellpiles had higher mass and culmen growth rates than did those from barrier islands, and first-hatched (A) chicks had significantly higher culmen growth rates than did second-hatched (B) chicks. Year effects were only found for mass growth rates. Growth rates of Gull- billed Terns in these Virginia colonies seem to be low relative to those of six other North American tern species from other geographic areas. These findings suggest that growth rates of young Gull-billed Terns, as well as other reproductive parameters, need to be examined in detail in other coastal areas such as Texas, where the species is more abundant, to determine whether our growth results are species- or region-specific.

  11. Dioxins, furans and AHH-active PCB congeners in eggs of two gull species from the western Mediterranean.

    PubMed

    Pastor, D; Ruiz, X; Barceló, D; Albaigés, J

    1995-09-01

    Polychlorinated biphenyls, dibenzodioxins and dibenzofurans were analysed in eggs of a protected gull species, the Audouin's Gull (Larus audouinii) and compared to those of the Yellow-legged Gull (Larus cachinnans), both breeding in the Western Mediterranean (Ebro Delta and Medes Islands, respectively). Differences in concentrations as well as in congener profiles reflected differences in both habitat and diet of the two species. Levels of AHH-active PCB congeners were lower in Yellow-legged Gull (0.4-1.6 micrograms/g d.w) than in Audouin's Gull eggs (1.2-33.9 micrograms/g d.w.). These concentrations, expressed in international toxic equivalence factors (i-TEQ/g d.w.), were on average 24 times higher in the Audouin's gull. I-TEQ levels due to dioxins were also higher in this species by a factor of ca. 7. I-TEQ levels related to PCBs resulted 90-230 times higher than those of dioxins and furans. Thus, AHH-inducing PCBs might represent even higher toxicological hazards than dioxins and furans to some populations of seabirds. The necessity of assessing the impact of these compounds in rare and protected species is pointed out. PMID:8528648

  12. Effects of organochlorine contaminants on thyroid hormone levels in Arctic breeding glaucous gulls, Larus hyperboreus.

    PubMed Central

    Verreault, Jonathan; Skaare, Janneche Utne; Jenssen, Bjørn Munro; Gabrielsen, Geir Wing

    2004-01-01

    Studies on glaucous gulls (Larus hyperboreus) breeding in the Barents Sea have reported that high blood levels of halogenated organic contaminants in this species might cause reproductive, behavioral, and developmental stress. However, potential endocrine system modulation caused by contaminant exposure has yet not been reported in this Arctic apical predator. In this present study we aimed to investigate whether the current levels of a selection of organochlorines (OCs) were associated with altered circulating levels of thyroid hormones (THs) in free-ranging adult glaucous gulls breeding at Bear Island in the Barents Sea. Blood concentrations of 14 polychlorinated biphenyls, hexachlorobenzene (HCB), oxychlordane, and p,p' -dichlorodiphenyldichloroethylene (p,p' -DDE) were quantified, in addition to free and total thyroxine (T4) and triiodothyronine (T3), in plasma of 66 glaucous gulls in the spring of 2001. Negative correlations were found between plasma levels of T4 and T4:T3 ratio, and blood levels of OCs in male glaucous gulls. Despite their relatively low contribution to the total OC fraction, HCB and oxychlordane were the most prominent compounds in terms of their negative effect on the variation of the T4:T3 ratio. Moreover, lower T4 levels and T4:T3 ratios were measured in glaucous gulls breeding in a colony exposed to high levels of OCs, compared with a less exposed colony. Levels of T3 were elevated in the high-OC-exposed colony. This may indicate that the glaucous gull is susceptible to changes to TH homeostasis mediated by exposure to halogenated organic contaminants. PMID:15064156

  13. Dramatic Improvements in Beach Water Quality Following Gull Removal

    EPA Science Inventory

    Gulls are often cited as important contributors of fecal contamination to surface waters, and some recreational beaches have used gull control measures to improve microbial water quality. In this study, gulls were chased from a Lake Michigan beach using specially trained dogs, a...

  14. Mercury levels in Great Lakes herring gull eggs, 1972--1992

    SciTech Connect

    Weseloh, D.V.; Koster, M.D.; Ryckman, D.P.; Struger, J.

    1995-12-31

    Since 1971, the herring gull (Larus argentatus) has been used as a sentinel species for monitoring the levels of persistent contaminants in the Great Lakes ecosystem. In this study, 21 herring gull colonies in the Great Lakes and connecting channels were sampled for years 1972--1976, 1981--1983, 1985 and 1992. For each year, 10 eggs (usually) were collected from each colony site and analyzed for total mercury (ppm, wet weight). Results indicated that eggs from Lake Ontario displayed the highest mercury levels, mean = 0.28 (s.d. = 0.08) to 0.73 (0.23). Lake Erie typically displayed the lowest egg mercury levels, 0.18 (0.08) to 0.24 (0.11). Overall, mercury levels ranged from 0.12 (0.02) in 1985 to 0.88 (0.23) in 1982 for Channel-Shelter Island (Lake Huron) and Pigeon Island (Lake Ontario), respectively. Generally, all colony sites showed peak mercury levels in 1982. A significant decline in egg mercury levels was observed in six colony sites between 1972 and 1992 and in three colony sites between 1981 and 1992. The mean herring gull egg mercury levels observed in the early and mid 1970s and in 1982 for some colony sites were within the range found which potentially reduces hatchability in other fish-eating bird species.

  15. Retrospective analysis of organophosphate flame retardants in herring gull eggs and relation to the aquatic food web in the Laurentian Great Lakes of North America.

    PubMed

    Greaves, Alana K; Letcher, Robert J; Chen, Da; McGoldrick, Daryl J; Gauthier, Lewis T; Backus, Sean M

    2016-10-01

    With the phase-out and regulation of some flame retardant chemicals, the production and usage of organophosphate triester flame retardants (OPFRs) has increased in recent years. In the present study, 14 OPFRs (either chlorinated, brominated or non-halogenated) were analyzed in egg pools of 10-13 individual herring gull eggs from five colonial nesting sites for 11 years spanning 1990-2010, (for a total of n=55 egg pools) in the Laurentian Great Lakes of North America (Chantry Island, Fighting Island, Agawa Rocks, Toronto Harbour and Gull Island). OPFR profiles varied slightly between colony sites and collection years. For all five sites tris(2-chloroisopropyl) phosphate (TCIPP), tris(2-chloroethyl) phosphate (TCEP) and tris(2-butoxyethyl) phosphate (TBOEP) were detected, while triphenyl phosphate (TPHP) was only quantifiable in eggs from Chantry Island and Gull Island collected in 2008 and 2010. For the 2010 egg pools, the ΣOPFR concentrations were generally low and ranged from 2.02 to 6.69 ng/g wet weight (ww). ΣOPFR concentrations in 2010 were significantly higher (p<0.05) than they were between 1990 and 2004 (4.06 vs. 1.55 ng/g ww, respectively). In a pilot examination of Great Lakes aquatic food webs, 2010-collected alewife and rainbow smelt (major herring gull fish prey) and lake trout from western Lake Erie and Ontario, only contained TBOEP at low to sub ng/g ww concentrations. These results demonstrate that low to sub-ppb concentrations of at least three OPFRs, TCIPP, TCEP and TBOEP, have been persistent in herring gull eggs from the Great Lakes for at least the past 20 years, probably bioaccumulate mainly via the fish diet, and are transferred to the eggs of exposed herring gulls. PMID:27322497

  16. Depredation of common eider, Somateria mollissima, nests on a central Beaufort Sea barrier island: A case where no one wins

    USGS Publications Warehouse

    Reed, J.A.; Lacroix, D.L.; Flint, P.L.

    2007-01-01

    Along the central Beaufort Sea, Pacific Common Eiders (Somateria mollissima v-nigra) nest on unvegetated, barrier islands; often near nesting Glaucous Gulls (Larus hyperboreus). Nest-site choice likely reflects a strategy of predator avoidance: nesting on islands to avoid mammalian predators and near territorial gulls to avoid other avian predators. We observed a nesting colony of Common Eiders from first nest initiation through nesting termination on Egg Island near Prudhoe Bay, Alaska (2002 - 2003). Resident gulls depredated many eider nests, mostly during initiation. All nests failed when an Arctic Fox (Alopex lagopus) visited the island and flushed hens from their nests, exposing the eggs to depredation by the fox and gulls (resident and non-resident). Common Eiders actively defended nests from gulls, but not from foxes. Likely all three species (i.e., eiders, gulls, and foxes) ultimately achieved negligible benefit from their nest-site selection or predatory activity: (a) island nesting provided no safety from mammalian predators for eiders or gulls, (b) for Common Eiders, nesting near gulls increased egg loss, (c) for Glaucous Gulls, nesting near colonial eiders may have reduced nest success by attracting the fox, and (d) for Arctic Foxes, the depredation was of questionable value, as most eggs were cached and probably not recoverable (due to damage from fall storms). Thus, the predator-prey interactions we observed appear to be a case where little or no fitness advantage was realized by any of the species involved.

  17. Mercury and other metals in eggs and feathers of glaucous-winged gulls (Larus glaucescens) in the Aleutians

    PubMed Central

    Gochfeld, Michael; Jeitner, Christian; Burke, Sean; Volz, Conrad D.; Snigaroff, Ronald; Snigaroff, Daniel; Shukla, Tara; Shukla, Sheila

    2014-01-01

    Levels of mercury and other contaminants should be lower in birds nesting on isolated oceanic islands and at high latitudes without any local or regional sources of contamination, compared to more urban and industrialized temperate regions. We examined concentrations of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in the eggs, and the feathers of fledgling and adult glaucous-winged gulls (Larus glaucescens) nesting in breeding colonies on Adak, Amchitka, and Kiska Islands in the Aleutian Chain of Alaska in the Bering Sea/North Pacific. We tested the following null hypotheses: 1) There were no differences in metal levels among eggs and feathers of adult and fledgling glaucous-winged gulls, 2) There were no differences in metal levels among gulls nesting near the three underground nuclear test sites (Long Shot 1965, Milrow 1969, Cannikin 1971) on Amchitka, 3) There were no differences in metal levels among the three islands, and 4) There were no gender-related differences in metal levels. All four null hypotheses were rejected at the 0.05 level, although there were few differences among the three test sites on Amchitka. Eggs had the lowest levels of cadmium, lead, and mercury, and the feathers of adults had the lowest levels of selenium. Comparing only adults and fledglings, adults had higher levels of cadmium, chromium, lead and mercury, and fledglings had higher levels of arsenic, manganese and selenium. There were few consistent interisland differences, although levels were generally lower for eggs and feathers from gulls on Amchitka compared to the other islands. Arsenic was higher in both adult feathers and eggs from Amchitka compared to Adak, and chromium and lead were higher in adult feathers and eggs from Adak compared to Amchitka. Mercury and arsenic, and chromium and manganese levels were significantly correlated in the feathers of both adult and fledgling gulls. The feathers of males had significantly higher levels of chromium and

  18. Created versus natural coastal islands: Atlantic waterbird populations, habitat choices, and management implications

    USGS Publications Warehouse

    Erwin, R.M.; Allen, D.H.; Jenkins, D.

    2003-01-01

    Nesting colonial waterbirds along the Atlantic Coast of the United States face a number of landscape-level threats including human disturbance, mammalian predator expansion, and habitat alteration. There have been changes from 1977 to the mid-1990s in use of nesting habitats and populations of a number of seabird species of concern in the region, including black skimmers Rynchops niger Linnaeaus, common terns Sterna hirundo Linnaeaus, gull-billed terns Sterna nilotica Linnaeaus, least terns Sterna antillarum Lesson, royal terns Sterna maxima Boddaert, and sandwich terns Sterna sandvicensis Cabot. These species form colonies primarily on the following habitat types: large, sandy barrier or shoal islands, natural estuarine or bay islands (mostly marsh), man-made islands of dredged deposition materials (from navigation channels), and the mainland. Significant changes in the use of the dredged material islands have occurred for these species in New Jersey and North Carolina, but not in Virginia. Population declines and changes in bird habitat use appear to be at least partially associated with the conditions and management of the existing dredged material islands, coastal policy changes associated with creating new dredged material islands, and competing demands for sand for beach augmentation by coastal communities. As these and other coastal habitats become less suitable for colonial waterbirds, other manmade sites, such as bridges and buildings have become increasingly more important. In regions with intense recreational demands, coastal wildlife managers need to take a more aggressive role in managing natural and man-made habitats areas and as stakeholders in the decision-making process involving dredged materials and beach sand allocation.

  19. Levels and trends of organochlorines and brominated flame retardants in ivory gull eggs from the Canadian Arctic, 1976 to 2004.

    PubMed

    Braune, Birgit M; Mallory, Mark L; Grant Gilchrist, H; Letcher, Robert J; Drouillard, Ken G

    2007-06-01

    The ivory gull (Pagophila eburnea) is a circumpolar marine bird which has recently been listed as an endangered species in Canada. To determine whether contaminants may be playing a role in the population decline of this species, ivory gull eggs collected in 1976, 1987 and 2004 from Seymour Island in the Canadian Arctic were analyzed for organochlorines, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and non-ortho PCBs. This study also provides the first account of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs) and polybrominated biphenyls (PBBs) in ivory gulls. The most quantitatively abundant legacy organochlorines found in the ivory gull eggs were p,p'-DDE, SigmaPCB and oxychlordane. Concentrations of the organochlorines analyzed either decreased or showed little change between 1976 and 2004. Concentrations of SigmaPCDD in ivory gull eggs were greater than SigmaPCDF, and the non-ortho PCBs (primarily PCB-126) contributed the largest fraction to the total TEQ value in all years sampled. Concentrations of PCDDs, PCDFs and SigmaTEQ decreased from 1976 to 2004. In contrast, concentrations of the PBDEs steadily increased between 1976 and 2004 driven primarily by increases in BDE-47. Although concentrations of the persistent chlorinated compounds (i.e. organochlorine pesticides, PCBs, PCDDs, PCDFs) reported in this study were below published toxicological threshold values for eggs of wild birds, we cannot rule out the possibility of synergistic/additive, sublethal effects. Very few studies have been carried out to evaluate the exposure-effect relationship of the persistent brominated compounds in avian species. Given the scarcity of information on toxicity threshold levels for PBBs and PBDEs in avian species, coupled with the trend toward increasing concentrations in ivory gulls, continued monitoring and further toxicological studies of these compounds are warranted. PMID:17412396

  20. 78 FR 46410 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel TWO BUOYS ONE GULL...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-31

    ... GULL; Invitation for Public Comments AGENCY: Maritime Administration, Department of Transportation... the applicant the intended service of the vessel TWO BUOYS ONE GULL is: Intended Commercial Use...

  1. Landscape changes and colony site dynamics: How gull-billed terns cope at the sea's edge

    USGS Publications Warehouse

    Erwin, R.M.; Williams, B.; Watts, B.; Truitt, B.; Stotts, D.; Eyler, B.

    1996-01-01

    Gull-billed Terns have declined dramatically in coastal Virginia over the past 20 years, with apparently low reproductive success. They nest, usually in mixed-species colonies, in two discrete habitat types: large, sandy barrier islands or shell/sandbars on the edges of marsh islands in the lagoon systems. The smaller shell/sandbars seem to provide more consistent nestling habitat and predation pressures than do barrier islands among years. We hypothesize that colony site turnover (between years) should be higher in the more uncertain barrier island habitats than among the shell/sandbar colonies. Our results do not corroborate the prediction. We postulate that social (and other) factors may explain these differences.

  2. Extinction risk to herring gull populations from DDT exposure.

    PubMed

    Nakamaru, Mayuko; Iwasa, Yoh; Nakanishi, Junko

    2002-01-01

    The impact of toxic chemicals on wild animals and plants can be quantified in terms of the enhanced risk of population extinction. To illustrate the method, we estimated it for herring gull (Larus argentatus) populations in Long Island (NY, USA) exposed to DDT (p,p'-dichlorodiphenyltrichloroethane) and its metabolites (abbreviated as DDTs) with a strong biomagnification effect. The method is based on a formula of the mean time to population extinction derived for a stochastic differential equation (the canonical model). The intrinsic rate of natural population growth was estimated from the doubling time of an exponentially growing population and the intensity of the environmental fluctuation from the magnitude of population size fluctuation. The effect of exposure to DDTs in reducing the population growth rate was evaluated based on an age-structured population model by assuming that age-specific fertilities (including chick survivorship) are density dependent and sensitive to DDTs exposure but age-specific survivorships are not. The results are expressed in terms of the risk equivalent-the decrease in the carrying capacity K that causes the same enhancement of extinction risk as chemical exposure at a given level. The high concentration reported in Long Island in the 1960s corresponds to the equivalent loss of carrying capacity by 42.5% when K is 100 (the number of breeding females), and coefficient of variation (CV) = 0.2 (sigma2 = 0.0298) [corrected]. Risk equivalent allows us to compare different risk factors and is useful in mitigation banking. PMID:11804054

  3. 18. Photocopy, "Light house for ship shoals, details of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Photocopy, "Light house for ship shoals, details of the apparatus for inserting the piles into the shoal, sheet no. 53", National Archives (8" x 10" print from 4" x 5" negative) - Ship Shoal Light Station, Gulf of Mexico, Theriot, Terrebonne Parish, LA

  4. Trace element contamination in nestling black-tailed gulls (Larus crassirostris) in Korea.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2015-05-01

    At Hongdo Island, Gyeongsangnam-do, Korea, a breeding site of black-tailed gull (Larus crassirostris), we collected nestlings from two locations: a "reference" site (n = 10) with no known source of lead contamination and "lighthouse" site (n = 10) with suspected lead contamination from leaded paint. Iron concentrations in the kidney and bone, manganese in the muscle, copper in the bone, lead in the muscle and bone, and cadmium in the liver, muscle, and bone at the reference site were significantly higher than at the lighthouse. Manganese concentrations in the liver and kidney, and lead in the kidney were significantly greater at the lighthouse than at the reference site. Iron, zinc, manganese, copper, lead and cadmium concentrations had tissue-specific accumulation at both sites. Lead concentrations in 10 % of livers and in 80 % of kidneys at the lighthouse, and in 20 % of livers from the reference were within a range considered toxic (>6.00 μg/g dw in the liver and kidney). Lead concentrations in 50 % of black-tailed gull nestlings at the reference and 80 % nestlings at the lighthouse were greater in livers than in bones, which is suggestive of acute lead exposure. For cadmium, all liver and kidney concentrations from two sites were at a level considered background in birds. Cadmium concentrations of every sample were higher in kidneys than in livers, suggestive of chronic cadmium exposure. Lead concentrations in gull nestlings in the present study were relatively higher than other gull species worldwide, but cadmium concentrations were relatively lower. PMID:25763522

  5. Volcanic Island Appears Near Tonga

    NASA Astrophysics Data System (ADS)

    Zielinski, Sarah

    2006-11-01

    A volcano known as Home Reef is now believed to be the source of a small island that appeared recently in Tonga, accordingto scientists from the Smithsonian Institution's Global Volcanism Program who had initially placed the location of the eruption and resulting island at nearby Metis Shoal. Mariners onboard the yacht Maiken

  6. Data Decision Analysis: Project Shoal

    SciTech Connect

    Forsgren, Frank; Pohll, Greg; Tracy, John

    1999-01-01

    The purpose of this study was to determine the most appropriate field activities in terms of reducing the uncertainty in the groundwater flow and transport model at the Project Shoal area. The data decision analysis relied on well-known tools of statistics and uncertainty analysis. This procedure identified nine parameters that were deemed uncertain. These included effective porosity, hydraulic head, surface recharge, hydraulic conductivity, fracture correlation scale, fracture orientation, dip angle, dissolution rate of radionuclides from the puddle glass, and the retardation coefficient, which describes the sorption characteristics. The parameter uncertainty was described by assigning prior distributions for each of these parameters. Next, the various field activities were identified that would provide additional information on these parameters. Each of the field activities was evaluated by an expert panel to estimate posterior distribution of the parameters assuming a field activity was performed. The posterior distributions describe the ability of the field activity to estimate the true value of the nine parameters. Monte Carlo techniques were used to determine the current uncertainty, the reduction of uncertainty if a single parameter was known with certainty, and the reduction of uncertainty expected from each field activity on the model predictions. The mean breakthrough time to the downgradient land withdrawal boundary and the peak concentration at the control boundary were used to evaluate the uncertainty reduction. The radionuclide 137Cs was used as the reference solute, as its migration is dependent on all of the parameters. The results indicate that the current uncertainty of the model yields a 95 percent confidence interval between 42 and 1,412 years for the mean breakthrough time and an 18 order-of-magnitude range in peak concentration. The uncertainty in effective porosity and recharge dominates the uncertainty in the model predictions, while the

  7. Contaminant levels in Herring (Larus argentatus) and Great Black-backed Gull (Larus marinus) eggs from colonies in the New York harbor complex between 2012 and 2013

    PubMed Central

    Elbin, Susan

    2014-01-01

    Birds living in coastal areas are exposed to severe storms and tidal flooding during the nesting season, but also to contaminants that move up the food chain from the water column and sediment to their prey items. We examine metals in Herring Gull (Larus argentatus) and Great Black-backed Gull (Larus marinus) eggs collected from the New York/New Jersey harbor estuary in 2012 and in 2013 to determine if there were significant yearly differences in metal levels. We test the null hypothesis that there were no significant yearly differences in metal levels. We investigate whether there were consistent differences in metals from 2012 to 2013 that might suggest a storm-related effect because Superstorm Sandy landed in New Jersey in October 2012 with high winds and extensive flooding, and view this research as exploratory. Except for arsenic, there were significant inter-year variations in the mean levels for all colonies combined for Herring Gull, and for lead, mercury and selenium for Great Black-backed Gulls. All metal levels in 2013 were less than in 2012, except for lead. These differences were present for individual colonies as well. Metal levels varied significantly among islands for Herring Gulls in both years (except for cadmium in 2013). No one colony had the highest levels of all metals for Herring Gulls. A long term data set on mercury levels in Herring Gulls indicated that the differences between 2012 and 2013 were greater than usual. Several different factors could account for these differences, and these are discussed. PMID:25471353

  8. Estimates of Cl atom concentrations and hydrocarbon kinetic reactivity in surface air at Appledore Island, Maine (USA), during International Consortium for Atmospheric Research on Transport and Transformation/Chemistry of Halogens at the Isles of Shoals

    NASA Astrophysics Data System (ADS)

    Pszenny, Alexander A. P.; Fischer, Emily V.; Russo, Rachel S.; Sive, Barkley C.; Varner, Ruth K.

    2007-05-01

    Average hydroxyl radical (OH) to chlorine atom (Cl·) ratios ranging from 45 to 119 were determined from variability-lifetime relationships for selected nonmethane hydrocarbons (NMHC) in surface air from six different transport sectors arriving at Appledore Island, Maine, during July 2004. Multiplying these ratios by an assumed average OH concentration of 2.5 × 106 cm-3 yielded estimates of Cl· concentrations of 2.2 to 5.6 × 104 cm-3. Summed reaction rates of methane and more than 30 abundant NMHCs with OH and Cl· suggest that Cl· reactions increased the kinetic reactivity of hydrocarbons by 16% to 30% over that due to OH alone in air associated with the various transport sectors. Isoprene and other abundant biogenic alkenes were the most important hydrocarbon contributors after methane to overall kinetic reactivity.

  9. ORGANOCHLORINE CHEMICAL RESIDUES IN HERRING GULLS, RING-BILLED GULLS, AND COMMON TERNS OF WESTERN LAKE SUPERIOR

    EPA Science Inventory

    Residues of polychlorinated biphenyls (PCBs), DDE, DDT, and hexachlorobenzene (HCB) were analyzed for three age classes (e.g. pre-fledge muscle and blood, and post-fledge muscle) of the herring gull, ring-billed gull, and common tern for samples collected in the western end of La...

  10. Assessing gull abundance and food availability in urban parking lots

    USGS Publications Warehouse

    Clark, Daniel E.; Whitney, Jillian J.; MacKenzie, Kenneth G.; Koenen, Kiana K. G.; DeStefano, Stephen

    2015-01-01

    Feeding birds is a common activity throughout the world; yet, little is known about the extent of feeding gulls in urban areas. We monitored 8 parking lots in central Massachusetts, USA, during the fall and winter of 2011 to 2013 in 4 monitoring sessions to document the number of gulls present, the frequency of human–gull feeding interactions, and the effectiveness of signage and direct interaction in reducing human-provisioned food. Parking lots were divided between “education” and “no-education” lots. In education lots, we erected signs about problems caused when people feed birds and also asked people to stop feeding birds. We did not erect signs or ask people to stop feeding birds at no-education lots. We spent >1,200 hours in parking lots (range = 136 to 200 hours per parking lot), and gulls were counted every 20 minutes. We conducted >4,000 counts, and ring-billed gulls (Lorus delawarensis) accounted for 98% of all gulls. Our educational efforts were minimally effective. There were fewer feedings (P = 0.01) in education lots during one of the monitoring sessions but significantly more gulls (P = 0.008) in education lots during 2 monitoring sessions. While there was a marginal decrease (P = 0.055) in the number of feedings after no-education lots were transformed into education lots, there was no difference in gull numbers in these lots (P = 0.16). Education appears to have some influence in reducing the number of people feeding gulls, but our efforts were not able to reduce the number of human feeders or the amount of food enough to influence the number of gulls using parking lots.

  11. Habitat Suitability Index Models: Laughing Gull

    USGS Publications Warehouse

    Zale, Alexander V.; Mulholland, Rosemarie

    1985-01-01

    A review and synthesis of existing information were used to develop a habitat model for laughing gull (Larus atricilla). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1.0 (optimally suitable habitat) for areas along the Gulf of Mexico coast. Habitat suitability indices are designed for use with the Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for application of the model and techniques for measuring model variables are described.

  12. Aerodynamic implications of gull's drooped wing-tips.

    PubMed

    Andrews, S A; Perez, R E; Allan, W D E

    2013-12-01

    When in gliding flight, gulls are observed to adopt a drooped wing-tip configuration. This paper investigates whether this configuration might represent an aerodynamic optimum or if it is the result of constraints imposed by the gull's anatomy. A computational model was developed for the aerodynamic performance of a gull in gliding flight. This model was used in conjunction with both global and local optimizers to determine the most aerodynamically optimal configuration for cases where the gull was constrained to move its wing within its natural flapping cycle as well as when the wing had full freedom of motion. The results of this analysis determined the best wing configuration for a gull in gliding flight and demonstrated that such a configuration not only had the highest lift-to-drag ratio but also could be achieved within the constraints of the kinematics of the gull wing. These results are of interest outside studies of gulls, since the drooped wing-tip configuration could be relevant for new designs of small air vehicles. PMID:24106263

  13. 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.

  14. At–Sea Behavior Varies with Lunar Phase in a Nocturnal Pelagic Seabird, the Swallow-Tailed Gull

    PubMed Central

    Cruz, Sebastian M.; Hooten, Mevin; Huyvaert, Kathryn P.; Proaño, Carolina B.; Anderson, David J.; Afanasyev, Vsevolod; Wikelski, Martin

    2013-01-01

    Strong and predictable environmental variability can reward flexible behaviors among animals. We used long-term records of activity data that cover several lunar cycles to investigate whether behavior at-sea of swallow-tailed gulls Creagrus furcatus, a nocturnal pelagic seabird, varied with lunar phase in the Galápagos Islands. A Bayesian hierarchical model showed that nighttime at-sea activity of 37 breeding swallow-tailed gulls was clearly associated with changes in moon phase. Proportion of nighttime spent on water was highest during darker periods of the lunar cycle, coinciding with the cycle of the diel vertical migration (DVM) that brings prey to the sea surface at night. Our data show that at-sea behavior of a tropical seabird can vary with environmental changes, including lunar phase. PMID:23468889

  15. At-sea behavior varies with lunar phase in a nocturnal pelagic seabird, the swallow-tailed gull

    USGS Publications Warehouse

    Cruz, Sebastian M.; Hooten, Mevin; Huyvaert, Kathryn P.; Proaño, Carolina B.; Anderson, David J.; Afanasyev, Vsevolod; Wikelski, Martin

    2013-01-01

    Strong and predictable environmental variability can reward flexible behaviors among animals. We used long-term records of activity data that cover several lunar cycles to investigate whether behavior at-sea of swallow-tailed gulls Creagrus furcatus, a nocturnal pelagic seabird, varied with lunar phase in the Galápagos Islands. A Bayesian hierarchical model showed that nighttime at-sea activity of 37 breeding swallow-tailed gulls was clearly associated with changes in moon phase. Proportion of nighttime spent on water was highest during darker periods of the lunar cycle, coinciding with the cycle of the diel vertical migration (DVM) that brings prey to the sea surface at night. Our data show that at-sea behavior of a tropical seabird can vary with environmental changes, including lunar phase.

  16. Phylogenetic Diversity and Molecular Detection of Bacteria in Gull Feces▿

    PubMed Central

    Lu, Jingrang; Santo Domingo, Jorge W.; Lamendella, Regina; Edge, Thomas; Hill, Stephen

    2008-01-01

    In spite of increasing public health concerns about the potential risks associated with swimming in waters contaminated with waterfowl feces, little is known about the composition of the gut microbial community of aquatic birds. To address this, a gull 16S rRNA gene clone library was developed and analyzed to determine the identities of fecal bacteria. Analysis of 282 16S rRNA gene clones demonstrated that the gull gut bacterial community is mostly composed of populations closely related to Bacilli (37%), Clostridia (17%), Gammaproteobacteria (11%), and Bacteriodetes (1%). Interestingly, a considerable number of sequences (i.e., 26%) were closely related to Catellicoccus marimammalium, a gram-positive, catalase-negative bacterium. To determine the occurrence of C. marimammalium in waterfowl, species-specific 16S rRNA gene PCR and real-time assays were developed and used to test fecal DNA extracts from different bird (n = 13) and mammal (n = 26) species. The results showed that both assays were specific to gull fecal DNA and that C. marimammalium was present in gull fecal samples collected from the five locations in North America (California, Georgia, Ohio, Wisconsin, and Toronto, Canada) tested. Additionally, 48 DNA extracts from waters collected from six sites in southern California, Great Lakes in Michigan, Lake Erie in Ohio, and Lake Ontario in Canada presumed to be impacted with gull feces were positive by the C. marimammalium assay. Due to the widespread presence of this species in gulls and environmental waters contaminated with gull feces, targeting this bacterial species might be useful for detecting gull fecal contamination in waterfowl-impacted waters. PMID:18469128

  17. Phylogenetic diversity and molecular detection of bacteria in gull feces.

    PubMed

    Lu, Jingrang; Santo Domingo, Jorge W; Lamendella, Regina; Edge, Thomas; Hill, Stephen

    2008-07-01

    In spite of increasing public health concerns about the potential risks associated with swimming in waters contaminated with waterfowl feces, little is known about the composition of the gut microbial community of aquatic birds. To address this, a gull 16S rRNA gene clone library was developed and analyzed to determine the identities of fecal bacteria. Analysis of 282 16S rRNA gene clones demonstrated that the gull gut bacterial community is mostly composed of populations closely related to Bacilli (37%), Clostridia (17%), Gammaproteobacteria (11%), and Bacteriodetes (1%). Interestingly, a considerable number of sequences (i.e., 26%) were closely related to Catellicoccus marimammalium, a gram-positive, catalase-negative bacterium. To determine the occurrence of C. marimammalium in waterfowl, species-specific 16S rRNA gene PCR and real-time assays were developed and used to test fecal DNA extracts from different bird (n = 13) and mammal (n = 26) species. The results showed that both assays were specific to gull fecal DNA and that C. marimammalium was present in gull fecal samples collected from the five locations in North America (California, Georgia, Ohio, Wisconsin, and Toronto, Canada) tested. Additionally, 48 DNA extracts from waters collected from six sites in southern California, Great Lakes in Michigan, Lake Erie in Ohio, and Lake Ontario in Canada presumed to be impacted with gull feces were positive by the C. marimammalium assay. Due to the widespread presence of this species in gulls and environmental waters contaminated with gull feces, targeting this bacterial species might be useful for detecting gull fecal contamination in waterfowl-impacted waters. PMID:18469128

  18. Distribution and textural character of surficial sediments, Isles Dernieres to Ship Shoal region, Louisiana

    SciTech Connect

    Williams, S.J.; Circe, R. ); Penland, S. )

    1989-09-01

    Since 1986, the US Geological Survey and the Louisiana Geological Survey have undertaken field studies of the physical processes responsible for the widespread and extremely rapid coastal erosion of Louisiana's barriers along the Mississippi River delta plain coast. The study area encompasses the coastal and inner shelf region from Raccoon Point to Sandy Point and includes a database of 12-m long vibracores, surface grab samples, sidescan sonar, high resolution seismic reflection profiles, and precision hydrographic profiles. This paper presents results in the coastal-shelf sector that includes the Isles Dernieres barrier island chain seaward almost 30 km to Ship Shoal. The surface and near-surface sediments of the region reflect fluvial and nearshore marine origin with pervasive evidence of winnowing and reworking by marine processes associated with frequent tropical storms and the passage of winter cold fronts. Beach sediments are remarkably uniform in grain size (fine quartz sand), except for the often abundant presence of carbonate shell debris, and are generally well to very well sorted. The shoreface and inner shelf are mantled with muddy sands and sandy muds, whereas, Ship Shoal is almost wholly fine quartz sand, similar in many sedimentologic respects to the Isles Dernieres. The results are consistent with the model of coastal evolution, presented in 1988, in which Ship Shoal is the prototypical example of a drowned coastal barrier undergoing submarine reworking and landward migration in pace with the rapid rates of sea level rise and subsidence.

  19. Temporal and spatial variability of ooid sand shoals: Comparison of Mississippian of Kentucky and Quaternary of Bahamas

    SciTech Connect

    Boardman, M.R. )

    1989-08-01

    An examination of the lithology and topography of Andros Island, Bahamas, reveals it is a Pleistocene ooid sand shoal. A comparison with Joulters Cays (a modern ooid sand shoal directly to the north) shows that much of the original depositional topography is preserved through at least one cycle of sea level highstand and lowstand. Both the Pleistocene and the Holocene ooid sand bodies are a few kilometers to tens of kilometers wide. The total vertical relief of a single episode of Quaternary ooid sand deposition is more than 10 m and includes accumulation in tidal channels, shallow flat areas, and eolian dunes. Today, much of Andros Island is within 2 m of present sea level and is the site of a belt several kilometers wide consisting of muddy tidal flat sediments overlying an exposure surface. The site of ooid sand deposition and shoal complex formation is not continuous along shorelines, especially windward margins, but shifts abruptly along the margins of platforms as a result of minor fluctuations of sea level. Thus, it should be expected that ooid sand shoals (ancient and modern) should be in direct lateral and vertical contact with lagoons, tidal flats, and reefs. The Mississippian Slade Formation contains many of the features of Quaternary ooid sand accumulation: abrupt vertical and lateral gradations between oolitic grainstones, packstones, and lime mudstones, vertical relief of individual oolitic sedimentary packages up to 30 m (perhaps with eolian dunes) and numerous exposure surfaces of varying intensities. These characteristics suggest that this formation represents a time of rapid fluctuations of relative sea level and abrupt shifts in the sites of ooid sand shoal complexes.

  20. Holocene sand shoals offshore of the Mississippi River delta plain

    USGS Publications Warehouse

    Penland, Shea; Suter, John R.; McBride, Randolph A.; Williams, S. Jeffress; Kindinger, Jack G.; Boyd, Ron

    1989-01-01

    Collectively, these sand shoals represent a large potential source of aggregate for shoreline restoration and erosion control as well as possible hard mineral resources. Scientifically, these shoals provide insight into the processes which control coastal evolution and shelf sand development under the condition of relative sea level rise.

  1. A pelagic outbreak of avian cholera in North American gulls: Scavenging as a primary mechanism for transmission?

    USGS Publications Warehouse

    Wille, Michelle; McBurney, Scott; Robertson, Gregory J.; Wilhelm, Sabine; Blehert, David; Soos, Catherine; Dunphy, Ron; Whitney, Hugh

    2016-01-01

    Avian cholera, caused by the bacterium Pasteurella multocida, is an endemic disease globally, often causing annual epizootics in North American wild bird populations with thousands of mortalities. From December 2006 to March 2007, an avian cholera outbreak caused mortality in marine birds off the coast of Atlantic Canada, largely centered 300–400 km off the coast of the island of Newfoundland. Scavenging gulls (Larus spp.) were the primary species detected; however, mortality was also identified in Black-legged Kittiwakes (Rissa tridactyla) and one Common Raven (Corvus corax), a nonmarine species. The most common gross necropsy findings in the birds with confirmed avian cholera were acute fibrinous and necrotizing lesions affecting the spleen, air sacs, and pericardium, and nonspecific hepatomegaly and splenomegaly. The etiologic agent, P. multocida serotype 1, was recovered from 77 of 136 carcasses examined, and confirmed or probable avian cholera was diagnosed in 85 cases. Mortality observed in scavenging gull species was disproportionately high relative to their abundance, particularly when compared to nonscavenging species. The presence of feather shafts in the ventricular lumen of the majority of larid carcasses diagnosed with avian cholera suggests scavenging of birds that died from avian cholera as a major mode of transmission. This documentation of an outbreak of avian cholera in a North American pelagic environment affecting primarily scavenging gulls indicates that offshore marine environments may be a component of avian cholera dynamics.

  2. Comparison of Helicobacter spp. genetic sequences in wild and captive seals, and gulls.

    PubMed

    Oxley, Andrew P A; McKay, David B

    2005-06-01

    Helicobacter species are widely distributed in the gastrointestinal system of humans and many animal taxa. Investigations of natural infections are essential to elucidating their role within the host. The feces of fur seals Arctocephalus pusillus doriferus and sea lions Neophoca cinerea from 3 separate captive populations, as well as a wild colony from Kangaroo Island, Australia, were examined for the occurrence of Helicobacter spp. The feces from several wild silver gulls Larus novahollandiae were also investigated. As detected by PCR, 18 of 21 samples from captive and 12 of 16 samples from wild seals were positive for Helicobacter spp. Three species were identified in these animals. Whilst one possibly novel type was identified from wild fur seals, the majority of wild and captive individuals had the same species. This species also occurred in more than 1 seal type and in silver gulls, and shared a 98.1 to 100% identity to other Helicobacter spp. from harp seals and sea otters. A similar sequence type to species identified from cetaceans was also detected in several captive seals. This study reports for the first time the presence of Helicobacter spp. in wild and captive seals and demonstrates the diversity and broad-host range of these organisms in the marine host. PMID:16060262

  3. Distribution of Gull Specific Molecular Marker in Coastal Areas of Lake Ontario

    EPA Science Inventory

    Gulls have been implicated as primary sources of fecal contamination in the Great Lakes, a fact that may have health implications due to the potential spread of microbial pathogens by waterfowl. To better understand the spatial variability of gull fecal contamination, a gull-spe...

  4. Glaucous gull predation of goslings on the Yukon-Kuskokwim Delta, Alaska

    USGS Publications Warehouse

    Bowman, T.D.; Stehn, R.A.; Scribner, K.T.

    2004-01-01

    Glaucous Gulls (Larus hyperboreus) nesting on the Yukon-Kuskokwim (Y-K) Delta frequently prey on juvenile waterfowl. We collected 434 Glaucous Gulls from late June to early August 1994 to examine diet. Identification of undigested prey tissue, based on DNA microsatellite loci, showed three species of goslings in gull stomachs: Emperor Goose (Chen canagica), White-fronted Goose (Anser albifrons), and Cackling Canada Goose (Branta canadensis minima). Gulls that nested inland and were collected > 1.6 km from the coast accounted for approximately 70% of the total gull predation on Emperor and Canada Geese, and 96% on White-fronted Geese. Our stratified sample of gull stomachs and aerial survey estimates of population size and distribution of gulls and juvenile geese enabled extrapolation of species-specific predation rates to the entire Y-K Delta. We estimated that a minimum of 21 000 Emperor Goose, 34 000 Canada Goose, and 16 000 White-fronted Goose goslings were consumed by 12 600 Glaucous Gulls during the brood-rearing period on the Y-K Delta in 1994. Minimum estimated take by gulls represented 33% of Cackling Canada Goose, 47% of Emperor Goose, and 39% of White-fronted Goose eggs estimated to have hatched in the same area as gull collections. Gulls selected the three species of geese approximately in proportion to their abundance. Although gull predation caused significant gosling mortality, its role in regulating goose populations on Y-K Delta remains unresolved.

  5. Does garbage in diet improve Glaucous Gull reproductive output?

    USGS Publications Warehouse

    Powell, Abby N.; Weiser, Emily L.

    2010-01-01

    Anthropogenic subsidies are used by a variety of predators in areas developed for human use or residence. If subsidies promote population growth, these predators can have a negative effect on local prey species. The Glaucous Gull (Larus hyperboreus) is an abundant predator in northern Alaska that is believed to benefit from garbage as a supplemental food source, but this supposition has never been tested. In summer 2008 and 2009, we recorded the Glaucous Gull's diet and reproduction at 10 breeding colonies in northern Alaska. Colonies were in industrial, residential, and undeveloped areas and ranged from 5 to 75 km from the nearest landfill. By colony, garbage occurred in zero to 85% of pellets and food remains produced during the chick-rearing period, and the average number of chicks fledged per pair ranged from zero to 2.9. Random-forest analysis indicated that percent occurrence of garbage in the diet was the second most important factor (after number of eggs per pair) explaining variance in fledging rate. There was a significant positive correlation between percent occurrence of garbage in the diet and fledging rate in each year. If this correlation reflects a causal relationship, it suggests that human development that increases gulls' access to garbage could result in increased local gull populations. Such an increase could affect the gulls' natural prey species, including at least 14 species of shorebirds and waterfowl of conservation concern.

  6. Sexing California gulls using morphometrics and discriminant function analysis

    USGS Publications Warehouse

    Herring, G.; Ackerman, J.T.; Eagles-Smith, C. A.; Takekawa, J.Y.

    2010-01-01

    A discriminant function analysis (DFA) model was developed with DNA sex verification so that external morphology could be used to sex 203 adult California Gulls (Larus californicus) in San Francisco Bay (SFB). The best model was 97% accurate and included head-to-bill length, culmen depth at the gonys, and wing length. Using an iterative process, the model was simplified to a single measurement (head-to-bill length) that still assigned sex correctly 94% of the time. A previous California Gull sex determination model developed for a population in Wyoming was then assessed by fitting SFB California Gull measurement data to the Wyoming model; this new model failed to converge on the same measurements as those originally used by the Wyoming model. Results from the SFB discriminant function model were compared to the Wyoming model results (by using SFB data with the Wyoming model); the SFB model was 7% more accurate for SFB California gulls. The simplified DFA model (head-to-bill length only) provided highly accurate results (94%) and minimized the measurements and time required to accurately sex California Gulls.

  7. Herring gulls and great black-backed gulls as indicators of contaminants in bald eagles in Lake Ontario, Canada.

    PubMed

    Weseloh, D Vaughn; Hughes, Kimberly D; Ewins, Peter J; Best, Dave; Kubiak, Timothy; Shieldcastle, Mark C

    2002-05-01

    In 2000, a pair of bald eagles (Haliaeetus leucocephalus) nested successfully along the shorelines of Lake Ontario in North America for the first time since 1957. However, it is a continuing question whether bald eagles will be able to reproduce successfully as they return to nest on Lake Ontario. Great black-backed gulls (Larus marinus) and herring gulls (L. argentatus) were selected as surrogate species to predict contaminant levels in eggs of bald eagles nesting on Lake Ontario. Because of the suspected overlap in the diets of great black-backed gulls and bald eagles (i.e., fish, gull chicks, and waterfowl), the two species probably occupy a similar trophic level in the Lake Ontario food web and, thus, may have similar contaminant levels. Fresh great black-backed gull and herring gull eggs were collected from three study sites in eastern Lake Ontario in 1993 and 1994 and analyzed for contaminants. Average contaminant levels of dichlorodiphenyldichloroethane (p,p'-DDE), total polychlorinated biphenyls (PCBs), and dieldrin in great black-backed gull eggs were 12.85, 26.27, and 0.27 microg/g, respectively. The mean ratio of contaminant levels in great black-backed gull eggs to contaminant levels in herring gull eggs for these three contaminants was 2.09 (range of means, 1.73-2.38). Predicted levels of contaminants in bald eagle eggs in Lake Ontario would be expected to be similar to the mean levels reported for great black-backed gull eggs. As a comparison, contaminant levels in bald eagle eggs collected from other Great Lakes nesting sites were compared to mean levels reported for herring gull eggs collected from nearby sites in 1986 to 1995. The mean ratio of contaminant levels in bald eagle eggs to contaminant levels in herring gull eggs from these sites for DDE, total PCBs, and dieldrin was 2.40 (range of means, 1.73-3.28). These ratios are very similar to those reported using great black-backed gull eggs, illustrating the apparent similarity in trophic status

  8. GPS tracking data of Lesser Black-backed Gulls and Herring Gulls breeding at the southern North Sea coast

    PubMed Central

    Stienen, Eric W.M.; Desmet, Peter; Aelterman, Bart; Courtens, Wouter; Feys, Simon; Vanermen, Nicolas; Verstraete, Hilbran; de Walle, Marc Van; Deneudt, Klaas; Hernandez, Francisco; Houthoofdt, Robin; Vanhoorne, Bart; Bouten, Willem; Buijs, Roland-Jan; Kavelaars, Marwa M.; Müller, Wendt; Herman, David; Matheve, Hans; Sotillo, Alejandro; Lens, Luc

    2016-01-01

    Abstract In this data paper, Bird tracking - GPS tracking of Lesser Black-backed Gulls and Herring Gulls breeding at the southern North Sea coast is described, a species occurrence dataset published by the Research Institute for Nature and Forest (INBO). The dataset (version 5.5) contains close to 2.5 million occurrences, recorded by 101 GPS trackers mounted on 75 Lesser Black-backed Gulls and 26 Herring Gulls breeding at the Belgian and Dutch coast. The trackers were developed by the University of Amsterdam Bird Tracking System (UvA-BiTS, http://www.uva-bits.nl). These automatically record and transmit bird movements, which allows us and others to study their habitat use and migration behaviour in great detail. Our bird tracking network is operational since 2013. It is funded for LifeWatch by the Hercules Foundation and maintained in collaboration with UvA-BiTS and the Flanders Marine Institute (VLIZ). The recorded data are periodically released in bulk as open data (http://dataset.inbo.be/bird-tracking-gull-occurrences), and are also accessible through CartoDB and the Global Biodiversity Information Facility (GBIF). PMID:26877689

  9. Cytochrome P4501A induction and DNA adduct formation in glaucous gulls (Larus hyperboreus), fed with environmentally contaminated gull eggs.

    PubMed

    Østby, Lene; Gabrielsen, Geir Wing; Krøkje, Ase

    2005-11-01

    This study indicates that complex mixtures of pollutants found in the Arctic marine environment have genotoxic effects in glaucous gulls (Larus hyperboreus). DNA adducts were quantified, by the (32)P-postlabeling technique, in liver samples from gulls fed with hen eggs (controls) and from gulls fed with environmentally contaminated gull eggs (exposed). All birds were grown and fed under laboratory conditions. Hepatic homologues to mammalian cytochrome P4501A (CYP1A) proteins were also determined by Western blotting. DNA adducts were detected in all but one liver sample, but the exposed birds had a significantly increased level of DNA adducts relative to that of the controls. There was no clear significant correlation between the DNA adduct level and the level of organochlorine compounds (OCs) in blood. The level of CYP1A protein was significantly higher in the liver of exposed male gulls than in the liver of control males and positively correlated, with significance, to the level of OC compounds measured in blood. There was no significant correlation between the level of DNA adducts and the CYP1A protein content. PMID:16216630

  10. GPS tracking data of Lesser Black-backed Gulls and Herring Gulls breeding at the southern North Sea coast.

    PubMed

    Stienen, Eric W M; Desmet, Peter; Aelterman, Bart; Courtens, Wouter; Feys, Simon; Vanermen, Nicolas; Verstraete, Hilbran; de Walle, Marc Van; Deneudt, Klaas; Hernandez, Francisco; Houthoofdt, Robin; Vanhoorne, Bart; Bouten, Willem; Buijs, Roland-Jan; Kavelaars, Marwa M; Müller, Wendt; Herman, David; Matheve, Hans; Sotillo, Alejandro; Lens, Luc

    2016-01-01

    In this data paper, Bird tracking - GPS tracking of Lesser Black-backed Gulls and Herring Gulls breeding at the southern North Sea coast is described, a species occurrence dataset published by the Research Institute for Nature and Forest (INBO). The dataset (version 5.5) contains close to 2.5 million occurrences, recorded by 101 GPS trackers mounted on 75 Lesser Black-backed Gulls and 26 Herring Gulls breeding at the Belgian and Dutch coast. The trackers were developed by the University of Amsterdam Bird Tracking System (UvA-BiTS, http://www.uva-bits.nl). These automatically record and transmit bird movements, which allows us and others to study their habitat use and migration behaviour in great detail. Our bird tracking network is operational since 2013. It is funded for LifeWatch by the Hercules Foundation and maintained in collaboration with UvA-BiTS and the Flanders Marine Institute (VLIZ). The recorded data are periodically released in bulk as open data (http://dataset.inbo.be/bird-tracking-gull-occurrences), and are also accessible through CartoDB and the Global Biodiversity Information Facility (GBIF). PMID:26877689

  11. Long-term morphological response to dredging including cut-across-shoal in a tidal channel-shoal system

    NASA Astrophysics Data System (ADS)

    Wang, Yu-Hai; Wang, Chong-Hao; Tang, Li-Qun; Liu, Da-Bin; Guo, Chuan-Sheng; Liu, Chun-Jing; Zhao, Hui-Ming

    2014-12-01

    This study examines long-term channel-shoal stability in the Tieshan Bay, which is located on the southwest coast of China. A large-scale channel-shoal system has historically existed in the outer Tieshan Bay. A navigation waterway is initiated by cutting and dredging a mid-channel shoal to supply coal to a power plant on the middle coast of the Tieshan Bay. Dredging of the access channel to the Tieshan Port was conducted in two stages followed by land reclamation. It is thus of practical meaning to explore how the channel-shoal system will evolve in long term afterwards. This study uses the process-based finite-volume coastal ocean model (FVCOM) to investigate long-term (centennial) morphological evolution of the channel-shoal system. After well calibration of hydrodynamics and sediment transport, the model forecasts morphodynamic evolution in hundred years. The simulations show that continuous erosion in tidal channels and accretion over shoals and intertidal flats occur. However, the cutting and access channels will be subjected to long-term siltation. A secondary channel indicating the reorientation of the access channel will emerge, and a localized channel-ridge system at the junction of the major channels will be formed. The overall erosion/accretion pattern demonstrates the combined effect of bottom friction and advective sediment transport processes to be responsible for the channel-shoal formation. Dredging of the tidal channels will stimulate the stability of the channel-shoal pattern. It suggests that the navigation waterway should be set up following the long-term morphological evolution of the channel-shoal system at a design stage and maintenance dredging volume might thus be minimized.

  12. Aspects of hatching success and chick survival in Gull-billed Terns in coastal Virginia

    USGS Publications Warehouse

    Eyler, T.B.; Erwin, R.M.; Stotts, D.B.; Hatfield, J.S.

    1999-01-01

    Because of a long-term population decline in Gull-billed Terns (Sterna nilotica) nesting along the coast of Virginia, we began a three year study in 1994 to monitor hatching success and survival of Gull-billed Tern chicks at several Virginia colony sites. Colonies were located on either small, storm-deposited shellpiles along marsh fringes or large, sandshell overwash fans of barrier islands. Nests were monitored one to three times a week for hatching success, and enclosures were installed around selected nests to monitor chick survival from hatching to about two weeks of age. Hatching success was lower in marsh colonies than island colonies, and was lower in 1995 than in 1994 and 1996, primarily because of flooding. The average brood size of nests where at least one chick hatched was 1.99 chicks. Survival rates of chicks to 14 days depended on hatch order and year but not brood size (one vs. two or more) or time of season. A-chicks had higher survival rates than B-chicks and third-hatched C-chicks (0.661 compared to 0.442 and 0.357, respectively). The year effect was significant only for A-chicks, with lower survival in 1994 (0.50) than in 1995 (0.765) or 1996 (0.758). Overall, productivity was low (0.53 chick per nest) compared to estimates for colonies in Denmark, and was attributable to nest flooding by spring and storm-driven high tides and chick predation, presumably mostly by Great Horned Owls (Bubo virginianus).

  13. Shoaling of nonlinear internal waves in Massachusetts Bay

    USGS Publications Warehouse

    Scotti, A.; Beardsley, R.C.; Butman, B.; Pineda, J.

    2008-01-01

    The shoaling of the nonlinear internal tide in Massachusetts Bay is studied with a fully nonlinear and nonhydrostatic model. The results are compared with current and temperature observations obtained during the August 1998 Massachusetts Bay Internal Wave Experiment and observations from a shorter experiment which took place in September 2001. The model shows how the approaching nonlinear undular bore interacts strongly with a shoaling bottom, offshore of where KdV theory predicts polarity switching should occur. It is shown that the shoaling process is dominated by nonlinearity, and the model results are interpreted with the aid of a two-layer nonlinear but hydrostatic model. After interacting with the shoaling bottom, the undular bore emerges on the shallow shelf inshore of the 30-m isobath as a nonlinear internal tide with a range of possible shapes, all of which are found in the available observational record. Copyright 2008 by the American Geophysical Union.

  14. [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

  15. POTENTIAL FOR GULLS TO TRANSPORT BACTERIA FROM HUMAN WASTE SITES

    EPA Science Inventory

    This study was designed as a first step in assessing whether gulls visiting human waste sites can acquire human microorganisms and distribute them across the coastal landscape. Beaches, landfills, and a lagoon of treated wastewater located in a coastal Lake Michigan county were t...

  16. Phylogenetic Diversity and Molecular Detection of Bacteria in Gull Feces

    EPA Science Inventory

    In spite of increasing public health concerns about the potential risks associated with swimming in waters contaminated with waterfowl feces, little is known about the composition of the gut microbial community of aquatic birds. To address this, a gull 16S rDNA fecal clone librar...

  17. The herring gull complex is not a ring species.

    PubMed Central

    Liebers, Dorit; de Knijff, Peter; Helbig, Andreas J.

    2004-01-01

    Under what circumstances speciation in sexually reproducing animals can occur without geographical disjunction is still controversial. According to the ring-species model, a reproductive barrier may arise through 'isolation by distance' when peripheral populations of a species meet after expanding around some uninhabitable barrier. The classical example of this kind of speciation is the herring gull (Larus argentatus) complex, with a circumpolar distribution in the Northern Hemisphere. Based on mitochondrial DNA variation among 21 gull taxa, we show that members of this complex differentiated largely in allopatry following multiple vicariance and long-distance-colonization events, not primarily through isolation by distance. Reproductive isolation evolved more rapidly between some lineages than between others, irrespective of their genetic distance. Extant taxa are the result of divergent as well as reticulate evolution between two ancestral lineages originally separated in a North Atlantic refugium and a continental Eurasian refugium, respectively. Continental birds expanded along the entire north Eurasian coast and via Beringia into North America. Contrary to the ring-species model, we find no genetic evidence for a closure of the circumpolar ring through colonization of Europe by North American herring gulls. However, closure of the ring in the opposite direction may be imminent, with lesser black-backed gulls about to colonize North America. PMID:15255043

  18. Combined effects of flow condition and parasitism on shoaling behaviour of female guppies Poecilia reticulata.

    PubMed

    Hockley, F A; Wilson, C A M E; Graham, N; Cable, J

    2014-01-01

    Group living in fish can provide benefits of protection from predators and some parasites, more efficient foraging for food, increased mating opportunities and enhanced energetic benefit when swimming. For riverine species, shoaling behaviour can be influenced by various environmental stressors, yet little is known how flow rate might influence the shoaling of diseased fish shoals. In view of the increasingly unpredictable flow rates in streams and rivers, this study aimed to assess the combined effect of flow condition and parasitism on the shoaling behaviour of a model fish species. Shoal size, shoal cohesion and time spent shoaling of female guppies Poecilia reticulata were compared when infected with the directly transmitted ectoparasite Gyrodactylus turnbulli under flow and static conditions. Flow condition was an important factor in influencing shoaling behaviour of guppies with the fish forming larger shoals in the absence of flow. When a shoal member was infected with G. turnbulli, shoal cohesion was reduced, but the magnitude of this effect was dependent on flow condition. In both flow and static conditions, bigger fish formed larger shoals than smaller counterparts. Future changes to stream hydrology with more frequent flooding and drought events will affect the shoaling tendency of fish. During high-flow events, diseased fish may not be able to keep up with shoal mates and therefore have a higher risk of predation. Additionally, these findings may be important for aquaria and farmed species where an increase in flow rate may reduce aggregation in fish. PMID:25152559

  19. Sea-floor character and sedimentary processes of Great Round Shoal Channel, offshore Massachusetts

    USGS Publications Warehouse

    Poppe, Lawrence J.; Ackerman, Seth D.; Foster, David S.; Blackwood, Dann S.; Williams, S. Jeffress; Moser, M.S.; Stewart, H.F.; Glomb, K.A.

    2007-01-01

    The imagery, interpretive data layers, and data presented herein were derived from multibeam echo-sounder and sidescan-sonar data collected in the vicinity of Great Round Shoal Channel, the main passage through shoals located at the eastern entrance to Nantucket Sound, Massachusetts, and from the stations occupied to verify these acoustic data (fig. 1). Basic data layers show sea-floor topography, sun-illuminated shaded relief, and backscatter intensity; interpretive layers show the distributions of surficial sediment, sedimentary environments, and sea-floor features. Presented verification data include sediment grain-size analyses and a gallery of still photographs of the seabed. The multibeam and sidescan data, which together cover an approximately 39.9-km² area of sea floor, were collected during National Oceanic and Atmospheric Administration (NOAA) hydrographic survey H11079 (fig. 1). Although originally collected for charting purposes, these data provide a fundamental framework for research and management activities along this part of the Massachusetts coastline (Noji and others, 2004), show the composition and terrain of the seabed, and provide information on sediment transport and benthic habitat. This publication is the third in a series of U.S. Geological Survey (USGS) digital reports describing the sea-floor geology around Cape Cod. The first focused on the area off the eastern shore of the outer Cape (Poppe and others, 2006); the second on a passage through the Elizabeth Islands (Poppe and others, 2007).

  20. Comparison of Gull Feces-Specific Assays Targeting the 16S rRNA Genes of Catellicoccus marimammalium and Streptococcus spp.

    PubMed Central

    Ryu, Hodon; Griffith, John F.; Khan, Izhar U. H.; Hill, Stephen; Edge, Thomas A.; Toledo-Hernandez, Carlos; Gonzalez-Nieves, Joel

    2012-01-01

    Two novel gull-specific quantitative PCR (qPCR) assays were developed using 16S rRNA gene sequences from gull fecal clone libraries: a SYBR green assay targeting Streptococcus spp. (gull3) and a hydrolysis TaqMan assay targeting Catellicoccus marimammalium (gull4). The objectives of this study were to compare the host specificity of a previous C. marimammalium qPCR assay (gull2) with that of the new markers and to examine the presence of the three gull markers in environmental water samples from different geographic locations. Most of the gull fecal samples tested (n = 255) generated positive signals with the gull2 and gull4 assays (i.e., >86%), whereas only 28% were positive with gull3. Low prevalence and abundance of tested gull markers (0.6 to 15%) were observed in fecal samples from six nonavian species (n = 180 fecal samples), whereas the assays cross-reacted to some extent (13 to 31%) with other (nongull) avian fecal samples. The gull3 assay was positive against fecal samples from 11 of 15 avian species, including gull. Of the presumed gull-impacted water samples (n = 349), 86%, 59%, and 91% were positive with the gull2, the gull3, and the gull4 assays, respectively. Approximately 5% of 239 non-gull-impacted water samples were positive with the gull2 and the gull4 assays, whereas 21% were positive witg the gull3 assay. While the relatively high occurrence of gull2 and gull4 markers in waters impacted by gull feces suggests that these assays could be used in environmental monitoring studies, the data also suggest that multiple avian-specific assays will be needed to accurately assess the contribution of different avian sources in recreational waters. PMID:22226950

  1. Comparison of gull feces-specific assays targeting the 16S rRNA genes of Catellicoccus marimammalium and Streptococcus spp.

    PubMed

    Ryu, Hodon; Griffith, John F; Khan, Izhar U H; Hill, Stephen; Edge, Thomas A; Toledo-Hernandez, Carlos; Gonzalez-Nieves, Joel; Santo Domingo, Jorge

    2012-03-01

    Two novel gull-specific quantitative PCR (qPCR) assays were developed using 16S rRNA gene sequences from gull fecal clone libraries: a SYBR green assay targeting Streptococcus spp. (gull3) and a hydrolysis TaqMan assay targeting Catellicoccus marimammalium (gull4). The objectives of this study were to compare the host specificity of a previous C. marimammalium qPCR assay (gull2) with that of the new markers and to examine the presence of the three gull markers in environmental water samples from different geographic locations. Most of the gull fecal samples tested (n = 255) generated positive signals with the gull2 and gull4 assays (i.e., >86%), whereas only 28% were positive with gull3. Low prevalence and abundance of tested gull markers (0.6 to 15%) were observed in fecal samples from six nonavian species (n = 180 fecal samples), whereas the assays cross-reacted to some extent (13 to 31%) with other (nongull) avian fecal samples. The gull3 assay was positive against fecal samples from 11 of 15 avian species, including gull. Of the presumed gull-impacted water samples (n = 349), 86%, 59%, and 91% were positive with the gull2, the gull3, and the gull4 assays, respectively. Approximately 5% of 239 non-gull-impacted water samples were positive with the gull2 and the gull4 assays, whereas 21% were positive witg the gull3 assay. While the relatively high occurrence of gull2 and gull4 markers in waters impacted by gull feces suggests that these assays could be used in environmental monitoring studies, the data also suggest that multiple avian-specific assays will be needed to accurately assess the contribution of different avian sources in recreational waters. PMID:22226950

  2. [Hematologic and hematochemical characteristics of the herring gull (Larus argentatus) and the buzzard (Buteo buteo)].

    PubMed

    Bini, P P; Floris, B; Nuvole, P; Pau, S; Zedda, M T

    1989-09-01

    Some hematological and hematochemical parameters in eight herring gulls (Larus argentatus) and in six buzzards (Buteo buteo) were checked. The buzzards were fed with ovine meat exclusively, while the herring gulls were fed with fish and ovine meat. Considerable differences between the two species were noted, particularly as far as the hematological and lipidic parameters are concerned. These differences are probably related to the aquatic life of the herring gull. PMID:2627341

  3. Seafloor character and sedimentary processes in eastern Long Island Sound and western Block Island Sound

    NASA Astrophysics Data System (ADS)

    Poppe, L. J.; Digiacomo-Cohen, M. L.; Smith, S. M.; Stewart, H. F.; Forfinski, N. A.

    2006-06-01

    Multibeam bathymetric data and seismic-reflection profiles collected in eastern Long Island Sound and western Block Island Sound reveal previously unrecognized glacial features and modern bedforms. Glacial features include an ice-sculptured bedrock surface, a newly identified recessional moraine, exposed glaciolacustrine sediments, and remnants of stagnant-ice-contact deposits. Modern bedforms include fields of transverse sand waves, barchanoid waves, giant scour depressions, and pockmarks. Bedform asymmetry and scour around obstructions indicate that net sediment transport is westward across the northern part of the study area near Fishers Island, and eastward across the southern part near Great Gull Island.

  4. Genetic affinities within the herring gull Larus argentatus assemblage revealed by AFLP genotyping.

    PubMed

    de Knijff P; Denkers, F; van Swelm, N D; Kuiper, M

    2001-01-01

    To date, the taxonomic status of circumpolar breeding populations of the Herring Gull Larus argentatus, the Lesser Black-backed Gull Larus fuscus, and the closely related Yellow-legged Gull Larus cachinnans has been based on differences or similarities in phenotype, morphology, and feeding and premating behavior. To shed some new light on the many taxonomic uncertainties surrounding these taxa, we describe the results of a large DNA study based on comparing the distribution of 209 biallelic markers among 109 gulls, representing 11 gull taxa of the Herring Gull assemblage and the Common Gull Larus canus. A detailed phylogenetic analysis failed to show clustering of individuals into groups representing either geographic origin or phenotype. Alternatively, birds were grouped into taxa defined on the basis of phenotype and geographic origin or phenotype alone. Genetic analyses revealed significantly different genetic distances between all pairs of taxa. However, based on these genetic distances, again no consistent phylogenetic tree could be constructed. Analysis of molecular variance indicated that about 77% of the total genetic variability among these gulls could be explained by within-taxon differences. Only 23% of the total genetic variability was due to genetic differences between taxa, irrespective of their species or subspecies status. Although this seems to challenge the current taxonomic treatment of the herring gull assemblage, our results are too premature and too incomplete to recommend a drastic change. PMID:11139298

  5. Numerical simulations of shoaling internal solitary waves of elevation

    NASA Astrophysics Data System (ADS)

    Xu, Chengzhu; Subich, Christopher; Stastna, Marek

    2016-07-01

    We present high-resolution, two- and three-dimensional direct numerical simulations of large amplitude internal solitary waves of elevation on the laboratory scale, shoaling onto and over a small-amplitude shelf. The three-dimensional, mapped coordinate, spectral collocation method used for the simulations allows for accurate modelling of both the shoaling waves and the bottom boundary layer. The shoaling of the waves is characterized by the formation of a quasi-trapped core which undergoes a spatially growing stratified shear instability at its edge and a lobe-cleft instability in its nose. Both of these instabilities develop and three-dimensionalize concurrently, leading to strong bottom shear stress. We explore significant regions of Schmidt and Reynolds number space and demonstrate that the formation of shear instabilities during shoaling is robust and should be readily observable in a number of standard laboratory setups. In the experiments with a corrugated bottom boundary, boundary layer separation is found inside each of the corrugations during shoaling. This more complex boundary layer phenomenology precludes the formation of the lobe-cleft instability almost completely and hence provides a different mechanism for fluid and material exchange across the bottom boundary layer. Our analyses suggest that all of these wave-induced instabilities can lead to enhanced turbulence in the water column and increased shear stress on the bottom boundary. Through the generation and evolution of these instabilities, the shoaling of internal solitary waves of elevation is likely to provide systematic mechanisms for material mixing, cross-boundary layer transport, and sediment resuspension.

