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Sample records for mangrove lagoon survival

  1. Enteric viruses in a mangrove lagoon, survival and shellfish incidence

    SciTech Connect

    Lopez de Cardona, I.; Bermudez, M.; Billmire, E.; Hazen, T.C.

    1988-12-31

    Mangrove oysters (Crassostrea rhizophorae) were screened for enteric viruses. For 18 months oysters were collected from Cano Boqueron, a tropical mangrove lagoon on the southwest coast of Puerto Rico. This popular tourist resort has two primary sewage treatment plants which service 158 single family cabanas. In spite of the heavy seasonal input of sewage to Cano Boqueron and high densities of fecal coliform bacteria, enteric viruses were not detected in shellfish meat. Because no viruses were detected in the oysters, a virus survival study was performed. Poliovirus type 1 was placed in diffusion chambers in situ at two sites in Cano Boqueron. More than 95% of the poliovirus inactivation occurred within 24 h. Virus inactivation was significantly different by site, indicating different inactivation rates within the lagoon. Chamber studies done simultaneously with Escherichia coli did not reveal differences between sites. It is suggested that the sewage effluent had an antiviral effect in the absence of an antibacterial effect. This study demonstrates the importance for establishing microbial contamination standards for shellfish growing waters in the tropics based upon in situ studies with tropical species, e.g. mangrove oyster.

  2. Methane Dynamics in Sediments from Mangrove-dominated Costal Lagoons

    NASA Astrophysics Data System (ADS)

    Chuang, P. C.; Paytan, A.; Young, M. B.

    2014-12-01

    Porewater methane and sulfate concentrations from cored sediments have been measured in two coastal mangrove ecosystems (Celestún and Chelem Lagoons) on the Yucatán Peninsula, Mexico. Methane exists in shallow sediments while sulfate is not depleted and stable carbon isotopes of methane (-87.27‰ ~ -62.08‰) imply high methane fluxes/production rates below and within the cored sediment depths. The preliminary results from a transport-reaction model show that methane emitted to the water column from these sediments could be 17.8 mg m-2 d-1 in Celestún Lagoon and much higher (565 mg m-2 d-1) in Chelem Lagoon. Since the water depths are shallow (mostly less than 100 cm), the high fluxes of methane could contribute to the atmosphere. The objectives of this study will aim to understand the biogeochemical cycles for methane and sulfate in sediments. A numerical transport-reaction model will be applied to the sedimentary geochemical data (methane, sulfate, chloride, particulate organic carbon (POC) and stable carbon isotopes of headspace methane) from the two lagoons to estimate sulfate reduction, methane oxidation and production rates and advective methane fluxes. The modeled results will be used to discuss the role of methane from mangrove areas and their potential contribution to the global methane cycle.

  3. [The mangrove and others vegetation associations in de Gandoca lagoon, Limón, Costa Rica].

    PubMed

    Coll, M; Fonseca, A C; Cortés, J

    2001-12-01

    Six plant associations were identified at Gandoca Lagoon by photointerpretation and field verification: a) mangroves, b) palm trees swamp, and palm trees with Acrostichum aureum and A. danaefolium, c) mixed palm trees, d) very humid tropical rain forest, and e) tropical beach vegetation. The mangroves cover 12.5 ha surrounding the lagoon and extend 2 km up the Gandoca River. Rhizophora mangle (red mangrove) was the dominant species, with Avicennia germinans (black mangrove), Laguncularia racemosa (white mangrove) and Conocarpus erectus (buttonwood) also present. Moving inland the mangroves grade into a tropical rain forest. Gandoca, the largest and best preserved mangrove of Caribbean Costa Rica, tripled its area from 1976 to 2000. Possible causes include sedimentation and the Limón earthquake, which may have subside the lagoon area.

  4. Benthic foraminifera of Puerto Rican mangrove-lagoon systems: Potential for paleoenvironmental interpretations

    SciTech Connect

    Culver, S.J. )

    1990-02-01

    Recent foraminiferal assemblages from four traverses across mangrove-lagoonal environments off Puerto Rico exhibit patterns of distribution that should be useful in paleoenvironmental interpretations. Variations in sediment substrate type, abundance and distribution of marine vegetation, and degree of exposure to wave and current activity appear to be important factors related to foraminiferal distributions and abundances. Cluster analysis of foraminiferal abundance data distinguishes four major assemblages. Other generally recognizable trends in foraminiferal assemblages include: offshore increase in species diversity; offshore increase in percent miliolids while percent rotaliids remain more or less constant; small peaks in percent textulariids immediately adjacent to mangrove growth; almost 100% agglutinated assemblages in fully mangrove environments; offshore increase in foraminiferal number except in areas of abundant Halimeda plate production where numbers of foraminifera are diluted; restriction of high abundances of Fissurina, Nonionella, Fursenkoina and Helenina to lagoons behind mangrove islands; restrictions of high abundances of Rosalina, Cibicides, Discorbis, Spiroloculina, Cyclogyra, Quinqueloculina, Amphistegina, Peneroplis and Archaias to lagoons seaward of mangrove islands. These trends provide a micropaleontological link between a potential petroleum source, mangrove swamps, and the potential petroleum reservoir, reef rocks.

  5. [Mangrove dynamics in the Cispata lagoon system (Colombian Caribbean) during last 900 years].

    PubMed

    Castaño, Ana; Urrego, Ligia; Bernal, Gladys

    2010-12-01

    The lagoon complex of Cispatá (old Sinú river delta) located at the Northwestern coast of the Colombian Caribbean, encloses one of the biggest mangrove areas in this region. This area has changed during the last 330 years because of several environmental and climatic causes, mainly changes in the position of the delta (Sinú River), which is the main freshwater source in this area, and sea level rise. We hypothesized that the climatic and geomorphologic dynamics has caused changes in the extension and composition of mangrove vegetation, especially during last 150 years. The dynamics of mangroves during the last 900 years was reconstructed based on the changes in the stratigraphy, pollen record, calcite concentrations (CaCO3) and C/N ratio, along two sediment cores from La Flotante and Navio lagoons, located in Cispatá complex. The age model was built based on lineal interpolation of 210Pb ages and changes in granulometry. Establishment and expansion of mangrove forests during the last 900 years were related to fluviomarine dynamics in the area and the lagoon formation. During the period encompassed between 1064 and 1762 A.D., the Mestizos spit was formed when marine conditions predominated in the surroundings of La Flotante Lagoon. At the site of Navío, a river dominated lagoon, terrigenous conditions dominated since 1830. Although the colonization of herbaceous pioneer vegetation started between 1142 and 1331 A.D., mangrove colonization only took place since 1717 A.D. Mangrove colonization was a result of the delta progradation. In 1849 A.D. the Sinú river delta migrated to the Cispatá bay. The eustatic sea level rise, the increase in river discharges and sedimentation rates produced the establishment of mangrove forests dominated by Rhizophora since 1849. Since 1900 a marine intrusion was recorded in both lagoons. In 1938, the migration of the delta toward its actual location in Tinajones gave place to the formation of the present lagoon system and to the

  6. Methane fluxes from tropical coastal lagoons surrounded by mangroves, Yucatán, Mexico

    NASA Astrophysics Data System (ADS)

    Chuang, P.-C.; Young, M. B.; Dale, A. W.; Miller, L. G.; Herrera-Silveira, J. A.; Paytan, A.

    2017-05-01

    Methane concentrations in the water column and emissions to the atmosphere were determined for three tropical coastal lagoons surrounded by mangrove forests on the Yucatán Peninsula, Mexico. Surface water dissolved methane was sampled at different seasons over a period of 2 years in areas representing a wide range of salinities and anthropogenic impacts. The highest surface water methane concentrations (up to 8378 nM) were measured in a polluted canal associated with Terminos Lagoon. In Chelem Lagoon, methane concentrations were typically lower, except in the polluted harbor area (1796 nM). In the relatively pristine Celestún Lagoon, surface water methane concentrations ranged from 41 to 2551 nM. Methane concentrations were negatively correlated with salinity in Celestún, while in Chelem and Terminos high methane concentrations were associated with areas of known pollution inputs, irrespective of salinity. The diffusive methane flux from surface lagoon water to the atmosphere ranged from 0.0023 to 15 mmol CH4 m-2 d-1. Flux chamber measurements revealed that direct methane release as ebullition was up to 3 orders of magnitude greater than measured diffusive flux. Coastal mangrove lagoons may therefore be an important natural source of methane to the atmosphere despite their relatively high salinity. Pollution inputs are likely to substantially enhance this flux. Additional statistically rigorous data collected globally are needed to better consider methane fluxes from mangrove-surrounded coastal areas in response to sea level changes and anthropogenic pollution in order to refine projections of future atmospheric methane budgets.

  7. Trematode infections in Pirenella conica in three sites of a mangrove lagoon in Sinai.

    PubMed

    Taraschewski, H; Paperna, I

    1982-01-01

    Over a period of 11 months, eight samples of Pirenella conica were taken at each of three sites of a mangrove lagoon in Sinai. Infection with larval trematodes, especially of Heterophyidae, was highest at the site within the mangrove thicket with a breeding colony of reef herons, the supposed definitive hosts of the Heterophyidae. The lowest frequency of infection was recorded from a tide-pool on the broad sand-flats surrounding the lagoon, where there was a great variation in the abundance of snails and xiphidiocercariae were more common than heterophyid cercariae. Predation from fish or other molluscs did not appear to be an important factor at either of these two sites. In all three sites, double infections of Heterophyidae and trematodes with xiphidiocercariae as well as of Heterophyidae and Echinostomatidae occurred less frequently than theoretically expected, but there was no competitive exclusion between Echinostomatidae and xiphidiocercariae.

  8. [Spatial and temporal mangrove litter production in Barra de Navidad lagoon, Jalisco, México].

    PubMed

    Mendoza-Morales, Alma J; González-Sansón, Gaspar; Aguilar-Betancourt, Consuelo

    2016-03-01

    Barra de Navidad lagoon is a coastal wetland of international importance (Ramsar site) and it is included among the 81 Mexican mangrove priority sites. One of the most valued characteristics of this lagoon is the presence of mangrove forest in a good conservation state. The goal of our research was the measurement of mangrove litter production and environmental factors influencing its dynamics. The mangrove area was divided into seven zones and litterfall was monthly sampled from November 2011 to October 2012 using 0.25 m(2) square collectors made with mosquito mesh (1 mm) and positioned at 1.3 m above the ground. Abiotic variables of the interstitial water were measured simultaneously at each zone in permanent plots using a multi-parameter probe, YSI-556-M. Total mean value of litterfall production, weighted by zone surface, was 19.12 ± 1.23 gPS/m(2).mo (2.29 t/ha.year). This low productivity is a consequence of the region’s dry climate and low tide range. The species Avicennia germinans and Laguncularia racemosa produced more than 80 % of total litterfall, while Rhizophora mangle contributed only 16 % and Conocarpus erectus < 4 %. A significant correlation between litterfall production and abiotic variables was found (e.g. salinity and interstitial water depth). We concluded that there are significant spatial variations in soil abiotic variables which are correlated with differences in mangrove species composition, and produce, together with the life cycles stages of those species, significant variations in the quantity and composition of litterfall. Future research will be focused on quantifying spatial variations in forest structure and their relationship with litterfall production.

  9. Quantifying Methane Fluxes in Sediments from Mangrove-dominated Costal Lagoons

    NASA Astrophysics Data System (ADS)

    Chuang, P.; Young, M. B.; Paytan, A.

    2012-12-01

    Many studies have focused on methane emission from wetland sediments to the water column and atmosphere. However, there is growing evidence that organic rich, highly productive coastal areas such as mangrove-dominated lagoons and estuaries may have high rates of atmospheric methane flux, particularly in polluted areas. Dissolved methane concentrations in surface water and sediments have been measured in two coastal mangrove ecosystems (Celestún and Chelem Lagoons) on the Yucatán Peninsula, Mexico and the estimated diffusive methane fluxes to the atmosphere in both lagoons can reach to 2600 and 80 kg CH4/yr respectively with a much larger yet not quantified ebullition flux . The objectives of this study are to understand the sources and sinks for methane in sediments, how much methane is released from the sediment to water column and the relative contribution of diffusive and bubble fluxes. In addition rates/percentages of methane oxidized in the sediment and water column that lower methane flux to the atmosphere are quantified. Sedimentary geochemical data (methane, sulfate, chloride, particulate organic carbon (POC) and stable carbon isotopes of headspace methane) from the two lagoons were also measured to determine the impact of different salinities and degrees of pollution on POC mineralization and methane fluxes. Stable carbon isotopes of methane data indicate gas productions mainly by CO2 reduction with minor acetate fermentation signatures. A numerical transport-reaction model will be apply to the data to estimate sulfate reduction, methane oxidation and production rates and advective methane fluxes. The modeled results will be compared to methane bubble fluxes measured by flux chambers to obtain total methane emissions from sediment and discuss the role of methane from mangriove areas in impacting global climate change.

  10. Litterfall production of mangroves in the Huizache-Caimanero lagoon system, México

    USGS Publications Warehouse

    Flores-Cárdenas, Francisco; Hurtado-Oliva, Miguel Ángel; Doyle, Thomas W.; Nieves-Sotol, Mario; Díaz-Castro, Sara; Manzano-Sarabia, Marlenne

    2017-01-01

    The ecological legacy of the Huizache-Caimanero lagoon system has long been known as a trophically rich and productive ecosystem that supported artisanal fisheries of local and regional importance; however, a decline in fisheries' yields has been observed in recent decades. Mangroves are a fundamental component of this ecosystem, though data records and field studies are lacking in describing their structure and seasonal characteristics. Mangrove litterfall production was monitored during 2012–13 and described for the dominant species, Avicennia germinans (L.) Stearn and Laguncularia racemosa (L.) C.F. Gaertn. Forest surveys and monthly litter collections were obtained along a latitudinal gradient within the larger lagoon system to characterize the forest structure, leaf biomass, and related biological indicators (chlorophyll a concentration and Normalized Difference Vegetation Index [NDVI] estimated on leaf tissues). Results showed that structural characteristics (diameter at breast height, basal area, height, and crown diameter) were greater in Huizache, corresponding to patches with a dominance of A. germinans, while higher stem density was recorded for L. racemosa in Caimanero, comparatively similar to other mangrove habitat in NW Mexico. Litterfall was highest from May to October for both species. Litterfall production was also higher overall in 2012 in comparison to 2013, possibly corresponding with meteorological differences, most notably wind conditions. Annual litterfall production was similar by species across northern and southern Sinaloa. A contrast of the NDVI by site and species showed a wide interval, including low values for A. germinans, suggesting stress conditions for this species.

  11. Nutrient enrichment intensifies hurricane impact in scrub mangrove ecosystems in the Indian River Lagoon, Florida, USA.

    PubMed

    Feller, Ilka C; Dangremond, Emily M; Devlin, Donna J; Lovelock, Catherine E; Proffitt, C Edward; Rodriguez, Wilfrid

    2015-11-01

    Mangroves are an ecological assemblage of trees and shrubs adapted to grow in intertidal environments along tropical, subtropical, and warm temperate coasts. Despite repeated demonstrations of their ecologic and economic value, multiple stressors including nutrient over-enrichment threaten these and other coastal wetlands globally. These ecosystems will be further stressed if tropical storm intensity and frequency increase in response to global climate changes. These stressors will likely interact, but the outcome of that interaction is uncertain. Here, we examined potential interaction between nutrient over-enrichment and the September 2004 hurricanes. Hurricanes Frances and Jeanne made landfall along Florida's Indian River Lagoon and caused extensive damage to a long-term fertilization experiment in a mangrove forest, which previously revealed that productivity was nitrogen (N) limited across the forest and, in particular, that N enrichment dramatically increased growth rates and aboveground biomass of stunted Avicennia germinans trees in the interior scrub zone. During the hurricanes, these trees experienced significant defoliation with three to four times greater reduction in leaf area index (LAI) than control trees. Over the long-term, the +N scrub trees took four years to recover compared to two years for controls. In the adjacent fringe and transition zones, LAI was reduced by > 70%, but with no differences based on zone or fertilization treatment. Despite continued delayed mortality for at least five years after the storms, LAI in the fringe and transition returned to pre-hurricane conditions in two years. Thus, nutrient over-enrichment of the coastal zone will increase the productivity of scrub mangroves, which dominate much of the mangrove landscape in Florida and the Caribbean; however, that benefit is offset by a decrease in their resistance and resilience to hurricane damage that has the potential to destabilize the system.

  12. Controls on the Chemical Hydrology and Associated Ecological Structure and Function in Mangroves, Indian River Lagoon, Florida

    NASA Astrophysics Data System (ADS)

    Stringer, C. E.; Rains, M. C.; Kruse, S.; Whigham, D.; Verhoeven, J. T.; Laanbroek, R.

    2008-12-01

    Recent studies indicate that hydrological processes control many aspects of ecosystem structure and function in mangroves. In this study, we are examining controls on the physical and chemical hydrology and subsequent physical and chemical hydrological controls on species composition, primary productivity, and nutrient cycling in mangroves on a barrier island in the Indian River Lagoon on the east-central coast of Florida. Salinities vary spatially, with surface-water and groundwater salinities ranging from ~10 in the upland, to ~30 in the regularly-flushed mangroves, to ~75 in the irregularly-flushed mangroves. However, salinities do not vary temporally, with no significant differences in salinities at given locations between the wet and dry seasons. Cation and anion concentrations and stable isotope ratios indicate that surface-water and groundwater salinities are largely controlled by evaporative enrichment. Resistivity and electromagnetic geophysical surveys further show that a freshwater lens is restricted to the upland and that great-than- seawater salinities extend to depths of greater than 20 m below the mangrove. These results indicate that precipitation and lagoon water mix and evapoconcentrate in the mangrove, and that this evapoconcentrated water sinks to form the thick layer of greater-than-seawater-salinity water below the mangrove. Spatial variations in species composition correlate with spatial variations in salinities, with maritime hammock, red mangrove, dense black mangrove, sparse black mangrove, and salt pan habitats being arranged on a gradient of increasing salinities. Spatial variations in primary productivity and nutrient cycling also correlate with spatial variations in salinities, though the relationships are in some cases less clear. For example, denitrification rates are lowest in the areas with salinities of approximately 30 and 75, corresponding with red mangrove and salt pan habitats, respectively, and are highest in areas with

  13. Multivariate and Geoaccumulation Index evaluation in mangrove surface sediment of Mengkabong lagoon, Sabah.

    PubMed

    Praveena, S M; Ahmed, A; Radojevic, M; Abdullah, M H; Aris, A Z

    2008-07-01

    Spatial variations in estuarine intertidal sediment have been often related to such environmental variables as salinity, sediment types, heavy metals and base cations. However, there have been few attempts to investigate the difference condition between high and low tides relationships and to predict their likely responses in an estuarine environment. This paper investigates the linkages between environmental variables and tides of estuarine intertidal sediment in order to provide a basis for describing the effect of tides in the Mengkabong lagoon, Sabah. Multivariate statistical technique, principal components analysis (PCA) was employed to better interpret information about the sediment and its controlling factors in the intertidal zone. The calculation of Geoaccumulation Index (I(geo)) suggests the Mengkabong mangrove sediments are having background concentrations for Al, Cu, Fe, and Zn and unpolluted for Pb. Extra efforts should therefore pay attention to understand the mechanisms and quantification of different pathways of exchange within and between intertidal zones.

  14. Satellite Images Analysis of Temporal Change (1979-2000) of the Mangrove Covertures that Surround the Mandinga Coastal Lagoon, Mexico.