  6. Sleeping gulls monitor the vigilance behaviour of their neighbours

    PubMed Central

    Beauchamp, Guy

    2008-01-01

    Individuals in groups are often thought to scan their surroundings for threats independently of one another. Models, however, suggest that foragers should monitor the vigilance level of their neighbours to prevent cheating, and to gather information about incipient predation risk. Evidence for monitoring of vigilance is scant. Here, I examined changes in vigilance levels in sleeping gulls (Larus sp.) surrounded by neighbours in various states of alertness. Controlling for group size and neighbour density, gulls interrupted sleep more often to scan their surroundings, and were therefore more vigilant, when their neighbours were alert rather than sleeping or preening. The results provide evidence for copying of vigilance within groups of birds, suggesting a complex flow of information about predation risk in groups. PMID:18940772

  7. DNA fingerprinting reveals elevated mutation rates in herring gulls inhabiting a genotoxically contaminated site

    SciTech Connect

    Yauk, C.L.; Quinn, J.S.

    1995-12-31

    The authors used multi-locus DNA fingerprinting to examine families of herring gulls (Larus argentatus) from a genotoxically contaminated site (Hamilton Harbour) and from a pristine location (Kent Island, Bay of Fundy) to show significant differences in mutation rates between the locations. Overall the authors identified 17 mutant bands from 15 individuals of the 35 examined from Hamilton Harbour, and 7 mutant fragments from 7 individuals, of the 43 examined from Kent Island; a mutation frequency of 0.429 per nestling for Hamilton Harbour and 0.163 for Kent Island. The total number of individuals with mutant bands was significantly higher at Hamilton Harbour than at Kent Island (X{sup 2}=6.734; df = 1; P < 0.01). Ongoing analysis of other less contaminated sites also reveals lower mutation rates than those seen in Hamilton Harbour. With multi-locus DNA fingerprinting many regions of the genome can be surveyed simultaneously. The tandemly repeated arrays of nucleotides examined with DNA fingerprinting are known to have elevated rates of mutation. Furthermore, the mutations seen with DNA fingerprinting are predominantly heritable. Other biomarkers currently used in situ are not able to monitor direct and heritable DNA mutation, or measure biological endpoints that frequently result in spontaneous abortion creating difficulty in observing significantly elevated levels in viable offspring. The authors suggest that multilocus DNA fingerprinting can be used as a biomarker to identify potentially heritable risks before the onset of other types of ecological damage. This approach provides a direct measure of mutation in situ and in vivo in a vertebrate species under ambient conditions.

  8. True navigation in migrating gulls requires intact olfactory nerves.

    PubMed

    Wikelski, Martin; Arriero, Elena; Gagliardo, Anna; Holland, Richard A; Huttunen, Markku J; Juvaste, Risto; Mueller, Inge; Tertitski, Grigori; Thorup, Kasper; Wild, Martin; Alanko, Markku; Bairlein, Franz; Cherenkov, Alexander; Cameron, Alison; Flatz, Reinhard; Hannila, Juhani; Hüppop, Ommo; Kangasniemi, Markku; Kranstauber, Bart; Penttinen, Maija-Liisa; Safi, Kamran; Semashko, Vladimir; Schmid, Heidi; Wistbacka, Ralf

    2015-01-01

    During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to < 5°N) to sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080 km) or eastward (885 km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances. PMID:26597351

  9. True navigation in migrating gulls requires intact olfactory nerves

    PubMed Central

    Wikelski, Martin; Arriero, Elena; Gagliardo, Anna; Holland, Richard A.; Huttunen, Markku J.; Juvaste, Risto; Mueller, Inge; Tertitski, Grigori; Thorup, Kasper; Wild, Martin; Alanko, Markku; Bairlein, Franz; Cherenkov, Alexander; Cameron, Alison; Flatz, Reinhard; Hannila, Juhani; Hüppop, Ommo; Kangasniemi, Markku; Kranstauber, Bart; Penttinen, Maija-Liisa; Safi, Kamran; Semashko, Vladimir; Schmid, Heidi; Wistbacka, Ralf

    2015-01-01

    During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to < 5°N) to sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080 km) or eastward (885 km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances. PMID:26597351

  10. Use of a nesting platform by Gull-billed Terns and Black Skimmers at the Salton Sea, California

    USGS Publications Warehouse

    Molina, K.C.; Ricca, M.A.; Miles, A.K.; Schoneman, C.

    2009-01-01

    In 2006, we constructed an elevated nesting platform at the Salton Sea, California, and monitored its use by Gull-billed Terns and Black Skimmers over three subsequent breeding seasons. Black Skimmers were the first to colonize the platform with a total of five nests in 2006. In 2007 Gull-billed Terns colonized the platform with a total of 28 nests and the number of Black Skimmer nests increased to 20. Neither species nested on the platform in 2008. Low success for both species was probably influenced by at least two factors. First, when both species nested on the platform, nest densities were higher than is typical of their colonies on larger, earthen islands, and colony success may have been reduced by overcrowding. Second, lack of access to water may have reduced chicks' ability to thermoregulate effectively in the hot environment of the Salton Sea. Refinements to the size, design, and location of artificial nesting habitats are necessary to enhance productivity of colonial groundnesting birds at the Salton Sea successfully.

  11. Species differences in total mercury concentration in gulls from the Gulf of Gdansk (Southern Baltic).

    PubMed

    Szumiło-Pilarska, Emilia; Grajewska, Agnieszka; Falkowska, Lucyna; Hajdrych, Julia; Meissner, Włodzimierz; Frączek, Tomasz; Bełdowska, Magdalena; Bzoma, Szymon

    2016-01-01

    Aquatic birds occupy a high position in the trophic pyramid of the Baltic Sea. This means that they accumulate the greatest amount of harmful substances, including mercury, in their bodies. This element penetrates into their systems mainly via the alimentary canal. The amount of mercury absorbed from food depends on how badly the environment is polluted with this metal. The aim of this study was to discover the concentrations of total mercury (HgT) in the contour feathers, muscles, brain, lungs, liver, kidneys, heart and blood of four gull species Herring Gull (Larus argentatus), Common Gull (Larus canus), Black-headed Gull (Larus ridibundus) and Great Black-backed Gull (Larus marinus) and organic mercury (Hgorg) in the liver and brain of Herring Gull. The most important characteristic of the results obtained for the studied gulls was the statistically significant differences between the four species, probably resulting from their different diets-confirmed by stable-isotopes analysis (δ(15)N and δ(13)C). A logarithmic dependence was found between HgT in the blood and HgT in the brain of the Herring Gull. The authors suggest that among gulls burdened with the greatest mercury load, it is possible that the brain is protected by higher Hg accumulation in the muscles. The percentage share of Hgorg in the brain and liver of the Herring Gull depended on the concentration of HgT in these tissues and was always higher in the brain. In none of the cases, did the mercury levels assayed in the internal gulls' tissues exceed values associated with adverse health effects. PMID:26653750

  12. Dynamic web cache publishing for IaaS clouds using Shoal

    NASA Astrophysics Data System (ADS)

    Gable, Ian; Chester, Michael; Armstrong, Patrick; Berghaus, Frank; Charbonneau, Andre; Leavett-Brown, Colin; Paterson, Michael; Prior, Robert; Sobie, Randall; Taylor, Ryan

    2014-06-01

    We have developed a highly scalable application, called Shoal, for tracking and utilizing a distributed set of HTTP web caches. Our application uses the Squid HTTP cache. Squid servers advertise their existence to the Shoal server via AMQP messaging by running Shoal Agent. The Shoal server provides a simple REST interface that allows clients to determine their closest Squid cache. Our goal is to dynamically instantiate Squid caches on IaaS clouds in response to client demand. Shoal provides the VMs on IaaS clouds with the location of the nearest dynamically instantiated Squid Cache.

  13. 75 FR 29574 - Final Legislative Environmental Impact Statement for the Harvest of Glaucous-Winged Gull Eggs by...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ... Gull Eggs by the Huna Tlingit in Glacier Bay National Park AGENCY: National Park Service, Interior... Glaucous-Winged Gull Eggs by the Huna Tlingit in Glacier Bay National Park. SUMMARY: The National Park... the harvest of glaucous-winged gull eggs by the Huna Tlingit in Glacier Bay National Park....

  14. Comparison of gull-specific assays targeting 16S rRNA gene of Catellicoccus marimammalium and Streptococcus spp.

    EPA Science Inventory

    Gulls have been implicated as a source of fecal contamination in inland and coastal waters. Only one gull-specific assay is currently available (i.e., gull2 qPCR assay). This assay is based on the 16S rRNA gene of Catellicocclls marimammalium and has showed a high level of host-s...

  15. What`s normal?: Body condition in Great Lakes herring gulls

    SciTech Connect

    Hebert, C.E.; Shutt, J.L.

    1994-12-31

    The Canadian Wildlife Service`s herring gull (Larus argentatus) surveillance program has demonstrated the usefulness of this species as a monitor of spatial and temporal trends in contaminant levels. However, the effects of environmental contaminants on gulls are difficult to distinguish from the effects of other anthropogenic stressors such as the introduction of exotic species, overfishing and habitat loss. To understand the relative importance of these factors in regulating the success of individual gulls and, hence, gull populations, the authors must first have a better understanding of what constitutes a ``normal`` bird. Improving the ability to differentiate between normal and abnormal birds is crucial in any health assessment of Great Lakes gulls. Body condition has been shown to be an important measure of a bird`s ability to provide energy for egg production, migration etc. Numerous approaches have been used to assess condition, most of which required that the bird be sacrificed. In this study, the authors describe a nonlethal technique to quantify body condition in herring gulls. Multivariate statistics are used to quantify body size, relate body size to total mass and from that, determine relative body condition. Initially, body condition is assessed in gulls from a reference colony where reproductive success is normal and anthropogenic influences are limited. This reference population is then used as a baseline against which other gull populations are compared.

  16. Molecular Detection of Campylobacter spp. in California Gull (Larus californicus) Excreta

    EPA Science Inventory

    We examined the prevalence, quantity, and diversity of Campylobacter species in the excreta of 159 California gull samples using PCR and qPCR based detection assays. While Campylobacter prevalence and abundance was relatively high in the gull excreta examined, molecular data ind...

  17. Newly discovered methoxylated polybrominated diphenoxybenzenes have been contaminants in the Great Lakes herring gull eggs for thirty years.

    PubMed

    Chen, Da; Letcher, Robert J; Gauthier, Lewis T; Chu, Shaogang; McCrindle, Robert

    2012-09-01

    We recently reported the discovery and identification of novel methoxylated polybrominated diphenoxybenzenes (MeO-PBDPBs) in herring gulls eggs from the Laurentian Great Lakes of North America. We presently investigated the temporal changes (1982-2010) in MeO-PBDPB concentrations and congener patterns, as well as chemical tracers of diet (ratios of carbon and nitrogen stable isotopes), in egg pool homogenates from five selected colony sites across the Great Lakes. Egg pool homogenates from the Channel-Shelter (C-S) Island (Lake Huron) contained ∑MeO-PBDPB concentrations orders of magnitude greater than those from other colonies, suggesting potential point contamination sources nearby. In the C-S Island egg pools, concentrations increased from the initial study year (31 ng/g wet weight) and peaked around the late 1990s, followed by a general decline until 2010. Over the period, concentrations generally increased in eggs from Fighting Island (Lake Erie), Toronto Harbour (Lake Ontario) and Big Sister Island (Lake Michigan) colonies, whereas the levels in Agawa Rock (Lake Superior) declined. Although other factors likely exist, changes over time in the carbon and nitrogen isotope tracers reflected a shift of the gull diet from aquatic to more terrestrial origins, and suggested this diet shift partially accounted for the temporal changes of ∑MeO-PBDPB levels in eggs from most colonies. The ratio of Br(6)- to Br(5)-MeO-PBDPB congeners generally decreased over time in the colonies at Channel-Shelter Island, Fighting Island and Agawa Rock. This suggested that Br(5)- versus Br(6)-MeO-PBDPB congeners and/or possibly their nonmethoxylated and higher brominated precursors may have been more abundant in diets of terrestrial origin. Notably, these MeO-PBDPB congeners are not "emerging" brominated substances, but rather "recently discovered" contaminants since, as of 2011, ∑MeO-PBDPB concentrations have been constantly in the range of 30-100 ng/g ww for at least the last 30

  18. Comparison of Gull Feces-specific Assays Targeting the 16S rRNA Gene of Catellicoccus Marimammalium and Streptococcus spp.

    EPA Science Inventory

    Two novel gull-specific qPCR assays were developed using 16S rRNA gene sequences from gull fecal clone libraries: a SYBR-green-based assay targeting Streptococcus spp. (i.e., gull3) and a TaqMan qPCR assay targeting Catellicoccus marimammalium (i.e., gull4). The main objectives ...

  19. The Efficiency of an Integrated Program Using Falconry to Deter Gulls from Landfills.

    PubMed

    Thiériot, Ericka; Patenaude-Monette, Martin; Molina, Pierre; Giroux, Jean-François

    2015-01-01

    Gulls are commonly attracted to landfills, and managers are often required to implement cost-effective and socially accepted deterrence programs. Our objective was to evaluate the effectiveness of an intensive program that integrated the use of trained birds of prey, pyrotechnics, and playback of gull distress calls at a landfill located close to a large ring-billed gull (Larus delawarensis) colony near Montreal, Quebec, Canada. We used long-term survey data on bird use of the landfill, conducted behavioral observations of gulls during one season and tracked birds fitted with GPS data loggers. We also carried out observations at another landfill located farther from the colony, where less refuse was brought and where a limited culling program was conducted. The integrated program based on falconry resulted in a 98% decrease in the annual total number of gulls counted each day between 1995 and 2014. A separate study indicated that the local breeding population of ring-billed gulls increased and then declined during this period but remained relatively large. In 2010, there was an average (±SE) of 59 ± 15 gulls/day using the site with falconry and only 0.4% ± 0.2% of these birds were feeding. At the other site, there was an average of 347 ± 55 gulls/day and 13% ± 3% were feeding. Twenty-two gulls tracked from the colony made 41 trips towards the landfills: twenty-five percent of the trips that passed by the site with falconry resulted in a stopover that lasted 22 ± 7 min compared to 85% at the other landfill lasting 63 ± 15 min. We concluded that the integrated program using falconry, which we consider more socially acceptable than selective culling, was effective in reducing the number of gulls at the landfill. PMID:26479231

  20. Modelling terrestrial and marine foraging habitats in breeding Audouin's gulls Larus audouinii: timing matters.

    PubMed

    Bécares, Juan; García-Tarrasón, Manuel; Villero, Dani; Bateman, Santiago; Jover, Lluís; García-Matarranz, Víctor; Sanpera, Carolina; Arcos, José Manuel

    2015-01-01

    Although the breeding ecology of Audouin's gull has been widely studied, its spatial distribution patterns have received little attention. We assessed the foraging movements of 36 GPS-tracked adult Audouin's gulls breeding at the Ebro Delta (NW Mediterranean), coinciding with the incubation period (May 2011). This also coincided with a trawling moratorium northwards from the colony. We modelled the distribution of the gulls by combining these tracking data with environmental variables (including fishing activities from Vessel Monitoring System, VMS), using Maxent. The modelling range included both marine and terrestrial areas. Models were produced separately for every 2h time interval across the day, and for 2 fishing activity scenarios (workdays vs. weekends), allowing to assess the spatio-temporal distribution patterns of the gulls and the degree of association with fisheries. During workdays, gull distribution at sea fully matched with fishing activities, both trawling (daylight) and purse-seining (nightime). Gulls tended to avoid the area under trawling moratorium, confirming the high influence of fisheries on the distribution patterns of this species. On weekends, gulls made lesser use of the sea and tended to increase the use of rice fields. Overall, Audouin's gull activity was more intense during dailight hours, although birds also showed nocturnal activity, on both workdays and weekends. Nocturnal patterns at sea were more disperse during the latter, probably because these gulls are able to capture small pelagic fish at night in natural conditions, but tend to congregate around purse-seiners (which would enhance their foraging efficiency) in workdays. These results provide important insight for the management of this species. This is of particular relevance under the current scenario of European fisheries policies, since new regulations are aimed at eliminating discards, and this would likely influence Audouin's gull populations. PMID:25875597

  1. Modelling Terrestrial and Marine Foraging Habitats in Breeding Audouin's Gulls Larus audouinii: Timing Matters

    PubMed Central

    Bécares, Juan; García-Tarrasón, Manuel; Villero, Dani; Bateman, Santiago; Jover, Lluís; García-Matarranz, Víctor; Sanpera, Carolina; Arcos, José Manuel

    2015-01-01

    Although the breeding ecology of Audouin’s gull has been widely studied, its spatial distribution patterns have received little attention. We assessed the foraging movements of 36 GPS-tracked adult Audouin’s gulls breeding at the Ebro Delta (NW Mediterranean), coinciding with the incubation period (May 2011). This also coincided with a trawling moratorium northwards from the colony. We modelled the distribution of the gulls by combining these tracking data with environmental variables (including fishing activities from Vessel Monitoring System, VMS), using Maxent. The modelling range included both marine and terrestrial areas. Models were produced separately for every 2h time interval across the day, and for 2 fishing activity scenarios (workdays vs. weekends), allowing to assess the spatio-temporal distribution patterns of the gulls and the degree of association with fisheries. During workdays, gull distribution at sea fully matched with fishing activities, both trawling (daylight) and purse-seining (nightime). Gulls tended to avoid the area under trawling moratorium, confirming the high influence of fisheries on the distribution patterns of this species. On weekends, gulls made lesser use of the sea and tended to increase the use of rice fields. Overall, Audouin’s gull activity was more intense during dailight hours, although birds also showed nocturnal activity, on both workdays and weekends. Nocturnal patterns at sea were more disperse during the latter, probably because these gulls are able to capture small pelagic fish at night in natural conditions, but tend to congregate around purse-seiners (which would enhance their foraging efficiency) in workdays. These results provide important insight for the management of this species. This is of particular relevance under the current scenario of European fisheries policies, since new regulations are aimed at eliminating discards, and this would likely influence Audouin’s gull populations. PMID:25875597

  2. A century of ecosystem change: human and seabird impacts on plant species extirpation and invasion on islands

    PubMed Central

    Bennett, Joseph R.; Blight, Louise K.; Giesen, Marissa; Janssen, Michael H.; Schaminée, Joop J.H.J.; Arcese, Peter

    2016-01-01

    We used 116 years of floral and faunal records from Mandarte Island, British Columbia, Canada, to estimate the indirect effects of humans on plant communities via their effects on the population size of a surface-nesting, colonial seabird, the Glaucous-winged gull (Larus glaucescens). Comparing current to historical records revealed 18 extirpations of native plant species (32% of species historically present), 31 exotic species introductions, and one case of exotic introduction followed by extirpation. Contemporary surveys indicated that native species cover declined dramatically from 1986 to 2006, coincident with the extirpation of ‘old-growth’ conifers. Because vegetation change co-occurred with an increasing gull population locally and regionally, we tested several predictions from the hypothesis that the presence and activities of seabirds help to explain those changes. Specifically, we predicted that on Mandarte and nearby islands with gull colonies, we should observe higher nutrient loading and exotic plant species richness and cover than on nearby islands without gull colonies, as a consequence of competitive dominance in species adapted to high soil nitrogen and trampling. As predicted, we found that native plant species cover and richness were lower, and exotic species cover and richness higher, on islands with versus without gull colonies. In addition, we found that soil carbon and nitrogen on islands with nesting gulls were positively related to soil depth and exotic species richness and cover across plots and islands. Our results support earlier suggestions that nesting seabirds can drive rapid change in insular plant communities by increasing nutrients and disturbing vegetation, and that human activities that affect seabird abundance may therefore indirectly affect plant community composition on islands with seabird colonies. PMID:27547531

  3. A century of ecosystem change: human and seabird impacts on plant species extirpation and invasion on islands.

    PubMed

    Lameris, Thomas K; Bennett, Joseph R; Blight, Louise K; Giesen, Marissa; Janssen, Michael H; Schaminée, Joop J H J; Arcese, Peter

    2016-01-01

    We used 116 years of floral and faunal records from Mandarte Island, British Columbia, Canada, to estimate the indirect effects of humans on plant communities via their effects on the population size of a surface-nesting, colonial seabird, the Glaucous-winged gull (Larus glaucescens). Comparing current to historical records revealed 18 extirpations of native plant species (32% of species historically present), 31 exotic species introductions, and one case of exotic introduction followed by extirpation. Contemporary surveys indicated that native species cover declined dramatically from 1986 to 2006, coincident with the extirpation of 'old-growth' conifers. Because vegetation change co-occurred with an increasing gull population locally and regionally, we tested several predictions from the hypothesis that the presence and activities of seabirds help to explain those changes. Specifically, we predicted that on Mandarte and nearby islands with gull colonies, we should observe higher nutrient loading and exotic plant species richness and cover than on nearby islands without gull colonies, as a consequence of competitive dominance in species adapted to high soil nitrogen and trampling. As predicted, we found that native plant species cover and richness were lower, and exotic species cover and richness higher, on islands with versus without gull colonies. In addition, we found that soil carbon and nitrogen on islands with nesting gulls were positively related to soil depth and exotic species richness and cover across plots and islands. Our results support earlier suggestions that nesting seabirds can drive rapid change in insular plant communities by increasing nutrients and disturbing vegetation, and that human activities that affect seabird abundance may therefore indirectly affect plant community composition on islands with seabird colonies. PMID:27547531

  4. Sedimentary characteristics of carbonate intra-platform shoals and their formation in Ordovician Tarim Basin, West China

    NASA Astrophysics Data System (ADS)

    Meng, M.

    2015-12-01

    The widely distributed carbonate intra-platform shoals has become a new important exploration target within the Tarim Basin, where reservoirs of Yubei oil-field (discovered in 2011) and the Shunnan oil-field (discovered in 2013) occur. Better understanding of the sedimentary characteristics and formation of intra-platform shoals is significant for predicting the distribution of Ordovician shoal reservoirs. The sedimentary characteristics, distribution patterns and formation mechanisms of carbonate intra-platform shoals in Ordovician Tarim Basin were studied based on outcrop analogue, core data, thin section observation, seismic, and well log data. Those shoals include oolitic shoal, intraclast shoal and bioclastic shoal. The intra-platform shoal consists of three sedimentary units: shoal base, shoal core and shoal cover, which are adjacent to intershoal sea faces. Laterally, the intra-platform shoals occurred as a more continuous sheet-like body.The intra-platform shoals deposited mainly in the lowstand systems tract and late stage of highstand systems tract. Several factors were probably responsible for the occurrence of intra-platform shoals, including: (i) a relatively shallow-water condition with a strong hydrodynamic environment, (ii) high-frequency oscillations of the sea level, and (iii) Subtle paleo-highs and relatively weak structural activities, which are important for the spatial distribution of reservoir facies.

  5. The distribution and conservation status of the Gull-billed Tern (Gelochelidon nilotica) in North America

    USGS Publications Warehouse

    Molina, K.C.; Erwin, R.M.

    2006-01-01

    The Gull-billed Tern (Gelochelidon nilotica) has until recently received little conservation and management attention within North America despite a relatively low overall population size and significant declines in parts of the breeding range. This lack of attention may stem in part from the wide distribution of the species, encompassing parts of six continents, and from its tendency to nest in relatively small, scattered and often ephemeral colonies. Populations of North American subspecies are alarmingly small. The current population of the eastern subspecies aranea in the U.S. is unlikely to exceed 3,600 pairs, with over 60% of these birds occurring in Texas. The Texas population has remained generally stable, but declines of populations in Maryland (where probably extirpated), Virginia, North Carolina, Florida, and possibly Georgia give cause for concern for this subspecies. For the western subspecies vanrossemi, as few as 250 pairs nest at only two locations in the U.S., both in California. When populations in western Mexico are considered, the entire vanrossemi population numbers only 600-800 pairs. Currently the Gull-billed Tern is listed as ?endangered? or ?threatened? in four states, and is considered to be of management concern in five others. The breeding range of the species has contracted and shifted slightly from its known historic range in the middle Atlantic states, but otherwise occupies its historic range in the United States and has expanded slightly to coastal southern California. Some range contraction in Mexico (e.g., in Sonora) may have occurred. In eastern Mexico, historical information is almost non-existent and knowledge of current distribution and abundance is incomplete. Main threats to populations in North America include loss of natural nesting islands through beach erosion or perturbations to estuarine functions, development or modification of upland habitats near breeding areas that may be important for foraging, and disturbances to

  6. Letter Report: Contaminant Boundary at the Shoal Underground Nuclear Test

    SciTech Connect

    Greg Pohll; Karl Pohlmann

    2004-08-06

    As part of the corrective action strategy reached between the U.S. Department of Energy and the State of Nevada, the extent and potential impact of radionuclide contamination of groundwater at underground nuclear test locations must be addressed. This report provides the contaminant boundary for the Project Shoal Site, based on the groundwater flow and transport model for the site, by Pohlmann et al.

  7. Microsatellites identify depredated waterfowl remains from glaucous gull stomachs

    USGS Publications Warehouse

    Scribner, K.T.; Bowman, T.D.

    1998-01-01

    Prey remains can provide valuable sources of information regarding causes of predation and the species composition of a predator's diet. Unfortunately, the highly degraded state of many prey samples from gastrointestinal tracts often precludes unambiguous identification. We describe a procedure by which PCR amplification of taxonomically informative microsatellite loci were used to identify species of waterfowl predated by glaucous gulls (Larus hyperboreus). We found that one microsatellite locus unambiguously distinguished between species of the subfamily Anserinae (whistling ducks, geese and swans) and those of the subfamily Anatidae (all other ducks). An additional locus distinguished the remains of all geese and swan species known to nest on the Yukon-Kuskokwim delta in western Alaska. The study focused on two waterfowl species which have experienced precipitous declines in population numbers: emperor geese (Chen canagica) and spectacled eiders (Somateria fischeri). No evidence of predation on spectacled eiders was observed. Twenty-six percent of all glaucous gull stomachs examined contained the remains of juvenile emperor geese.

  8. Flow separation and resuspension beneath shoaling nonlinear internal waves

    NASA Astrophysics Data System (ADS)

    Boegman, Leon; Ivey, Gregory N.

    2009-02-01

    Laboratory observations are presented showing the structure and dynamics of the turbulent bottom boundary layer beneath nonlinear internal waves (NLIWs) of depression shoaling upon sloping topography. The adverse pressure gradient beneath the shoaling waves causes the rear face to steepen, flow separation to occur, and wave-induced near-bottom vortices to suspend bed material. The resuspension is directly attributed to the near-bed viscous stress and to near-bed patches of elevated positive Reynolds stress generated by the vortical structures. These results are consistent with published field observations of resuspension events beneath shoaling NLIWs. Elevated near-bed viscous stresses are found throughout the domain at locations that are not correlated to the resuspension events. Near-bed viscous stress is thus required for incipient sediment motion but is not necessarily a precursor for resuspension. Resuspension is dependent on the vertical velocity field associated with positive Reynolds stress and is also found to occur where the mean (wave-averaged) vertical velocity is directed away from the bed. The results are interpreted by analogy to the eddy-stress and turbulent bursting resuspension models developed for turbulent channel flows.

  9. Integrating Ecology and Geomorphology in Etowah River Shoal Restoration

    NASA Astrophysics Data System (ADS)

    Duncan, W. W.; Meyer, J. L.; Leigh, D.; Goodloe, R.

    2005-05-01

    Designs of stream restoration projects are typically based primarily on geomorphic data. However, these data may not be comprehensive enough to design ecologically successful restoration projects. In summer 2004 Georgia Ecological Services (U.S. Fish and Wildlife Service) surveyed nearly 80 km of the Etowah River, GA. The goal of this survey was to identify sediment sources and potential restoration techniques that would benefit imperiled, shoal-inhabiting fishes in the Etowah River. An essential and unique part of this survey was to collect both ecological and geomorphic data to build a more holistic understanding of how and why shoal habitats vary. One ecological measure included was the density and length of river weed Podostemum ceratophyllum, a submerged aquatic macrophyte. Other studies have shown that the imperiled "Coosa" madtom (Noturus sp. cf. N. munitus) and freckled darter (Percina lenticula) occur more frequently in the presence of Podostemum. Results indicate that the density and length of Podostemum increases with shoal width and particle size, highlighting the importance of geomorphology in its growth. Restoration activities that focus on these habitat characteristics will facilitate Podostemum growth and will probably aid in the recovery of the "Coosa" madtom and freckled darter in the Etowah River.

  10. Pleistocene barrier bar seaward of ooid shoal complex near Miami, Florida

    USGS Publications Warehouse

    Halley, Robert B.; Shinn, Eugene A.; Hudson, J. Harold; Lidz, Barbara H.

    1977-01-01

    An ooid sand barrier bar of Pleistocene age was deposited along the seaward side of an ooid shoal complex southwest of Miami, Florida. The bar is 35 km long, about 0.8 km wide, elongate parallel with the trend of the ooid shoal complex and perpendicular to channels between individual shoals. A depression 1.6 km wide, interpreted as a back-barrier channel, isolates the bar from the ooid shoals. During sea-level fall and subaerial exposure of the bar, the ooid sand was cemented in place, preventing migration of the barrier. No Holocene analogue of this sand body is recognized, perhaps because of the relative youthfulness of Holocene ooid shoals. This Pleistocene ooid shoal complex, with its reservoir-size barrier bar, may serve as a refined model for exploration in ancient ooid sand belts.

  11. Safety in numbers? Shoaling behaviour of the Amazonian red-bellied piranha.

    PubMed

    Queiroz, Helder; Magurran, Anne E

    2005-06-22

    Red-bellied piranha (Pygocentrus nattereri) shoals have a fearsome reputation. However, the variety and abundance of piranha predators in the flooded forests of the Amazon in which they live indicate that an important reason for shoal formation may be predator defence. Experiments using wild-caught piranhas supported the hypothesis that individual perception of risk, as revealed by elevated ventilatory frequency (opercular rate), is greater in small shoals. Moreover, exposure to a simulated predator attack by a model cormorant demonstrated that resting opercular rates are regained more quickly by piranhas in shoals of eight than they are in shoals of two. Together, these results show that shoaling has a cover-seeking function in this species. PMID:17148153

  12. Finding of pentastomes of genus Reighardia (Pentastomida) in the Belcher's gull (Larus belcheri).

    PubMed

    Naupay, Asucena I; Cribillero, Nelly G; Lopez-Urbina, Maria T; Gonzalez, Armando E; Gomez-Puerta, Luis A

    2016-06-01

    This report describes the finding of Reighardia sp. (Pentastomida) infecting the air sac of two Belcher's gulls (Larus belcheri) found dead on the beaches of Pucusana, a district in southern Lima, Peru. Three pentastomes were collected from two Belcher's gulls. Then, they were morphologically and molecular analyzed. Molecular characterization of the parasite was achieved by amplifying a fragment of the small subunit ribosomal RNA gene (SSU rRNA). Based on both morphological and molecular data the pentastomes were identified as pentastomes of the genus Reighardia. This is the first report showing that the Belcher's gull is a new natural definitive host for this pentastome. PMID:26892103

  13. Insects, vegetation, and the control of laughing gulls (Larus atricilla) at Kennedy International Airport, New York

    USGS Publications Warehouse

    Buckley, P.A.; McCarthy, M.

    1994-01-01

    1. In response to a purported 'bird-strike problem' at J.F. Kennedy International Airport in New York City, we examined short (5 cm) and long (45 cm) grass heights as gull deterrents, in a randomized-block experiment. 2. Vegetative cover, numbers of adult insects and of larval beetles (suspected on-airport food of the gulls) were sampled in the six-block, 36-plot study area, as well as gut contents of adult and downy young gulls in the immediately adjacent colony in the Jamaica Bay Wildlife Refuge. 3. We found that (i) Oriental beetle larvae were the most numerous and concentrated in one experimental block; (ii) beetle larvae numbers were uncorrelated with grass height; (iii) adult beetles were also uncorrelated with grass height; (iv) laughing gulls were distributed across blocks irrespective of percentage cover; (v) within blocks, laughing gulls were selecting short grass and avoiding long grass plots; (vi) laughing gull numbers were positively associated with numbers of Oriental beetle larvae; (vii) adult laughing gulls on the airport were eating lower-nutrition food of terrestrial origin (74-83% adult beetles, mostly Oriental plus green June and ground beetles); (viii) on the other hand, gull chicks in the adjacent breeding colony were being fed more easily digested, higher-protein food of marine origin (86-88% fishes, crustacea and molluscs); (ix) laughing gulls on the airport were taking their adult beetles only in short-grass plots, ignoring large numbers in adjacent long grass; (x) during the summer, on-airport gulls shifted from performing largely maintenance activities on pavement to feeding actively for beetles on newly mown short grass, the change coinciding with adult beetle emergence; (xi) standing water on the airport attracted significantly more gulls than dry areas all summer long. 4. We recommend a series of ecologically compatible, but aggressive habitat management actions for controlling laughing gulls on Kennedy Airport by rendering the airport

  14. Cyclic behavior of sandy shoals on the ebb-tidal deltas of the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Ridderinkhof, W.; Hoekstra, P.; van der Vegt, M.; de Swart, H. E.

    2016-03-01

    Ebb-tidal deltas are bulges of sand that are located seaward of tidal inlets. Many of these deltas feature shoals that cyclically form and migrate towards the coast. The average period between successive shoals that attach to the coast varies among different inlets. In this study, a quantitative assessment of the cyclic behavior of shoals on the ebb-tidal deltas of the Wadden Sea is presented. Analysis of bathymetric data and Landsat satellite images revealed that at the majority of inlets along the Wadden Sea migrating shoals occur. The average period between succeeding shoals correlates to the tidal prism and has values ranging between 4 and 130 years. A larger tidal prism favors larger periods between successive shoal attachments. However, such a relationship was not found for wide inlets with multiple channels. There is a positive relationship between the frequency with which the shoals attach to the coast and their migration velocity, and a negative relationship between the migration velocity of the shoal and the tidal prism. Finally, the data were too sparse to assess whether the longshore sediment transport has a significant effect on the period between successive shoals that attach to the coasts downdrift of the observed tidal inlets.

  15. Modeling colony site dynamics: a case study of gull-billed terns (Sterna nilotica) in coastal Virginia

    USGS Publications Warehouse

    Erwin, R.M.; Nichols, J.D.; Eyler, T.B.; Stotts, D.B.; Truitt, B.R.

    1998-01-01

    We developed a Markov process model for colony site dynamics of Gull-billed Terns (Sterna nilotica) in coastal Virginia. We used the model and data on colony site occupation from 1993 to 1996 to estimate model parameters. Each year, we monitored the breeding numbers of Gull-billed Terns and their frequent colony associates, Common Terns (Sterna hirundo) and Black Skimmers (Rynchops niger) at colony sites along about 80 km of the barrier island region of Virginia. We also monitored flooding events and renesting. We developed the model for colony survival, extinction, and recolonization at potential colony sites over the four-year period. We then used data on annual site occupation by Gull-billed Terns to estimate model parameters and test between different structures reflecting competing hypotheses. Results revealed a dynamic system, but provided no evidence that the dynamics were Markovian , i.e. the probability of occupancy of a site in one year was not influenced by whether it had been occupied the previous year. Nor did the colony-level reproductive success the previous season seem to affect the probability of site occupancy. Site survival and recolonization rates were similar, and the overall annual probability of a site being occupied over the course of the four-year period was estimated to be 0.59 Of the total of 25 sites that were used during the four-year period, 16 were used in only one or two years while only three were used all four years.. Flooding and renesting were frequent in both habitat types in all years. The frequent flooding of nests on shellpiles argues for more effective management; augmentation with shell and sand to increase elevations as little as 20 cm could have reduced flooding at a number of sites. The low colony-site fidelity we demonstrate suggests that an effective management approach is to provide a large number of alternative sand and/or shellpile sites that the terns may use. Sites not used one year may still be used in subsequent

  16. Infectious bursal disease virus antibodies in eider ducks and Herring Gulls

    USGS Publications Warehouse

    Hollmen, T.; Franson, J.C.; Docherty, D.E.; Kilpi, Mikael; Hario, Martti; Creekmore, L.H.; Petersen, M.R.

    2000-01-01

    We measured antibodies to infectious bursal disease virus (IBDV) in blood of nesting Common Eider (Somateria mollissima) females and immature Herring Gulls (Larus argentatus) in the Baltic Sea, and in blood of Spectacled Eider (Somateria fischeri) females nesting in a remote area of western Alaska. Positive (??? 1:16) IBDV titers occurred in 75% of the eiders and 45% of the Herring Gull chicks. In eiders, the prevalence of positive titers differed among locations. We found no evidence that IBDV exposure impaired the immune function of Herring Gull chicks, based on their response to inoculation of sheep red blood cells. We suggest that eider ducks and Herring Gulls have been exposed to IBDV, even in locations where contact with poultry is unlikely. The presence of this virus in wild bird populations is of concern because it causes mortality of up to 30% in susceptible poultry.

  17. Observations of a live Glaucous-winged Gull chick in an active Bald Eagle nest

    USGS Publications Warehouse

    Anthony, R.G.; Faris, J.T.

    2003-01-01

    We report an apparent nonlethal predation attempt on and subsequent adoption of a Glaucous-winged Gull (Larus glaucescens) chick by a pair of Bald Eagles (Haliaeetus leucocephalus) in the Aleutian Archipelago, Alaska. To the best of our knowledge, this is the first report of a live Glaucous-winged Gull chick in a Bald Eagle nest. We describe our observations of this occurrence and offer explanations on how it may have occurred.

  18. Geographic, temporal, and age-specific variation in diets of Glaucous Gulls in western Alaska

    USGS Publications Warehouse

    Schmutz, J.A.; Hobson, K.A.

    1998-01-01

    We collected boluses and food remains of adult Glaucous Gulls (Larus hyperboreus) at or near nests and chicks, and digestive tracts from adults at three sites on the Yukon-Kuskokwim Delta, Alaska that differed in proximity to marine and terrestrial foods. We observed both geographic and temporal variation in diet; gulls consumed proportionately more terrestrial prey after peak hatch in late June, and gulls near the coast consumed proportionately more marine prey than gulls at two inland areas. Goslings occurred in > 60% of all samples from these inland areas. We compared these data to those from a previous study in western Alaska and found no marked differences. Evidence for similar patterns of geographic and temporal variation in diet was found using measurements of stable-carbon and nitrogen isotopes in gull and prey tissues. Stable isotope analysis further revealed that adult gulls consumed proportionately more marine prey (saffron cod, Eleginus gracilis) than they fed to their young. Using isotopic models, we estimated that 7-22% and 10-23% of the diet of adult and juvenile Glaucous Gulls, respectively, was comprised of terrestrial species. In addition to significant age-related variation, dietary estimates varied among geographic areas and between pre- and post-hatch periods. Overall, our isotopic estimates of the contribution of terrestrial prey to the diet of Glaucous Gulls was less than what may be inferred from conventional methods of diet analysis. Our study emphasizes the benefit of combining stable-isotope and conventional analyses to infer temporal and geographic changes in diet of wild birds and other organisms.

  19. Circulation of a Meaban-Like Virus in Yellow-Legged Gulls and Seabird Ticks in the Western Mediterranean Basin

    PubMed Central

    Cerdà-Cuéllar, Marta; Lecollinet, Sylvie; Pearce-Duvet, Jessica; Busquets, Núria; García-Bocanegra, Ignacio; Pagès, Nonito; Vittecoq, Marion; Hammouda, Abdessalem; Samraoui, Boudjéma; Garnier, Romain; Ramos, Raül; Selmi, Slaheddine; González-Solís, Jacob; Jourdain, Elsa; Boulinier, Thierry

    2014-01-01

    In recent years, a number of zoonotic flaviviruses have emerged worldwide, and wild birds serve as their major reservoirs. Epidemiological surveys of bird populations at various geographical scales can clarify key aspects of the eco-epidemiology of these viruses. In this study, we aimed at exploring the presence of flaviviruses in the western Mediterranean by sampling breeding populations of the yellow-legged gull (Larus michahellis), a widely distributed, anthropophilic, and abundant seabird species. For 3 years, we sampled eggs from 19 breeding colonies in Spain, France, Algeria, and Tunisia. First, ELISAs were used to determine if the eggs contained antibodies against flaviviruses. Second, neutralization assays were used to identify the specific flaviviruses present. Finally, for colonies in which ELISA-positive eggs had been found, chick serum samples and potential vectors, culicid mosquitoes and soft ticks (Ornithodoros maritimus), were collected and analyzed using serology and PCR, respectively. The prevalence of flavivirus-specific antibodies in eggs was highly spatially heterogeneous. In northeastern Spain, on the Medes Islands and in the nearby village of L'Escala, 56% of eggs had antibodies against the flavivirus envelope protein, but were negative for neutralizing antibodies against three common flaviviruses: West Nile, Usutu, and tick-borne encephalitis viruses. Furthermore, little evidence of past flavivirus exposure was obtained for the other colonies. A subset of the Ornithodoros ticks from Medes screened for flaviviral RNA tested positive for a virus whose NS5 gene was 95% similar to that of Meaban virus, a flavivirus previously isolated from ticks of Larus argentatus in western France. All ELISA-positive samples subsequently tested positive for Meaban virus neutralizing antibodies. This study shows that gulls in the western Mediterranean Basin are exposed to a tick-borne Meaban-like virus, which underscores the need of exploring the spatial and

  20. Weathered oil: effect on hatchability of heron and gull eggs

    SciTech Connect

    Macko, S.A.; King, S.M.

    1980-08-01

    Contact with weathered oil seems more likely for waterbirds than contact with fresh oil; however, the effects of weathered oil on embryo survival have only partially been explored. Results of one study showed that 20 ..mu..L of 4 week-old crude oil applied to the eggshell surface caused a significant decrease in embryo survival of mallard (Anas platyrhynchos) eggs. In that study, oil was weathered under laboratory conditions using fresh water. To our knowledge, there have been no tests to determine the effects on egg hatchability of oil naturally weathered in marine habitats. The present study assesses the effects of external applications of naturally weathered crude oil on embryo survival of Louisiana heron (Hydranassa tricolor) and laughing gull (Larus atricilla) eggs.

  1. Spatio-Temporal Structure of Hooded Gull Flocks

    PubMed Central

    Yomosa, Makoto; Mizuguchi, Tsuyoshi; Hayakawa, Yoshinori

    2013-01-01

    We analyzed the spatio-temporal structure of hooded gull flocks with a portable stereo camera system. The 3-dimensional positions of individuals were reconstructed from pairs of videos. The motions of each individual were analyzed, and both gliding and flapping motions were quantified based on the velocity time series. We analyzed the distributions of the nearest neighbor’s position in terms of coordinates based on each individual’s motion. The obtained results were consistent with the aerodynamic interaction between individuals. We characterized the leader-follower relationship between individuals by a delay time to mimic the direction of a motion. A relation between the delay time and a relative position was analyzed quantitatively, which suggested the basic properties of the formation flight that maintains order in the flock. PMID:24339960

  2. Diets of nestling gull-billed terns in coastal Virginia

    USGS Publications Warehouse

    Erwin, R.M.; Eyler, T.B.; Hatfield, J.S.; McGary, S.

    1998-01-01

    We studied the diets of nestling Gull-billed Terns (Sterna nilotica) at colonies in coastal Virginia during the breeding seasons of 1995 and 1996 as part of a long-term study of the species. No previous quantitative assessments had been made of diets of this species anywhere along the Atlantic Coast, and only a few observations had been reported from other coastal areas in the southern United States. During 80 h of observations over the two seasons, 757 feeding observations were made, primarily at two colony sites. We examined how prey type (fish, marine invertebrates, terrestrial prey) and size were influenced by year, tide cycle, season (early and late) and age of the young (small chicks 7 d). We did not find significant year differences, but all other factors revealed statistically significant results. Older (>7 d) chicks were fed relatively more terrestrial and marine invertebrate prey than were younger chicks. In June (early season), fewer fish and terrestrial prey were fed to chicks than later (July-August). Most prey were less than one bill length in size, with the majority of the smallest prey being marine invertebrates. Tide cycle influenced prey delivered with terrestrial prey becoming relatively more important during high and ebb periods than during low and flood tides when aquatic prey dominated. The major marine invertebrate prey taken was the fiddler crab (Uca spp.). Terrestrial prey consisted mostly of large odonates and orthopterans. Unlike earlier reports from Europe, we found no regurgitated food pellets in any of the colonies in either year. This study confirms that the Gull-billed Tern is an extremely opportunistic feeder and has adapted to a variety of habitats, helping to explain its cosmopolitan distribution.

  3. Diets of nestling Gull-billed Terns in coastal Virginia

    USGS Publications Warehouse

    Erwin, R.M.; Eyler, T.B.; Hatfield, J.S.; McGary, S.

    1998-01-01

    We studied the diets of nestling Gull-billed Terns (Sterna nilotica) at colonies in coastal Virginia during the breeding seasons of 1995 and 1996 as part of a long-term study of the species. No previous quantitative assessments had been made of diets of this species anywhere along the Atlantic Coast, and only a few observations had been reported from other coastal areas in the southern United States. During 80 h of observations over the two seasons, 757 feeding observations were made, primarily at two colony sites. We examined how prey type (fish, marine invertebrates, terrestrial prey) and size were influenced by year, tide cycle, season (early and late) and age of the young (small chicks 7 d). We did not find significant year differences, but all other factors revealed statistically significant results. Older (>7 d) chicks were fed relatively more terrestrial and marine invertebrate prey than were younger chicks. In June (early season), fewer fish and terrestrial prey were fed to chicks than later (July-August). Most prey were less than one bill length in size, with the majority of the smallest prey being marine invertebrates. Tide cycle influenced prey delivered with terrestrial prey becoming relatively more important during high and ebb periods than during low and flood tides when aquatic prey dominated. The major marine invertebrate prey taken was the fiddler crab (Uca spp.). Terrestrial prey consisted mostly of large odonates and orthopterans. Unlike earlier reports from Europe, we found no regurgitated food pellets in any of the colonies in either year. This study confirms that the Gull-billed Tern is an extremely opportunistic feeder and has adapted to a variety of habitats, helping to explain its cosmopolitan distribution.

  4. Identification and characterization of a novel adenovirus in the cloacal bursa of gulls

    SciTech Connect

    Bodewes, R.; Bildt, M.W.G. van de; Schapendonk, C.M.E.; Leeuwen, M. van; Boheemen, S. van; Jong, A.A.W. de; Osterhaus, A.D.M.E.; Smits, S.L.; Kuiken, T.

    2013-05-25

    Several viruses of the family of Adenoviridae are associated with disease in birds. Here we report the detection of a novel adenovirus in the cloacal bursa of herring gulls (Larus argentatus) and lesser black-backed gulls (Larus fuscus) that were found dead in the Netherlands in 2001. Histopathological analysis of the cloacal bursa revealed cytomegaly and karyomegaly with basophilic intranuclear inclusions typical for adenovirus infection. The presence of an adenovirus was confirmed by electron microscopy. By random PCR in combination with deep sequencing, sequences were detected that had the best hit with known adenoviruses. Phylogenetic analysis of complete coding sequences of the hexon, penton and polymerase genes indicates that this novel virus, tentatively named Gull adenovirus, belongs to the genus Aviadenovirus. The present study demonstrates that birds of the Laridae family are infected by family-specific adenoviruses that differ from known adenoviruses in other bird species. - Highlights: ► Lesions typical for adenovirus infection detected in cloacal bursa of dead gulls. ► Confirmation of adenovirus infection by electron microscopy and deep sequencing. ► Sequence analysis indicates that it is a novel adenovirus in the genus Aviadenovirus. ► The novel (Gull) adenovirus was detected in multiple organs of two species of gulls.

  5. Quantifying fall migration of Ross's gulls (Rhodostethia rosea) past Point Barrow, Alaska

    USGS Publications Warehouse

    Uher-Koch, Brian D.; Davis, Shanti E.; Maftei, Mark; Gesmundo, Callie; Suydam, R.S.; Mallory, Mark L.

    2014-01-01

    The Ross's gull (Rhodostethia rosea) is a poorly known seabird of the circumpolar Arctic. The only place in the world where Ross's gulls are known to congregate is in the near-shore waters around Point Barrow, Alaska where they undertake an annual passage in late fall. Ross's gulls seen at Point Barrow are presumed to originate from nesting colonies in Siberia, but neither their origin nor their destination has been confirmed. Current estimates of the global population of Ross's gulls are based largely on expert opinion, and the only reliable population estimate is derived from extrapolations from previous counts conducted at Point Barrow, but these data are now over 25 years old. In order to update and clarify the status of this species in Alaska, our study quantified the timing, number, and flight direction of Ross's gulls passing Point Barrow in 2011. We recorded up to two-thirds of the estimated global population of Ross's gulls (≥ 27,000 individuals) over 39 days with numbers peaking on 16 October when we observed over 7,000 birds during a three-hour period.

  6. The Sound of Danger: Threat Sensitivity to Predator Vocalizations, Alarm Calls, and Novelty in Gulls

    PubMed Central

    MacLean, Sarah A.; Bonter, David N.

    2013-01-01

    The threat sensitivity hypothesis predicts that organisms will evaluate the relative danger of and respond differentially to varying degrees of predation threat. Doing so allows potential prey to balance the costs and benefits of anti-predator behaviors. Threat sensitivity has undergone limited testing in the auditory modality, and the relative threat level of auditory cues from different sources is difficult to infer across populations when variables such as background risk and experience are not properly controlled. We experimentally exposed a single population of two sympatric gull species to auditory stimuli representing a range of potential threats in order to compare the relative threat of heterospecific alarm calls, conspecific alarms calls, predator vocalizations, and novel auditory cues. Gulls were able to discriminate among a diverse set of threat indicators and respond in a graded manner commensurate with the level of threat. Vocalizations of two potential predators, the human voice and bald eagle call, differed in their threat level compared to each other and to alarm calls. Conspecific alarm calls were more threatening than heterospecfic alarm calls to the larger great black-backed gull, but the smaller herring gull weighed both equally. A novel cue elicited a response intermediate between known threats and a known non-threat in herring gulls, but not great black-backed gulls. Our results show that the relative threat level of auditory cues from different sources is highly species-dependent, and that caution should be exercised when comparing graded and threshold threat sensitive responses. PMID:24324780

  7. The sound of danger: threat sensitivity to predator vocalizations, alarm calls, and novelty in gulls.

    PubMed

    MacLean, Sarah A; Bonter, David N

    2013-01-01

    The threat sensitivity hypothesis predicts that organisms will evaluate the relative danger of and respond differentially to varying degrees of predation threat. Doing so allows potential prey to balance the costs and benefits of anti-predator behaviors. Threat sensitivity has undergone limited testing in the auditory modality, and the relative threat level of auditory cues from different sources is difficult to infer across populations when variables such as background risk and experience are not properly controlled. We experimentally exposed a single population of two sympatric gull species to auditory stimuli representing a range of potential threats in order to compare the relative threat of heterospecific alarm calls, conspecific alarms calls, predator vocalizations, and novel auditory cues. Gulls were able to discriminate among a diverse set of threat indicators and respond in a graded manner commensurate with the level of threat. Vocalizations of two potential predators, the human voice and bald eagle call, differed in their threat level compared to each other and to alarm calls. Conspecific alarm calls were more threatening than heterospecfic alarm calls to the larger great black-backed gull, but the smaller herring gull weighed both equally. A novel cue elicited a response intermediate between known threats and a known non-threat in herring gulls, but not great black-backed gulls. Our results show that the relative threat level of auditory cues from different sources is highly species-dependent, and that caution should be exercised when comparing graded and threshold threat sensitive responses. PMID:24324780

  8. Gull contributions of phosphorus and nitrogen to a Cape Cod kettle pond

    USGS Publications Warehouse

    Portnoy, J.W.; Soukup, M.A.

    1990-01-01

    Nutrient excretion rates and the annual contribution of P from the feces of the gulls Larus argentatus and L. marinus (and of N from L. argentatus) to the nutrient budget of Gull Pond (Wellfleet), a soft water seepage lake, have been estimated. Intensive year-round gull counts by species were combined with determinations of defecation rate and the nutrient content of feces to quantitatively assess the P loading rates associated with regular gull use of this coastal pond on a seasonal and annual basis. Total P loading from gulls was estimated to be 52 kg yr?1, with 17 kg from L. argentatus and 35 kg from L. marinus, resulting from about 5.0 ? 106 h yr?1 and 1.7 ? 106 h yr?1 of pond use. This compares with P loading estimates of 67 kg yr?1 from upgradient septic systems, 2 kg yr?1 from precipitation and 3 kg yr?1 from unpolluted ground water. Fifty-six percent of annual gull P loading was associated with migratory activity in late fall. Estimated annual N loading by L. argentatus was 14 kg TKN, 206 g NO3-N, and 1.85 g g NH3-N.

  9. The Efficiency of an Integrated Program Using Falconry to Deter Gulls from Landfills

    PubMed Central

    Thiériot, Ericka; Patenaude-Monette, Martin; Molina, Pierre; Giroux, Jean-François

    2015-01-01

    Simple Summary We evaluated the long-term effect of an intensive integrated program based on falconry to deter gulls, mostly ring-billed gulls (Larus delawarensis), from a landfill. Gulls were counted at different periods each day, and the annual sum of the maximum count at any observation period each day declined from over 1.1 million to only 20,300 during the 20 years of the study. This could not be explained by a decline in the local breeding population that remained relatively large throughout this period as determined in a concomitant study. The effectiveness of the falconry program was also confirmed by tracking individual birds fitted with GPS data loggers. The tagged gulls stopped less often and spent less time at the landfill with falconry than at another one where a selective culling program was conducted. We conclude that the use of an integrated program using falconry, which we consider more socially acceptable than culling, can be effective in deterring gulls from landfills. Abstract Gulls are commonly attracted to landfills, and managers are often required to implement cost-effective and socially accepted deterrence programs. Our objective was to evaluate the effectiveness of an intensive program that integrated the use of trained birds of prey, pyrotechnics, and playback of gull distress calls at a landfill located close to a large ring-billed gull (Larus delawarensis) colony near Montreal, Quebec, Canada. We used long-term survey data on bird use of the landfill, conducted behavioral observations of gulls during one season and tracked birds fitted with GPS data loggers. We also carried out observations at another landfill located farther from the colony, where less refuse was brought and where a limited culling program was conducted. The integrated program based on falconry resulted in a 98% decrease in the annual total number of gulls counted each day between 1995 and 2014. A separate study indicated that the local breeding population of ring

  10. Breeding productivity of Smith Island black ducks

    USGS Publications Warehouse

    Haramis, G.M.; Jorde, D.G.; Olsen, G.H.; Stotts, D.B.; Harrison, M.K.

    2002-01-01

    We investigated the breeding performance of American black ducks (Anas rubripes) on Smith Island, Chesapeake Bay, to improve our understanding of island black duck breeding ecology and to make management recommendations to enhance productivity. During 1995-96, we implanted 56 female black ducks with 20-g radio transmitters and tracked 35 of the individuals through the breeding season to locate nests, determine nest fate, and identify brood habitat. We also increased preseason banding efforts and compared capture characteristics over 12 years with those from the Deal Island Wildlife Management Area, a banding site on the mainland of Tangier Sound. A low rate of nesting (37%), lack of renesting, and poor hatching success (31%) indicated that island salt marsh habitats present a harsh environment for breeding black ducks. Black ducks located 11 of 13 nests (85%) in black needlerush (Juncus roemerianus) marsh where they were vulnerable to flooding from extreme tides and to egg predators. No nests were found on forested tree hammocks, a feature that distinguishes Smith Island from nearby South Marsh and Bloodsworth Islands. Nest predators included red foxes (Vulpes vulpes), herring gulls (Larus argentams), fish crows (Corvus ossifragus), and, potentially, Norway rats (Rattus norvegicus). Unlike mainland red foxes, foxes radio tracked on Smith Island were found to be capable swimmers and effective low marsh predators. We found shoreline meadows of widgeon grass (Ruppia maritima) to be important foraging sites for black ducks and suspected that the virtual absence of fresh water in this high salinity environment (1217+ ppt) to incur some cost in terms of growth and survival of ducklings. Preseason bandings revealed a high proportion of banded adults and a strong positive correlation in age ratios with the Deal Island banding site. This latter finding strongly suggests a negative universal effect of storm tides on nest success for Tangier Sound black ducks. Management to

  11. Remote sensing: searching for new islands in sea ice.

    PubMed

    Mohr, Johan J; Forsberg, Rene

    2002-03-01

    Tobias Island, discovered in 1993 by the German research vessel RV Polarstern, is a system of low-lying banks and shoals hidden in sea ice 70 km off the northeastern coast of Greenland. Here we use satellite radar interferometry and airborne laser scanning to show that this island is 2 km long and 35 m high --- much larger than was originally reported. We have also been able to pinpoint the exact location of a stable area where a new group of small islands may be hidden. This demonstrates that satellite radar interferometry is an effective tool for finding ice-covered islands as well as for mapping them. PMID:11882882

  12. Exotic invaders gain foraging benefits by shoaling with native fish

    PubMed Central

    Camacho-Cervantes, Morelia; Garcia, Constantino Macías; Ojanguren, Alfredo F.; Magurran, Anne E.

    2014-01-01

    Freshwater habitats are under increasing threat due to invasions of exotic fish. These invasions typically begin with the introduction of small numbers of individuals unfamiliar with the new habitat. One way in which the invaders might overcome this disadvantage is by associating with native taxa occupying a similar ecological niche. Here we used guppies (Poecilia reticulata) from a feral population in Mexico to test the prediction that exotic shoaling fish can associate with heterospecifics, and that they improve their foraging efficiency by doing so. Guppies have invaded the Mexican High Plateau and are implicated in the declines of many native topminnow (Goodeinae) species. We show that heterospecific associations between guppies and topminnows can deliver the same foraging benefits as conspecific shoals, and that variation in foraging gains is linked to differences in association tendency. These results uncover a mechanism enabling founding individuals to survive during the most vulnerable phase of an invasion and help explain why guppies have established viable populations in many parts of Mexico as well in every continent except Antarctica. PMID:26064552

  13. Perfluorinated carboxylates and sulfonates and precursor compounds in herring gull eggs from colonies spanning the Laurentian Great Lakes of North America.

    PubMed

    Gebbink, Wouter A; Hebert, Craig E; Letcher, Robert J

    2009-10-01

    Environmentally important perfluorinated carboxylates and sulfonates, as well as per- and polyfluorinated precursor compounds including several sulfonamides, telomer acids, and alcohols were determined in individual herring gull (Larus argentatus) eggs collected (in 2007) from 15 colonies located at Canadian and some American sites across the Laurentian Great Lakes of North America. The pattern of perfluorosulfonates (PFSAs; C6, C8, C10 chain lengths) was dominated by PFOS (> 90% of sigmaPFSA concentration) regardless of collection location. Concentrations of sigmaPFSA were significantly (p < 0.03) higher in eggs from Middle Island (western Lake Erie; 507 +/- 47 ng/g ww), Toronto Harbour (484 +/- 49 ng/g ww), and Strachan Island (486 +/- 59 ng/g ww) (Lake Ontario) compared to eggs from colonies on Lakes Superior, Michigan, and Huron. Perfluorocarboxylic acids (PFCAs) ranging in chain length from C8 to C15 were detected in the eggs, with PFUnA and PFTrA being the dominant compounds. PFOA and PFNA were more abundant in the sigmaPFCA in eggs from Lake Superior and Michigan colonies, and PFUnA and longer chain PFCAs were more abundant in the sigmaPFCA in eggs from Lake Erie and Ontario colonies. In contrast to sigmaPFSA, the highest concentrations of sigmaPFCA were found in eggs from Double Island, Lake Huron (113 +/- 12 ng/g ww) followed by eggs from colonies on Lakes Erie and Ontario. Among the PFOS or PFCA precursor compounds assessed (6:2, 8:2, and 10:2 fluorotelomer alcohols and acids and PFOSA), none were detectable in eggs from any sampling location. The exception was PFOSA (average concentration < 1 ng/g ww), which suggests that PFOS in the gulls and subsequently in their eggs may be due, in part, to biotransformation of PFOSA to PFOS in the gull and/or in their diet and food web. The accumulation of PFSA and PFCA from mainly aquatic dietary sources was suggested, and were highly lake- and/ or colony-dependent especially showing a northwest and southeast

  14. Evolution of a reassortant North American gull influenza virus lineage: drift, shift and stability

    PubMed Central

    2013-01-01

    Background The role of gulls in the ecology of avian influenza (AI) is different than that of waterfowl. Different constellations of subtypes circulate within the two groups of birds and AI viruses isolated from North American gulls frequently possess reassortant genomes with genetic elements from both North America and Eurasian lineages. A 2008 isolate from a Newfoundland Great Black-backed Gull contained a mix of North American waterfowl, North American gull and Eurasian lineage genes. Methods We isolated, sequenced and phylogenetically compared avian influenza viruses from 2009 Canadian wild birds. Results We analyzed six 2009 virus isolates from Canada and found the same phylogenetic lineage had persisted over a larger geographic area, with an expanded host range that included dabbling and diving ducks as well as gulls. All of the 2009 virus isolates contained an internal protein coding set of genes of the same Eurasian lineage genes except PB1 that was from a North American lineage, and these genes continued to evolve by genetic drift. We show evidence that the 2008 Great Black-backed Gull virus was derived from this lineage with a reassortment of a North American PA gene into the more stable core set of internal protein coding genes that has circulated in avian populations for at least 2 years. From this core, the surface glycoprotein genes have switched several times creating H13N6, H13N2, and H16N3 subtypes. These gene segments were from North American lineages except for the H16 and N3 vRNAs. Conclusions This process appears similar to genetic shifts seen with swine influenza where a stable “triple reassortant internal gene” core has circulated in swine populations with genetic shifts occurring with hemaggluttinin and neuraminidase proteins getting periodically switched. Thus gulls may serve as genetic mixing vessels for different lineages of avian influenza, similar to the role of swine with regards to human influenza. These findings illustrate the

  15. Evolution of a reassortant North American gull influenza virus lineage: drift, shift and stability

    USGS Publications Warehouse

    Hall, Jeffrey S.; TeSlaa, Joshua L.; Nashold, Sean W.; Halpin, Rebecca A.; Stockwell, Timothy; Wentworth, David E.; Dugan, Vivien; Ip, Hon S.

    2013-01-01

    Background: The role of gulls in the ecology of avian influenza (AI) is different than that of waterfowl. Different constellations of subtypes circulate within the two groups of birds and AI viruses isolated from North American gulls frequently possess reassortant genomes with genetic elements from both North America and Eurasian lineages. A 2008 isolate from a Newfoundland Great Black-backed Gull contained a mix of North American waterfowl, North American gull and Eurasian lineage genes. Methods: We isolated, sequenced and phylogenetically compared avian influenza viruses from 2009 Canadian wild birds. Results: We analyzed six 2009 virus isolates from Canada and found the same phylogenetic lineage had persisted over a larger geographic area, with an expanded host range that included dabbling and diving ducks as well as gulls. All of the 2009 virus isolates contained an internal protein coding set of genes of the same Eurasian lineage genes except PB1 that was from a North American lineage, and these genes continued to evolve by genetic drift. We show evidence that the 2008 Great Black-backed Gull virus was derived from this lineage with a reassortment of a North American PA gene into the more stable core set of internal protein coding genes that has circulated in avian populations for at least 2 years. From this core, the surface glycoprotein genes have switched several times creating H13N6, H13N2, and H16N3 subtypes. These gene segments were from North American lineages except for the H16 and N3 vRNAs. Conclusions: This process appears similar to genetic shifts seen with swine influenza where a stable "triple reassortant internal gene" core has circulated in swine populations with genetic shifts occurring with hemaggluttinin and neuraminidase proteins getting periodically switched. Thus gulls may serve as genetic mixing vessels for different lineages of avian influenza, similar to the role of swine with regards to human influenza. These findings illustrate the

  16. Maturation of shoaling behavior is accompanied by changes in the dopaminergic and serotoninergic systems in zebrafish.

    PubMed

    Buske, Christine; Gerlai, Robert

    2012-01-01

    The zebrafish has been one of the preferred vertebrate model organisms of developmental biology, and is becoming an important research tool for behavioral neuroscience and behavior genetics. A prominent feature of zebrafish is their strong shoaling tendency. Most recently, the first study investigating the development of shoaling in zebrafish demonstrated that a few days after hatching zebrafish do not shoal, but that shoaling tendency gradually increases during development. The current study investigates this phenomenon using the nearest neighbor distance, a measure most frequently employed for the quantification of shoal cohesion in fish. We demonstrate that shoal cohesion increases with age, while thigmotaxis, "wall hugging," does not show a consistent age-dependent change. The mechanisms underlying the maturation of shoaling are unknown. HPLC analysis of whole brain extracts finds the concentration of dopamine, DOPAC, serotonin, and 5-HIAA normalized to total brain protein weight to increase with age. Although the behavioral and neurochemical results are only correlative at this point, they may open a new avenue into the investigation of the mechanisms and development of social behavior in zebrafish. PMID:21656763

  17. Chiral organochlorine contaminants in blood and eggs of glaucous gulls (Larus hyperboreus) from the Norwegian Arctic.

    PubMed

    Ross, Matthew S; Verreault, Jonathan; Letcher, Robert J; Gabrielsen, Geir W; Wong, Charles S

    2008-10-01

    Glaucous gulls (Larus hyperboreus) and their eggs from Svalbard (Norwegian Arctic) have been used as biomonitors of contaminants in the marine environment. In this study, the enantiomer fractions (EFs) of chiral chlordanes and atropisomeric polychlorinated biphenyl (PCB) congeners were determined in the blood plasma of adult male and female glaucous gulls from three breeding colonies in Svalbard. Plasma EFs were similar in magnitude and direction to EFs previously reported in glaucous gulls from other arctic food webs, suggesting overall similarities in the biochemical processes influencing the EFs of bioaccumulated organochlorine (OC) contaminants within the food webs at those locations. Additionally, EFs in yolk of eggs collected concurrently from within the same nesting colonies varied with location, laying date, and OC concentrations, and may be influenced by changes in the local feeding ecology between those colonies. No differences were found between the EFs for any analyte in female gulls compared to those found in egg yolk, indicating that processes involved in the maternal transfer of chlordanes and PCBs to eggs do not modulate the stereochemical ratio between enantiomers. Therefore, the use of eggs as a valuable and noninvasive means of OC biomonitoring may also extend to enantiomer compositions in glaucous gulls, and perhaps also in other seabird species from arctic regions. PMID:18939544

  18. Erysipelothrix rhusiopathiae isolated from gull-inflicted wounds in southern right whale calves.

    PubMed

    Fiorito, Carla D; Bentancor, Adriana; Lombardo, Daniel; Bertellotti, Marcelo

    2016-08-31

    Southern right whales Eubalaena australis from Peninsula Valdés, Argentina, show wounds produced by kelp gulls Larus dominicanus that feed on the whales' dorsal skin and blubber. During the 2013 whale season, several calves were reported showing kelp gull injuries with a swollen area surrounded by rhomboid-shaped raised edges. Samples from 9 calves were taken in order to establish the etiology of these rhomboid-shaped wounds; 2 calves (one living, one dead) showed gull-inflicted injuries with rhomboid-shaped edges. Samples from the dead calf were histologically characterized by the presence of dermal congestion, suppurative dermatitis and panniculitis, necrotizing vasculitis and vascular thrombosis. Erysipelothrix rhusiopathiae was detected by culture and PCR in samples from both calves. In this study we report, for the first time to our knowledge, the isolation of E. rhusiopathiae from wounds produced by gull attacks on southern right whale calves, supplying evidence that these wounds may act as an entry route for pathogens. This work provides new information about the consequences of gull-inflicted injuries for whale health. PMID:27596861

  19. Experimental infection and pathology of clade 2.2 H5N1 virus in gulls.

    PubMed

    Gulyaeva, Marina A; Sharshov, Kirill A; Zaykovskaia, Anna V; Shestopalova, Lidia V; Shestopalov, Aleksander M

    2016-06-30

    During 2006, H5N1 HPAI caused an epizootic in wild birds, resulting in a die-off of Laridae in the Novosibirsk region at Chany Lake. In the present study, we infected common gulls (Larus canus) with a high dose of the H5N1 HPAI virus isolated from a common gull to determine if severe disease could be induced over the 28 day experimental period. Moderate clinical signs including diarrhea, conjunctivitis, respiratory distress and neurological signs were observed in virus-inoculated birds, and 50% died. The most common microscopic lesions observed were necrosis of the pancreas, mild encephalitis, mild myocarditis, liver parenchymal hemorrhages, lymphocytic hepatitis, parabronchi lumen hemorrhages and interstitial pneumonia. High viral titers were shed from the oropharyngeal route and virus was still detected in one bird at 25 days after infection. In the cloaca, the virus was detected sporadically in lower titers. The virus was transmitted to direct contact gulls. Thus, infected gulls can pose a significant risk of H5N1 HPAIV transmission to other wild migratory waterfowl and pose a risk to more susceptible poultry species. These findings have important implications regarding the mode of transmission and potential risks of H5N1 HPAI spread by gulls. PMID:26243601

  20. Functional Metagenomics Reveals Previously Unrecognized Diversity of Antibiotic Resistance Genes in Gulls

    PubMed Central

    Martiny, Adam C.; Martiny, Jennifer B. H.; Weihe, Claudia; Field, Andrew; Ellis, Julie C.

    2011-01-01

    Wildlife may facilitate the spread of antibiotic resistance (AR) between human-dominated habitats and the surrounding environment. Here, we use functional metagenomics to survey the diversity and genomic context of AR genes in gulls. Using this approach, we found a variety of AR genes not previously detected in gulls and wildlife, including class A and C β-lactamases as well as six tetracycline resistance gene types. An analysis of the flanking sequences indicates that most of these genes are present in Enterobacteriaceae and various Gram-positive bacteria. In addition to finding known gene types, we detected 31 previously undescribed AR genes. These undescribed genes include one most similar to an uncharacterized gene in Verrucomicrobium and another to a putative DNA repair protein in Lactobacillus. Overall, the study more than doubled the number of clinically relevant AR gene types known to be carried by gulls or by wildlife in general. Together with the propensity of gulls to visit human-dominated habitats, this high diversity of AR gene types suggests that gulls could facilitate the spread of AR. PMID:22347872

  1. Does garbage in the diet improve reproductive output of Glaucous Gulls

    USGS Publications Warehouse

    Weiser, E.L.; Powell, A.N.

    2010-01-01

    Anthropogenic subsidies are used by a variety of predators in areas developed for human use or residence. If subsidies promote population growth, these predators can have a negative effect on local prey species. The Glaucous Gull (Larus hyperboreus) is an abundant predator in northern Alaska that is believed to benefit from garbage as a supplemental food source, but this supposition has never been tested. In summer 2008 and 2009, we recorded the Glaucous Gull's diet and reproduction at 10 breeding colonies in northern Alaska. Colonies were in industrial, residential, and undeveloped areas and ranged from 5 to 75 km from the nearest landfill. By colony, garbage occurred in zero to 85% of pellets and food remains produced during the chick-rearing period, and the average number of chicks fledged per pair ranged from zero to 2.9. Random-forest analysis indicated that percent occurrence of garbage in the diet was the second most important factor (after number of eggs per pair) explaining variance in fledging rate. There was a significant positive correlation between percent occurrence of garbage in the diet and fledging rate in each year. If this correlation reflects a causal relationship, it suggests that human development that increases gulls' access to garbage could result in increased local gull populations. Such an increase could affect the gulls' natural prey species, including at least 14 species of shorebirds and waterfowl of conservation concern. ?? The Cooper Ornithological Society 2010.

  2. Antibodies to Influenza A Viruses in Gulls at Delaware Bay, USA.

    PubMed

    Guinn, Kayla; Fojtik, Alinde; Davis-Fields, Nick; Poulson, Rebecca L; Krauss, Scott; Webster, Robert G; Stallknecht, David E

    2016-05-01

    Gulls are the known reservoir for H13 and H16 influenza A viruses (IAV) but also host a diversity of other IAV subtypes. Gulls also share habitats with both ducks and shorebirds, increasing the potential for cross-species IAV transmission. We serologically tested laughing gulls (Leucophaeus atricilla) collected at Delaware Bay during May when they were in direct contact with IAV-infected shorebirds; both species feed on horseshoe crab (Limulus polyphemus) eggs on beaches during this month. From 2010 to 2014, antibody prevalence as determined by competitive blocking enzyme-linked immunosorbent assay ranged from 25%-72%. Antibodies to H13 and H16 were detected by hemagglutination inhibition (HI) tests in 12% and 24% of tested gulls, respectively. Results from virus microneutralization (MN) tests for antibodies to H1-H12, H14, and H15 varied among years but the highest prevalence of neutralizing antibodies was detected against H1 (24%), H5 (25%), H6 (35%), H9 (33%), and H11 (42%) IAV. The subtype diversity identified by serology in gulls was dominated by Group 1 HA subtypes and only partially reflected the diversity of IAV subtypes isolated from shorebirds. PMID:27309077

  3. An outbreak of type C botulism in Herring Gulls (Larus argentatus) in Southeastern Sweden

    USGS Publications Warehouse

    Neimanis, A.; Gavier-Widen, D.; Leighton, F.; Bollinger, T.; Rocke, T.; Morner, T.

    2007-01-01

    From 2000 to 2004, over 10,000 seabirds, primarily Herring Gulls (Larus argentatus), died from an undetermined cause in the Blekinge archipelago in southeastern Sweden. In June 2004, 24 affected Herring Gulls were examined clinically, killed humanely, and 23 were examined by necropsy. Seven and 10 unaffected Herring Gulls collected from a local landfill site and from Iceland, respectively, served as controls. All affected birds showed similar neurologic signs, ranging from mild incoordination and weakness to severe flaccid paralysis of legs and wings, but generally were alert and responsive. All affected gulls were in normal nutritional condition, but were dehydrated and had empty stomachs. No gross or microscopic lesions, and no bacterial or viral pathogens were identified. Type C botulinum toxin was detected in the sera of 11 of 16 (69%) affected gulls by mouse inoculation. Type C botulism was the proximate cause of disease in 2004. Sera from 31% of birds tested from outbreaks in 2000 to 2003 also had detectable type C botulinum toxin by mouse inoculation. No large-scale botulism outbreak has been documented previously in this area. The source of toxin, initiating conditions, and thus, the ultimate cause of this outbreak are not known. This epidemic might signal environmental change in the Baltic Sea. ?? Wildlife Disease Association 2007.

  4. Experimental infection and pathology of clade 2.2 H5N1 virus in gulls

    PubMed Central

    Gulyaeva, Marina A.; Zaykovskaia, Anna V.; Shestopalova, Lidia V.; Shestopalov, Aleksander M.

    2016-01-01

    During 2006, H5N1 HPAI caused an epizootic in wild birds, resulting in a die-off of Laridae in the Novosibirsk region at Chany Lake. In the present study, we infected common gulls (Larus canus) with a high dose of the H5N1 HPAI virus isolated from a common gull to determine if severe disease could be induced over the 28 day experimental period. Moderate clinical signs including diarrhea, conjunctivitis, respiratory distress and neurological signs were observed in virus-inoculated birds, and 50% died. The most common microscopic lesions observed were necrosis of the pancreas, mild encephalitis, mild myocarditis, liver parenchymal hemorrhages, lymphocytic hepatitis, parabronchi lumen hemorrhages and interstitial pneumonia. High viral titers were shed from the oropharyngeal route and virus was still detected in one bird at 25 days after infection. In the cloaca, the virus was detected sporadically in lower titers. The virus was transmitted to direct contact gulls. Thus, infected gulls can pose a significant risk of H5N1 HPAIV transmission to other wild migratory waterfowl and pose a risk to more susceptible poultry species. These findings have important implications regarding the mode of transmission and potential risks of H5N1 HPAI spread by gulls. PMID:26243601

  5. Sex biases in kin shoaling and dispersal in a cichlid fish.

    PubMed

    van Dongen, Wouter F D; Wagner, Richard H; Moodley, Yoshan; Schaedelin, Franziska C

    2014-12-01

    Animal dispersal is associated with diverse costs and benefits that vary among individuals based on phenotype and ecological conditions. For example, females may disperse when males benefit more from defending territories in familiar environments. Similarly, size differences in dispersal propensity may occur when dispersal costs are size-dependent. When individuals do disperse, they may adopt behavioral strategies that minimize dispersal costs. Dispersing fish, for example, may travel within shoals to reduce predation risks. Further, kin shoaling may augment inclusive fitness by reducing predation of relatives. However, studies are lacking on the role of kin shoaling in dispersal. We explored how sex and size influence dispersal and kin shoaling in the cichlid Neolamprologus caudopunctatus. We microsatellite genotyped over 900 individuals from two populations separated by a potential dispersal barrier, and documented patterns of population structure, migration and within-shoal relatedness. Genetic differentiation across the barrier was greater for smaller than larger fish, suggesting larger fish had dispersed longer distances. Females exhibited weaker genetic differentiation and 11 times higher migration rates than males, indicating longer-distance female-biased dispersal. Small females frequently shoaled with siblings, possibly offsetting dispersal costs associated with higher predation risks. In contrast, small males appeared to avoid kin shoaling, possibly to avoid local resource competition. In summary, long-distance dispersal in N. caudopunctatus appears to be female-biased, and kin-based shoaling by small females may represent a behavioral adaptation that reduces dispersal costs. Our study appears to be the first to provide evidence that sex differences in dispersal influence sex differences in kin shoaling. PMID:25231372

  6. Heavy metals in laughing gulls: Gender, age and tissue differences

    SciTech Connect

    Gochfeld, M. |; Belant, J.L.; Shukla, T.; Benson, T.; Burger, J. |

    1996-12-01

    The authors examined concentrations of lead, cadmium, mercury, manganese, selenium, and chromium in feathers, liver, kidney, heart, and muscle of known-aged laughing gulls (Larus atricilla) that hatched in Barnegat Bay, New Jersey and were collected at John F. Kennedy International Airport, New York 1 to 7 years later. Concentrations differed significantly among tissues, and tissue entered all the regression models explaining the greatest variation in metal levels. Age of bird contributed significantly to the models for lead, cadmium, selenium, and chromium. Although there were significant gender differences in all body measurements except wing length, there were few differences in metal levels. Males had significantly higher lead levels in feathers, and females had significantly higher selenium levels in heart and muscle tissue. For lead, 3-year olds had the highest levels in the heart, liver, and kidney, and levels were lower thereafter. Mercury levels in feathers and heart decreased significantly with age. Cadmium levels increased significantly with age for feathers, heart, liver, and muscle, although there was a slight decrease in the 7-year olds. Selenium levels decreased significantly with age for all tissues. Chromium levels increased with age for liver and heart.

  7. Distribution and potential significance of a gull fecal marker in urban coastal and riverine areas of southern Ontario, Canada

    EPA Science Inventory

    To better understand the distribution of gull fecal contamination in urban areas of southern Ontario, we used a gull-targeted PCR assay against 1309 water samples collected from 15 urban coastal and riverine locations during 2007. Approximately, 58 % of the water samples tested w...

  8. Structural characteristics of the Relict Gull (Larus relictus) mitochondrial DNA control region and its comparison to other Laridae.

    PubMed

    Yang, Chao; Lian, Ting; Wang, Qing-Xiong; Huang, Yuan; Xiao, Hong

    2016-07-01

    The structure of the mitochondrial DNA control region in the Relict Gull (Larus relictus) was predicted and compared with data from the National Center for Biotechnology Information (NCBI) on five other gulls. The results showed that the control regions of the six gulls comprise three domains. Sequences of CSB-1-like (domain I) and CSB-1 (domain III) in L. relictus have the highest similarity with those in the other five gulls. The insertion fragments are located in downstream domain I of L. ridibundus, L. brunnicephalus, and L. saundersi. Seven conserved sequence boxes (additional box, F-box, E-box, D-box, C-box, bird-similarity-box, and B-box) are located in domain II in all six gulls. It is suggested that the CSB-2/3 sequence, the origin of H-strand replication, and bidirectional light- and heavy-strand transcription promoters in domain III of L. relictus have some distinguishing features to those of other gulls. Some repeat units are contained in the 3' end of the control region in the five gulls; however, no repeat units are found in the sequence CAAACAACAAA in L. relictus. The distribution of nucleotide diversity analysis will provide the useful information on the selected DNA fragment within the control region for genetic analyses among gulls. PMID:26016878

  9. Predator-prey relations and competition for food between age-0 lake trout and slimy sculpins in the Apostle Island region of Lake Superior

    USGS Publications Warehouse

    Hudson, Patrick L.; Savino, Jacqueline F.; Bronte, Charles R.

    1995-01-01

    Slimy sculpins (Cottus cognatus) are an important component of the fish community on reefs and adjacent nursery areas of the Great Lakes and overlap spatially with age-0 lake trout (Salvelinus namaycush). Important interactions between these fishes are possible during the lake trout's first year of life, which could include predation on each other's eggs and larvae, and competition for food resources. We investigated the diets of age-0 lake trout and slimy sculpins on a lake trout spawning reef (Gull Island Shoal) and adjacent nursery area (near Michigan Island) in the Apostle Island region of western Lake Superior during June through September from 1988 through 1991. Organisms in stomachs of 511 lake trout and 562 sculpins were identified and counted. Of the 11 major food types found in age-0 lake trout stomachs from both areas, Mysis was the dominant food item (mean volume in stomachs = 68%) and occurred in about 3/4 of the fish analyzed. Copepods, cladocerans, chironomid pupae, fish, and Bythotrephes were also common in the diet (frequency of occurrence > 4%). Diets of lake trout were more diverse on the reef than on the nursery area where Mysis dominated the diet. Slimy sculpins were only found in lake trout greater than 50 mm. Mysis was an important food item of slimy sculpins over the reef but not over the nursery area, where Diporeia was by far the most important taxon. A variety ofben-thic invertebrates (Asellus, chironomids, benthic copepods, and snails) comprised the bulk of the sculpin diet over the reef. Sculpins also ate lake trout eggs in November. Based on cluster analysis, diets were most similar over the reef where both consumed Mysis, calanoid copepods and chironomid pupae. Diets diverged over the nursery areas where sculpins were strictly benthic feeders and lake trout maintained their planktonic diet. In Lake Superior, where lake trout recruitment through natural reproduction has become well established, the coexistence of the two

  10. Groundwater Monitoring Report Project Shoal Area, Corrective Action Unit 447

    SciTech Connect

    2008-01-01

    This report presents the 2007 groundwater monitoring results collected by the U.S. Department of Energy (DOE) Office of Legacy Management (LM) at the Project Shoal Area (PSA) Corrective Action Unit (CAU) 447 located in Churchill County, Nevada. Responsibility for the environmental site restoration of the PSA was transferred from the DOE Office of Environmental Management (DOE-EM) to DOE-LM on October 1, 2006. Requirements for CAU 447, as specified in the Federal Facility Agreement and Consent Order (FFACO 2005) entered into by DOE, the U.S. Department of Defense (DOD), and the State of Nevada, includes groundwater monitoring in support of site closure. This is the first groundwater monitoring report prepared by DOE-LM for the PSA.

  11. Closure report for CAU No. 416: Project Shoal Area

    SciTech Connect

    1998-01-01

    This Closure Report provides the documentation for closure of the US Department of Energy/Nevada Operations Office (DOE/NV) Project Shoal Area (PSA) Surface Corrective Action Unit (CAU) 416. CAU 416 consists of a mud pit, muckpile, and housekeeping site. The PSA is located approximately 48.3 kilometers (30 miles) southeast of Fallon, Nevada. The mud pit was the result of drilling activities at the PSA in 1963. Investigation activities completed in 1996 determined drilling mud in the mud pit was impacted with petroleum hydrocarbons in excess of the State of Nevada 100 milligram per kilogram (mg/kg). The muckpile consists of broken granite from emplacement shaft and drift (tunnel) mining activities at the PSA in 1963. The housekeeping site consisted of approximately 20 used, empty, rusted, steel 0.9 liter (1 quart) oil cans.

  12. Androgen response to social competition in a shoaling fish.

    PubMed

    Teles, Magda C; Oliveira, Rui F

    2016-02-01

    Androgens respond to social challenges and this response has been interpreted as a way for males to adjust androgen-dependent behavior to social context. However, the androgen responsiveness to social challenges varies across species and a conceptual framework has been developed to explain this variation according to differences in the mating system and parental care type, which determines the regimen of challenges males are exposed to, and concomitantly the scope (defined as the difference between the physiological maximum and the baseline levels) of response to a social challenge. However, this framework has been focused on territorial species and no clear predictions have been made to gregarious species (e.g. shoaling fish), which although tolerating same-sex individuals may also exhibit intra-sexual competition. In this paper we extend the scope of this conceptual framework to shoaling fish by studying the endocrine response of zebrafish (Danio rerio) to social challenges. Male zebrafish exposed to real opponent agonistic interactions exhibited an increase in androgen levels (11-ketotestosterone both in Winners and Losers and testosterone in Losers). This response was absent in Mirror-fighters, that expressed similar levels of aggressive behavior to those of winners, suggesting that this response is not a mere reflex of heightened aggressive motivation. Cortisol levels were also measured and indicated an activation of the hypothalamic-pituitary-interrenal axis in Winners of real opponent fighters, but not Losers or in Mirror-fighters. These results confirm that gregarious species also exhibit an endocrine response to an acute social challenge. PMID:26497408

  13. Nesting biology of laughing gulls Larus atricilla in relation to agricultural chemicals in south Texas USA 1978-1981

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Prouty, R.M.

    1983-01-01

    Various aspects of the breeding biology of Laughing Gulls (Larus atricilla) have been studied extensively in Florida (Dinsmore and Schreiber 1974, Schreiber et al. 1979, Schreiber and Schreiber 1980), New Jersey (Bongiorno 1970, Burger and Beer 1976, Burger 1976, Montevecchi 1978), and Massachusetts (Noble and Wurm 1943), but little is known of their yearly fledging success in Texas or elsewhere. The Laughing Gull is a common colonial nester along most of the Texas coast, second only to the Cattle Egret (Bubulcus ibis) in breeding abundance; however, the Laughing Gull may be threatened in Texas because of suspected declines at certain traditional nesting locales (Blacklock et al. 1979). Since Laughing Gulls often nest in proximity to agricultural and industrial areas, we were concerned that environmental pollutants might be adversely affecting productivity. In 1978-1981 we conducted studies along the south Texas coast to learn more about the nesting ecology of Laughing Gulls and to evaluate the effects of environmental contaminants on reproduction.

  14. Dynamics of storage of organochlorine pollutants in herring gulls

    USGS Publications Warehouse

    Anderson, D.W.; Hickey, J.J.

    1976-01-01

    Several organochlorine pollutants were studied over the period of one annual cycle in caged juvenile and wild-collected adult herring gulls (Lagus argentatus) from Lake Michigan. Fish, mostly alewives (Alosa pseudoharengus), comprised the major year-round food items in the wild; alewives were also fed to the caged juveniles. Fish residues averaged around 3 mg/kg of p,p'-DDE, 2 mg/kg p,p'DDT + p,p'-TDE, and 2 mg/kg apparent PCBs. Juvenile body-burdens of DDE and PCBs showed a continual buildup after fledging, then a temporary dynamic equilibrium, related only in part to annual lipid deposition. Maximum body-burdens were reached in both juveniles and adults when winter fat deposits were declining prior to the breeding season?followed by a return to dynamic equilibrium. Residues of DDT and TDE followed closely the annual pattern of lipid deposition in both juveniles and adults. Total body-burdens in both age classes were similar after the buildups to equilibrium in juveniles in their eighth month after fledging. Seasonal variations of residues of DDE and PCBs were characterised by two phases in adults and three in juveniles, which gradually assumed the adult cyclic pattern. The maximum body-burdens attained by caged juveniles fed a diet of Lake Michigan alewives were 290 mg/kg DDE, 19 mg/kg DDT + TDE, and 200 mg/kg apparent PCBs. Residues in wild adults at the same time were 300, 4, and 200 mg/kg of the same residues. Apparent PCBs and DDE were highly accumulative, although DDE levels resulted from dietary DDE, as well as conversion from DDT.

  15. Recent social environment affects colour-assortative shoaling in juvenile angelfish (Pterophyllum scalare).

    PubMed

    Gómez-Laplaza, Luis M

    2009-09-01

    Theory predicts that fish should show colour-assortative shoaling in order to avoid the oddity effect whereby individuals that differ in some feature from the group majority appear to incur increased risk of predation. It has also been shown that early experience plays an important role in affecting social preferences in some fish species. In this study, the importance of colour phenotype in promoting assortative shoaling and the role played by the recent social environment on its expression were investigated in juvenile angelfish, Pterophyllum scalare. Individuals of the uniformly black and golden colour morphs were housed in a group with conspecifics of like and unlike body colour to themselves, as well as in mixed-colour groups for 4 weeks. Subsequently, they were subjected to a binary choice to shoal with a group of conspecifics composed of unfamiliar fish of either a like or unlike colour phenotype to themselves. The response of the individuals to the colour attributes of the shoals was related to their recent social environment. Fish in like- and mixed-colour previous treatments showed a preferential association with like colour conspecifics. In contrast, the shoaling behaviour exhibited by fish previously maintained with a group of unlike-coloured conspecifics (cross-housed treatment) indicated no significant preference for any of the shoals. The results suggest that angelfish use body colouration as an intraspecific shoaling cue and that learning, in the form of recent familiarization with a specific colour phenotype of conspecifics, can affect colour-assortative shoaling preferences in this species. This learning component of the choice need not be restricted to early developmental stages. PMID:19376208

  16. Hybridization threatens shoal bass populations in the Upper Chattahoochee River Basin: Chapter 37

    USGS Publications Warehouse

    Dakin, Elizabeth E; Porter, Brady A.; Freeman, Byron J.; Long, James M.

    2015-01-01

    Shoal bass are native only to the Apalachicola-Chattahoochee-Flint river system of Georgia, Alabama, and Florida, and are vulnerable to extinction as a result of population fragmentation and introduction of non-native species. We assessed the genetic integrity of isolated populations of shoal bass in the upper Chattahoochee River basin (above Lake Lanier, Big Creek, and below Morgan Falls Dam) and sought to identify rates of hybridization with non-native, illegally stocked smallmouth bass and spotted bass.

  17. Fish Cam: An Online Tool for Introducing Shoaling Behavior to the Classroom

    PubMed Central

    Southwell, Maura; Galassi, Maria

    2012-01-01

    Abstract Fish Cam is an on-line educational resource that enables students to participate in behavioral research projects without ever leaving their classroom. By linking onto the Fish Cam site, students will observe an experimental tank in which fish choose shoal-mates in dichotomous choice tests. In these experiments, a test fish, in the central compartment, displays its shoaling preference by swimming near small shoals of fish in either of two side compartments. Assays are designed to examine the effects of phenotype, shoal size, and other factors known to influence shoaling. Students monitor Fish Cam in real time, and students collect data simply by running timers when the test fish crosses into the preference zones at each end of the central compartment. The times are logged onto data sheets that we provide, and we assist the students with their analysis. The simplicity of shoaling behavior makes it an ideal model system for data collection that is accessible to students of all ages and, in its first few years of operation, Fish Cam studies have been performed by fifth-, seventh- and eleventh-grade students. Sample lesson plans and handouts are available online to enhance the Fish Cam experience. The ultimate goals of this project are to make scientific research accessible in the classroom and promote science education. PMID:23244694

  18. Fish cam: an online tool for introducing shoaling behavior to the classroom.

    PubMed

    Southwell, Maura; Galassi, Maria; McRobert, Scott

    2012-12-01

    Fish Cam is an on-line educational resource that enables students to participate in behavioral research projects without ever leaving their classroom. By linking onto the Fish Cam site, students will observe an experimental tank in which fish choose shoal-mates in dichotomous choice tests. In these experiments, a test fish, in the central compartment, displays its shoaling preference by swimming near small shoals of fish in either of two side compartments. Assays are designed to examine the effects of phenotype, shoal size, and other factors known to influence shoaling. Students monitor Fish Cam in real time, and students collect data simply by running timers when the test fish crosses into the preference zones at each end of the central compartment. The times are logged onto data sheets that we provide, and we assist the students with their analysis. The simplicity of shoaling behavior makes it an ideal model system for data collection that is accessible to students of all ages and, in its first few years of operation, Fish Cam studies have been performed by fifth-, seventh- and eleventh-grade students. Sample lesson plans and handouts are available online to enhance the Fish Cam experience. The ultimate goals of this project are to make scientific research accessible in the classroom and promote science education. PMID:23244694

  19. Mutagenicity studies on herring gulls from different locations on the Great Lakes. I. Sister chromatid exchange rates in herring-gull embryos.

    PubMed

    Ellenton, J A; McPherson, M F

    1983-01-01

    Unincubated herring-gull (Larus argentatus) eggs were collected from five colonies on the Great Lakes Basin and from one relatively pollutant-clean colony on the Atlantic coast. Eggs were incubated at 38 degrees C with 55% relative humidity, and sister chromatid exchange (SCE) levels were measured in 7-d embryos. For all of the colonies, the average SCE/chromosome frequency ranged from 0.069 to 0.101; however, no significant differences were found. Organochlorine analysis was carried out on egg homogenates for each colony, to determine the levels of several contaminants. There were no relationships found between any of the contaminant levels and the SCE frequencies. The study indicates that either the contaminants present in the herring-gull eggs are not having any genetic effects on the embryos or, alternatively, that there may be genetic damage that measurement of SCEs in the 7-d embryo is unable to detect. PMID:6655738

  20. Sediment Delivery to Diamond Shoals: a Field Experiment at Cape Hatteras Point, North Carolina (Invited)

    NASA Astrophysics Data System (ADS)

    List, J. H.; Warner, J. C.; Thieler, E. R.; Haas, K. A.; Voulgaris, G.; McNinch, J. E.; Brodie, K. L.

    2010-12-01

    Diamond Shoals is a complex of sand shoals extending more than 20 km seaward from Cape Hatteras Point, North Carolina. We conducted a one-month field experiment at Cape Hatteras Point during February 2010, with a primary objective of quantifying the processes that deliver sediment to Diamond Shoals. A leading hypothesis from previous literature, mainly focused on the similar Cape Lookout Shoals, is that wave-driven nearshore currents on the coasts flanking the cape deliver sand to the proximal (near coast) part of the shoal, and flows with the potential to return sand to one of the flanking shorelines have less capacity. The shoal is hypothesized to be a long-term sediment sink because of this transport asymmetry. We deployed wave- and current-measuring instruments in the nearshore and installed several types of remote sensing devices around Cape Hatteras Point. Remote sensing devices included a video camera mounted on the Cape Hatteras lighthouse to measure nearshore surface currents and a VHF (48MHz) WERA (WEllen RAdar) station for measuring wide-area (O: 10 km) surface currents over Diamond Shoals. Ground-based lidar topography, wide-area wave dissipation intensity, wave direction, and bathymetry were measured by the CLARIS (Coastal Lidar And Radar Imaging System) and LARC (Lighter Amphibious Resupply Cargo) surveying systems. A shoreline change analysis is used to quantify the cape’s recent morphologic evolution and previous geophysical surveys provide information on the shoal’s thickness and geologic framework. Wind and wave directions during the experiment were similar to the long-term climatology, with principal components from the north/northeast and west/southwest. Results from the nearshore instrumentation show that north/northeast conditions force mean currents from the north side of the cape toward the shoal and west/southwest conditions force currents from the south side of the cape toward the shoal. The very shallow water over Diamond Shoals (in

  1. Reduction of garbage in the diet of nonbreeding glaucous gulls corresponding to a change in waste management

    USGS Publications Warehouse

    Weiser, E.L.; Powell, A.N.

    2011-01-01

    Glaucous gulls (Larus hyperboreus) are major predators in the Arctic and may benefit from human development. We studied use of garbage by glaucous gulls in Barrow, Alaska, in 2007, when municipal waste was disposed of in a landfill, and in 2008, when it was incinerated. In both years, diet samples from breeding adult gulls contained less garbage than those from loafing nonbreeding gulls (mostly subadults of less than four years), possibly because the breeding colony was more distant than many loafing sites from the landfills. Although breeding gull samples showed no change, garbage in regurgitated pellets and food remains of nonbreeding gulls was significantly less prevalent in 2008 than in 2007 (28% vs. 43% occurrence in diet samples), and this reduction could be explained by the switch from landfill to waste incineration. Yet garbage remained a substantial part of nonbreeding gull diet after the management change. Other aspects of waste management, such as storage prior to disposal, may also be important in limiting scavengers' access to garbage and thus reducing the indirect impact of human development on prey species of conservation concern. ?? The Arctic Institute of North America.

  2. New organochlorine contaminants and metabolites in plasma and eggs of glaucous gulls (Larus hyperboreus) from the Norwegian Arctic.

    PubMed

    Verreault, Jonathan; Letcher, Robert J; Muir, Derek C G; Chu, Shaogang; Gebbink, Wouter A; Gabrielsen, Geir W

    2005-10-01

    The present study investigated new or lesser-studied and legacy organochlorine (OC) contaminants and metabolites in plasma and eggs of glaucous gulls (Larus hyperboreus) collected from major breeding colonies on Bear Island in the Norwegian Arctic. Hexachlorobutadiene was below the method limit of detection (< 0.07 ng/g lipid wt) in all samples. The sum (sum) of 20 chlorobornane congener concentrations ranged between 294 and 986 ng/g lipid weight and 104 and 1,121 ng/g lipid weight in plasma and eggs, respectively, whereas those of sum 20polychlorinated naphthalene ranged between 1.34 and 126 ng/g lipid weight in plasma and 1.82 and 162 ng/g lipid weight in eggs. Bis(4-chlorophenyl) sulfone concentrations ranged between 5.24 and 143 ng/ g lipid weight plasma, which is the first report of this contaminant in arctic biota north of Sweden. Based on 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs), partial dioxin-like toxicity varied between 3.04 and 20.8 ng TEQ/g lipid weight in plasma and 0.94 and 46.5 ng TEQ/g lipid weight in eggs, and largely was due to concentrations of non-ortho polychlorinated biphenyls (PCBs), with a very minor contribution from mono-ortho PCBs and polychlorinated naphthalenes. The major aryl sulfone metabolite in plasma was an unidentified hexachlorinated MeSO2-PCB congener (range: 13.5-551 ng/g lipid wt), whereas the pentachlorinated congeners 3'- and 4'-MeSO2-CB101 (range: 4.49-38.1 ng/g lipid wt) dominated in eggs. The predominant halogenated phenolic compound (HPC) in plasma was consistently the PCB metabolite 4-OH-CB187 (range: 0.29-17.5 ng/g wet wt), whereas in eggs, detectable HPCs were at very low and transient concentrations. As part of a complex profile of contaminant exposure, these chemical classes and metabolites may be contributing factors to enhance physiological stress in breeding glaucous gulls. PMID:16268150

  3. Immunological and reproductive health assessment in herring gulls and black-crowned night herons in the Hudson-Raritan Estuary.

    PubMed

    Grasman, Keith A; Echols, Kathy R; May, Thomas M; Peterman, Paul H; Gale, Robert W; Orazio, Carl E

    2013-03-01

    Previous studies have shown inexplicable declines in breeding waterbirds within western New York/New Jersey Harbor between 1996 and 2002 and elevated polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls (PCBs) in double-crested cormorant (Phalacrocorax auritus) eggs. The present study assessed associations between immune function, prefledgling survival, and selected organochlorine compounds and metals in herring gulls (Larus argentatus) and black-crowned night herons (Nycticorax nycticorax) in lower New York Harbor during 2003. In pipping gull embryos, lymphoid cells were counted in the thymus and bursa of Fabricius (sites of T and B lymphocyte maturation, respectively). The phytohemagglutinin (PHA) skin response assessed T cell function in gull and heron chicks. Lymphocyte proliferation was measured in vitro in adult and prefledgling gulls. Reference data came from the Great Lakes and Bay of Fundy. Survival of prefledgling gulls was poor, with only 0.68 and 0.5 chicks per nest surviving to three and four weeks after hatch, respectively. Developing lymphoid cells were reduced 51% in the thymus and 42% in the bursa of gull embryos from New York Harbor. In vitro lymphocyte assays demonstrated reduced spontaneous proliferation, reduced T cell mitogen-induced proliferation, and increased B cell mitogen-induced proliferation in gull chicks from New York Harbor. The PHA skin response was suppressed 70 to 80% in gull and heron chicks. Strong negative correlations (r = -0.95 to -0.98) between the PHA response and dioxins and PCBs in gull livers was strong evidence suggesting that these chemicals contribute significantly to immunosuppression in New York Harbor waterbirds. PMID:23212976

  4. Changes in food web structure affect rate of PCB decline in herring gull (Larus argentatus) eggs

    SciTech Connect

    Hebert, C.E.; Hobson, K.A.; Shutt, J.L.

    2000-05-01

    Biological monitors provide important information regarding temporal trends in levels of persistent organic pollutants. Correct interpretation of these trends is critical if one is to accurately assess his progress in eliminating these contaminants from the environment. In the Laurentian Great Lakes, polychlorinated biphenyl concentrations in herring gull eggs declined during the 1970s and early 1980s. By the mid-1980s, further declines were not as obvious. An exception to this trend was observed in eggs from Lake Erie. On that lake, egg PCB concentrations continued to decline rapidly during the 1980s/1990s. Evidence from stable isotope analysis indicated that temporal changes in the composition of the herring gull diet occurred on Lake Erie. In the eastern basin, declines in fish availability may have forced the gulls to incorporate a greater proportion of terrestrial food into their diets. Decreases in the proportion of fish in the gull diet would have resulted in reduced PCB exposure. This may be partially responsible for the continuing rapid rate of decline in egg PCB concentrations. This decline should be interpreted with caution. These trends may not be indicative of lake-wide declines in PCB bioavailability but only reflect changes in dietary exposure brought about by alterations in food web structure.

  5. Comparative susceptibility of waterfowl and gulls to highly pathogenic avian influenza H5N1 virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild avian species in the Orders Anseriformes (ducks, geese, swans) and Charadriiformes (gulls, terns, shorebirds) have traditionally been considered the natural reservoirs for avian influenza viruses (AIV) and morbidity or mortality is rarely associated with AIV infection in these hosts. However, ...

  6. A Communicative Analysis of Chekhovian Drama as Portrayed in "The Sea Gull."

    ERIC Educational Resources Information Center

    Hellweg, John D.; Hellweg, Susan A.

    The precision and poetic logic of the language used by Anton Chekhov in his plays, particularly "The Sea Gull," can be explored through an analysis of his use of dialogue, characterization, and imagery. Measuring the nature of a relationship, rather than providing a direct literal interchange, the dialogue is both social, when individual…

  7. Factors controlling navigation-channel Shoaling in Laguna Madre, Texas

    USGS Publications Warehouse

    Morton, R.A.; Nava, R.C.; Arhelger, M.

    2001-01-01

    Shoaling in the Gulf Intracoastal Waterway of Laguna Madre, Tex., is caused primarily by recycling of dredged sediments. Sediment recycling, which is controlled by water depth and location with respect to the predominant wind-driven currents, is minimal where dredged material is placed on tidal flats that are either flooded infrequently or where the water is extremely shallow. In contrast, nearly all of the dredged material placed in open water >1.5 m deep is reworked and either transported back into the channel or dispersed into the surrounding lagoon. A sediment flux analysis incorporating geotechnical properties demonstrated that erosion and not postemplacement compaction caused most sediment losses from the placement areas. Comparing sediment properties in the placement areas and natural lagoon indicated that the remaining dredged material is mostly a residual of initial channel construction. Experimental containment designs (shallow subaqueous mound, submerged levee, and emergent levee) constructed in high-maintenance areas to reduce reworking did not retain large volumes of dredged material. The emergent levee provided the greatest retention potential approximately 2 years after construction.

  8. Tidally-forced flow in a rotating, stratified, shoaling basin

    NASA Astrophysics Data System (ADS)

    Winters, Kraig B.

    2015-06-01

    Baroclinic flow of a rotating, stratified fluid in a parabolic basin is computed in response to barotropic tidal forcing using the nonlinear, non-hydrostatic, Boussinesq equations of motion. The tidal forcing is derived from an imposed, boundary-enhanced free-surface deflection that advances cyclonically around a central amphidrome. The tidal forcing perturbs a shallow pycnocline, sloshing it up and down over the shoaling bottom. Nonlinearities in the near-shore internal tide produce an azimuthally independent 'set-up' of the isopycnals that in turn drives an approximately geostrophically balanced, cyclonic, near-shore, sub-surface jet. The sub-surface cyclonic jet is an example of a slowly evolving, nearly balanced flow that is excited and maintained solely by forcing in the fast, super-inertial frequency band. Baroclinic instability of the nearly balanced jet and subsequent interactions between eddies produce a weak transfer of energy back into the inertia-gravity band as swirling motions with super-inertial vorticity stir the stratified fluid and spontaneously emit waves. The sub-surface cyclonic jet is similar in many ways to the poleward flows observed along eastern ocean boundaries, particularly the California Undercurrent. It is conjectured that such currents may be driven by the surface tide rather than by winds and/or along-shore pressure gradients.

  9. Fluid management plan for the Project Shoal Area Offsites Subproject

    SciTech Connect

    1996-08-01

    The US Department of Energy, Nevada Operations Office (DOE/NV) has initiated the Offsites Subproject to characterize the hazards posed to human health and the environment as a result of underground nuclear testing activities at facilities other than the Nevada Test Site (NTS). A primary Subproject objective is to gather adequate data to characterize the various Subproject sites through the collection of surface and subsurface soil samples and by drilling several wells for the collection of groundwater data. The Project Shoal Area (PSA) is one of the Subproject`s Nevada sites and is subject to the requirements set forth in the Federal Facility Compliance Agreement and Consent Order (FFACO) (DOE, 1996a). In accordance with the FFACO, a Corrective Action Investigation Plan (CAIP) has been developed for work at the PSA (designated as Corrective Action Unit Number 416). This Fluid Management Plan (FMP) provides guidance for the management of fluids generated from wells constructed at the PSA. Long-term monitoring and future activities at the site, if required, will be set forth in additional documents as required by the FFACO. The ultimate method for disposition of fluids generated by site operations depends upon sample analysis and process knowledge in relation to fluid management criteria. Section 2 describes well site operations; Section 3 discusses fluid management criteria; Section 4 includes the fluid monitoring program; Section 5 presents the fluid management strategy; Section 6 provides for fluid management during routine well monitoring; and Section 7 contains reporting criteria.

  10. The geomorphology of the Chandeleur Island Wetlands

    SciTech Connect

    Debusschere, K.; Penland, S.; Westphal, K. ); Handley, L. ); Michot, T. ); Reed, D.; Seal, R.

    1990-09-01

    The Chandeleur Islands represent the largest and oldest transgressive barrier island arc in the northern Gulf of Mexico. Generated by the transgressive submergence of the St. Bernard delta complex, the Chandeleur Islands form the protective geologic framework for one of the richest areas of salt marsh and seagrass flats in Louisiana. The Chandeleur barrier island arc is 60 km long and consists of five individual islands backed by a linear, multiple bar system enclosing a shallow basin floored by extensive seagrass flats. The northern part of the Chandeleur chain is the highest in relief, elevation, width, and habitat diversity. Nonstorm morphology is predominantly a combination of continuous dunes and dune terraces. Numerous washover channels and large washover fans extend into the backbarrier environment. Further south, the island width decreases and washover flats and terraces dominate the shoreline morphology In the southernmost section, the island arc is fragmented into a series of small islands and shoals separated by tidal inlets. Between 1984 and 1989, aerial videotape, aerial photographic, and bathymetric surveys were used to map and monitor the geomorphic changes occurring along the shoreline and in backbarrier areas. The aerial videotape mapping surveys focused on the impacts of hurricanes Danny, Elena, and Juan on the geomorphology of the islands. Videotape imagery was acquired in July 1984 and in July (prestorm), August (post-Danny), September (post-Elena), and November (post-Juan) 1985. A coastal geomorphic classification was developed to map the spatial and temporal landscape changes between surveys.

  11. Living on the Edge: Demography of the Slender-Billed Gull in the Western Mediterranean

    PubMed Central

    Sanz-Aguilar, Ana; Tavecchia, Giacomo; Afán, Isabel; Ramírez, Francisco; Doxa, Aggeliki; Bertolero, Albert; Gutiérrez-Expósito, Carlos; Forero, Manuela G.; Oro, Daniel

    2014-01-01

    Small and peripheral populations are typically vulnerable to local extinction processes but important for the metapopulation dynamics of species. The Slender-billed gull (Chroicocephalus genei) is a long-lived species breeding in unstable ephemeral coastal habitats. Their Western Mediterranean populations are relatively small and represent the edge of their global geographical distribution. At a local scale, using long-term data (14 years) on annual breeding success and capture-resights of marked individuals, we estimated and compared the vital rates and evaluated the connectivity of two Spanish populations (Ebro Delta and Doñana) varying in their local environmental conditions. At a metapopulation scale, we analyzed 22 years of data on breeding numbers to predict their future prospects by means of population demographic models. Local survival and breeding success of gulls from the Ebro Delta was lower than those from Doñana, which is likely the result of higher permanent emigration and/or winter mortality in the former. Gulls from the Ebro Delta wintered mostly in Mediterranean areas whereas those from Doñana did so in Atlantic coasts, where food availability is higher. Whereas adult local survival was constant, juvenile local survival showed temporal parallel variations between colonies, probably related to natal dispersal to other breeding colonies. Our results suggested that dispersal was higher at the Ebro Delta and gulls emigrating from their natal colonies settled preferentially in close patches. We found large fluctuations in breeding numbers among local populations probably related to the fact that the Slender-billed gull is a species adapted to unstable and unpredictable habitats with high abilities to disperse between suitable patches depending on environmental stochastic conditions during breeding. PMID:24664115

  12. Distribution patterns predict individual specialization in the diet of dolphin gulls.

    PubMed

    Masello, Juan F; Wikelski, Martin; Voigt, Christian C; Quillfeldt, Petra

    2013-01-01

    Many animals show some degree of individual specialization in foraging strategies and diet. This has profound ecological and evolutionary implications. For example, populations containing diverse individual foraging strategies will respond in different ways to changes in the environment, thus affecting the capacity of the populations to adapt to environmental changes and to diversify. However, patterns of individual specialization have been examined in few species. Likewise it is usually unknown whether specialization is maintained over time, because examining the temporal scale at which specialization occurs can prove difficult in the field. In the present study, we analyzed individual specialization in foraging in Dolphin Gulls Leucophaeus scoresbii, a scavenger endemic to the southernmost coasts of South America. We used GPS position logging and stable isotope analyses (SIA) to investigate individual specialization in feeding strategies and their persistence over time. The analysis of GPS data indicated two major foraging strategies in Dolphin Gulls from New I. (Falkland Is./Islas Malvinas). Tagged individuals repeatedly attended either a site with mussel beds or seabird and seal colonies during 5 to 7 days of tracking. Females foraging at mussel beds were heavier than those foraging at seabird colonies. Nitrogen isotope ratios (δ(15)N) of Dolphin Gull blood cells clustered in two groups, showing that individuals were consistent in their preferred foraging strategies over a period of at least several weeks. The results of the SIA as well as the foraging patterns recorded revealed a high degree of specialization for particular feeding sites and diets by individual Dolphin Gulls. Individual differences in foraging behavior were not related to sex. Specialization in Dolphin Gulls may be favored by the advantages of learning and memorizing optimal feeding locations and behaviors. Specialized individuals may reduce search and handling time and thus, optimize their

  13. Distribution Patterns Predict Individual Specialization in the Diet of Dolphin Gulls

    PubMed Central

    Masello, Juan F.; Wikelski, Martin; Voigt, Christian C.; Quillfeldt, Petra

    2013-01-01

    Many animals show some degree of individual specialization in foraging strategies and diet. This has profound ecological and evolutionary implications. For example, populations containing diverse individual foraging strategies will respond in different ways to changes in the environment, thus affecting the capacity of the populations to adapt to environmental changes and to diversify. However, patterns of individual specialization have been examined in few species. Likewise it is usually unknown whether specialization is maintained over time, because examining the temporal scale at which specialization occurs can prove difficult in the field. In the present study, we analyzed individual specialization in foraging in Dolphin Gulls Leucophaeus scoresbii, a scavenger endemic to the southernmost coasts of South America. We used GPS position logging and stable isotope analyses (SIA) to investigate individual specialization in feeding strategies and their persistence over time. The analysis of GPS data indicated two major foraging strategies in Dolphin Gulls from New I. (Falkland Is./Islas Malvinas). Tagged individuals repeatedly attended either a site with mussel beds or seabird and seal colonies during 5 to 7 days of tracking. Females foraging at mussel beds were heavier than those foraging at seabird colonies. Nitrogen isotope ratios (δ15N) of Dolphin Gull blood cells clustered in two groups, showing that individuals were consistent in their preferred foraging strategies over a period of at least several weeks. The results of the SIA as well as the foraging patterns recorded revealed a high degree of specialization for particular feeding sites and diets by individual Dolphin Gulls. Individual differences in foraging behavior were not related to sex. Specialization in Dolphin Gulls may be favored by the advantages of learning and memorizing optimal feeding locations and behaviors. Specialized individuals may reduce search and handling time and thus, optimize their

  14. Invasive Bighead and Silver Carps Form Different Sized Shoals that Readily Intermix

    PubMed Central

    Ghosal, Ratna; Xiong, Peter X.; Sorensen, Peter W.

    2016-01-01

    Two species of congeneric filter-feeding microphagous carps from Asia, the bighead and the silver carp, were recently introduced to North America and have become highly invasive. These species of carp have similar food habits but the silver carp has the unique habit of jumping when disturbed. Both species have complex but poorly understood social behaviors and while both are thought to aggregate (form groups) and shoal (form tight social groups), this possibility has not yet been examined in these species. The present study examined the grouping tendencies of these species in the laboratory and the effects of fish density and species identity on it. Using nearest neighbor distance (NND) as a metric, we showed that both juvenile bighead and juvenile silver carp grouped (aggregate) strongly (P<0.05) but to different extents, and that fish density had no effect (P>0.05) on this behavior. Within aggregations, bighead carp tended to form a single large shoal while silver carp formed shoals of 2–3 individuals. Further, when tested as mixed-species groups, bighead and silver carp readily shoaled with each other but not with the common carp, which is from Eurasia and a member of another feeding guild. Due to their similar feeding strategies, we speculate that the bighead and silver carp tend to aggregate and shoal to facilitate both their foraging efforts and to avoid predation, while the differences in the size of the shoals they form may seemingly reflect their different anti-predation strategies. These complex shoaling behaviors likely influence Asian carp distribution in rivers, and thus how they might be sampled and managed. PMID:27276024

  15. Can angelfish (Pterophyllum scalare) count? Discrimination between different shoal sizes follows Weber's law.

    PubMed

    Gómez-Laplaza, Luis M; Gerlai, Robert

    2011-01-01

    The ability to discriminate between larger and smaller quantities has been demonstrated in several mammalian and avian species suggesting the possibility of evolutionary conservation of this characteristic. Preference for the larger of two groups has also been shown in fish species, although this ability has rarely been systematically studied in lower order vertebrates, and thus the mechanisms of such ability are not understood. Here, we exploit the tendency of angelfish to seek protection in an unfamiliar environment by joining a group of conspecifics, a behaviour called shoaling. Test fish were given a simultaneous choice between shoals varying both in terms of numerical ratios and absolute numbers of fish. Our results provide evidence for quantity discrimination in angelfish. In general, experimental subjects chose the larger of two shoals. Furthermore, in agreement with Weber's law, which holds that discrimination between two quantities depends on their ratio, the discrimination between shoals of different quantities of fish was more difficult when the shoal sizes became more similar. The limit of discrimination ratio was found to be below 2:1. Briefly, angelfish are able to discriminate between different quantities of conspecifics subject to a ratio limit, a finding that implies a fitness component in this behaviour similar to what has been demonstrated in higher order vertebrates. PMID:20607574

  16. Atlantic Deep-water Response to the Early Pliocene Shoaling of the Central American Seaway

    PubMed Central

    Bell, David B.; Jung, Simon J. A.; Kroon, Dick; Hodell, David A.; Lourens, Lucas J.; Raymo, Maureen E.

    2015-01-01

    The early Pliocene shoaling of the Central American Seaway (CAS), ~4.7–4.2 million years ago (mega annum-Ma), is thought to have strengthened Atlantic Meridional Overturning Circulation (AMOC). The associated increase in northward flux of heat and moisture may have significantly influenced the evolution of Pliocene climate. While some evidence for the predicted increase in North Atlantic Deep Water (NADW) formation exists in the Caribbean and Western Atlantic, similar evidence is missing in the wider Atlantic. Here, we present stable carbon (δ13C) and oxygen (δ18O) isotope records from the Southeast Atlantic-a key region for monitoring the southern extent of NADW. Using these data, together with other δ13C and δ18O records from the Atlantic, we assess the impact of the early Pliocene CAS shoaling phase on deep-water circulation. We find that NADW formation was vigorous prior to 4.7 Ma and showed limited subsequent change. Hence, the overall structure of the deep Atlantic was largely unaffected by the early Pliocene CAS shoaling, corroborating other evidence that indicates larger changes in NADW resulted from earlier and deeper shoaling phases. This finding implies that the early Pliocene shoaling of the CAS had no profound impact on the evolution of climate. PMID:26193070

  17. Atlantic Deep-water Response to the Early Pliocene Shoaling of the Central American Seaway.

    PubMed

    Bell, David B; Jung, Simon J A; Kroon, Dick; Hodell, David A; Lourens, Lucas J; Raymo, Maureen E

    2015-01-01

    The early Pliocene shoaling of the Central American Seaway (CAS), ~4.7-4.2 million years ago (mega annum-Ma), is thought to have strengthened Atlantic Meridional Overturning Circulation (AMOC). The associated increase in northward flux of heat and moisture may have significantly influenced the evolution of Pliocene climate. While some evidence for the predicted increase in North Atlantic Deep Water (NADW) formation exists in the Caribbean and Western Atlantic, similar evidence is missing in the wider Atlantic. Here, we present stable carbon (δ(13)C) and oxygen (δ(18)O) isotope records from the Southeast Atlantic-a key region for monitoring the southern extent of NADW. Using these data, together with other δ(13)C and δ(18)O records from the Atlantic, we assess the impact of the early Pliocene CAS shoaling phase on deep-water circulation. We find that NADW formation was vigorous prior to 4.7 Ma and showed limited subsequent change. Hence, the overall structure of the deep Atlantic was largely unaffected by the early Pliocene CAS shoaling, corroborating other evidence that indicates larger changes in NADW resulted from earlier and deeper shoaling phases. This finding implies that the early Pliocene shoaling of the CAS had no profound impact on the evolution of climate. PMID:26193070

  18. Metals and radionuclides in birds and eggs from Amchitka and Kiska Islands in the Bering Sea/Pacific Ocean ecosystem.

    PubMed

    Burger, Joanna; Gochfeld, Michael

    2007-04-01

    Metals and radionuclide levels in marine birds of the Aleutians are of interest because they are part of subsistence diets of the Aleut people, and can also serve as indicators of marine pollution. We examined geographic and species-specific variations in concentrations of radionuclides in birds and their eggs from Amchitka, the site of underground nuclear tests from 1965 to 1971, and Kiska Islands (a reference site) in the Aleutians, and the levels of lead, mercury and cadmium in eggs. In 2004 we collected common eiders (Somateria mollissima), tufted puffins (Fratercula cirrhata), pigeon guillemot (Cepphus columba) and glaucous-winged gulls (Larus glaucescens) from Amchitka and Kiska, and eggs from eiders and gulls from the two island. We also collected one runt bald eagle (Haliaeetus leucocephalus) chick from both Amchitka and Kiska Islands. For most species, the levels of radionuclide isotopes were below the minimum detectable activity levels (MDA). Out of 74 cesium-137 analyses, only one composite (gulls) was above the MDA, and out of 14 composites tested for plutonium (Pu-239, 240), only one exceeded the MDA (a guillemots). Three composites out of 14 tested had detectable uranium-238. In all cases, the levels were low and close to the MDAs, and were below those reported for other seabirds. There were significant interspecific differences in metal levels in eggs: gulls had significantly higher levels of cadmium and mercury than the eiders, and eiders had higher levels of lead than gulls. There were few significant differences as a function of island, but eiders had significantly higher levels of cadmium in eggs from Kiska, and gulls had significantly higher levels of mercury on Kiska. The levels of cadmium and mercury in eggs of eiders and gulls from this study were above the median for cadmium and mercury from studies in the literature. The levels of mercury in eggs are within the range known to affect avian predators, but seabirds seem less vulnerable to

  19. Abundance and characteristics of the recreational water quality indicator bacteria Escherichia coli and enterococci in gull faeces

    USGS Publications Warehouse

    Fogarty, L.R.; Haack, S.K.; Wolcott, M.J.; Whitman, R.L.

    2003-01-01

    Aims: To evaluate the numbers and selected phenotypic and genotypic characteristics of the faecal indicator bacteria Escherichia coli and enterococci in gull faeces at representative Great Lakes swimming beaches in the United States. Methods and Results: E. coli and enterococci were enumerated in gull faeces by membrane filtration. E. coli genotypes (rep-PCR genomic profiles) and E. coli (Vitek?? GNI+) and enterococci (API?? rapid ID 32 Strep and resistance to streptomycin, gentamicin, vancomycin, tetracycline and ampicillin) phenotypes were determined for isolates obtained from gull faeces both early and late in the swimming season. Identical E. coli genotypes were obtained only from single gull faecal samples but most faecal samples yielded more than one genotype (median of eight genotypes for samples with 10 isolates). E. coli isolates from the same site that clustered at ???85% similarity were from the same sampling date and shared phenotypic characteristics, and at this similarity level there was population overlap between the two geographically isolated beach sites. Enterococcus API?? profiles varied with sampling date. Gull enterococci displayed wide variation in antibiotic resistance patterns, and high-level resistance to some antibiotics. Conclusions: Gull faeces could be a major contributor of E. coli (105-109 CFU g-1) and enterococci (104-108 CFU g-1) to Great Lakes recreational waters. E. coli and enterococci in gull faeces are highly variable with respect to their genotypic and phenotypic characteristics and may exhibit temporal or geographic trends in these features. Significance and Impact of the Study: The high degree of variation in genotypic or phenotypic characteristics of E. coli or enterococci populations within gull hosts will require extensive sampling for adequate characterization, and will influence methods that use these characteristics to determine faecal contamination sources for recreational waters.

  20. Validation Analysis of the Shoal Groundwater Flow and Transport Model

    SciTech Connect

    A. Hassan; J. Chapman

    2008-11-01

    Environmental restoration at the Shoal underground nuclear test is following a process prescribed by a Federal Facility Agreement and Consent Order (FFACO) between the U.S. Department of Energy, the U.S. Department of Defense, and the State of Nevada. Characterization of the site included two stages of well drilling and testing in 1996 and 1999, and development and revision of numerical models of groundwater flow and radionuclide transport. Agreement on a contaminant boundary for the site and a corrective action plan was reached in 2006. Later that same year, three wells were installed for the purposes of model validation and site monitoring. The FFACO prescribes a five-year proof-of-concept period for demonstrating that the site groundwater model is capable of producing meaningful results with an acceptable level of uncertainty. The corrective action plan specifies a rigorous seven step validation process. The accepted groundwater model is evaluated using that process in light of the newly acquired data. The conceptual model of ground water flow for the Project Shoal Area considers groundwater flow through the fractured granite aquifer comprising the Sand Springs Range. Water enters the system by the infiltration of precipitation directly on the surface of the mountain range. Groundwater leaves the granite aquifer by flowing into alluvial deposits in the adjacent basins of Fourmile Flat and Fairview Valley. A groundwater divide is interpreted as coinciding with the western portion of the Sand Springs Range, west of the underground nuclear test, preventing flow from the test into Fourmile Flat. A very low conductivity shear zone east of the nuclear test roughly parallels the divide. The presence of these lateral boundaries, coupled with a regional discharge area to the northeast, is interpreted in the model as causing groundwater from the site to flow in a northeastward direction into Fairview Valley. Steady-state flow conditions are assumed given the absence of

  1. Tributyltin affects shoaling and anxiety behavior in female rare minnow (Gobiocypris rarus).

    PubMed

    Zhang, Jiliang; Zhang, Chunnuan; Sun, Ping; Shao, Xian

    2016-09-01

    Effects of tributyltin (TBT) on reproduction are well established in many fish species. However, few studies report the effects of TBT on non-reproductive behaviors, which is a novel aspect of endocrine disruption in fish. Thus, the present study used rare minnow (Gobiocypris rarus) to investigate the effects of TBT, at environmental concentrations of 1, 10 and 100ng/L, on shoaling and anxiety behaviors. The results showed that fish exposed to TBT had less group cohesion during the course of the 10-min observation period as compared with the control fish. Further, TBT altered the shoaling in the Novel tank test, where shoaling is determined as the tendency to leave a shoal of littermates trapped behind a Plexiglas barrier at one end of the test tank. Fish exposed to TBT had shorter latency before leaving shoal mates and spent more time away from shoal than control fish. In addition, we also used Novel tanks to study the anxiety behavior as the tendency to stay at the bottom when introduced into an unfamiliar environment. The fish exposed to TBT showed increased anxiety, manifested as increased latency to enter the upper half and decreased time in upper half when compared with the control fish. TBT exposure increased the levels of dopamine and its metabolite 3,4-dihydroxyphenylacetic acid, and decreased the levels of 5-hydroxytryptamine and its metabolite 5-hydroxy indole acetic acid in the brain. Thus, the hypofunction of the dopaminergic system or of the serotoninergic system or the combination of the two may underlie the observed behavioral change, which might affect the fitness of fish in their natural environment. PMID:27472783

  2. Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

    SciTech Connect

    K. Pohlmann; G. Pohll; J. Chapman; A. Hassan; R. Carroll; C. Shirley

    2004-03-01

    Groundwater flow and radionuclide transport at the Shoal underground nuclear test are characterized using three-dimensional numerical models, based on site-specific hydrologic data. The objective of this modeling is to provide the flow and transport models needed to develop a contaminant boundary defining the extent of radionuclide-contaminated groundwater at the site throughout 1,000 years at a prescribed level of confidence. This boundary will then be used to manage the Project Shoal Area for the protection of the public and the environment.

  3. Corrective action investigation plan for Project Shoal Area CAU No. 416

    SciTech Connect

    1996-08-01

    This Corrective Action Investigation Plan (CAIP) is part of an ongoing US Department of Energy (DOE)-funded project for the investigation of Corrective Action Unit (CAU) No. 416, Project Shoal Area (PSA). Project Shoal was conducted to determine whether seismic waves produced by underground nuclear testing could be differentiated from naturally occurring earthquakes. The PSA site is located approximately 30 miles southeast of Fallon, Nevada, in the northern portion of Sand Springs Mountains in Churchill County. This CAIP will be implemented in accordance with the Federal Facility Agreement and Consent Order, the Industrial Sites Quality Assurance Project Plan, and all applicable Nevada Division of Environmental Protection policies and regulations.

  4. March 2010 Groundwater Sampling at the Project Shoal Site, Nevada (Data Validation Package)

    SciTech Connect

    2011-03-01

    The U.S. Department of Energy Office of Legacy Management conducted annual sampling at the Project Shoal Area (Shoal) in March 2010. Wells HC-4, HC-5, HC-7, HC-8, MV-1, MV-2 and MV-3 were sampled March 10-12, 2010, as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PLN/S04351, continually updated). Wells HC-1, HC-2, HC-3, and HC-6 were sampled March 24, 2010, by Desert Research Institute personnel.

  5. Anthropogenic input of heavy metals in two Audouin's gull breeding colonies.

    PubMed

    García-Tarrasón, Manuel; Pacho, Sergio; Jover, Lluís; Sanpera, Carolina

    2013-09-15

    Anthropogenic activities have become an important source of heavy metals to the marine environments. Biological sentinels like seabirds' chicks have been widely used to monitorize the levels of some heavy metals. Due to its mainly marine foraging habits, Audouin's gull fits well for this purpose. Mercury and lead levels were measured in mantle feathers of Audouin's gull chicks from two colonies in NE Iberian Peninsula: the Ebro Delta and the Llobregat Delta. Both are anthropized areas subject to differential pollutant inputs. Lead levels were significantly higher in the Llobregat Delta probably due to the use of leaded fuel in the nearby Barcelona airport. On the other side, mercury concentrations were higher in the Ebro Delta, in relation with the disposal of the toxic sediments at the Flix site carried down by the Ebro River. These mercury levels in the Ebro chicks reached values that have been described as toxic. PMID:23871579

  6. Stable isotope analysis of temporal variation in the diets of pre-fledged Laughing Gulls

    USGS Publications Warehouse

    Knoff, A.J.; Macko, S.A.; Erwin, R.M.; Brown, K.M.

    2002-01-01

    The *13C, *15N, and *34S stable isotopic values of feathers from pre-fledged Laughing Gulls (Larus atricilla) in coastal Virginia and Jamaica Bay, New York were used to examine dietary variation during the nestling period. The tip portions of the feathers were used to indicate diet during the initiation of primary feather growth, whereas the base portions indicated diet during the period immediately prior to fledging. The results indicate that diets of the nestlings in Virginia moved to a higher trophic level during the period prior to fledging, however the New York nestlings did not appear to undergo any appreciable dietary change during this period. Overall, nestlings from both colonies consumed proportionately more foods of marine origin than freshwater or terrestrial. Therefore, the results do not support those of earlier studies that suggested that partially developed salt glands in young gulls might restrict the diet to more terrestrial or freshwater prey in the early stages of nestling growth.

  7. California gull chicks raised near colony edges have elevated stress levels

    USGS Publications Warehouse

    Herring, Garth; Ackerman, Joshua T.

    2011-01-01

    Coloniality in nesting birds represents an important life history strategy for maximizing reproductive success. Birds nesting near the edge of colonies tend to have lower reproductive success than individuals nesting near colony centers, and offspring of edge-nesting parents may be impaired relative to those of central-nesting parents. We used fecal corticosterone metabolites in California gull chicks (Larus californicus) to examine whether colony size or location within the colony influenced a chick's physiological condition. We found that chicks being raised near colony edges had higher fecal corticosterone metabolite concentrations than chicks raised near colony centers, but that colony size (ranging from 150 to 11,554 nests) had no influence on fecal corticosterone levels. Fecal corticosterone metabolite concentrations also increased with chick age. Our results suggest that similarly aged California gull chicks raised near colony edges may be more physiologically stressed, as indicated by corticosterone metabolites, than chicks raised near colony centers.

  8. Anatomy of a shoreface sand ridge revisited using foraminifera: False Cape Shoals, Virginia/North Carolina inner shelf

    USGS Publications Warehouse

    Robinson, M.M.; McBride, R.A.

    2008-01-01

    Certain details regarding the origin and evolution of shelf sand ridges remain elusive. Knowledge of their internal stratigraphy and microfossil distribution is necessary to define the origin and to determine the processes that modify sand ridges. Fourteen vibracores from False Cape Shoal A, a well-developed shoreface-attached sand ridge on the Virginia/North Carolina inner continental shelf, were examined to document the internal stratigraphy and benthic foraminiferal assemblages, as well as to reconstruct the depositional environments recorded in down-core sediments. Seven sedimentary and foraminiferal facies correspond to the following stratigraphic units: fossiliferous silt, barren sand, clay to sandy clay, laminated and bioturbated sand, poorly sorted massive sand, fine clean sand, and poorly sorted clay to gravel. The units represent a Pleistocene estuary and shoreface, a Holocene estuary, ebb tidal delta, modern shelf, modern shoreface, and swale fill, respectively. The succession of depositional environments reflects a Pleistocene sea-level highstand and subsequent regression followed by the Holocene transgression in which barrier island/spit systems formed along the Virginia/North Carolina inner shelf ???5.2 ka and migrated landward and an ebb tidal delta that was deposited, reworked, and covered by shelf sand.

  9. Anatomy of a shoreface sand ridge revisted using foraminifera: False Cape Shoals, Virginia/North Carolina inner shelf

    USGS Publications Warehouse

    Robinson, Marci M.; McBride, Randolph A.

    2008-01-01

    Certain details regarding the origin and evolution of shelf sand ridges remain elusive. Knowledge of their internal stratigraphy and microfossil distribution is necessary to define the origin and to determine the processes that modify sand ridges. Fourteen vibracores from False Cape Shoal A, a well-developed shoreface-attached sand ridge on the Virginia/North Carolina inner continental shelf, were examined to document the internal stratigraphy and benthic foraminiferal assemblages, as well as to reconstruct the depositional environments recorded in down-core sediments. Seven sedimentary and foraminiferal facies correspond to the following stratigraphic units: fossiliferous silt, barren sand, clay to sandy clay, laminated and bioturbated sand, poorly sorted massive sand, fine clean sand, and poorly sorted clay to gravel. The units represent a Pleistocene estuary and shoreface, a Holocene estuary, ebb tidal delta, modern shelf, modern shoreface, and swale fill, respectively. The succession of depositional environments reflects a Pleistocene sea-level highstand and subsequent regression followed by the Holocene transgression in which barrier island/spit systems formed along the Virginia/North Carolina inner shelf not, vert, ~5.2 ka and migrated landward and an ebb tidal delta that was deposited, reworked, and covered by shelf sand.

  10. Evaluating gull diets: A comparison of conventional methods and stable isotope analysis

    USGS Publications Warehouse

    Weiser, E.L.; Powell, A.N.