    NASA Astrophysics Data System (ADS)

    Aldeco-Ramírez, J.; Cervantes-Candelas, A.

    2007-05-01

    Knowledge about the historical condition of the resources and the risk of natural hazards is an urgent necessity in developing countries. Satellite images analysis was applied in this study in order to evaluate coverture changes between 1979 and 2000. Mangroves cover large areas of coastal lagoon shoreline in the tropics and subtropics where they are important components in the productivity and integrity of their ecosystems. Visual and digital analysis of satellite images have been applied since the seventies when the first Land sat satellite was put in orbit. The digital analysis technique is mainly based on the reflectance or spectral response of the different objects laid on the earth surface as captured by the satellite. The results are useful for the environmental assessment of natural resources as forest and crops, and the quantification of hazards as fires, plagues, deforestation and urban expansion. This research surveys satellite images from the Mandinga Lagoon System, a coastal lagoon located to the south of the main port of Veracruz (19.1N, 96.1W), during three periods: 1989 1999 and 2000. The mangrove foliar cover was analyzed throughout the time. The reflectance signal of the mangrove that encircles the lagoon was taken as a base line for reference. The normalized difference vegetation index (NDVI) was computed in order to classify the vegetal coverage along the time. From our analysis we obtained that from 1979 to 1990 and from 1990 to 2000 areas of 122 hectares (approx. 305 acres) and 202 hectares (approx. 505 acres) were lost, respectively. The rates of mangrove trimming of 11.1 and 20.2 hectares yr-1 are high compared with other coastal lagoons of Mexico. The main causes of this deforestation are also discussed along with other factors as, the change of use of land and the fishery declination.

  15. Methane Cycling and Flux in Mangrove Ecosystems: A Comparison of Natural and Impacted Coastal Lagoons on the Yucatan Peninsula, Mexico

    NASA Astrophysics Data System (ADS)

    Young, M.; Paytan, A.; Miller, L.

    2001-12-01

    Tropical and subtropical wetlands are thought to be the dominant natural source of methane to the atmosphere, and mangrove ecosystems cover approximately 170,000 square kilometers of tropical and sub-tropical land, and dominating approximately 75 percent of the coastline between 25 degrees N and 25 degrees S. Previous studies have shown extremely wide ranges of methane flux from mangrove ecosystems, and have indicated that anthropogenic disturbances such as pollution, sewage discharge, and alteration of freshwater influx can have significant impacts on methane flux from mangrove ecosystems. Due to rapid population growth in tropical and sub-tropical areas and increasing impacts to coastal zones, it is important to obtain information regarding both natural and anthropogenic factors influencing methane cycling and flux within mangrove ecosystems, and to create a better estimate of the contribution of mangrove ecosystems to the global methane budget. Sampling for this study was conducted in three tropical coastal lagoons surrounded by mangrove vegetation located on the Yucatan Peninsula, Mexico. The three lagoons, Chelem, Celestun, and Terminos have similar vegetation and underlying geology, and are affected by similar seasonal patterns of temperature and precipitation. Significant differences in groundwater discharge and type and extent of anthropogenic impacts exist between the three lagoons. Chelem has moderate to low pollution and little to no ground water discharge. Celestun has very little pollution and large ground water discharges, while Terminos has relatively high impacts from pollution and human disturbance and varying ground water discharge. Previously reported data from these lagoons show distinct differences in methane concentrations in the sediment and water from Chelem in comparison to the concentrations measured in Celestun. Data collected over three seasons from Chelem and Celestun will be presented, providing information about seasonal variability

  16. Structure, Aboveground Biomass, and Soil Characterization of Avicennia marina in Eastern Mangrove Lagoon National Park, Abu Dhabi

    NASA Astrophysics Data System (ADS)

    Alsumaiti, Tareefa Saad Sultan

    Mangrove forests are national treasures of the United Arab Emirates (UAE) and other arid countries with limited forested areas. Mangroves form a crucial part of the coastal ecosystem and provide numerous benefits to society, economy, and especially the environment. Mangrove trees, specifically Avicennia marina, are studied in their native habitat in order to characterize their population structure, aboveground biomass, and soil properties. This study focused on Eastern Mangrove Lagoon National Park in Abu Dhabi, which was the first mangrove protected area to be designated in UAE. In situ measurements were collected to estimate Avicennia marina status, mortality rate (%), height (m), crown spread (m), stem number, diameter at breast height (cm), basal area (m), and aboveground biomass (t ha-1 ). Small-footprint aerial light detection and ranging (LIDAR) data acquired by UAE were processed to characterize mangrove canopy height and aboveground biomass density. This included extraction of LIDAR-derived height percentile statistics, segmentation of the forest into structurally homogenous units, and development of regression relationships between in situ reference and remote sensing data using a machine learning approach. An in situ soil survey was conducted to examine the soils' physical and chemical properties, fertility status, and organic matter. The data of soil survey were used to create soil maps to evaluate key characteristics of soils, and their influence on Avicennia marina in Eastern Mangrove Lagoon National Park. The results of this study provide new insights into Avicennia marina canopy population, structure, aboveground biomass, and soil properties in Abu Dhabi, as data in such arid environments is lacking. This valuable information can help in managing and preserving this unique ecosystem.

  17. Anthropogenic organic contaminants in water, sediments and benthic organisms of the mangrove-fringed Segara Anakan Lagoon, Java, Indonesia.

    PubMed

    Dsikowitzky, Larissa; Nordhaus, Inga; Jennerjahn, Tim C; Khrycheva, Polina; Sivatharshan, Yoganathan; Yuwono, Edy; Schwarzbauer, Jan

    2011-04-01

    Segara Anakan, a mangrove-fringed coastal lagoon in Indonesia, has a high diversity of macrobenthic invertebrates and is increasingly affected by human activities. We found > 50 organic contaminants in water, sediment and macrobenthic invertebrates from the lagoon most of which were polycyclic aromatic compounds (PACs). Composition of PACs pointed to petrogenic contamination in the eastern lagoon. PACs mainly consisted of alkylated PAHs, which are more abundant in crude oil than parent PAHs. Highest total PAC concentration in sediment was above reported toxicity thresholds for aquatic invertebrates. Other identified compounds derived from municipal sewage and also included novel contaminants like triphenylphosphine oxide. Numbers of stored contaminants varied between species which is probably related to differences in microhabitat and feeding mode. Most contaminants were detected in Telescopium telescopium and Polymesoda erosa. Our findings suggest that more attention should be paid to the risk potential of alkylated PAHs, which has hardly been addressed previously.

  18. Methane and sulfate dynamics in sediments from mangrove-dominated tropical coastal lagoons, Yucatan, Mexico

    USGS Publications Warehouse

    Chuang, P. C.; Young, Megan B.; Dale, Andrew W.; Miller, Laurence G.; Herrera-Silveira, Jorge A.; Paytan, Adina

    2016-01-01

    Porewater profiles in sediment cores from mangrove-dominated coastal lagoons (Celestún and Chelem) on the Yucatán Peninsula, Mexico, reveal the widespread coexistence of dissolved methane and sulfate. This observation is interesting since dissolved methane in porewaters is typically oxidized anaerobically by sulfate. To explain the observations we used a numerical transport-reaction model that was constrained by the field observations. The model suggests that methane in the upper sediments is produced in the sulfate reduction zone at rates ranging between 0.012 and 31 mmol m−2 d−1, concurrent with sulfate reduction rates between 1.1 and 24 mmol SO42− m−2 d−1. These processes are supported by high organic matter content in the sediment and the use of non-competitive substrates by methanogenic microorganisms. Indeed sediment slurry incubation experiments show that non-competitive substrates such as trimethylamine (TMA) and methanol can be utilized for microbial methanogenesis at the study sites. The model also indicates that a significant fraction of methane is transported to the sulfate reduction zone from deeper zones within the sedimentary column by rising bubbles and gas dissolution. The shallow depths of methane production and the fast rising methane gas bubbles reduce the likelihood for oxidation, thereby allowing a large fraction of the methane formed in the sediments to escape to the overlying water column.

  19. Impacts of mangrove density on surface sediment accretion, belowground biomass and biogeochemistry in Puttalam Lagoon, Sri Lanka

    USGS Publications Warehouse

    Phillips, D.H.; Kumara, M.P.; Jayatissa, L.P.; Krauss, Ken W.; Huxham, M.

    2017-01-01

    Understanding the effects of seedling density on sediment accretion, biogeochemistry and belowground biomass in mangrove systems can help explain ecological functioning and inform appropriate planting densities during restoration or climate change mitigation programs. The objectives of this study were to examine: 1) impacts of mangrove seedling density on surface sediment accretion, texture, belowground biomass and biogeochemistry, and 2) origins of the carbon (C) supplied to the mangroves in Palakuda, Puttalam Lagoon, Sri Lanka. Rhizophora mucronata propagules were planted at densities of 6.96, 3.26, 1.93 and 0.95 seedlings m−2along with an unplanted control (0 seedlings m−2). The highest seedling density generally had higher sediment accretion rates, finer sediments, higher belowground biomass, greatest number of fine roots and highest concentrations of C and nitrogen (N) (and the lowest C/N ratio). Sediment accretion rates, belowground biomass (over 1370 days), and C and N concentrations differed significantly between seedling densities. Fine roots were significantly greater compared to medium and coarse roots across all plantation densities. Sulphur and carbon stable isotopes did not vary significantly between different density treatments. Isotope signatures suggest surface sediment C (to a depth of 1 cm) is not derived predominantly from the trees, but from seagrass adjacent to the site.

  20. Survival of Salmonella enterica in aerated and nonaerated wastewaters from dairy lagoons

    USDA-ARS?s Scientific Manuscript database

    Salmonella is the most commonly identified foodborne pathogen in produce, meat and poultry. Cattle are known reservoirs of Salmonella and the pathogen excreted in feces end up in manure flush lagoons. Salmonella enterica survival was monitored in wastewater from on-site holding lagoons equipped with...

  1. Survival of Salmonella enterica in aerated and nonaerated wastewaters from dairy lagoons.

    PubMed

    Ravva, Subbarao V; Sarreal, Chester Z

    2014-10-29

    Salmonella is the most commonly identified foodborne pathogen in produce, meat and poultry. Cattle are known reservoirs of Salmonella and the pathogen excreted in feces ends up in manure flush lagoons. Salmonella enterica survival was monitored in wastewater from on-site holding lagoons equipped or not with circulating aerators at two dairies. All strains had poor survival rates and none proliferated in waters from aerated or settling lagoons. Populations of all three Salmonella serovars declined rapidly with decimal reduction times (D) of <2 days in aerated microcosms prepared from lagoon equipped with circulators. Populations of Salmonella decreased significantly in aerated microcosms (D = 4.2 d) compared to nonaerated waters (D = 7.4 d) and in summer (D = 3.4 d) compared to winter (D = 9.0 d). We propose holding the wastewater for sufficient decimal reduction cycles in lagoons to yield pathogen-free nutrient-rich water for crop irrigations and fertilization.

  2. Survival of Salmonella enterica in Aerated and Nonaerated Wastewaters from Dairy Lagoons

    PubMed Central

    Ravva, Subbarao V.; Sarreal, Chester Z.

    2014-01-01

    Salmonella is the most commonly identified foodborne pathogen in produce, meat and poultry. Cattle are known reservoirs of Salmonella and the pathogen excreted in feces ends up in manure flush lagoons. Salmonella enterica survival was monitored in wastewater from on-site holding lagoons equipped or not with circulating aerators at two dairies. All strains had poor survival rates and none proliferated in waters from aerated or settling lagoons. Populations of all three Salmonella serovars declined rapidly with decimal reduction times (D) of <2 days in aerated microcosms prepared from lagoon equipped with circulators. Populations of Salmonella decreased significantly in aerated microcosms (D = 4.2 d) compared to nonaerated waters (D = 7.4 d) and in summer (D = 3.4 d) compared to winter (D = 9.0 d). We propose holding the wastewater for sufficient decimal reduction cycles in lagoons to yield pathogen-free nutrient-rich water for crop irrigations and fertilization. PMID:25358096

  3. Distribution and Normalization of Heavy Metal Concentrations in Mangrove and Lagoonal Sediments from Mazatlán Harbor (SE Gulf of California)

    NASA Astrophysics Data System (ADS)

    Soto-Jiménez, M. F.; Páez-Osuna, F.

    2001-09-01

    Concentrations of heavy metals, carbonates, organic carbon and granulometry were examined in sediments from 60 sites within Mazatlán Harbor and adjacent areas. Regional distribution had a strong (for Al, Fe, Li and Ni) and weak (for Cd, Co, Cr, Pb, V and Zn) seaward concentration gradient decreasing from the upper lagoon. The highest concentrations for most metals occurred in fine-grained sediments from Infiernillo Estuary, the upper lagoon and the industrial zone. In contrast, lower levels were usually found in the sandy sediments of the navigation channel, port entrance and an area associated with sewage outfall. Analysis of transects in mangrove and lagoonal sediments indicated that the amount of fine material and organic carbon increases towards the margins where mangrove sediments exist. While metal variations were not clearly observed in most of the metals examined; only Ni, V, Pb and Cu showed a slight tendency to increase towards the margins. Sometimes lagoonal sediments had redox and texture characteristics comparable to those from mangrove substrate, thus competing because of a similar capture capacity of metals. Metal data were normalized against Al and Li using a combination of normalization techniques (95% prediction intervals, regional anomalies and enrichment factor). It was found that Al and Li were good normalizers for most of the examined metals and they are important constituents of one or more of the major fine-grained heavy metal carrier(s) and adequately reflect the granulometric variability in the sediments of the study area.

  4. Methane and sulfate dynamics in sediments from mangrove-dominated tropical coastal lagoons, Yucatán, Mexico

    NASA Astrophysics Data System (ADS)

    Chuang, P.-C.; Young, M. B.; Miller, L. G.; Herrera-Silveira, J. A.; Paytan, A.

    2015-11-01

    Methane, sulfate and chloride concentrations in sediment porewater from two coastal mangrove ecosystems (Celestún and Chelem Lagoons) on the Yucatán Peninsula, Mexico were measured. In these sediments methane exists in shallow sediments where sulfate is not depleted, and sulfate reduction is actively occurring. A transport-reaction model depicting the various production and consumption processes for methane and sulfate is used to elucidate processes responsible for this observation. The model illustrates that methane in the upper sediments is produced in-situ supported by high dissolved organic matter as well as by non-competitive substrates. In addition methane is contributed to porewater in the upper sediments, where sulfate reduction occurs, by transport from deeper zones within the sedimentary column through bubbles dissolution and diffusion. The shallow methane production and accumulation depths in these sediments promote high methane fluxes to the water column and atmosphere.

  5. The Assessment of Mangrove Sediment Quality in Mengkabong Lagoon: An Index Analysis Approach

    ERIC Educational Resources Information Center

    Praveena, Sarva M.; Radojevic, Miroslav; Abdullah, Mohd H.

    2007-01-01

    The objectives of this study are to use different types of indexes to assess the current pollution status in Mengkabong lagoon and select the best index to describe the Mengkabong sediment quality. The indexes used in this study were Enrichment Factor (EF), Geo-accumulation Index (Igeo), Pollution Load Index (PLI) and Marine Sediment Pollution…

  6. Relationships Between Vegetation and Ground Conductivity in a Mangrove Near Indian River Lagoon, Florida

    NASA Astrophysics Data System (ADS)

    McNiff, C. M.; Kruse, S. E.; Rains, M. C.; Stringer, C. E.

    2013-12-01

    In this study, an electromagnetic induction survey was conducted with the EM-31 to assess the spatial variability of ground conductivity, a proxy for groundwater salinity, in a mangrove on North Hutchinson Island, Florida, a carbonate barrier island. A previous study established a relationship between ground conductivities and pore-water salinities, but data points are not spaced closely enough to properly observe the potential effect of mangrove vegetation on ground conductivities. We present here apparent conductivities measured along five profiles that traverse the field site; data were inverted to obtain ground conductivity for the vadose and saturated zones. The vegetation types are dense black mangrove, scrubby black mangrove and salt pan (little or no vegetation). At this site, average water-table levels were 0.2 m below ground level. The mangrove roots systems extend to .6 m to 1 m below the ground surface. Sampled pore-water conductivities range from near freshwater to hypersaline. Effective depth measurements range from 2 m to 5.5 m for the EM31. The average vadose-zone ground conductivities derived from inversion of the data are 1400 mS/m, but range from 75 mS/m to 12,000mS/m. The average saturated -zone ground conductivities are 1900 mS/m, and range more narrowly from 820 mS/m to 2400 mS/m. These large conductivity values mean the low-induction number assumption is not satisfied so true conductivity values are larger than what is measured, but spatial distribution and variability is still observable. There is a larger degree of variability observed in the vadose zone than the saturated zone, but the saturated zone generally has higher conductivity values associated with it; which is controlled by saline-hypersaline groundwater. The density of mangrove vegetation shows a strong correlation with ground conductivity variability in both zones-- vegetated areas have more variability than salt pan areas. This is due to root systems removing salt and water

  7. Methane and sulfate dynamics in sediments from mangrove-dominated tropical coastal lagoons, Yucatán, Mexico

    NASA Astrophysics Data System (ADS)

    Chuang, Pei-Chuan; Young, Megan B.; Dale, Andrew W.; Miller, Laurence G.; Herrera-Silveira, Jorge A.; Paytan, Adina

    2016-05-01

    Porewater profiles in sediment cores from mangrove-dominated coastal lagoons (Celestún and Chelem) on the Yucatán Peninsula, Mexico, reveal the widespread coexistence of dissolved methane and sulfate. This observation is interesting since dissolved methane in porewaters is typically oxidized anaerobically by sulfate. To explain the observations we used a numerical transport-reaction model that was constrained by the field observations. The model suggests that methane in the upper sediments is produced in the sulfate reduction zone at rates ranging between 0.012 and 31 mmol m-2 d-1, concurrent with sulfate reduction rates between 1.1 and 24 mmol SO42- m-2 d-1. These processes are supported by high organic matter content in the sediment and the use of non-competitive substrates by methanogenic microorganisms. Indeed sediment slurry incubation experiments show that non-competitive substrates such as trimethylamine (TMA) and methanol can be utilized for microbial methanogenesis at the study sites. The model also indicates that a significant fraction of methane is transported to the sulfate reduction zone from deeper zones within the sedimentary column by rising bubbles and gas dissolution. The shallow depths of methane production and the fast rising methane gas bubbles reduce the likelihood for oxidation, thereby allowing a large fraction of the methane formed in the sediments to escape to the overlying water column.

  8. Nitrogen limitation of growth and nutrient dynamics in a disturbed mangrove forest, Indian River Lagoon, Florida

    USGS Publications Warehouse

    Feller, Ilka C.; Whigham, D.F.; McKee, K.L.; Lovelock, C.E.