    2011-01-01

    Samples such as regurgitated pellets and food remains have traditionally been used in studies of bird diets, but these can produce biased estimates depending on the digestibility of different foods. Stable isotope analysis has been developed as a method for assessing bird diets that is not biased by digestibility. These two methods may provide complementary or conflicting information on diets of birds, but are rarely compared directly. We analyzed carbon and nitrogen stable isotope ratios of feathers of Glaucous Gull (Larus hyperboreus) chicks from eight breeding colonies in northern Alaska, and used a Bayesian mixing model to generate a probability distribution for the contribution of each food group to diets. We compared these model results with probability distributions from conventional diet samples (pellets and food remains) from the same colonies and time periods. Relative to the stable isotope estimates, conventional analysis often overestimated the contributions of birds and small mammals to gull diets and often underestimated the contributions of fish and zooplankton. Both methods gave similar estimates for the contributions of scavenged caribou, miscellaneous marine foods, and garbage to diets. Pellets and food remains therefore may be useful for assessing the importance of garbage relative to certain other foods in diets of gulls and similar birds, but are clearly inappropriate for estimating the potential impact of gulls on birds, small mammals, or fish. However, conventional samples provide more species-level information than stable isotope analysis, so a combined approach would be most useful for diet analysis and assessing a predator's impact on particular prey groups. ?? 2011 Association of Field Ornithologists.

  11. Rapidly increasing methyl mercury in endangered ivory gull (Pagophila eburnea) feathers over a 130 year record

    PubMed Central

    Bond, Alexander L.; Hobson, Keith A.; Branfireun, Brian A.

    2015-01-01

    Mercury (Hg) is increasing in marine food webs, especially at high latitudes. The bioaccumulation and biomagnification of methyl mercury (MeHg) has serious effects on wildlife, and is most evident in apex predators. The MeHg body burden in birds is the balance of ingestion and excretion, and MeHg in feathers is an effective indicator of overall MeHg burden. Ivory gulls (Pagophila eburnea), which consume ice-associated prey and scavenge marine mammal carcasses, have the highest egg Hg concentrations of any Arctic bird, and the species has declined by more than 80% since the 1980s in Canada. We used feathers from museum specimens from the Canadian Arctic and western Greenland to assess whether exposure to MeHg by ivory gulls increased from 1877 to 2007. Based on constant feather stable-isotope (δ13C, δ15N) values, there was no significant change in ivory gulls' diet over this period, but feather MeHg concentrations increased 45× (from 0.09 to 4.11 µg g−1 in adults). This dramatic change in the absence of a dietary shift is clear evidence of the impact of anthropogenic Hg on this high-latitude threatened species. Bioavailable Hg is expected to increase in the Arctic, raising concern for continued population declines in high-latitude species that are far from sources of environmental contaminants. PMID:25788594

  12. Adrenocortical function of Arctic-breeding glaucous gulls in relation to persistent organic pollutants.

    PubMed

    Verboven, Nanette; Verreault, Jonathan; Letcher, Robert J; Gabrielsen, Geir W; Evans, Neil P

    2010-03-01

    Unpredictable changes in the environment stimulate the avian hypothalamo-pituitary-adrenal axis to produce corticosterone, which induces behavioural and metabolic changes that enhance survival in the face of adverse environmental conditions. In addition to profound environmental perturbations, such as severe weather conditions and unpredictable food shortages, many Arctic-breeding birds are also confronted with chronic exposure to persistent organic pollutants (POPs), some of which are known to disrupt endocrine processes. This study investigated the adrenocortical function of a top predator in the Arctic marine environment, the glaucous gull (Larus hyperboreus). High concentrations of organochlorines, brominated flame retardants and metabolically-derived products in blood plasma of incubating glaucous gulls were associated with high baseline corticosterone concentrations in both sexes and a reduced stress response in males. Contaminant-related changes in corticosterone concentration occurred over and above differences in body condition and seasonal variation. Chronically high corticosterone concentrations and/or a compromised adrenocortical response to stress can have negative effects on the health of an individual. The results of the present study suggest that exposure to POPs may increase the vulnerability of glaucous gulls to environmental stressors and thus could potentially compromise their ability to adapt to the rapidly changing environmental conditions associated with climate change that are currently seen in the Arctic. PMID:19932109

  13. Antibiotic resistance patterns in Escherichia coli from gulls in nine European countries

    PubMed Central

    Stedt, Johan; Bonnedahl, Jonas; Hernandez, Jorge; McMahon, Barry J.; Hasan, Badrul; Olsen, Björn; Drobni, Mirva; Waldenström, Jonas

    2014-01-01

    Background The prevalence of antibiotic resistant faecal indicator bacteria from humans and food production animals has increased over the last decades. In Europe, resistance levels in Escherichia coli from these sources show a south-to-north gradient, with more widespread resistance in the Mediterranean region compared to northern Europe. Recent studies show that resistance levels can be high also in wildlife, but it is unknown to what extent resistance levels in nature conform to the patterns observed in human-associated bacteria. Methods To test this, we collected 3,158 faecal samples from breeding gulls (Larus sp.) from nine European countries and tested 2,210 randomly isolated E. coli for resistance against 10 antibiotics commonly used in human and veterinary medicine. Results Overall, 31.5% of the gull E. coli isolates were resistant to ≥1 antibiotic, but with considerable variation between countries: highest levels of isolates resistant to ≥1 antibiotic were observed in Spain (61.2%) and lowest levels in Denmark (8.3%). For each tested antibiotic, the Iberian countries were either the countries with the highest levels or in the upper range in between-country comparisons, while northern countries generally had a lower proportion of resistant E. coli isolates, thereby resembling the gradient of resistance seen in human and food animal sources. Conclusion We propose that gulls may serve as a sentinel of environmental levels of antibiotic resistant E. coli to complement studies of human-associated microbiota. PMID:24427451

  14. The effects of testosterone manipulation on the body condition of captive male yellow-legged gulls.

    PubMed

    Alonso-Alvarez, Carlos; Ferrer, Miguel; Figuerola, Jordi; Veira, José A R; Estepa, Julio; Torres, Luis M

    2002-02-01

    Persistently high testosterone levels are believed to be costly to males due to their negative effect on body condition. However, this assumption could not be validated when we analysed birds isolated from all social interactions. The hypothesis was tested on birds kept in isolation in order to analyse the effects of testosterone per se, and thereby exclude the influence of social interactions. Adult male yellow-legged gulls (Larus cachinnans) were captured, and after a period of adjustment, some individuals were subcutaneously implanted with testosterone, while the rest were used as controls. The gulls received ad libitum food for 10 days and were then fasted for 4 days. Thyroid hormones, body-mass change, daily food intake, hematocrit and several plasma biochemical parameters were analysed. Treated (T)-males maintained constant levels of plasma total protein throughout the experiment, whilst control (C)-males showed a decrease. We did not find any other differences between groups for the other variables analysed. Since the implanted birds sustained high testosterone levels for a number of days, any cost to body condition would have been revealed if these costs levels were actually important. Our results do not support the hypothesis that a reduction in body condition can be directly produced by plasma testosterone, although total protein changes do suggest different anabolic patterns in testosterone-treated gulls. PMID:11818219

  15. Relationships of metals between feathers and diets of black-tailed gull (Larus crassirostris) chicks.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2014-03-01

    In birds, metal contaminants in feathers are influenced by prey concentrations and environmental quality. In Black-tailed Gull chicks, Cd, Pb and Cu concentrations were strongly correlated between feathers and stomach contents. Between feathers and livers, Pb, Zn and Fe concentrations were significantly correlated. Cd concentrations were within the range of other seabirds and within the background level for bird feathers (<2 μg/g dw). At the lighthouse, eight chicks exceeded the background for Pb level in feathers (>4 μg/g dw). Elevated Pb concentrations might be attributed to ingestion of paint-based chips and natural (soil and rocks) sources. There is evidence that the analyzed birds suffered from acute toxicity, including high levels of pecking from conspecifics and increased mortality from elevated Pb levels. It seems likely that these birds might experience negative health effects from this increased Pb exposure. As a result, Black-tailed Gull chick feathers are a very useful monitoring tool for assessing Cd, Pb and Cu contamination. Essential elements such as Fe, Zn, Mn and Cu were all within the acceptable range of normal concentrations for seabird species including gulls and may be maintained by normal homeostatic mechanisms. PMID:24414165

  16. Dioxins and dl-PCBs in gull eggs from Spanish Natural Parks (2010-2013).

    PubMed

    Morales, Laura; Gene'rosa Martrat, Ma; Parera, Jordi; Bertolero, Albert; Ábalos, Manuela; Santos, Francisco Javier; Lacorte, Silvia; Abad, Esteban

    2016-04-15

    The aim of this study was to evaluate the presence and distribution of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and biphenyls (PCBs), concretely those so-called as dioxin-like PCBs, in yellow-legged gull eggs (Larus michahellis) collected from five Natural Parks (some of them National Parks) in Spain during the period 2010-2013. PCDD/Fs and dl-PCBs were detected in all the samples. Due to the proximity to important urban and industrial areas higher concentrations were determined in colonies located in the Northern Mediterranean coast than those found in the Southern Mediterranean or Atlantic colonies where a softer anthropogenic impact occurs. Mean ∑PCDD/F concentrations ranged from 49 to 223pg/g lipid weight (lw) and ∑dl-PCB concentrations varied from 146 to 911ng/g lw. In the Natural Park of the Ebro Delta (Northern Mediterranean coast) two gull species share habitat: yellow-legged and Audouin gull (Larus audouinii). Eggs from both species were collected and PCDD/F and dl-PCB levels compared. The species that feeds exclusively on pelagic fish (L. audouinii) had significantly higher PCDD/F and dl-PCB levels than the scavenger L. michahellis, pointing out the diet-dependent differences in the accumulation of persistent organic pollutants between similar cohabitant breeding species. Finally, mean TEQ values were in general below those considered as critical for toxicological effects in birds. PMID:26808402

  17. Rapidly increasing methyl mercury in endangered ivory gull (Pagophila eburnea) feathers over a 130 year record.

    PubMed

    Bond, Alexander L; Hobson, Keith A; Branfireun, Brian A

    2015-04-22

    Mercury (Hg) is increasing in marine food webs, especially at high latitudes. The bioaccumulation and biomagnification of methyl mercury (MeHg) has serious effects on wildlife, and is most evident in apex predators. The MeHg body burden in birds is the balance of ingestion and excretion, and MeHg in feathers is an effective indicator of overall MeHg burden. Ivory gulls (Pagophila eburnea), which consume ice-associated prey and scavenge marine mammal carcasses, have the highest egg Hg concentrations of any Arctic bird, and the species has declined by more than 80% since the 1980s in Canada. We used feathers from museum specimens from the Canadian Arctic and western Greenland to assess whether exposure to MeHg by ivory gulls increased from 1877 to 2007. Based on constant feather stable-isotope (δ(13)C, δ(15)N) values, there was no significant change in ivory gulls' diet over this period, but feather MeHg concentrations increased 45× (from 0.09 to 4.11 µg g(-1) in adults). This dramatic change in the absence of a dietary shift is clear evidence of the impact of anthropogenic Hg on this high-latitude threatened species. Bioavailable Hg is expected to increase in the Arctic, raising concern for continued population declines in high-latitude species that are far from sources of environmental contaminants. PMID:25788594

  18. A method for resolving occlusions when multitracking individuals in a shoal.

    PubMed

    Dolado, Ruth; Gimeno, Elisabet; Beltran, Francesc S; Quera, Vicenç; Pertusa, José F

    2015-12-01

    Studying the collective behavior of fishes often requires tracking a great number of individuals. When many fishes move together, it is common for individuals to move so close to each other that some fishes superimpose themselves on others during one or several units of time, which impacts on tracking accuracy (i.e., loss of fish trajectories, interchange of fish identities). Type 1 occlusions arise when two fishes swim so near each other that they look like one long fish, whereas type 2 occlusions occur when the fishes' trajectories cross to create a T- or X-shaped individual. We propose an image processing method for resolving these types of occlusions when multitracking shoals in two dimensions. We assessed processing effectiveness after videorecording shoals of 20 and 40 individuals of two species that exhibit different shoal styles: zebrafish (Danio rerio) and black neon tetras (Hyphessobrycon herbertaxelrodi). Results show that, although the number of occlusions depended on both the number of individuals and the species, the method is able to effectively resolve a great deal of occlusions, irrespective of the species and the number of individuals. It also produces images that can be used in a multitracking system to detect individual fish trajectories. Compared to other methods, our approach makes it possible to study shoals with water depths similar to those seen in the natural conditions of the two species studied. PMID:25294043

  19. Tidal characteristics in the Wenzhou offshore waters and changes resulting from the Wenzhou Shoal Reclamation Project

    NASA Astrophysics Data System (ADS)

    Bao, Min; Bao, Xianwen; Yu, Huaming; Ding, Yang

    2015-12-01

    The Wenzhou Shoal Reclamation Project is the core part of Wenzhou Peninsula Engineering which is a big comprehensive development project to expand the city space. The dynamics of the surrounding area was proved to suffer little effect in response to the Lingni north dyke since it was built approximately along the current direction. Therefore, this paper focuses firstly on the tidal characteristics in the Wenzhou and Yueqing bays with the Lingni north dyke being built and then on the changes resulting from the implementation of the on-going Wenzhou Shoal Reclamation Project (WSRP) which will reclaim land from the whole Wenzhou Shoal. To simulate the tidal dynamics, a high-resolution coastal ocean model with unstructured triangular grids was set up for the Wenzhou and Yueqing Bays. The model resolved the complicated tidal dynamics with the simulated tidal elevation and current in good agreement with observations. In the study area, M2 is the predominant tidal component, which means the tide is semidiurnal. The new reclamation project hardly affects the Yueqing Bay and the open ocean, but there are concentrated effects on the mouth of the southern branch of the Oujiang River and the southwest of Wenzhou Shoal. This study provides an indicative reference to the local government and helps to weigh the advantages and disadvantages of the project.

  20. Evaluation of groundwater flow and transport at the Shoal underground nuclear test: An interim report

    SciTech Connect

    Pohll, G.; Chapman, J.; Hassan, A.; Papelis, C.; Andricevic, R.; Shirley, C.

    1998-07-01

    Since 1962, all United States nuclear tests have been conducted underground. A consequence of this testing has been the deposition of large amounts of radioactive materials in the subsurface, sometimes in direct contact with groundwater. The majority of this testing occurred on the Nevada Test Site, but a limited number of experiments were conducted in other locations. One of these is the subject of this report, the Project Shoal Area (PSA), located about 50 km southeast of Fallon, Nevada. The Shoal test consisted of a 12-kiloton-yield nuclear detonation which occurred on October 26, 1963. Project Shoal was part of studies to enhance seismic detection of underground nuclear tests, in particular, in active earthquake areas. Characterization of groundwater contamination at the Project Shoal Area is being conducted by the US Department of Energy (DOE) under the Federal Facility Agreement and Consent Order (FFACO) with the State of Nevada Department of Environmental Protection and the US Department of Defense (DOD). This order prescribes a Corrective Action Strategy (Appendix VI), which, as applied to underground nuclear tests, involves preparing a Corrective Action Investigation Plan (CAIP), Corrective Action Decision Document (CADD), Corrective Action Plan, and Closure Report. The scope of the CAIP is flow and transport modeling to establish contaminant boundaries that are protective of human health and the environment. This interim report describes the current status of the flow and transport modeling for the PSA.

  1. Long-term Monitoring Plan for the Shoal Underground Nuclear Test

    SciTech Connect

    Ahmed Hassan

    2005-02-01

    The flow and transport model of Shoal is used to design a three-well monitoring network to be part of the long-term monitoring network for the site and achieve two objectives: (1) detect the presence of radionuclides in case they migrate to the monitoring well locations, and (2) provide field data to compare with model predictions as part of the model validation process. Using three different quantitative approaches and the numerical groundwater flow and transport model developed for Shoal, three new monitoring well locations were identified from 176 different networks. In addition to the quantitative analyses using the numerical model, the development of the monitoring network for Shoal will also be subject to qualitative hydrogeologic interpretation during implementation. information will only be available during the fieldwork, it will be incorporated in the monitoring well design at the time of well installation. Finally, it should be noted that the CADD-CAP for Shoal, including the compliance boundary, is not yet approved. Should the compliance boundary change from the 1,000-year MCL contaminant boundary, well locations may also need to change. However, the analysis reported here provides a number of alternatives with reasonable detection efficiency.

  2. THE ARGO MERCHANT OIL SPILL AND THE SEDIMENTS OF NANTUCKET SHOALS: RESEARCH, LITIGATION AND LEGISLATION

    EPA Science Inventory

    On December 15, 1976, the tanker Argo Merchant ran around on Fishing Rip of Nantucket Shoals off the coast of Massachusetts. After several days of stormy weather she broke apart releasing her entire cargo of 28 X 10 to 3rd power metric tons of No. 6 fuel oil into the ocean. Feder...

  3. A COMPARISON OF ARGO MERCHANT OIL AND SEDIMENT HYDROCARBONS FROM NANTUCKET SHOALS

    EPA Science Inventory

    Surface sediment samples collected from the Nantucket Shoals Argo Merchant wreck site area in February, 1977, were analyzed for hydrocarbon content by gas chromatography. Analysis of sediment grab subsections revealed no clear trend of hydrocarbon contamination as a function of d...

  4. Spontaneous discrimination of small quantities: shoaling preferences in angelfish (Pterophyllum scalare).

    PubMed

    Gómez-Laplaza, Luis M; Gerlai, Robert

    2011-07-01

    The ability to quantify, i.e. to estimate quantity, may provide evolutionary advantages in some contexts and has been demonstrated in a variety of animal species. In a prior study, we showed that angelfish (Pterophyllum scalare) were able to discriminate between groups (shoals) in which a large number of conspecifics swam preferring to join the larger of the two. Our results implied that angelfish can compare relative shoal sizes likely on the basis of some quantitative attributes of the shoal. Here, also using a binary preference test, we examined whether angelfish are able to discriminate between shoals of small numbers of conspecifics, and if so whether their performance reveals a comparable underlying mechanism to that proposed for discrimination of small quantities in human and non-human animals, namely the possible precursor of the ability to count. Our results demonstrate that fish reliably chose 4 versus 1, 3 versus 1, 2 versus 1 and 3 versus 2 individuals, but were at chance performance level when having to choose between 4 versus 3, 5 versus 4 and 6 versus 5. Findings also reveal that the density of the fish in the stimulus shoals did not significantly affect the performance of experimental angelfish. These results are compatible with the hypothesis of the existence of an object-file mechanism to discriminate small quantities in vertebrates and provide evidence for spontaneous discrimination of up to three elements in angelfish, a similar limit to that found in human and non-human animals. The findings add to the growing body of data, suggesting that the mechanisms underlying discrimination between different quantities of items may be shared across different taxa and have an evolutionary ancient origin. PMID:21409443

  5. Environmental pollutants in endangered vs. increasing subspecies of the lesser black-backed gull on the Norwegian Coast.

    PubMed

    Bustnes, Jan Ove; Helberg, Morten; Strann, Karl-Birger; Skaare, Janneche Utne

    2006-12-01

    Organochlorine (OC) residues were measured in eggs and blood of different subspecies of the lesser black-backed gull, Larus fuscus, on the Norwegian coast: a) increasing L. f. intermedius in the North Sea; b) endangered L. f. fuscus near the Arctic Circle; c) L. f. fuscus and greyish-mantled gulls, with a L. f. intermedius appearance, in the Barents Sea region. The dominating OCs in lesser black-backed gulls were polychlorinated biphenyls (PCB) and p,p'-dichlorodiphenyldichloroethylene (DDE). DDE and beta-hexachlorocyclohexane (beta-HCH) residues were higher in L. f. fuscus compared to L. f. intermedius and greyish-mantled birds in the Barents Sea region. In the latter area, blood residues of PCB and DDE in lesser black-backed gulls were as high as in great black-backed gulls, Larus marinus, while in the other regions they were lower. The higher DDE residues in endangered L. f. fuscus compared to increasing L. f. intermedius and greyish-mantled birds, which are invading northern Norway, suggest that OCs may have played a role in the population decline of L. f. fuscus, possibly in combination with nutrient stress. PMID:16564607

  6. Diets of nesting laughing gulls (Larus atricilla) at the Virginia Coast Reserve: observations from stable isotope analysis

    USGS Publications Warehouse

    Knoff, A.J.; Macko, S.A.; Erwin, R.M.

    2001-01-01

    Food web studies often ignore details of temporal, spatial, and intrapopulation dietary variation in top-level consumers. In this study, intrapopulation dietary variation of a dominant carnivore, the Laughing Gull (Larus atricilla), was examined using carbon, nitrogen, and sulfur isotope analysis of gull tissues as well as their prey (fish, invertebrates, and insects) from the Virginia Coast Reserve estuarine system. As earlier traditional diet studies found evidence of individual dietary specialization within gull populations, this study used stable isotope analysis to assess specialization in a coastal Laughing Gull population. Specifically, blood, muscle, and feather isotope values indicated significant intrapopulation dietary specialization. Some gulls relied more heavily on estuarine prey (mean blood δ13C = -17.5, δ15N = 12.6, and δ34S = 9.3), whereas others appeared to consume more foods of marine origin (mean blood δ13C = -19.4, δ15N = 14.8, and δ34S = 10.4). It is important to account for such dietary variability when assessing trophic linkages in dynamic estuarine systems.

  7. Salmonella enterica resistant to antimicrobials in wastewater effluents and black-headed gulls in the Czech Republic, 2012.

    PubMed

    Masarikova, Martina; Manga, Ivan; Cizek, Alois; Dolejska, Monika; Oravcova, Veronika; Myskova, Petra; Karpiskova, Renata; Literak, Ivan

    2016-01-15

    We investigated the presence and epidemiological relatedness of Salmonella isolates from a wastewater treatment plant (WWTP) in Brno, Czech Republic and from nestlings of black-headed gulls (Chroicocephalus ridibundus) at the Nove Mlyny waterworks, situated 35 km downstream from the WWTP. During 2012, we collected 37 wastewater samples and 284 gull cloacal swabs. From wastewater samples, we obtained 89 Salmonella isolates belonging to 19 serotypes. At least one resistant strain was contained in 89% of those samples. Ten different serotypes of Salmonella were detected in 38 young gulls, among which 14 (37%) were resistant to antimicrobials. Wastewater isolates were mostly resistant to sulphonamides and tetracycline, gull isolates to tetracycline and ampicillin. We detected the occurrence of blaTEM-1,tet(A), tet(B), tet(G), sul1, sul2, sul3, floR and strA resistance genes. For the first time, we identified a class 1 integron with the dfrA12-orfF-aadA2 gene cassette in S. Infantis. Using pulsed-field gel electrophoresis, we confirmed the presence of identical clusters of S. Agona, S. Enteritidis PT8, S. Infantis and S. Senftenberg in wastewater and black-headed gulls, thus indicating the possibility of resistant Salmonella isolates spreading over long distances in the environment. PMID:26519571

  8. Diets of nesting laughing gulls (Larus atricilla) at the Virginia Coast Reserve: observations from stable isotope analysis.

    PubMed

    Knoff, A J; Macko, S A; Erwin, R M

    2001-01-01

    Food web studies often ignore details of temporal, spatial, and intrapopulation dietary variation in top-level consumers. In this study, intrapopulation dietary variation of a dominant carnivore, the Laughing Gull (Larus atricilla), was examined using carbon, nitrogen, and sulfur isotope analysis of gull tissues as well as their prey (fish, invertebrates, and insects) from the Virginia Coast Reserve estuarine system. As earlier traditional diet studies found evidence of individual dietary specialization within gull populations, this study used stable isotope analysis to assess specialization in a coastal Laughing Gull population. Specifically, blood, muscle, and feather isotope values indicated significant intrapopulation dietary specialization. Some gulls relied more heavily on estuarine prey (mean blood delta13C = -17.5, delta15N = 12.6, and delta34S = 9.3), whereas others appeared to consume more foods of marine origin (mean blood delta13C = -19.4, delta15N = 14.8, and delta34S = 10.4). It is important to account for such dietary variability when assessing trophic linkages in dynamic estuarine systems. PMID:11558657

  9. Molecular epidemiology of Salmonella spp. isolates from gulls, fish-meal factories, feed factories, animals and humans in Norway based on pulsed-field gel electrophoresis.

    PubMed Central

    Nesse, L. L.; Refsum, T.; Heir, E.; Nordby, K.; Vardund, T.; Holstad, G.

    2005-01-01

    The molecular epidemiology of 98 isolates of Salmonella serovar Agona (n = 27), S. Montevideo (n = 42) and S. Senftenberg (n = 29) from wild-living gulls, fish-meal factories, feed factories, humans and domestic animals was investigated using pulsed-field gel electrophoresis (PFGE) and computerized numerical analysis. Two of the S. Agona profiles were identified both in gulls and in two of the factories. In addition, one of these profiles was detected in two infected poultry farms. Two of the S. Montevideo profiles were also identified both in gulls and in two of the factories, and one of these profiles was observed in a human isolate. Four factories shared an identical S. Senftenberg profile. The S. Senftenberg profile found in gulls was not identified in any other source investigated. The presence of isolates with identical PFGE profiles indicates potential epidemiological links between different factories, as well as between gulls and factories. PMID:15724711

  10. How islands stir and fertilize the upper ocean

    NASA Astrophysics Data System (ADS)

    Hasegawa, D.; Yamazaki, H.; Lueck, R. G.; Seuront, L.

    2004-08-01

    Large differences between the upstream and lee side flow characteristics of an isolated island in the Kuroshio have been identified from a three-dimensional velocity survey and from vertical profiles of fine- and micro-structure. In the island wake, the relative vorticity is O(10f), the horizontal current divergence indicates upwelling of O(0.01 m s-1), and the rate of dissipation of kinetic energy is O(10-4 W kg-1). Isopycnal surfaces shoal by 60 m on the lee side and surface nitrate concentration increases seven-fold. Flow blockage by the island and the Izu-Ogasawara Ridge on its flanks, induces horizontal and vertical flow separation. The associated lateral and vertical shear drive the upwelling and the vertical mixing in the wake and produces a very pronounced ``island mass effect.''

  11. Monitoring organic contaminants in eggs of glaucous and glaucous-winged gulls (Larus hyperboreus and Larus glaucescens) from Alaska.

    PubMed

    Vander Pol, Stacy S; Becker, Paul R; Ellisor, Michael B; Moors, Amanda J; Pugh, Rebecca S; Roseneau, David G

    2009-03-01

    Gull eggs have been used to monitor contaminants in many parts of the world. The Seabird Tissue Archival and Monitoring Project (STAMP) is a long-term program designed to track trends in pollutants in northern marine environments using seabird eggs. Glaucous and glaucous-winged gull (Larus hyperboreus and Larus glaucescens) eggs collected in 2005 from seven Alaskan colonies were analyzed for organic contaminants. Concentrations ranged from below detection limits to 322 ng g(-1) wet mass in one egg for 4,4'-DDE and differed among the samples collected in the Gulf of Alaska and Bering and Chukchi Seas. Chick growth and survival rates may be affected by the contaminant levels found in the eggs, but the eggs should be safe for human consumption if they are eaten in small quantities. STAMP plans to continue collecting and banking gull eggs for future real-time and retrospective analyses. PMID:19110348

  12. Satellite Tracking on the Flyways of Brown-Headed Gulls and Their Potential Role in the Spread of Highly Pathogenic Avian Influenza H5N1 Virus

    PubMed Central

    Ratanakorn, Parntep; Wiratsudakul, Anuwat; Wiriyarat, Witthawat; Eiamampai, Krairat; Farmer, Adrian H.; Webster, Robert G.; Chaichoune, Kridsada; Suwanpakdee, Sarin; Pothieng, Duangrat; Puthavathana, Pilaipan

    2012-01-01

    Brown-headed gulls (Larus brunnicephalus), winter visitors of Thailand, were tracked by satellite telemetry during 2008–2011 for investigating their roles in the highly pathogenic avian influenza (HPAI) H5N1 virus spread. Eight gulls negative for influenza virus infection were marked with solar-powered satellite platform transmitters at Bang Poo study site in Samut Prakarn province, Thailand; their movements were monitored by the Argos satellite tracking system, and locations were mapped. Five gulls completed their migratory cycles, which spanned 7 countries (China, Bangladesh, India, Myanmar, Thailand, Cambodia, and Vietnam) affected by the HPAI H5N1 virus. Gulls migrated from their breeding grounds in China to stay overwinter in Thailand and Cambodia; while Bangladesh, India, Myanmar, and Vietnam were the places of stopovers during migration. Gulls traveled an average distance of about 2400 km between Thailand and China and spent 1–2 weeks on migration. Although AI surveillance among gulls was conducted at the study site, no AI virus was isolated and no H5N1 viral genome or specific antibody was detected in the 75 gulls tested, but 6.6% of blood samples were positive for pan-influenza A antibody. No AI outbreaks were reported in areas along flyways of gulls in Thailand during the study period. Distance and duration of migration, tolerability of the captive gulls to survive the HPAI H5N1 virus challenge and days at viral shedding after the virus challenging suggested that the Brown-headed gull could be a potential species for AI spread, especially among Southeast Asian countries, the epicenter of H5N1 AI outbreak. PMID:23209623

  13. Genetic markers for rapid PCR-based identification of gull, Canada goose, duck, and chicken fecal contamination in water.

    PubMed

    Green, Hyatt C; Dick, Linda K; Gilpin, Brent; Samadpour, Mansour; Field, Katharine G

    2012-01-01

    Avian feces contaminate waterways but contribute fewer human pathogens than human sources. Rapid identification and quantification of avian contamination would therefore be useful to prevent overestimation of human health risk. We used subtractive hybridization of PCR-amplified gull fecal 16S RNA genes to identify avian-specific fecal rRNA gene sequences. The subtracters were rRNA genes amplified from human, dog, cat, cow, and pig feces. Recovered sequences were related to Enterobacteriaceae (47%), Helicobacter (26%), Catellicoccus (11%), Fusobacterium (11%), and Campylobacter (5%). Three PCR assays, designated GFB, GFC, and GFD, were based on recovered sequence fragments. Quantitative PCR assays for GFC and GFD were developed using SYBR green. GFC detected down to 0.1 mg gull feces/100 ml (corresponding to 2 gull enterococci most probable number [MPN]/100 ml). GFD detected down to 0.1 mg chicken feces/100 ml (corresponding to 13 Escherichia coli MPN/100 ml). GFB and GFC were 97% and 94% specific to gulls, respectively. GFC cross-reacted with 35% of sheep samples but occurred at about 100,000 times lower concentrations in sheep. GFD was 100% avian specific and occurred in gulls, geese, chickens, and ducks. In the United States, Canada, and New Zealand, the three markers differed in their geographic distributions but were found across the range tested. These assays detected four important bird groups contributing to fecal contamination of waterways: gulls, geese, ducks, and chickens. Marker distributions across North America and in New Zealand suggest that they will have broad applicability in other parts of the world as well. PMID:22081573

  14. Hybridization among Arctic white-headed gulls (Larus spp.) obscures the genetic legacy of the Pleistocene

    USGS Publications Warehouse

    Sonsthagen, Sarah A.; Chesser, R. Terry; Bell, Douglas A.; Dove, Carla J.

    2012-01-01

    We studied the influence of glacial oscillations on the genetic structure of seven species of white-headed gull that breed at high latitudes (Larus argentatus, L. canus, L. glaucescens, L. glaucoides, L. hyperboreus, L. schistisagus, and L. thayeri). We evaluated localities hypothesized as ice-free areas or glacial refugia in other Arctic vertebrates using molecular data from 11 microsatellite loci, mitochondrial DNA (mtDNA) control region, and six nuclear introns for 32 populations across the Holarctic. Moderate levels of genetic structure were observed for microsatellites (FST= 0.129), introns (ΦST= 0.185), and mtDNA control region (ΦST= 0.461), with among-group variation maximized when populations were grouped based on subspecific classification. Two haplotype and at least two allele groups were observed across all loci. However, no haplotype/allele group was composed solely of individuals of a single species, a pattern consistent with recent divergence. Furthermore, northernmost populations were not well differentiated and among-group variation was maximized when L. argentatus and L. hyberboreus populations were grouped by locality rather than species, indicating recent hybridization. Four populations are located in putative Pleistocene glacial refugia and had larger t estimates than the other 28 populations. However, we were unable to substantiate these putative refugia using coalescent theory, as all populations had genetic signatures of stability based on mtDNA. The extent of haplotype and allele sharing among Arctic white-headed gull species is noteworthy. Studies of other Arctic taxa have generally revealed species-specific clusters as well as genetic structure within species, usually correlated with geography. Aspects of white-headed gull behavioral biology, such as colonization ability and propensity to hybridize, as well as their recent evolutionary history, have likely played a large role in the limited genetic structure observed.

  15. Vigilance and feeding behaviour in large feeding flocks of laughing gulls, Larus atricilla, on Delaware Bay

    NASA Astrophysics Data System (ADS)

    Burger, Joanna; Gochfeld, Michael

    1991-02-01

    Laughing gulls ( Larus atricilla) forage on horseshoe crab ( Limulus polyphemus) eggs during May in Delaware Bay each year. They feed in dense flocks, and foraging rates vary with vigilance, bird density, number of steps and location in the flock, whereas time devoted to vigilance is explained by number of steps, density, location and feeding rates. The time devoted to vigilance decreases with increasing density, increasing foraging rates and decreasing aggression. Birds foraging on the edge of flocks take fewer pecks and more steps, and devote more time to vigilance than those in the intermediate or central parts of a flock.

  16. Wave spectra of a shoaling wave field: A comparison of experimental and simulated results

    NASA Technical Reports Server (NTRS)

    Morris, W. D.; Grosch, C. E.; Poole, L. R.

    1982-01-01

    Wave profile measurements made from an aircraft crossing the North Carolina continental shelf after passage of Tropical Storm Amy in 1975 are used to compute a series of wave energy spectra for comparison with simulated spectra. Results indicate that the observed wave field experiences refraction and shoaling effects causing statistically significant changes in the spectral density levels. A modeling technique is used to simulate the spectral density levels. Total energy levels of the simulated spectra are within 20 percent of those of the observed wave field. The results represent a successful attempt to theoretically simulate, at oceanic scales, the decay of a wave field which contains significant wave energies from deepwater through shoaling conditions.

  17. Comparing wave shoaling methods used in large-scale coastal evolution modeling

    NASA Astrophysics Data System (ADS)

    Limber, P. W.; Adams, P. N.; Murray, A.

    2013-12-01

    A variety of methods are available to simulate wave propagation from the deep ocean to the surf zone. They range from simple and computationally fast (e.g. linear wave theory applied to shore-parallel bathymetric contours) to complicated and computationally intense (e.g., Delft's ';Simulating WAves Nearshore', or SWAN, model applied to complex bathymetry). Despite their differences, the goal of each method is the same with respect to coastline evolution modeling: to link offshore waves with rates of (and gradients in) alongshore sediment transport. Choosing a shoaling technique for modeling coastline evolution should be partly informed by the spatial and temporal scales of the model, as well as the model's intent (is it simulating a specific coastline, or exploring generic coastline dynamics?). However, the particular advantages and disadvantages of each technique, and how the advantages/disadvantages vary over different model spatial and temporal scales, are not always clear. We present a wave shoaling model that simultaneously computes breaking wave heights and angles using three increasingly complex wave shoaling routines: the most basic approach assuming shore-parallel bathymetric contours, a wave ray tracing method that includes wave energy convergence and divergence and non-shore-parallel contours, and a spectral wave model (SWAN). Initial results show reasonable agreement between wave models along a flat shoreline for small (1 m) wave heights, low wave angles (0 to 10 degrees), and simple bathymetry. But, as wave heights and angles increase, bathymetry becomes more variable, and the shoreline shape becomes sinuous, the model results begin to diverge. This causes different gradients in alongshore sediment transport between model runs employing different shoaling techniques and, therefore, different coastline behavior. Because SWAN does not approximate wave breaking (which drives alongshore sediment transport) we use a routine to extract grid cells from SWAN

  18. Multiple S-isotopic evidence for episodic shoaling of anoxic water during Late Permian mass extinction

    PubMed Central

    Shen, Yanan; Farquhar, James; Zhang, Hua; Masterson, Andrew; Zhang, Tonggang; Wing, Boswell A.

    2011-01-01

    Global fossil data show that profound biodiversity loss preceded the final catastrophe that killed nearly 90% marine species on a global scale at the end of the Permian. Many hypotheses have been proposed to explain this extinction and yet still remain greatly debated. Here, we report analyses of all four sulphur isotopes (32S, 33S, 34S and 36S) for pyrites in sedimentary rocks from the Meishan section in South China. We observe a sulphur isotope signal (negative δ34S with negative Δ33S) that may have resulted from limitation of sulphate supply, which may be linked to a near shutdown of bioturbation during shoaling of anoxic water. These results indicate that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe. Our data suggest a prolonged deterioration of oceanic environments during the Late Permian mass extinction. PMID:21343928

  19. Multiple S-isotopic evidence for episodic shoaling of anoxic water during Late Permian mass extinction.

    PubMed

    Shen, Yanan; Farquhar, James; Zhang, Hua; Masterson, Andrew; Zhang, Tonggang; Wing, Boswell A

    2011-01-01

    Global fossil data show that profound biodiversity loss preceded the final catastrophe that killed nearly 90% marine species on a global scale at the end of the Permian. Many hypotheses have been proposed to explain this extinction and yet still remain greatly debated. Here, we report analyses of all four sulphur isotopes ((32)S, (33)S, (34)S and (36)S) for pyrites in sedimentary rocks from the Meishan section in South China. We observe a sulphur isotope signal (negative δ(34)S with negative Δ(33)S) that may have resulted from limitation of sulphate supply, which may be linked to a near shutdown of bioturbation during shoaling of anoxic water. These results indicate that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe. Our data suggest a prolonged deterioration of oceanic environments during the Late Permian mass extinction. PMID:21343928

  20. Corrective Action Investigation Plan for Corrective Action Unit 447: Project Shoal Area, Nevada Subsurface Site

    SciTech Connect

    DOE /NV

    1998-11-01

    This Corrective Action Investigation Plan (CAIP) describes the US Department of Energy's (DOE's) continued environmental investigation of the subsurface Project Shoal Area (PSA) Corrective Action Unit (CAU) 447. The PSA is located in the Sand Springs Mountains in Churchill County, Nevada, about 48 kilometers (km) (30 miles [mi]) southeast of Fallon, Nevada. Project Shoal was part of the Vela Uniform Program which was conducted to improve the US' ability to detect, identify, and locate underground nuclear detonations. The test consisted of detonating a 12-kiloton nuclear device deep underground in granitic rock to determine whether seismic waves produced by an underground nuclear test could be differentiated from seismic waves produced by a naturally occurring earthquake. The test was a joint effort conducted by the US Atomic Energy Commission (AEC) and the US Department of Defense (DoD) in October 1963 (AEC, 1964).

  1. Sediment resuspension and nepheloid layers induced by long internal solitary waves shoaling orthogonally on uniform slopes

    NASA Astrophysics Data System (ADS)

    Bourgault, D.; Morsilli, M.; Richards, C.; Neumeier, U.; Kelley, D. E.

    2014-01-01

    Two-dimensional, nonlinear and nonhydrostatic field-scale numerical simulations are used to examine the resuspension, dispersal and transport of mud-like sediment caused by the shoaling and breaking of long internal solitary waves on uniform slopes. The patterns of erosion and transport are both examined, in a series of test cases with varying conditions. Shoreward sediment movement is mainly within boluses, while seaward movement is within intermediate nepheloid layers. Several relationships between properties of the suspended sediment and control parameters are determined such as the horizontal extent of the nehpeloid layers, the total mass of resuspended sediment and the point of maximum bed erosion. The numerical results provide a plausible explanation for acoustic backscatter patterns observed during and after the shoaling of internal solitary wavetrains in a natural coastal environment. The results may be useful in the interpretation of some sedimentary structures, and suggest an effective mechanism for offshore dispersal of muddy sediments.

  2. Leadership emergence in a data-driven model of zebrafish shoals with speed modulation

    NASA Astrophysics Data System (ADS)

    Zienkiewicz, A.; Barton, D. A. W.; Porfiri, M.; Di Bernardo, M.

    2015-11-01

    Models of collective animal motion can greatly aid in the design and interpretation of behavioural experiments that seek to unravel, isolate, and manipulate the determinants of leader-follower relationships. Here, we develop an initial model of zebrafish social behaviour, which accounts for both speed and angular velocity regulatory interactions among conspecifics. Using this model, we analyse the macroscopic observables of small shoals influenced by an "informed" agent, showing that leaders which actively modulate their speed with respect to their neighbours can entrain and stabilise collective dynamics of the naïve shoal. Supplementary material in the form of two mp4 files available from the Journal web page at http://dx.doi.org/10.1140/epjst/e2015-50093-5

  3. Diurnal trends in the mid-water biomass community of the Northwestern Hawaiian Islands observed acoustically

    NASA Astrophysics Data System (ADS)

    Lammers, Marc O.; Brainard, Russell E.; Au, Whitlow W. L.

    2004-10-01

    The nighttime mid-water biomass occurring near six banks in the Northwestern Hawaiian Islands was investigated using 38- and 120-kHz EK60 echosounders. Locations investigated included: French Frigate Shoals, Maro Reef, Lisianksi Island/Neva Shoals, Pearl and Hermes Atoll, Kure Atoll and Midway Atoll. Surveys were designed to sample transect lines parallel and normal to shore between 10 p.m. and 7 a.m. and once during daylight hours. A diurnal trend was found in the occurrence of mid-water sound scattering organisms at all six locations. Communities of organisms accumulate at night on the edges of each island between the 20- and 100-fathom isobaths. The highest densities of organisms restrict their horizontal movements to depths of 20 fathoms or deeper, but increases in biomass were also observed at shallower depths. The northern islands of Kure, Midway, and Pearl and Hermes Atolls exhibited patchier distributions than the southern islands. The composition of the biomass is presently unclear but resembles the mesopelagic boundary community found near the Main Hawaiian Islands. Simultaneous observations with the TOAD camera system revealed clouds of zooplankton mixed with small fish and other micronekton. The nightly influx of these organisms is likely a significant, though poorly understood, component of these islands ecosystems.

  4. A cellular automata model for population expansion of Spartina alterniflora at Jiuduansha Shoals, Shanghai, China

    NASA Astrophysics Data System (ADS)

    Huang, Hua-mei; Zhang, Li-quan; Guan, Yu-juan; Wang, Dong-hui

    2008-03-01

    Biological invasion has received considerable attention recently because of increasing impacts on local ecosystems. Expansion of Spartina alterniflora, a non-native species, on the intertidal mudflats of Jiuduansha Shoals at the Yangtze River Estuary is a prime example of a spatially-structured invasion in a relatively simple habitat, for which strategic control efforts can be modeled and applied. Here, we developed a Cellular Automata (CA) model, in conjunction with Remote Sensing and Geographical Information Systems, to simulate the expanding process of S. alterniflora for a period of 8 years after being introduced to the new shoals, and to study the interactions between spatial pattern and ecosystem processes for the saltmarsh vegetation. The results showed that the CA model could simulate the population dynamics of S. alterniflora and Phragmites australis on the Jiuduansha Shoals successfully. The results strongly support the hypothesis of space pre-emption as well as range expansion with simple advancing wave fronts for these two species. In the Yangtze River Estuary, the native species P. australis shares the same niche with the exotic species S. alterniflora. However, the range expansion rate of P. australis was much slower than that of S. alterniflora. With the accretion of the Jiuduansha Shoals due to the large quantity of sediments deposited by the Yangtze River, a rapid range expansion of S. alterniflora is predicted to last for a long period into future. This study indicated the potential for this approach to provide valuable insights into population and community ecology of invasive species, which could be very important for wetland biodiversity conservation and resource management in the Yangtze River Estuary and other such impacted areas.

  5. The coastline remote sensing survey for Zhao Shu Island in Xisha Islands based on WorldView-2

    NASA Astrophysics Data System (ADS)

    Li, Li; Zhong, Chang; Kong, Fanping

    2014-11-01

    Due to diastrophism, tide action and human activities, the coastline is always in flux. There are lots of coral islands in the south sea of China. Remote sensing survey for the coastline not only can reassert the necessity and importance of coral protection, but also can provide basic data and scientific basis for island ecologic protection, reasonable utilization of land resources. The study area named Zhao Shu Island lies in Jintong Islands of Xisha. It is a coral island which has people inhabited. Using WorldView-2 satellite remote sensing images as data sources we carry out three phases of coastline investigation and monitoring. The satellite data phases are 2002, 2010 and 2013. Firstly, affirm the bands valuable for color composition on the basis of spectral and correlation analysis. Then extract the coastline by a series of image process, such as image correction, fusion, waterline extraction and coastline revision. Finally determine the coastline types and length by artificial interpretation. The results show that the island length is gradually smaller, which means the island area is reducing. The beach bedrock coast in northern island was eroded seriously especially during the period between 2010 and 2013. In addition, the shoal head shape in the western island changed a lot.

  6. Familiarity affects social network structure and discovery of prey patch locations in foraging stickleback shoals

    PubMed Central

    Atton, N.; Galef, B. J.; Hoppitt, W.; Webster, M. M.; Laland, K. N.

    2014-01-01

    Numerous factors affect the fine-scale social structure of animal groups, but it is unclear how important such factors are in determining how individuals encounter resources. Familiarity affects shoal choice and structure in many social fishes. Here, we show that familiarity between shoal members of sticklebacks (Gasterosteus aculeatus) affects both fine-scale social organization and the discovery of resources. Social network analysis revealed that sticklebacks remained closer to familiar than to unfamiliar individuals within the same shoal. Network-based diffusion analysis revealed that there was a strong untransmitted social effect on patch discovery, with individuals tending to discover a task sooner if a familiar individual from their group had previously done so than if an unfamiliar fish had done so. However, in contrast to the effect of familiarity, the frequency with which individuals had previously associated with one another had no effect upon the likelihood of prey patch discovery. This may have been due to the influence of fish on one another's movements; the effect of familiarity on discovery of an empty ‘control’ patch was as strong as for discovery of an actual prey patch. Our results demonstrate that factors affecting fine-scale social interactions can also influence how individuals encounter and exploit resources. PMID:25009061

  7. Shoaling of internal solitary waves at the ASIAEX site in the South China Sea

    NASA Astrophysics Data System (ADS)

    Warn-Varnas, A.; Lamb, K.

    2012-04-01

    The interaction of barotropic tides with Luzon Strait topography generates westward propagating internal bores and solitary waves trains which eventually shoal and dissipate on the western side of the South China Sea. Numerical simulations of this shoaling process at the site of the Asian Seas International Acoustic Experiment (ASIAEX) have been undertaken in order to investigate the sensitivity of the shoaling process on a variety of environmental factors. The model parameters of the Luzon Strait region are tuned to yield solitary wave trains similar to those observed in the ASIAEX experiments. The sensitivity to details of the stratification, bathymetry, deep water depth and initial wave amplitude as well as the effects of dissipation in a bottom boundary layer are considered. On the slope secondary solitary waves are generated which propagate towards the shelf. In the vicinity of the shelf break a leading square-shaped wave of depression forms which is followed by a series of square-shaped waves of elevation in inviscid simulation. The presence of a bottom boundary significantly modifies the waves trailing the leading depression resulting in the emergence of many more smaller waves. Comparison against the measurements of Orr and Mignerey (2003) are conducted.

  8. Evaluation of dredged material proposed for ocean Disposal from Shoal Harbor/Compton Creek Project Area

    SciTech Connect

    Gardiner, W.W.; Borde, A.B.; Nieukirk, S.L.; Barrows, E.S.; Gruendell, B.D.; Word, J.Q.

    1996-10-01

    The objective of the Shoal Harbor/Compton Creek Project was to evaluate proposed dredged material from the Shoal harbor/Compton Creek Project Area in Belford and Monmouth, New Jersey to determine its suitability for unconfined ocean disposal at the Mud Dump Site. This was one of five waterways that the US Army Corps of Engineers- New York District requested the Battelle Marine Sciences Laboratory (MSL) to sample and evaluate for dredging and disposal in May 1995. The evaluation of proposed dredged material from the Shoal Harbor/Compton Creek Project area consisted of bulk chemical analyses, chemical analyses of dredging site water and elutriate, benthic and water-column acute toxicity tests and bioaccumulation studies. Eleven core samples were analyzed or grain size, moisture content, and total organic carbon. Other sediments were evaluated for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congers, polynuclear aromatic hydrocarbons, and 1,4- dichlorobenzene. Dredging site water and elutriate water were analyzed for metals, pesticides, and PCBs.

  9. Levels of DDT and PCB's in different stages of life cycle of the arctic tern Sterna paradisaea and the herring gull Larus argentatus

    SciTech Connect

    Lemmetyinen, R.; Rantamaki, P.; Karlin, A.

    1982-01-01

    ..sigma..DDT and PCB levels were analyzed in samples of arctic terns and herring gulls collected in the archipelago of southwestern Finland. Special attention was paid to the levels at various stages of the life cycle and in different sexes. The levels were nearly ten times higher in the herring gull. The highest loads were found in adult birds and in newly hatched chicks but the levels were much lower (only 7-12 % in the herring gull) in chicks just before fledgling. The levels in young gulls remained low until the end of August at least. Therefore it is plausible that the high levels found in adult gulls are a consequence of their wintering in the southern Baltic. The levels of ..sigma..DDT and PCB residues were significantly lower in female arctic terns than in male terns. Differences between the sexes were small in the herring gull. Thus it is possible that the female of the arctic tern is able to release pollutants, especially PCB residues, more effectively into eggs than the female of the herring gull. The biochemical mechanisms involved are not clear but a possible explanation may be different lipoprotein structures in the eggs of the species.

  10. Perfluoroalkyl and polyfluoroalkyl substances in entire clutches of Audouin's gulls from the Ebro Delta.

    PubMed

    Vicente, Joana; Sanpera, Carola; García-Tarrasón, Manuel; Pérez, Alba; Lacorte, Silvia

    2015-01-01

    The aim of the present study was to determine the distribution of per- and polyfluoroalkyl substances (PFASs) in three-egg clutches of Audouin's gull (Larus audouinii) breeding in Ebro Delta's colony according to the laying order (a, b and c eggs). Five PFASs were analyzed in 30 eggs (yolk and albumen separately), corresponding to 10 three-egg clutches. Carbon and nitrogen stable isotopes were measured as dietary tracers. PFASs were not detected in albumen. In egg yolks, perfluorooctane sulfonate (PFOS) was the main compound detected followed by perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHS) and perfluorooctanoic acid (PFOA). Perfluorooctane sulfonate (PFBS) was not detected. Mean ΣPFASs for a-eggs was of 236±57 ng g(-1) yolk wet weight (ww), for b-eggs was of 140±56 ng g(-1) yolk ww and for c-eggs, 133±54 ng g(-1) yolk ww. PFOS concentration decreased according to the laying order of the eggs, showing significant differences between consecutive eggs. In addition, significant correlation (rs2=0.7-0.9) was observed for PFOS concentration within the eggs from the same clutch. No relationship was found between PFOS levels and stable isotopes signatures. Capsule: In Audouin gull's eggs, PFOS was the main PFASs detected and its concentration decreased according to the laying sequence. PMID:24815900

  11. Feathered Detectives: Real-Time GPS Tracking of Scavenging Gulls Pinpoints Illegal Waste Dumping

    PubMed Central

    Grémillet, David; Afán, Isabel; Ramírez, Francisco; Bouten, Willem; Forero, Manuela G.

    2016-01-01

    Urban waste impacts human and environmental health, and waste management has become one of the major challenges of humanity. Concurrently with new directives due to manage this human by-product, illegal dumping has become one of the most lucrative activities of organized crime. Beyond economic fraud, illegal waste disposal strongly enhances uncontrolled dissemination of human pathogens, pollutants and invasive species. Here, we demonstrate the potential of novel real-time GPS tracking of scavenging species to detect environmental crime. Specifically, we were able to detect illegal activities at an officially closed dump, which was visited recurrently by 5 of 19 GPS-tracked yellow-legged gulls (Larus michahellis). In comparison with conventional land-based surveys, GPS tracking allows a much wider and cost-efficient spatiotemporal coverage, even of the most hazardous sites, while GPS data accessibility through the internet enables rapid intervention. Our results suggest that multi-species guilds of feathered detectives equipped with GPS and cameras could help fight illegal dumping at continental scales. We encourage further experimental studies, to infer waste detection thresholds in gulls and other scavenging species exploiting human waste dumps. PMID:27448048

  12. Feathered Detectives: Real-Time GPS Tracking of Scavenging Gulls Pinpoints Illegal Waste Dumping.

    PubMed

    Navarro, Joan; Grémillet, David; Afán, Isabel; Ramírez, Francisco; Bouten, Willem; Forero, Manuela G

    2016-01-01

    Urban waste impacts human and environmental health, and waste management has become one of the major challenges of humanity. Concurrently with new directives due to manage this human by-product, illegal dumping has become one of the most lucrative activities of organized crime. Beyond economic fraud, illegal waste disposal strongly enhances uncontrolled dissemination of human pathogens, pollutants and invasive species. Here, we demonstrate the potential of novel real-time GPS tracking of scavenging species to detect environmental crime. Specifically, we were able to detect illegal activities at an officially closed dump, which was visited recurrently by 5 of 19 GPS-tracked yellow-legged gulls (Larus michahellis). In comparison with conventional land-based surveys, GPS tracking allows a much wider and cost-efficient spatiotemporal coverage, even of the most hazardous sites, while GPS data accessibility through the internet enables rapid intervention. Our results suggest that multi-species guilds of feathered detectives equipped with GPS and cameras could help fight illegal dumping at continental scales. We encourage further experimental studies, to infer waste detection thresholds in gulls and other scavenging species exploiting human waste dumps. PMID:27448048

  13. Geographical distribution of organochlorine contaminants and reproductive parameters in Herring Gulls on Lake Superior in 1983.

    PubMed

    Chip Weseloh, D V; Ewins, P J; Struger, J; Mineau, P; Norstrom, R J

    1994-02-01

    As part of the Great Lakes International Surveillance Plan, 1978-83, egg contaminant levels and reproductive output were determined for Herring Gull colonies on Lake Superior in 1983. Since 1974, the Herring Gull has been widely used in the Great Lakes as a spatial and temporal monitor of organochlorine (OC) contaminant levels and associated biological effects. Most eggs contained a wide range of OCs, the main compounds being DDE, polychlorinated biphenyls (PCBs), dieldrin, heptachlor epoxide, oxychlordane, hexachlorobenzene and mirex. Levels of an additional ten OCs and five polychlorinated dibenzo-p-dioxin (PCDD) congeners were also determined for some sites. Overall, levels varied significantly among colonies, but there was no obvious relationship to spatial distribution of contaminants in sediments or fish species. OC levels in eggs had declined by up to 84% since 1974. Eggshells were only 8% thinner than before the introduction of DDT, and shell thinning was not a cause of breeding failure. Average reproductive output varied from 0.15 to 1.57 young per apparently occupied nest in 1983: at 56% of colonies the value was below that thought necessary to maintain stable populations. The main causes of failure were egg disappearence and cannibalism of chicks. Despite this, the population appeared to have been increasing at about 4% per annum. Reduced availability of forage fish during the early 1980s was the most likely reason for the poor reproductive output in 1983. PMID:24221346

  14. Organochlorine-associated immunosuppression in prefledgling Caspian terns and herring gulls from the Great Lakes: an ecoepidemiological study.

    PubMed Central

    Grasman, K A; Fox, G A; Scanlon, P F; Ludwig, J P

    1996-01-01

    The objectives of study were to determine whether contaminant-associated immunosuppression occurs in prefledgling herring gulls and Caspian terns from the Great Lakes and to evaluate immunological biomarkers for monitoring health effects in wild birds. During 1992 to 1994, immunological responses and related variables were measured in prefledgling chicks at colonies distributed across a broad gradient of organochlorine contamination (primarily polychlorinated biphenyls), which was measured in eggs. The phytohemagglutinin skin test was used to assess T-lymphocyte function. In both species, there was a strong exposure-response relationship between organochlorines and suppressed T-cell-mediated immunity. Suppression was most severe (30-45%) in colonies in Lake Ontario (1992) and Saginaw Bay (1992-1994) for both species and in western Lake Erie (1992) for herring gulls. Both species exhibited biologically significant differences among sites in anti-sheep red blood cells antibody titers, but consistent exposure-response relationships with organochlorines were not observed. In Caspian terns and, to a lesser degree, in herring gulls, there was an exposure-response relationship between organochlorines and reduced plasma retinol (vitamin A). In 1992, altered White blood cell numbers were associated with elevated organochlorine concentrations in Caspian terns but not herring gulls. The immunological and hematological biomarkers used in this study revealed contaminant-associated health effects in wild birds. An epidemiological analysis strongly supported the hypothesis that suppression of T-cell-mediated immunity was associated with high perinatal exposure to persistent organochlorine contaminants. PMID:8880006

  15. Comparison of Extended-Spectrum β-Lactamase (ESBL) CTX-M Genotypes in Franklin Gulls from Canada and Chile

    PubMed Central

    Waldenström, Jonas; Svensson, Lovisa; Drobni, Mirva; Olsen, Björn

    2015-01-01

    Migratory birds have been suggested to contribute to long-distance dispersal of antimicrobial resistant bacteria, but tests of this hypothesis are lacking. In this study we determined resistance profiles and genotypes of ESBL-producing bacteria in randomly selected Escherichia coli from Franklin´s gulls (Leucophaeus pipixcan) at breeding sites in Canada and compared with similar data from the gulls' wintering grounds in Chile. Resistant E. coli phenotypes were common, most notably to ampicillin (30.1%) and cefadroxil (15.1%). Furthermore, 17.0% of the gulls in Canada carried ESBL producing bacteria, which is higher than reported from human datasets from the same country. However, compared to gulls sampled in Chile (30.1%) the prevalence of ESBL was much lower. The dominant ESBL variants in Canada were blaCTX-M-14 and blaCTX-M-15 and differed in proportions to the data from Chile. We hypothesize that the observed differences in ESBL variants are more likely linked to recent exposure to bacteria from anthropogenic sources, suggesting high local dissemination of resistant bacteria both at breeding and non-breeding times rather than a significant trans-hemispheric exchange through migrating birds. PMID:26496629

  16. Molecular characterization and phylogenetics of a reassortant H13N8 influenza virus isolated from gulls in Mongolia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A double reassortant H13N8 influenza A virus was isolated from gulls in Mongolia. The basic virological characteristics were studied. Complete genome sequence analysis indicated the complicated evolutionary history. The PA gene belongs to classical Avian-like lineage and more likely originated fro...

  17. Entrainment of Dungeness Crab in the Desdemona Shoals Reach of the Lower Columbia River Navigation Channel

    SciTech Connect

    Pearson, Walter H.; Kohn, Nancy P.; Skalski, J. R.

    2006-09-30

    Proposed dredging of the Columbia River has raised concerns about related impacts on Dungeness crab in the Columbia River Estuary (CRE). This study follows two major efforts, sponsored by the Portland District of the U. S. Army Corps of Engineers (USACE) to quantify the number of crabs entrained by a hopper dredge working in the CRE. From June 2002 through September 2002, Pacific Northwest National Laboratory (PNNL) conducted direct measurements of crab entrainment in the CRE from the mouth of the Columbia River (MCR, river mile -3 to +3) upriver as far as Miller Sands (river mile 21 to 24). These studies constituted a major step in quantifying crab entrainment in the CRE, and allowed statistically bounded projections of adult equivalent loss (AEL) for Dungeness crab populations under a range of future construction dredging and maintenance dredging scenarios (Pearson et al. 2002, 2003). In 2004, PNNL performed additional measurements to improve estimates of crab entrainment at Desdemona Shoals and at Flavel Bar, a reach near Astoria that had not been adequately sampled in 2002 (Figure 1). The 2004 data were used to update the crab loss projections for channel construction to 43 ft MLLW. In addition, a correlation between bottom salinity and adult (age 2+ and 3+, >100 mm carapace width) crab entrainment was developed using 2002 data, and elaborated upon with the 2004 data. This crab salinity model was applied to forecasting seasonal (monthly) entrainment rates and AEL using seasonal variations in salinity (Pearson et al. 2005). In the previous studies, entrainment rates in Desdemona Shoals were more variable than in any of the other reaches. Pearson et al. (2005) concluded that ?the dynamics behind the variable entrainment rates at Desdemona Shoals are not fully understood,? as well as finding that juvenile crab entrainment was not significantly correlated with salinity as it was for older crab. The present study was undertaken to address the question of whether the

  18. High Prevalence of SXT/R391-Related Integrative and Conjugative Elements Carrying blaCMY-2 in Proteus mirabilis Isolates from Gulls in the South of France.

    PubMed

    Aberkane, Salim; Compain, Fabrice; Decré, Dominique; Dupont, Chloé; Laurens, Chrislène; Vittecoq, Marion; Pantel, Alix; Solassol, Jérôme; Carrière, Christian; Renaud, François; Brieu, Nathalie; Lavigne, Jean-Philippe; Bouzinbi, Nicolas; Ouédraogo, Abdoul-Salam; Jean-Pierre, Hélène; Godreuil, Sylvain

    2016-02-01

    The genetic structures involved in the dissemination of blaCMY-2 carried by Proteus mirabilis isolates recovered from different gull species in the South of France were characterized and compared to clinical isolates. blaCMY-2 was identified in P. mirabilis isolates from 27/93 yellow-legged gulls and from 37/65 slender-billed gulls. It was carried by a conjugative SXT/R391-like integrative and conjugative element (ICE) in all avian strains and in 3/7 human strains. Two clinical isolates had the same genetic background as six avian isolates. PMID:26643344

  19. Evaluation of the SHOALS 1000T Bathymetric LIDAR System for Monitoring Channel Sediment Within the Colorado River in Arizona

    NASA Astrophysics Data System (ADS)

    Davis, P. A.; Gonzales, F. M.; Brown, K. M.; Melis, T. S.

    2005-12-01

    The Grand Canyon Monitoring and Research Center of the U.S. Geological Survey monitors sediment transport and storage within the Colorado River ecosystem in Arizona in order to develop flow protocols for the Glen Canyon dam that preserve or restore aquatic and terrestrial habitats. Currently, monitoring the channel sediments is accomplished using acoustic multi-beam surveys, which are very time-consuming. We explored more efficient collection systems that could provide a 2-m point spacing and a vertical accuracy of 25 cm or better. The dual-beam SHOALS 1000T LIDAR system, which simultaneously collects bathymetric and topographic data, could meet these requirements if flown at a 300 m altitude. This low altitude required this fixed-wing system to be modified for helicopter collection to navigate the sinuous, steep-walled canyon. We tested the helicopter-based SHOALS on two segments of the Colorado River - the San Juan River confluence at Lake Powell and the southern portion of Glen Canyon near Lees Ferry. The test flights occurred in late November after a high-flow dam experiment. Early winter storms injected such large volumes of sediment into the unmanaged San Juan River that the SHOALS green laser could not penetrate the water's surface. The water at Lees Ferry was relatively clear (Secchi depths of 7-7.5 m) because there are no tributaries between Lees Ferry and Glen Canyon dam and because the dam maintained a low steady flow for a week following the high-flow experiment in order for ground and aerial surveys to collect monitoring data. At a 300 m altitude, the SHOALS scanner produced a 60-m ground swath. Seven separate flight lines were collected - more than necessary to cover the 100-m-wide channel. Three GPS stations were operated within 30 km of the test flights. Within the areas of overlap between each pair of the seven SHOALS flight lines we found the reproducibility of the SHOALS data to be 19 cm in the channel and 21 cm on land. At Lees Ferry, 20 land

  20. Novel flame retardants in urban-feeding ring-billed gulls from the St. Lawrence River, Canada.

    PubMed

    Gentes, Marie-Line; Letcher, Robert J; Caron-Beaudoin, Elyse; Verreault, Jonathan

    2012-09-01

    This study investigated the occurrence of a comprehensive suite of polybrominated diphenyl ethers (PBDEs) and current-use flame retardants (FRs) in ring-billed gulls breeding in a highly industrialized section of the St. Lawrence River, downstream from Montreal (QC, Canada). Despite major point-sources and diffuse contamination by FRs, nearly no FR data have been reported in birds from this area. Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (BEHTBP) was detected in 89% of ring-billed gull livers (mean: 2.16 ng/g ww; max: 17.6 ng/g ww). To our knowledge, this is the highest detection frequency and highest concentrations reported thus far in any avian species or populations. Dechlorane Plus (DP) isomers were also particularly abundant (anti-DP detected in 100% and syn-DP in 93% of livers). Other detected FR compounds (3-14% detection) included 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB), hexachlorocyclopentenyl-dibromocyclooctane (HCDBCO) and β-1,2-dibromo-4-(1.2-dibromoethyl)-cyclohexane (β-TBECH). Mean BDE-209 (57.2 ± 12.2 ng/g ww) in ring-billed gull livers was unexpectedly high for this midtrophic gull species, exceeding levels reported in several apex raptors such as peregrine falcons. BDE-209's relative contribution to ∑PBDEs was on average 25% (exceeding BDE-47 and BDE-99) and contrasted with profiles typically reported for fish-eating gull species. The present study highlighted preoccupying gaps in upcoming FR regulations and stressed the need for further investigation of the sources of FR exposure in highly urbanized areas. PMID:22845168

  1. Regressive and transgressive barrier islands on the North-Central Gulf Coast — Contrasts in evolution, sediment delivery, and island vulnerability

    NASA Astrophysics Data System (ADS)

    Otvos, Ervin G.; Carter, Gregory A.

    2013-09-01

    Basic differences between non-deltaic regressive and deltaic transgressive barrier islands reflect major contrasts in geological settings and sediment sources. Two island groups on the N. Gulf of Mexico provide unique perspectives of genetic and geomorphic contrasts applicable in a worldwide context. The near-extinction of the deltaic transgressive Chandeleur barriers and reduction of the sturdier prograded Mississippi-Alabama (MS-AL) chain are related to differences in sediment sources, storm, and anthropogenic impact. 160 years of documentary evidence points to contrasting geological settings, development history, sediment sources, and island morphology as responsible for different island erodibility and life spans. The non-deltaic chain received larger volumes of coarser, less erodible medium sand from the NE Gulf coast. Onshore sand flux from reworked delta deposits received from the retreating delta shoreface initiated the fragile, thin, and isolated transgressive Chandeleur islands. Fine-grained sand from unconsolidated muds of abandoned Mississippi-St. Bernard delta lobes maintained two distinct transgressive barrier island categories. In the absence of quantitative data on cross-shore transport, discrepancies between estimated littoral drift volumes and sand reserves for nourishment remain unexplained. Medium-sandy MS-AL barriers have resisted storm events far better than delta barriers. However, even the former chain did undergo 26 to 53% area reduction since 1848. Anthropogenic intervention stymied island growth. Emerging intertidal berm-basins formed on sandy shoal platforms in storm-eliminated sectors have contributed to partial island recovery. Delta attrition by wave erosion, tectonic, and compactional subsidence had accelerated delta lobe and barrier island decay. Intensive storm erosion culminating in and following Hurricane Katrina came close to eradicate the highly vulnerable Chandeleur barrier chain. Lacking adequate nourishment, after

  2. Islands at bay: Rising seas, eroding islands, and waterbird habitat loss in Chesapeake Bay (USA)

    USGS Publications Warehouse

    Erwin, R.M.; Brinker, D.F.; Watts, B.D.; Costanzo, G.R.; Morton, D.D.

    2011-01-01

    Like many resources in the Chesapeake Bay region of the U. S., many waterbird nesting populations have suffered over the past three to four decades. In this study, historic information for the entire Bay and recent results from the Tangier Sound region were evaluated to illustrate patterns of island erosion and habitat loss for 19 breeding species of waterbirds. Aerial imagery and field data collected in the nesting season were the primary sources of data. From 1993/1994 to 2007/2008, a group of 15 islands in Tangier Sound, Virginia were reduced by 21% in area, as most of their small dunes and associated vegetation and forest cover were lost to increased washovers. Concurrently, nesting American black ducks (Anas rubripes) declined by 66%, wading birds (herons-egrets) by 51%, gulls by 72%, common terns (Sterna hirundo) by 96% and black skimmers (Rynchops niger) by about 70% in this complex. The declines noted at the larger Bay-wide scale suggest that this study area maybe symptomatic of a systemic limitation of nesting habitat for these species. The island losses noted in the Chesapeake have also been noted in other Atlantic U. S. coastal states. Stabilization and/or restoration of at least some of the rapidly eroding islands at key coastal areas are critical to help sustain waterbird communities. ?? 2010 US Government.

  3. The value and vulnerability of small estuarine islands for conserving metapopulations of breeding waterbirds

    USGS Publications Warehouse

    Erwin, R.M.; Hatfield, J.S.; Wilmers, T.J.

    1995-01-01

    Compelling arguments for preserving large habitat 'islands' have been made for a number of animal groups, but most commonly for terrestrial birds. We argue that, for many species of waterbirds nesting in coastal estuaries, maintaining numerous small islands may be a more effective management strategy than maintaining larger islands or reserves. In this study, the number of great white heron Ardea herodias nests over a 5-year period (1986-91) was negatively correlated with island area in the Florida Keys, USA. Nest densities were highest in the 210 ha island size range and lowest for islands larger than 100 ha. These small islands also attract nesting black skimmers Rynchops niger, brown pelicans Pelecanus occidentalis, and several species of terns and gulls. Small estuarine islands are vulnerable to sea level rise, erosion from watercraft, and, for dredge material islands, lack of sufficient maintenance because of competing needs for beach nourishment. Managers need to enforce more buffering and protection of these islands and argue for more dredged material allocations in some areas.

  4. The influence of predation by herring gulls Larus argentatus and oystercatchers Haematopus ostralegus on a newly established mussel Mytilus edulis bed in autumn and winter

    NASA Astrophysics Data System (ADS)

    Hilgerloh, G.; Herlyn, M.; Michaelis, H.

    1997-08-01

    Predation by herring gulls Larus argentatus and oystercatchers Haematopus ostralegus was evaluated on a newly established mussel Mytilus edulis bed on tidal flats of the German Wadden Sea. The mussel bed covered an area of 2 ha and showed a decrease in biomass of 40% in the most densely covered parts from August to January. Synchronously, the extent of the mussel bed was reduced, resulting in a decrease of average biomass of 98% over the whole mussel bed. From the beginning of August 1994 to mid January 1995, the average size of mussels increased from 10.7 to 20.3 mm. The P/B-ratio was 0.68 in August and 0.18 between September and November. Herring gulls and oystercatchers were the most important mussel predators. On average, 266 herring gulls and 63 oystercatchers were present on the mussel bed during one low tide; 34% of the herring gulls and 78% of the oystercatchers were observed to be feeding. Herring gulls fed at a rate of 4.2 mussels per minute and oystercatchers at a rate of 1.3 mussels per minute. While herring gulls took the most common mussel sizes (mean: 20 mm), oystercatchers searched for the largest mussels available (mean: 25 mm). Herring gulls consumed 13 mussels/m2 (0.3g AFDW) during one day and oystercatchers 1.7 mussels/m2 (0.1 g AFDW). Predation by birds was compensated by 33% of the production. The proportion removed by bird predation amounted to 10% of abundance and to 16% of biomass (including production). Oystercatchers were responsible for 1% of the reduction in abundance and for 3% of biomass. Removal was highest in the most common size classes of mussels, mainly caused by herring gulls. However, the highest proportion of mussels was eaten in the largest size classes, mainly by oystercatchers. *** DIRECT SUPPORT *** A03B6035 00004

  5. Increased Wounding of Southern Right Whale (Eubalaena australis) Calves by Kelp Gulls (Larus dominicanus) at Península Valdés, Argentina.

    PubMed

    Marón, Carina F; Beltramino, Lucas; Di Martino, Matías; Chirife, Andrea; Seger, Jon; Uhart, Marcela; Sironi, Mariano; Rowntree, Victoria J

    2015-01-01

    At least 626 southern right whale (Eubalaena australis) calves died at the Península Valdés calving ground, Argentina, between 2003 and 2014. Intense gull harassment may have contributed to these deaths. In the 1970s, Kelp Gulls (Larus dominicanus) began feeding on skin and blubber pecked from the backs of living right whales at Valdés. The frequency of gull attacks has increased dramatically over the last three decades and mother-calf pairs are the primary targets. Pairs attacked by gulls spend less time nursing, resting and playing than pairs not under attack. In successive attacks, gulls open new lesions on the whales' backs or enlarge preexisting ones. Increased wounding could potentially lead to dehydration, impaired thermoregulation, and energy loss to wound healing. The presence, number and total area of gull-inflicted lesions were assessed using aerial survey photographs of living mother-calf pairs in 1974-2011 (n = 2680) and stranding photographs of dead calves (n = 192) in 2003-2011. The percentage of living mothers and calves with gull lesions increased from an average of 2% in the 1970s to 99% in the 2000s. In the 1980s and 1990s, mothers and calves had roughly equal numbers of lesions (one to five), but by the 2000s, calves had more lesions (nine or more) covering a greater area of their backs compared to their mothers. Living mother-calf pairs and dead calves in Golfo Nuevo had more lesions than those in Golfo San José in the 2000s. The number and area of lesions increased with calf age during the calving season. Intensified Kelp Gull harassment at Península Valdés could be compromising calf health and thereby contributing to the high average rate of calf mortality observed in recent years, but it cannot explain the large year-to-year variance in calf deaths since 2000. PMID:26488493

  6. Increased Wounding of Southern Right Whale (Eubalaena australis) Calves by Kelp Gulls (Larus dominicanus) at Península Valdés, Argentina

    PubMed Central

    Marón, Carina F.; Beltramino, Lucas; Di Martino, Matías; Chirife, Andrea; Seger, Jon; Uhart, Marcela; Sironi, Mariano; Rowntree, Victoria J.

    2015-01-01

    At least 626 southern right whale (Eubalaena australis) calves died at the Península Valdés calving ground, Argentina, between 2003 and 2014. Intense gull harassment may have contributed to these deaths. In the 1970s, Kelp Gulls (Larus dominicanus) began feeding on skin and blubber pecked from the backs of living right whales at Valdés. The frequency of gull attacks has increased dramatically over the last three decades and mother-calf pairs are the primary targets. Pairs attacked by gulls spend less time nursing, resting and playing than pairs not under attack. In successive attacks, gulls open new lesions on the whales’ backs or enlarge preexisting ones. Increased wounding could potentially lead to dehydration, impaired thermoregulation, and energy loss to wound healing. The presence, number and total area of gull-inflicted lesions were assessed using aerial survey photographs of living mother-calf pairs in 1974–2011 (n = 2680) and stranding photographs of dead calves (n = 192) in 2003–2011. The percentage of living mothers and calves with gull lesions increased from an average of 2% in the 1970s to 99% in the 2000s. In the 1980s and 1990s, mothers and calves had roughly equal numbers of lesions (one to five), but by the 2000s, calves had more lesions (nine or more) covering a greater area of their backs compared to their mothers. Living mother-calf pairs and dead calves in Golfo Nuevo had more lesions than those in Golfo San José in the 2000s. The number and area of lesions increased with calf age during the calving season. Intensified Kelp Gull harassment at Península Valdés could be compromising calf health and thereby contributing to the high average rate of calf mortality observed in recent years, but it cannot explain the large year-to-year variance in calf deaths since 2000. PMID:26488493

  7. Effects of laughing gull and shorebird predation on the intertidal fauna at Cape May, New Jersey

    NASA Astrophysics Data System (ADS)

    Botton, M. L.

    1984-02-01

    The intertidal flats of the Cape May, New Jersey shore of Delaware Bay are populated by large numbers of laughing gulls and migrating shorebirds during the spring and early summer. Exclusion of birds from a shallow slough and a sand bar had only minor effects on the infaunal benthic invertebrate assemblage at either site. The Cape May beaches provide a rich source of food in the form of horseshoe crab ( Limulus polyphemus) eggs; foraging on this item may be more profitable than probing the sediment for infauna. Gemma gemma, a small, thick-shelled bivalve, composed over 98% of the benthic infauna at both sites in 1980, and this species may be resistant to predation by certain shorebirds, as suggested by Schneider (1978).

  8. Water balance dynamics of a boreal forest watershed: White Gull Creek basin, 1994-1996

    NASA Astrophysics Data System (ADS)

    Nijssen, Bart; Lettenmaier, Dennis P.

    2002-11-01

    Field measurements from the Boreal Ecosystem-Atmosphere Study (BOREAS) were combined to calculate the water balance of the White Gull Creek basin for the three year period 1994-1996. Evapotranspiration was mapped from the observations made at the BOREAS flux towers to the basin using a simple evaporation model with a bulk canopy resistance based on tower observations. Runoff ratios were low, and evapotranspiration accounted for most of the precipitation over the area. The accumulated storage change, over the 3 year period, was 47 mm or 3.4% of the total precipitation, but precipitation exceeded the sum of discharge and evapotranspiration by 80 mm or 15% of the precipitation in 1994. Five possible explanations for the discrepancy in the water balance are identified, with the most likely cause an underestimation of the evapotranspiration in 1994, especially during periods when the basin is wet.

  9. Nesting biology of laughing gulls in relation to agricultural chemicals in south Texas, 1978-81

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Prouty, R.M.

    1983-01-01

    Laughing Gulls (Larus atricilla) were studied along the south Texas coast during 1978-1981 to determine productivity and to evaluate the effects of environmental pollutants on reproduction. The average clutch-size was 2.6, ranging from 2.3-2.8. Sixty-six percent of the eggs hatched and 82% of the pairs hatched at least one egg. Productivity (fledglings/total nests) averaged 1.0 fledgling per nest. DDE and other organochlorine residues were low in eggs (usually <3 ppm wet weight) and were not suspected of causing reproductive problems. However, organophosphate pesticides sprayed on crops near the study areas reduced productivity by as much as 33% during 3 of 4 years, implying that certain of these chemicals may pose serious threats to the population.

  10. Exposure assessment of groundwater transport of tritium from the Shoal Site

    SciTech Connect

    Chapman, J.; Pohlmann, K.; Andricevic, R.

    1995-04-01

    The US Department of Energy (DOE) and its predecessor agencies are responsible for nuclear weapons research and development as part of the national defense program. These activities include underground nuclear testing, and a small number of such tests have been conducted at sites distant from the Nevada Test Site (NTS). An NTS site-wide Environmental Impact Statement (EIS) is being prepared in 1995 and includes the two offsite test areas in Nevada: the Shoal site and the Central Nevada Test Area. At the time of these tests, evaluations of project safety and predictions of groundwater transport of contaminants were made, and the tests were deemed safe to the public. These early evaluations were not considered sufficient for the EIS, so DOE decided to perform a new exposure assessment for the Shoal site. The basic scenario evaluated for this exposure assessment is transport of tritium from the Shoal underground nuclear test by groundwater to a receptor well where an individual drinks the contaminated water for 70 years, centered around the time of peak tritium concentration. This scenario is entirely hypothetical because, as of 1995, there are no known occurrences of humans drinking water downgradient from the test. Four specific scenarios are analyzed because of uncertainty in flowpath direction. Two of these presume that wells are drilled at the boundary of the current DOE land withdrawal and are then used for drinking water supply. Wells do not currently exist at these locations and thus the resultant risks do not apply to any current populations; however, there are no controls to prevent such wells from being drilled in the future. The two other scenarios consider transport to the first existing wells along possible flowpaths. These wells are currently used only seasonally to water cattle, and as such, these risks also do not apply to current populations.

  11. Impact of egg harvesting on breeding success of black-headed gulls, Larus ridibundus

    NASA Astrophysics Data System (ADS)

    Wood, Philippa J.; Hudson, Malcolm D.; Doncaster, C. Patrick

    2009-01-01

    Gull colonies world-wide have been harvested for their eggs for centuries with minimal knowledge of the impacts on breeding. Although most Laridae can replace lost eggs, they have comparatively high energetic demands for egg production. In this paper we assess the impacts of a licensed egg harvest on the breeding success of black-headed gulls Larus ridibundus, which nest colonially in an EU Special Protection Area in Hampshire, southern England. We compared egg volume, hatching and chick survival from harvested and un-harvested nests in central and fringe positions within colonies of various sizes, including colonies with no harvesting activity. Eggs from various laying stages were collected from harvested and un-harvested colonies of similar pre-harvest intrinsic quality, for comparison of their volumes, yolk-to-albumen ratios and eggshell thickness. Egg volume and the yolk-to-albumen ratio depended on laying time and location, with the largest eggs laid during the peak period by birds breeding in central positions on large colonies. Eggs produced by these peak layers also had the largest yolk-to-albumen ratios. Harvested sites were characterised by reductions in egg volume, yolk-to-albumen ratio and eggshell thickness, which translated to poorer hatching success and chick survival. Harvested sites also had a higher proportion of abnormal eggs, particularly taking the forms of small yolkless eggs and unpigmented eggs. The reduced breeding success on harvested colonies is likely to be linked to depletion of the female's endogenous reserves which can also reduce future survival and breeding propensity.

  12. Organohalogen and metabolically-derived contaminants and associations with whole body constituents in Norwegian Arctic glaucous gulls.

    PubMed

    Verreault, J; Shahmiri, S; Gabrielsen, G W; Letcher, R J

    2007-08-01

    Comprehensive surveys of organohalogen contaminants have been conducted in various tissues and blood of glaucous gulls (Larus hyperboreus), a top scavenger-predator species in Svalbard in the Norwegian Arctic. However, the physico-chemical properties of organohalogens (e.g., type and degree of halogenation and the presence or absence of additional phenyl group substituents) that may influence toxicokinetics, and subsequently tissue-specific accumulation, have yet to be studied in this species. We investigated the concentrations, total body burdens, and compositional patterns of legacy chlorinated compounds (PCBs and chlordanes (CHLs)), metabolically-derived PCBs (methylsulfonyl (MeSO(2))- and OH-PCBs), brominated flame retardants (polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), total-hexabromocyclododecane (HBCD)), and PBDE metabolites and/or naturally-occurring compounds with similar structures (MeO- and OH-PBDEs) in liver, blood and whole body homogenate samples of adult glaucous gulls (n=19) from Svalbard. Further, we examined the distribution of these organohalogens and metabolites in relation to whole body composition of glaucous gulls, i.e., the total water, protein, lipid and mineral contents in whole homogenate carcasses. The total body burden of organohalogens and metabolites in glaucous gulls ranged between 3.3 and 33.0 mg. Compound class distribution showed that the relative proportions of sum (Sigma) OH-PCB and SigmaOH-PBDE to the total organohalogen concentrations were significantly highest in blood. Conversely, the SigmaCHL and SigmaPCB showed generally higher proportions in the lipid-rich liver as well as in whole body homogenates. No significant difference in the compositional patterns of individual congeners/compounds was found among tissues/blood, with the exception of the classes comprised of less polar brominated compounds (PBDEs, PBBs and total-(alpha)-HBCD). Total proteins isolated from the whole body homogenates of

  13. TRIADS: A phase-resolving model for nonlinear shoaling of directional wave spectra

    NASA Astrophysics Data System (ADS)

    Sheremet, Alex; Davis, Justin R.; Tian, Miao; Hanson, Jeffrey L.; Hathaway, Kent K.

    2016-03-01

    We investigate the performance of TRIADS, a numerical implementation of a phase-resolving, nonlinear, spectral model describing directional wave evolution in intermediate and shallow water. TRIADS simulations of shoaling waves generated by Hurricane Bill, 2009 are compared to directional spectral estimates based on observations collected at the Field Research Facility of the US Army Corps Of Engineers, at Duck, NC. Both the ability of the model to capture the processes essential to the nonlinear wave evolution, and the efficiency of the numerical implementations are analyzed and discussed.

  14. Unravelling the nocturnal appearance of bogue Boops boops shoals in the anthropogenically modified shallow littoral.

    PubMed

    Mavraki, N; Georgiadis, M; Koutsikopoulos, C; Tzanatos, E

    2016-05-01

    In the present study the role of the nocturnal migration of bogue Boops boops shoals to anthropogenically modified shallow littoral locations was examined, evaluating four alternative hypotheses: (1) feeding, (2) reproduction, (3) attraction of B. boops to artificial light and (4) concealment in the darkness related to predation avoidance. All hypotheses apart from predation avoidance were rejected, as B. boops tended to concentrate in shaded locations of wider illuminated areas, a finding not only important concerning fish behaviour, but also with significant management implications. PMID:27094613

  15. Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

    SciTech Connect

    K. Pohlmann; G. Pohll; J. Chapman; A. Hassan; R. Carroll; C. Shirley

    2004-03-01

    The purpose of this work is to characterize groundwater flow and contaminant transport at the Shoal underground nuclear test through numerical modeling using site-specific hydrologic data. The ultimate objective is the development of a contaminant boundary, a model-predicted perimeter defining the extent of radionuclide-contaminated groundwater from the underground test throughout 1,000 years at a prescribed level of confidence. This boundary will be developed using the numerical models described here, after they are approved for that purpose by DOE and NDEP.

  16. Flood-inundation maps for the East Fork White River at Shoals, Indiana

    USGS Publications Warehouse

    Boldt, Justin A.

    2016-01-01

    Digital flood-inundation maps for a 5.9-mile reach of the East Fork White River at Shoals, Indiana (Ind.), were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the East Fork White River at Shoals, Ind. (USGS station number 03373500). Near-real-time stages at this streamgage may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/ or the National Weather Service (NWS) Advanced Hydrologic Prediction Service (AHPS) at http://water.weather.gov/ahps/, which also forecasts flood hydrographs at this site (NWS AHPS site SHLI3). NWS AHPS forecast peak stage information may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation.Flood profiles were computed for the East Fork White River reach by means of a one-dimensional, step-backwater model developed by the U.S. Army Corps of Engineers. The hydraulic model was calibrated by using the current stage-discharge relation (USGS rating no. 43.0) at USGS streamgage 03373500, East Fork White River at Shoals, Ind. The calibrated hydraulic model was then used to compute 26 water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum and ranging from approximately bankfull (10 ft) to the highest stage of the current stage-discharge rating curve (35 ft). The simulated water-surface profiles were then combined with a geographic information system (GIS) digital elevation model (DEM), derived from light detection and ranging (lidar) data, to delineate the area flooded at each water level. The areal extent of the 24-ft flood-inundation map was

  17. Validation, Proof-of-Concept, and Postaudit of the Groundwater Flow and Transport Model of the Project Shoal Area

    SciTech Connect

    Ahmed Hassan

    2004-09-01

    The groundwater flow and radionuclide transport model characterizing the Shoal underground nuclear test has been accepted by the State of Nevada Division of Environmental Protection. According to the Federal Facility Agreement and Consent Order (FFACO) between DOE and the State of Nevada, the next steps in the closure process for the site are then model validation (or postaudit), the proof-of-concept, and the long-term monitoring stage. This report addresses the development of the validation strategy for the Shoal model, needed for preparing the subsurface Corrective Action Decision Document-Corrective Action Plan and the development of the proof-of-concept tools needed during the five-year monitoring/validation period. The approach builds on a previous model, but is adapted and modified to the site-specific conditions and challenges of the Shoal site.

  18. Bacteriological analysis of the digestive tube of the mud snail (Bullacta exarata Philippi) and its rearing shoal

    NASA Astrophysics Data System (ADS)

    Guoliang, Wang; Tianlun, Zheng; Tongxia, Lu; Yinong, Wang; Hong, Yu; Shan, Jin

    2002-10-01

    The bacterial flora in the digestive tube of Bullacta exarata Philippi and its rearing shoal were investigated. A total of 157 strains of heterotrophic bacteria, isolated from crop, stomach intestine and other parts of the digestive tube, mainly belong to the genera Photobacterium, Bacillus, Pseudomonas Vibrio and some genera of the family Enterobacteriaceae. There are significantly more varieties of bacteria in crop than in stomach and intestine. A total of 173 strains of bacteria were isolated from the rearing shoal, belonging to 13 genera. The 5 predominant genera, such as Bacillus and Photobacterium, are the same as those in the digestive tube, but greatly differ in percentages. The number of heterotrophic bacteria and Vibrio in rearing shoal change in line with the alteration of the temperature, and are significantly affected by the use of pesticides.

  19. 46 CFR 401.407 - Basic rates and charges on Lake Erie and the navigable waters from Southeast Shoal to Port Huron...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Basic rates and charges on Lake Erie and the navigable waters from Southeast Shoal to Port Huron, MI. 401.407 Section 401.407 Shipping COAST GUARD (GREAT LAKES... Southeast Shoal to Port Huron, MI. Except as provided in § 404.420, the following basic rates are...

  20. Galapagos Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of the Galapagos Islands was acquired on March 12, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The Galapagos Islands, which are part of Ecuador, sit in the Pacific Ocean about 1000 km (620 miles) west of South America. As the three craters on the largest island (Isabela Island) suggest, the archipelago was created by volcanic eruptions, which took place millions of years ago. Unlike most remote islands in the Pacific, the Galapagos have gone relatively untouched by humans over the past few millennia. As a result, many unique species have continued to thrive on the islands. Over 95 percent of the islands' reptile species and nearly three quarters of its land bird species cannot be found anywhere else in the world. Two of the more well known are the Galapagos giant tortoise and marine iguanas. The unhindered evolutionary development of the islands' species inspired Charles Darwin to begin The Origin of Species eight years after his visit there. To preserve the unique wildlife on the islands, the Ecuadorian government made the entire archipelago a national park in 1959. Each year roughly 60,000 tourists visit these islands to experience what Darwin did over a century and a half ago. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  1. Two-dimensional numerical simulations of shoaling internal solitary waves at the ASIAEX site in the South China Sea

    NASA Astrophysics Data System (ADS)

    Lamb, K. G.; Warn-Varnas, A.

    2015-05-01

    The interaction of barotropic tides with Luzon Strait topography generates some of the world's largest internal solitary waves which eventually shoal and dissipate on the western side of the northern South China Sea. Two-dimensional numerical simulations of the shoaling of a single internal solitary wave at the site of the Asian Seas International Acoustic Experiment (ASIAEX) have been undertaken in order to investigate the sensitivity of the shoaling process to the stratification and the underlying bathymetry and to explore the influence of rotation. The bulk of the simulations are inviscid; however, exploratory simulations using a vertical eddy-viscosity confined to a near bottom layer, along with a no-slip boundary condition, suggest that viscous effects may become important in water shallower than about 200 m. A shoaling solitary wave fissions into several waves. At depths of 200-300 m the front of the leading waves become nearly parallel to the bottom and develop a very steep back as has been observed. The leading waves are followed by waves of elevation (pedestals) that are conjugate to the waves of depression ahead and behind them. Horizontal resolutions of at least 50 m are required to simulate these well. Wave breaking was found to occur behind the second or third of the leading solitary waves, never at the back of the leading wave. Comparisons of the shoaling of waves started at depths of 1000 and 3000 m show significant differences and the shoaling waves can be significantly non-adiabatic even at depths greater than 2000 m. When waves reach a depth of 200 m, their amplitudes can be more than 50% larger than the largest possible solitary wave at that depth. The shoaling behaviour is sensitive to the presence of small-scale features in the bathymetry: a 200 m high bump at 700 m depth can result in the generation of many mode-two waves and of higher mode waves. Sensitivity to the stratification is considered by using three stratifications based on summer

  2. Organohalogen contamination in breeding glaucous gulls from the Norwegian Arctic: associations with basal metabolism and circulating thyroid hormones.

    PubMed

    Verreault, Jonathan; Bech, Claus; Letcher, Robert J; Ropstad, Erik; Dahl, Ellen; Gabrielsen, Geir W

    2007-01-01

    Exposure to organohalogens in endotherms has been suggested to impose chemically induced stress by affecting functions related to maintenance energy requirements. Effects on basal metabolic rate (BMR) have been suggested to be, in part, mediated through interactions with the thyroid hormones (THs). We investigated the relationships between plasma concentrations of major organochlorines, PBDEs, hydroxylated (OH)- and methoxylated (MeO)-PBDEs and OH-PCBs, circulating TH levels and BMR in breeding glaucous gulls (Larus hyperboreus) from the Norwegian Arctic. Negative associations were found between BMR and concentrations of sigma PCB, Sigma DDT and particularly Sigma chlordane, which combined made up 91% of the total contaminant burden. Levels of THs (thyroxine and triiodothyronine) were not associated significantly with variation of BMR or concentrations of any of the compounds determined. The present study suggests that BMR may be altered in glaucous gulls exposed to high loadings of persistent contaminants in the Norwegian Arctic environment. PMID:16713050

  3. Rapid prediction of structural responses of double-bottom structures in shoal grounding scenario

    NASA Astrophysics Data System (ADS)

    Hu, Zhiqiang; Wang, Ge; Yao, Qi; Yu, Zhaolong

    2016-03-01

    This study presents a simplified analytical model for predicting the structural responses of double-bottom ships in a shoal grounding scenario. This solution is based on a series of analytical models developed from elastic-plastic mechanism theories for different structural components, including bottom girders, floors, bottom plating, and attached stiffeners. We verify this simplified analytical model by numerical simulation, and establish finite element models for a typical tanker hold and a rigid indenter representing seabed obstacles. Employing the LS-DYNA finite element solver, we conduct numerical simulations for shoal-grounding cases with a wide range of slope angles and indentation depths. In comparison with numerical simulations, we verify the proposed simplified analytical model with respect to the total energy dissipation and the horizontal grounding resistance. We also investigate the interaction effect of deformation patterns between bottom structure components. Our results show that the total energy dissipation and resistances predicted by the analytical model agree well with those from numerical simulations.

  4. Scents and scents-ability: pollution disrupts chemical social recognition and shoaling in fish

    PubMed Central

    Ward, Ashley J.W; Duff, Alison J; Horsfall, Jennifer S; Currie, Suzanne

    2007-01-01

    Chemical cues are of enormous importance in mediating the behaviour of animals, enabling them to navigate throughout their habitats, to detect the presence of predators or prey and for social recognition—identifying and discriminating between conspecifics. In many species of freshwater fish, social recognition is known to be based primarily on chemical cues. Such recognition mechanisms are vulnerable to disruption by the presence of anthropogenic contaminants in the aquatic environment. Here we show that acute exposure to low, environmentally relevant dosages of the ubiquitous contaminant, 4-nonylphenol, can seriously affect social recognition and ultimately social organization in fishes. A 1 hour 0.5 μg l−1 dose was sufficient to alter the response of members of a shoaling fish species (juvenile banded killifish, Fundulus diaphanus) to conspecific chemical cues. Dosages of 1–2 μg l−1 caused killifish to orient away from dosed conspecifics, in both a flow channel and an arena. Given the overall importance of shoaling as an adaptive strategy against predators and for locating food, it is likely that its disruption by anthropogenic contaminants would have serious implications for fishes' fitness. PMID:17956844

  5. MATURATION OF SHOALING IN TWO ZEBRAFISH STRAINS: A BEHAVIORAL AND NEUROCHEMICAL ANALYSIS

    PubMed Central

    Mahabir, Samantha; Chatterjee, Diptendu; Buske, Christine; Gerlai, Robert

    2013-01-01

    Abnormal social behavior is a hallmark of several human neuropsychiatric and neurodevelopmental disorders for which appropriate treatment is lacking. The zebrafish has been proposed as a tool with which these disorders may be modeled and their mechanisms analyzed. A potential starting point of such analyses is the identification of genetic differences between distinct zebrafish strains. Here we compare AB and TU, two well established zebrafish strains, and characterize the developmental trajectories of their shoaling (social) behavior and of the levels of dopamine, serotonin as well as a metabolite of each of these neurotransmitters, DOPAC and 5HIAA from whole brain extracts. Using a novel video-tracking software application, we demonstrate significant strain dependent changes in the maturation of shoaling between day 7 and day 87 post-fertilization. Using high-precision liquid chromatography specifically adapted to zebrafish, we uncover a significant age x strain interaction in dopamine and DOPAC that apparently correlates well with the behavioral differences found between the strains. We also report on strain differences in serotonin and 5HIAA. We discuss possible mechanistic analyses that will address causality and conclude that zebrafish will be a useful tool with which the neurobiological and genetic bases of social behavior may be analyzed in vertebrates. PMID:23518435

  6. Zebrafish response to 3D printed shoals of conspecifics: the effect of body size.

    PubMed

    Bartolini, Tiziana; Mwaffo, Violet; Showler, Ashleigh; Macrì, Simone; Butail, Sachit; Porfiri, Maurizio

    2016-04-01

    Recent progress in three-dimensional (3D) printing technology has enabled rapid prototyping of complex models at a limited cost. Virtually every research laboratory has access to a 3D printer, which can assist in the design and implementation of hypothesis-driven studies on animal behavior. In this study, we explore the possibility of using 3D printing technology to understand the role of body size in the social behavior of the zebrafish model organism. In a dichotomous preference test, we study the behavioral response of zebrafish to shoals of 3D printed replicas of varying size. We systematically vary the size of each replica without altering the coloration, aspect ratio, and stripe patterns, which are all selected to closely mimic zebrafish morphophysiology. The replicas are actuated through a robotic manipulator, mimicking the natural motion of live subjects. Zebrafish preference is assessed by scoring the time spent in the vicinity of the shoal of replicas, and the information theoretic construct of transfer entropy is used to further elucidate the influence of the replicas on zebrafish motion. Our results demonstrate that zebrafish adjust their behavior in response to variations in the size of the replicas. Subjects exhibit an avoidance reaction for larger replicas, and they are attracted toward and influenced by smaller replicas. The approach presented in this study, integrating 3D printing technology, robotics, and information theory, is expected to significantly aid preclinical research on zebrafish behavior. PMID:26891476

  7. 3D, CAEX help independent add reserves inexpensively in ship shoal area of gulf

    SciTech Connect

    Hurley, S.C.; Murphy, J.R. ); Mastorsis, S.S. )

    1993-01-18

    New exploration technologies can transform the way an independent oil company explores for hydrocarbons and develops reserves. For one independent, Murphy Exploration and Production Co. (Murphy Expro), a unit of Murphy Oil Corp., the metamorphosis began in 1988 when it launched its first comprehensive project using 3D seismic data and computer aided exploration (CAEX) workstations. In a declining 38 year oil field in the Gulf of Mexico, 3D tools and methods have enabled Murphy to increase oil and gas reserves during the past four years by 21% and 30%, respectively. Many of the new reservoirs were discovered in highly faulted complexes of relatively small, subtle traps. Further, the discoveries were accomplished with a drilling success rate of about 90% in an area where exploratory dry holes had been the rule rather than the exception. Murphy Expro has been able to maintain field production rates by adding new production at remarkably low finding costs for this region. As a result of the project's success, Murphy has committed itself to advanced oil finding technology. Between 1988 and yearend 1992 the company acquired more than 12,000 line miles of 3D seismic in five Gulf of MexIco fields including Ship Shoal 113. This article describes how the change to 3D philosophy and practice took place at Ship Shoal 113 and its impact on Murphy Expro.

  8. March 2011 Groundwater Sampling at the Project Shoal Site (Data Validation Package)

    SciTech Connect

    2011-07-01

    The U.S. Department of Energy Office of Legacy Management conducted annual sampling at the Project Shoal Area (Shoal) in March 2011. Wells HC-1, HC-2, HC-4, HC-5, HC-6, HC-7, MV-1, MV-2 and MV-3 were sampled as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PLN/S04351, continually updated). Two extra tritium samples were collected from well HC-4, one sample (HC-4-400) was collected at about 1/3 of the purge volume (135 gallons), the second sample (HC-4-400) was collected at 2/3 of purge volume (270 gallons). These additional samples were collected prior to completing the well purging process to evaluate the effects well purging has on the analytical results. Samples were not collected from locations HC-3 and HC-8 at the direction of the S.M. Stoller Corporation site lead.

  9. The breeding ecology of sea birds on Monito Island, Puerto Rico

    USGS Publications Warehouse

    Kepler, C.B.

    1978-01-01

    Monito Island, a 15-ha plateau surrounded by steep undercut cliffs, lies halfway between Puerto Rico and the Dominican Republic. Seven of the 9 sea birds are known to breed, and 2 (Blue-faced Booby and Laughing Gull) are here recorded as breeders in Puerto Rico for the first time. The Pelecaniformes are represented by 5 species, the White-tailed Tropicbird, the 3 pan-tropical boobies, and the Magnificent Frigatebird. The boobies all have long but annual breeding seasons, from fall through spring, showing a distinct breeding hiatus in the hot summer months, although some late-nesters may care for chicks during this period. The Magnificent Frigatebird has the most synchronous breeding, with a laying peak from late October to early December, when 70% of the population lay eggs. Four larids (Laughing Gull, Bridled Tern, Sooty Tern, and Brown Noddy) are summer residents vacating the island in August-September, and returning again in March-April. In general, they nest during the pelecaniform non-breeding season. The sea birds show a great range in nest site preference, with little overlap among them. Their diversity results from a combination of isolation, rugged cliffs, and the structural diversity of Monito Island. Although currently one of the outstanding sea bird colonies in the West Indies, Monito is threatened, and the colonies could be lost unless they are legally protected.

  10. Multi-laboratory evaluations of the performance of Catellicoccus marimammalium PCR assays developed to target gull fecal sources

    USGS Publications Warehouse

    Sinigalliano, Christopher D.; Ervin, Jared S.; Van De Werfhorst, Laurie C.; Badgley, Brian D.; Ballestée, Elisenda; Bartkowiaka, Jakob; Boehm, Alexandria B.; Byappanahalli, Muruleedhara N.; Goodwin, Kelly D.; Gourmelon, Michèle; Griffith, John; Holden, Patricia A.; Jay, Jenny; Layton, Blythe; Lee, Cheonghoon; Lee, Jiyoung; Meijer, Wim G.; Noble, Rachel; Raith, Meredith; Ryu, Hodon; Sadowsky, Michael J.; Schriewer, Alexander; Wang, Dan; Wanless, David; Whitman, Richard; Wuertz, Stefan; Santo Domingo, Jorge W.

    2013-01-01

    Here we report results from a multi-laboratory (n = 11) evaluation of four different PCR methods targeting the 16S rRNA gene of Catellicoccus marimammalium originally developed to detect gull fecal contamination in coastal environments. The methods included a conventional end-point PCR method, a SYBR® Green qPCR method, and two TaqMan® qPCR methods. Different techniques for data normalization and analysis were tested. Data analysis methods had a pronounced impact on assay sensitivity and specificity calculations. Across-laboratory standardization of metrics including the lower limit of quantification (LLOQ), target detected but not quantifiable (DNQ), and target not detected (ND) significantly improved results compared to results submitted by individual laboratories prior to definition standardization. The unit of measure used for data normalization also had a pronounced effect on measured assay performance. Data normalization to DNA mass improved quantitative method performance as compared to enterococcus normalization. The MST methods tested here were originally designed for gulls but were found in this study to also detect feces from other birds, particularly feces composited from pigeons. Sequencing efforts showed that some pigeon feces from California contained sequences similar to C. marimammalium found in gull feces. These data suggest that the prevalence, geographic scope, and ecology of C. marimammalium in host birds other than gulls require further investigation. This study represents an important first step in the multi-laboratory assessment of these methods and highlights the need to broaden and standardize additional evaluations, including environmentally relevant target concentrations in ambient waters from diverse geographic regions.

  11. Egg production in a coastal seabird, the glaucous-winged gull (Larus glaucescens), declines during the last century.

    PubMed

    Blight, Louise K

    2011-01-01

    Seabirds integrate information about oceanic ecosystems across time and space, and are considered sensitive indicators of marine conditions. To assess whether hypothesized long-term foodweb changes such as forage fish declines may be reflected in a consumer's life history traits over time, I used meta-regression to evaluate multi-decadal changes in aspects of egg production in the glaucous-winged gull (Larus glaucescens), a common coastal bird. Study data were derived from literature searches of published papers and unpublished historical accounts, museum egg collections, and modern field studies, with inclusion criteria based on data quality and geographic area of the original study. Combined historical and modern data showed that gull egg size declined at an average of 0.04 cc y(-1) from 1902 (108 y), equivalent to a decline of 5% of mean egg volume, while clutch size decreased over 48 y from a mean of 2.82 eggs per clutch in 1962 to 2.25 in 2009. There was a negative relationship between lay date and mean clutch size in a given year, with smaller clutches occurring in years where egg laying commenced later. Lay date itself advanced over time, with commencement of laying presently (2008-2010) 7 d later than in previous studies (1959-1986). This study demonstrates that glaucous-winged gull investment in egg production has declined significantly over the past ∼50-100 y, with such changes potentially contributing to recent population declines. Though gulls are generalist feeders that should readily be able to buffer themselves against food web changes, they are likely nutritionally constrained during the early breeding period, when egg production requirements are ideally met by consumption of high-quality prey such as forage fish. This study's results suggest a possible decline in the availability of such prey, and the incremental long-term impoverishment of a coastal marine ecosystem bordering one of North America's rapidly growing urban areas. PMID:21789207

  12. Egg Production in a Coastal Seabird, the Glaucous-Winged Gull (Larus glaucescens), Declines during the Last Century

    PubMed Central

    Blight, Louise K.

    2011-01-01

    Seabirds integrate information about oceanic ecosystems across time and space, and are considered sensitive indicators of marine conditions. To assess whether hypothesized long-term foodweb changes such as forage fish declines may be reflected in a consumer's life history traits over time, I used meta-regression to evaluate multi-decadal changes in aspects of egg production in the glaucous-winged gull (Larus glaucescens), a common coastal bird. Study data were derived from literature searches of published papers and unpublished historical accounts, museum egg collections, and modern field studies, with inclusion criteria based on data quality and geographic area of the original study. Combined historical and modern data showed that gull egg size declined at an average of 0.04 cc y−1 from 1902 (108 y), equivalent to a decline of 5% of mean egg volume, while clutch size decreased over 48 y from a mean of 2.82 eggs per clutch in 1962 to 2.25 in 2009. There was a negative relationship between lay date and mean clutch size in a given year, with smaller clutches occurring in years where egg laying commenced later. Lay date itself advanced over time, with commencement of laying presently (2008–2010) 7 d later than in previous studies (1959–1986). This study demonstrates that glaucous-winged gull investment in egg production has declined significantly over the past ∼50–100 y, with such changes potentially contributing to recent population declines. Though gulls are generalist feeders that should readily be able to buffer themselves against food web changes, they are likely nutritionally constrained during the early breeding period, when egg production requirements are ideally met by consumption of high-quality prey such as forage fish. This study's results suggest a possible decline in the availability of such prey, and the incremental long-term impoverishment of a coastal marine ecosystem bordering one of North America's rapidly growing urban areas. PMID

  13. Multi-laboratory evaluations of the performance of Catellicoccus marimammalium PCR assays developed to target gull fecal sources.

    PubMed

    Sinigalliano, Christopher D; Ervin, Jared S; Van De Werfhorst, Laurie C; Badgley, Brian D; Ballesté, Elisenda; Bartkowiak, Jakob; Boehm, Alexandria B; Byappanahalli, Muruleedhara; Goodwin, Kelly D; Gourmelon, Michèle; Griffith, John; Holden, Patricia A; Jay, Jenny; Layton, Blythe; Lee, Cheonghoon; Lee, Jiyoung; Meijer, Wim G; Noble, Rachel; Raith, Meredith; Ryu, Hodon; Sadowsky, Michael J; Schriewer, Alexander; Wang, Dan; Wanless, David; Whitman, Richard; Wuertz, Stefan; Santo Domingo, Jorge W

    2013-11-15

    Here we report results from a multi-laboratory (n = 11) evaluation of four different PCR methods targeting the 16S rRNA gene of Catellicoccus marimammalium originally developed to detect gull fecal contamination in coastal environments. The methods included a conventional end-point PCR method, a SYBR(®) Green qPCR method, and two TaqMan(®) qPCR methods. Different techniques for data normalization and analysis were tested. Data analysis methods had a pronounced impact on assay sensitivity and specificity calculations. Across-laboratory standardization of metrics including the lower limit of quantification (LLOQ), target detected but not quantifiable (DNQ), and target not detected (ND) significantly improved results compared to results submitted by individual laboratories prior to definition standardization. The unit of measure used for data normalization also had a pronounced effect on measured assay performance. Data normalization to DNA mass improved quantitative method performance as compared to enterococcus normalization. The MST methods tested here were originally designed for gulls but were found in this study to also detect feces from other birds, particularly feces composited from pigeons. Sequencing efforts showed that some pigeon feces from California contained sequences similar to C. marimammalium found in gull feces. These data suggest that the prevalence, geographic scope, and ecology of C. marimammalium in host birds other than gulls require further investigation. This study represents an important first step in the multi-laboratory assessment of these methods and highlights the need to broaden and standardize additional evaluations, including environmentally relevant target concentrations in ambient waters from diverse geographic regions. PMID:23916157

  14. Akpatok Island

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Akpatok Island lies in Ungava Bay in northern Quebec, Canada. Accessible only by air, Akpatok Island rises out of the water as sheer cliffs that soar 500 to 800 feet (150 to 243 m) above the sea surface. The island is an important sanctuary for cliff-nesting seabirds. Numerous ice floes around the island attract walrus and whales, making Akpatok a traditional hunting ground for native Inuit people. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on January 22, 2001. Image provided by the USGS EROS Data Center Satellite Systems Branch

  15. Relationships between environmental organochlorine contaminant residues, plasma corticosterone concentrations, and intermediary metabolic enzyme activities in Great Lakes herring gull embryos.

    PubMed Central

    Lorenzen, A; Moon, T W; Kennedy, S W; Glen, G A

    1999-01-01

    Experiments were conducted to survey and detect differences in plasma corticosterone concentrations and intermediary metabolic enzyme activities in herring gull (Larus argentatus) embryos environmentally exposed to organochlorine contaminants in ovo. Unincubated fertile herring gull eggs were collected from an Atlantic coast control site and various Great Lakes sites in 1997 and artificially incubated in the laboratory. Liver and/or kidney tissues from approximately half of the late-stage embryos were analyzed for the activities of various intermediary metabolic enzymes known to be regulated, at least in part, by corticosteroids. Basal plasma corticosterone concentrations were determined for the remaining embryos. Yolk sacs were collected from each embryo and a subset was analyzed for organochlorine contaminants. Regression analysis of individual yolk sac organochlorine residue concentrations, or 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs), with individual basal plasma corticosterone concentrations indicated statistically significant inverse relationships for polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs), total polychlorinated biphenyls (PCBs), non-ortho PCBs, and TEQs. Similarly, inverse relationships were observed for the activities of two intermediary metabolic enzymes (phosphoenolpyruvate carboxykinase and malic enzyme) when regressed against PCDDs/PCDFs. Overall, these data suggest that current levels of organochlorine contamination may be affecting the hypothalamo-pituitary-adrenal axis and associated intermediary metabolic pathways in environmentally exposed herring gull embryos in the Great Lakes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:10064546

  16. Fine-scale flight strategies of gulls in urban airflows indicate risk and reward in city living.

    PubMed

    Shepard, Emily L C; Williamson, Cara; Windsor, Shane P

    2016-09-26

    Birds modulate their flight paths in relation to regional and global airflows in order to reduce their travel costs. Birds should also respond to fine-scale airflows, although the incidence and value of this remains largely unknown. We resolved the three-dimensional trajectories of gulls flying along a built-up coastline, and used computational fluid dynamic models to examine how gulls reacted to airflows around buildings. Birds systematically altered their flight trajectories with wind conditions to exploit updraughts over features as small as a row of low-rise buildings. This provides the first evidence that human activities can change patterns of space-use in flying birds by altering the profitability of the airscape. At finer scales still, gulls varied their position to select a narrow range of updraught values, rather than exploiting the strongest updraughts available, and their precise positions were consistent with a strategy to increase their velocity control in gusty conditions. Ultimately, strategies such as these could help unmanned aerial vehicles negotiate complex airflows. Overall, airflows around fine-scale features have profound implications for flight control and energy use, and consideration of this could lead to a paradigm-shift in the way ecologists view the urban environment.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'. PMID:27528784

  17. Susceptibility of North American Ducks and Gulls to H5N1 Highly Pathogenic Avian Influenza Viruses

    PubMed Central

    Stallknecht, David E.; Beck, Joan R.; Suarez, David L.; Swayne, David E.

    2006-01-01

    Since 2002, H5N1 highly pathogenic avian influenza (HPAI) viruses have been associated with deaths in numerous wild avian species throughout Eurasia. We assessed the clinical response and extent and duration of viral shedding in 5 species of North American ducks and laughing gulls (Larus atricilla) after intranasal challenge with 2 Asian H5N1 HPAI viruses. Birds were challenged at ≈10 to 16 weeks of age, consistent with temporal peaks in virus prevalence and fall migration. All species were infected, but only wood ducks (Aix sponsa) and laughing gulls exhibited illness or died. Viral titers were higher in oropharyngeal swabs than in cloacal swabs. Duration of viral shedding (1–10 days) increased with severity of clinical disease. Both the hemagglutination-inhibition (HI) and agar gel precipitin (AGP) tests were able to detect postinoculation antibodies in surviving wood ducks and laughing gulls; the HI test was more sensitive than the AGP in the remaining 4 species PMID:17283615

  18. Reproductive success of the Black-crowned Night Heron at Alcatraz Island, San Francisco Bay, California, 1990-2002

    USGS Publications Warehouse

    Hothem, R.L.; Hatch, D.

    2004-01-01

    Nesting chronology, habitat use, subcolony use, and hatchability were documented for the Black-crowned Night Heron (Nycticorax nycticorax) nesting at Alcatraz Island, San Francisco Bav, California during 1990-2002. Reproductive success was estimated using the Mayfield method and compared among years. Totals of monitored nests per year ranged from 68 in 2001 to 341 in 1996, with a trend of declining numbers since 1996. An increase in numbers of the Western Gull (Larus occidentalis), the Black-crowned Night Heron's primary competitor, occurred during the same period. Overall reproductive success of the Black-crowned Night Heron at Alcatraz Island was below the 13-year average of 56.4% since 1996. During the study, the average number of chicks fledged per nest each year ranged from 0.46 to 1.27, which is less than the two chicks per nest suggested as a requirement for a sustained population. Embryos in five of 187 failed Black-crowned Night Heron eggs were deformed. In 1990 and 1991, eggs were analyzed for a wide range of contaminants, but none appeared to be sufficiently elevated to have caused the observed deformities. Based on these relatively low levels of contaminants, a high hatchability rate (94.5%), and relatively low levels of embryotoxicity, contaminants did not appear to significantly affect Black-crowned Night Heron reproduction at Alcatraz Island. However, predation by the Common Raven (Corvus corax) and Western Gull, interspecific competition with the Western Gull, habitat deterioration, and possible human disturbance are likely factors contributing to the decline in Black-crowned Night Heron reproductive success on Alcatraz Island in recent years.

  19. Island Hopping

    ERIC Educational Resources Information Center

    Bennett, Gayle

    2009-01-01

    At some institutions, it may feel as though faculty live on one island and advancement staff on another. The islands form part of an archipelago, and they exchange ambassadors and send emissaries occasionally, but interactions are limited. It may even seem as though the two groups speak different languages, deal in different currencies, and abide…

  20. Pressure-gradient-driven nearshore circulation on a beach influenced by a large inlet-tidal shoal system

    USGS Publications Warehouse

    Shi, F.; Hanes, D.M.; Kirby, J.T.; Erikson, L.; Barnard, P.; Eshleman, J.

    2011-01-01

    The nearshore circulation induced by a focused pattern of surface gravity waves is studied at a beach adjacent to a major inlet with a large ebb tidal shoal. Using a coupled wave and wave-averaged nearshore circulation model, it is found that the nearshore circulation is significantly affected by the heterogeneous wave patterns caused by wave refraction over the ebb tidal shoal. The model is used to predict waves and currents during field experiments conducted near the mouth of San Francisco Bay and nearby Ocean Beach. The field measurements indicate strong spatial variations in current magnitude and direction and in wave height and direction along Ocean Beach and across the ebb tidal shoal. Numerical simulations suggest that wave refraction over the ebb tidal shoal causes wave focusing toward a narrow region at Ocean Beach. Due to the resulting spatial variation in nearshore wave height, wave-induced setup exhibits a strong alongshore nonuniformity, resulting in a dramatic change in the pressure field compared to a simulation with only tidal forcing. The analysis of momentum balances inside the surf zone shows that, under wave conditions with intensive wave focusing, the alongshore pressure gradient associated with alongshore nonuniform wave setup can be a dominant force driving circulation, inducing heterogeneous alongshore currents. Pressure-gradient- forced alongshore currents can exhibit flow reversals and flow convergence or divergence, in contrast to the uniform alongshore currents typically caused by tides or homogeneous waves.

  1. Shoaling of large-amplitude nonlinear internal waves at Dongsha Atoll in the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Fu, Ke-Hsien; Wang, Yu-Huai; St. Laurent, Louis; Simmons, Harper; Wang, Dong-Ping

    2012-04-01

    Shoaling of large-amplitude (˜100 m) nonlinear internal waves over a steep slope (˜3°) in water depths between 100 m and 285 m near Dongsha Atoll in the northern South China Sea is examined with an intensive array of thermistor moorings and a bottom mounted Acoustic Doppler Current Profiler. During the 44 h study period in May 5-7, 2008, there were four groups of large internal waves with semidiurnal modulation. In each wave group a rapid transition occurred during the shoaling, such that the front face of the leading depression wave elongated and plunged to the bottom and the rear face steepened and transformed into a bottom-trapped elevation wave. The transitions occur in water depths of 200 m and deeper, and represent the largest documented internal wave shoaling events. The observations repeatedly capture the detailed temperature and velocity structures of the incident plunging waves. Strong horizontal convergence and intense upward motion are found at the leading edge of transformed elevation waves, suggesting flow separation near the bottom. The observations are compared with the previous observations and model studies. The implication of the shoaling internal waves on coral reef ecology also is discussed.

  2. Winter storm-induced hydrodynamics and morphological response of a shallow transgressive shoal complex: Northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Siadatmousavi, S. Mostafa; Jose, Felix

    2015-03-01

    Using extended deployments during seasons of low and high discharge from the Atchafalaya River, meteorological, hydrodynamic and bottom boundary layer parameters were monitored from Tiger and Trinity Shoal complex, off Louisiana coast, USA. During winter storms, the surface current speed measured at both shoals exceeded 0.5 m/s and the entire water column followed the prevailing wind direction. The current speed close to the bottom exceeded 0.3 m/s during high energy northerly winds. The mean water level in the shoal complex increased during southerly winds and decreased during northerly winds, such that the difference between wind set-up and set-down exceeded 0.7 m in Tiger Shoal and 0.6 m in Trinity Shoal during high energy frontal passages. The swell height was inversely correlated with mean water level, and increased during pre-frontal phase and decreased during post-frontal phase of winter storms. The sea (short waves) height responded quickly to wind direction and speed; and within a few hours after the wind shifted and blowing from the north, the sea height increased during both deployments. Bimodal wave frequency spectrum was observed during wind veering from southerly to northerly, when both sea and swell intensities were significant. The Tiger Shoal bed sediment texture transformed drastically, from mud to shell and shell hash assemblage, within a period of two weeks during the December 2008 deployment. Backscatter signal intensity from a Pulse Coherent Acoustic Doppler Profiler (PCADP) and its velocity estimates were used to determine the vertical extend and timing of mud resuspension and their eventual flushing out from the shoal environment, when exposed to high energy winter storm passages. The computed time frame for a total transformation of bottom sediment texture (from muddy bottom to shell and shell hash assemblage) was supported by the combined wave and bottom current induced shear stress at shoal bed. The bed samples collected from Tiger Shoal

  3. Characteristics and Mechanisms of Cardiopulmonary Injury Caused by Mine Blasts in Shoals: A Randomized Controlled Study in a Rabbit Model

    PubMed Central

    Han, Gengfen; Wang, Ziming; Wang, Jianmin; Yang, Weixiao; Chen, Jing; Kang, Jianyi; Zhang, Sen; Wang, Aimin; Lai, Xinan

    2013-01-01

    Background Because the characteristics of blast waves in water are different from those in air and because kinetic energy is liberated by a pressure wave at the water-air interface, thoracic injuries from mine blasts in shoals may be serious. The aim of the present study was to investigate the characteristics and mechanisms of cardiopulmonary injury caused by mine blasts in shoals. Methods To study the characteristics of cardiopulmonary injury, 56 animals were divided randomly into three experimental groups (12 animals in the sham group, 22 animals in the land group and 22 animals in the shoal group). To examine the biomechanics of injury, 20 animals were divided randomly into the land group and the shoal group. In the experimental model, the water surface was at the level of the rabbit's xiphoid process, and paper electric detonators (600 mg RDX) were used to simulate mines. Electrocardiography and echocardiography were conducted, and arterial blood gases, serum levels of cardiac troponin I and creatine kinase-MB and other physiologic parameters were measured over a 12-hour period after detonation. Pressures in the thorax and abdomen and the acceleration of the thorax were measured. Conclusion The results indicate that severe cardiopulmonary injury and dysfunction occur following exposure to mine blasts in shoals. Therefore, the mechanisms of cardiopulmonary injury may result from shear waves that produce strain at the water-air interface. Another mechanism of injury includes the propagation of the shock wave from the planta to the thorax, which causes a much higher peak overpressure in the abdomen than in the thorax; as a result, the abdominal organs and diaphragm are thrust into the thorax, damaging the lungs and heart. PMID:24358110

  4. 2009 Groundwater Monitoring Report Project Shoal Area, Corrective Action Unit 447

    SciTech Connect

    2010-03-01

    This report presents the 2009 groundwater monitoring results collected by the U.S. Department of Energy (DOE) Office of Legacy Management (LM) at the Project Shoal Area (PSA) Subsurface Corrective Action Unit (CAU) 447 in Churchill County, Nevada. Responsibility for the environmental site restoration of the PSA was transferred from the DOE Office of Environmental Management to LM on October 1, 2006. The environmental restoration process and corrective action strategy for CAU 447 are conducted in accordance with the Federal Facility Agreement and Consent Order (FFACO 1996, as amended February 2008) entered into by DOE, the U.S. Department of Defense, and the State of Nevada. The corrective action strategy for the site includes monitoring in support of site closure. This report summarizes investigation activities associated with CAU 447 that were conducted at the PSA during fiscal year 2009.

  5. 2008 Groundwater Monitoring Report Project Shoal Area, Corrective Action Unit 447

    SciTech Connect

    2009-03-01

    This report presents the 2008 groundwater monitoring results collected by the U.S. Department of Energy (DOE) Office of Legacy Management (LM) at the Project Shoal Area (PSA) Subsurface Corrective Action Unit (CAU) 447 located in Churchill County, Nevada. Responsibility for the environmental site restoration of the PSA was transferred from the DOE Office of Environmental Management to LM on October 1, 2006. The environmental restoration process and corrective action strategy for CAU 447 are conducted in accordance with the Federal Facility Agreement and Consent Order (FFACO 1996, as amended February 2008) entered into by DOE, the U.S. Department of Defense, and the State of Nevada. The corrective action strategy for the site includes proof of concept monitoring in support of site closure. This report summarizes investigation activities associated with CAU 447 that were conducted at the site during 2008. This is the second groundwater monitoring report prepared by LM for the PSA

  6. 2010 Groundwater Monitoring Report Project Shoal Area, Corrective Action Unit 447

    SciTech Connect

    2011-02-01

    This report presents the 2010 groundwater monitoring results collected by the U.S. Department of Energy (DOE) Office of Legacy Management (LM) at the Project Shoal Area (PSA) Subsurface Corrective Action Unit (CAU) 447 in Churchill County, Nevada. Responsibility for the environmental site restoration of the PSA was transferred from the DOE Office of Environmental Management to LM on October 1, 2006. The environmental restoration process and corrective action strategy for CAU 447 are conducted in accordance with the Federal Facility Agreement and Consent Order (FFACO 1996, as amended March 2010) entered into by DOE, the U.S. Department of Defense, and the State of Nevada. The corrective action strategy for the site includes monitoring in support of site closure. This report summarizes the results from the groundwater monitoring program during fiscal year 2010.

  7. Response of shoal grass, Halodule wrightii, to extreme winter conditions in the Lower Laguna Madre, Texas

    USGS Publications Warehouse

    Hicks, D.W.; Onuf, C.P.; Tunnell, J.W.

    1998-01-01

    Effects of a severe freeze on the shoal grass, Halodule wrightii, were documented through analysis of temporal and spatial trends in below-ground biomass. The coincidence of the second lowest temperature (-10.6??C) in 107 years of record, 56 consecutive hours below freezing, high winds and extremely low water levels exposed the Laguna Madre, TX, to the most severe cold stress in over a century. H. wrightii tolerated this extreme freeze event. Annual pre- and post-freeze surveys indicated that below-ground biomass estimated from volume was Unaffected by the freeze event. Nor was there any post-freeze change in biomass among intertidal sites directly exposed to freezing air temperatures relative to subtidal sites which remained submerged during the freezing period.

  8. Groundwater Model Validation for the Project Shoal Area, Corrective Action Unit 447

    SciTech Connect

    2008-05-19

    Stoller has examined newly collected water level data in multiple wells at the Shoal site. On the basis of these data and information presented in the report, we are currently unable to confirm that the model is successfully validated. Most of our concerns regarding the model stem from two findings: (1) measured water level data do not provide clear evidence of a prevailing lateral flow direction; and (2) the groundwater flow system has been and continues to be in a transient state, which contrasts with assumed steady-state conditions in the model. The results of DRI's model validation efforts and observations made regarding water level behavior are discussed in the following sections. A summary of our conclusions and recommendations for a path forward are also provided in this letter report.

  9. Maternal transfer of organohalogen contaminants and metabolites to eggs of Arctic-breeding glaucous gulls.

    PubMed

    Verreault, Jonathan; Villa, Rosa A; Gabrielsen, Geir W; Skaare, Janneche U; Letcher, Robert J

    2006-12-01

    Eggs of seabirds have routinely been used as indicators of environmental pollution in the Arctic. However, the variability in organohalogen concentration and composition associated with the laying sequence, have not been defined. We examined a suite of PCBs, organochlorine (OC) pesticides and by-products, polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs) and methylsulfonyl- (MeSO2) PCBs in complete 3-egg clutches of glaucous gulls (Larus hyperboreus), and plasma samples of the laying females collected from the Norwegian Arctic. SigmaPCB, SigmaOC and SigmaPBDE, but not SigmaMeSO2-PCB, concentrations in eggs were positively associated, with increasing magnitude and significance from the first through the last-laid egg, with concentrations in female plasma. However, the concentrations of these organohalogen classes fluctuated irrespective of the laying order in the clutch. In general, maternal transfer favored low K(ow) and/or less persistent compounds, whereas the recalcitrant and/or higher-halogenated compounds were less readily transferred, and consequently more selectively retained in the mother. PMID:16563578

  10. Reduced oxygen diffusion across the shell of Gray gull (Larus modestus) eggs.

    PubMed

    Monge, C C; Ostojic, H; Aguilar, R; Cifuentes, V

    2000-01-01

    Gray gulls, Larus modestus, nest 1500 m above sea level in northern Chile's Atacama Desert, one of the driest in the world. Their eggshell gas permeability, one third of that found in other Larus species, is an adaptation that reduces water loss, but at the expense of oxygen diffusion into the air cell with resultant hypoxia and reduced metabolic rate. This contrasts with characteristics found in birds nesting at very high altitudes where oxygen diffusion across the egg shell is maximized at the expense of water conservation. The oxygen consumption (MO2) of Larus modestus is 66% that of Larus argentatus; the oxygen conductance (GO2) is equivalent to 48% of that obtained in 5 other bird species. The oxygen partial pressure (PAO2) in the air chamber of Larus modestus (84 Torr) is lower than that of 10 other bird species whose average (PAO2) is 106 Torr. The CO2 partial pressure (PACO2) in the air chamber of Larus modestus is 68 Torr, a higher value than that found in 9 other bird species whose average (PACO2) is 39 Torr. PMID:15696681

  11. Transmission of H5N1 high pathogenicity avian influenza virus to Herring gulls (Larus argentatus) through intranasal inoculation of virus and ingestion of virus-infected chicken meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to evaluate the susceptibility of herring gulls (Larus argentatus) to H5N1 highly pathogenic avian influenza (HPAI) virus under natural routes of infection, we exposed gulls to two Asian lineage H5N1 HPAI viruses (A/whooper swan/Mongolia/244/05 and A/duck meat/Anyang/AVL-1/01) via intranasa...

  12. Structure, age and origin of the bay-mouth shoal deposits, Chesapeake Bay, Virginia

    USGS Publications Warehouse

    Colman, Steven M.; Berquist, C.R., Jr.; Hobbs, C. H., III

    1988-01-01

    The mouth of Chesapeake Bay contains a distinctive shoal complex and related deposits that result from the complex interaction of three different processes: (1) progradation of a barrier spit at the southern end of the Delmarva Peninsula, (2) strong, reversing tidal currents that transport and rework sediment brought to the bay mouth from the north, and (3) landward (bayward) net non-tidal circulation and sediment transport. Together, these processes play a major role in changing the configuration of the estuary and filling it with sediment. The deposits at the mouth of the bay hold keys both to the evolution of the bay during the Holocene transgression and to the history of previous generations of the bay. The deposit associated with the shoals at the mouth of the bay, the bay-mouth sand, is a distinct stratigraphic unit composed mostly of uniform, gray, fine sand. The position and internal structure of the unit shows that it is related to near-present sea level, and thus is less than a few thousand years old. The processes affecting the upper surface of the deposit and the patterns of erosion and deposition at this surface are complex, but the geometry and structure of the deposit indicate that it is a coherent unit that is prograding bayward and tending to fill the estuary. The source of the bay-mouth sand is primarily outside the bay in the nearshore zone of the Delmarva Peninsula and on the inner continental shelf. The internal structure of the deposit, its surface morphology, its heavy-mineral composition, bottom-current studies, comparative bathymetry, and sediment budgets all suggest that sand is brought to the bay mouth by southerly longshore drift along the Delmarva Peninsula and then swept into the bay. In addition to building the southward- and bayward-prograding bay-mouth sand, these processes result in sand deposition tens of kilometers into the bay. ?? 1988.

  13. Possible return of Acropora cervicornis at Pulaski Shoal, Dry Tortugas National Park, Florida

    USGS Publications Warehouse

    Lidz, Barbara H.; Zawada, David G.

    2013-01-01

    Seabed classification is essential to assessing environmental associations and physical status in coral reef ecosystems. At Pulaski Shoal in Dry Tortugas National Park, Florida, nearly continuous underwater-image coverage was acquired in 15.5 hours in 2009 along 70.2 km of transect lines spanning ~0.2 km2. The Along-Track Reef-Imaging System (ATRIS), a boat-based, high-speed, digital imaging system, was used. ATRIS-derived benthic classes were merged with a QuickBird satellite image to create a habitat map that defines areas of senile coral reef, carbonate sand, seagrasses, and coral rubble. This atypical approach of starting with extensive, high-resolution in situ imagery and extrapolating between transect lines using satellite imagery leverages the strengths of each remote-sensing modality. The ATRIS images also captured the spatial distribution of two species once common on now-degraded Florida-Caribbean coral reefs: the stony staghorn coral Acropora cervicornis, a designated threatened species, and the long-spined urchin Diadema antillarum. This article documents the utility of ATRIS imagery for quantifying number and estimating age of A. cervicornis colonies (n = 400, age range, 5–11 y) since the severe hypothermic die-off in the Dry Tortugas in 1976–77. This study is also the first to document the largest number of new colonies of A. cervicornis tabulated in an area of the park where coral-monitoring stations maintained by the Fish and Wildlife Research Institute have not been established. The elevated numbers provide an updated baseline for tracking revival of this species at Pulaski Shoal.

  14. Turbulence and mixing generated by internal waves shoaling on a barrier reef.

    NASA Astrophysics Data System (ADS)

    Davis, K. A.; Monismith, S. G.

    2008-12-01

    Results are presented from an observational study of the turbulent bottom boundary layer on the outer Southeast Florida shelf in July and August 2005. ADCPs and ADVs deployed at 15 m on Conch Reef measured mean and turbulent velocities. Turbulence in the reef bottom boundary layer is highly variable in time and is modified by near bed flow, shear, and stratification driven by shoaling internal waves. In the absence of internal waves on the shelf, currents from 1 to 5 meters above the bed are well described by a logarithmic profile and turbulent dissipation measured 0.6 to 3.0 meters above the bed agrees with classic bottom boundary layer scaling. We examine turbulence in the bottom boundary layer during a typical internal wave event and show that internal waves can induce significant increases in near-bed flow speed, shear, dissipation, and turbulent scalar diffusivity, Kρ. Estimates of flux Richardson number, calculated directly from measurements of dissipation and buoyancy flux, support the dependence of Rf on Frt and on turbulent intensity, ɛ/νN2, relationships that have been previously shown in laboratory and numerical work. Results from this study suggest that for reef communities exposed to continental shelf and slope processes, internal waves may play an important role in mass transfer to benthic organisms. In addition to the episodic onshore transport of cool, subthermocline water masses, with elevated nutrient concentrations, we have shown that the bottom-intensified currents from shoaling internal waves can increase turbulent dissipation and mixing in the reef bottom boundary layer.