    2003-01-01

    The objectives of this study were to determine effects of nutrient enrichment on plant growth, nutrient dynamics, and photosynthesis in a disturbed mangrove forest in an abandoned mosquito impoundment in Florida. Impounding altered the hydrology and soil chemistry of the site. In 1997, we established a factorial experiment along a tree-height gradient with three zones, i.e., fringe, transition, dwarf, and three fertilizer treatment levels, i.e., nitrogen (N), phosphorus (P), control, in Mosquito Impoundment 23 on the eastern side of Indian River. Transects traversed the forest perpendicular to the shoreline, from a Rhizophora mangle-dominated fringe through an Avicennia germinans stand of intermediate height, and into a scrub or dwarf stand of A. germinans in the hinterland. Growth rates increased significantly in response to N fertilization. Our growth data indicated that this site is N-limited along the tree-height gradient. After 2 years of N addition, dwarf trees resembled vigorously growing saplings. Addition of N also affected internal dynamics of N and P and caused increases in rates of photosynthesis. These findings contrast with results for a R. mangle-dominated forest in Belize where the fringe is N-limited, but the dwarf zone is P-limited and the transition zone is co-limited by N and P. This study demonstrated that patterns of nutrient limitation in mangrove ecosystems are complex, that not all processes respond similarly to the same nutrient, and that similar habitats are not limited by the same nutrient when different mangrove forests are compared.

  9. Nitrogen limitation of growth and nutrient dynamics in a disturbed mangrove forest, Indian River Lagoon, Florida.

    PubMed

    Feller, Ilka C; Whigham, Dennis F; McKee, Karen L; Lovelock, Catherine E

    2003-02-01

    The objectives of this study were to determine effects of nutrient enrichment on plant growth, nutrient dynamics, and photosynthesis in a disturbed mangrove forest in an abandoned mosquito impoundment in Florida. Impounding altered the hydrology and soil chemistry of the site. In 1997, we established a factorial experiment along a tree-height gradient with three zones, i.e., fringe, transition, dwarf, and three fertilizer treatment levels, i.e., nitrogen (N), phosphorus (P), control, in Mosquito Impoundment 23 on the eastern side of Indian River. Transects traversed the forest perpendicular to the shoreline, from a Rhizophora mangle-dominated fringe through an Avicennia germinans stand of intermediate height, and into a scrub or dwarf stand of A. germinans in the hinterland. Growth rates increased significantly in response to N fertilization. Our growth data indicated that this site is N-limited along the tree-height gradient. After 2 years of N addition, dwarf trees resembled vigorously growing saplings. Addition of N also affected internal dynamics of N and P and caused increases in rates of photosynthesis. These findings contrast with results for a R. mangle-dominated forest in Belize where the fringe is N-limited, but the dwarf zone is P-limited and the transition zone is co-limited by N and P. This study demonstrated that patterns of nutrient limitation in mangrove ecosystems are complex, that not all processes respond similarly to the same nutrient, and that similar habitats are not limited by the same nutrient when different mangrove forests are compared.

  10. Bioavailability of cadmium, copper, mercury, lead, and zinc in subtropical coastal lagoons from the southeast Gulf of California using mangrove oysters (Crassostrea corteziensis and Crassostrea palmula).

    PubMed

    Páez-Osuna, Federico; Osuna-Martínez, Carmen C

    2015-02-01

    Cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn) were assessed in the edible tissues of Crassrotrea corteziensis oysters collected during the rainy and dry seasons in 27 sites from 8 coastal lagoons of the southeast Gulf of California. In addition, C. palmula oysters were sampled at 9 sites from the same mangrove roots where C. corteziensis oysters were collected. Metal analyses were performed by flame atomic absorption spectrophotometry (Cd, Cu, and Zn), graphite furnace (Pb), and cold vapor detection (Hg). The obtained mean levels were (µg g(-1) dry weight) as follows: Cd 6.05 ± 2.77, Cu 60.0 ± 33.4, Hg 0.38 ± 0.17, Pb 1.11 ± 0.63, and Zn 777 ± 528 µg g(-1). For all metals except Hg, the concentrations were greater during dry season than during rainy seasons. The high levels, particularly that for Cd, were related to upwelling along the eastern Gulf of California. High Hg levels in the rainy season were associated with the transport of materials from the watershed to the lagoon. Shrimp farming, agriculture, and other sources were considered as potential sources to explain the differences in metal bioavailability in the 8 lagoons. The mean concentrations of Cd (Santa María-La Reforma lagoon), Cu [San Ignacio-Navachiste-El Macapule (SINM), Urías (URI), and Altata-Ensenada del Pabellón lagoons], and zinc (Zn) (URI, Santa María-Ohuira-Topolobampo, El Colorado, and SINM lagoons) during the dry season were greater than the maximum permissible limits. C. palmula collected in 8 sites where they were present simultaneously with C. corteziensis had consistently greater metal levels than C. corteziensis, but correlation analyses showed a high and significant (P < 0.05) correlation between metal concentrations in both species. The correlation equations obtained are useful where the same species is not distributed and is necessary to compare results from distinct regions.

  11. [Spatial-temporal variation of the macroinvertebrate epibiont community on red mangrove prop roots Rhizophora mangle (Rhizophoraceae) at La Mancha coastal lagoon, Veracruz, Mexico].

    PubMed

    Ruiz, Marcela; López-Portillo, Jorge

    2014-12-01

    La Mancha lagoon is connected to the Gulf of Mexico through an estuarine ephemeral inlet, a sand bar, which opens during the rainy season and closes during the late fall and the winter storm season. As the lagoon fills up with the permanent stream flow into its Southern part, the water level increases and the sand bar opens up, releasing huge volumes of water into the ocean and leaving the previously flooded intertidal zone exposed to drying. In this study, we described the spatial and temporal variations of structure and composition of the community living on the surface of red mangrove prop roots, related to the hydrodynamic of the estuarine inlet. Four red mangrove prop roots were collected every three months, over an annual period, at ten sampling stations. Water temperature, salinity, dissolved oxygen, water depth and transparency were also measured at each sampling event. To describe the identity, abundance, biomass, and specific richness of epibiont coverage on the prop roots, measurements were taken at 10 cm intervals (herein called "horizons"). A total of 59,632 specimens and a total biomass of 172 g/cm2 were registered, and a maximum of eleven horizons presented at least one" species of epibionts. Two species of polychaetes, 12 of mollusks and 14 of crustaceans were identified, with Mytilopsis leucophaeata as the most abundant, Ficopomatus miamiensis as the most common and Crassostrea rhizophorae with the highest contribution in biomass. Sampling effort was assessed using species accumulation curves, resulting that the efficiency was, in general, greater than 90% of the richness predicted by asymptotic models. The hydrodynamics of the estuarine inlet had a great influence on the environmental conditions of the lagoon and on the spatial and temporal variation of the epibiont community: (a) when the inlet is open, there is a North-South gradient in environmental parameters (b) when the inlet is closed and the water level increases, the epibionts especially

  12. Arsenic and mercury contamination of sediments of geothermal springs, mangrove lagoon and the Santispac bight, Bahía Concepción, Baja California peninsula.

    PubMed

    Leal-Acosta, María Luisa; Shumilin, Evgueni; Mirlean, Nicolai; Sapozhnikov, Dmitry; Gordeev, Vyacheslav

    2010-12-01

    In order to find out the environmental impact on the coastal zone, the composition of sediments of the intertidal geothermal hot spring zone and adjacent area of Playa Santispac in the pristine Bahía Concepción (Baja California peninsula) was studied. High concentrations of As (13-111 mg kg⁻¹) and Hg (0.55-25.2 mg kg⁻¹) were found in the sediments of the geothermal sources. Arsenic and Hg concentrations decrease rapidly in the adjacent small mangrove lagoon sediments and reach background levels (0.7-2.6 mg kg⁻¹ and 6-60 μg kg⁻¹ respectively) in the marine sediments collected in front of Playa Santispac.

  13. Biomonitoring of arsenic through mangrove oyster (Crassostrea corteziensis Hertlein, 1951) from coastal lagoons (SE Gulf of California): occurrence of arsenobetaine and other arseno-compounds.

    PubMed

    Bergés-Tiznado, Magdalena E; Páez-Osuna, Federico; Notti, Alessandra; Regoli, Francesco

    2013-09-01

    In this study, we examined the bioavailability of arsenic through the mangrove oyster Crassostrea corteziensis sampled from seven coastal lagoons in SE Gulf of California during the rainy and dry seasons. As concentrations in soft tissue of oysters C. corteziensis fluctuated between 5.2 and 11.6 μg/g on dry weight; organisms from the control site presented the lowest As concentrations in the two sampling seasons. As speciation was evaluated in selected samples and indicated that arsenobetaine was the major arseno-compound accounting for 53.5-74.7 % of total As. Lower percentage contributions were obtained for nonextractable As (9.7-25.5 %) and other molecules such as arsenocholine and methyl-arsonate (<5 %). Inorganic As was detectable in only two samples, at concentrations lower than 0.1 μg/g. These As data are the first generated in NW Mexico and indicate that C. corteziensis is safe for human consumption in terms of arseno-compounds. It is evident that As bioavailability in these lagoons is low.

  14. [Abundance and richness of mollusks and crustaceans associated to the submerged roots of red mangrove (Rhizophora mangle) at Bocaripo Lagoon, Sucre, Venezuela].

    PubMed

    Cedeño, Jennellis; Jiménez Prieto, Mayré; Pereda, Luisana; Allen, Thays

    2010-10-01

    Mangrove roots are important habitats for many species. The abundance and richness of mollusks and crustaceans associated with the roots demerged of Rhizophora mangle was studied. The samples were gathered between February 2005 and January 2006, in Bocaripo lagoon, north coast of Sucre state, Venezuela. Five stations were established inside the lagoon; on every station two roots were chosen at random, put in plastic bags and scraped. The associated organisms were separated by taxa and fixed in 10% formaldehyde. One thousand ninety two specimens of mollusks, distributed in two classes: Bivalve and Gastropod were collected. Bivalve was the most abundant with 943 individuals. The most representative family was Mytilidae with 6 species, being Musculus lateralis the dominant species. The crustaceans were represented by 372 organisms, belonging to the class Malacostraca, where Panopeus herbstii (169 ind.) was the most abundant species. The families Panopeidae, Porcellanidae and Majidae had the highest number of species. Maximum abundance was in February (224 ind.), with a richness of 25 species and the minimums in November (45 ind.) and a richness of 12 species. The stations 1 and 5 presented the major abundance and richness of organisms, which could be related to environmental conditions favorable, as the major availability of microhabitats and nourishing offer; on the contrary the station 4, presented a more inhospitable environment, due to the high values in the salinity and temperature, which contributes with the minor abundance and richness of the present species.

  15. Food preferences of mangrove crabs related to leaf nitrogen compounds in the Segara Anakan Lagoon, Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Nordhaus, Inga; Salewski, Tabea; Jennerjahn, Tim C.

    2011-05-01

    The large amounts of leaf litter produced by tropical mangrove forests serve as a major food source for the benthic fauna. The reasons for the preferential consumption of mangrove leaves by crabs are unclear as yet. We investigated the diet, food preferences and consumption rates of 8 dominant grapsoid crab species ( Perisesarma spp., Episesarma spp., Metopograpsus latifrons, and Metaplax elegans) in mangroves of Segara Anakan, Java, Indonesia, by means of stomach-content analysis and feeding experiments. Leaves from the five most abundant mangrove tree species ( Aegiceras corniculatum, Avicennia alba, Ceriops decandra, Rhizophora apiculata, and Sonneratia caseolaris) were analyzed for organic carbon, total nitrogen, δ 13C, δ 15N and amino acids and hexosamines. This study is the first that investigated crab food preferences related to the nitrogen compound composition of leaves. Our results show that Episesarma spp. and Perisesarma spp. are omnivorous crabs which mainly feed on detritus, mangrove litter and bark, and on a small amount of roots, algae and animal matter whereas M. elegans is a detritus feeder. In feeding experiments with green, yellow and brown leaves Perisesarma spp. and E. singaporense had the highest consumption rates for brown leaves of R. apiculata and S. caseolaris, and for green leaves of A. alba. Preferred leaves were characterized by a high amount and/or freshness of nitrogenous compounds and their biochemical composition was significantly different from that of disliked leaves (all leaves of A. corniculatum and C. decandra, green and yellow leaves of R. apiculata and S. caseolaris). The presence of the hexosamine galactosamine found only in brown leaves indicates that bacteria contribute to the amount of bioavailable nitrogen compounds. We infer that the nitrogen compound composition rather than the C/N ratio alone is a determinant for bioavailability of mangrove leaves and hence may partly explain the crabs' food preferences.

  16. Cadmium, copper, lead and zinc contents of the mangrove oyster, Crassostrea corteziensis, of seven coastal lagoons of NW Mexico.

    PubMed

    Frías-Espericueta, M G; Osuna-López, I; Bañuelos-Vargas, I; López-López, G; Muy-Rangel, M D; Izaguirre-Fierro, G; Rubio-Carrasco, W; Meza-Guerrero, P C; Voltolina, D

    2009-10-01

    The ranges of concentrations of Cd, Cu, Pb and Zn of the soft tissues of C. corteziensis collected in seven coastal lagoons of NW Mexico were 1.55-7.45, 17.50-166.36, 4.13-9.49 and 245.34-2,304.12 microg/g (dry weight), respectively. Their distributions were not consistent and there were no seasonal trends, indicating different point sources of the metals in each lagoon. The mean Cd and Pb concentrations were 5.34 and 6.30 microg/g (dry weight), which are higher than the values indicative of polluted areas. Our data indicate that only the levels of Cd are a possible health risk in six of these lagoons, and only in the case of regular local consumers. In one, Cu and Zn reach levels of concern.

  17. Survival of Escherichia coli strains in Mediterranean brackish water in the Bizerte lagoon in northern Tunisia.

    PubMed

    Boukef, I; El Bour, M; Al Gallas, N; El Bahri, O; Mejri, S; Mraouna, R; Ben Aissa, R; Boudabous, A; Got, P; Troussellier, M

    2010-11-01

    This study investigated survival and virulence of Escherichia coli strains exposed to natural conditions in brackish water. Two E. coli strains (O126:B16 and O55:B5) were incubated in water microcosms in the Bizerte lagoon in northern Tunisia and exposed for 12 days to natural sunlight in June (231 to 386 W/m2, 26 +/- 1 degrees C, 30 g/L) and in April (227 to 330 W/m2, 17 +/- 1 degrees C, 27 g/L) or maintained in darkness for 21 days (17 +/- 1 degrees C, 27 g/L). The results revealed that sunlight was the most significant inactivating factor (decrease of 3 Ulog within 48 hours for the two strains) compared to salinity and temperature (in darkness). Survival time of the strains was prolonged as they were maintained in darkness. Local strain (E. coli O55:B5) showed better survival capacity (T90 = 52 hours) than E. coli O126:B16 (T90 = 11 h). For both, modifications were noted only for some metabolic activities of carbohydrates hydrolysis. Cytotoxicity of the two strains, tested on Vero cell, was maintained during the period of survival.

  18. Organic Carbon Loading in Tropical Near-Shore Ecosystems: the Role of Mangrove Lagoons and Channels in Coastal Ocean Acidification

    NASA Astrophysics Data System (ADS)

    García, E.; Morell, J. M.

    2016-02-01

    Low energy tropical Caribbean shores are often dominated by highly productive mangrove ecosystems that thrive on land borne inorganic nutrient inputs and whose net production results in significant export of litter and dissolved organic compounds (DOC). These organic matrixes can be effectively transported to nearby ecosystems, including coral reefs whose vulnerability to excessive organic loading has been widely documented. This study documents the seaward transport and transformation of organic carbon from mangrove bays, trough near-shore reef ecosystems and out to open waters in the La Parguera Marine Reserve (LPMR). Considering in-situ colored dissolved organic matter (CDOM) as a tracer for DOC, absorption coefficient values (a350) were observed in the 6.13-0.02 m-1 and 14.08-0.06 m-1 during the dry (from 0 to 0.18 inches of rain) and wet seasons (from 0.68 to 4.76 inches of rain), respectively. Spectral properties (S275-295 and SR) calculations indicate that DOC is predominantly of terrestrial origin and found in high concentrations in enclosed mangrove bays and canals. Data evidences a strong gradient in CDOM concentration decreasing t from inshore to outer shelf waters. Rain precipitation correlated well with high CDOM values (aλ values doubled) and forced LPMR to behave similarly to a river influenced estuary as shown when CDOM is correlated with salinity, contrary to its predominant negative estuary profile. When correlating CDOM with pH and dissolved oxygen concentrations, it is evident that high organic matter content is driving ocean acidification in the nearshore areas. The non-conservative behavior of CDOM implies that other processes besides dilution may play a significant role in its spatial distribution.

  19. Variations in the survival probabilities of the PVC-protected red mangrove propagules: testing the encased replanting technique.

    PubMed

    López-Ortiz, M I; Pérez, C M; Suárez, E; Ríos-Dávila, R

    1999-12-01

    The EcoEléctrica Mangrove Planting Project, a five-year voluntary effort, has the purpose of testing a recently developed mangrove planting technique at the EcoEléctrica site in Peñuelas, Puerto Rico. The goal of the project is to provide empirical validation to promote or improve the technique to be used in recovering mangrove ecosystems in Puerto Rico and United States. The research presented herein analyzed the information collected on the first two years of the project. The proportions of remaining casings and seeds per study zone were compared using the chi-square distribution. Zone 1 had the least pipes lost while Zone 4 had the most (p < 0.05). Forty-three percent of the seeds in Zone 1 remained in the casing, while 26% remained in Zone 2 (p = 0.03). Median growth rates of seeds per study zone showed that Zone 1 had the highest median growth rates. Survival analysis described the survival experience of the seeds, and differences in survival probabilities were compared with the log-rank test. Zone 1 seeds had a better survival experience compared to Zones 2, 3 and 4 (p < 0.0001). Survival probabilities for being free of spots were over 60% during the whole study period. No significant differences were observed in the survival experience with the use-or-no use of casing extensions (p = 0.40), and the use-or-no use of nursed seeds (p = 0.26). Differences in survival probabilities might be attributed to variations in wave energy, depth or substrate conditions. This hypothesis will be evaluated in the second phase of the study.

  20. Mangroves of Kiribati - A Priceless Resource Needs Protection

    Treesearch

    James Denny Ward

    1998-01-01

    Mangrove forests grow naturally along the ocean and lagoons on the islands of Kiribati. For centuries mangroves have provided wood for fuel, posts, poles, boats, houses, fences, walls, and furniture, and have been used to stake fish traps, to cultivate seaweed, and to dye and preserve canoe sails and clothing. Mangrove leaves and flowers are used in garlands and leis...

  1. Mangrove forests

    Treesearch

    Ariel E. Lugo; Ernesto. Medina

    2014-01-01

    The mangrove environment is not globally homogeneous, but involves many environmental gradients to which mangrove species must adapt and overcome to maintain the familiar structure and physiognomy associated with the mangrove ecosystem. The stature of mangroves, measured by tree height, decreases along the following environmental gradients from low to high salinity,...

  2. Assessing the influence of artificially constructed channels in the growth of afforested black mangrove (Avicennia germinans) within an arid coastal region.

    PubMed

    Flores-Verdugo, F; Zebadua-Penagos, F; Flores-de-Santiago, F

    2015-09-01

    Hypersaline conditions are common in sub-tropical latitudes where freshwater availability is seasonal. Hence, hydroperiod plays a crucial role in providing a suitable area for the establishment of new mangrove seedlings. The purpose of this study was to assess the function of hydrological change and irradiance in the growth of afforested black mangrove (Avicennia germinans) along the upper saltpan area by creating six channels of 1 m wide by 0.3 deep and 30 m length. All channels were constructed perpendicular to the main coastline of the Urias lagoon, Pacific coast of Mexico. Seedlings of black mangrove were planted along four of the channels. After ten months, the pore-water salinity concentration within the six channels was reduced by half. Results indicate that there were no significant differences (P > 0.05) in mangrove survival among the channels. However, the optimal growth of black mangroves was near the channels edge. The growth of mangrove seedlings planted under 50% of solar attenuation was 10 times higher as compared to mangroves under direct sunlight. This study shows the feasibility of using channels to enhance tidal flow and decrease hypersaline conditions for future afforestation endeavors in arid coastlines.