  15. Streamlined approach for environmental restoration plan for corrective action unit 416, Mud Pit, Project Shoal Area

    SciTech Connect

    1997-07-01

    This plan addresses the actions necessary for the restoration and closure of the Project Shoal Area (PSA), Surface Corrective Action Unit (CAU) 416, Mud Pit (Corrective Action Site No. 57-09-01), a pit that was used to store effluent produced during drilling of the Post-Shot Borehole PS-1 in 1963. This plan describes the activities that will occur at the site and the steps that will be taken to gather enough data to obtain a notice of completion from the Nevada Division of Environmental Protection (NDEP). This plan was prepared under the Streamlined Approach for Environmental Restoration (SAFER) concept, and it will be implemented with the Federal Facility Agreement and Consent Order (FFACO) (FFACO, 1996) and the Industrial Sites Quality Assurance Project Plan (DOE/NV, 1994). The SAFER process is being employed at this CAU where enough information exists about the nature and extent of contamination to propose an appropriate corrective action without completing a Corrective Action Decision Document and Corrective Action Plan. This process combines elements of the Data Quality Objective (DQO) process and the observational approach to help plan and conduct corrective actions. DQOs are used to identify the problem and define the type and quality of data needed to complete the investigation phase of the process. This has already been completed for the mud pit so it will not be repeated here. The DQOs for the mud pit are presented in the Corrective Action Investigation Plan for Project Shoal Area, CAU No. 416 (DOE/NV, 1996). This observational approach provides a framework for managing uncertainty and planning decision making.

  16. Rebecca shoal barrier reef complex of Gulfian and Paleocene age - onshore and offshore Florida

    SciTech Connect

    Winston, G.O.

    1989-03-01

    Surrounding the Florida Peninsula and the offshore portion of the South Florida basin is a 1300-mi long dolomite barrier reef complex that occupies a 3800-ft composite interval spanning most of the Gulfian and Paleocene. Forty-four wells have penetrated various aspects of this complex. Growth began with the Card Sound facies (some 1400 ft thick) in the lower Gulfian, shortly after the end of the Early Cretaceous. This facies is present in only two wells, 4 mi apart on Key Largo. The appearance of the Rebecca Shoal reef in the earliest Gulfian indicates that the Florida Straits were then present, as deep water would have been necessary to support a growing reef of this magnitude. During the late Gulfian, the reef (Plantation equivalent) expanded northward along the East Coast and westward along the Keys. The width now was over 6 mi. By the beginning of the Paleocene, the reef (Tavernier facies) had completely surrounded the peninsula, resulting in the deposition of the Cedar Keys dolomite-anhydrite lagoonal facies. The width of the complex was now as much as 20 mi. At the close of the Paleocene, the Rebecca Shoals reef ended abruptly. It was overlain by an orange/brown anhedral dolomite characteristic of the basal Eocene. The lithology of the outer region of the reef complex is characterized by a light-colored, porous, fine to medium crystalline euhedral dolomite. Large cavities, including a 60-ft cavern, have been reported. Two core samples show a taluslike rubble texture with vug porosity between the square-sided fragments. Behind the Tavernier reef, this facies is gradually replaced by nonporous anhedral and cryptocrystalline dolomite. Farther lagoonward, these three lithologies become interbedded with typical Cedar keys, a very fine microcrystalline to microcrystalline dolomite.

  17. Fluid Management Plan for Corrective Action Unit 447: Project Shoal Area, Subsurface, Nevada, Rev. No.: 1

    SciTech Connect

    Findlay, Rick

    2006-01-01

    The U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) initiated the Offsites Project to characterize the risk posed to human health and the environment as a result of testing at formerly used nuclear sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The scope of this Fluid Management Plan (FMP) is to support the subsurface investigation at the Project Shoal Area (PSA) Corrective Action Unit (CAU) 447, Shoal - Subsurface, Nevada, in accordance with the ''Federal Facility Agreement and Consent Order'' (FFACO) (1996). Corrective Action Unit 447 is located in the Sand Spring Range, south of Highway 50, about 39 miles southeast of Fallon, Nevada. (Figure 1-1). This FMP will be used at the PSA in lieu of an individual discharge permit for each well or a general water pollution control permit for management of all fluids produced during the drilling, construction, development, testing, experimentation, and/or sampling of wells conducted by the Offsites Project. The FMP provides guidance for the management of fluids generated during investigation activities and provides the standards by which fluids may be discharged on site. Although the Nevada Division of Environmental Protection (NDEP), Bureau of Federal Facilities (BoFF) is not a signatory to this FMP, it is involved in the negotiation of the contents of this plan and approves the conditions contained within. The major elements of this FMP include: (1) establishment of a well-site operations strategy; (2) site design/layout; (3) monitoring of contamination indicators (monitoring program); (4) sump characterization (sump sampling program); (5) fluid management decision criteria and fluid disposition; and (6) reporting requirements.

  18. Comparison of lake trout-egg survival at inshore and offshore and shallow-water and deepwater sites in Lake Superior

    USGS Publications Warehouse

    Eshenroder, Randy L.; Bronte, Charles R.; Peck, James W.

    1995-01-01

    We incubated lake trout (Salvelinus namaycush) eggs over winter at shallow (10 m) and deep locations (20 m) on Gull Island Shoal, Lake Superior; at a shallow-water (10 m) site off the mainland (Bark Point); and in flowing Great Lakes water at two laboratories. Survival to hatch was significantly higher in the laboratories and averaged 80.9%. In Lake Superior, egg survival among incubators at all sites was significantly higher (P < 0.0001) for incubators that remained buried in spawning substrates (15.1–21.0%) than for incubators that were partially or completely exposed to water currents (1.0–12.6%). Egg survival for incubators that remained buried at the shallow-water sites was significantly higher at Bark Point (44.6%) than at Gull Island Shoal (21.0%). Egg survival among incubators that remained buried at the deep (14.4%) and shallow-water sites (21.0%) on Gull Island Shoal was not significantly different. Because incubators that were completely buried or partially exposed only appeared to differ in their degree of exposure, we concluded that survival of eggs in the lake was reduced by mechanical stress associated with water turbulence. Lower egg survival at Gull Island Shoal, a known lake trout-spawning site, was not expected and appeared to have been caused by a strong gale that occurred when these eggs were in late epiboly, a sensitive embryological stage. We present a hypothesis suggesting that lake trout recruitment in the Great Lakes is limited by availability of spawning habitat.

  19. Siberian Islands

    Atmospheric Science Data Center

    2013-04-16

    ... Distinguishing Clouds from Ice over the East Siberian Sea, Russia     View Larger Image ... clouds from snow and ice. The central portion of Russia's East Siberian Sea, including one of the New Siberian Islands, Novaya ...

  20. A transactional analysis of changes in parent and chick behaviour prior to separation of Herring Gulls (Larus Argentatus): A three-term contingency model.

    PubMed

    Reed, Phil

    2015-09-01

    The effect of the passage of time on parent-offspring behaviour of urban Herring Gulls (Larus Argentatus) was studied and analysed using a three-term contingency model. A behavioural sequence was initiated by the arrival of a parental adult gull, which would lead to feeding in the chick. However, with the passage of time, and approach of the separation period, this pattern changed. Chicks' begging became more intense, and parent gulls more often withheld food. However, the chicks' begging became directed at a wider range of adults over the observation period. These activities are placed within a three-term contingency model, which may have implications for understanding some behavioural processes involved in parent-offspring separation. PMID:26003136

  1. Island of Okinawa, Japan

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The island of Okinawa, (26.5N, 128.0E) largest of the Ryukyu Islands, Japan. The Ryukyu island group lies south of the main home islands of Japan in an arc towards the Chinese island Republic of Taiwan. As is typical throughout the Japanese home islands, intense urban development can be observed all over the island in this near vertical view.

  2. In Vitro Metabolism of Photolytic Breakdown Products of Tetradecabromo-1,4-diphenoxybenzene Flame Retardant in Herring Gull and Rat Liver Microsomal Assays.

    PubMed

    Su, Guanyong; Greaves, Alana K; Teclechiel, Daniel; Letcher, Robert J

    2016-08-01

    Tetradecabromo-1,4-diphenoxybenzene (TeDB-DiPhOBz) is used as a flame retardant chemical and has been hypothesized to be the precursor of methoxylated polybrominated diphenoxybenzene (MeO-PB-DiPhOBz) contaminants reported in herring gulls from sites across the Laurentian Great Lakes. Here, by irradiating the parent TeDB-DiPhOBz (solution 1) with natural sunlight or UV, we prepared three solutions where solution 2 was dominated by the Br8-11-PB-DiPhOBzs, along with Br5-8-PB-DiPhOBzs (solution 3) and Br4-6-PB-DiPhOBzs (solution 4). The in vitro metabolism of TeDB-DiPhOBz and PB-DiPhOBzs was investigated using harvested wild herring gull (Larus argentatus) and adult male Wister-Han rat liver microsomal assays. After a 90 min incubation period of solution 1 in gull or rat microsomal assays, there was no significant (p > 0.05) depletion of TeDB-DiPhOBz. OH-PB-DiPhOBz metabolites were detectable after gull and rat microsomal assay incubation with solutions 3 or 4, and showed clear species-specific differences. Also detected were two polybrominated hydroxylated metabolites having polybenzofuran structures. Overall, this study suggested that TeDB-DiPhOBz is slowly metabolized in vitro, and also indicated that if wild herring gulls are exposed (e.g., via the diet) to photolytic products of TeDB-DiPhOBz, OH-PB-DiPhOBz and other metabolites could be formed. OH-PH-DiPhOBz are likely precursors to MeO-PB-DiPhOBz contaminants that we reported previously in eggs of wild Great Lakes herring gulls. PMID:27351066

  3. Poplar Island Environmental Restoration Project: Challenges in waterbird restoration on an island in Chesapeake Bay

    USGS Publications Warehouse

    Erwin, R.M.; Miller, J.; Reese, J.G.

    2007-01-01

    At 460 hectares, the Paul Sarbanes Environmental Restoration Project at Poplar Island, Talbot County, Maryland, represents the largest 'beneficial use' dredged material project of the U. S. Army Corps of Engineers (a cooperative project with Maryland Port Administration). Begun in 1998, the 15-year restoration project will ultimately consist of roughly 220 ha of uplands and 220 ha of tidal wetland habitats, with limited areas of dike roads, perimeter riprap, and unvegetated mudflats. Wetland restoration began in one small section (or 'cell') in 2002, but not all cells will be filled with dredged material until at least 2013. As a major objective of the restoration, six species of waterbirds were identified as 'priority species' for Chesapeake Bay: American black duck (Anas rubripes), snowy egret (Egretta thula), cattle egret (Bubulcus ibis), osprey (Pandion haliaetus), common tern (Sterna hirundo), and least tern (S. antillarum). Monitoring of nesting activities of these species from 2002 to 2005 indicated that all species except black ducks colonized the site rapidly. More than 800 pairs of common terns nested in 2003 to 2004. Because of predation by red fox (Vulpes vulpes) and great horned owl (Bubo virginianus), reproductive success was very low for the terns. Trapping was effective in removing the foxes, and other controls have been applied to opportunistic nesting species including herring gulls (Larus argentatus) and Canada geese (Branta canadensis). An effective public education program on the island has helped address concerns about animal control.

  4. Recurrent hybridization and recent origin obscure phylogenetic relationships within the 'white-headed' gull (Larus sp.) complex.

    PubMed

    Sonsthagen, Sarah A; Wilson, Robert E; Chesser, R Terry; Pons, Jean-Marc; Crochet, Pierre-Andre; Driskell, Amy; Dove, Carla

    2016-10-01

    Species complexes that have undergone recent radiations are often characterized by extensive allele sharing due to recent ancestry and (or) introgressive hybridization. This can result in discordant evolutionary histories of genes and heterogeneous genomes, making delineating species limits difficult. Here we examine the phylogenetic relationships among a complex group of birds, the white-headed gulls (Aves: Laridae), which offer a unique window into the speciation process due to their recent evolutionary history and propensity to hybridize. Relationships were examined among 17 species (61 populations) using a multilocus approach, including mitochondrial and nuclear intron DNA sequences and microsatellite genotype information. Analyses of microsatellite and intron data resulted in some species-based groupings, although most species were not represented by a single cluster. Considerable allele and haplotype sharing among white-headed gull species was observed; no locus contained a species-specific clade. Despite this, our multilocus approach provided better resolution among some species than previous studies. Interestingly, most clades appear to correspond to geographic locality: our BEAST analysis recovered strong support for a northern European/Icelandic clade, a southern European/Russian clade, and a western North American/canus clade, with weak evidence for a high latitude clade spanning North America and northwestern Europe. This geographical structuring is concordant with behavioral observations of pervasive hybridization in areas of secondary contact. The extent of allele and haplotype sharing indicates that ecological and sexual selection are likely not strong enough to complete reproductive isolation within several species in the white-headed gull complex. This suggests that just a few genes are driving the speciation process. PMID:27369453

  5. Gene expression, glutathione status and indicators of hepatic oxidative stress in laughing gull (Larus atricilla) hatchlings exposed to methylmercury

    USGS Publications Warehouse

    Jenko, Kathryn; Karouna-Renier, Natalie K.; Hoffman, David J.

    2012-01-01

    Despite extensive studies of methylmercury (MeHg) toxicity in birds, molecular effects on birds are poorly characterized. To improve our understanding of toxicity pathways and identify novel indicators of avian exposure to Hg, the authors investigated genomic changes, glutathione status, and oxidative status indicators in liver from laughing gull (Larus atricilla) hatchlings that were exposed in ovo to MeHg (0.05–1.6 µg/g). Genes involved in the transsulfuration pathway, iron transport and storage, thyroid-hormone related processes, and cellular respiration were identified by suppression subtractive hybridization as differentially expressed. Quantitative polymerase chain reaction (qPCR) identified statistically significant effects of Hg on cytochrome C oxidase subunits I and II, transferrin, and methionine adenosyltransferase RNA expression. Glutathione-S-transferase activity and protein-bound sulfhydryl levels decreased, whereas glucose-6-phosphate dehydrogenase activity increased dose-dependently. Total sulfhydryl concentrations were significantly lower at 0.4 µg/g Hg than in controls. T ogether, these endpoints provided some evidence of compensatory effects, but little indication of oxidative damage at the tested doses, and suggest that sequestration of Hg through various pathways may be important for minimizing toxicity in laughing gulls. This is the first study to describe the genomic response of an avian species to Hg. Laughing gulls are among the less sensitive avian species with regard to Hg toxicity, and their ability to prevent hepatic oxidative stress may be important for surviving levels of MeHg exposures at which other species succumb.

  6. Description of Maritrema formicae sp. nov. (Digenea, Microphallidae) parasitic in the kelp gull, Larus dominicanus, from the Patagonian coast, Argentina.

    PubMed

    Diaz, Julia I; Gilardoni, Carmen; Cremonte, Florencia

    2012-06-01

    Maritrema formicae sp. nov. is described from the Patagonian coast, Argentina, based on adults obtained from the kelp gull, Larus dominicanus. The new species fits with the "eroliae complex" and can be distinguished from other related species mainly in shape and size of body, shape, size, and pattern of distribution of cirrus spines, uterus extension, number and size of eggs, vitellarium in a complete ring in all specimens, and its Neotropical distribution. The new species is sympatric with another species of the genus, Maritrema madrynense, which was recorded in the same host and locality. PMID:22807050

  7. Consistent nonlinear deterministic and stochastic evolution equations for deep to shallow water wave shoaling

    NASA Astrophysics Data System (ADS)

    Vrecica, Teodor; Toledo, Yaron

    2015-04-01

    One-dimensional deterministic and stochastic evolution equations are derived for the dispersive nonlinear waves while taking dissipation of energy into account. The deterministic nonlinear evolution equations are formulated using operational calculus by following the approach of Bredmose et al. (2005). Their formulation is extended to include the linear and nonlinear effects of wave dissipation due to friction and breaking. The resulting equation set describes the linear evolution of the velocity potential for each wave harmonic coupled by quadratic nonlinear terms. These terms describe the nonlinear interactions between triads of waves, which represent the leading-order nonlinear effects in the near-shore region. The equations are translated to the amplitudes of the surface elevation by using the approach of Agnon and Sheremet (1997) with the correction of Eldeberky and Madsen (1999). The only current possibility for calculating the surface gravity wave field over large domains is by using stochastic wave evolution models. Hence, the above deterministic model is formulated as a stochastic one using the method of Agnon and Sheremet (1997) with two types of stochastic closure relations (Benney and Saffman's, 1966, and Hollway's, 1980). These formulations cannot be applied to the common wave forecasting models without further manipulation, as they include a non-local wave shoaling coefficients (i.e., ones that require integration along the wave rays). Therefore, a localization method was applied (see Stiassnie and Drimer, 2006, and Toledo and Agnon, 2012). This process essentially extracts the local terms that constitute the mean nonlinear energy transfer while discarding the remaining oscillatory terms, which transfer energy back and forth. One of the main findings of this work is the understanding that the approximated non-local coefficients behave in two essentially different manners. In intermediate water depths these coefficients indeed consist of rapidly

  8. 2014 Well Completion Report for Corrective Action Unit 447 Project Shoal Area Churchill County, Nevada October 2015

    SciTech Connect

    Findlay, Rick

    2015-11-01

    This report summarizes the drilling program conducted by the U.S. Department of Energy (DOE) Office of Legacy Management at the Project Shoal Area (Shoal) Subsurface Corrective Action Unit 447 in Churchill County, Nevada. Shoal was the location of an underground nuclear test conducted on October 26, 1963, as part of the Vela Uniform program sponsored jointly by the U.S. Department of Defense and the U.S. Atomic Energy Commission (a predecessor to DOE). The test consisted of detonating a 12-kiloton nuclear device in granitic rock at a depth of approximately 1,211 feet (ft) below ground surface (bgs) (AEC 1964). The corrective action strategy for the site is focused on revising the site conceptual model and evaluating the adequacy of the monitoring well network at the site. Field activities associated with the project were conducted in accordance with the Federal Facility Agreement and Consent Order (FFACO 1996, as amended) and applicable Nevada Division of Environmental Protection (NDEP) policies and regulations.

  9. Shoaling and mate choice of wild-type Tanichthys albonubes in the presence of the red fluorescent transgenic conspecifics.

    PubMed

    Jiang, P; Bai, J J; Ye, X; Jian, Q; Chen, M; Chen, X Q

    2011-01-01

    Shoaling and sexual behaviour of wild-type male and female white cloud mountain minnow Tanichthys albonubes were measured in the presence of the red fluorescent transgenic conspecifics under laboratory conditions. Wild-type female test fish showed no significant preference, whereas wild-type male test fish preferred to be near a shoal of red transgenic fish rather than wild-type fish. When placed in a potentially reproductive context, wild-type males had a higher competitive ability over transgenic males; wild-type females spent more time with wild-type males in visually mediated experiments, but wild-type males performed more courtship displays towards transgenic females. These results suggest that the red body colouration does not appear to disturb signal communication between wild-type and transgenic T. albonubes in shoaling behaviour; transgenic males have no mating advantage over wild-type males, but the red body colouration of transgenic females may affect mate choice of wild-type males. PMID:21235550

  10. Bathymetry of the Wilderness breach at Fire Island, New York, June 2013

    USGS Publications Warehouse

    Brownell, Andrew T.; Hapke, Cheryl J.; Spore, Nicholas J.; McNinch, Jesse E.

    2015-01-01

    The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida, collaborated with the U.S. Army Corps of Engineers Field Research Facility in Duck, North Carolina, to collect shallow water bathymetric data of the Wilderness breach on Fire Island, New York, in June 2013. The breach formed in October 2012 during Hurricane Sandy, and the USGS is involved in a post-Sandy effort to map, monitor, and model the morphologic evolution of the breach as part of Hurricane Sandy Supplemental Project GS2-2B: Linking Coastal Vulnerability and Process, Fire Island. This publication includes a bathymetric dataset of the breach and the adjacent nearshore on the ocean side of the island. The objective of the data collection and analysis is to map the bathymetry of the primary breach channel, ebb shoal, and nearshore bar system.

  11. Effect of reduced food intake on toxicokinetics of halogenated organic contaminants in herring gull (Larus argentatus) chicks.

    PubMed

    Routti, Heli; Helgason, Lisa Bjørnsdatter; Arukwe, Augustine; Wolkers, Hans; Heimstad, Eldbjørg Sofie; Harju, Mikael; Berg, Vidar; Gabrielsen, Geir Wing

    2013-01-01

    The aim of the present study was to investigate how contaminant exposure and reduced food intake affect tissue distribution and biotransformation of halogenated organic contaminants (HOCs) in Arctic seabirds using herring gull (Larus argentatus) as a model species. Herring gull chicks were exposed for 44 d to cod liver oil containing a typical mixture of contaminants. Following exposure, food intake was reduced for a one-week period in a subgroup of the chicks. Polyclorinated biphenyls, organochlorine pesticides, and brominated flame retardants, as well as a wide range of hydroxy, methyl sulfone, and methoxy compounds were measured in liver, brain, and plasma samples. Additionally, phase I biotransformation enzyme activities and phase I and II messenger ribonucleic acid (mRNA) expression were investigated in the liver, brain, or both. Both contaminant exposure and reduced food intake had an increasing effect on the concentrations of HOCs and their metabolites. The HOC exposure and reduced food intake also led to increased 7-ethoxyresorufin-O-deethylation (EROD) activity, whereas mRNA expression of the biotransformation enzymes increased only following the reduced food intake. Tissue distribution of HOCs and their metabolites was not affected by either contaminant exposure or reduced food intake. In conclusion, the results indicate that biotransformation capacity and formation of HOC metabolites increase during reduced food intake. This finding supports the hypothesis that reduced food intake increases the susceptibility of Arctic animals to the effects of lipophilic HOCs. PMID:23060285

  12. Genetic structure, diversity and subspecies status of Gull-billed Terns (Gelochelidon nilotica) from the United States

    USGS Publications Warehouse

    Miller, Mark P.; Mullins, Thomas D.; Haig, Susan M.

    2013-01-01

    Gull-billed Terns (Gelochelidon nilotica) are among the most widespread, yet scarce, Charadriiformes in the world. Two subspecies are recognized in the United States: G. n. aranea breeds along the U.S. Atlantic and Gulf coasts and G. n. vanrossemi breeds in the Salton Sea and San Diego Bay of California. Conservation concerns exist for the species due to its low abundance in the United States and apparent declines in some parts of its North American range. We used nuclear microsatellite markers and mitochondrial DNA sequences to assess genetic diversity and differentiation patterns among Gull-billed Tern populations from Virginia, Texas, and California. We also tested for evidence of population bottlenecks, and evaluated the support our data provide for the North American subspecies. Genetic diversity was highest in Texas and underscored the importance of habitat in that large population. Significant population differentiation existed, but could not be consistently identified using various analytical approaches and suggested that the magnitude of differentiation was low. No evidence for bottlenecks was identified. Our data could not distinguish individuals from different subspecies and therefore do not support the current intraspecific taxonomy. Tenable explanations for many findings are related to the low site tenacity demonstrated by the species.

  13. Variation in Immune Parameters and Disease Prevalence among Lesser Black-Backed Gulls (Larus fuscus sp.) with Different Migratory Strategies

    PubMed Central

    Arriero, Elena; Müller, Inge; Juvaste, Risto; Martínez, Francisco Javier; Bertolero, Albert

    2015-01-01

    The ability to control infections is a key trait for migrants that must be balanced against other costly features of the migratory life. In this study we explored the links between migration and disease ecology by examining natural variation in parasite exposure and immunity in several populations of Lesser Black-backed Gulls (Larus fuscus) with different migratory strategies. We found higher activity of natural antibodies in long distance migrants from the nominate subspecies L.f.fuscus. Circulating levels of IgY showed large variation at the population level, while immune parameters associated with antimicrobial activity showed extensive variation at the individual level irrespective of population or migratory strategy. Pathogen prevalence showed large geographical variation. However, the seroprevalence of one of the gull-specific subtypes of avian influenza (H16) was associated to the migratory strategy, with lower prevalence among the long-distance migrants, suggesting that migration may play a role in disease dynamics of certain pathogens at the population level. PMID:25679797

  14. Immunological and reproductive health assessment in herring gulls and black-crowned night herons in the Hudson–Raritan Estuary and Black-Crowned Night Herons in the Hudson-Raritan Estuary

    USGS Publications Warehouse

    Grasman, Keith A.; Echols, Kathy R.; May, Thomas M.; Peterman, Paul H.; Gale, Robert W.; Orazio, Carl E.

    2013-01-01

    Previous studies have shown inexplicable declines in breeding waterbirds within western New York/New Jersey Harbor between 1996 and 2002 and elevated polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls (PCBs) in double-crested cormorant (Phalacrocorax auritus) eggs. The present study assessed associations between immune function, prefledgling survival, and selected organochlorine compounds and metals in herring gulls (Larus argentatus) and black-crowned night herons (Nycticorax nycticorax) in lower New York Harbor during 2003. In pipping gull embryos, lymphoid cells were counted in the thymus and bursa of Fabricius (sites of T and B lymphocyte maturation, respectively). The phytohemagglutinin (PHA) skin response assessed T cell function in gull and heron chicks. Lymphocyte proliferation was measured in vitro in adult and prefledgling gulls. Reference data came from the Great Lakes and Bay of Fundy. Survival of prefledgling gulls was poor, with only 0.68 and 0.5 chicks per nest surviving to three and four weeks after hatch, respectively. Developing lymphoid cells were reduced 51% in the thymus and 42% in the bursa of gull embryos from New York Harbor. In vitro lymphocyte assays demonstrated reduced spontaneous proliferation, reduced T cell mitogen-induced proliferation, and increased B cell mitogen-induced proliferation in gull chicks from New York Harbor. The PHA skin response was suppressed 70 to 80% in gull and heron chicks. Strong negative correlations (r = –0.95 to –0.98) between the PHA response and dioxins and PCBs in gull livers was strong evidence suggesting that these chemicals contribute significantly to immunosuppression in New York Harbor waterbirds.

  15. Devon Island

    Atmospheric Science Data Center

    2013-04-17

    article title:  Mars Researchers Rendezvous on Remote Arctic Island   ... equipment and technology that may be deployed during a human mission to Mars. One of the many objectives of the project scientists is to ... Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed by NASA's ...

  16. Hawaiian Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Multiangle Imaging Spectro-Radiometer (MISR) image of five Hawaiian Islands was acquired by the instrument's vertical- viewing (nadir) camera on June 3, 2000. The image shows the islands of Oahu, Molokai, Lanai, Maui, and Kahoolawe. The prevailing Pacific trade winds bring higher levels of rainfall to the eastern slopes of the islands, leading to a greater abundance of vegetation on the windward coasts. The small change in observation angle across the nadir camera's field-of- view causes the right-hand portion of the image to be more affected by Sun glint, making the ocean surface appear brighter. Oahu is the westernmost of the islands seen in this image. Waikiki Beach and the city of Honolulu are located on the southern shore, to the west of Diamond Head caldera. MISR is one of several Earth-observing instruments on the Terra satellite, launched in December 1999. The Terra spacecraft, the flagship of a fleet of satellites dedicated to understanding our global environment, is part of NASA's Earth Sciences Enterprise, a long-term research program dedicated to understanding how human-induced and natural changes affect our world. Image courtesy NASA/GSFC/JPL, MISR Team

  17. Anatahan Island

    Atmospheric Science Data Center

    2013-04-19

    ... Snorkelers around this island are likely to encounter the fish Achilles Tang and the Moorish Idol (Acanthurus achilles and Zanclus ... Terra circles the Earth in the same orbit as Landsat 7, flying at an altitude of about 700 kilometers above the Earth's surface. ...

  18. Estuary and barrier island study

    NASA Technical Reports Server (NTRS)

    Berg, D. W. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Scan line distortion is apparent in ERTS-1 imagery, imparting a serrated-edge appearance to shorelines. This feature however does not hinder observation and interpretation of broad features such as shoaling areas and sediment plumes. Shoaling in the backshore areas and inlets is easily discernible in spectral bands 4 and 5. Contrast between land and water is especially striking in spectral band 7, allowing easy identification of tidal flat areas.

  19. Using an Automated 3D-tracking System to Record Individual and Shoals of Adult Zebrafish

    PubMed Central

    Maaswinkel, Hans; Zhu, Liqun; Weng, Wei

    2013-01-01

    Like many aquatic animals, zebrafish (Danio rerio) moves in a 3D space. It is thus preferable to use a 3D recording system to study its behavior. The presented automatic video tracking system accomplishes this by using a mirror system and a calibration procedure that corrects for the considerable error introduced by the transition of light from water to air. With this system it is possible to record both single and groups of adult zebrafish. Before use, the system has to be calibrated. The system consists of three modules: Recording, Path Reconstruction, and Data Processing. The step-by-step protocols for calibration and using the three modules are presented. Depending on the experimental setup, the system can be used for testing neophobia, white aversion, social cohesion, motor impairments, novel object exploration etc. It is especially promising as a first-step tool to study the effects of drugs or mutations on basic behavioral patterns. The system provides information about vertical and horizontal distribution of the zebrafish, about the xyz-components of kinematic parameters (such as locomotion, velocity, acceleration, and turning angle) and it provides the data necessary to calculate parameters for social cohesions when testing shoals. PMID:24336189

  20. Design considerations for achieving high accuracy with the SHOALS bathymetric lidar system

    NASA Astrophysics Data System (ADS)

    Guenther, Gary C.; Thomas, Robert W. L.; LaRocque, Paul E.

    1996-11-01

    The ultimate accuracy of depths from an airborne laser hydrography system depends both on careful hardware design aimed at producing the best possible accuracy and precision of recorded data, along with insensitivity to environmental effects, and on post-flight data processing software which corrects for a number of unavoidable biases and provides for flexible operator interaction to handle special cases. The generic procedure for obtaining a depth from an airborne lidar pulse involves measurement of the time between the surface return and the bottom return. In practice, because both of these return times are biased due to a number of environmental and hardware effects, it is necessary to apply various correctors in order to obtain depth estimates which are sufficiently accurate to meet International Hydrographic Office standards. Potential false targets, also of both environmental and hardware origin, must be discriminated, and wave heights must be removed. It is important to have a depth confidence value matched to accuracy and to have warnings about or automatic deletion of pulses with questionable characteristics. Techniques, procedures, and algorithms developed for the SHOALS systems are detailed here.

  1. Development of a Groundwater Management Model for the Project Shoal Area

    SciTech Connect

    G. Lamorey; S. Bassett; R. Schumer; D. Boyle; G. Pohll; J. Chapman

    2006-09-01

    This document describes the development of a user-friendly and efficient groundwater management model of the Project Shoal Area (PSA and surrounding area that will allow the U.S. Department of Energy and State of Nevada personnel to evaluate the impact of proposed water-use scenarios. The management model consists of a simple hydrologic model within an interactive groundwater management framework. This framework is based on an object user interface that was developed by the U.S. Geological Survey and has been used by the Desert Research Institute researchers and others to couple disparate environmental resource models, manage temporal and spatial data, and evaluate model results for management decision making. This framework was modified and applied to the PSA and surrounding Fairview Basin. The utility of the management model was demonstrated through the application of hypothetical future scenarios including mineral mining, regional expansion of agriculture, and export of water to large urban areas outside the region. While the results from some of the scenarios indicated potential impacts to groundwater levels near the PSA and others did not, together they demonstrate the utility of the management tool for the evaluation of proposed changes in groundwater use in or near the PSA.

  2. Growth, bioluminescence and shoal behavior hormetic responses to inorganic and/or organic chemicals: a review.

    PubMed

    Hashmi, Muhammad Zaffar; Naveedullah; Shen, Hui; Zhu, Shenhai; Yu, Chunna; Shen, Chaofeng

    2014-03-01

    A biphasic dose response, termed hormesis, is characterized by beneficial effects of a chemical at a low dose and harmful effects at a high dose. This biphasic dose response phenomenon has the potential to strongly alter toxicology in a broad range. The present review focuses on the progress of research into hormetic responses in terms of growth (in plants, birds, algae and humans), bioluminescence, and shoal behavior as end points. The paper describes how both inorganic and organic chemicals at a low dose show stimulatory responses while at higher doses are inhibitory. The article highlights how factors such as symbiosis, density-dependent factors, time, and contrasting environmental factors (availability of nutrients, temperature, light, etc.) affect both the range and amplitude of hormetic responses. Furthermore, the possible underlying mechanisms are also discussed and we suggest that, for every end point, different hormetic mechanisms may exist. The occurrences of varying interacting receptor systems or receptor systems affecting the assessment of hormesis for each endpoint are discussed. The present review suggests that a hormetic model should be adopted for toxicological evaluations instead of the older threshold and linear non-threshold models. PMID:24361513

  3. Zebrafish response to robotic fish: preference experiments on isolated individuals and small shoals.

    PubMed

    Polverino, G; Abaid, N; Kopman, V; Macrì, S; Porfiri, M

    2012-09-01

    Recently developed bioinspired robots imitate their live counterparts in both aspect and functionality. Nevertheless, whether these devices can be integrated within the ecological niche inspiring their design is seldom tested experimentally. An elemental research question concerns the feasibility of modulating spontaneous behaviour of animal systems through bioinspired robotics. The following study explores the possibility of engineering a robotic fish capable of influencing the behaviour of live zebrafish (Danio rerio) in a dichotomous preference test. While we observe that the preference for the robotic fish never exceeds the preference for a conspecific, our data show that the robot is successful in attracting both isolated individuals and small shoals and that such capability is influenced by its bioinspired features. In particular, we find that the robot's undulations enhance its degree of attractiveness, despite the noise inherent in the actuation system. This is the first experimental evidence that live zebrafish behaviour can be influenced by engineered robots. Such robotic platforms may constitute a valuable tool to investigate the bases of social behaviour and uncover the fundamental determinants of animal functions and dysfunctions. PMID:22677608

  4. Measurements of Reactive Iodine Species on the Isles of Shoals, Gulf of Maine

    NASA Astrophysics Data System (ADS)

    Pikelnaya, O.; Hurlock, S. C.; Trick, S.; Stutz, J.

    2005-12-01

    The chemistry of reactive iodine species has received considerable attention in the past five years. The presence of iodine oxides in the marine boundary layer (MBL) can influence ozone levels, either through well-known catalytic destruction cycles, or through its influence on NO/NO2 and OH/HO2 ratios. In addition, iodine oxides have been linked to aerosol nucleation events in the MBL. Currently, the observational database on reactive iodine species is limited to a very few geographical locations, and the levels of reactive iodine compounds along the North American coast are currently unknown. This lack of information severely restricts our ability to assess the significance of iodine chemistry on a global scale. Here we present the first observations of IO, OIO, and I2 on the Isles of Shoals, Gulf of Maine, during ICARTT 2004, using simultaneous measurements by long-path (LP) and a multi-axis (MAX) differential optical absorption spectroscopy (DOAS) systems.. Both instruments clearly identified reactive iodine species. IO mixing ratios reached 7ppt on several days. OIO was observed during the day, while I2 was elevated at night. Our observations will be discussed with respect to the current knowledge of iodine chemistry, possible iodine sources, and the influence of iodine chemistry on ozone concentrations and aerosol nucleation. Prospects for deriving spatial distributions of reactive iodine species will also be discussed.

  5. Long-Term Effect of Serial Infections with H13 and H16 Low-Pathogenic Avian Influenza Viruses in Black-Headed Gulls

    PubMed Central

    Verhagen, Josanne H.; van Amerongen, Geert; van de Bildt, Marco; Majoor, Frank; Fouchier, Ron A. M.

    2015-01-01

    ABSTRACT Infections of domestic and wild birds with low-pathogenic avian influenza viruses (LPAIVs) have been associated with protective immunity to subsequent infection. However, the degree and duration of immunity in wild birds from previous LPAIV infection, by the same or a different subtype, are poorly understood. Therefore, we inoculated H13N2 (A/black-headed gull/Netherlands/7/2009) and H16N3 (A/black-headed gull/Netherlands/26/2009) LPAIVs into black-headed gulls (Chroicocephalus ridibundus), their natural host species, and measured the long-term immune response and protection against one or two reinfections over a period of >1 year. This is the typical interval between LPAIV epizootics in wild birds. Reinfection with the same virus resulted in progressively less virus excretion, with complete abrogation of virus excretion after two infections for H13 but not H16. However, reinfection with the other virus affected neither the level nor duration of virus excretion. Virus excretion by immunologically naive birds did not differ in total levels of excreted H13 or H16 virus between first- and second-year birds, but the duration of H13 excretion was shorter for second-year birds. Furthermore, serum antibody levels did not correlate with protection against LPAIV infection. LPAIV-infected gulls showed no clinical signs of disease. These results imply that the epidemiological cycles of H13 and H16 in black-headed gulls are relatively independent from each other and depend mainly on infection of first-year birds. IMPORTANCE Low-pathogenic avian influenza viruses (LPAIVs) circulate mainly in wild water birds but are occasionally transmitted to other species, including humans, where they cause subclinical to fatal disease. To date, the effect of LPAIV-specific immunity on the epidemiology of LPAIV in wild birds is poorly understood. In this study, we investigated the effect of H13 and H16 LPAIV infection in black-headed gulls on susceptibility and virus excretion of

  6. Relationships between polybrominated diphenyl ethers and transcription and activity of type 1 deiodinase in a gull highly exposed to flame retardants.

    PubMed

    François, Anthony; Técher, Romy; Houde, Magali; Spear, Philip; Verreault, Jonathan

    2016-09-01

    Deca-brominated diphenyl ether (deca-BDE), composed mainly of BDE-209, is subject to usage restrictions in North America and Europe, although global action on its continued use has yet to be undertaken. Relatively large concentrations of polybrominated diphenyl ethers (PBDEs), especially BDE-209 and its higher brominated degradation products, have been reported in tissues of ring-billed gulls (Larus delawarensis) breeding near the densely populated city of Montreal (QC, Canada). There is limited knowledge of BDE-209 biotransformation and toxicokinetics in birds. Deiodinases, a class of enzymes catalyzing thyroid hormone conversion, have been suggested to be involved in BDE-209 debromination in birds. The objective of the present study was to investigate the relationships between PBDE concentrations and type 1 deiodinase (D1) transcription and in vitro activity (microsomes) in livers of Montreal-breeding ring-billed gulls. The ring-billed gulls exhibiting the highest D1 activity in liver microsomes accumulated the greatest liver concentrations of hepta-BDEs and octa-BDEs. Activity of D1 was inversely related to concentration ratios of BDE-209 to octa-BDEs and ∑hepta-BDE. An even stronger inverse relation was found between D1 activity and BDE-209 to ∑nona + octa + hepta-BDE concentration ratios. The messenger ribonucleic acid (mRNA) levels of D1 in gull livers were inversely associated with liver concentrations of ∑octa-BDE. The present study's findings suggest that D1 is potentially involved in BDE-209 biotransformation and accumulation of higher brominated PBDEs in livers of ring-billed gulls. Environ Toxicol Chem 2016;35:2215-2222. © 2016 SETAC. PMID:27336952

  7. Streamlined Island

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-514, 15 October 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows a streamlined island in Marte Vallis, a large outflow channel system that crosses the 180oW meridian between the Elysium and Amazonis regions of Mars. The flow patterns on the floor of Marte Vallis might be the remains of lava flows or mud flows. Marte is the Spanish word for Mars. Most of the largest valleys on the red planet are named for 'Mars' in various languages. This island is located near 21.8oN, 175.3oW. The picture covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left.

  8. Classifying Pacific islands

    NASA Astrophysics Data System (ADS)

    Nunn, Patrick D.; Kumar, Lalit; Eliot, Ian; McLean, Roger F.

    2016-12-01

    An earth-science-based classification of islands within the Pacific Basin resulted from the preparation of a database describing the location, area, and type of 1779 islands, where island type is determined as a function of the prevailing lithology and maximum elevation of each island, with an island defined as a discrete landmass composed of a contiguous land area ≥1 ha (0.01 km2) above mean high-water level. Reefs lacking islands and short-lived (<20 years) transient islands are not included. The principal aim of the classification is to assess the spatial diversity of the geologic and geomorphic attributes of Pacific islands. It is intended to be valid at a regional scale and based on two attributes: five types of lithology (volcanic, limestone, composite, continental, surficial) and a distinction between high and low islands. These attributes yielded eight island types: volcanic high and low islands; limestone high and low islands; composite high and low islands; reef (including all unconsolidated) islands; and continental islands. Most common are reef islands (36 %) and volcanic high islands (31 %), whereas the least common are composite low islands (1 %). Continental islands, 18 of the 1779 islands examined, are not included in maps showing the distribution of island attributes and types. Rationale for the spatial distributions of the various island attributes is drawn from the available literature and canvassed in the text. With exception of the few continental islands, the distribution of island types is broadly interpretable from the proximity of island-forming processes. It is anticipated the classification will become the basis for more focused investigation of spatial variability of the climate and ocean setting as well as the biological attributes of Pacific islands. It may also be used in spatial assessments of second-order phenomena associated with the islands, such as their vulnerability to various disasters, coastal erosion, or ocean pollution as

  9. Nematode diversity, abundance and community structure 50 years after the formation of the volcanic island of Surtsey

    NASA Astrophysics Data System (ADS)

    Ilieva-Makulec, K.; Bjarnadottir, B.; Sigurdsson, B. D.

    2014-10-01

    The soil nematode fauna can give important insights into soil development and other habitat changes that occur during primary succession. We investigated the generic composition, density, distribution and community structure of nematodes 50 years after the formation of a pristine volcanic island, Surtsey, Iceland. Part of the island has received additional nutrient inputs from seagulls breeding there since 1985, while the reminder has been much less affected and is at present found at a different successional sere. In total, 25 genera of nematodes were identified, of which 14 were reported on Surtsey for the first time. Nematode communities were more diverse in the more infertile area outside the gull colony, where 24 genera were found, compared to 18 inside. The trophic structure of the nematode communities showed relatively higher abundance of fungal feeders in the infertile areas, but relatively more bacterial- and plant-feeders inside the colony. Nematode abundance in surface soil was, however, significantly higher within the gull colony, with 16.7 ind. cm-2 compared to 3.6 ind. cm-2 outside. A multivariate analysis indicated that the nematode abundance and distribution on Surtsey were most strongly related to the soil C : N ratio, soil acidity, plant cover and biomass, soil temperature and soil depth.

  10. Groundwater flow near the Shoal Site, Sand Springs Range, Nevada: Impact of density-driven flow

    SciTech Connect

    Chapman, J.; Mihevc, T.; McKay, A.

    1994-09-01

    The nature of flow from a highland recharge area in a mountain range in north-central Nevada to discharge areas on either side of the range is evaluated to refine a conceptual model of contaminant transport from an underground nuclear test conducted beneath the range. The test, known as the Shoal event, was conducted in 1963 in granitic rocks of the Sand Springs Range. Sparse hydraulic head measurements from the early 1960s suggest flow from the shot location to the east to Fairview Valley, while hydrochemistry supports flow to salt pans in Fourmile Flat to the west. Chemical and isotopic data collected from water samples and during well-logging arc best explained by a reflux brine system on the west side of the Sand Springs Range, rather than a typical local flow system where all flow occurs from recharge areas in the highlands to a central discharge area in a playa. Instead, dense saline water from the playa is apparently being driven toward the range by density contrasts. The data collected between the range and Fourmile Flat suggest the groundwater is a mixture of younger, fresher recharge water with older brine. Chemical contrasts between groundwater in the east and west valleys reflect the absence of re-flux water in Fairview Valley because the regional discharge area is distant and thus there is no accumulation of salts. The refluxing hydraulic system probably developed after the end of the last pluvial period and differences between the location of the groundwater divide based on hydraulic and chemical indicators could reflect movement of the divide as the groundwater system adjusts to the new reflux condition.

  11. Weak response of oceanic dimethylsulfide to upper mixing shoaling induced by global warming.

    PubMed

    Vallina, S M; Simó, R; Manizza, M

    2007-10-01

    The solar radiation dose in the oceanic upper mixed layer (SRD) has recently been identified as the main climatic force driving global dimethylsulfide (DMS) dynamics and seasonality. Because DMS is suggested to exert a cooling effect on the earth radiative budget through its involvement in the formation and optical properties of tropospheric clouds over the ocean, a positive relationship between DMS and the SRD supports the occurrence of a negative feedback between the oceanic biosphere and climate, as postulated 20 years ago. Such a natural feedback might partly counteract anthropogenic global warming through a shoaling of the mixed layer depth (MLD) and a consequent increase of the SRD and DMS concentrations and emission. By applying two globally derived DMS diagnostic models to global fields of MLD and chlorophyll simulated with an Ocean General Circulation Model coupled to a biogeochemistry model for a 50% increase of atmospheric CO(2) and an unperturbed control run, we have estimated the response of the DMS-producing pelagic ocean to global warming. Our results show a net global increase in surface DMS concentrations, especially in summer. This increase, however, is so weak (globally 1.2%) that it can hardly be relevant as compared with the radiative forcing of the increase of greenhouse gases. This contrasts with the seasonal variability of DMS (1000-2000% summer-to-winter ratio). We suggest that the "plankton-DMS-clouds-earth albedo feedback" hypothesis is less strong a long-term thermostatic system than a seasonal mechanism that contributes to regulate the solar radiation doses reaching the earth's biosphere. PMID:17901211

  12. Oxygen limitations on marine animal distributions and the collapse of epibenthic community structure during shoaling hypoxia.

    PubMed

    Chu, Jackson W F; Tunnicliffe, Verena

    2015-08-01

    Deoxygenation in the global ocean is predicted to induce ecosystem-wide changes. Analysis of multidecadal oxygen time-series projects the northeast Pacific to be a current and future hot spot of oxygen loss. However, the response of marine communities to deoxygenation is unresolved due to the lack of applicable data on component species. We repeated the same benthic transect (n = 10, between 45 and 190 m depths) over 8 years in a seasonally hypoxic fjord using remotely operated vehicles equipped with oxygen sensors to establish the lower oxygen levels at which 26 common epibenthic species can occur in the wild. By timing our surveys to shoaling hypoxia events, we show that fish and crustacean populations persist even in severe hypoxia (<0.5 mL L(-1) ) with no mortality effects but that migration of mobile species occurs. Consequently, the immediate response to hypoxia expansion is the collapse of community structure; normally partitioned distributions of resident species coalesced and localized densities increased. After oxygen renewal and formation of steep oxygen gradients, former ranges re-established. High frequency data from the nearby VENUS subsea observatory show the average oxygen level at our site declined by ~0.05 mL L(-1) year(-1) over the period of our study. The increased annual duration of the hypoxic (<1.4 mL L(-1) ) and severely hypoxic periods appears to reflect the oxygen dynamics demonstrated in offshore source waters and the adjacent Strait of Georgia. Should the current trajectory of oxygen loss continue, community homogenization and reduced suitable habitat may become the dominant state of epibenthic systems in the northeast Pacific. In situ oxygen occurrences were not congruent with lethal and sublethal hypoxia thresholds calculated across the literature for major taxonomic groups indicating that research biases toward laboratory studies on Atlantic species are not globally applicable. Region-specific hypoxia thresholds are necessary to

  13. Investigation of suspected gulls in the Jurassic limestone strata of the Cotswold Hills, Gloucestershire, England using electrical resistivity tomography

    NASA Astrophysics Data System (ADS)

    Barron, A. J. M.; Uhlemann, S.; Pook, G. G.; Oxby, L.

    2016-09-01

    An electrical resistivity tomography survey has clearly indicated the presence of substantial vertical zones of contrasting material beneath a set of conspicuous linear surface hollows that cut across a spur forming part of the Cotswold Hills escarpment in Gloucestershire. These zones are compared with nearby quarry exposures and are inferred to be gulls - graben-like structures at least 80 m deep filled with collapsed blocks of bedrock with intervening air-filled spaces, lying within areas of relatively undisrupted gently dipping strata, and which under some circumstances would present a significant geohazard. Our results confirm the great potential of this non-invasive and rapid survey technique for investigating such phenomena, and provide an exemplar for comparison with surveys elsewhere, to assist identification of similar features.

  14. Carolinas Coastal Change Processes Project data report for observations near Diamond Shoals, North Carolina, January-May 2009

    USGS Publications Warehouse

    Armstrong, Brandy N.; Warner, John C.; Voulgaris, George; List, Jeffrey H.; Thieler, E. Robert; Martini, Marinna A.; Montgomery, Ellyn T.

    2011-01-01

    This Open-File Report provides information collected for an oceanographic field study that occurred during January - May 2009 to investigate processes that control the sediment transport dynamics at Diamond Shoals, North Carolina. The objective of this report is to make the data available in digital form and to provide information to facilitate further analysis of the data. The report describes the background, experimental setup, equipment, and locations of the sensor deployments. The edited data are presented in time-series plots for rapid visualization of the data set, and in data files that are in the Network Common Data Format (netcdf). Supporting observational data are also included.

  15. Effectiveness of a refuge for Lake Trout in Western Lake Superior II: Simulation of future performance

    USGS Publications Warehouse

    Akins, Andrea L; Hansen, Michael J.; Seider, Michael J.

    2015-01-01

    Historically, Lake Superior supported one of the largest and most diverse Lake Trout Salvelinus namaycush fisheries in the Laurentian Great Lakes, but Lake Trout stocks collapsed due to excessive fishery exploitation and predation by Sea Lampreys Petromyzon marinus. Lake Trout stocking, Sea Lamprey control, and fishery regulations, including a refuge encompassing Gull Island Shoal (Apostle Islands region), were used to enable recovery of Lake Trout stocks that used this historically important spawning shoal. Our objective was to determine whether future sustainability of Lake Trout stocks will depend on the presence of the Gull Island Shoal Refuge. We constructed a stochastic age-structured simulation model to assess the effect of maintaining the refuge as a harvest management tool versus removing the refuge. In general, median abundances of age-4, age-4 and older (age-4+), and age-8+ fish collapsed at lower instantaneous fishing mortality rates (F) when the refuge was removed than when the refuge was maintained. With the refuge in place, the F that resulted in collapse depended on the rate of movement into and out of the refuge. Too many fish stayed in the refuge when movement was low (0–2%), and too many fish became vulnerable to fishing when movement was high (≥22%); thus, the refuge was more effective at intermediate rates of movement (10–11%). With the refuge in place, extinction did not occur at any simulated level of F, whereas refuge removal led to extinction at all combinations of commercial F and recreational F. Our results indicate that the Lake Trout population would be sustained by the refuge at all simulated F-values, whereas removal of the refuge would risk population collapse at much lower F (0.700–0.744). Therefore, the Gull Island Shoal Refuge is needed to sustain the Lake Trout population in eastern Wisconsin waters of Lake Superior.

  16. Associations between organohalogen concentrations and transcription of thyroid-related genes in a highly contaminated gull population.

    PubMed

    Técher, Romy; Houde, Magali; Verreault, Jonathan

    2016-03-01

    A number of studies have reported altered circulating thyroid hormone levels in birds exposed either in controlled settings or in their natural habitat to ubiquitous organohalogen compounds including organochlorines (OCs) and polybrominated diphenyl ether (PBDE) flame retardants. However, limited attention has been paid to underlying homeostatic mechanisms in wild birds such as changes in the expression of genes in the hypothalamic-pituitary-thyroid (HPT) axis. The objective of the present study was to investigate the relationships between hepatic concentrations of major organohalogens (PBDEs and OCs), and circulating thyroid hormone (free and total thyroxine (T4) and triiodothyronine (T3)) levels and transcription of 14 thyroid-related genes in three tissues (thyroid, brain, and liver) of an urban-adapted bird exposed to high organohalogen concentrations in the Montreal area (QC, Canada), the ring-billed gull (Larus delawarensis). Positive correlations were found between liver concentrations of several polychlorinated biphenyls (PCBs), PBDEs as well as chlordanes and total plasma T4 levels. Hepatic concentrations of several PBDEs were negatively correlated with mRNA levels of deiodinase type 3, thyroid peroxidase, and thyroid hormone receptor β (TRβ) in the thyroid gland. Liver PCB (deca-CB) correlated positively with mRNA levels of sodium-iodide symporter and TRα. In brain, concentrations of most PBDEs were positively correlated with mRNA levels of organic anion transporter protein 1C1 and transthyretin, while PCBs positively correlated with expression of TRα and TRβ as well as deiodinase type 2. These multiple correlative linkages suggest that organohalogens operate through several mechanisms (direct or compensatory) involving gene transcription, thus potentially perturbing the HPT axis of this highly organohalogen-contaminated ring-billed gull population. PMID:26747993

  17. Comparative body compartment composition and in ovo transfer of organophosphate flame retardants in North American Great Lakes herring gulls.

    PubMed

    Greaves, Alana K; Letcher, Robert J

    2014-07-15

    Although recent usage of organophosphate (OP) flame retardants has increased substantially, very few studies have reported on OPs in biota including wildlife, and essentially there is no information on OP body compartment composition and in ovo or in utero transfer for any given wildlife species. Concentrations and patterns of 16 OP triesters were presently screened for and/or determined in six body compartments from female herring gulls (Larus argentatus; n=8) and the separate egg yolk and albumen of their entire clutches of eggs (n=16) (collected in 2010 from a Lake Huron colony site, Laurentian Great Lakes of North America). Fat (32.3±9.8 ng/g wet weight; ww) contained the highest ΣOP concentration, followed by egg yolk (14.8±2.4 ng/g ww)≈egg albumen (14.8±5.9 ng/g ww)>muscle (10.9±5.1 ng/g ww)≫red blood cells (1.00±0.62 ng/g ww), whereas in liver, blood plasma, and brain all OPs were not detectable. Nine OPs accumulated in herring gulls, but the concentrations and proportions of OPs were dependent on the body and egg compartment. For example, tris(2-butoxyethyl) phosphate (TBOEP) accounted for 66% of the ΣOP concentration in albumen, but only for 13% in yolk. Tri-n-butyl phosphate (TNBP) accounted for 25% of the ΣOP concentration in yolk, but was not detected in albumen. Estimates showed that overall OP burdens in the body (3.5 μg) were greater than in the whole egg (1.2 μg), although depuration via in ovo transfer was substantial. PMID:24905208

  18. Solomon Islands.

    PubMed

    1988-06-01

    The Solomon Islands, which form an archipelago in the Southwest Pacific about 1900 km northeast of Australia, are described. Included are brief descriptions about such points as geography, people, history, type of government, political conditions, economy, and foreign relations. In 1987 the population was 301,180 (49% under age 14); the annual growth rate was 3.67%. The infant mortality rate is 46/1000; the life expectancy, 54 years. Health conditions in the Solomons generally are adequate, and the country does not suffer from serious endemic diseases other than malaria, in both the vivax and falsiparum strains. Hospitals and pharmacies are limited to population centers and missions. PMID:12177986

  19. Lesser black-backed gulls (Larus fuscus) consuming swimming crabs: An important link in the food web of the southern North Sea

    NASA Astrophysics Data System (ADS)

    Schwemmer, Henriette; Schwemmer, Philipp; Ehrich, Siegfried; Garthe, Stefan

    2013-03-01

    Swimming crabs (Liocarcinus spp.) are one of the most common brachyuran species in the North Sea, and their abundance has substantially increased over the last century. Seabirds such as lesser black-backed gulls (LBBG) commonly feed mainly on higher-trophic-level organisms such as fish. However, intensive use of swimming crabs by LBBGs in the eastern North Sea has been noted over several years. Our investigation of this aspect of the food web by examining food remains from breeding LBBGs showed that swimming crabs accounted for more than half of the nutrition of LBBGs. Gulls selected larger individuals than expected, based on sizes of free-living swimming crabs. A long-term data set (2002-2006) shows that gulls took swimming crabs mainly in the early morning and late evening, suggesting that they might migrate vertically in the water column. Moreover, it shows that although swimming crabs occurred at considerable distances from the shore, LBBGs took this prey item exclusively from near the shore where it was most abundant. This suggests the existence of a possible energy threshold above which gulls experience a net energy loss, if they have to travel too far from their colony, where the abundance of swimming crabs is lower and the energy intake might thus not compensate for the long-distance flights. Swimming-crab abundance did not appear to be the primary factor influencing overall gull distribution. A simple bioenergetic model showed that the 22,000 individual LBBGs in the most important breeding colony in the south-eastern North Sea consumed approximately 35 million swimming crabs annually (i.e. 1590 swimming crabs per individual gull) during the breeding period. However, considering the high numbers of swimming crabs in the south-eastern North Sea (demonstrated by bottom-trawl surveys in 2005 and 2007) LBBGs are unlikely to exert top-down control on this prey. Conversely, a bottom-up effect is more likely, potentially enabling further increases in LBBG

  20. Coastal bathymetry data collected in June 2014 from Fire Island, New York—The wilderness breach and shoreface

    USGS Publications Warehouse

    Nelson, Timothy R.; Miselis, Jennifer L.; Hapke, Cheryl J.; Wilson, Kathleen E.; Henderson, Rachel E.; Brenner, Owen T.; Reynolds, Billy J.; Hansen, Mark E.

    2016-01-01

    Scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida, collected bathymetric data along the upper shoreface and within the wilderness breach at Fire Island, New York, in June 2014. The U.S. Geological Survey is involved in a post-Hurricane Sandy effort to map and monitor the morphologic evolution of the shoreface along Fire Island and model the evolution of the wilderness breach as a part of the Hurricane Sandy Supplemental Project GS2-2B. During this study, bathymetry was collected with single-beam echo sounders and global positioning systems, mounted to personal watercraft, along the Fire Island shoreface and within the wilderness breach. Additional bathymetry was collected using backpack global positioning systems along the flood shoals and shallow channels within the wilderness breach.

  1. 2012 Groundwater Monitoring Report Project Shoal Area Subsurface Corrective Action Unit 447

    SciTech Connect

    2013-03-01

    The Project Shoal Area (PSA) in Nevada was the site of a 12-kiloton underground nuclear test in 1963. Although the surface of the site has been remediated, investigation of groundwater contamination resulting from the test is still in the corrective action process. Annual sampling and hydraulic head monitoring are conducted at the site as part of the subsurface corrective action strategy. Analytical results from the 2012 monitoring are consistent with those of the previous years, with tritium detected only in well HC-4. The tritium concentration in groundwater from well HC-4 remains far below the U.S. Environmental Protection Agency-established maximum contaminant level of 20,000 picocuries per liter. Concentrations of total uranium and gross alpha were also detected during this monitoring period, with uranium accounting for nearly all the gross alpha activity. The total uranium concentrations obtained from this monitoring period were consistent with previous results and reflect a slightly elevated natural uranium concentration, consistent with the mineralized geologic terrain. Isotopic ratios of uranium also indicate a natural source of uranium in groundwater, as opposed to a nuclear-test-related source. Water level trends obtained from the 2012 water level data were consistent with those of previous years. The corrective action strategy for the PSA is currently focused on revising the site conceptual model (SCM) and evaluating the adequacy of the current monitoring well network. Some aspects of the SCM are known; however, two major concerns are the uncertainty in the groundwater flow direction and the cause of rising water levels in site wells west of the shear zone. Water levels have been rising in the site wells west of the shear zone since the first hydrologic characterization wells were installed in 1996. While water levels in wells west of the shear zone continue to rise, the rate of increase is less than in previous years. The SCM will be revised, and an

  2. Island Formation: Constructing a Coral Island

    ERIC Educational Resources Information Center

    Austin, Heather; Edd, Amelia

    2009-01-01

    The process of coral island formation is often difficult for middle school students to comprehend. Coral island formation is a dynamic process, and students should have the opportunity to experience this process in a synergistic context. The authors provide instructional guidelines for constructing a coral island. Students play an interactive role…

  3. Adapting to a Changing World: Unraveling the Role of Man-Made Habitats as Alternative Feeding Areas for Slender-Billed Gull (Chroicocephalus genei)

    PubMed Central

    Ramírez, Francisco; Navarro, Joan; Afán, Isabel; Hobson, Keith A.; Delgado, Antonio; Forero, Manuela G.

    2012-01-01

    Current rates of wildlife habitat loss have placed increasing demands on managers to develop, validate and implement tools aimed at improving our ability to evaluate such impacts on wildlife. Here, we present a case study conducted at the Natural Area of Doñana (SW Spain) where remote sensing and stable isotope (δ13C, δ15N) analyses of individuals were combined to unravel (1) the effect of variations in availability of natural food resources (i.e. from natural marshes) on reproductive performance of a Slender-billed Gull (Chroicocephalus genei) population, and (2) the role of two adjacent, artificial systems (a fish farm and saltmines) as alternate anthropogenic feeding areas. Based on long-term (1983–2004) remote-sensing, we inferred the average extent of flooded area at the marshland (a proxy to natural resource availability) annually. Estimated flooded areas (ranging from extreme drought [ca. 151 ha, 1995] to high moisture [15,049 ha, 2004]) were positively related to reproductive success of gulls (estimated for the 1993–2004 period, and ranging from ca. 0 to 1.7 fledglings per breeding pairs), suggesting that habitat availability played a role in determining their reproductive performance. Based on blood δ13C and δ15N values of fledglings, 2001–2004, and a Bayesian isotopic mixing model, we conclude that saltmines acted as the main alternative foraging habitat for gulls, with relative contributions increasing as the extent of marshland decreased. Although adjacent, anthropogenic systems have been established as the preferred breeding sites for this gull population, dietary switches towards exploitation of alternative (anthropogenic) food resources negatively affected the reproductive output of this species, thus challenging the perception that these man-made systems are necessarily a reliable buffer against loss of natural feeding habitats. The methodology and results derived from this study could be extended to a large suite of threatened natural

  4. Impact of changes in analytical techniques for the measurement of polychlorinated biphenyls and organochlorine pesticides on temporal trends in herring gull eggs.

    PubMed

    de Solla, Shane R; Weseloh, D V Chip; Hebert, Craig E; Pekarik, Cynthia

    2010-07-01

    Changes in analytical approaches during the tenure of monitoring programs for organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs) may affect estimates of temporal trends. We used an in-house reference material to create multiplication factors to adjust the estimates of OC pesticides and PCBs (Aroclor equivalents) in Great Lake herring gull eggs analyzed using electron capture detection (1987-1997) to be more equivalent to estimates using mass spectrometric detection (1998-2005) as well as accompanying differences in analytical procedures. We examined temporal trends in contaminant concentrations in herring gull eggs using change point regressions, to determine whether significant changes in long-term trends were associated with analytical methodology. The highest frequency of change point occurrences shifted from 1997 (when analytical methodology was altered) to 2003 after data adjustment. The explanatory power (r2) of the regressions was lower after adjustment, although only marginally so (mean r2 difference=0.04). The initial rates of decline before change points in contaminant concentrations were generally slower after the data adjustment, but after any change points the declines were not significantly different. The regression models did not change for 83.3% of the cases. The effects on the interpretation of long-term temporal trends in herring gull eggs, although not negligible, were minor relative to the magnitude of the temporal changes. PMID:20821596

  5. Developmental toxicity of PFOS and PFOA in great cormorant (Phalacrocorax carbo sinensis), herring gull (Larus argentatus) and chicken (Gallus gallus domesticus).

    PubMed

    Nordén, Marcus; Berger, Urs; Engwall, Magnus

    2016-06-01

    Perfluoroalkyl acids (PFAAs) are found globally in environmental samples and have been studied in various species. In this study, we compare the sensitivity of three avian species to the toxic effects of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA). Eggs of great cormorant (Phalacrocorax carbo sinensis), herring gull (Larus argentatus) and the domestic White Leghorn chicken (Gallus gallus domesticus) were exposed in ovo by injection into the air sac. Effects on embryo survival were observed following exposure to PFOS and PFOA in chicken and herring gull. Chicken was found to be the most sensitive species with 50 % reduced embryo survival at 8.5 μg/g egg for PFOS and 2.5 μg/g egg for PFOA. Cormorant was shown to be the least sensitive species. The difference in sensitivity between chicken and herring gull was a factor of 2.7 for PFOS and 3.5 for PFOA. Between chicken and great cormorant, the sensitivity difference was 2.6 for PFOS and 8.2 for PFOA. Effects on embryo survival were seen at egg injection doses of PFOS close to levels found in environmental samples from wild birds, indicating that PFOS could be having effects in highly exposed populations of birds. This study also shows that there are differences in species sensitivity to PFOS and PFOA that should be taken into consideration in avian wildlife risk assessment. PMID:26895726

  6. 46 CFR 401.407 - Basic rates and charges on Lake Erie and the navigable waters from Southeast Shoal to Port Huron...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Basic rates and charges on Lake Erie and the navigable waters from Southeast Shoal to Port Huron, MI. 401.407 Section 401.407 Shipping COAST GUARD (GREAT LAKES PILOTAGE), DEPARTMENT OF HOMELAND SECURITY GREAT LAKES PILOTAGE REGULATIONS Rates, Charges, and Conditions for Pilotage Services § 401.407...

  7. Low-frequency target strength and abundance of shoaling Atlantic herring (Clupea harengus) in the Gulf of Maine during the Ocean Acoustic Waveguide Remote Sensing 2006 Experiment.

    PubMed

    Gong, Zheng; Andrews, Mark; Jagannathan, Srinivasan; Patel, Ruben; Jech, J Michael; Makris, Nicholas C; Ratilal, Purnima

    2010-01-01

    The low-frequency target strength of shoaling Atlantic herring (Clupea harengus) in the Gulf of Maine during Autumn 2006 spawning season is estimated from experimental data acquired simultaneously at multiple frequencies in the 300-1200 Hz range using (1) a low-frequency ocean acoustic waveguide remote sensing (OAWRS) system, (2) areal population density calibration with several conventional fish finding sonar (CFFS) systems, and (3) low-frequency transmission loss measurements. The OAWRS system's instantaneous imaging diameter of 100 km and regular updating enabled unaliased monitoring of fish populations over ecosystem scales including shoals of Atlantic herring containing hundreds of millions of individuals, as confirmed by concurrent trawl and CFFS sampling. High spatial-temporal coregistration was found between herring shoals imaged by OAWRS and concurrent CFFS line-transects, which also provided fish depth distributions. The mean scattering cross-section of an individual shoaling herring is found to consistently exhibit a strong, roughly 20 dB/octave roll-off with decreasing frequency in the range of the OAWRS survey over all days of the roughly 2-week experiment, consistent with the steep roll-offs expected for sub-resonance scattering from fish with air-filled swimbladders. PMID:20058955

  8. 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.

  9. Field Metabolic Rate Is Dependent on Time-Activity Budget in Ring-Billed Gulls (Larus delawarensis) Breeding in an Anthropogenic Environment.