  3. Mangrove postcard

    USGS Publications Warehouse

    Ball, Lianne C.

    2016-07-14

    Mangrove ecosystems protect vulnerable coastlines from storm effects, recycle nutrients, stabilize shorelines, improve water quality, and provide habitat for commercial and recreational fish species as well as for threatened and endangered wildlife. U.S. Geological Survey scientists conduct research on mangrove ecosystems to provide reliable scientific information about their ecology, productivity, hydrological processes, carbon storage stress response, and restoration success. The Mangrove Science Network is a collaboration of USGS scientists focused on working with natural resource managers to develop and conduct research to inform decisions on mangrove management and restoration. Information about the Mangrove Science Network can be found at: http://www.usgs.gov/ecosystems/environments/mangroves.html.

  4. Bioaccumulation and depuration of Zn and Cd in mangrove oysters (Crassostrea rhizophorae, Guilding, 1828) transplanted to and from a contaminated tropical coastal lagoon.

    PubMed

    Rebouças do Amaral, Maria Clara; de Freitas Rebelo, Mauro; Torres, João Paulo Machado; Pfeiffer, Wolfgang Christian

    2005-05-01

    In order to study Zn and Cd accumulation and depuration, a set of oysters, Crassostrea rhizophorae, were transplanted to a metal contaminated coastal lagoon and another one was harvested there and transplanted to a non-polluted site. C. rhizophorae oysters and Perna perna mussels native from both sites were collected in order to monitor variability of metal concentration in resident populations. After three months exposure, oysters transplanted to the polluted site accumulated fourfold Zn (307-1319 microgg(-1)) without reaching the concentration level of resident oysters (9770 microgg(-1)). Cadmium concentrations had a slight but significant decrease during the same period (1.25-0.54 microgg(-1)). Oysters transplanted to the non-polluted site, showed threefold Zn depuration (6727-2404 microgg(-1)), while Cd had no significant variation (0.90-1.45 microgg(-1)). Results showed that transplanted oysters do not reach heavy metal concentrations in indigenous populations suggesting transplanted organisms would be better used to evaluate bioavailability instead of environmental concentrations.

  5. Growth, Survival and Reproduction of the Giant Clam Tridacna maxima (Röding 1798, Bivalvia) in Two Contrasting Lagoons in French Polynesia

    PubMed Central

    Van Wynsberge, Simon; Andréfouët, Serge; Gaertner-Mazouni, Nabila; Wabnitz, Colette C. C.; Menoud, Mathilde; Le Moullac, Gilles; Levy, Peva; Gilbert, Antoine; Remoissenet, Georges

    2017-01-01

    Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity indices in June and July 2014, were timed with high oceanic water inflow and a decrease in lagoon water temperature. Secondly, temperature explained differences in shell growth rates between seasons and lagoons, generating different growth curves for the two sites. Thirdly, local mortality rates were also found to likely be related to water renewal patterns. In conclusion, our study suggests that reef aperture and lagoon water renewal rates play an integral role in giant clam life history, with significant differences in rates of shell growth, mortality and fertility found between open versus semi-closed atoll lagoons in coral reef ecosystems. PMID:28118406

  6. Growth, Survival and Reproduction of the Giant Clam Tridacna maxima (Röding 1798, Bivalvia) in Two Contrasting Lagoons in French Polynesia.

    PubMed

    Van Wynsberge, Simon; Andréfouët, Serge; Gaertner-Mazouni, Nabila; Wabnitz, Colette C C; Menoud, Mathilde; Le Moullac, Gilles; Levy, Peva; Gilbert, Antoine; Remoissenet, Georges

    2017-01-01

    Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity indices in June and July 2014, were timed with high oceanic water inflow and a decrease in lagoon water temperature. Secondly, temperature explained differences in shell growth rates between seasons and lagoons, generating different growth curves for the two sites. Thirdly, local mortality rates were also found to likely be related to water renewal patterns. In conclusion, our study suggests that reef aperture and lagoon water renewal rates play an integral role in giant clam life history, with significant differences in rates of shell growth, mortality and fertility found between open versus semi-closed atoll lagoons in coral reef ecosystems.

  7. Moxos' Lagoons

    NASA Astrophysics Data System (ADS)

    Belmonte, Juan Antonio; Barba, Josep F.

    There has been a long-standing debate on the anthropogenic origin of Moxos' lagoons. In the late 1990s, an analysis of the orientation of a comprehensive and statistically significant number of lagoons showed that only human action could explain the peculiarities of their geometry and especially their orientation according to a main axis aligned to an azimuth of 50° and its complementary angle. Besides, the absence of distinctive geographical marks in the horizon strongly suggested an astronomical justification for such peculiar pattern. Thus, the lagoons could have been deliberately orientated in agreement with certain stellar positions which may have marked special moments of the local climatic or economic cycle, a fact which might be confirmed in ethno-historic references.

  8. Soil Accretionary Dynamics, Sea-Level Rise and the Survival of Wetlands in Venice Lagoon: A Field and Modelling Approach

    NASA Astrophysics Data System (ADS)

    Day, J. W.; Rybczyk, J.; Scarton, F.; Rismondo, A.; Are, D.; Cecconi, G.

    1999-11-01

    Over the past century, Venice Lagoon (Italy) has experienced a high rate of wetland loss. To gain an understanding of the factors leading to this loss, from March 1993 until May 1996 the soil accretionary dynamics of these wetlands were studied. Vertical accretion, short term sedimentation, soil vertical elevation change and horizontal shoreline change were measured at several sites with varying sediment availability and wave energy. Short term sedimentation averaged 3-7 g dry m -2day -1per site with a maximum of 76 g m -2 day -1. The highest values were measured during strong pulsing events, such as storms and river floods, that mobilized and transported suspended sediments. Accretion ranged from 2-23 mm yr -1and soil elevation change ranged from -32 to 13·8 mm yr -1. The sites with highest accretion were near a river mouth and in an area where strong wave energy resuspended bottom sediments that were deposited on the marsh surface. A marsh created with dredged spoil had a high rate of elevation loss, probably due mainly to compaction. Shoreline retreat and expansion of tidal channels also occurred at several sites due to high wave energy and a greater tidal prism. The current rate of elevation gain at some sites was not sufficient to offset relative sea-level rise. The results suggest that reduction of wave energy and increasing sediment availability are needed to offset wetland loss in different areas of the lagoon. Using the data collected as part of this project, we developed a wetland elevation model designed to predict the effect of increasing rates of eustatic sea-level rise on wetland sustainability. The advantage of this model, in conjunction with measured short-term rates of soil elevation change, to determine sustainability is that the model integrates the effects of long term processes (e.g. compaction and decomposition) and takes into account feedback mechanisms that affect elevation. Specifically, changes in elevation can result in changes in

  9. Mangrove Swamps

    EPA Pesticide Factsheets

    Mangrove swamps are coastal wetlands found in tropical and subtropical regions. They are characterized by halophytic (salt loving) trees, shrubs and other plants growing in brackish to saline tidal waters.

  10. Altered protozoan and bacterial communities and survival of Escherichia coli O157:H7 in monensin-treated dairy wastewater from a dairy lagoon

    USDA-ARS?s Scientific Manuscript database

    We determined the role of native protozoa in controlling the populations of Escherichia coli O157:H7 (EcO157) in wastewater from dairy lagoons as both protozoa and EcO157 are released into lagoons through manure washings. We monitored the fate of an outbreak strain of EcO157 in wastewater treated wi...

  11. Altered Protozoan and Bacterial Communities and Survival of Escherichia coli O157:H7 in Monensin-Treated Wastewater from a Dairy Lagoon

    PubMed Central

    Ravva, Subbarao V.; Sarreal, Chester Z.; Mandrell, Robert E.

    2013-01-01

    Surviving predation is a fitness trait of Escherichia coli O157:H7 (EcO157) that provides ample time for the pathogen to be transported from reservoirs (e.g. dairies and feedlots) to farm produce grown in proximity. Ionophore dietary supplements that inhibit rumen protozoa may provide such a selective advantage for EcO157 to proliferate in lagoons as the pathogen is released along with the undigested supplement as manure washings. This study evaluated the fate of an outbreak strain of EcO157, protozoan and bacterial communities in wastewater treated with monensin. Although total protozoa and native bacteria were unaffected by monensin, the time for 90% decrease in EcO157 increased from 0.8 to 5.1 days. 18S and 16S rRNA gene sequencing of wastewater samples revealed that monensin eliminated almost all colpodean and oligohymenophorean ciliates, probably facilitating the extended survival of EcO157. Total protozoan numbers remained high in treated wastewater as monensin enriched 94% of protozoan sequences undetected with untreated wastewater. Monensin stimulated 30-fold increases in Cyrtohymena citrina, a spirotrichean ciliate, and also biflagellate bicosoecids and cercozoans. Sequences of gram-negative Proteobacteria increased from 1% to 46% with monensin, but gram-positive Firmicutes decreased from 93% to 46%. It is noteworthy that EcO157 numbers increased significantly (P<0.01) in Sonneborn medium containing monensin, probably due to monensin-inhibited growth of Vorticella microstoma (P<0.05), a ciliate isolated from wastewater. We conclude that dietary monensin inhibits ciliate protozoa that feed on EcO157. Feed supplements or other methods that enrich these protozoa in cattle manure could be a novel strategy to control the environmental dissemination of EcO157 from dairies to produce production environments. PMID:23349969

  12. Altered protozoan and bacterial communities and survival of Escherichia coli O157:H7 in monensin-treated wastewater from a dairy lagoon.

    PubMed

    Ravva, Subbarao V; Sarreal, Chester Z; Mandrell, Robert E

    2013-01-01

    Surviving predation is a fitness trait of Escherichia coli O157:H7 (EcO157) that provides ample time for the pathogen to be transported from reservoirs (e.g. dairies and feedlots) to farm produce grown in proximity. Ionophore dietary supplements that inhibit rumen protozoa may provide such a selective advantage for EcO157 to proliferate in lagoons as the pathogen is released along with the undigested supplement as manure washings. This study evaluated the fate of an outbreak strain of EcO157, protozoan and bacterial communities in wastewater treated with monensin. Although total protozoa and native bacteria were unaffected by monensin, the time for 90% decrease in EcO157 increased from 0.8 to 5.1 days. 18S and 16S rRNA gene sequencing of wastewater samples revealed that monensin eliminated almost all colpodean and oligohymenophorean ciliates, probably facilitating the extended survival of EcO157. Total protozoan numbers remained high in treated wastewater as monensin enriched 94% of protozoan sequences undetected with untreated wastewater. Monensin stimulated 30-fold increases in Cyrtohymena citrina, a spirotrichean ciliate, and also biflagellate bicosoecids and cercozoans. Sequences of gram-negative Proteobacteria increased from 1% to 46% with monensin, but gram-positive Firmicutes decreased from 93% to 46%. It is noteworthy that EcO157 numbers increased significantly (P<0.01) in Sonneborn medium containing monensin, probably due to monensin-inhibited growth of Vorticella microstoma (P<0.05), a ciliate isolated from wastewater. We conclude that dietary monensin inhibits ciliate protozoa that feed on EcO157. Feed supplements or other methods that enrich these protozoa in cattle manure could be a novel strategy to control the environmental dissemination of EcO157 from dairies to produce production environments.

  13. Tracing organic matter sources and carbon burial in mangrove sediments over the past 160 years

    NASA Astrophysics Data System (ADS)

    Gonneea, Meagan Eagle; Paytan, Adina; Herrera-Silveira, Jorge A.

    2004-10-01

    Mangrove ecosystems may be a source of organic carbon and nutrients to adjacent coastal systems on one hand and provide a sedimentary sink for organic carbon on the other. The balance between these two functions may be sensitive to both natural and anthropogenically induced variability, yet these effects have not been thoroughly evaluated in mangrove ecosystems. We determine organic matter sources and carbon burial rates over the past 160 years in three lagoons on the Yucatan Peninsula, Mexico. Carbon isotopes and C/N elemental ratios are utilized to trace the three sources contributing to sedimentary organic matter, mangroves, seagrasses and phytoplankton, while nitrogen isotopes are used to elucidate potential post-depositional biogeochemical transformations in mangrove lagoon sediments. All three organic matter sources contribute to organic carbon burial. Phytoplankton and mangroves are the dominant sources of organic matter in lagoon bank sediments and seagrasses are a significant source to central lagoon sediments. Organic carbon burial rates are higher at the lagoon fringes, where mangrove vegetation dominates, than in seagrass-dominated mid-lagoon areas. A reduction in mangrove contribution to the sedimentary organic matter pool concurrent with reduced total organic carbon burial rates is observed in the recent past at all three lagoons studied. Natural cycles in sediment organic matter source over the past 160 years are observed in a high-resolution core. These fluctuations correspond to climatic variability in this region, as recorded in deep-sea foraminiferal assemblages. Additional work is required in order to differentiate between recent anthropogenic perturbations and natural variability in organic carbon sources and burial rates within these ecosystems.

  14. On the halophytic nature of mangroves

    USGS Publications Warehouse

    Krauss, Ken W.; Ball, Marilyn C.

    2013-01-01

    Scientists have discussed the halophytic nature of intertidal plants for decades, and have generally suggested that inherent differentiation of an obligate halophyte from a facultative halophyte relates strongly to whether the plant can survive in fresh water, and not much else. In this mini-review, we provide additional insight to support the pervasive notion that mangroves as a group are truly facultative halophytes, and thus add discourse to the alternate view that mangroves have an obligate salinity requirement. Indeed, growth and physiological optima are realized at moderate salinity concentrations in mangroves, but we maintain the notion that current evidence suggests that survival is not dependent upon a physiological requirement for salt.

  15. Mangroves Response to Climate Change: A Review of Recent Findings on Mangrove Extension and Distribution.

    PubMed

    Godoy, Mario D P; de Lacerda, Luiz D

    2015-01-01

    Mangroves function as a natural coastline protection for erosion and inundation, providing important environmental services. Due to their geographical distribution at the continent-ocean interface, the mangrove habitat may suffer heavy impacts from global climate change, maximized by local human activities occurring in a given coastal region. This review analyzed the literature published over the last 25 years, on the documented response of mangroves to environmental change caused by global climate change, taking into consideration 104 case studies and predictive modeling, worldwide. Most studies appeared after the year 2000, as a response to the 1997 IPCC report. Although many reports showed that the world's mangrove area is decreasing due to direct anthropogenic pressure, several others, however, showed that in a variety of habitats mangroves are expanding as a response to global climate change. Worldwide, pole ward migration is extending the latitudinal limits of mangroves due to warmer winters and decreasing the frequency of extreme low temperatures, whereas in low-lying coastal plains, mangroves are migrating landward due to sea level rise, as demonstrated for the NE Brazilian coast. Taking into consideration climate change alone, mangroves in most areas will display a positive response. In some areas however, such as low-lying oceanic islands, such as in the Pacific and the Caribbean, and constrained coastlines, such as the SE Brazilian coast, mangroves will most probably not survive.

  16. Effects of hydrology on red mangrove recruits

    USGS Publications Warehouse

    Doyle, Thomas W.

    2003-01-01

    Coastal wetlands along the Gulf of Mexico have been experiencing significant shifts in hydrology and salinity levels over the past century as a result of changes in sea level and freshwater drainage patterns. Local land management in coastal zones has also impacted the hydrologic regimes of salt marshes and mangrove areas. Parks and refuges in south Florida that contain mangrove forests have, in some cases, been ditched or impounded to control mosquito outbreaks and to foster wildlife use. And while mangroves dominate the subtropical coastlines of Florida and thrive in saltwater environments, little is known about how they respond to changes in hydrology under managed or variable tidal conditions. USGS researchers designed a study to evaluate the basic hydrological requirements of mangroves so that their health and survival may be more effectively managed in controlled impoundments and restored wetlands. Mangroves are commonly found in the intertidal zone (between low and high tides) in a rather broad spectrum of hydrologic settings. Because they thrive at the interface of land and sea, mangroves are subject to changes in freshwater flow (flow rate, nutrients, pollutants) and to marine influences (sea-level rise, salinity). Salinity has long been recognized as a controlling factor that determines the health and distribution of mangrove forests. Field and experimental observations indicate that most mangrove species achieve their highest growth potential under brackish conditions (modest salinity) between 10 and 20 parts per thousand (ppt). Yet, if provided with available propagules, successful regeneration, and limited competition from other plants, then mangroves can survive and thrive in freshwater systems as well. Because little is known about the growthand survival patterns of mangrove species relative to changing hydrology, USGS scientists conducted greenhouse and field experiments to determine how flooded or drained patterns of hydrology would influence

  17. A review of mangrove and coastal ecosystems in West Africa and their possible relationships

    NASA Astrophysics Data System (ADS)

    John, D. M.; Lawson, G. W.

    1990-11-01

    Mangrove forest, which in West Africa covers an area of over 27 000 km 2 of deltas, estuaries and lagoons, is intimately linked to the offshore coastal ecosystem. Regularly influenced and disturbed by seasonal freshwater and diurnal tidal flooding, it exhibits features of an immature ecosystem, namely low species diversity and high productivity. The excess organic production is exploited by many marine species especially fishes and crustaceans that enter the mangrove environment as juveniles and return to the sea as adults for reproductive purposes. The beneficial effects on marine fisheries of this net energy outflow are at risk from anthropogenic influences causing pollution or destruction of the mangrove ecosystem. Intense interdisciplinary work on this problem is in progress on the lagoons of the Ivory Coast but further research on other parts of the West African mangrove ecosystem, especially on the Niger delta, needs to be undertaken to provide the scientific basis for the proper management of this valuable natural resource.

  18. Modelling drivers of mangrove propagule dispersal and restoration of abandoned shrimp farms

    NASA Astrophysics Data System (ADS)

    Di Nitto, D.; Erftemeijer, P. L. A.; van Beek, J. K. L.; Dahdouh-Guebas, F.; Higazi, L.; Quisthoudt, K.; Jayatissa, L. P.; Koedam, N.

    2013-07-01

    Propagule dispersal of four mangrove species Rhizophora mucronata, R. apiculata, Ceriops tagal and Avicennia officinalis in the Pambala-Chilaw Lagoon Complex (Sri Lanka) was studied by combining a hydrodynamic model with species-specific knowledge on propagule dispersal behaviour. Propagule transport was simulated using a finite-volume advection-diffusion model to investigate the effect of dispersal vectors (tidal flow, freshwater discharge and wind), trapping agents (retention by vegetation) and seed characteristics (buoyancy) on propagule dispersal patterns. Sensitivity analysis showed that smaller propagules, like the oval-shaped propagules of Avicennia officinalis, dispersed over larger distances and were most sensitive to changing values of retention by mangrove vegetation compared to larger, torpedo-shaped propagules of Rhizophora spp. and C. tagal. Directional propagule dispersal in this semi-enclosed lagoon with a small tidal range was strongly concentrated towards the edges of the lagoon and channels. Short distance dispersal appeared to be the main dispersal strategy for all four studied species, with most of the propagules being retained within the vegetation. Only a small proportion (max. 5%) of propagules left the lagoon through a channel connecting the lagoon with the open sea. Wind significantly influenced dispersal distance and direction once propagules entered the lagoon or adjacent channels. Implications of these findings for mangrove restoration were tested by simulating partial removal in the model of dikes around abandoned shrimp ponds to restore tidal hydrology and facilitate natural recolonisation by mangroves. The specific location of dike removal, (with respect to the vicinity of mangroves and independently suitable hydrodynamic flows), was found to significantly affect the resultant quantities and species of inflowing propagules and hence the potential effectiveness of natural regeneration. These results demonstrate the value of propagule

  19. Modelling drivers of mangrove propagule dispersal and restoration of abandoned shrimp farms

    NASA Astrophysics Data System (ADS)

    Di Nitto, D.; Erftemeijer, P. L. A.; van Beek, J. K. L.; Dahdouh-Guebas, F.; Higazi, L.; Quisthoudt, K.; Jayatissa, L. P.; Koedam, N.

    2013-01-01

    Propagule dispersal of four mangrove species Rhizophora mucronata, R. apiculata, Ceriops tagal and Avicennia officinalis in the Pambala-Chilaw Lagoon Complex (Sri Lanka) was studied by combining a hydrodynamic model with species-specific knowledge on propagule dispersal behaviour. Propagule transport was simulated using a finite-volume advection-diffusion model to investigate the effect of dispersal vectors (tidal flow, freshwater discharge and wind), trapping agents (retention by vegetation) and seed characteristics (buoyancy) on propagule dispersal patterns. Sensitivity analysis showed that smaller propagules, like the oval-shaped propagules of Avicennia officinalis, dispersed over larger distances and were most sensitive to changing values of retention by mangrove vegetation compared to larger, torpedo-shaped propagules of Rhizophora spp. and C. tagal. Directional propagule dispersal in this semi-enclosed lagoon with a small tidal range was strongly concentrated towards the edges of the lagoon and channels. Short distance dispersal appeared to be the main dispersal strategy for all four studied species, with most of the propagules being retained within the vegetation. Only a small proportion (max. 5%) of propagules left the lagoon through a channel connecting the lagoon with the open sea. Wind significantly influenced dispersal distance and direction once propagules entered the lagoon or adjacent channels. Implications of these findings for mangrove restoration were tested by simulating partial removal in the model of dikes around abandoned shrimp ponds to restore tidal hydrology and facilitate natural recolonisation by mangroves. The specific location of dike removal, (with respect to the vicinity of mangroves and independently suitable hydrodynamic flows), was found to significantly affect the resultant quantities and species of inflowing of propagules and hence the potential effectiveness of natural regeneration. These results demonstrate the value of

  20. Bacterial N2-fixation in mangrove ecosystems: insights from a diazotroph-mangrove interaction.

    PubMed

    Alfaro-Espinoza, Gabriela; Ullrich, Matthias S

    2015-01-01

    Mangrove forests are highly productive ecosystems but represent low nutrient environments. Nitrogen availability is one of the main factors limiting mangrove growth. Diazotrophs have been identified as key organisms that provide nitrogen to these environments. N2-fixation by such organisms was found to be higher in the mangrove roots than in surrounding rhizosphere. Moreover, previous studies showed that mangroves grew better in the presence of N2-fixers indicating a potentially mutualistic relationship. However, the molecular signals and mechanisms that govern these interactions are still poorly understood. Here we present novel insights in the interaction of a diazotroph with a mangrove species to improve our understanding of the molecular and ecophysiological relationship between these two organisms under controlled conditions. Our results showed that Marinobacterium mangrovicola is a versatile organism capable of competing with other organisms to survive for long periods in mangrove soils. N2-fixation by this bacterium was up-regulated in the presence of mangrove roots, indicating a possible beneficial interaction. The increase in N2-fixation was limited to cells of the exponential growth phase suggesting that N2-fixation differs over the bacterial growth cycle. Bacterial transformants harboring a transcriptional nifH::gusA fusion showed that M. mangrovicola successfully colonized mangrove roots and simultaneously conducted N2-fixation. The colonization process was stimulated by the lack of an external carbon source suggesting a possible mutualistic relationship. M. mangrovicola represents an interesting genetically accessible diazotroph, which colonize mangrove roots and exhibit higher N2-fixation in the presence of mangrove roots. Consequently, we propose this microorganism as a tool to study molecular interactions between N2-fixers and mangrove plants and to better understand how changes in the environment could impact these important and relatively unknown

  1. Bacterial N2-fixation in mangrove ecosystems: insights from a diazotroph–mangrove interaction

    PubMed Central

    Alfaro-Espinoza, Gabriela; Ullrich, Matthias S.

    2015-01-01

    Mangrove forests are highly productive ecosystems but represent low nutrient environments. Nitrogen availability is one of the main factors limiting mangrove growth. Diazotrophs have been identified as key organisms that provide nitrogen to these environments. N2-fixation by such organisms was found to be higher in the mangrove roots than in surrounding rhizosphere. Moreover, previous studies showed that mangroves grew better in the presence of N2-fixers indicating a potentially mutualistic relationship. However, the molecular signals and mechanisms that govern these interactions are still poorly understood. Here we present novel insights in the interaction of a diazotroph with a mangrove species to improve our understanding of the molecular and ecophysiological relationship between these two organisms under controlled conditions. Our results showed that Marinobacterium mangrovicola is a versatile organism capable of competing with other organisms to survive for long periods in mangrove soils. N2-fixation by this bacterium was up-regulated in the presence of mangrove roots, indicating a possible beneficial interaction. The increase in N2-fixation was limited to cells of the exponential growth phase suggesting that N2-fixation differs over the bacterial growth cycle. Bacterial transformants harboring a transcriptional nifH::gusA fusion showed that M. mangrovicola successfully colonized mangrove roots and simultaneously conducted N2-fixation. The colonization process was stimulated by the lack of an external carbon source suggesting a possible mutualistic relationship. M. mangrovicola represents an interesting genetically accessible diazotroph, which colonize mangrove roots and exhibit higher N2-fixation in the presence of mangrove roots. Consequently, we propose this microorganism as a tool to study molecular interactions between N2-fixers and mangrove plants and to better understand how changes in the environment could impact these important and relatively unknown

  2. Methane Emissions from Tropical Coastal Lagoons, Yucatan, Mexico

    NASA Astrophysics Data System (ADS)

    Young, M.; Paytan, A.; Herrera-Silveira, J.

    2003-12-01

    Tropical and sub-tropical wetlands are thought to be the dominant natural source of methane to the atmosphere, and the majority of tropical methane flux research has been carried out in freshwater environments. In order to obtain better estimates of methane emissions from tropical coastal environments, we are currently conducting a multi-year study of methane cycling and flux in three tropical coastal lagoons and associated mangrove ecosystems located on the Yucatan Peninsula in Mexico. Previous studies have shown that methane emissions from tropical coastal ecosystems are widely variable, and that these emissions can be quite high despite the presence of moderate to marine salinities. We measured surface water methane concentrations in two lagoons (Celestun and Chelem) during different seasons, as well as in a third, heavily polluted lagoon (Terminos), during the rainy season. Celestun lagoon has a distinct year-round salinity gradient (7-35 ppt) due to groundwater input, Terminos lagoon ranges from fresh water at the river entrances to marine in most of the lagoon area, and Chelem has a salinity range from marine to slightly hyper-saline (30-40 ppt). Diffusive methane flux to the atmosphere was calculated from surface water methane concentrations, using both sample-specific and average area wind speed measurements. Additionally, flux chambers were used to measure methane emissions from each of the lagoons during the rainy season. Calculated diffusive fluxes ranged from less than 1 mg CH4/m2/day up to 100 mg CH4/m2/day in all three lagoons, with the highest fluxes occurring in both areas of lower salinity and areas with known waste water discharge. However, measurements of bubble flux made using flux chambers were between 20 and 150 times greater than the diffusive flux calculated for the same locations. During the course of this study, it appears that the most significant bubble flux occurs in these lagoons during the rainy season. Observations and flux chamber

  3. Mangrove microclimates alter seedling dynamics at the range edge.

    PubMed

    Devaney, John L; Lehmann, Michael; Feller, Ilka C; Parker, John D

    2017-08-05

    Recent climate warming has led to asynchronous species migrations, with major consequences for ecosystems worldwide. In woody communities, localized microclimates have the potential to create feedback mechanisms that can alter the rate of species range shifts attributed to macroclimate drivers alone. Mangrove encroachment into saltmarsh in many areas is driven by a reduction in freeze events, and this encroachment can further modify local climate, but the subsequent impacts on mangrove seedling dynamics are unknown. We monitored microclimate conditions beneath mangrove canopies and adjacent open saltmarsh at a freeze-sensitive mangrove-saltmarsh ecotone and assessed survival of experimentally transplanted mangrove seedlings. Mangrove canopies buffered night time cooling during the winter, leading to interspecific differences in freeze damage on mangrove seedlings. However, mangrove canopies also altered biotic interactions. Herbivore damage was higher under canopies, leading to greater mangrove seedling mortality beneath canopies relative to saltmarsh. While warming-induced expansion of mangroves can lead to positive microclimate feedbacks, simultaneous fluctuations in biotic drivers can also alter seedling dynamics. Thus, climate change can drive divergent feedback mechanisms through both abiotic and biotic channels, highlighting the importance of vegetation-microclimate interactions as important moderators of climate driven range shifts. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  4. Phytoplankton variation and its relation to nutrients and allochthonous organic matter in a coastal lagoon on the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Aké-Castillo, José A.; Vázquez, Gabriela

    2008-07-01

    In tropical and subtropical zones, coastal lagoons are surrounded by mangrove communities which are a source of high quantity organic matter that enters the aquatic system through litter fall. This organic matter decomposes, becoming a source of nutrients and other substances such as tannins, fulvic acids and humic acids that may affect the composition and productivity of phytoplankton communities. Sontecomapan is a coastal lagoon located in the southern Gulf of Mexico, which receives abundant litter fall from mangrove. To study the phytoplankton composition and its variation in this lagoon from October 2002 to October 2003, we evaluated the concentrations of dissolved folin phenol active substances (FPAS) as a measure of plant organic matter, salinity, temperature, pH, O 2, N-NH 4+, N-NO 3-, P-PO 43-, Si-SiO 2, and phytoplanktonic cell density in different mangrove influence zones including the three main rivers that feed the lagoon. Nutrients concentrations depended on freshwater from rivers, however these varied seasonally. Concentrations of P-PO 43-, N-NH 4+ and FPAS were the highest in the dry season, when maximum mangrove litter fall is reported. Variation of these nutrients seemed to depend on the internal biogeochemical processes of the lagoon. Blooms of diatoms ( Skeletonema spp., Cyclotella spp. and Chaetoceros holsaticus) and dinoflagellates ( Peridinium aff. quinquecorne, Prorocentrum cordatum) occurred seasonally and in the different mangrove influence zones. The high cell densities in these zones and the occurrence of certain species and its ordination along gradient of FPAS in a canonical correspondence analysis, suggest that plant organic matter (i.e. mangrove influence) may contribute to phytoplankton dynamics in Sontecomapan lagoon.

  5. Nutrient fluxes in a semi-arid microtidal mangrove wetland in the Gulf of California

    NASA Astrophysics Data System (ADS)

    Sánchez-Carrillo, S.; Sánchez-Andrés, R.; Alatorre, L. C.; Angeler, D. G.; Álvarez-Cobelas, M.; Arreola-Lizárraga, J. A.

    2009-05-01

    Nutrient (C, N and P) fluxes were monitored in a microtidal semi-arid mangrove system, which links a semi-enclosed shallow coastal lagoon with the Gulf of California. We assessed the role of the mangrove ecosystem as a nutrient sink/source and determined how mangrove litterfall rates, tidal regime and climate factors influence these fluxes. Despite high seasonal differences in DOC, POC, N-NO 3- and TP levels, nutrient concentrations were only marginally influenced by either hydrological variables or the concentration of these fractions in the adjacent lagoon. The carbon budget appeared to be balanced throughout the study. Retention rates in the mangrove system were related to litterfall rates. Export of DIN was observed mainly in the wet season due to the low nitrogen assimilation efficiency of the system. Import of organic nitrogen was related to the high retention efficiency of particulate organic nitrogen. Phosphorus fractions were imported and retained in the mangrove supporting previous findings that mangroves are phosphorus sinks. Finally, through a simple meta-analysis we tested the quantitative importance of main variables (tidal flow, tidal elevation, tidal range, rainfall, mangrove catchment area, litterfall) controlling mangrove nutrient dynamics. Although results suggest that generalizations can be made about factors regulating nutrient export from mangroves, the lack of statistical significance highlights the relative importance of the local environment for the magnitude of nutrient exchange in mangroves. Future research should focus on finding mechanistic models to explain these general patterns, taking into account the main biogeochemical processes and their roles in coastal ecosystem ecology.

  6. Sedimentation and belowground carbon accumulation rates in mangrove forests that differ in diversity and land use: a tale of two mangroves

    Treesearch

    Richard A. MacKenzie; Patra B. Foulk; J. Val Klump; Kimberly Weckerly; Joko Purbospito; Daniel Murdiyarso; Daniel C. Donato; Vien Ngoc Nam

    2016-01-01

    Increased sea level is the climate change effect expected to have the greatest impact on mangrove forest survival. Mangroves have survived extreme fluctuations in sea level in the past through sedimentation and belowground carbon (C) accumulation, yet it is unclear what factors may influence these two parameters. We measured sedimentation, vertical accretion, and...

  7. Toxicity of contaminants in lagoons and pannes of the Indiana Dunes National Lakeshore

    SciTech Connect

    Gillespie, R.; Speelman, J.; Stewart, P.M.

    1995-12-31

    Contaminants in water and sediments of lagoons and pannes were 2--90 times greater at sites adjacent to slag and coal piles than those at reference sites. One site (Lagoon-US5) had sediments with very high concentrations of toxic organics (e.g. naphthalene, phenanthrene, dibenzofuran). Although analyses indicated a gradient of contaminant concentration with distance from their sources, toxicity assays were somewhat equivocal. With the exception of less reproduction in Ceriodaphnia at one lagoon site (US3 = 0.55 of reference), survival of fathead minnows and reproduction in Ceriodaphnia in lagoon and panne waters varied independently of the contaminant concentration. In fact, there was better Ceriodaphnia reproduction in water from two contaminated sites (Lagoon-US5, Panne-WP1) than in water from reference sites. Fathead minnow survival, Ceriodaphnia survival, Ceriodaphnia reproduction, amphipod survival, and amphipod growth varied among sites in toxicity assays with sediments, 100% mortality of fatheads at Lagoon-US5, 100% mortality of Ceriodaphnia at Lagoon-US3, and less survival of fathead minnows at Lagoon-US3 indicate possible toxicity from contaminants in sediments at these sites. Of all organisms and end-points tested, Ceriodaphnia survival seemed to be most closely associated with concentrations of contaminants in lagoon water and sediments. Amphipod survival also varied with contaminants in sediments, however, survival in sediments of contaminated sites ranged only from 0.90--0.93 of reference sites. Although the results are not consistent among organisms, toxicity assays indicate that sediments from the lagoon site with the highest contaminants (Lagoon-US5) and possibly those from another contaminated lagoon site (Lagoon-US3) could be toxic to aquatic organisms. Water and sediments from contaminated panne sites do not appear to be toxic to aquatic test organisms.

  8. Sedimentation in mangroves and coral reefs in a wet tropical island, Pohnpei, Micronesia

    NASA Astrophysics Data System (ADS)

    Victor, Steven; Neth, Leinson; Golbuu, Yimnang; Wolanski, Eric; Richmond, Robert H.

    2006-02-01

    A six-month-long study was conducted of the fate of turbid river plumes from the Enipein watershed in Pohnpei, Federated States of Micronesia. Pohnpei is one of the wettest places on earth, with a mean annual rainfall exceeding 4 m in the lowlands and 8 m in the highlands. The river waters were clear of sediment except after major storms with rainfall exceeding 5 cm day -1. Following a storm, the river plume spread in the mangrove fringed estuary and in the coral reef lagoon. The waters were highly stratified in temperature, salinity, and suspended sediment concentration. The brackish water was flushed out in four days, while the suspended sediment all settled out in the estuary, in the mangroves, and in the lagoon including on the coral reefs, in less than one day. The mean rate of sedimentation exceeded 35 mg cm -2 d -1 both over the mangroves and on the adjacent coral reefs. While this leads to no detrimental effects on the mangroves, sediment smothers corals and leads to substantial coral mortality in the lagoon. The mud is not flushed out from the lagoon because there are no strong currents from waves or tides. This high sedimentation rate is attributable to poor farming and land-use practices on the upland areas.

  9. Lagoons and Oxidation Ponds.

    ERIC Educational Resources Information Center

    O'Brien, W. J.

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. This review covers lagoons and oxidation ponds, and it includes some areas such as improving the effluents from ponds, stabilization ponds, aerated lagoons, and oxidation ditches. A list of 36 references is also presented. (HM)

  10. Lagoons and Oxidation Ponds.

    ERIC Educational Resources Information Center

    O'Brien, W. J.

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. This review covers lagoons and oxidation ponds, and it includes some areas such as improving the effluents from ponds, stabilization ponds, aerated lagoons, and oxidation ditches. A list of 36 references is also presented. (HM)

  11. Mangroves, Coral, and the Search for a Paleotsunami Deposit Along the Andaman Coast of Thailand.

    NASA Astrophysics Data System (ADS)

    Rhodes, B.; Jankaew, K.; Kirby, M.

    2007-05-01

    Finding a preserved paleotsunami deposit along Thailand's Andaman coast has proven to be a major challenge. The coastline is tectonically stable precluding the preservation of tsunami deposits due to sudden sea level changes. Much of the coast is fringed by wide beach plains that have been thoroughly disturbed during a long history of placer tin mining. In the rare undisturbed areas, distinguishing potential paleotsunami sand layers from interlayered beach deposits is frustratingly difficult. In the central part of Phangnga Province, several large areas of mangrove-fringed coastal lagoons formed during Holocene sea level rise. The fine sand, mud and peat that accumulated in these quiet lagoons provide a suitably contrasting host for coarser tsunami deposits. The December 2004 tsunami entered these tidal channels destroying swaths of mangroves up to 200 m wide. Satellite images showing the patterns of destroyed mangroves suggest that the energy of the tsunami varied greatly along the lagoons' shores. Sampling in shallow trenches along transects across these swaths suggests that the sand layer marking this tsunami is thickest where the mangroves are destroyed, and thins rapidly landward into the standing mangroves. Intense bioturbation within the mangroves is already mixing the sand with the underlying peat and mud. Thus, deposition of any paleotsunami sand layer would be as discontinuous lenses along the paleoshoreline, and mixing with the enclosing sediment may mask it. Perhaps the best opportunity for discovering a paleotsunami deposit is to locate an unusually coarse deposit that could endure bioturbation. We found one such deposit in the Thap Lamu lagoon where the 2004 tsunami deposited a litter of angular coral-gravel blanketing an unusually large zone of destroyed mangroves. Cores collected along two transects across this zone penetrated a similar layer of coral gravel at 1-2 m depth. This coral-gravel layer thins landward, and cross cuts a facies boundary

  12. Factors Controlling the Morphodynamics of a Tropical Coastal Lagoon.

    NASA Astrophysics Data System (ADS)

    Enriquez, C.; Marino-Tapia, I.