    PubMed

    Marteinson, Sarah C; Giroux, Jean-François; Hélie, Jean-François; Gentes, Marie-Line; Verreault, Jonathan

    2015-01-01

    Environmental and behavioral factors have long been assumed to affect variation in avian field metabolic rate (FMR). However, due to the difficulties in measuring continuous behavior of birds over prolonged periods of time, complete time-activity budgets have rarely been examined in relation to FMR. Our objective was to determine the effect of activity (measured by detailed time-activity budgets) and a series of extrinsic and intrinsic factors on FMR of the omnivorous ring-billed gull (Larus delawarensis). The experiment was conducted during the incubation period when both members of the pair alternate between attending the nest-site and leaving the colony to forage in aquatic and anthropogenic environments (city, agricultural). FMR was determined using the doubly labeled water method. Time-activity budgets were extrapolated from spatio-temporal data (2-5 days) obtained from bird-borne GPS data loggers. Gulls had low FMRs compared to those predicted by allometric equations based on recorded FMRs from several seabird species. Gulls proportioned their time mainly to nest-site attendance (71% of total tracking time), which reduced FMR/g body mass, and was the best variable explaining energy expenditure. The next best variable was the duration of foraging trips, which increased FMR/g; FMR/g was also elevated by the proportion of time spent foraging or flying (17% and 8% of tracking time respectively). Most environmental variables measured did not impact FMR/g, however, the percent of time birds were subjected to temperatures below their lower critical temperature increased FMR. Time-activity budgets varied between the sexes, and with temperature and capture date suggesting that these variables indirectly affected FMR/g. The gulls foraged preferentially in anthropogenic-related habitats, which may have contributed to their low FMR/g due to the high availability of protein- and lipid-rich foods. This study demonstrates that activities were the best predictors of FMR/g in

  10. Field Metabolic Rate Is Dependent on Time-Activity Budget in Ring-Billed Gulls (Larus delawarensis) Breeding in an Anthropogenic Environment

    PubMed Central

    Marteinson, Sarah C.; Giroux, Jean-François; Hélie, Jean-François; Gentes, Marie-Line; Verreault, Jonathan

    2015-01-01

    Environmental and behavioral factors have long been assumed to affect variation in avian field metabolic rate (FMR). However, due to the difficulties in measuring continuous behavior of birds over prolonged periods of time, complete time-activity budgets have rarely been examined in relation to FMR. Our objective was to determine the effect of activity (measured by detailed time-activity budgets) and a series of extrinsic and intrinsic factors on FMR of the omnivorous ring-billed gull (Larus delawarensis). The experiment was conducted during the incubation period when both members of the pair alternate between attending the nest-site and leaving the colony to forage in aquatic and anthropogenic environments (city, agricultural). FMR was determined using the doubly labeled water method. Time-activity budgets were extrapolated from spatio-temporal data (2-5 days) obtained from bird-borne GPS data loggers. Gulls had low FMRs compared to those predicted by allometric equations based on recorded FMRs from several seabird species. Gulls proportioned their time mainly to nest-site attendance (71% of total tracking time), which reduced FMR/g body mass, and was the best variable explaining energy expenditure. The next best variable was the duration of foraging trips, which increased FMR/g; FMR/g was also elevated by the proportion of time spent foraging or flying (17% and 8% of tracking time respectively). Most environmental variables measured did not impact FMR/g, however, the percent of time birds were subjected to temperatures below their lower critical temperature increased FMR. Time-activity budgets varied between the sexes, and with temperature and capture date suggesting that these variables indirectly affected FMR/g. The gulls foraged preferentially in anthropogenic-related habitats, which may have contributed to their low FMR/g due to the high availability of protein- and lipid-rich foods. This study demonstrates that activities were the best predictors of FMR/g in

  11. Tracking the History and Ecological Changes of Rising Double-Crested Cormorant Populations Using Pond Sediments from Islands in Eastern Lake Ontario

    PubMed Central

    Stewart, Emily M.; Michelutti, Neal; Shenstone-Harris, Sarah; Grooms, Christopher; Weseloh, Chip; Kimpe, Linda E.; Blais, Jules M.; Smol, John P.

    2015-01-01

    In the Laurentian Great Lakes region, the double-crested cormorant (Phalacrocorax auritus) has seen a thousand-fold population increase in recent decades. These large colonies of birds now often conflict with socioeconomic interests, particularly due to perceived competition with fisheries and the destruction of terrestrial vegetation in nesting habitats. Here we use dated sediment cores from ponds on islands in eastern Lake Ontario that receive waste inputs from dense colonies of cormorants and ring-billed gulls (Larus delawarensis) to chronicle the population rise of these species and assess their long-term ecological impacts. Modern water chemistry sampling from these sites reveals drastically elevated nutrient and major ion concentrations compared to reference ponds not influenced by waterbirds. Geochemical tracers in dated sediment cores, particularly δ15N and chlorophyll-a concentrations, track waterbird influences over time. Fossil diatom assemblages were dominated by species tolerant of hyper-eutrophic and polluted systems, which is in marked contrast to assemblages in reference sites. In addition to establishing long-term ecological impacts, this multi-proxy paleoecological approach can be used to determine whether islands of concern have been long-term nesting sites or were only recently colonized by cormorant or ring-billed gull populations across the Great Lakes, facilitating informed management decisions about controversial culling programs. PMID:26214177

  12. Well Completion Report for Corrective Action Unit 447, Project Shoal Area, Churchill County, Nevada, Rev. No.: 0

    SciTech Connect

    Rick Findlay

    2006-09-01

    This Well Completion Report is being provided as part of the implementation of the Corrective Action Decision Document (CADD)/Corrective Action Plan (CAP) for Corrective Action Unit (CAU) 447 (NNSA/NSO, 2006a). The CADD/CAP is part of an ongoing U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) funded project for the investigation of CAU 447 at the Project Shoal Area (PSA). All work performed on this project was conducted in accordance with the ''Federal Facility Agreement and Consent Order'' (FFACO) (1996), and all applicable Nevada Division of Environmental Protection (NDEP) policies and regulations. Investigation activities included the drilling, construction, and development of three monitoring/validation (MV) wells at the PSA. This report summarizes the field activities and data collected during the investigation.

  13. Rapid vertical accretion on a `young' shore-detached turbid zone reef: Offshore Paluma Shoals, central Great Barrier Reef, Australia

    NASA Astrophysics Data System (ADS)

    Perry, C. T.; Smithers, S. G.; Gulliver, P.

    2013-12-01

    We report on the age structure and net accretion rates determined for an open water turbid zone reef, known as Offshore Paluma Shoals, located on the inner central Great Barrier Reef. Twenty-eight radiocarbon dates from 5 cores through the reef structure indicate that this reef began growing ~1,700 years ago and that net vertical accretion through the main phase of reef development was rapid (averaging 7.8 mm yr-1), this despite the reef growing in highly turbid waters. The most rapid growth phases coincided with the accumulation of mud-rich terrigenoclastic sediments within the reef fabric. The study emphasises the capacity of turbid zone reefs to vertically accrete at rates matching or exceeding many clear water reefs despite seemingly detrimental water quality conditions.

  14. Seasonal variations in aldrin epoxidase (MFO) activity of yellow-legged herring gulls: the relationship to breeding and PCB residues

    SciTech Connect

    Fossi, C.; Leonzio, C.; Focardi, S.; Renzoni, A.

    1988-09-01

    The hepatic mixed function oxidases (MFO) constitute a defense mechanism which enables the organism to make xenobiotics more polar and thus render them more readily excretable. The degree of induction of this system is an expression of its exposure to xenobiotics, but it is also a function of endogenous physiological mechanisms. These two forms of induction may lead to mutual interference: foreign compounds may stimulate hepatic hydroxylation and affect the metabolism of steroid hormones; the later may in turn stimulate the activity of the MFO system favoring the degradation of the xenobiotics. Induction and detoxication processes of endogenous and exogenous compounds have been observed in mammals in laboratory experiments. Relationships between MRO activity, the reproductive cycle and variations in tissue levels of liposoluble xenobiotics, have been reported for marine organisms. In birds, seasonal variations of MFO levels have been observed, but the relationship between these enzyme variations and the levels of contaminants in the animal tissues has never been made clear. The authors aim to clarify this relationship by determining the levels of PCBs residues and aldrin epoxidase activities in Yellow-legged Herring gull (Larus cachinnans) specimens from different areas of Italy collected during two phases of the annual cycle, namely those of reproduction (spring) and of sexual inactivity (autumn). This species was chosen because of its wide distribution, its opportunistic feeding habits and its adaptive capacity in polluted environments.

  15. Individual and population-level sex-dependent lateralization in yellow-legged gull (Larus michahellis) chicks.

    PubMed

    Romano, Maria; Parolini, Marco; Caprioli, Manuela; Spiezio, Caterina; Rubolini, Diego; Saino, Nicola

    2015-06-01

    Behavioral lateralization at the population level is widespread across vertebrates, with considerable variation among species. However, evidence for individual-level and sex-dependent lateralization is sparse and inconsistent in fish, reptiles and birds. In addition, covariation of lateralization with position in the laying sequence, which is expected because the concentration of maternal egg hormones varies with laying order, has never been investigated. We analyzed lateralization of yellow-legged gull (Larus michahellis) chicks in reverting from supine to prone posture ('RTP' response) and in pecking at a dummy parental bill to solicit food provisioning ('begging' response). Chicks were lateralized both at the population and at the individual level in the RTP response and at the individual level in begging. Lateralization in the RTP was sex-dependent, as females showed a leftward preference. Lateralization in either motor task was not correlated within individuals. Lateralization did not differ among families, suggesting little additive genetic variation. Lateral preference in begging response varied according to laying order and matched variation in egg androgens concentration. Our study confirms previous findings on population-level lateralization and adds to the scant information on individual-level and heritable variation in lateralization in birds. Moreover, it hints at epigenetic components in lateralization depending on maternal effects. PMID:25818662

  16. Bathymetry of the waters surrounding the Elizabeth Islands, Massachusetts

    USGS Publications Warehouse

    Pendleton, Elizabeth A.; Andrews, Brian D.; Ackerman, Seth D.; Twichell, Dave

    2014-01-01

    The Elizabeth Islands in Massachusetts that separate Vineyard Sound from Buzzards Bay are the remnants of a moraine (unconsolidated glacial sediment deposited at an ice sheet margin; Oldale and O’Hara, 1984). The most recent glacial ice retreat in this region occurred between 25,000 and 20,000 years ago, and the subsequent rise in sea level that followed deglaciation caused differences in the seafloor character between Buzzards Bay and Vineyard Sound. The relatively rough seafloor of Vineyard Sound reflects widespread exposure of glacial material. Shoals mark the location of recessional ice contact material, and deep channels illustrate where meltwater drainage incised glacial deposits. Following ice retreat from the Elizabeth Islands, a glacial lake formed across the mouth of Buzzards Bay, when the lake drained, it scoured two deep channels at the southern end of the bay. Sea level rise began to inundate Vineyard Sound and Buzzards Bay about 8,000 years ago and continues to modify the modern seafloor (Robb and Oldale, 1977). Fine-grained marine and estuarine sediments were deposited in the partially protected setting of Buzzards Bay. These deposits, up to 10 meters in thickness, buried the high-relief glacial landscape and created the generally smooth modern seafloor. In contrast, the Vineyard Sound of today experiences strong tidal currents, which largely prevent the deposition of fine-grained material and constantly rework the glacial sand and gravel within shoals. The seafloor of the sound largely reflects the contours of the ancient glaciated landscape that existed before sea level began to rise. The bathymetric data used to create the hillshaded relief image of the seafloor were collected by the U.S. Geological Survey (USGS) in cooperation with the Massachusetts Office of Coastal Zone Management and supplemented with National Oceanic and Atmospheric Administration hydrographic survey data. The map shows the detailed bathymetry of Buzzards Bay and Vineyard

  17. Recent morphodynamic evolution of the largest uninhibited island in the Yangtze (Changjiang) estuary during 1998-2014: Influence of the anthropogenic interference

    NASA Astrophysics Data System (ADS)

    Wei, Wen; Mei, Xuefei; Dai, Zhijun; Tang, Zhenghong

    2016-08-01

    Estuarine geomorphology worldwide has greatly changed in the Anthropocene due to intensive human inferences in river basin and within estuary, which has received increasing global concerns. Here, recent morphodynamic evolution of Jiuduan Shoal (JDS), the largest uninhabited island in the Yangtze (Changjiang) Estuary, and associated controlling factors were analyzed based on unique high-resolution seasonal-surveyed bathymetric data during 1998-2014. It can be indicated that JDS presents novel 12 and 48 months fluctuations though significant accretion was detected on high flats above -2 m. Meanwhile, morphodynamic evolution of JDS during 1998-2014 was divided into three stages: significant siltation on landward half of north JDS and expanding of Jiangya Shoal (JYS, part of JDS) tail, but less accretion at high flats from 1998 to 2002; continuous variations of JYS and reshape of seaward JDS with erosion band and heave appearance from 2002 to 2006; retentive alteration of JYS but recovery of erosion band and heave, together with redistribution of sand between high and low flats on seaward JDS after 2007. Moreover, river discharge could be likely the key factor controlling periodic characteristics of recent JDS evolution. Deep waterway project (DWP) dominates area increase of JDS by inducing accretion in north edge and south edge of Lower Shoal between 1998 and 2014.

  18. UAS-based automatic bird count of a common gull colony

    NASA Astrophysics Data System (ADS)

    Grenzdörffer, G. J.

    2013-08-01

    The standard procedure to count birds is a manual one. However a manual bird count is a time consuming and cumbersome process, requiring several people going from nest to nest counting the birds and the clutches. High resolution imagery, generated with a UAS (Unmanned Aircraft System) offer an interesting alternative. Experiences and results of UAS surveys for automatic bird count of the last two years are presented for the bird reserve island Langenwerder. For 2011 1568 birds (± 5%) were detected on the image mosaic, based on multispectral image classification and GIS-based post processing. Based on the experiences of 2011 the results and the accuracy of the automatic bird count 2012 became more efficient. For 2012 1938 birds with an accuracy of approx. ± 3% were counted. Additionally a separation of breeding and non-breeding birds was performed with the assumption, that standing birds cause a visible shade. The final section of the paper is devoted to the analysis of the 3D-point cloud. Thereby the point cloud was used to determine the height of the vegetation and the extend and depth of closed sinks, which are unsuitable for breeding birds.

  19. Mesoscale geomorphic change on low energy barrier islands in Chesapeake Bay, U.S.A.

    NASA Astrophysics Data System (ADS)

    Cooper, J. Andrew G.

    2013-10-01

    energy barrier islands closely resemble open ocean barrier islands. Continued reworking leads to widening of the inlets with consequent loss of constriction of tidal flow. The tidal deltas are, thus, no longer maintained and ultimately the island system disintegrates through inlet widening and is transformed to subtidal shoals. Barrier islands at various stages in this evolutionary cycle can be observed around the bay. Mid-bay barrier islands are affected by wave processes from both sides. This helps maintain the barrier island form and enables barrier islands to persist as sediment is exchanged between both sides of the island. Rates of barrier island translation are extremely high (up to 30 m/year over a 12 year period). This is attributed to the low volume of sand, which facilitates complete rollover in short periods. Accelerated sea level rise is likely to hasten the translation rates of marsh fringe barrier islands. The rapid disintegration of most spits compared to the persistence of marsh fringe barrier islands points to a reliance on the marsh as a stabilising point. If the marshes are overstepped by rising sea level as appears to be happening, the complete disintegration of the barrier islands is highly likely.

  20. Ground-nesting waterbirds and mammalian carnivores in the Virginia barrier island region: Running out of options

    USGS Publications Warehouse

    Erwin, R.M.; Truitt, B.R.; Jimenez, J.E.

    2001-01-01

    We examined changing patterns of distribution of two large mammalian predators, the raccoon (Procyon lotor) and red fox (Vulpes vulpes), and beach-nesting terns and Black Skimmers (Rynchops niger) along ca. 80 km of the Virginia barrier island landscape between the periods 1975-1977 and 1998. Based on evidence from trapping, scent stations, den observations and sightings of the two predators, there has been a marked increase in their island ranges. In 1975-77, only 6 of the 11 surveyed barrier islands definitely harbored at least one of the two mammals, but by 1998, 11 of 14 islands showed evidence of one or both during the spring and summer. Concurrently, annual beach-nesting bird surveys have been conducted since the mid 1970s during June. From 1977 to 1998, the number of colonies of terns [Common (Sterna hirundo), Gull-billed (S. nilotica), Least (S. antillarum), Royal (S. maxima), and Sandwich (S. sandvicensis)] and Black Skimmers declined from 23 colonies on 11 barrier islands to 13 colonies on 10 islands. In addition, the populations decreased dramatically for all species except the marginal Sandwich Tern and Least Tern. This pattern suggests that mammalian predation may be a major factor in colony site selection or success, although we have no data on success at most locations. The only consistently large colony over the years has been the Royal Tern colony on Fisherman Island, one of the few with no resident large mammals. Because these declining waterbirds appear to be running out of options for safe colony sites in coastal Virginia, we discuss the prospects of conducting limited predator removals on certain islands. In addition, considerations of strict management and enforcement of protection at critical manmade colony sites that now attract large numbers of certain species, are timely. Lastly, where dredged material disposal projects are planned, providing nesting sites for these colonial species and roosting sites for migrant birds may be appropriate.

  1. Barrier Island Hazard Mapping.

    ERIC Educational Resources Information Center

    Pilkey, Orrin H.; Neal, William J.

    1980-01-01

    Describes efforts to evaluate and map the susceptibility of barrier islands to damage from storms, erosion, rising sea levels and other natural phenomena. Presented are criteria for assessing the safety and hazard potential of island developments. (WB)

  2. The shallow stratigraphy and sand resources offshore of the Mississippi Barrier Islands

    USGS Publications Warehouse

    Twichell, David; Pendleton, Elizabeth A.; Baldwin, Wayne; Foster, David; Flocks, James; Kelso, Kyle; DeWitt, Nancy; Pfeiffer, William; Forde, Arnell; Krick, Jason; Baehr, John

    2011-01-01

    Coastal Mississippi is protected by a series of barrier islands ranging in length from 10-25 kilometers that are less than 2 kilometers wide. The majority of these islands comprise the Gulf Islands National Seashore (GUIS), an ecologically diverse shoreline that provides habitat for wildlife including migratory birds and endangered animals. The majority of GUIS is submerged, and aquatic environments include dynamic tidal inlets, ebb-tide deltas, and seagrass beds. The islands are in a state of decline, with land areas severely reduced during the past century by storms, sea-level rise, and human alteration. Morton (2008) estimates that since the mid-1800s up to 64 percent of island surface area has been lost. Heavy damage was inflicted in 2005 by Hurricane Katrina, which passed by as a Category 3 storm and battered the islands with winds of more than 160 kilometers per hour and a storm surge up to 9 meters. Since 2007, the U.S. Geological Survey (USGS), in collaboration with the National Park Service, has been mapping the seafloor and substrate around the islands as part of the USGS Northern Gulf of Mexico Ecosystem Change and Hazard Susceptibility project. The purpose of these investigations is to characterize the near-surface stratigraphy and identify the influence it may have on island evolution and fate. In 2009, this effort provided the basis for a collaborative effort with the U.S. Army Corps of Engineers (USACE) to expand the investigation outside of GUIS boundaries as part of the Mississippi Coastal Improvement Project (MsCIP). The MsCIP program consists of structural, nonstructural, and environmental project elements to restore portions of coastal Mississippi and GUIS affected by storm impact. The project includes the placement of sand along the islands, both on the present beaches and within the littoral zone, to mitigate shoreline erosion and breaching. This action requires the location and assessment of offshore sand or sediment deposits that can provide

  3. Falkland Islands, UK

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This view of the Falkland Islands (52.0S, 58.5W) was taken with a dual camera mount. Compare this scene with STS048-109-043 to analyze the unique properties of each film type. Seldom seen cloud free, the Falkland Islands lie off the southern coast of Argentina. The cold Falklands Ocean Current keeps the islands chilly, ideal for sheep herding and fishing, the two main industries. Colonies of seals and penguins also thrive on the islands.

  4. Arctic ice islands

    SciTech Connect

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.C.

    1988-01-01

    The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.

  5. Changing gull diet in a changing world: a 150-year stable isotope (δ13C, δ15N) record from feathers collected in the Pacific Northwest of North America.

    PubMed

    Blight, Louise K; Hobson, Keith A; Kyser, T Kurt; Arcese, Peter

    2015-04-01

    The world's oceans have undergone significant ecological changes following European colonial expansion and associated industrialization. Seabirds are useful indicators of marine food web structure and can be used to track multidecadal environmental change, potentially reflecting long-term human impacts. We used stable isotope (δ(13)C, δ(15)N) analysis of feathers from glaucous-winged gulls (Larus glaucescens) in a heavily disturbed region of the northeast Pacific to ask whether diets of this generalist forager changed in response to shifts in food availability over 150 years, and whether any detected change might explain long-term trends in gull abundance. Sampled feathers came from birds collected between 1860 and 2009 at nesting colonies in the Salish Sea, a transboundary marine system adjacent to Washington, USA and British Columbia, Canada. To determine whether temporal trends in stable isotope ratios might simply reflect changes to baseline environmental values, we also analysed muscle tissue from forage fishes collected in the same region over a multidecadal timeframe. Values of δ(13)C and δ(15)N declined since 1860 in both subadult and adult gulls (δ(13)C, ~ 2-6‰; δ(15)N, ~4-5‰), indicating that their diet has become less marine over time, and that birds now feed at a lower trophic level than previously. Conversely, forage fish δ(13)C and δ(15)N values showed no trends, supporting our conclusion that gull feather values were indicative of declines in marine food availability rather than of baseline environmental change. Gradual declines in feather isotope values are consistent with trends predicted had gulls consumed less fish over time, but were equivocal with respect to whether gulls had switched to a more garbage-based diet, or one comprising marine invertebrates. Nevertheless, our results suggest a long-term decrease in diet quality linked to declining fish abundance or other anthropogenic influences, and may help to explain regional

  6. Diomede Islands, Bering Straight

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Diomede Islands consisting of the western island Big Diomede (also known as Imaqliq, Nunarbuk or Ratmanov Island), and the eastern island Little Diomede (also known as Krusenstern Island or Inaliq), are two rocky islands located in the middle of the Bering Strait between Russia and Alaska. The islands are separated by an international border and the International Date Line which is approximately 1.5 km from each island; you can look from Alaska into tomorrow in Russia. At the closest land approach between the United States, which controls Little Diomede, and Russia, which controls Big Diomede, they are 3 km apart. Little Diomede Island constitutes the Alaskan City of Diomede, while Big Diomede Island is Russia's easternmost point. The first European to reach the islands was the Russian explorer Semyon Dezhnev in 1648. The text of the 1867 treaty finalizing the sale of Alaska uses the islands to designate the border between the two nations.

    The image was acquired July 8, 2000, covers an area of 13.5 x 10.8 km, and is located at 65.8 degrees north latitude, 169 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  7. Perfluorinated sulfonate and carboxylate compounds and precursors in herring gull eggs from across the Laurentian Great Lakes of North America: Temporal and recent spatial comparisons and exposure implications.

    PubMed

    Letcher, Robert J; Su, Guanyong; Moore, Jeremy N; Williams, Lisa L; Martin, Pamela A; de Solla, Shane R; Bowerman, William W

    2015-12-15

    Chemicals of emerging concern (CECs) in the basin of the Laurentian Great Lakes of North America include per- and poly-fluoroalkyl substances (PFASs) classified as perfluoroalkyl acids. We investigated several PFASs, and specifically 13 C4-C16 perfluorinated carboxylic acids (PFCAs), 4 (C4, C6, C8 and C10) perfluorinated sulfonates (PFSAs), perfluoro-4-ethylcyclohexane sulfonate (PFEtCHxS) and selected precursors (e.g. perfluorobutane sulfonamide and perfluorooctane sulfonamide) in herring gull (Larus argentatus) eggs collected in 2012-2013 from 19 Canadian and U.S. colony sites across the Great Lakes. C6, C8 and C10 PFSAs, PFEtCHxS, and C7-14 and C16 PFCAs were quantifiable at >97% of the 114 egg samples. PFEtCHxS concentrations ranged from n.d. to 3.1ng/g ww (highest in Lake Michigan eggs). Mean Σ4PFSA (92 to 97% perfluorooctane sulfonate (PFOS)) and Σ9PFCA concentration ranges were 44 to 740 and 4.8 to 118ng/g ww, respectively. Σ4PFSA showed a clear increasing concentration trend from the northwest to the southeast colonies. Also, Σ4PFCA to Σ9PFSA concentration ratios in gull eggs were greater in eggs from Lake Superior relative to colonies in the other lakes. PFOS concentrations in some egg samples were greater than some of the known lowest observed effect concentrations (LOECs) measured and reported in captive bird model studies. This study showed the increasing complexity of PFAS-CECs, and emphasized the importance of continuing monitoring of bioaccumulative PFAS in Great Lakes herring gulls. PMID:26318684

  8. Dissemination of Escherichia coli with CTX-M Type ESBL between Humans and Yellow-Legged Gulls in the South of France

    PubMed Central

    Gauthier-Clerc, Michel; Hernandez, Jorge; Granholm, Susanne; Kayser, Yves; Melhus, Åsa; Kahlmeter, Gunnar; Waldenström, Jonas; Johansson, Anders; Olsen, Björn

    2009-01-01

    Extended Spectrum β-Lactamase (ESBL) producing Enterobacteriaceae started to appear in the 1980s, and have since emerged as some of the most significant hospital-acquired infections with Escherichia coli and Klebsiella being main players. More than 100 different ESBL types have been described, the most widespread being the CTX-M β-lactamase enzymes (blaCTX-M genes). This study focuses on the zoonotic dissemination of ESBL bacteria, mainly CTX-M type, in the southern coastal region of France. We found that the level of general antibiotic resistance in single randomly selected E. coli isolates from wild Yellow-legged Gulls in France was high. Nearly half the isolates (47,1%) carried resistance to one or more antibiotics (in a panel of six antibiotics), and resistance to tetracycline, ampicillin and streptomycin was most widespread. In an ESBL selective screen, 9,4% of the gulls carried ESBL producing bacteria and notably, 6% of the gulls carried bacteria harboring CTX-M-1 group of ESBL enzymes, a recently introduced and yet the most common clinical CTX-M group in France. Multi locus sequence type and phylogenetic group designations were established for the ESBL isolates, revealing that birds and humans share E. coli populations. Several ESBL producing E. coli isolated from birds were identical to or clustered with isolates with human origin. Hence, wild birds pick up E. coli of human origin, and with human resistance traits, and may accordingly also act as an environmental reservoir and melting pot of bacterial resistance with a potential to re-infect human populations. PMID:19536298

  9. Long-term coral community records from Lugger Shoal on the terrigenous inner-shelf of the central Great Barrier Reef, Australia

    NASA Astrophysics Data System (ADS)

    Perry, C. T.; Smithers, S. G.; Johnson, K. G.

    2009-12-01

    Long-term (millennial timescale) records of coral community structure can be developed from the analysis of corals preserved in radiometrically dated reef cores. Here, we present such a record (based on six cores) from Lugger Shoal, a turbid zone, nearshore reef on the inner-shelf of the central Great Barrier Reef. Lugger Shoal initiated growth ~800 cal yBP. It is constructed of large in situ Porites bommies, between which a framework of coral rubble (dominated by Acropora pulchra, Montipora mollis, Galaxea fascicularis and Cyphastrea serailia) has accumulated. Reef accretion occurred under conditions of net long-term fine-grained, terrigenous sediment accumulation, and with a coral community dominated throughout by a consistent, but low diversity, suite of coral taxa. This dataset supports recent suggestions that nearshore coral communities that establish themselves under conditions that are already close to the thresholds for coral survival may be resilient to water quality deteriorations associated with human activities.

  10. Maternal condition, yolk androgens and offspring performance: a supplemental feeding experiment in the lesser black-backed gull (Larus fuscus).

    PubMed Central

    Verboven, Nanette; Monaghan, Pat; Evans, Darren M; Schwabl, Hubert; Evans, Neil; Whitelaw, Christine; Nager, Ruedi G

    2003-01-01

    It has been proposed that the maternal androgens in avian egg yolk enhance offspring fitness by accelerating growth and improving competitive ability. Because egg quality is strongly influenced by maternal condition, we predicted that females in good condition would produce high-quality eggs with relatively high androgen content. We experimentally enhanced maternal condition by supplementary feeding lesser black-backed gulls (Larus fuscus) during egg formation and compared the concentrations of androstenedione (A4), 5alpha-dihydrotestosterone (DHT) and testosterone (T) in their eggs with those in eggs laid by control females. We also measured circulating levels of T in females immediately after laying. Egg androgens could affect offspring performance directly through chick development and/or indirectly through changes in the competitive ability of a chick relative to its siblings. To avoid confounding these two routes, and to separate effects operating through the egg itself with those operating through experimental changes in parental chick rearing capacity, we fostered eggs from both maternal treatment groups singly into the nests of unmanipulated parents. Contrary to expectation, mothers with experimentally enhanced body condition laid eggs with lower levels of androgens, while exhibiting higher circulating T concentrations post-laying. Despite these lower levels of egg androgen, offspring hatched from eggs laid by mothers in good condition did not show reduced growth or survival when reared in the absence of sibling competition. Our results demonstrate that yolk androgen concentrations vary with the body condition of the female at the time of egg formation and that females in good condition reduced the yolk androgen content of their eggs without altering offspring performance. PMID:14613608

  11. Yolk testosterone affects growth and promotes individual-level consistency in behavioral lateralization of yellow-legged gull chicks.

    PubMed

    Possenti, Cristina Daniela; Romano, Andrea; Caprioli, Manuela; Rubolini, Diego; Spiezio, Caterina; Saino, Nicola; Parolini, Marco

    2016-04-01

    Behavioral lateralization is common in animals and may be expressed at the individual- and at the population-level. The ontogenetic processes that control lateralization, however, are largely unknown. Well-established sex-dependence in androgen physiology and sex-dependent variation in lateralization have led to the hypothesis that testosterone (T) has organizational effects on lateralization. The effects of T exposure in early life on lateralization can be efficiently investigated by manipulating T levels in the cleidoic eggs of birds, because the embryo is isolated from maternal and sibling physiological interference, but this approach has been adopted very rarely. In the yellow-legged gull (Larus michahellis) we increased yolk T concentration within the physiological limits and tested the effects on the direction of lateralization in two functionally fundamental behaviors (begging for parental care and escape to cover) of molecularly sexed hatchlings. We also speculated that T may intervene in regulating consistency, rather than direction of lateralization, and therefore tested if T affected the 'repeatability' of lateral preference in consecutive behavioral trials. T treatment had no effect on the direction of lateralization, but enhanced the consistency of lateral preference in escape responses. Sex did not predict lateralization. Neither behavior was lateralized at the population-level. We therefore showed for the first time in any species an effect of egg T on consistency in lateralization. The implications of the effect of T for the evolution of trade-offs in maternal allocation of egg hormones, and the evolutionary interpretations of findings from our studies on lateralization among unmanipulated birds are discussed. PMID:26836770

  12. Comparison of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers in bald eagle (Haliaeetus leucocephalus), and comparison with common eider (Somateria mollissima), glaucous-winged gull (Larus glaucescens), pigeon guillemot (Cepphus columba), and tufted puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska

    PubMed Central

    Burger, Joanna; Gochfeld, Michael

    2014-01-01

    There is an abundance of field data for levels of metals from a range of places, but relatively few from the North Pacific Ocean and Bering Sea. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from common eiders (Somateria mollissima), glaucous-winged gulls (Larus glaucescens), pigeon guillemots (Cepphus columba), tufted puffins (Fratercula cirrhata) and bald eagles (Haliaeetus leucocephalus) from the Aleutian Chain of Alaska. Our primary objective was to test the hypothesis that there are no trophic levels relationships for arsenic, cadmium, chromium, lead, manganese, mercury and selenium among these five species of birds breeding in the marine environment of the Aleutians. There were significant interspecific differences in all metal levels. As predicted bald eagles had the highest levels of arsenic, chromium, lead, and manganese, but puffins had the highest levels of selenium, and pigeon guillemot had higher levels of mercury than eagles (although the differences were not significant). Common eiders, at the lowest trophic level had the lowest levels of some metals (chromium, mercury and selenium). However, eiders had higher levels than all other species (except eagles) for arsenic, cadmium, lead, and manganese. Levels of lead were higher in breast than in wing feathers of bald eagles. Except for lead, there were no significant differences in metal levels in feathers of bald eagles nesting on Adak and Amchitka Island; lead was higher on Adak than Amchitka. Eagle chicks tended to have lower levels of manganese than older eagles. PMID:18521716

  13. Comparison of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers in bald eagle (Haliaeetus leucocephalus), and comparison with common eider (Somateria mollissima), glaucous-winged gull (Larus glaucescens), pigeon guillemot (Cepphus columba), and tufted puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska.

    PubMed

    Burger, Joanna; Gochfeld, Michael

    2009-05-01

    There is an abundance of field data for levels of metals from a range of places, but relatively few from the North Pacific Ocean and Bering Sea. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from common eiders (Somateria mollissima), glaucous-winged gulls (Larus glaucescens), pigeon guillemots (Cepphus columba), tufted puffins (Fratercula cirrhata) and bald eagles (Haliaeetus leucocephalus) from the Aleutian Chain of Alaska. Our primary objective was to test the hypothesis that there are no trophic levels relationships for arsenic, cadmium, chromium, lead, manganese, mercury and selenium among these five species of birds breeding in the marine environment of the Aleutians. There were significant interspecific differences in all metal levels. As predicted bald eagles had the highest levels of arsenic, chromium, lead, and manganese, but puffins had the highest levels of selenium, and pigeon guillemot had higher levels of mercury than eagles (although the differences were not significant). Common eiders, at the lowest trophic level had the lowest levels of some metals (chromium, mercury and selenium). However, eiders had higher levels than all other species (except eagles) for arsenic, cadmium, lead, and manganese. Levels of lead were higher in breast than in wing feathers of bald eagles. Except for lead, there were no significant differences in metal levels in feathers of bald eagles nesting on Adak and Amchitka Island; lead was higher on Adak than Amchitka. Eagle chicks tended to have lower levels of manganese than older eagles. PMID:18521716

  14. Effects of seagulls on ecosystem respiration, soil nitrogen and vegetation cover on a pristine volcanic island, Surtsey, Iceland

    NASA Astrophysics Data System (ADS)

    Sigurdsson, B. D.; Magnusson, B.

    2010-03-01

    When Surtsey rose from the North Atlantic Ocean south of Iceland in 1963, it became a unique natural laboratory on how organisms colonize volcanic islands and form ecosystems with contrasting structures and functions. In July, 2004, ecosystem respiration rate (Re), soil properties and surface cover of vascular plants were measured in 21 permanent research plots distributed among the juvenile communities of the island. The plots were divided into two main groups, inside and outside a seagull (Larus spp.) colony established on the island. Vegetation cover of the plots was strongly related to the density of gull nests. Occurrence of nests and increased vegetation cover also coincided with significant increases in Re, soil carbon, nitrogen and C:N ratio, and with significant reductions in soil pH and soil temperatures. Temperature sensitivity (Q10 value) of Re was determined as 5.3. When compared at constant temperature the Re was found to be 59 times higher within the seagull colony, similar to the highest fluxes measured in drained wetlands or agricultural fields in Iceland. The amount of soil nitrogen, mainly brought onto the island by the seagulls, was the critical factor that most influenced ecosystem fluxes and vegetation development on Surtsey. The present study shows how ecosystem activity can be enhanced by colonization of animals that transfer resources from a nearby ecosystem.

  15. Bryophyte colonization history of the virgin volcanic island Surtsey, Iceland

    NASA Astrophysics Data System (ADS)

    Ingimundardóttir, G. V.; Weibull, H.; Cronberg, N.

    2014-08-01

    The island Surtsey was formed in a volcanic eruption south of Iceland in 1963-1967 and has since then been protected and monitored by scientists. The first two moss species were found on Surtsey as early as 1967 and several new bryophyte species were discovered every year until 1973 when regular sampling ended. Systematic bryophyte inventories in a grid of 100 m × 100 m quadrats were made in 1971 and 1972: the number of observed species doubled, with 36 species found in 1971 and 72 species in 1972. Here we report results from an inventory in 2008, when every other of the grid's quadrats were searched for bryophytes. Despite lower sampling intensity than in 1972, distributional expansion and contraction of earlier colonists was revealed as well as the presence of new colonists. A total of 38 species were discovered, 15 of those were not encountered in 1972 and eight had never been reported from Surtsey before (Bryum elegans, Ceratodon heterophyllus, Didymodon rigidulus, Eurhynchium praelongum, Schistidium confertum, S. papillosum, Tortula hoppeana and T. muralis). Habitat loss due to erosion and reduced thermal activity in combination with successional vegetation changes are likely to have played a significant role in the decline of some bryophyte species which were abundant in 1972 (Leptobryum pyriforme, Schistidium apocarpum coll., Funaria hygrometrica, Philonotis spp., Pohlia spp, Schistidium strictum, Sanionia uncinata) while others have continued to thrive and expand (e.g. Schistidium maritimum, Racomitrium lanuginosum, R. ericoides, R. fasciculare and Bryum argenteum). Some species (especially Bryum spp.) benefit from the formation of new habitats, such as grassland within a gull colony, which was established in 1984. Several newcomers are rarely producing sporophytes on Iceland and are unlikely to have been dispersed by airborne spores. They are more likely to have been introduced to Surtsey by seagulls in the form of vegetative fragments or dispersal agents

  16. Bryophyte colonization history of the virgin volcanic island Surtsey, Iceland

    NASA Astrophysics Data System (ADS)

    Ingimundardóttir, G. V.; Weibull, H.; Cronberg, N.

    2014-03-01

    The island Surtsey was formed in a volcanic eruption south of Iceland in 1963-1967 and has since then been protected and monitored by scientists. The first two moss species were found on Surtsey as early as 1967 and several new bryophyte species were discovered every year until 1973 when regular sampling ended. Systematic bryophyte inventories in a grid of 100 m × 100 m quadrats were made in 1971 and 1972. The number of observed species almost doubled between years with 36 species found in 1971 and 72 species in 1972. Here we report results from an inventory in 2008, when every other of the grid's quadrats were searched for bryophytes. Despite lower sampling intensity than in 1972, distributional expansion and contraction of earlier colonists was revealed as well as presence of new colonists. A total of 38 species were discovered, 15 of those were not encountered in 1972 and eight had never been reported from Surtsey before (Bryum elegans, Ceratodon heterophyllus, Didymodon rigidulus, Eurhynchium praelongum, Schistidium confertum, S. papillosum, Tortula hoppeana and T. muralis). Habitat loss due to erosion and reduced thermal activity in combination with successional vegetation changes are likely to have played a significant role in the decline of some bryophyte species which were abundant in 1972 (Leptobryum pyriforme, Schistidium apocarpum coll., Funaria hygrometrica, Philonotis spp., Pohlia spp, Schistidium strictum, Sanionia uncinata) while others have continued to thrive and expand (e.g. Schistidium maritimum, Racomitrium lanuginosum, R. ericoides, R. fasciculare and Bryum argenteum). Some species (especially Bryum spp.) benefit from the formation of new habitats, such as grassland within a gull colony, which was established in 1984. Several newcomers are rarely producing sporophytes on Iceland and unlikely to have dispersed by airborne spores. They are more likely to have been introduced to Surtsey by seagulls in the form of vegetative fragments or dispersal

  17. Foraging movements of Audouin’s gull (Larus audouinii) in the Ebro Delta, NW Mediterranean: A preliminary satellite-tracking study

    NASA Astrophysics Data System (ADS)

    Christel, Isadora; Navarro, Joan; del Castillo, Marcos; Cama, Albert; Ferrer, Xavier

    2012-01-01

    A knowledge of the foraging strategies of marine predators is essential to understand the intrinsic factors controlling their distribution, abundance and their ecological function within the marine ecosystem. Here, we investigated for the first time the foraging movements and activity patterns of Audouin's gull Larus audouinii by using satellite-tracking data from eight breeding adults in the main colony of the species worldwide (Ebro Delta, NW Mediterranean). Tagged gulls foraged in the marine area close to the breeding colony (62% of foraging locations) and in the terrestrial area of the Ebro Delta (mainly rice fields; 38% of foraging locations). The foraging activity patterns changed significantly throughout the day; lower from dusk through the first half of the night (19-1 h; 32% of active locations) and higher during the rest of the day (1-19 h; 75.5 ± 4.3% of active locations). These results confirm the foraging plasticity of this seabird and, based on previous information about the dietary habits of this species, we hypothesize how its time-dependent activity patterns and habitat use could be associated with variations in the availability of marine food resources (e.g. diel vertical migrations of pelagic fish) and the exploitation of terrestrial resources (e.g. American crayfish Procambarus clarkii).

  18. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2001-09-14

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 1 of the project has been reservoir description and characterization. This effort has included four tasks: (1) geoscientific reservoir characterization, (2) the study of rock-fluid interactions, (3) petrophysical and engineering characterization and (4) data integration. This work was scheduled for completion in Year 1. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been initiated. Observations regarding the diagenetic processes influencing pore system development and heterogeneity in these reef and shoal reservoirs have been

  19. Dynamics of seabird colonies vulnerable to sea-level rise at French Frigate Shoals, Hawai`i

    USGS Publications Warehouse

    Reynolds, Michelle H.; Courtot, Karen N.; Krause, Crystal M.; Seavy, Nathaniel E.; Hartzell, Paula; Hatfield, Jeff S.

    2013-01-01

    and habitat creation may mitigate projected seabird population declines due to habitat loss. We predict substantial losses in seabird nesting habitat across the low-lying Hawaiian Islands by 2100 and emphasize the need to restore higher elevation seabird colonies.

  20. Influence of trophic ecology on the accumulation of dioxins and furans (PCDD/Fs), non-ortho polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in Mediterranean gulls (Larus michahellis and L. audouinii): A three-isotope approach.

    PubMed

    Roscales, Jose L; Vicente, Alba; Muñoz-Arnanz, Juan; Morales, Laura; Abad, Esteban; Aguirre, Jose I; Jiménez, Begoña

    2016-05-01

    The impact of pollution caused by severe anthropogenic pressure in the Mediterranean Sea, an important biodiversity hotspot, requires continuous research efforts. Sources of highly toxic chemicals such as Persistent Organic Pollutants (POPs) are misunderstood in representative Mediterranean species, which limits our capability to establish proper conservation strategies. In the present study, eggs of Audouin's and yellow-legged gulls (Larus audouinii and L. michahellis) were used to investigate the trophic sources, as measured by δ(13)C, δ(15)N, and δ(34)S, of legacy POPs, in particular, polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and non-ortho polychlorinated biphenyls (no-PCBs), as well as recently-regulated POPs, e.g., polybrominated diphenyl ethers (PBDEs). Special attention was paid to the usefulness of rarely-explored δ(34)S ratios in explaining POP exposure in wildlife, and δ(34)S was the isotopic ratio that best explained POP variations among gulls in most cases, thus demonstrating its usefulness for understanding POP exposure in wildlife. Significant relationships between stable isotope signatures and POP concentrations revealed increasing levels of no-PCBs and low halogenated PCDD/Fs and PBDEs in Mediterranean gulls as the consumption of marine resources increases. In contrast, highly chlorinated and brominated congeners appeared to preferentially accumulate in gulls feeding primarily on refuse from dump sites and terrestrial food webs. The use of suitable dietary tracers in the study of POPs in yellow-legged gulls revealed the importance of dump sites as a source of POPs in Mediterranean seabirds, which has not previously been reported. In contrast, the preferential accumulation through marine food webs of low chlorinated PCCD/Fs and no-PCBs, which show the highest toxic equivalents factors (TEFs), led to a significantly greater toxicological concern in Audouin's as compared to yellow-legged gulls. Audouin's gull exposure to POPs appears

  1. Ober's Island, One of the Review Islands on Rainy Lake, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Ober's Island, One of the Review Islands on Rainy Lake, bounded on the south by The Hawk Island and on the north by The Crow Island. These islands are located seven miles east of Ranier, Minnesota, three miles west of Voyageur National Park, and one mile south of the international border of the United States of America and Canada. The legal description of Mallard Island is Lot 6, Section 19, T-17-N, R-22-W, Koochiching County, Minnesota, Ranier, Koochiching County, MN

  2. Distribution and abundance of marine bird and pinniped populations within Port Foster, Deception Island, Antarctica

    NASA Astrophysics Data System (ADS)

    Kendall, Katrina A.; Ruhl, Henry A.; Wilson, Robert C.

    2003-06-01

    Seabirds and pinnipeds were surveyed during four cruises from March 1999 to November 2000 at Port Foster, Deception Island, Antarctica. Abundances and distributions of three species of pinnipeds, Arctocephalus gazella (Antarctic fur seals), Leptonychotes weddelli (Weddell seals), and Lobodon carcinophagus (crabeater seals), and 11 species of marine birds were documented within Port Foster. A. gazella was the dominant pinniped within Port Foster; its abundance has increased since the 1986/87 austral summer season. A. gazella were concentrated at the entrance to Port Foster. More pinnipeds were observed during the austral summer than during the spring. The most dominant seabird, Pygoscelis antarctica (chinstrap penguin), was concentrated along the rocky cliffs behind the beaches where A. gazella hauled out. Larus dominicanus (kelp gull) and Daption capense (cape petrel) were the most dominant flying seabirds. All other seabird species were more widely distributed around Port Foster than P. antarctica. There was no clear trend in abundances of seabirds over the study period. It is possible that the protected area of Port Foster provides refuge for vagrants of colonies along the outer periphery of the island and as a stopover point for migrating species.

  3. Channel Islands rare plants

    USGS Publications Warehouse

    McEachern, K.

    1999-01-01

    Database contains information on 65 rare plant taxa on six islands from archive searches and field surveys, including population location, size and extent 1920-1999, population and habitat conditions, census data, phenological information, associated species. USGS-BRD, Channel Islands Field Station, Ventura, CA.

  4. Pine Island Bay

    Atmospheric Science Data Center

    2013-04-16

    ... article title:  Birth of a Large Iceberg in Pine Island Bay, Antarctica     View ... iceberg (42 kilometers x 17 kilometers) broke off Pine Island Glacier, West Antarctica (75°S latitude, 102°W longitude) sometime ...

  5. Marine and Island Ecology.

    ERIC Educational Resources Information Center

    Stephens, Lawrence J.; And Others

    1988-01-01

    Describes an ecology course which provides students with an opportunity to observe aquatic and terrestrial life in the Bahamas. States that students learn scientific methodology by measuring physical and chemical aspects of the island habitats. Provides information on the island, course description and objectives, transportation, facilities, and…

  6. Basaltic island sand provenance

    SciTech Connect

    Marsaglia, K.M. . Dept. of Geological Sciences)

    1992-01-01

    The Hawaiian Islands are an ideal location to study basaltic sand provenance in that they are a series of progressively older basaltic shield volcanoes with arid to humid microclimates. Sixty-two sand samples were collected from beaches on the islands of Hawaii, Maui, Oahu and Kauai and petrographically analyzed. The major sand components are calcareous bioclasts, volcanic lithic fragments, and monomineralic grains of dense minerals and plagioclase. Proportions of these components vary from island to island, with bioclastic end members being more prevalent on older islands exhibiting well-developed fringing reef systems and volcanic end members more prevalent on younger, volcanically active islands. Climatic variations across the island of Hawaii are reflected in the percentage of weathered detritus, which is greater on the wetter, northern side of the island. The groundmass of glassy, basaltic lithics is predominantly black tachylite, with lesser brown sideromelane; microlitic and lathwork textures are more common than holohyaline vitric textures. Other common basaltic volcanic lithic fragments are holocrystalline aggregates of silt-sized pyroxene or olivine, opaque minerals and plagioclase. Sands derived from alkalic lavas are texturally and compositionally indistinguishable from sands derived from tholeiitic lavas. Although Hawaiian basaltic sands overlap in composition with magmatic arc-derived sands in terms of their relative QFL, QmPK and LmLvLs percentages, they are dissimilar in that they lack felsic components and are more enriched in lathwork volcanic lithic fragments, holocrystalline volcanic lithic fragments, and dense minerals.

  7. Back to Treasure Island

    ERIC Educational Resources Information Center

    Shriki, Atara

    2011-01-01

    In this article, the author presents the Treasure Island problem and some inquiry activities derived from the problem. Trying to find where pirates buried a treasure leads to a surprising answer, multiple solutions, and a discussion of problem solving. The Treasure Island problem is an example of an inquiry activity that can be implemented in…

  8. Island Natural Science School.

    ERIC Educational Resources Information Center

    Toronto Board of Education (Ontario).

    Prepared for students in grade six attending the Island Natural Science School, Toronto, Ontario, Canada, this booklet offers information and suggests activities in the areas of ecology, conservation, natural resources, and outdoor recreation. Introductory material describes island lore, its formation and significant features, followed by units of…

  9. Spatial and temporal comparisons of legacy and emerging flame retardants in herring gull eggs from colonies spanning the Laurentian Great Lakes of Canada and United States.

    PubMed

    Su, Guanyong; Letcher, Robert J; Moore, Jeremy N; Williams, Lisa L; Martin, Pamela A; de Solla, Shane R; Bowerman, William W

    2015-10-01

    In the Laurentian Great Lakes basin of North America, an increasing number of chemicals of emerging concern (CECs) are being investigated, including legacy and replacement flame retardants (FRs). In the present study, 14 polybrominated diphenyl ethers (PBDEs), 23 non-PBDEs halogenated FRs (NPHFRs) and 16 organophosphate ester FRs (OPE-FRs) were analyzed in 100 individual eggs collected in 2012 and 2013 and in 15 egg pools of herring gulls collected in 2012 from 20 colonies across the entire Laurentian Great Lakes basin. For CEC-FRs in eggs from all colonies, 14 PBDEs, 12 NPHFRs and 9 OPE-FRs were quantifiable in at least one of the 115 analyzed samples. The mean sum PBDE (Σ14PBDE) concentrations ranged from 244 to 657 ng/g wet weight (ww), and on average were 1-2 orders of magnitude greater than the Σ12NPHFR concentrations (13.8-35.6 ng/g ww), and 2-3 orders of magnitude greater than Σ9OPE-FR concentrations (0.31-2.14 ng/g ww). Mean Σ14PBDE and sum of syn- and anti-Dechlorane Plus isomer (Σ2DDC-CO) concentrations in eggs from colonies within Laurentian Great Lakes Areas of Concern (AOCs) were in most cases greater than in eggs from nearby colonies outside of AOCs. Comparing CEC-FR concentrations in eggs collected in 2012-2013 to those previously measured in eggs collected approximately 7 years earlier (2006 and 2008) showed that Σ7PBDE (BDE-28, -47, -100, -99, -154,-153 and -183) mean concentrations in eggs from 6 colonies were approximately 30% less than they were in eggs from the same colonies from the earlier time period, whereas 3 current-use FR (BDE-209, HBCDD and Σ2DDC-CO) concentrations were significantly greater (p<0.05) than previously measured. Between 2006 and 2013 there were significant changes in individual PBDE patterns for BDE-71, -138, -153, -203, -206 and -207. Among all of the examined CEC-FRs, concentrations of Σ4PBDE (BDE-47, -99, -100 and -153) and HBCDD in gull eggs from all colonies were greater than or comparable to their lowest

  10. The Shoal Arm Formation, north-central Newfoundland: Fe- and Mn-enriched sediments underlying black shales and flysch

    SciTech Connect

    Bruechert, V.; Delano, J.W.; Kidd, J.W.; William, S.F. . Dept. of Geological Sciences)

    1992-01-01

    The Middle Ordovician Shoal Arm Formation is located in the central volcanic belt of north-central Newfoundland and consists of a sequence of hematitic argillites overlain by grey cherts and then black shales directly underneath a late Ordovician/early Silurian flysch sequence. The hematitic argillites are enriched in Fe, Mn, Ni, Pb, and Co. Geochemically definable components within related lithologic groups were discriminated using principal component analysis and factor analysis. These procedures indicate the presence of (1) biogenic, (2) mixed detrital, (3) hydrothermal, and (4) Mn-carbonate components. The base of the hematitic part is marked by a sharp increase in the hydrothermal component, which then decreases stratigraphically upward. The Mn-carbonate component also decreases upwards, but persists up to the grey cherts. The clastic component changes from mixed mafic/pelagic clay-like detritus to Zr-, Nb- and Y-rich detritus in the top hematitic part. The grey cherts mark a transitional stage between the hematitic sediments (oxic) and the black shales (anoxic). The change to increasingly O[sub 2]-deficient conditions is explained by (a) an increase of biological productivity and related O[sub 2]-drain by C[sub org]-oxidation and/or (b) diachronous subsidence of the basin floor into a deep-water anoxic layer as a result of the loading of the basin floor by an approaching thrust stack. The similar stratigraphic sequence and geochemistry of the Middle Ordovician sediments in the Taconic Allochthon of New York State suggest that these processes also acted at other locations along the continental margin of the Iapetus Ocean. This uniformity may reflect the strong influence of the warm Middle Ordovician climate on the sediment facies or, alternatively, the control by the specific tectonic environment.

  11. Hydrologic Data and Evaluation for Model Validation Wells, MV-1, MV-2, and MV-3 near the Project Shoal Area

    SciTech Connect

    B. Lyles; P. Oberlander; D. Gillespie; D. Donithan; J. Chapman; J. Healey

    2007-02-14

    In 2006, a drilling campaign was conducted at the Project Shoal Area (PSA) to provide information for model validation, emplace long-term monitoring wells, and develop baseline geochemistry for long term hydrologic monitoring. Water levels were monitored in the vicinity of the drilling, in the existing wells HC-1 and HC-6, as well as in the newly drilled wells, MV-1, MV-2 and MV-3 and their associated piezometers. Periodic water level measurements were also made in existing wells HC-2, HC-3, HC-4, HC-5 and HC-7. A lithium bromide chemical tracer was added to drilling fluids during the installation of the monitoring and validation (MV) wells and piezometers. The zones of interest were the fractured, jointed and faulted horizons within a granitic body. These horizons generally have moderate hydraulic conductivities. As a result, the wells and their shallower piezometers required strenuous purging and development to remove introduced drilling fluids as evidenced by bromide concentrations. After airlift and surging well development procedures, the wells were pumped continuously until the bromide concentration was less then 1 milligram per liter (mg/L). Water quality samples were collected after the well development was completed. Tritium scans were preformed before other analyses to ensure the absence of high levels of radioactivity. Tritium levels were less than 2,000 pico-curies per liter. Samples were also analyzed for carbon-14 and iodine-129, stable isotopes of oxygen and hydrogen, as well as major cations and anions. Aquifer tests were performed in each MV well after the bromide concentration fell below acceptable levels. Water level data from the aquifer tests were used to compute aquifer hydraulic conductivity and transmissivity

  12. The Shark Assemblage at French Frigate Shoals Atoll, Hawai‘i: Species Composition, Abundance and Habitat Use

    PubMed Central

    Dale, Jonathan J.; Stankus, Austin M.; Burns, Michael S.; Meyer, Carl G.

    2011-01-01

    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao Mh ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289–1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling. PMID:21347321

  13. The shark assemblage at French Frigate Shoals atoll, Hawai'i: species composition, abundance and habitat use.

    PubMed

    Dale, Jonathan J; Stankus, Austin M; Burns, Michael S; Meyer, Carl G

    2011-01-01

    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao M(h) ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289-1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling. PMID:21347321

  14. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2002-09-25

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 2 of the project has been reservoir characterization, 3-D modeling and technology transfer. This effort has included six tasks: (1) the study of rockfluid interactions, (2) petrophysical and engineering characterization, (3) data integration, (4) 3-D geologic modeling, (5) 3-D reservoir simulation and (6) technology transfer. This work was scheduled for completion in Year 2. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions is near completion. Observations regarding the diagenetic processes influencing pore system development and

  15. Geographic structure and host specificity shape the community composition of symbiotic dinoflagellates in corals from the Northwestern Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Stat, Michael; Yost, Denise M.; Gates, Ruth D.

    2015-12-01

    How host-symbiont assemblages vary over space and time is fundamental to understanding the evolution and persistence of mutualistic symbioses. In this study, the diversity and geographic structure of coral-algal partnerships across the remote Northwestern Hawaiian Islands archipelago was investigated. The diversity of symbionts in the dinoflagellate genus Symbiodinium was characterised using the ribosomal internal transcribed spacer 2 (ITS2) gene in corals sampled at ten reef locations across the Northwestern Hawaiian Islands. Symbiodinium diversity was reported using operational taxonomic units and the distribution of Symbiodinium across the island archipelago investigated for evidence of geographic structure using permutational MANOVA. A 97 % sequence similarity of the ITS2 gene for characterising Symbiodinium diversity was supported by phylogenetic and ecological data. Four of the nine Symbiodinium evolutionary lineages (clades A, C, D, and G) were identified from 16 coral species at French Frigate Shoals, and host specificity was a dominant feature in the symbiotic assemblages at this location. Significant structure in the diversity of Symbiodinium was also found across the archipelago in the three coral species investigated. The latitudinal gradient and subsequent variation in abiotic conditions (particularly sea surface temperature dynamics) across the Northwestern Hawaiian Islands encompasses an environmental range that decouples the stability of host-symbiont assemblages across the archipelago. This suggests that local adaptation to prevailing environmental conditions by at least one partner in coral-algal mutualism occurs prior to the selection pressures associated with the maintenance of a symbiotic state.

  16. Erosion and deterioration of the Isles Dernieres Barrier Island Arc, Louisiana, U.S.A.: 1853 to 1988

    USGS Publications Warehouse

    McBride, Randolph A.; Penland, Shea; Jaffe, Bruce E.; Williams, S. Jeffress; Sallenger, Asbury H., Jr.; Westphal, Karen A.

    1989-01-01

    Using cartographic and aerial photography data from the years 1853, 1890, 1934, 1956, 1978, 1984, and 1988, shoreline change maps of the Isles Dernieres barrier island arc were constructed. These data were accurately superimposed, using a computer mapping system, which removed projection, datum, scale, and other cartographic inconsistencies. Linear, areal, and perimeter measurements indicate that the Isles Dernieres are suffering rapid rates of coastal erosion, land loss, and breakup. Bayside and gulfside erosion, in combination with sediment shortage and subsidence, have caused the Isles Dernieres to narrow through time. In addition, the core of the barrier island arc does not migrate landward and instead, breaks up in place as a result of inlet breaching and development. This is in contrast to other models of landward barrier island migration during transgression. If these trends continue, the Isles Dernieres will likely evolve into a subaqueous inner-shelf shoal by the early 21st century. Loss of the Isles Dernieres barrier island arc will severely impact the Terrebonne parish estuary, resulting in decreased environmental quality and increased public risk from storms and hurricanes.

  17. Ober's Island: The Mallard Ober's Island, One of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Ober's Island: The Mallard - Ober's Island, One of the Review Islands on Rainy Lake, bounded on the south by The Hawk Island and on the north by The Crow Island. These islands are located seven miles east of Ranier, Minnesota, three miles west of Voyageur National Park, and one mile south of the international border of the United States of America and Canada. The legal description of Mallard Island is Lot 6, Section 19, T-17-N, R-22-W, Koochiching County, Minnesota, Ranier, Koochiching County, MN

  18. Spatio-temporal trends and monitoring design of perfluoroalkyl acids in the eggs of gull (Larid) species from across Canada and parts of the United States.

    PubMed

    Gewurtz, Sarah B; Martin, Pamela A; Letcher, Robert J; Burgess, Neil M; Champoux, Louise; Elliott, John E; Weseloh, D V Chip

    2016-09-15

    A large spatial dataset of perfluoroalkyl acid (PFAA) concentrations in eggs of herring gulls (Larus argentatus or congeneric species) collected from late April to early June between 2009 and 2014 from 28 colonies across Canada and parts of the Unites States was used to evaluate location-specific patterns in chemical concentrations and to generate hypotheses on the major sources affecting PFAA distributions. The highly bioaccumulative perfluorooctane sulfonic acid (PFOS) as well as other perfluoroalkyl sulfonic acids (PFSAs) showed the greatest concentrations in eggs from the lower Great Lakes of southern Ontario as well as from the St. Lawrence River. Despite the 2000 to 2002 phase-out of PFOS and related C8 chemistry by the major manufacturer at the time, ongoing losses from consumer products during use and disposal in urban/industrial locations continue to be major sources to the environment and are influencing the spatial trends of PFOS in Canada. In comparison to PFOS, perfluoroalkyl carboxylic acids (PFCAs) were not as concentrated in eggs in close proximity to urbanized/industrialized centers, but had surprisingly elevated levels in relatively remote regions such as Great Slave Lake, NT and East Bay in Hudson Bay, NU. The present results support the hypothesis that atmospheric transport and degradation of precursor chemicals, such as the fluorotelomer alcohols 8:2 FTOH and 10:2 FTOH, are influencing the spatial trends of PFCAs in Canada. A power analysis conducted on a representative urbanized/industrialized colony in the Toronto Harbour, ON, and a relatively remote colony in Lake Superior, emphasized the importance of consistent and long-term data collection in order to detect the anticipated changes in PFAA concentrations in Canadian gull eggs. PMID:27183458

  19. Liquid chromatography-electrospray-tandem mass spectrometry method for determination of organophosphate diesters in biotic samples including Great Lakes herring gull plasma.

    PubMed

    Su, Guanyong; Greaves, Alana K; Gauthier, Lewis; Letcher, Robert J

    2014-12-29

    Environmentally relevant organophosphate (OP) triester flame retardants are known to degrade to OP diester phosphoric acids. In this study, a quantitatively sensitive method was developed for OP diesters in biological samples of varying complexity, bovine serum, chicken egg homogenate and pork liver. Fortified with 1ng or 10ng each of the six OP diester and six OP triester standards, samples were extracted by accelerated solvent extraction that completely separated OP diesters and triesters. OP diester fractions were cleaned up using weak anion exchange solid phase extraction and eluted with high ionic strength ammonium acetate buffer. Optimal analysis of chlorinated OP diesters was via decamethonium hydroxide dicationic reagent derivatization and by LC-ESI(+)-MS/MS, and for all non-chlorinated OP diesters by non-derivatized LC-ESI(-)-MS/MS. Except for derivatization LC-ESI(+)-MS/MS analysis of liver, at the 10ng spiking level for the three matrices, recovery efficiencies, matrix effects and method limits of quantification (MLOQs) of OP diesters ranged from 55-116%, 92-119%, and 0.02-0.31ng/g wet weight (ww) respectively. Plasma samples of n=6 herring gulls (2010, Chantry Is., Laurentian Great Lakes) contained triphenyl phosphate and tris(1-3-dichloro-2-propyl) phosphate ranging from 1.3 to 4.0ng/g ww and gulls. PMID:25476687

  20. Cognitive Constraints and Island Effects

    ERIC Educational Resources Information Center

    Hofmeister, Philip; Sag, Ivan A.

    2010-01-01

    Competence-based theories of island effects play a central role in generative grammar, yet the graded nature of many syntactic islands has never been properly accounted for. Categorical syntactic accounts of island effects have persisted in spite of a wealth of data suggesting that island effects are not categorical in nature and that…

  1. Belcher Islands, Canada

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Belcher Islands are an archipelago in Hudson Bay in Canada, belonging to the territory of Nunavit. The hamlet of Sanikiluaq is on the north coast of Flaherty Island. Over 1500 islands make up the archipelago. The folded sedimentary and volcanic rocks making up the islands are Proterozoic in age between 0.5 and 2.5 billion years old.

    The image mosaic was acquired 18 September 2006, covers an area of 45.7 x 113.3 km, and is located near 56.1 degrees north latitude, 79.4 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  2. Lost island found

    NASA Astrophysics Data System (ADS)

    An abandoned ll-by-5-km kidney-shaped chunk of freshwater ice, used as a research station for 25 years, was rediscovered after the National Oceanic and Atmospheric Administration (NOAA) lost track of the island for 6 months. The recent find may foreshadow another loss, however: The island is drifting through the Greenland Sea and into the North Atlantic where it should melt within several months and d u m p its cargo of oil drums, equipment, and a wrecked plane into the ocean.Known as Fletcher's Ice Island—after Joseph O. Fletcher, a member of the first team of researchers to inhabit the island and a recently retired NOAA climate researcher—the ice chunk has already melted to a third of its original 49 m thickness. A pilot flying over the area to measure annual pollution buildup in the Arctic located the drifting island 242 km from the North Pole near the International Date Line.

  3. The Island Approach.

    ERIC Educational Resources Information Center

    Schroder, Peter C.

    1994-01-01

    Proposes the study of islands to develop a method of integrating sustainable development with sound resource management that can be extrapolated to more complex, highly populated continental coastal areas. (MDH)

  4. Island Watershed Activity.

    ERIC Educational Resources Information Center

    Benson, Rod

    2003-01-01

    Describes a 90-minute "Island Watershed" activity to help earth science students understand the concept of the water cycle. Introduces a surface waters unit appropriate for students in grades 7-10. Includes watershed project guidelines. (Author/KHR)

  5. Small islands adrift

    NASA Astrophysics Data System (ADS)

    Petherick, Anna

    2015-07-01

    With the charismatic former president of the Maldives, Mohamed Nasheed, behind bars on a widely derided terrorism charge, Anna Petherick asks whether small island states can really make themselves heard in Paris.

  6. Analysis of borehole-radar reflection logs from selected HC boreholes at the Project Shoal area, Churchill County, Nevada

    USGS Publications Warehouse

    Lane, J.W., Jr.; Joesten, P.K.; Pohll, G.M.; Mihevic, Todd

    2001-01-01

    Single-hole borehole-radar reflection logs were collected and interpreted in support of a study to characterize ground-water flow and transport at the Project Shoal Area (PSA) in Churchill County, Nevada. Radar logging was conducted in six boreholes using 60-MHz omni-directional electric-dipole antennas and a 60-MHz magnetic-dipole directional receiving antenna.Radar data from five boreholes were interpreted to identify the location, orientation, estimated length, and spatial continuity of planar reflectors present in the logs. The overall quality of the radar data is marginal and ranges from very poor to good. Twenty-seven reflectors were interpreted from the directional radar reflection logs. Although the range of orientation interpreted for the reflectors is large, a significant number of reflectors strike northeast-southwest and east-west to slightly northwest-southeast. Reflectors are moderate to steeply dipping and reflector length ranged from less than 7 m to more than 133 m.Qualitative scores were assigned to each reflector to provide a sense of the spatial continuity of the reflector and the characteristics of the field data relative to an ideal planar reflector (orientation score). The overall orientation scores are low, which reflects the general data quality, but also indicates that the properties of most reflectors depart from the ideal planar case. The low scores are consistent with reflections from fracture zones that contain numerous, closely spaced, sub-parallel fractures.Interpretation of borehole-radar direct-wave velocity and amplitude logs identified several characteristics of the logged boreholes: (1) low-velocity zones correlate with decreased direct-wave amplitude, indicating the presence of fracture zones; (2) direct-wave amplitude increases with depth in three of the boreholes, suggesting an increase in electrical resistivity with depth resulting from changes in mineral assemblage or from a decrease in the specific conductance of ground

  7. Melville Island, Australia

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Melville Island, just off the coast of Darwin, Northern Territory, Australia (11.5S, 131.0E) is a sparsely inhabited tropical island with heavy woodland concentrations. The widespread and prominant smoke plumes were most likely set to renew pasture under open canopy woodland. Soil erosion is almost non- existant as can be seen by the clear and clean river flow. The offshore sediments are coastal current borne deposits from King Sound to the west.

  8. Survival, transport, and sources of fecal bacteria in streams and survival in land-applied poultry litter in the upper Shoal Creek basin, southwestern Missouri, 2001-2002

    USGS Publications Warehouse

    Schumacher, John G.

    2003-01-01

    Densities of fecal coliform bacteria along a 5.7-mi (mile) reach of Shoal Creek extending upstream from State Highway 97 (site 3) to State Highway W (site 2) and in two tributaries along this reach exceeded the Missouri Department of Natural Resources (MDNR) standard of 200 col/100 mL (colonies per 100 milliliters) for whole-body contact recreation. A combination of techniques was used in this report to provide information on the source, transport, and survival of fecal bacteria along this reach of Shoal Creek. Results of water-quality samples collected during dye-trace and seepage studies indicated that at summer low base-flow conditions, pastured cattle likely were a substantial source of fecal bacteria in Shoal Creek at the MDNR monitoring site (site 3) at State Highway 97. Using repeat element Polymerase Chain Reaction (rep-PCR), cattle were the presumptive source of about 50 percent of the Escherichia coli (E. coli) isolates in water samples from site 3. Cattle, horses, and humans were the most common presumptive source of E. coli isolates at sites further upstream. Poultry was identified by rep-PCR as a major source of E. coli in Pogue Creek, a tributary in the upper part of the study area. Results of the rep-PCR were in general agreement with the detection and distribution of trace concentrations of organic compounds commonly associated with human wastewater, such as caffeine, the antimicrobial agent triclosan, and the pharmaceutical compounds acetaminophen and thiabendazole (a common cattle anthelmintic). Significant inputs of fecal bacteria to Shoal Creek occurred along a 1.6-mi reach of Shoal Creek immediately upstream from site 3. During a 36-hour period in July 2001, average densities of fecal coliform and E. coli bacteria increased from less than or equal to 500 col/100 mL upstream from this stream reach (sample site 2c) to 2,100 and 1,400 col/100 mL, respectively, at the MDNR sampling site. Fecal bacteria densities exhibited diurnal variability at all

  9. The Role of Backbarrier Filling in the Evolution of a Barrier Island System

    NASA Astrophysics Data System (ADS)

    Hein, C. J.; Fitzgerald, D. M.; Stone, B. D.; Carruthers, E.; Gontz, A. M.

    2009-12-01

    inlet southward. GPR profiles reveal that the inlet sequence contains conformable sets of southerly dipping reflectors punctuated by sharp truncation surfaces, cut and fill structures and smaller packets of northerly dipping reflectors. These large-scale structures are evidence of inlet migration, ebb-delta breaching, onshore bar migration, channel shoaling, and closure of a tidal inlet. Discovery of the paleo-inlet within the Plum Island lithosome illuminates the larger process of backbarrier infilling and its effect barrier and tidal inlet morphodynamics. Sediment influx to the backbarrier from nearby river systems and the offshore led to bay sedimentation, formation of tidal flats and marshes, and a vast reduction in the bay tidal prism. Ultimately the inlet closed by a southerly building spit.

  10. Island-arc carbonates: characterization and recognition in the ancient geologic record

    NASA Astrophysics Data System (ADS)

    Soja, C. M.

    1996-10-01

    Carbonates of island-arc origin that are preserved in Paleozoic-Mesozoic terranes of the North American Cordillera exhibit a distinctive suite of paleontologic and lithologic features and share a fundamental similarity with limestones forming in modern volcanic arcs. This study provides the first detailed synthesis of carbonate depositional systems in island arcs and documents primary sedimentary constituents based on facies relationships and faunal communities. Models are developed that show patterns in the long-term evolution of shallow marine organisms and the construction, evolution, and demise of carbonate platforms in island arcs. A suite of criteria is identified that may be used to differentiate island-arc carbonates from limestones that accumulated in other platform settings. Biogeographic isolation, prolonged subsidence, steep submarine slopes and tectonic instability of volcanic edifices contribute to the development of relatively high levels of species endemism, impoverished normal marine faunas, complex provincial affinities, and relict biotas in limestones that are characterized by exceptionally thick platform and periplatform sequences, fringing and barrier reefs at the shelf margin, extensive lagoonal deposits and rapid lateral and vertical facies changes. Although destructive tectonic and geologic processes in island arcs may hinder determining the original size and extent of the carbonate platform, and particular facies types may not be represented (e.g., fringing and barrier reefs may be replaced by sand shoals at the platform, margin), many characteristics have potential value for identifying carbonates of island-arc origin in the ancient rock record. Apart from being associated with calc-alkaline volcanic and volcaniclastic assemblages, the most valuable suite of features for recognizing island-arc carbonates is marine biotas that exhibit elevated levels of endemism and mixed paleobiogeographic affinities, extraordinary thicknesses of platform

  11. Early Silurian (Llandoverian) Leask Point and Charlton Bay bioherms, Manitoulin Island, Ontario, Canada

    SciTech Connect

    Mielczarek, W.; Copper, P.

    1986-08-01

    About 300 bioherms are known in the Llandoverian Manitoulin Formation of eastern Manitoulin Island. In the South Bay area, the large Leask Piont bioherm and Charlton Bay patch-reef complex lack a distinct skeletal growth framework. Bioherms consist of mudstone and wackestone, with isolated lenses of bafflestone, boundstone, floatstone. Fossils are scarce, but crinozoans and bryozoans comprise about 90% of the bioclasts. Other fauna include stromatoporoids, corals, brachiopods, gastropods, trilobites, and probable algae (algae are difficult to identify and may have played a significant role). Faunal ratios remained relatively constant during mound growth. Soft substrates with sedimentation rates of a few millimeters per year are suggested by bedding type and morphologic dominance of lamellar and tabular corals and stromatoporoids. An increased sedimentation rate, resulting from shoaling, is indicated by more overturned, broadly conical corals in the upper parts of the mounds. Shoaling may be responsible for cessation of mound growth. Lithoclasts are more common in the upper parts of the mounds. They formed when semiconsolidated muds were disturbed and redeposited during storms. Megarippled interreef surface areas, largely devoid of coral growth, indicate mud instability at Charlton Bay. Lack of suitable stable substrates may have hampered coral development. Dolomitization was postdepositional. The diagenetic sequence occurred in three stages: 1)selective pyritization and silicification, formation of an early muddy dolomite replacing the mud fraction of the dolostone, lithification and formation of rare calcite cement and neomorphic syntaxial rims; 2)clear, coarse dolomite replacing pore-filling calcite cement, syntaxial rims, and unaltered macrofossils, stylolitization, grain-to-grain dissolution; and 3)a late dolomite found mainly as fine rhombs in stylolites, solution seams, and intraskeletal pore space.

  12. Human-Induced Long-Term Shifts in Gull Diet from Marine to Terrestrial Sources in North America's Coastal Pacific: More Evidence from More Isotopes (δ2H, δ34S).

    PubMed

    Hobson, Keith A; Blight, Louise K; Arcese, Peter

    2015-09-15

    Measurements of naturally occurring stable isotopes in tissues of seabirds and their prey are a powerful tool for investigating long-term changes in marine foodwebs. Recent isotopic (δ(15)N, δ(13)C) evidence from feathers of Glaucous-winged Gulls (Larus glaucescens) has shown that over the last 150 years, this species shifted from a midtrophic marine diet to one including lower trophic marine prey and/or more terrestrial or freshwater foods. However, long-term isotopic patterns of δ(15)N and δ(13)C cannot distinguish between the relative importance of lower trophic-level marine foods and terrestrial sources. We examined 48 feather stable-hydrogen (δ(2)H) and -sulfur (δ(34)S) isotope values from this same 150-year feather set and found additional isotopic evidence supporting the hypothesis that gulls shifted to terrestrial and/or freshwater prey. Mean feather δ(2)H and δ(34)S values (± SD) declined from the earliest period (1860-1915; n = 12) from -2.5 ± 21.4 ‰ and 18.9 ± 2.7 ‰, respectively, to -35.5 ± 15.5 ‰ and 14.8 ± 2.4 ‰, respectively, for the period 1980-2009 (n = 12). We estimated a shift of ∼ 30% increase in dependence on terrestrial/freshwater sources. These results are consistent with the hypothesis that gulls increased terrestrial food inputs in response to declining forage fish availability. PMID:26302356

  13. Heron Island, Australia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Heron Island is located at the sourthern end of Australia's 2,050 km-long Great Barrier Reef. Surrounded by coral reef and home to over 1000 species of fish, scuba divers and scientists alike are drawn to the island's resort and research station. The true-color image above was taken by Space Imaging's Ikonos satellite with a resolution of 4 meters per pixel-high enough to see individual boats tied up at the small marina. The narrow channel leading from the marina to the ocean was blasted and dredged decades ago, before the island became a national park. Since then the Australian government has implemented conservation measures, such as limiting the number of tourists and removing or recycling, instead of incinerating, all trash. One of the applications of remote sensing data from Ikonos is environmental monitoring, including studies of coral reef health. For more information about the island, read Heron Island. Image by Robert Simmon, based on data copyright Space Imaging

  14. Maintenance of biodiversity on islands.

    PubMed

    Chisholm, Ryan A; Fung, Tak; Chimalakonda, Deepthi; O'Dwyer, James P

    2016-04-27

    MacArthur and Wilson's theory of island biogeography predicts that island species richness should increase with island area. This prediction generally holds among large islands, but among small islands species richness often varies independently of island area, producing the so-called 'small-island effect' and an overall biphasic species-area relationship (SAR). Here, we develop a unified theory that explains the biphasic island SAR. Our theory's key postulate is that as island area increases, the total number of immigrants increases faster than niche diversity. A parsimonious mechanistic model approximating these processes reproduces a biphasic SAR and provides excellent fits to 100 archipelago datasets. In the light of our theory, the biphasic island SAR can be interpreted as arising from a transition from a niche-structured regime on small islands to a colonization-extinction balance regime on large islands. The first regime is characteristic of classic deterministic niche theories; the second regime is characteristic of stochastic theories including the theory of island biogeography and neutral theory. The data furthermore confirm our theory's key prediction that the transition between the two SAR regimes should occur at smaller areas, where immigration is stronger (i.e. for taxa that are better dispersers and for archipelagos that are less isolated). PMID:27122558

  15. 15 CFR Appendix B to Subpart G of... - Marine Reserve Boundaries

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ....16670 °W 4 33.84700 °N 120.10830 °W 5 33.84000 °N 120.10830 °W B.4. Gull Island (Santa Cruz Island) Marine Reserve The Gull Island Marine Reserve (Gull Island) boundary is defined by the 3 nmi State boundary, the coordinates provided in Table B-4, and the following textual description. The Gull...

  16. Archaeoastronomy of Easter Island

    NASA Astrophysics Data System (ADS)

    Edwards, Edmundo

    Astronomer priests or "skywatchers" on Easter Island lived in stone towers that were used as observatories and built stone markers in the periphery that indicated the heliacal rising of certain stars that served to indicate the arrival of marine birds, turtles, the offshore fishing season, and times for planting and harvest. Petroglyphs related to such sites depict outriggers, fishhooks, pelagic fish, and turtles and supposedly represented a star map. In this chapter, we analyze a set of such skywatchers dwellings, and stone markers located upon the North coast of Easter Island that have astronomic orientations, its related petroglyphs, and the relations between these directions with their yearly activities and their ritual calendar.

  17. Sakhalin Island terrain intelligence

    USGS Publications Warehouse

    U.S. Geological Survey Military Geology Branch

    1943-01-01

    This folio of maps and explanatory tables outlines the principal terrain features of Sakhalin Island. Each map and table is devoted to a specialized set of problems; together they cover the subjects of terrain appreciation, climate, rivers, water supply, construction materials, suitability for roads, suitability for airfields, fuels and other mineral resources, and geology. In most cases, the map of the island is divided into two parts: N. of latitude 50° N., Russian Sakhalin, and south of latitude 50° N., Japanese Sakhalin or Karafuto. These maps and data were compiled by the United States Geological Survey during the period from March to September, 1943.

  18. Long Island Solar Farm

    SciTech Connect

    Anders, R.

    2013-05-01

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  19. Controlling summer heat islands: Proceedings

    SciTech Connect

    Garbesi, K.; Akbari, H.; Martien, P.

    1989-11-01

    A workshop was held on the energy and pollution implications of summertime urban heat islands and the potential to control them. The presentations, papers, and discussions fell into four broad categories: (1) the potential to conserve energy, reduce atmospheric pollution, and slow global warming by reducing summer heat islands; (2) the use of computer models to understand and simulate the heat island phenomenon; (3) measurements of heat islands; and (4) the design and implementation of heat island mitigation strategies. On the afternoon of the second day of the workshop, the participants divided into three workgroups. Group 1 discussed research needs to better quantify the effect of heat island mitigation on energy use. Group 2 discussed future research on the characterization and modeling of heat islands. And Group 3 discussed the development of a manual that would present to policy makers our current knowledge of techniques to mitigate heat islands and thereby save energy. This Proceedings documents the presentations and outcome of the Workshop.

  20. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2004-02-25

    The University of Alabama, in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company, has undertaken an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary goal of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. Geoscientific reservoir property, geophysical seismic attribute, petrophysical property, and engineering property characterization has shown that reef (thrombolite) and shoal reservoir lithofacies developed on the flanks of high-relief crystalline basement paleohighs (Vocation Field example) and on the crest and flanks of low-relief crystalline basement paleohighs (Appleton Field example). The reef thrombolite lithofacies have higher reservoir quality than the shoal lithofacies due to overall higher permeabilities and greater interconnectivity. Thrombolite dolostone flow units, which are dominated by dolomite intercrystalline and vuggy pores, are characterized by a pore system comprised of a higher percentage of large-sized pores and larger pore throats. Rock-fluid interactions (diagenesis) studies have shown that although the primary control on

  1. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2003-09-25

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling that utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 3 of the project has been reservoir characterization, 3-D modeling, testing of the geologic-engineering model, and technology transfer. This effort has included six tasks: (1) the study of seismic attributes, (2) petrophysical characterization, (3) data integration, (4) the building of the geologic-engineering model, (5) the testing of the geologic-engineering model and (6) technology transfer. This work was scheduled for completion in Year 3. Progress on the project is as follows: geoscientific reservoir characterization is completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been completed. Observations regarding the diagenetic

  2. Safety Evaluation Report for the Tennessee Valley Authority's Plan to Decommission its Low-Level Radioactive Waste Burial Site at Muscle Shoals, Alabama

    SciTech Connect

    Gant, K.S.; Kettelle, R.H.

    1998-11-01

    From 1966 to 1981, the Tennessee Valley Authority (TVA) operated a burial site, licensed under the former 10 CFR 20.304, for low-level radioactive waste on its Muscle Shoals, Alabama, reservation. TVA submitted a decommissioning plan for the burial site and requested approval for unrestricted use of the site. The Nuclear Regulatory Commission requested Oak Ridge National Laboratory (ORNL) to evaluate this plan to determine if the site meets the radiological requirements for unrestricted use as specified in 10 CFR 20.1402; that is, an average member of the critical group would not receive more than 25 mrem/y from residual radioactivity at the TVA Low-Level Radioactive Waste Burial Site and the radioactivity has been reduced to levels as low as reasonably achievable (ALARA).

  3. Orgin and significance of geochemical variability among oils and gas-condensates in the Tiger Shoal Field, northern Gulf of Mexico

    SciTech Connect

    Kelley, P.A.; Imbus, S.W.; McKeever, S.R.

    1995-12-31

    Geochemical data placed in geological context is key to understanding the processes controlling the variability of oils and gas-condensates in the Tiger Shoal Field, northern Gulf of Mexico. Thermal maturity at generation and phase partitioning are the principal processes accounting for variability in the bulk and molecular properties of the oils and gas-condensates. Quantification of the extent that these processes altered the oils and gas-condensates between fault blocks and among individual sands permits: (1) documentation of the most effective migration conduits, (2) inference of deeper or shallower pay zones, (3) and assessment of vertical and lateral fluid connectivity. Calibration of bulk to molecular properties will permit rapid assessment of the type and extent of alteration using basic parameters such as API gravity and gas oil ratio (GOR). Upon mass balancing with initial reserves data, a detailed risking scheme for remaining prospects within the field can be formulated.

  4. HEAT ISLAND REDUCTION STRATEGIES GUIDEBOOK

    EPA Science Inventory

    This heat island reduction strategies guidebook provides an overview of urban heat islands and steps communities can take to reduce them. In particular, this guidebook provides background basics and answers the questions: “What is a heat island?” “What are its impacts?" "What ar...

  5. Seasonal Hypoxia on the Shelf and Shoaling of the Permanent Oxycline in the Open Sea: Two Faces of the Black Sea Deoxygenation

    NASA Astrophysics Data System (ADS)

    Capet, Arthur; Stanev, Emil; Beckers, Jean-Marie; Grégoire, Marilaure

    2016-04-01

    The Black Sea is highly sensitive to external forcings and constitutes a natural laboratory to study the interplays of atmospheric warming and eutrophication on deoxygenation dynamics. Two decades of eutrophication were followed by a sudden reduction of nutrient loads in the late 1980s. Warm and cold air temperature cycles (5-10 years) follow atmospheric oscillation patterns, with a clear warming affecting the recent decades. On the Black Sea north western shelf (<120m), which receives more that 3/4 of the river runoff, seasonal hypoxia occurs when summer stratification prevents atmospheric fluxes to compensate for the respiration of organic matter accumulated in the lower water column and the sediments. A former multidecadal 3D model study (1) indicated that current monitoring do not provide a satisfactorily assessment of hypoxia, (2) revealed the inertia due to the benthic accumulation of organic matter during eutrophication period and (3) estimated the nutrient reduction effort required in adaptation to atmospheric warming. In the open basin (120-2000m), the permanent interface between anoxic and oxic waters is subject to vertical migration as the ventilation ensured by dense water formation balances the respiration of sinking organic matter. The analysis of R/V casts and ARGO profiles revealed that the oxycline has shoaled from 140 to 90m between 1955 and present years, while the basin lost 36 % of its oxygen inventory. While the interactions between seasonal hypoxia on the shelf and the shoaling oxic interface in the open basin are not clear, both dynamics will face atmospheric warming and new industrial development of the lower danube watershed. We discuss the specific monitoring and modelling efforts required to assess the environmental and economical threat cast by further deoxygenation in the Black Sea.

  6. Fluid Management Plan for Corrective Action Unit 447: Project Shoal Area, Subsurface, Nevada, Rev. No.: 1 with ROTC 1 and Errata Sheet

    SciTech Connect

    Tim Echelard

    2006-01-01

    The U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) initiated the Offsites Project to characterize the risk posed to human health and the environment as a result of testing at formerly used nuclear sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The scope of this Fluid Management Plan (FMP) is to support the subsurface investigation at the Project Shoal Area (PSA) Corrective Action Unit (CAU) 447, Shoal-Subsurface, Nevada, in accordance with the ''Federal Facility Agreement and Consent Order'' (FFACO) (1996). Corrective Action Unit 447 is located in the Sand Spring Range, south of Highway 50, about 39 miles southeast of Fallon, Nevada. (Figure 1-1). This FMP will be used at the PSA in lieu of an individual discharge permit for each well or a general water pollution control permit for management of all fluids produced during the drilling, construction, development, testing, experimentation, and/or sampling of wells conducted by the Offsites Project. The FMP provides guidance for the management of fluids generated during investigation activities and provides the standards by which fluids may be discharged on site. Although the Nevada Division of Environmental Protection (NDEP), Bureau of Federal Facilities (BoFF) is not a signatory to this FMP, it is involved in the negotiation of the contents of this plan and approves the conditions contained within. The major elements of this FMP include: (1) establishment of a well-site operations strategy; (2) site design/layout; (3) monitoring of contamination indicators (monitoring program); (4) sump characterization (sump sampling program); (5) fluid management decision criteria and fluid disposition; and (6) reporting requirements.

  7. Island Ecology in Bermuda.

    ERIC Educational Resources Information Center

    Wulff, Barry L.; And Others

    1981-01-01

    Reports on an island ecology course offered by Eastern Connecticut State College providing opportunities for students to study the ecology and natural history of organisms found in a variety of subtropical habitats in Bermuda. Explains student selection criteria, trip preparation, evaluation criteria, daily programs, and habitats studied on the…

  8. Christmas Island birds returning

    NASA Astrophysics Data System (ADS)

    Six months after their mass exodus, birds are beginning to return to Christmas Island. Roughly 17 million birds, almost the entire adult bird population, either perished or fled their mid-Pacific atoll home last autumn, leaving behind thousands of nestlings to starve (Eos, April 5, 1983, p. 131). It is believed that the strong El Niño altered the ecology of the surrounding waters and forced the birds to flee. Christmas Island is the world's largest coral atoll.“Ocean and atmosphere scientists are unsure of future directions for the El Niño conditions and cannot now predict what will happen to the birds in the coming months,” said Ralph W. Schreiber, curator of ornithology at the Natural History Museum of Los Angeles County in California. Heisthe ornithologist who discovered the disappearance. “The recovery of the bird populations depends on the food supply in the waters surrounding the island.” The island's birds feed exclusively on small fish and squid.

  9. Hawaii's Sugar Islands.

    ERIC Educational Resources Information Center

    Hawaiian Sugar Planters' Association, Aiea, HI.

    A warm and sunny subtropical climate helps make Hawaii an important sugar producer. History records that sugarcane was already present when Captain James Cook discovered the islands in 1778, and that the first successful sugarcane plantation was started in 1835 by Ladd and Company at Koloa. The first recorded export of Hawaiian sugar was in 1837,…

  10. Kiritimati, Kiribati (Christmas Island)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Pronounced 'Ki-ris-mas,' Kiritimati Island has a large infilled lagoon that gives it the largest land area (125 square miles, 321 square km) of any atoll in the world. Captain Cook named the atoll Christmas Island when he arrived on Christmas Eve in 1777. Used for nuclear testing in the 1950s and 1960s, the island is now valued for its marine and wildlife resources. It is particularly important as a seabird nesting site-with an estimated 6 million birds using or breeding on the island, including several million Sooty Terns. Rainfall on Kiritimati is linked to El Nino patterns, with long droughts experienced between the wetter El Nino years. This image is based on a mosaic of four digital photographs taken on 16 January 2002 from the Space Station Alpha as part of the Crew Earth Observations Project. The underlying data have 10 meter spatial resolution. Coral reefs are one of the areas selected as a scientific theme for this project (see also the recent Earth Observatory article, Mapping the Decline of Coral Reefs. The mosaic, based on images ISS004-ESC-6249 to 6252, was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  11. The Flores Island tsunamis

    NASA Astrophysics Data System (ADS)

    Yeh, Harry; Imamura, Fumihiko; Synolakis, Costas; Tsuji, Yoshinobu; Liu, Philip; Shi, Shaozhong

    On December 12, 1992, at 5:30 A.M. GMT, an earthquake of magnitude Ms 7.5 struck the eastern region of Flores Island, Indonesia (Figure 1), a volcanic island located just at the transition between the Sunda and Banda Island arc systems. The local newspaper reported that 25-m high tsunamis struck the town of Maumere, causing substantial casualties and property damage. On December 16, television reports broadcast in Japan via satellite reported that 1000 people had been killed in Maumere and twothirds of the population of Babi Island had been swept away by the tsunamis.The current toll of the Flores earthquake is 2080 deaths and 2144 injuries, approximately 50% of which are attributed to the tsunamis. A tsunami survey plan was initiated within 3 days of the earthquake, and a cooperative international survey team was formed with four scientists from Indonesia, nine from Japan, three from the United States, one from the United Kingdom, and one from Korea.

  12. Multidecadal shoreline changes of atoll islands in the Marshall Islands

    NASA Astrophysics Data System (ADS)

    Ford, M.

    2012-12-01

    Atoll islands are considered highly vulnerable to the impacts of continued sea level rise. One of the most commonly predicted outcomes of continued sea level rise is widespread and chronic shoreline erosion. Despite the widespread implications of predicted erosion, the decadal scale changes of atoll island shorelines are poorly resolved. The Marshall Islands is one of only four countries where the majority of inhabited land is comprised of reef and atoll islands. Consisting of 29 atolls and 5 mid-ocean reef islands, the Marshall Islands are considered highly vulnerable to the impacts of sea level rise. A detailed analysis of shoreline change on over 300 islands on 10 atolls was undertaken using historic aerial photos (1945-1978) and modern high resolution satellite imagery (2004-2012). Results highlight the complex and dynamic nature of atoll islands, with significant shifts in shoreline position observed over the period of analysis. Results suggest shoreline accretion is the dominant mode of change on the islands studied, often associated with a net increase in vegetated island area. However, considerable inter- and intra-atoll variability exists with regards to shoreline stability. Findings are discussed with respect to island morphodynamics and potential hazard mitigation and planning responses within atoll settings.

  13. Magnetic island induced bootstrap current on island dynamics in tokamaks

    SciTech Connect

    Shaing, K.C.; Spong, D.A.

    2006-02-15

    When a magnetic island is embedded in toroidally symmetric tokamaks, the toroidal symmetry in |B| is broken [K. C. Shaing, Phys. Rev. Lett. 87, 245003 (2001)]. Here, B is the magnetic field. This broken symmetry induces an additional bootstrap current density in the vicinity of the island. It is illustrated that this island induced bootstrap current density modifies the island evolution equation and imposes a lower limit on the absolute value of the tearing mode stability parameter {delta}{sup '} for the island to be unstable. This lower limit depends on the local poloidal plasma beta {beta}{sub p}, the ratio of the plasma pressure to the poloidal magnetic field pressure. If {beta}{sub p} is high enough, the magnetic island is stable. This mechanism provides an alternative route to stabilize the island.

  14. Magnetic Island Induced Bootstrap Current on Island Dynamics in Tokamaks

    SciTech Connect

    Spong, Donald A; Shaing, K. C.

    2006-02-01

    When a magnetic island is embedded in toroidally symmetric tokamaks, the toroidal symmetry in |B| is broken [K. C. Shaing, Phys. Rev. Lett. 87, 245003 (2001)] . Here, B is the magnetic field. This broken symmetry induces an additional bootstrap current density in the vicinity of the island. It is illustrated that this island induced bootstrap current density modifies the island evolution equation and imposes a lower limit on the absolute value of the tearing mode stability parameter |{Delta}{prime}| for the island to be unstable. This lower limit depends on the local poloidal plasma beta {beta}{sub p}, the ratio of the plasma pressure to the poloidal magnetic field pressure. If {beta}{sub p} is high enough, the magnetic island is stable. This mechanism provides an alternative route to stabilize the island.

  15. Maternal Antibody Transmission in Relation to Mother Fluctuating Asymmetry in a Long-Lived Colonial Seabird: The Yellow-Legged Gull Larus michahellis

    PubMed Central

    Hammouda, Abdessalem; Selmi, Slaheddine; Pearce-Duvet, Jessica; Chokri, Mohamed Ali; Arnal, Audrey; Gauthier-Clerc, Michel; Boulinier, Thierry

    2012-01-01

    Female birds transfer antibodies to their offspring via the egg yolk, thus possibly providing passive immunity against infectious diseases to which hatchlings may be exposed, thereby affecting their fitness. It is nonetheless unclear whether the amount of maternal antibodies transmitted into egg yolks varies with female quality and egg laying order. In this paper, we investigated the transfer of maternal antibodies against type A influenza viruses (anti-AIV antibodies) by a long-lived colonial seabird, the yellow-legged gull (Larus michahellis), in relation to fluctuating asymmetry in females, i.e. the random deviation from perfect symmetry in bilaterally symmetric morphological and anatomical traits. In particular, we tested whether females with greater asymmetry transmitted fewer antibodies to their eggs, and whether within-clutch variation in yolk antibodies varied according to the maternal level of fluctuating asymmetry. We found that asymmetric females were in worse physical condition, produced fewer antibodies, and transmitted lower amounts of antibodies to their eggs. We also found that, within a given clutch, yolk antibody level decreased with egg laying order, but this laying order effect was more pronounced in clutches laid by the more asymmetric females. Overall, our results support the hypothesis that maternal quality interacts with egg laying order in determining the amount of maternal antibodies transmitted to the yolks. They also highlight the usefulness of fluctuating asymmetry as a sensitive indicator of female quality and immunocompetence in birds. PMID:22590497

  16. Detection limits and cost comparisons of human- and gull-associated conventional and quantitative PCR assays in artificial and environmental waters.

    PubMed

    Riedel, Timothy E; Zimmer-Faust, Amity G; Thulsiraj, Vanessa; Madi, Tania; Hanley, Kaitlyn T; Ebentier, Darcy L; Byappanahalli, Muruleedhara; Layton, Blythe; Raith, Meredith; Boehm, Alexandria B; Griffith, John F; Holden, Patricia A; Shanks, Orin C; Weisberg, Stephen B; Jay, Jennifer A

    2014-04-01

    Some molecular methods for tracking fecal pollution in environmental waters have both PCR and quantitative PCR (qPCR) assays available for use. To assist managers in deciding whether to implement newer qPCR techniques in routine monitoring programs, we compared detection limits (LODs) and costs of PCR and qPCR assays with identical targets that are relevant to beach water quality assessment. For human-associated assays targeting Bacteroidales HF183 genetic marker, qPCR LODs were 70 times lower and there was no effect of target matrix (artificial freshwater, environmental creek water, and environmental marine water) on PCR or qPCR LODs. The PCR startup and annual costs were the lowest, while the per reaction cost was 62% lower than the Taqman based qPCR and 180% higher than the SYBR based qPCR. For gull-associated assays, there was no significant difference between PCR and qPCR LODs, target matrix did not effect PCR or qPCR LODs, and PCR startup, annual, and per reaction costs were lower. Upgrading to qPCR involves greater startup and annual costs, but this increase may be justified in the case of the human-associated assays with lower detection limits and reduced cost per sample. PMID:24583609

  17. Detection limits and cost comparisons of human- and gull-associated conventional and quantitative PCR assays in artificial and environmental waters

    USGS Publications Warehouse

    Riedel, Timothy E.; Zimmer-Faust, Amity G.; Thulsiraj, Vanessa; Madi, Tania; Hanley, Kaitlyn T.; Ebentier, Darcy L.; Byappanahalli, Muruleedhara N.; Layton, Blythe; Raith, Meredith; Boehm, Alexandria B.; Griffith, John F.; Holden, Patricia A.; Shanks, Orin C.; Weisberg, Stephen B.; Jay, Jennifer A.

    2014-01-01

    Some molecular methods for tracking fecal pollution in environmental waters have both PCR and quantitative PCR (qPCR) assays available for use. To assist managers in deciding whether to implement newer qPCR techniques in routine monitoring programs, we compared detection limits (LODs) and costs of PCR and qPCR assays with identical targets that are relevant to beach water quality assessment. For human-associated assays targeting Bacteroidales HF183 genetic marker, qPCR LODs were 70 times lower and there was no effect of target matrix (artificial freshwater, environmental creek water, and environmental marine water) on PCR or qPCR LODs. The PCR startup and annual costs were the lowest, while the per reaction cost was 62% lower than the Taqman based qPCR and 180% higher than the SYBR based qPCR. For gull-associated assays, there was no significant difference between PCR and qPCR LODs, target matrix did not effect PCR or qPCR LODs, and PCR startup, annual, and per reaction costs were lower. Upgrading to qPCR involves greater startup and annual costs, but this increase may be justified in the case of the human-associated assays with lower detection limits and reduced cost per sample.

  18. Contributions to the non-linear integrated Sachs-Wolfe effect: Birkinshaw-Gull effect and gravitational self-energy density

    NASA Astrophysics Data System (ADS)

    Merkel, Philipp M.; Schäfer, Björn Malte

    2013-05-01

    In this paper, we recompute contributions to the spectrum of the non-linear integrated Sachs-Wolfe (iSW)/Rees-Sciama effect in a dark energy cosmology. Focusing on the moderate non-linear regime, all dynamical fields involved are derived from the density contrast in Eulerian perturbation theory. Shape and amplitude of the resulting angular power spectrum are similar to that derived in previous work. With our purely analytical approach we identify two distinct contributions to the signal of the non-linear iSW effect: the change of the gravitational self-energy density of the large-scale structure with (conformal) time and gravitational lenses moving with the large-scale matter stream. In the latter we recover the Birkinshaw-Gull effect. As the non-linear iSW effect itself is inherently hard to detect, observational discrimination between its individual contributions is almost excluded. Our analysis, however, yields valuable insights into the theory of the non-linear iSW effect as a post-Newtonian relativistic effect on propagating photons.

  19. Effect of rapid modulation of circulating plasma testosterone concentration on begging, aggressive behavior and competition for food in black-headed gull (Larus ridibundus) chicks.

    PubMed

    Boncoraglio, Giuseppe; Groothuis, Ton G G

    2013-08-01

    Sibling competition mediated by begging behavior is extremely common in avian species and recent studies have highlighted the role of endogenous testosterone in regulating such phenomenon. However, current literature depicts an inconsistent pattern in altricial vs. semi-precocial species, with stimulating versus inhibitory effects of the hormone respectively. This is possibly due to a difference in the methodology of hormone treatment (short-term moderate dose versus a long-term stronger elevation, respectively) between the studies performed so far. In this study, we induced short-term moderate peaks in plasma testosterone levels, as applied in altricial bird species, and assessed the effects of our manipulation on begging, competitive and aggressive behavior in black-headed gull (Larus ridibundus) chicks, a semi-precocial species. Our results suggest that, unlike in altricial songbirds, temporary increase of plasma testosterone concentration suppresses begging and enhances aggressiveness towards intruders. However, it also increases aggression and the chances of getting priority while scrambling with nest mates to gain access to food. Thus, the inconsistencies in the hormonal control of begging behavior observed between altricial vs. semi-precocial birds seem real and perhaps related to species differences in complexity of the display and the nature of competition. These may be elucidated by future comparative studies. PMID:23962563

  20. Miscellaneous pocosin peat deposits of North Carolina: Gull Rock; Van Swamp; Bay City - Gum Swamp. Open-grounds pocos in Hofmann Forest; Angola Swamp; Holly Shelter; Green Swamp

    SciTech Connect

    Ingram, R.L.; Otte, L.J.; Witner, T.W.

    1983-06-01

    In earlier reports the coastal swamp or pocosin peat deposits of Dismal Swamp, Pamlimarle Peninsula, Croatan Forest, and Light Ground Pocosin were described (Ingram and Otte, 1980, 1981a, 1981b, and 1982). This report describes the remaining coastal swamp or pocosin deposits of the North Carolina Coastal Plain. Total peat resources of these remaining deposits are: (1) Gull Rock - 8100 acres, 4.6 million tons, moisture free, (2) Van Swamp - 6600 acres, 5.8 million tons, (3) Bay City - Gum Swamp - 12,3000 acres, 5.9 million tons, (4) Open Grounds - 11,000 acres, 6.3 million tons, (5) Hofmann Forest - 5200 acres, 4.2 million tons, (6) Angola Swamp - 21,900 acres, 15.2 million tons, (7) Holly Shelter - 9200 acres, 6.7 million tons, and (8) Green Swamp - 16,400 acres, 10.3 million tons. A revised estimation of the total peat resources of North Carolina is 700,000 acres (1100 sq mi) of peatland with 500 million tons of peat. Of this total, 290,000 acres (460 sq mi) is underlain by peat greater than 4 ft thick with 330 million tons of peat.

  1. Maternally derived testosterone and 17beta-estradiol in the eggs of Arctic-breeding glaucous gulls in relation to persistent organic pollutants.

    PubMed

    Verboven, Nanette; Verreault, Jonathan; Letcher, Robert J; Gabrielsen, Geir W; Evans, Neil P

    2008-08-01

    It is largely unknown if and how persistent organic pollutants (POPs) affect the transfer of maternal hormones to eggs. This occurs despite an increasing number of studies relating environmental conditions experienced by female birds at the time of egg formation to maternal hormonal effects. Here we report the concentrations of maternal testosterone, 17beta-estradiol and major classes of POPs (organochlorines, brominated flame retardants and metabolically-derived products) in the yolk of unincubated, third-laid eggs of the glaucous gull (Larus hyperboreus), a top-predator in the Arctic marine environment. Controlled for seasonal and local variation, positive correlations were found between the concentrations of certain POPs and testosterone. Contaminant-related changes in the relative concentrations of testosterone and 17beta-estradiol were also observed. In addition, yolk steroid concentrations were associated with contaminant profiles describing the proportions of different POPs present in the yolk. Eggs from nests in which two sibling eggs hatched or failed to hatch differed in POP profiles and in the relative concentrations of testosterone and 17beta-estradiol. Although the results of this correlative study need to be interpreted with caution, they suggest that contaminant-related changes in yolk steroids may occur, possibly affecting offspring performance over and above toxic effects brought about by POPs in eggs. PMID:18550446

  2. 75 FR 51098 - Protection Island and San Juan Islands National Wildlife Refuges, Jefferson, Island, San Juan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... Register on August 14, 2007 (72 FR 45444), announcing our intent to complete a CCP/EA and inviting public... Fish and Wildlife Service Protection Island and San Juan Islands National Wildlife Refuges, Jefferson, Island, San Juan, Skagit, and Whatcom Counties, WA AGENCY: Fish and Wildlife Service, Interior....

  3. LOUISIANA BARRIER ISLAND EROSION STUDY.

    USGS Publications Warehouse

    Sallenger,, Asbury H., Jr.; Penland, Shea; Williams, S. Jeffress; Suter, John R.

    1987-01-01

    During 1986, the U. S. Geological Survey and the Louisiana Geological Survey began a five-year cooperative study focused on the processes which cause erosion of barrier islands. These processes must be understood in order to predict future erosion and to better manage our coastal resources. The study area includes the Louisiana barrier islands which serve to protect 41% of the nation's wetlands. These islands are eroding faster than any other barrier islands in the United States, in places greater than 20 m/yr. The study is divided into three parts: geological development of barrier islands, quantitative processes of barrier island erosion and applications of results. The study focuses on barrier islands in Louisiana although many of the results are applicable nationwide.

  4. FLANDERS FIELDS MEMORIAL IN TRAFFIC ISLAND ON EAST DRIVE. VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FLANDERS FIELDS MEMORIAL IN TRAFFIC ISLAND ON EAST DRIVE. VIEW TO NORTHEAST. - Rock Island National Cemetery, Rock Island Arsenal, 0.25 mile north of southern tip of Rock Island, Rock Island, Rock Island County, IL

  5. Landscapes of Santa Rosa Island, Channel Islands National Park, California

    USGS Publications Warehouse

    Schumann, R. Randall; Minor, Scott A.; Muhs, Daniel R.; Pigati, Jeffery S.

    2014-01-01

    Santa Rosa Island (SRI) is the second-largest of the California Channel Islands. It is one of 4 east–west aligned islands forming the northern Channel Islands chain, and one of the 5 islands in Channel Islands National Park. The landforms, and collections of landforms called landscapes, of Santa Rosa Island have been created by tectonic uplift and faulting, rising and falling sea level, landslides, erosion and deposition, floods, and droughts. Landscape features, and areas delineating groups of related features on Santa Rosa Island, are mapped, classified, and described in this paper. Notable landscapes on the island include beaches, coastal plains formed on marine terraces, sand dunes, and sand sheets. In this study, the inland physiography has been classified into 4 areas based on relief and degree of fluvial dissection. Most of the larger streams on the island occupy broad valleys that have been filled with alluvium and later incised to form steep- to vertical-walled arroyos, or barrancas, leaving a relict floodplain above the present channel. A better understanding of the processes and mechanisms that created these landscapes enhances visitors’ enjoyment of their surroundings and contributes to improving land and resource management strategies in order to optimize and balance the multiple goals of conservation, preservation, restoration, and visitor experience.

  6. Charge Islands Through Tunneling

    NASA Technical Reports Server (NTRS)

    Robinson, Daryl C.

    2002-01-01

    It has been recently reported that the electrical charge in a semiconductive carbon nanotube is not evenly distributed, but rather it is divided into charge "islands." This paper links the aforementioned phenomenon to tunneling and provides further insight into the higher rate of tunneling processes, which makes tunneling devices attractive. This paper also provides a basis for calculating the charge profile over the length of the tube so that nanoscale devices' conductive properties may be fully exploited.

  7. 32 CFR 935.62 - Island Attorney.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Island Attorney. 935.62 Section 935.62 National... WAKE ISLAND CODE Judiciary § 935.62 Island Attorney. There is an Island Attorney, appointed by the General Counsel as needed. The Island Attorney shall serve at the pleasure of the General Counsel....

  8. 32 CFR 935.62 - Island Attorney.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Island Attorney. 935.62 Section 935.62 National... WAKE ISLAND CODE Judiciary § 935.62 Island Attorney. There is an Island Attorney, appointed by the General Counsel as needed. The Island Attorney shall serve at the pleasure of the General Counsel....

  9. 32 CFR 935.62 - Island Attorney.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Island Attorney. 935.62 Section 935.62 National... WAKE ISLAND CODE Judiciary § 935.62 Island Attorney. There is an Island Attorney, appointed by the General Counsel as needed. The Island Attorney shall serve at the pleasure of the General Counsel....

  10. 32 CFR 935.62 - Island Attorney.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Island Attorney. 935.62 Section 935.62 National... WAKE ISLAND CODE Judiciary § 935.62 Island Attorney. There is an Island Attorney, appointed by the General Counsel as needed. The Island Attorney shall serve at the pleasure of the General Counsel....

  11. 32 CFR 935.62 - Island Attorney.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Island Attorney. 935.62 Section 935.62 National... WAKE ISLAND CODE Judiciary § 935.62 Island Attorney. There is an Island Attorney, appointed by the General Counsel as needed. The Island Attorney shall serve at the pleasure of the General Counsel....

  12. Asthma and Native Hawaiians/Pacific Islanders

    MedlinePlus

    ... Other Pacific Islander > Asthma Asthma and Native Hawaiians/Pacific Islanders Native Hawaiians/Pacific Islanders are 70 percent more likely to have ... being told they had asthma, 2014 Native Hawaiian/Pacific Islander Non-Hispanic White Native Hawaiian/Pacific Islander/ ...

  13. Age of First Breeding Interacts with Pre- and Post-Recruitment Experience in Shaping Breeding Phenology in a Long-Lived Gull

    PubMed Central

    Bosman, Davy S.; Vercruijsse, Harry J. P.; Stienen, Eric W. M.; Vincx, Magda; Lens, Luc

    2013-01-01

    Individual variation in timing of breeding is a key factor affecting adaptation to environmental change, yet our basic understanding of the causes of such individual variation is incomplete. This study tests several hypotheses for age-related variation in the breeding timing of Lesser Black-backed Gulls, based on a 13 year longitudinal data set that allows to decouple effects of age, previous prospecting behavior, and years of breeding experience on arrival timing at the colony. At the population level, age of first breeding was significantly associated with timing of arrival and survival, i.e. individuals tended to arrive later if they postponed their recruitment, and individuals recruiting at the age of 4 years survived best. However, up to 81% of the temporal variation in arrival dates was explained by within-individual effects. When excluding the pre-recruitment period, the effect of increasing age on advanced arrival was estimated at 11 days, with prior breeding experience accounting for a 7 days advance and postponed breeding for a 4 days delay. Overall, results of this study show that delayed age of first breeding can serve to advance arrival date (days after December 1st) in successive breeding seasons throughout an individual’s lifetime, in large part due to the benefits of learning or experience gained during prospecting. However, prospecting and the associated delay in breeding also bear a survival cost, possibly because prospectors have been forced to delay through competition with breeders. More generally, results of this study set the stage for exploring integrated temporal shifts in phenology, resource allocation and reproductive strategies during individual lifecycles of long-lived migratory species. PMID:24324750

  14. Adaptation and diversification on islands.

    PubMed

    Losos, Jonathan B; Ricklefs, Robert E

    2009-02-12

    Charles Darwin's travels on HMS Beagle taught him that islands are an important source of evidence for evolution. Because many islands are young and have relatively few species, evolutionary adaptation and species proliferation are obvious and easy to study. In addition, the geographical isolation of many islands has allowed evolution to take its own course, free of influence from other areas, resulting in unusual faunas and floras, often unlike those found anywhere else. For these reasons, island research provides valuable insights into speciation and adaptive radiation, and into the relative importance of contingency and determinism in evolutionary diversification. PMID:19212401

  15. Island biogeography of the Anthropocene.

    PubMed

    Helmus, Matthew R; Mahler, D Luke; Losos, Jonathan B

    2014-09-25

    For centuries, biogeographers have examined the factors that produce patterns of biodiversity across regions. The study of islands has proved particularly fruitful and has led to the theory that geographic area and isolation influence species colonization, extinction and speciation such that larger islands have more species and isolated islands have fewer species (that is, positive species-area and negative species-isolation relationships). However, experimental tests of this theory have been limited, owing to the difficulty in experimental manipulation of islands at the scales at which speciation and long-distance colonization are relevant. Here we have used the human-aided transport of exotic anole lizards among Caribbean islands as such a test at an appropriate scale. In accord with theory, as anole colonizations have increased, islands impoverished in native species have gained the most exotic species, the past influence of speciation on island biogeography has been obscured, and the species-area relationship has strengthened while the species-isolation relationship has weakened. Moreover, anole biogeography increasingly reflects anthropogenic rather than geographic processes. Unlike the island biogeography of the past that was determined by geographic area and isolation, in the Anthropocene--an epoch proposed for the present time interval--island biogeography is dominated by the economic isolation of human populations. PMID:25254475

  16. Cognitive Constraints and Island Effects

    PubMed Central

    Hofmeister, Philip; Sag, Ivan A.

    2012-01-01

    Competence-based theories of island effects play a central role in generative grammar, yet the graded nature of many syntactic islands has never been properly accounted for. Categorical syntactic accounts of island effects have persisted in spite of a wealth of data suggesting that island effects are not categorical in nature and that non-structural manipulations that leave island structures intact can radically alter judgments of island violations. We argue here, building on work by Deane, Kluender, and others, that processing factors have the potential to account for this otherwise unexplained variation in acceptability judgments. We report the results of self-paced reading experiments and controlled acceptability studies which explore the relationship between processing costs and judgments of acceptability. In each of the three self-paced reading studies, the data indicate that the processing cost of different types of island violations can be significantly reduced to a degree comparable to that of non-island filler-gap constructions by manipulating a single non-structural factor. Moreover, this reduction in processing cost is accompanied by significant improvements in acceptability. This evidence favors the hypothesis that island-violating constructions involve numerous processing pressures that aggregate to drive processing difficulty above a threshold so that a perception of unacceptability ensues. We examine the implications of these findings for the grammar of filler-gap dependencies.* PMID:22661792

  17. Reunion Island Volcano Erupts

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On January 16, 2002, lava that had begun flowing on January 5 from the Piton de la Fournaise volcano on the French island of Reunion abruptly decreased, marking the end of the volcano's most recent eruption. These false color MODIS images of Reunion, located off the southeastern coast of Madagascar in the Indian Ocean, were captured on the last day of the eruption (top) and two days later (bottom). The volcano itself is located on the southeast side of the island and is dark brown compared to the surrounding green vegetation. Beneath clouds (light blue) and smoke, MODIS detected the hot lava pouring down the volcano's flanks into the Indian Ocean. The heat, detected by MODIS at 2.1 um, has been colored red in the January 16 image, and is absent from the lower image, taken two days later on January 18, suggesting the lava had cooled considerably even in that short time. Earthquake activity on the northeast flank continued even after the eruption had stopped, but by January 21 had dropped to a sufficiently low enough level that the 24-hour surveillance by the local observatory was suspended. Reunion is essentially all volcano, with the northwest portion of the island built on the remains of an extinct volcano, and the southeast half built on the basaltic shield of 8,630-foot Piton de la Fournaise. A basaltic shield volcano is one with a broad, gentle slope built by the eruption of fluid basalt lava. Basalt lava flows easily across the ground remaining hot and fluid for long distances, and so they often result in enormous, low-angle cones. The Piton de la Fournaise is one of Earth's most active volcanoes, erupting over 150 times in the last few hundred years, and it has been the subject of NASA research because of its likeness to the volcanoes of Mars. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  18. 19. New York Connecting Railroad: Randalls Island Viaduct. Randalls Island, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. New York Connecting Railroad: Randalls Island Viaduct. Randalls Island, New York Co., NY. Sec. 4207, MP 8.54. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  19. 15. New York Connecting Railroad: Wards Island Viaduct. Wards Island, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. New York Connecting Railroad: Wards Island Viaduct. Wards Island, New York Co., NY. Sec. 4207, MP 7.65. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  20. Islands and Non-islands in Native and Heritage Korean

    PubMed Central

    Kim, Boyoung; Goodall, Grant

    2016-01-01

    To a large extent, island phenomena are cross-linguistically invariable, but English and Korean present some striking differences in this domain. English has wh-movement and Korean does not, and while both languages show sensitivity to wh-islands, only English has island effects for adjunct clauses. Given this complex set of differences, one might expect Korean/English bilinguals, and especially heritage Korean speakers (i.e., early bilinguals whose L2 became their dominant language during childhood) to be different from native speakers, since heritage speakers have had more limited exposure to Korean, may have had incomplete acquisition and/or attrition, and may show significant transfer effects from the L2. Here we examine islands in heritage speakers of Korean in the U.S. Through a series of four formal acceptability experiments comparing these heritage speakers with native speakers residing in Korea, we show that the two groups are remarkably similar. Both show clear evidence for wh-islands and an equally clear lack of adjunct island effects. Given the very different linguistic environment that the heritage speakers have had since early childhood, this result lends support to the idea that island phenomena are largely immune to environmental influences and stem from deeper properties of the processor and/or grammar. Similarly, it casts some doubt on recent proposals that islands are learned from the input. PMID:26913017

  1. IslandViewer update: Improved genomic island discovery and visualization.

    PubMed

    Dhillon, Bhavjinder K; Chiu, Terry A; Laird, Matthew R; Langille, Morgan G I; Brinkman, Fiona S L

    2013-07-01

    IslandViewer (http://pathogenomics.sfu.ca/islandviewer) is a web-accessible application for the computational prediction and analysis of genomic islands (GIs) in bacterial and archaeal genomes. GIs are clusters of genes of probable horizontal origin and are of high interest because they disproportionately encode virulence factors and other adaptations of medical, environmental and industrial interest. Many computational tools exist for the prediction of GIs, but three of the most accurate methods are available in integrated form via IslandViewer: IslandPath-DIMOB, SIGI-HMM and IslandPick. IslandViewer GI predictions are precomputed for all complete microbial genomes from National Center for Biotechnology Information, with an option to upload other genomes and/or perform customized analyses using different settings. Here, we report recent changes to the IslandViewer framework that have vastly improved its efficiency in handling an increasing number of users, plus better facilitate custom genome analyses. Users may also now overlay additional annotations such as virulence factors, antibiotic resistance genes and pathogen-associated genes on top of current GI predictions. Comparisons of GIs between user-selected genomes are now facilitated through a highly requested side-by-side viewer. IslandViewer improvements aim to provide a more flexible interface, coupled with additional highly relevant annotation information, to aid analysis of GIs in diverse microbial species. PMID:23677610

  2. Islands and Non-islands in Native and Heritage Korean.

    PubMed

    Kim, Boyoung; Goodall, Grant

    2016-01-01

    To a large extent, island phenomena are cross-linguistically invariable, but English and Korean present some striking differences in this domain. English has wh-movement and Korean does not, and while both languages show sensitivity to wh-islands, only English has island effects for adjunct clauses. Given this complex set of differences, one might expect Korean/English bilinguals, and especially heritage Korean speakers (i.e., early bilinguals whose L2 became their dominant language during childhood) to be different from native speakers, since heritage speakers have had more limited exposure to Korean, may have had incomplete acquisition and/or attrition, and may show significant transfer effects from the L2. Here we examine islands in heritage speakers of Korean in the U.S. Through a series of four formal acceptability experiments comparing these heritage speakers with native speakers residing in Korea, we show that the two groups are remarkably similar. Both show clear evidence for wh-islands and an equally clear lack of adjunct island effects. Given the very different linguistic environment that the heritage speakers have had since early childhood, this result lends support to the idea that island phenomena are largely immune to environmental influences and stem from deeper properties of the processor and/or grammar. Similarly, it casts some doubt on recent proposals that islands are learned from the input. PMID:26913017

  3. Urban heat island

    NASA Technical Reports Server (NTRS)

    Kim, Hongsuk H.

    1991-01-01

    The phenomenon of urban heat island was investigated by the use of LANDSAT Thematic Mapper data sets collected over the metropolitan area of Washington DC (U.S.). By combining the retrieved spectral albedos and temperatures, urban modification on radiation budgets of five surface categories were analyzed. The surface radiation budget imagery of the area show that urban heating is attributable to a large heat flux from the rapidly heating surfaces of asphalt, bare soil and short grass. In summer, symptoms of diurnal heating begin to appear by mid morning and can be about 10 degrees warmer than nearby woodlands in summer.

  4. Pine Island Glacier, Antarctica

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This pair of MISR images of the Pine Island Glacier in western Antarctica was acquired on December 12, 2000 during Terra orbit 5246. At left is a conventional, true-color image from the downward-looking (nadir) camera. The false-color image at right is a composite of red band data taken by the MISR forward 60-degree, nadir, and aftward 60-degree cameras, displayed in red, green, and blue colors, respectively. Color variations in the left (true-color) image highlight spectral differences. In the multi-angle composite, on the other hand, color variations act as a proxy for differences in the angular reflectance properties of the scene. In this representation, clouds show up as light purple. Blue to orange gradations on the surface indicate a transition in ice texture from smooth to rough. For example, the bright orange 'carrot-like' features are rough crevasses on the glacier's tongue. In the conventional nadir view, the blue ice labeled 'rough crevasses' and 'smooth blue ice' exhibit similar coloration, but the multi-angle composite reveals their different textures, with the smoother ice appearing dark purple instead of orange. This could be an indicator of different mechanisms by which this ice is exposed. The multi-angle view also reveals subtle roughness variations on the frozen sea ice between the glacier and the open water in Pine Island Bay.

    To the left of the 'icebergs' label are chunks of floating ice. Additionally, smaller icebergs embedded in the frozen sea ice are visible below and to the right of the label. These small icebergs are associated with dark streaks. Analysis of the illumination geometry suggests that these streaks are surface features, not shadows. Wind-driven motion and thinning of the sea ice in the vicinity of the icebergs is one possible explanation.

    Recently, Robert Bindschadler, a glaciologist at the NASA Goddard Space Flight Center discovered in Landsat 7 imagery a newly-formed crack traversing the Pine Island Glacier. This crack

  5. Fire Island National Seashore

    USGS Publications Warehouse

    Brock, John C.; Wright, C. Wayne; Patterson, Matt; Nayagandhi, Amar; Patterson, Judd

    2007-01-01

    These lidar-derived topographic maps were produced as a collaborative effort between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program, the National Park Service (NPS), Northeast Coastal and Barrier Network, Inventory and Monitoring Program, and the National Aeronautics and Space Administration (NASA) Wallops Flight Facility. The aims of the partnership that created this product are to develop advanced survey techniques for mapping barrier island geomorphology and habitats, and to enable the monitoring of ecological and geological change within National Seashores. This product is based on data from an innovative airborne lidar instrument under development at the NASA Wallops Flight Facility, the NASA Experimental Advanced Airborne Research Lidar (EAARL).

  6. Profile: Native Hawaiians and Pacific Islanders

    MedlinePlus

    ... Hawaiian/Other Pacific Islander Profile: Native Hawaiians and Pacific Islanders (Map of the US with the states that have significant Native Hawaiian/Pacific Islander populations according to the Census Bureau) HI - ...

  7. Infant Mortality and Asians and Pacific Islanders

    MedlinePlus

    ... Infant Heath & Mortality Infant Mortality and Asians and Pacific Islanders Among Asian/Pacific Islanders, Sudden Infant Death Syndrome (SIDS) is the fourth leading cause of infant mortality. Asian/Pacific Islanders women generally have lower infant mortality rates ...

  8. Heart Disease and Asians and Pacific Islanders

    MedlinePlus

    ... American > Heart Disease Heart Disease and Asians and Pacific Islanders Overall, Asian American adults are less likely ... Disease Death Rates per 100,000 (2013) Asians/Pacific Islanders Non-Hispanic White Asians/Pacific Islanders /Non- ...

  9. Immunizations and Asians and Pacific Islanders

    MedlinePlus

    ... Profiles > Asian American > Immunizations Immunizations and Asians and Pacific Islanders Asian/Pacific Islander adults are 10% less likely to ever ... to non-Hispanic white adults. In 2014, Asian/Pacific Islander adults aged 65 years and older were ...

  10. Diabetes and Native Hawaiians/Pacific Islanders

    MedlinePlus

    ... Other Pacific Islander > Diabetes Diabetes and Native Hawaiians/Pacific Islanders Asian Americans, in general, have the same ... However, there are differences within the Native Hawaiian/Pacific Islander population. From a national survey, Native Hawaiians/ ...

  11. Ecosystem respiration, vegetation development and soil nitrogen in relation to breeding density of seagulls on a pristine volcanic island, Surtsey, Iceland

    NASA Astrophysics Data System (ADS)

    Sigurdsson, B. D.; Magnusson, B.

    2009-08-01

    Since its birth in 1963 by volcanic eruption in the North Atlantic Ocean off Iceland, Surtsey has been a unique natural laboratory on how organisms colonize volcanic islands and form ecosystems with contrasting structure and function. In July, 2004, ecosystem respiration rate, soil properties and surface cover of vascular plants were measured on 21 plots distributed among the main plant communities found 40 years after the primary succession started. The plots could be divided into two groups, inside and outside seagull (Larus sp.) colonies found on the island. Vegetation cover of the plots was strongly related to the density of seagull nests within and around them. The occurrence of seagull nests and increased vegetation also coincided with significant increase in ecosystem respiration, soil carbon and nitrogen, and with significantly lower soil pH and soil temperatures. The ecosystem respiration was high inside the gull colonies, similar to the highest fluxes measured in drained wetlands or agricultural fields in Iceland. The most important factor for vegetation succession and ecosystem function on Surtsey seems to be the amount of nitrogen, which was mainly brought in by the seagulls.

  12. Opportunity at 'Cook Islands'

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,825th Martian day, or sol, of Opportunity's surface mission (March 12, 2009). North is at the top.

    The rover had driven half a meter (1.5 feet) earlier on Sol 1825 to fine-tune its location for placing its robotic arm onto an exposed patch of outcrop including a target area informally called 'Cook Islands.' On the preceding sol, Opportunity turned around to drive frontwards and then drove 4.5 meters (15 feet) toward this outcrop. The tracks from the SOl 1824 drive are visible near the center of this view at about the 11 o'clock position. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). Opportunity had previously been driving backward as a strategy to redistribute lubrication in a wheel drawing more electrical current than usual.

    The outcrop exposure that includes 'Cook Islands' is visible just below the center of the image.

    The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

    This view is presented as a cylindrical projection with geometric seam correction.

  13. Fluid Management Plan for the Project Shoal Area, Off-sites Subproject, CAU 447, Revision 0 (with Record of Technical Change No. 1, 2, and 3)

    SciTech Connect

    USDOE /NV

    1999-04-01

    The U.S. Department of Energy, Nevada Operations Office (DOE/NV) has initiated the Off-Site Project to characterize the hazards posed to human health and the environment as a result of underground nuclear testing activities at facilities other than the Nevada Test Site (NTS). The Project Shoal Area (PSA) is one of the Off-Sites Project areas located off the NTS, but within the state of Nevada. The PSA is located approximately 48 kilometers (30 miles) southeast of Fallon, Nevada. Four wells were drilled at the PSA in 1996 as part of the site investigation administered through the Federal Facility Agreement and Consent Order (FFACO) (1996). The hydrogeologic data gathered from these wells was used to support the groundwater flow and contaminant transport modeling of the PSA. However, the subsequent evaluation of the groundwater model concluded that further delineation of the subsurface was required to reduce uncertainties in the model. In accordance with the FFACO, an addendum to the Corrective Action Investigation Plan (CAIP) for the proposed PSA subsurface investigation, Corrective Action Unit 447, was developed. The addendum proposed the drilling and construction of four additional wells and the conduct of hydrologic testing at the PSA. This Fluid Management Plan (FMP) provides guidance for the management of fluids generated from the well construction and testing activities at the PSA.

  14. An Island Effect in Japanese.

    ERIC Educational Resources Information Center

    Richards, Norvin

    2000-01-01

    Develops an argument for a pied-piping approach to the apparent absence of island effects in Japanese, along the lines of Nishigauchi (1986, 1990). Investigates the nature of pied-piping, developing a theory that accounts for the fact that wh-islands cannot be pied-piped. (Author/VWL)

  15. Geologic control on the evolution of the inner shelf morphology offshore of the Mississippi barrier islands, northern Gulf of Mexico, USA

    USGS Publications Warehouse

    Flocks, James G.; Kindinger, Jack G.; Kelso, Kyle W.

    2015-01-01

    Between 2008 and 2013, high-resolution geophysical surveys were conducted around the Mississippi barrier islands and offshore. The sonar surveys included swath and single-beam bathymetry, sidescan, and chirp subbottom data collection. The geophysical data were groundtruthed using vibracore sediment collection. The results provide insight into the evolution of the inner shelf and the relationship between the near surface geologic framework and the morphology of the coastal zone. This study focuses on the buried Pleistocene fluvial deposits and late Holocene shore-oblique sand ridges offshore of Petit Bois Island and Petit Bois Pass. Prior to this study, the physical characteristics, evolution, and interrelationship of the ridges between both the shelf geology and the adjacent barrier island platform had not been evaluated. Numerous studies elsewhere along the coastal margin attribute shoal origin and sand-ridge evolution to hydrodynamic processes in shallow water (<20 m). Here we characterize the correlation between the geologic framework and surface morphology and demonstrate that the underlying stratigraphy must also be considered when developing an evolutionary conceptual model. It is important to understand this near surface, nearshore dynamic in order to understand how the stratigraphy influences the long-term response of the coastal zone to sea-level rise. The study also contributes to a growing body of work characterizing shore-oblique sand ridges which, along with the related geology, are recognized as increasingly important components to a nearshore framework whose origins and evolution must be understood and inventoried to effectively manage the coastal zone.

  16. Geologic control on the evolution of the inner shelf morphology offshore of the Mississippi barrier islands, northern Gulf of Mexico, USA

    NASA Astrophysics Data System (ADS)

    Flocks, James G.; Kindinger, Jack L.; Kelso, Kyle W.

    2015-06-01

    Between 2008 and 2013, high-resolution geophysical surveys were conducted around the Mississippi barrier islands and offshore. The sonar surveys included swath and single-beam bathymetry, sidescan, and chirp subbottom data collection. The geophysical data were groundtruthed using vibracore sediment collection. The results provide insight into the evolution of the inner shelf and the relationship between the near surface geologic framework and the morphology of the coastal zone. This study focuses on the buried Pleistocene fluvial deposits and late Holocene shore-oblique sand ridges offshore of Petit Bois Island and Petit Bois Pass. Prior to this study, the physical characteristics, evolution, and interrelationship of the ridges between both the shelf geology and the adjacent barrier island platform had not been evaluated. Numerous studies elsewhere along the coastal margin attribute shoal origin and sand-ridge evolution to hydrodynamic processes in shallow water (<20 m). Here we characterize the correlation between the geologic framework and surface morphology and demonstrate that the underlying stratigraphy must also be considered when developing an evolutionary conceptual model. It is important to understand this near surface, nearshore dynamic in order to understand how the stratigraphy influences the long-term response of the coastal zone to sea-level rise. The study also contributes to a growing body of work characterizing shore-oblique sand ridges which, along with the related geology, are recognized as increasingly important components to a nearshore framework whose origins and evolution must be understood and inventoried to effectively manage the coastal zone.

  17. Applying Tafkaa For Atmospheric Correction of Aviris Over Coral Ecosystems In The Hawaiian Islands

    NASA Technical Reports Server (NTRS)

    Goodman, James A.; Montes, Marcos J.; Ustin, Susan L.

    2004-01-01

    Growing concern over the health of coastal ecosystems, particularly coral reefs, has produced increased interest in remote sensing as a tool for the management and monitoring of these valuable natural resources. Hyperspectral capabilities show promising results in this regard, but as yet remain somewhat hindered by the technical and physical issues concerning the intervening water layer. One such issue is the ability to atmospherically correct images over shallow aquatic areas, where complications arise due to varying effects from specular reflection, wind blown surface waves, and reflectance from the benthic substrate. Tafkaa, an atmospheric correction algorithm under development at the U.S. Naval Research Laboratory, addresses these variables and provides a viable approach to the atmospheric correction issue. Using imagery from the Advanced Visible InfraRed Imaging Spectrometer (AVIRIS) over two shallow coral ecosystems in the Hawai ian Islands, French Frigate Shoals and Kane ohe Bay, we first demonstrate how land-based atmospheric corrections can be limited in such an environment. We then discuss the input requirements and underlying algorithm concepts of Tafkaa and conclude with examples illustrating the improved performance of Tafkaa using the same AVIRIS images.

  18. 2. Light tower, view west towards Squirrel Island, south and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Light tower, view west towards Squirrel Island, south and east sides - Ram Island Light Station, Ram Island, south of Ocean Point & just north of Fisherman Island, marking south side of Fisherman Island Passage, Ocean Point, Lincoln County, ME

  19. Plant communities of Santa Rosa Island, Channel Islands National Park

    USGS Publications Warehouse

    Clark, Ronilee A.; Halvorson, William L.; Sawdo, Andell A.; Danielsen, Karen C.

    1990-01-01

    A survey of the plant communities on Santa Rosa Island, Channel Islands National Park, was conducted from January through July 1988.  Vegetation data were collected at 296 sites using a releve technique.  The plant communities described include: grassland, coastal marsh, caliche scrub, coastal sage scrub, lupine scrub, baccharis scrub, coastal bluff scrub, coastal dune scrub, mixed chaparral, mixed woodland, torrey pine woodland, closed-cone pine woodland, island oak woodland, riparian woodland, and riparian herbaceous vegetation. The areal extent of each community was mapper on USGS 7.5' topographic maps, and digitized for GIS manipulation.

  20. Anatahan Volcano, Mariana Islands

    NASA Technical Reports Server (NTRS)

    2008-01-01

    In the early hours of February 7, ASTER captured this nighttime thermal infrared image of an eruption of Anatahan Volcano in the central Mariana Islands. The summit of the volcano is bright indicating there is a very hot area there. Streaming to the west is an ash plume, visible by the red color indicating the presence of silicate-rich particles. Dark grey areas are clouds that appear colder than the ocean. Anatahan is a stratovolcano that started erupting in May 2003, forming a new crater.

    The image covers an area of 56.3 x 41.8 km, and is located 16 degrees north latitude and 145.6 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.