    2016-02-01

    Celestun is a large (22 km) and elongated (north-south axis) tropical coastal lagoon known for its beauty and biodiversity, but its morphology has been artificially altered by an embankment road built to provide access to the coastal town. This road divided the lagoon by the middle nearly blocking the communication and heavily altering the hydrodynamics. Since then, the head has a restricted circulation (hence higher residence time) and accretion processes have modified the flows affecting the water quality and the tidal flooding towards the wetland and mangrove regions surrounding the lagoon. In this study a morphodynamic process-based numerical model (DELFT3D) is used to investigate the hydro and morphodynamics of Celestun resulting from various meteorological and oceanographic forcings and under different scenarios of anthropogenic alterations (i.e. with and without the road). The coastal lagoon receives important submarine groundwater discharges and therefore the influence of density gradients in the system dynamics is also studied. Results show that the tides control the instantaneous hydrodynamic characteristics but the continental water discharges through SGDs and their variations dominate the morphodynamics in relation to the channel development and evolution. The embankment road restricts the flow to the upper half of the lagoon, minimizing the water circulation at the head, and modifies the circulation patterns creating a large region of accretion in the south near the road.

  13. Effects of increased summer flooding on nitrogen dynamics in impounded mangroves.

    PubMed

    Verhoeven, Jos T A; Laanbroek, Hendrikus J; Rains, Mark C; Whigham, Dennis F

    2014-06-15

    Mangroves are important for coastal protection, carbon sequestration and habitat provision for plants and animals in the tropics and subtropics. Mangroves are threatened by habitat destruction and sea level rise, but management activities such as impounding for mosquito control can also have negative effects. We studied the effects of Rotational Impoundment Management (RIM) on nitrogen dynamics in impoundments dominated by three types of Black mangrove (Avicennia germinans) stands along the Indian River Lagoon (Florida). RIM, designed for noxious insect control, involves pumping estuarine water into impoundments in this area during spring and summer to raise water levels by 30 cm. We compared aspects of the nitrogen cycle before and after the start of the RIM and measured the same variables in an impoundment without RIM management. RIM led to the accumulation of ammonium in the substrate which coincided with a lowering of nitrification rates and decreased denitrification rates. Salt pan habitats dominated by dwarf mangroves became less saline following RIM initiation. Shoot growth of mangroves increased in response to higher nitrogen availability and lower pore water salinity. Mangrove responses were greatest in areas with dwarf and sparse mangrove cover. Overall, RIM resulted in lower nitrification and denitrification leading to lower nitrogen losses and increased Black mangrove growth, all benefits of RIM beyond those associated with noxious insect control.

  14. High heterogeneity in soil composition and quality in different mangrove forests of Venezuela.

    PubMed

    Otero, X L; Méndez, A; Nóbrega, G N; Ferreira, T O; Meléndez, W; Macías, F

    2017-09-18

    Mangrove forests play an important role in biogeochemical cycles of metals, nutrients, and C in coastal ecosystems. However, these functions could be strongly affected by the mangrove soil degradation. In this study, we performed an intensive sampling characterizing mangrove soils under different types of environment (lagoon/gulf) and vegetation (Rhizophora/Avicennia/dead mangrove) in the Venezuelan coast. To better understand the spatial heterogeneity of the composition and characteristics of the soils, a wide range of the soil attributes were analyzed. In general, the soils were anoxic (Eh < 200 mV), with a neutral pH and low concentration in toxic metals; nevertheless, they varied widely in the soil and its quality-defining parameters (e.g., clay contents, total organic carbon, Fe, Al, toxic trace metals). It is noteworthy that the mangroves presented a low FePyrite content due to a limitation in the Fe oxyhydroxide contents, especially in soils with higher organic C content (TOC > 15%). Finally, the dead mangrove showed significantly lower amounts of TOC and fibers (in comparison to the well-preserved mangrove forest), which indicates that the C pools in mangrove soils are highly sensitive also to natural impact, such as ENSO.

  15. What makes mangroves attractive to fish? Use of artificial units to test the influence of water depth, cross-shelf location, and presence of root structure

    NASA Astrophysics Data System (ADS)

    Nagelkerken, I.; Faunce, C. H.

    2008-09-01

    Mangroves are an attractive fish habitat because they provide shelter and food for juvenile fishes. However, because mangroves are almost always located in shallow water and in sheltered (i.e., lagoonal, estuarine or bay) environments, the degree to which the latter two factors contribute to the attractiveness of mangrove prop-roots as a fish habitat is unknown. Artificial Mangrove Units (AMUs) were placed at multiple depths and along a gradient from an embayment to, and including, the coral reef. Total fish density and species richness in AMUs placed in the embayment was lower at 1 m depth than at 2 and 3 m depth, suggesting that shallow water is not a prerequisite for the attractiveness of mangrove prop-roots as a fish habitat. Total fish density and species richness were equal or greater in AMUs on the coral reef than in the embayment, suggesting that placement of mangroves in a sheltered lagoonal environment is not solely responsible for the attractiveness of mangrove prop-roots either. After 3 weeks, removal of AMUs did not have a negative effect on total fish density or species richness. However, within the embayment AMU removal resulted in the complete collapse of the assemblage component comprised of species that use mangroves as juvenile habitats, highlighting the need for a species-based approach towards assessing the benefits provided by the presence of mangrove root structure for fishes.

  16. Brazil The Duck Lagoon

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Multi-angle Imaging SpectroRadiometer (MISR) image of Brazil covers an area of about 298 kilometers x 358 kilometers, and was captured by the instrument's vertical-viewing (nadir) camera on December 27, 2001. The 'Lagoa dos Patos', in the Brazilian state of Rio Grande do Sul, translates to 'the Duck Lagoon'. It was named by 16th century Jesuit settlers, who asked the King of Spain to grant them title to the lagoon so that they could breed ducks. The King consented, but revoked his edict when he discovered that the 'duck-pond' (measuring about 14,000 square kilometers) was one of the largest lagoonal systems in the world. Note the sediment plume emanating from the southern end of the lagoon. Sailors in the 16th century imagined this outlet to be the mouth of a large river. Early Portuguese explorers mistook the entrance to the lagoon for the mouth of a great river and called it the Rio Grande. A series of wave-like points and curls form 'cusps' on the inner shores of the lagoon. The lagoon's characteristics change with short-term tide-induced cyclic perturbations, and with longer term large scale meteorological conditions. The distinctive wavelike 'cusps' along the inner shores result from the circulation, erosion and accumulation of sediments driven by wind and tidal action. The El Nino Southern Oscillation (ENSO) circulation affects precipitation amount and continental runoff, thereby changing the contents of the lagoon waters. High rainfall and increased freshwater discharge during El Nino events correspond with elevated dissolved nutrient concentrations and increased phytoplankton growth. La Nina years are dry and the associated low rainfall reduces the freshwater recharge to the lagoon, causing an increase in salinity. Occasional blooms of toxic cyanobacteria (Microcystis aeruginosa), have been registered in the lagoon when nutrient concentrations are elevated. A number of reeds and grasses are important to the lagoon estuary, including widgeon grass

  17. Brazil The Duck Lagoon

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Multi-angle Imaging SpectroRadiometer (MISR) image of Brazil covers an area of about 298 kilometers x 358 kilometers, and was captured by the instrument's vertical-viewing (nadir) camera on December 27, 2001. The 'Lagoa dos Patos', in the Brazilian state of Rio Grande do Sul, translates to 'the Duck Lagoon'. It was named by 16th century Jesuit settlers, who asked the King of Spain to grant them title to the lagoon so that they could breed ducks. The King consented, but revoked his edict when he discovered that the 'duck-pond' (measuring about 14,000 square kilometers) was one of the largest lagoonal systems in the world. Note the sediment plume emanating from the southern end of the lagoon. Sailors in the 16th century imagined this outlet to be the mouth of a large river. Early Portuguese explorers mistook the entrance to the lagoon for the mouth of a great river and called it the Rio Grande. A series of wave-like points and curls form 'cusps' on the inner shores of the lagoon. The lagoon's characteristics change with short-term tide-induced cyclic perturbations, and with longer term large scale meteorological conditions. The distinctive wavelike 'cusps' along the inner shores result from the circulation, erosion and accumulation of sediments driven by wind and tidal action. The El Nino Southern Oscillation (ENSO) circulation affects precipitation amount and continental runoff, thereby changing the contents of the lagoon waters. High rainfall and increased freshwater discharge during El Nino events correspond with elevated dissolved nutrient concentrations and increased phytoplankton growth. La Nina years are dry and the associated low rainfall reduces the freshwater recharge to the lagoon, causing an increase in salinity. Occasional blooms of toxic cyanobacteria (Microcystis aeruginosa), have been registered in the lagoon when nutrient concentrations are elevated. A number of reeds and grasses are important to the lagoon estuary, including widgeon grass

  18. Trace metal geochemistry in mangrove sediments and their transfer to mangrove plants (New Caledonia).

    PubMed

    Marchand, C; Fernandez, J-M; Moreton, B

    2016-08-15

    Because of their physico-chemical inherent properties, mangrove sediments may act as a sink for pollutants coming from catchments. The main objective of this study was to assess the distribution of some trace metals in the tissues of various mangrove plants developing downstream highly weathered ferralsols, taking into account metals partitioning in the sediment. In New Caledonia, mangroves act as a buffer between open-cast mines and the world's largest lagoon. As a result of the erosion of lateritic soils, Ni and Fe concentrations in the sediment were substantially higher than the world average. Whatever the mangrove stand and despite low bioaccumulation and translocations factors, Fe and Ni were also the most abundant metals in the different plant tissues. This low bioaccumulation may be explained by: i) the low availability of metals, which were mainly present in the form of oxides or sulfur minerals, and ii) the root systems acting as barriers towards the transfer of metals to the plant. Conversely, Cu and Zn metals had a greater mobility in the plant, and were characterized by high bioconcentration and translocation factors compared to the other metals. Cu and Zn were also more mobile in the sediment as a result of their association with organic matter. Whatever the metal, a strong decrease of trace metal stock was observed from the landside to the seaside of the mangrove, probably as a result of the increased reactivity of the sediment due to OM enrichment. This reactivity lead to higher dissolution of bearing phases, and thus to the export of dissolved trace metals trough the tidal action. Cu and Zn were the less concerned by the phenomenon probably as a result of higher plant uptake and their restitution to the sediment with litter fall in stands where tidal flushing is limited.

  19. Ontogenetic patterns of concentration indicate lagoon nurseries are essential to common grunts stocks in a Puerto Rican bay

    NASA Astrophysics Data System (ADS)

    Burke, John Selden; Kenworthy, W. Judson; Wood, Lisa L.

    2009-03-01

    Estimates of abundance and size of three commercially exploited grunt species indicate ontogenetic changes in habitat utilization concentrate their juveniles within the lagoon of the Bay of La Parguera, Puerto Rico. Eleven biotopes, defined by four benthic structures (reef, mangrove, vegetation beds and unconsolidated sediments) and three geographic zones (inner lagoon, outer lagoon and bank shelf) were sampled randomly by visual surveys. French, bluestriped and white grunt ( Haemulon flavolineatum, Haemulon sciurus and Haemulon plumeri) were common in the bay and appeared to exhibit similar life history patterns of cross-shelf migration and habitat selection. Recently settled grunts were dispersed over vegetated and unconsolidated soft-bottom sediments of the bay. The juvenile stage occurred in highest densities in shallow lagoon biotopes among the submerged prop-roots of mangrove stands and on inshore reefs. Length data indicates that grunts migrate offshore to adult habitat via increasingly deep reefs. Indices of biotope nursery function based on standing stock estimates of juveniles identified three biotopes, all within the inner lagoon as essential habitat for juveniles of 5-10 cm length interval. This concentration of juveniles within biotopes of the lagoon could represent a bottleneck to recruitment for grunt stocks. Evidence that quantity and quality of lagoon nurseries may limit recruitment indicates that these areas represent a key component of a marine protected area designed to restore fisheries within the bay.

  20. Brazil: Duck Lagoon

    Atmospheric Science Data Center

    2013-04-18

    ... in the lagoon during spring and summer. Although the lowland tapir (Tapirus terrestris) is found in some parts of Rio Grande do Sul, the Baird's tapir (Tapirus bairdii), is not distributed within the image area (it is ...

  1. Lockport Sewage Lagoon.

    ERIC Educational Resources Information Center

    Perry, John

    1995-01-01

    Describes a student initiated stewardship project that resulted in the transformation of a sewage lagoon near the school into a place to study nature. Contains a list of 20 things that discourage a successful stewardship project. (LZ)

  2. Lockport Sewage Lagoon.

    ERIC Educational Resources Information Center

    Perry, John

    1995-01-01

    Describes a student initiated stewardship project that resulted in the transformation of a sewage lagoon near the school into a place to study nature. Contains a list of 20 things that discourage a successful stewardship project. (LZ)

  3. Comparative oceanography of coastal lagoons

    NASA Technical Reports Server (NTRS)

    Kjerfve, Bjorn

    1986-01-01

    The hypothesis that physical lagoon characteristics and variability depend on the channel connecting the lagoon to the adjacent coastal ocean is evaluated. The geographical, hydrological, and oceanographic characteristics of 10 lagoon systems are described and analyzed; these oceanographic features are utilized to classify the lagoon systems. Choked lagoons (Laguna Joyuda, Coorong, Lake St.Lucia, Gippsland Lakes, Lake Songkla/Thale Luang/Thale Noi, and Lagoa dos Patos) are prevalent on coasts with high wave energy and low tidal range; restricted lagoons (Lake Pontchartrain and Laguna de Terminos) are located on low/medium wave energy coasts with a low tidal range; and leaky lagoons (Mississippi Sound and Belize Lagoon/Chetumal Bay) are connected to the ocean by wide tidal passes that transmit oceanic effects into the lagoon with a minimum of resistance. The data support the hypothesis that the nature of the connecting channel controls system functions.

  4. Spatial variability of primary organic sources regulates ichthyofauna distribution despite seasonal influence in Terminos lagoon and continental shelf of Campeche, Mexico

    NASA Astrophysics Data System (ADS)

    Romo Rios, J. A.; Aguíñiga-García, S.; Sanchez, A.; Zetina-Rejón, M.; Arreguín-Sánchez, F.; Tripp-Valdéz, A.; Galeana-Cortazár, A.

    2013-05-01

    Human activities have strong impacts on coastal ecosystems functioning through their effect on primary organic sources distributions and resulting biodiversity. Hence, it appears to be of utmost importance to quantify contribution of primary producers to sediment organic matter (SOM) spatial variability and its associated ichthyofauna. The Terminos lagoon (Gulf of Mexico) is a tropical estuary severely impacted by human activities even though of primary concern for its biodiversity, its habitats, and its resource supply. Stable isotope data (d13C, d15N) from mangrove, seaweed, seagrass, phytoplankton, ichthyofauna and SOM were sampled in four zones of the lagoon and the continental shelf through windy (November to February), dry (March to June) and rainy (July to October) seasons. Stable Isotope Analysis in R (SIAR) mixing model were used to determine relative contributions of the autotrophic sources to the ichthyofauna and SOM. Analysis of variance of ichthyofauna isotopic values showed significant differences (P < 0.001) in the four zones of lagoon despite the variability introduced by the windy, dry and rainy seasons. In lagoons rivers discharge zone, the mangrove contribution to ichthyofauna was 40% and 84% to SOM. Alternative use of habitat by ichthyofauna was evidenced since in the deep area of the lagoon (4 m), the contribution of mangrove to fish is 50%, and meanwhile contribution to SOM is only 77%. Although phytoplankton (43%) and seaweed (41%) contributions to the adjacent continental shelf ichthyofauna were the main organic sources, there was 37% mangrove contribution to SOM, demonstrating conspicuous terrigenous influence from lagoon ecosystem. Our results point toward organic sources spatial variations that regulate fish distribution. In Terminos lagoon, significant correlation (p-value = 0.2141 and r=0.79) of Ariopsis felis and Sphoeroides testudineus abundances and seaweed and seagrasses contributions (30-35%) during both dry and rainy seasons

  5. Methane fluxes from tropical coastal lagoons surrounded bymangroves, Yucatán, Mexico

    USGS Publications Warehouse

    Chuang, Pei-Chuan; Young, Megan B.; Dale, Andrew W.; Miller, Laurence G.; Herrera-Silveira, Jorge A; Paytan, Adina

    2017-01-01

    Methane concentrations in the water column and emissions to the atmosphere were determined for three tropical coastal lagoons surrounded by mangrove forests on the Yucatán Peninsula, Mexico. Surface water dissolved methane was sampled at different seasons over a period of 2 years in areas representing a wide range of salinities and anthropogenic impacts. The highest surface water methane concentrations (up to 8378 nM) were measured in a polluted canal associated with Terminos Lagoon. In Chelem Lagoon, methane concentrations were typically lower, except in the polluted harbor area (1796 nM). In the relatively pristine Celestún Lagoon, surface water methane concentrations ranged from 41 to 2551 nM. Methane concentrations were negatively correlated with salinity in Celestún, while in Chelem and Terminos high methane concentrations were associated with areas of known pollution inputs, irrespective of salinity. The diffusive methane flux from surface lagoon water to the atmosphere ranged from 0.0023 to 15 mmol CH4 m−2 d−1. Flux chamber measurements revealed that direct methane release as ebullition was up to 3 orders of magnitude greater than measured diffusive flux. Coastal mangrove lagoons may therefore be an important natural source of methane to the atmosphere despite their relatively high salinity. Pollution inputs are likely to substantially enhance this flux. Additional statistically rigorous data collected globally are needed to better consider methane fluxes from mangrove-surrounded coastal areas in response to sea level changes and anthropogenic pollution in order to refine projections of future atmospheric methane budgets.

  6. Biodiversity of Saline and Brakish Marshes of the Indian River Lagoon: Historic and Current Patterns

    NASA Technical Reports Server (NTRS)

    Schmalzer, Paul A.

    1995-01-01

    The Indian River Lagoon (IRL) crosses a zone of climatic transition. Historically, marshes dominated saline and brackish environments in the north of the lagoon, while mangroves became important to the south. Distribution of marsh communities was influenced by hydrology, salinity, soil characteristics, and fire, as well as periodic freezes. Marshes of the IRL have been greatly modified since the 1940s. Despite significant modifications, marsh plant species have not been lost from the region, but community and landscape patterns have been greatly modified and ecosystem processes altered.

  7. Biocomplexity in Mangrove Ecosystems

    NASA Astrophysics Data System (ADS)

    Feller, I. C.; Lovelock, C. E.; Berger, U.; McKee, K. L.; Joye, S. B.; Ball, M. C.

    2010-01-01

    Mangroves are an ecological assemblage of trees and shrubs adapted to grow in intertidal environments along tropical coasts. Despite repeated demonstration of their economic and societal value, more than 50% of the world's mangroves have been destroyed, 35% in the past two decades to aquaculture and coastal development, altered hydrology, sea-level rise, and nutrient overenrichment. Variations in the structure and function of mangrove ecosystems have generally been described solely on the basis of a hierarchical classification of the physical characteristics of the intertidal environment, including climate, geomorphology, topography, and hydrology. Here, we use the concept of emergent properties at multiple levels within a hierarchical framework to review how the interplay between specialized adaptations and extreme trait plasticity that characterizes mangroves and intertidal environments gives rise to the biocomplexity that distinguishes mangrove ecosystems. The traits that allow mangroves to tolerate variable salinity, flooding, and nutrient availability influence ecosystem processes and ultimately the services they provide. We conclude that an integrated research strategy using emergent properties in empirical and theoretical studies provides a holistic approach for understanding and managing mangrove ecosystems.

  8. Biocomplexity in mangrove ecosystems.

    PubMed

    Feller, I C; Lovelock, C E; Berger, U; McKee, K L; Joye, S B; Ball, M C

    2010-01-01

    Mangroves are an ecological assemblage of trees and shrubs adapted to grow in intertidal environments along tropical coasts. Despite repeated demonstration of their economic and societal value, more than 50% of the world's mangroves have been destroyed, 35% in the past two decades to aquaculture and coastal development, altered hydrology, sea-level rise, and nutrient overenrichment. Variations in the structure and function of mangrove ecosystems have generally been described solely on the basis of a hierarchical classification of the physical characteristics of the intertidal environment, including climate, geomorphology, topography, and hydrology. Here, we use the concept of emergent properties at multiple levels within a hierarchical framework to review how the interplay between specialized adaptations and extreme trait plasticity that characterizes mangroves and intertidal environments gives rise to the biocomplexity that distinguishes mangrove ecosystems. The traits that allow mangroves to tolerate variable salinity, flooding, and nutrient availability influence ecosystem processes and ultimately the services they provide. We conclude that an integrated research strategy using emergent properties in empirical and theoretical studies provides a holistic approach for understanding and managing mangrove ecosystems.

  9. Mangrove recruitment after forest disturbance is facilitated by herbaceous species in the Caribbean.

    PubMed

    McKee, Karen L; Rooth, Jill E; Feller, Ilka C

    2007-09-01

    Plant communities along tropical coastlines are often affected by natural and human disturbances, but little is known about factors influencing recovery. We focused on mangrove forests, which are among the most threatened ecosystems globally, to examine how facilitation by herbaceous vegetation might improve forest restoration after disturbance. We specifically investigated whether recovery of mangrove forests in harsh environments is accelerated by nurse plants and whether the beneficial effects are species-specific. Quantification of standardized effects allowed comparisons across performance parameters and over time for: (1) net effect of each herbaceous species on mangrove survival and growth, (2) effects of pre- and post-establishment factors associated with each herbaceous species, and (3) need for artificial planting to enhance growth or survival of mangrove seedlings. Mangrove recruitment in a clear-cut forest in Belize was accelerated by the presence of Sesuvium portulacastrum (succulent forb) and Distichlis spicata (grass), two coastal species common throughout the Caribbean region. The net effect of herbaceous vegetation was positive, but the magnitude of effects on mangrove survival and growth differed by species. Because of differences in their vegetative structure and other features, species effects on mangroves also varied by mechanism: (1) trapping of dispersing propagules (both species), (2) structural support of the seedling (Distichlis), and/or (3) promotion of survival (Sesuviumn) or growth (Distichlis) through amelioration of soil conditions (temperature, aeration). Artificial planting had a stronger positive effect on mangrove survival than did edaphic conditions, but planting enhanced mangrove growth more in Sesuvium than in Distichlis patches. Our study indicates that beneficial species might be selected based on features that provide multiple positive effects and that species comparisons may be improved using standardized effects. Our

  10. Sedimentation in lagoon waters (Case study on Segara Anakan Lagoon)

    NASA Astrophysics Data System (ADS)

    Sari, Lilik Kartika; Adrianto, Luky; Soewardi, Kadarwan; Atmadipoera, Agus S.; Hilmi, Endang

    2016-05-01

    This study aims to demonstrate the effect of sedimentation on waters area that serves as an advocate for life. It is included in the category to be wary considering these conditions will reduce the quality of life and threaten the life and survival of endemic biota. Observations rate of sedimentation since April 2014 until March 2015 performed at 6 stations that are considered to represent the condition of the lagoon. The observations for rate of sedimentation was conducted twice in a month for one year. Oceanographic parameters was taken by CTD (Conductivity, Temperature, and Depth) sensor in two seasons, at the height of the rainy season, March 2014 and August 2014. Results showed that the aquatic area more narrow characterized by changes in the outside line of the island visible on the image observation for two decades.

  11. Odor control in lagoons.

    PubMed

    Zhang, X L; Yan, S; Tyagi, R D; Surampalli, R Y

    2013-07-30

    Lagoons are widely used in rural area for wastewater treatment; however, the odor problem has hampered its application. The root of odor emission from lagoons varies from one to another. The key of controlling the odor is to find out the cause and accordingly provide strategies. Various physical, chemical, and biological methods have been reported and applied for odor control. Physical technologies such as masking, capturing and sorption are often employed to mitigate the pressure from compliant while not to cut off the problem. Chemical technologies which act rapidly and efficiently in odor control, utilize chemicals to damage the odorant production root or convert odorant to odorless substances. Biological methods such as aeration, biocover and biofiltration control the odor by enhancing aerobic condition or developing methanogens in lagoon, and biologically decomposing the odorants. Comparing to physical and chemical methods, biological methods are more feasible. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Mangroves - what are they worth

    SciTech Connect

    Christensen, B.

    1983-01-01

    This paper is based on a study for FAO and on the management and utilization of mangroves in Asia and the Pacific. Land use options are examined in relation to the different roles which mangroves play (provision of firewood, charcoal, timber and pulp; wildlife; fisheries and aquaculture; and agriculture). Special attention is paid to mangrove management in Malaysia. (Refs 26)

  13. Global Status of Mangrove Ecosystems.

    ERIC Educational Resources Information Center

    Saenger, P., Ed.; And Others

    1983-01-01

    Mangroves are the characteristic littoral plant formations of tropical/subtropical sheltered coastlines. Presented is a detailed report which discusses uses made of mangrove ecosystems and attempts to resolve conflicts arising from these uses. Areas considered include cause/consequence of mangrove destruction, legislative/administrative aspects,…

  14. Global Status of Mangrove Ecosystems.

    ERIC Educational Resources Information Center

    Saenger, P., Ed.; And Others

    1983-01-01

    Mangroves are the characteristic littoral plant formations of tropical/subtropical sheltered coastlines. Presented is a detailed report which discusses uses made of mangrove ecosystems and attempts to resolve conflicts arising from these uses. Areas considered include cause/consequence of mangrove destruction, legislative/administrative aspects,…

  15. Growth performance of planted mangroves in the Philippines: revisiting forest management strategies.

    PubMed

    Samson, Maricar S; Rollon, Rene N

    2008-06-01

    The effort toward restoring lost mangroves in the Philippines has been commendably immense, specifically during the past two decades. In light of such, it is important to evaluate outcomes and, where appropriate, apply the lessons learned to the current strategies in mangrove forest management. This article synthesizes the results from several research projects assessing the performance of planted mangroves across the country. Overall, there is a widespread tendency to plant mangroves in areas that are not the natural habitat of mangroves, converting mudflats, sandflats, and seagrass meadows into often monospecific Rhizophora mangrove forests. In these nonmangrove areas, the Rhizophora seedlings experienced high mortality. Of the few that survived (often through persistent and redundant replanting), the young Rhizophora individuals planted in these nonmangrove and often low intertidal zones had dismally stunted growth relative to the corresponding growth performance of individuals thriving at the high intertidal position and natural mangrove sites. From this evidence, this article argues that a more rational focus of the restoration effort should be the replanting of mangroves in the brackish-water aquaculture pond environments, the original habitat of mangroves. For such, a number of management options can be explored, the implementation of which will ultimately depend on the political will of local and national governments.

  16. A Lesson from Mangroves.

    ERIC Educational Resources Information Center

    Davis, Stephen

    1987-01-01

    Discusses the importance of interpretive programs in the Northern Territory of Australia. Describes the typical interpretive approach of local school science curricula, which serve 20,000 Aboriginal children. Addresses the curriculum framework, learning strategies, and process skill development, illustrating them through a lesson on mangroves. (TW)

  17. Mangrove bacterial richness

    PubMed Central

    Cleary, Daniel FR; Calado, Ricardo; Costa, Rodrigo

    2011-01-01

    Mangroves are complex and dynamic ecosystems varying in salinity, water level and nutrient availability; they also contain diverse and distinct microbial communities. Studies of microbes and their interactions with other ecosystem components (e.g., tree roots) are critical for our understanding of mangrove ecosystem functioning and remediation. Using a barcoding pyrosequencing approach, we previously noted the persistence of terrestrial bacterial populations on mangrove roots when nursery raised saplings were transplanted back to their natural environment. Here we go into further detail about the potential functional associations of bacterial guilds with distinct mangrove microhabitats including the rhizosphere. We also use a nonparametric richness estimator to show that estimated operational taxonomic unit (OTU) richness is more than twice that observed. In the transplant microhabitat, our estimate suggests that there are almost 7,000 OTU's for a sample size of 10,400 individual sequences with no sign of an asymptote, indicating that “true” richness for this microhabitat is substantially larger. Results on the number of bacterial OTU's should, however, be viewed with caution given that the barcoding pyrosequencing technique used can yield sequencing artifacts that may inflate richness estimates if not properly removed. PMID:21966560

  18. A Lesson from Mangroves.

    ERIC Educational Resources Information Center

    Davis, Stephen

    1987-01-01

    Discusses the importance of interpretive programs in the Northern Territory of Australia. Describes the typical interpretive approach of local school science curricula, which serve 20,000 Aboriginal children. Addresses the curriculum framework, learning strategies, and process skill development, illustrating them through a lesson on mangroves. (TW)

  19. Lagoon Restoration Project: Final report

    SciTech Connect

    1995-03-01

    This project is a multiyear effort focusing on energy flow in the Palace of Fine Arts lagoon just outside the Exploratorium in San Francisco. Phase 1 was a pilot study to determine the feasibility of improving biological energy flow through the small freshwater lagoon, using the expertise and resources of an environmental artist in collaboration with museum biologists and arts department staff. The primary outcome of Phase 1 is an experimental fountain exhibit inside the museum designed by public artist Laurie Lundquist with Exploratorium staff. This fountain, with signage, functions both as a model for natural aeration and filtration systems and as a focal point for museum visitors to learn about how biological processes cycle energy through aquatic systems. As part of the study of the lagoon`s health, volunteers continued biweekly bird consus from March through September, 1994. The goal was to find out whether the poor water quality of the lagoon is affecting the birds. Limited dredging was undertaken by the city Parks and Recreation Department. However, a more peermanent solution to the lagoon`s ecological problems would require an ambitious redesign of the lagoon.

  20. The tale of four lagoons

    USDA-ARS?s Scientific Manuscript database

    Anaerobic lagoons are a common management practice in the Carolinas for the treatment of swine wastewater. Although these lagoons were once thought to be relatively simple; their physical, chemical, and biological processes are actually very sophisticated. To get a better understanding of the microb...

  1. Epiphytic diatoms associated with red mangrove (Rhizophora mangle) prop roots in Bahía Magdalena, Baja California Sur, Mexico.

    PubMed

    Siqueiros Beltrones, D A; López Fuerte, F O

    2006-06-01

    The first floristic inventory of benthic diatoms is provided for the Bahia Magdalena-Bahia Almejas lagoon system. Samplings were carried out during November of 1999. The oxydized samples were mounted permanently. Eighty six diatom taxa were identified, out of which 59 are new records for the Bahia Magdalena area, and 12 taxa are new for the Baja California peninsula. Taxa recorded previously as rare in other substrata are common or abundant on the epiphytic macroalgae of mangrove prop roots. Other species are mainly epipelic forms, while 24 are commonly found as tychoplankton in the area. Certain taxa appear to be characteristic of mangrove systems in general.

  2. Biotic interactions mediate the expansion of black mangrove (Avicennia germinans) into salt marshes under climate change.

    PubMed

    Guo, Hongyu; Zhang, Yihui; Lan, Zhenjiang; Pennings, Steven C

    2013-09-01

    Many species are expanding their distributions to higher latitudes due to global warming. Understanding the mechanisms underlying these distribution shifts is critical for better understanding the impacts of climate changes. The climate envelope approach is widely used to model and predict species distribution shifts with changing climates. Biotic interactions between species, however, may also influence species distributions, and a better understanding of biotic interactions could improve predictions based solely on climate envelope models. Along the northern Gulf of Mexico coast, USA, subtropical black mangrove (Avicennia germinans) at the northern limit of its distribution grows sympatrically with temperate salt marsh plants in Florida, Louisiana, and Texas. In recent decades, freeze-free winters have led to an expansion of black mangrove into salt marshes. We examined how biotic interactions between black mangrove and salt marsh vegetation along the Texas coast varied across (i) a latitudinal gradient (associated with a winter-temperature gradient); (ii) the elevational gradient within each marsh (which creates different marsh habitats); and (iii) different life history stages of black mangroves (seedlings vs. juvenile trees). Each of these variables affected the strength or nature of biotic interactions between black mangrove and salt marsh vegetation: (i) Salt marsh vegetation facilitated black mangrove seedlings at their high-latitude distribution limit, but inhibited black mangrove seedlings at lower latitudes; (ii) mangroves performed well at intermediate elevations, but grew and survived poorly in high- and low-marsh habitats; and (iii) the effect of salt marsh vegetation on black mangroves switched from negative to neutral as black mangroves grew from seedlings into juvenile trees. These results indicate that the expansion of black mangroves is mediated by complex biotic interactions. A better understanding of the impacts of climate change on ecological

  3. KENNEDY SPACE CENTER, FLA. - As Karen Holloway-Adkins, KSC wildlife specialist, begins a tour of the Banana River, this alligator sunning itself attracts attention. Holloway-Adkins is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

    NASA Image and Video Library

    2004-02-05

    KENNEDY SPACE CENTER, FLA. - As Karen Holloway-Adkins, KSC wildlife specialist, begins a tour of the Banana River, this alligator sunning itself attracts attention. Holloway-Adkins is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

  4. KENNEDY SPACE CENTER, FLA. - Karen Holloway-Adkins, KSC wildlife specialist, at the helm of a boat on the Banana River, heads for a research area. She is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

    NASA Image and Video Library

    2004-02-05

    KENNEDY SPACE CENTER, FLA. - Karen Holloway-Adkins, KSC wildlife specialist, at the helm of a boat on the Banana River, heads for a research area. She is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

  5. KENNEDY SPACE CENTER, FLA. - Karen Holloway-Adkins, KSC wildlife specialist, shows a sample of the sea grass she collected from the floor of the Banana River. She is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

    NASA Image and Video Library

    2004-02-05

    KENNEDY SPACE CENTER, FLA. - Karen Holloway-Adkins, KSC wildlife specialist, shows a sample of the sea grass she collected from the floor of the Banana River. She is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

  6. KENNEDY SPACE CENTER, FLA. - Karen Holloway-Adkins, KSC wildlife specialist, holds a sample of the sea grass she collected from the floor of the Banana River. She is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

    NASA Image and Video Library

    2004-02-05

    KENNEDY SPACE CENTER, FLA. - Karen Holloway-Adkins, KSC wildlife specialist, holds a sample of the sea grass she collected from the floor of the Banana River. She is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

  7. KENNEDY SPACE CENTER, FLA. - Karen Holloway-Adkins, KSC wildlife specialist, takes the helm on the boat as she begins a tour of the Banana River. She is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

    NASA Image and Video Library

    2004-02-05

    KENNEDY SPACE CENTER, FLA. - Karen Holloway-Adkins, KSC wildlife specialist, takes the helm on the boat as she begins a tour of the Banana River. She is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

  8. Using remote sensing to study mangroves spatial dynamics under increased nitrogen availability and lower salinity conditions

    NASA Astrophysics Data System (ADS)

    Silvestri, S.; Whigham, D.; Laanbroek, R.; Rains, M. C.; Verhoeven, J.

    2014-12-01

    The impact of a strong change in the hydrologic conditions of an impoundment in the Indian River Lagoon (FL) dominated by Black mangrove (Avicennia germinans) has been monitored through field campaigns and remote sensing data analysis. The management solution adopted since the spring of 2009 to reduce the number of noxious insects involved pumping estuarine water in the spring and summer seasons. Satellite and airborne data with medium to high spatial resolution have been used to perform a change detection analysis and study the evolution of the spatial distribution of mangrove trees. Empirical relations of vegetation indexes with field data collected over time have been determined, and specifically the correlation with leaf production, branch length increment, soil moisture and salinity, soil NH4 concentration and nitrification/denitrification processes. The field data had already shown how locally the higher nitrogen availability and the lower soil salinity increased Black mangrove growth mainly in areas with dwarf and sparse mangrove cover. The use of high spatial resolution remote sensing has been of key importance to extend this result at the impoundment scale, showing how mangroves expanded overtime.

  9. [Population ecology of Crocodylus acutus (Reptilia: Crocodylidae) in Palmasola lagoon, Oaxaca, Mexico].

    PubMed

    García-Grajales, Jesús; Silva, Alejandra Buenrostro

    2014-03-01

    Population ecology of Crocodylus acutus (Reptilia: Crocodylidae) in Palmasola lagoon, Oaxaca, Mexico. Abundance and population structure are important parameters to evaluate and compare the conservation status of a population over time in a given area. This study describes the population abundance and structure of Crocodylus acutus in Palmasola lagoon, Oaxaca. The field works consisted of night surveys during the new moon phase, between the 21:00 and 24:00h. These were conducted during the dry and wet seasons and counted the number of individuals to obtain population estimates. Recorded encounter rates ranged from 32 to 109.3ind./ km in 40 journeys deployed with an average time of 18 minutes browsing. The estimated population size using the Messel's model ranged from 32.7 to 93 individuals. For both seasons, there was a marked dominance of subadults, followed by juveniles and to a lesser extent adult individuals, as well as undetermined individuals (i.e. unknown body/size/length), in both seasons. There was also a significant association with mangrove areas (26.1%) by juveniles; the subadults's individual use of superficial water (22.7%) and mangrove areas (15.7%); meanwhile the adults were observed on superficial water (9.7%). This information contributes to our understanding of the population ecology of C. acutus in the Palmasola lagoon where the estimated population size seems to show higher values when compared to other reports in the country.

  10. Monitoring coral reefs, seagrasses and mangroves in Costa Rica (CARICOMP).

    PubMed

    Cortés, Jorge; Fonseca, Ana C; Nivia-Ruiz, Jaime; Nielsen-Muñoz, Vanessa; Samper-Villarreal, Jimena; Salas, Eva; Martínez, Solciré; Zamora-Trejos, Priscilla

    2010-10-01

    The coral reefs, seagrasses and mangroves from the Costa Rican Caribbean coast have been monitored since 1999 using the CARICOMP protocol. Live coral cover at Meager Shoal reef bank (7 to 10 m depth) at the Parque Nacional Cahuita (National Park), increased from 13.3% in 1999, to 28.2% in 2003, but decreased during the next 5 years to around 17.5%. Algal cover increased significantly since 2003 from 36.6% to 61.3% in 2008. The density of Diadema antillarum oscillated between 2 and 7ind/m2, while Echinometra viridis decreased significantly from 20 to 0.6ind/m2. Compared to other CARICOMP sites, live coral cover, fish diversity and density, and sea urchin density were low, and algal cover was intermediate. The seagrass site, also in the Parque Nacional Cahuita, is dominated by Thalassia testudinum and showed an intermediate productivity (2.7 +/- 1.15 g/m2/d) and biomass (822.8 +/- 391.84 g/m2) compared to other CARICOMP sites. Coral reefs and seagrasses at the Parque Nacional Cahuita continue to be impacted by high sediment loads from terrestrial origin. The mangrove forest at Gandoca, within the Refugio Nacional de Vida Silvestre Gandoca-Manzanillo (National Wildlife Refuge), surrounds a lagoon and it is dominated by the red mangrove, Rhizophora mangle. Productivity and flower production peak was in July. Biomass (14 kg/m2) and density (9.0 +/- 0.58 trees/100 m2) in Gandoca were relatively low compared to other CARICOMP sites, while productivity in July in Costa Rica (4 g/m2/d) was intermediate, similar to most CARICOMP sites. This mangrove is expanding and has low human impact thus far. Management actions should be taken to protect and preserve these important coastal ecosystems.

  11. Circulation in Enewetak Atoll lagoon

    SciTech Connect

    Atkinson, M.; Smith, S.V.; Stroup, E.D.

    1981-11-01

    Currents at Enewetak Atoll, Marshall Islands, were measured on the reef margins, in the channels, and in the lagoon. Lagoon circulation is dominated by wind-driven downwind surface flow and an upwind middepth return flow. This wind-driven flow has the characteristics of an Ekman spiral in an enclosed sea. Lagoon flushing is accomplished primarily by surf-driven water input over the windward (eastern) reefs and southerly drift out the South Channel. Mean water residence time is 1 month, while water entering the northern portion of the atoll takes about 4 months to exit.

  12. Use of Mangroves by Lemurs.

    PubMed

    Gardner, Charlie J

    Despite an increasing recognition of the ecosystem services provided by mangroves, we know little about their role in maintaining terrestrial biodiversity, including primates. Madagascar's lemurs are a top global conservation priority, with 94 % of species threatened with extinction, but records of their occurrence in mangroves are scarce. I used a mixed-methods approach to collect published and unpublished observations of lemurs in mangroves: I carried out a systematic literature search and supplemented this with a targeted information request to 1243 researchers, conservation and tourism professionals, and others who may have visited mangroves in Madagascar. I found references to, or observations of, at least 23 species in 5 families using mangroves, representing >20% of lemur species and >50% of species whose distributions include mangrove areas. Lemurs used mangroves for foraging, sleeping, and traveling between terrestrial forest patches, and some were observed as much as 3 km from the nearest permanently dry land. However, most records were anecdotal and thus tell us little about lemur ecology in this habitat. Mangroves are more widely used by lemurs than has previously been recognized and merit greater attention from primate researchers and conservationists in Madagascar.

  13. Ni cycling in mangrove sediments from New Caledonia

    NASA Astrophysics Data System (ADS)

    Noël, Vincent; Morin, Guillaume; Juillot, Farid; Marchand, Cyril; Brest, Jessica; Bargar, John R.; Muñoz, Manuel; Marakovic, Grégory; Ardo, Sandy; Brown, Gordon E.

    2015-11-01

    Covering more than 70% of tropical and subtropical coastlines, mangrove intertidal forests are well known to accumulate potentially toxic trace metals in their sediments, and thus are generally considered to play a protective role in marine and lagoon ecosystems. However, the chemical forms of these trace metals in mangrove sediments are still not well known, even though their molecular-level speciation controls their long-term behavior. Here we report the vertical and lateral changes in the chemical forms of nickel, which accumulates massively in mangrove sediments downstream from lateritized ultramafic deposits from New Caledonia, where one of nature's largest accumulations of nickel occurs. To accomplish this we used Ni K-edge Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy data in combination with microscale chemical analyses using Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy (SEM-EDXS). After Principal Component and Target Transform analyses (PCA-TT), the EXAFS data of the mangrove sediments were reliably least-squares fitted by linear combination of 3-components chosen from a large model compound spectral database including synthetic and natural Ni-bearing sulfides, clay minerals, oxyhydroxides, and organic complexes. Our results show that in the inland salt flat Ni is hosted in minerals inherited from the eroded lateritic materials, i.e. Ni-poor serpentine (44-58%), Ni-rich talc (20-31%), and Ni-goethite (18-24%). In contrast, in the hydromorphic sediments beneath the vegetated Avicennia and Rhizophora stands, a large fraction of Ni is partly redistributed into a neoformed smectite pool (20-69% of Ni-montmorillonite), and Ni speciation significantly changes with depth in the sediment. Indeed, Ni-rich talc (25-56%) and Ni-goethite (15-23%) disappear below ∼15 cm depth in the sediment and are replaced by Ni-sorbed pyrite (23-52%) in redox-active intermediate depth layers and by pyrite (34-55%) in the deepest

  14. Water cycle and salinity dynamics in the mangrove forests of Europa and Juan de Nova Islands, southwest Indian Ocean.

    PubMed

    Lambs, Luc; Mangion, Perrine; Mougin, Eric; Fromard, François

    2016-01-30

    The functioning of mangrove forests found on small coralline islands is characterized by limited freshwater inputs. Here, we present data on the water cycling of such systems located on Europa and Juan de Nova Islands, Mozambique Channel. In order to better understand the water cycle and mangrove growth conditions, we have analysed the hydrological and salinity dynamics of the systems by gauge pressure and isotopic tracing (δ18O and δ2H values). Both islands have important seawater intrusion as measured by the water level change and the high salinities in the karstic ponds. Europa Island displays higher salinity stress, with its inner lagoon, but presents a pluri-specific mangrove species formation ranging from shrub to forest stands. No freshwater signal could be detected around the mangrove trees. On Juan de Nova Island, the presence of sand and detrital sediment allows the storage of some amount of rainfall to form a brackish groundwater. The mangrove surface area is very limited with only small mono-specific stands being present in karstic depression. On the drier Europa Island, the salinity of all the water points is equal to or higher than that of the seawater, and on Juan de Nova the groundwater salinity is lower (5 to 20 PSU). This preliminary study shows that the karstic pothole mangroves exist due to the sea connection through the fractured coral and the high tidal dynamics.

  15. Natural Products from Mangrove Actinomycetes

    PubMed Central

    Xu, Dong-Bo; Ye, Wan-Wan; Han, Ying; Deng, Zi-Xin; Hong, Kui

    2014-01-01

    Mangroves are woody plants located in tropical and subtropical intertidal coastal regions. The mangrove ecosystem is becoming a hot spot for natural product discovery and bioactivity survey. Diverse mangrove actinomycetes as promising and productive sources are worth being explored and uncovered. At the time of writing, we report 73 novel compounds and 49 known compounds isolated from mangrove actinomycetes including alkaloids, benzene derivatives, cyclopentenone derivatives, dilactones, macrolides, 2-pyranones and sesquiterpenes. Attractive structures such as salinosporamides, xiamycins and novel indolocarbazoles are highlighted. Many exciting compounds have been proven as potential new antibiotics, antitumor and antiviral agents, anti-fibrotic agents and antioxidants. Furthermore, some of their biosynthetic pathways have also been revealed. This review is an attempt to consolidate and summarize the past and the latest studies on mangrove actinomycetes natural product discovery and to draw attention to their immense potential as novel and bioactive compounds for marine drugs discovery. PMID:24798926

  16. Mosquito Lagoon environmental resources inventory

    NASA Technical Reports Server (NTRS)

    Provancha, Jane A.; Hall, Carlton R.; Oddy, Donna M.

    1992-01-01

    This document provides a synopsis of biotic and abiotic data collected in the Mosquito Lagoon area in relation to water quality. A holistic ecological approach was used in this review to allow for summaries of climate, land use, vegetation, geohydrology, water quality, fishes, sea turtles, wading birds, marine mammals, invertebrates, shellfish, and mosquito control. The document includes a bibliographic database list of 157 citations that have references to the Mosquito Lagoon, many of which were utilized in development of the text.

  17. Sediment characteristics and water quality in the two hyper-saline lagoons along the Red Sea coast of Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Rasul, Najeeb; Al-Farawati, Radwan; Al-Harbi, Omer; Naser Qutub, Abdul

    2013-04-01

    The two hyper-saline Shoaiba lagoons, Khawr ash Shaibah al Masdudah (northern lagoon) and Khawr ash Shaibah al Maftuhah (southern lagoon) have a unique environmental set-up because no rivers or wadis flow into the lagoons and therefore detrital material to the lagoons is lacking and most of the sediments are indigenous carbonates. The biogenic material is mostly derived from coral debris, coralline algae and molluscs abundant in gravel and sand size fractions. The evaporite deposits from the adjoining sabkhas are transported to the lagoon during tidal cycles. Carbonate is abundant in the form of aragonite and High Mg-calcite indicating carbonate to be recent and formed under shallow water conditions. In general, the sediments are the result of the mechanical breakdown of molluscs and coral reefs by either human activity or by coral boring marine organisms and physical processes such as tidal and wind generated currents. Strong currents dominate only the deeper part at the entrance of the lagoons that causes the winnowing of the finer sediments, and its transportation during flooding and ebbing. Shallow depths averaging 3 m, wind and tidal stirring are the main forces preventing the lagoons from developing stratification resulting in a well-mixed body of water. The shallow depth of the lagoons keep the turbidity levels higher, whereas salinity as high as 52 ‰ and water temperature as high as 38 °C helps in the formation of halite at the periphery. The cyclical inundation of sabkhas by a thin sheet of water during tidal cycles is important in understanding the ecological consequence. Mangrove stands in the lagoons act as a source of nutrients to the flora and fauna inhabiting the lagoons. The configurations of the mouth of the lagoons influence the tidal currents, including the sediment and water movement. The tidal current is enhanced as it enters the lagoons, in response to the funneling effect caused by the narrow channel. The current diffuses as the entrance

  18. Use of deep water lagoons for reducing sewage toxicity prior to wastewater treatment

    SciTech Connect

    Shaw, J.R.; Zuiderveen, J.A.; Belcher, B.; McGinley, P.; Birge, W.J.

    1994-12-31

    Investigations were conducted to determine the effectiveness of deep lagoons as a means of wastewater pretreatment. A lagoon system associated with a wastewater treatment plant (WWTP) was selected for study and parameters identified for monitoring included toxicity, metals, total suspended solids (TSS) and ammonia. This system included two lagoons, with 7--15 day hydraulic retention times, fed sequentially with untreated water. Toxicity and other parameters were measured for raw influent water, the two lagoon outfalls, and the final WWTP effluent. In seven-day chronic tests with Ceriodaphnia dubia, the NOEC of influent water was as low as 20%, and 100% mortality occurred at 40%. Outfall from the first deep water lagoon showed reduced toxicity. The NOEC was > 50% but complete mortality occurred in undiluted effluent. Further reduction in toxicity occurred in the second lagoon. Its undiluted effluent had no effect on survival, but did markedly reduce fecundity. The final effluent discharged from the treatment plant affected neither survival nor fecundity. Results of this investigation support the use of deep water lagoons as an effective and economical means of pretreating wastewater. This approach offers promise for municipal waters, industrial effluents and stormwater runoff.

  19. Mangrove recruitment after forest disturbance is facilitated by herbaceous species in the Caribbean

    USGS Publications Warehouse

    McKee, K.L.; Rooth, J.E.; Feller, Ilka C.

    2007-01-01

    Plant communities along tropical coastlines are often affected by natural and human disturbances, but little is known about factors influencing recovery. We focused on mangrove forests, which are among the most threatened ecosystems globally, to examine how facilitation by herbaceous vegetation might improve forest restoration after disturbance. We specifically investigated whether recovery of mangrove forests in harsh environments is accelerated by nurse plants and whether the beneficial effects are species-specific. Quantification of standardized effects allowed comparisons across performance parameters and over time for: (1) net effect of each herbaceous species on mangrove survival and growth, (2) effects of pre- and post-establishment factors associated with each herbaceous species, and (3) need for artificial planting to enhance growth or survival of mangrove seedlings. Mangrove recruitment in a clear-cut forest in Belize was accelerated by the presence of Sesuvium portulacastrum (succulent forb) and Distichlis spicata (grass), two coastal species common throughout the Caribbean region. The net effect of herbaceous vegetation was positive, but the magnitude of effects on mangrove survival and growth differed by species. Because of differences in their vegetative structure and other features, species effects on mangroves also varied by mechanism: (1) trapping of dispersing propagules (both species), (2) structural support of the seedling (Distichlis), and/or (3) promotion of survival (Sesuvium) or growth (Distichlis) through amelioration of soil conditions (temperature, aeration). Artificial planting had a stronger positive effect on mangrove survival than did edaphic conditions, but planting enhanced mangrove growth more in Sesuvium than in Distichlis patches. Our study indicates that beneficial species might be selected based on features that provide multiple positive effects and that species comparisons may be improved using standardized effects. Our

  20. The metal content of bivalve molluscs of a coastal lagoon of NW Mexico.

    PubMed

    Frías-Espericueta, Martín G; Osuna-López, José I; Voltolina, Domenico; López-López, Gabriel; Izaguirre-Fierro, Gildardo; Muy-Rangel, María D

    2008-01-01

    The lagoonal system Altata-Ensenada del Pabellón supports important traditional fisheries and mollusc cultures and receives urban and agricultural effluents. The annual mean Cd contents of the oyster and mussel Crassostrea gigas and Mytella strigata of the inner mangrove swamps were higher than that of the clam Megapitaria squalida, which lives in areas under marine influence. Crassostrea corteziensis had the highest Cu and Zn contents, showing that it is a strong accumulator of both metals and especially of Zn, and there were no significant differences in the Pb content of the three species.

  1. Intra- and interspecific facilitation in mangroves may increase resilience to climate change threats

    PubMed Central

    Huxham, Mark; Kumara, Marappullige P.; Jayatissa, Loku P.; Krauss, Ken W.; Kairo, James; Langat, Joseph; Mencuccini, Maurizio; Skov, Martin W.; Kirui, Bernard

    2010-01-01

    Mangroves are intertidal ecosystems that are particularly vulnerable to climate change. At the low tidal limits of their range, they face swamping by rising sea levels; at the high tidal limits, they face increasing stress from desiccation and high salinity. Facilitation theory may help guide mangrove management and restoration in the face of these threats by suggesting how and when positive intra- and interspecific effects may occur: such effects are predicted in stressed environments such as the intertidal, but have yet to be shown among mangroves. Here, we report the results of a series of experiments at low and high tidal sites examining the effects of mangrove density and species mix on seedling survival and recruitment, and on the ability of mangroves to trap sediment and cause surface elevation change. Increasing density significantly increased the survival of seedlings of two different species at both high and low tidal sites, and enhanced sediment accretion and elevation at the low tidal site. Including Avicennia marina in species mixes enhanced total biomass at a degraded high tidal site. Increasing biomass led to changed microenvironments that allowed the recruitment and survival of different mangrove species, particularly Ceriops tagal. PMID:20513720

  2. Intra- and interspecific facilitation in mangroves may increase resilience to climate change threats.

    PubMed

    Huxham, Mark; Kumara, Marappullige P; Jayatissa, Loku P; Krauss, Ken W; Kairo, James; Langat, Joseph; Mencuccini, Maurizio; Skov, Martin W; Kirui, Bernard

    2010-07-12

    Mangroves are intertidal ecosystems that are particularly vulnerable to climate change. At the low tidal limits of their range, they face swamping by rising sea levels; at the high tidal limits, they face increasing stress from desiccation and high salinity. Facilitation theory may help guide mangrove management and restoration in the face of these threats by suggesting how and when positive intra- and interspecific effects may occur: such effects are predicted in stressed environments such as the intertidal, but have yet to be shown among mangroves. Here, we report the results of a series of experiments at low and high tidal sites examining the effects of mangrove density and species mix on seedling survival and recruitment, and on the ability of mangroves to trap sediment and cause surface elevation change. Increasing density significantly increased the survival of seedlings of two different species at both high and low tidal sites, and enhanced sediment accretion and elevation at the low tidal site. Including Avicennia marina in species mixes enhanced total biomass at a degraded high tidal site. Increasing biomass led to changed microenvironments that allowed the recruitment and survival of different mangrove species, particularly Ceriops tagal.

  3. A Trophic Model of a Sandy Barrier Lagoon at Chiku in Southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, H.-J.; Shao, K.-T.; Kuo, S.-R.; Hsieh, H.-L.; Wong, S.-L.; Chen, I.-M.; Lo, W.-T.; Hung, J.-J.

    1999-05-01

    Using the ECOPATH 3.0 software system, a balanced trophic model of a sandy barrier lagoon with intensive fishery activities at Chiku in tropical Taiwan was constructed. The lagoon model comprised 13 compartments. Trophic levels of the compartments varied from 1·0 for primary producers and detritus to 3·6 for piscivorous fish. Hanging-cultured oysters accounted for 39% of the harvestable fishery biomass and were the most important fishery species. The most prominent group in terms of biomass and energy flow in the lagoon was herbivorous zooplankton. Manipulations of the biomass of herbivorous zooplankton would have a marked impact on most compartments. Both total system throughput and fishery yield per unit area were high when compared to other reported marine ecosystems. This appears mainly due to high planktonic primary production, which is probably promoted by enriched river discharges draining mangroves and aquaculture ponds. Consequently, more than half of the total system throughput originates from primary producers in the lagoon. Although half of the primary production was not immediately used by upper trophic levels and flowed into the detrital pool, most of the detritus was directly consumed, passed up the food web and was exported to the fishery. Thus only a small proportion of energy was recycled through detritus pathways. This mechanism produces short pathways with high trophic efficiencies at higher trophic levels. The high fishery yield in the lagoon is due to high primary production and short pathways. This is the first model of a tropical sandy barrier lagoon with intensive fishery activities and thus may serve as a basis for future comparisons and ecosystem management.

  4. The Influence of Wind and Tide on the Hydrodynamics of a Highly Frictional Coastal Lagoon System

    NASA Astrophysics Data System (ADS)

    Polanco-Arias, C.; Marino-Tapia, I.; Enriquez, C.

    2016-02-01

    This study is focused on the influence of wind and tide on the hydrodynamics of a tropical coastal lagoon in Telchac, Yucatan, Mexico. The system is very shallow (z < 1m) and covered with a rim of mangrove forests, both aspects that enhance its frictional characteristics. The lagoon is an important habitat for the exotic flamingo birds and several species of fish, but also is used for fishing and serves as a harbor for small boats. Water level and velocity data gathered during one month in the summer of 2009, shows the expected attenuation of the tidal signal in the head of the system, but during the final ten days of the campaign there is an unusual behavior where the water level in the lagoon head was between 16% and 33% bigger than in the lagoon mouth. Analysis of the data shows a high coherence between the sea level and the wind velocity, primarily at diurnal frequencies. This reinforces the hypothesis of a synchronization between strong sea breezes and the predominant diurnal tide in such a way that amplification of the diurnal signal can occur at the head. Numerical simulations using the Delft3D model are performed to confirm this hypothesis and to better understand the conditions under which such phenomenon can occur. The effects of basin orientation, shape and depth are investigated with the numerical model.

  5. Plant-plant interactions in a subtropical mangrove-to-marsh transition zone: effects of environmental drivers

    USGS Publications Warehouse

    Howard, Rebecca J.; Krauss, Ken W.; Cormier, Nicole; Day, Richard H.; Biagas, Janelda M.; Allain, Larry K.

    2015-01-01

    Questions Does the presence of herbaceous vegetation affect the establishment success of mangrove tree species in the transition zone between subtropical coastal mangrove forests and marshes? How do plant–plant interactions in this transition zone respond to variation in two primary coastal environmental drivers? Location Subtropical coastal region of the southern United States. Methods We conducted a greenhouse study to better understand how abiotic factors affect plant species interactions in the mangrove-to-marsh transition zone, or ecotone. We manipulated salinity (fresh, brackish or salt water) and hydrologic conditions (continuously saturated or 20-cm tidal range) to simulate ecotonal environments. Propagules of the mangroves Avicennia germinans and Laguncularia racemosa were introduced to mesocosms containing an established marsh community. Both mangrove species were also introduced to containers lacking other vegetation. We monitored mangrove establishment success and survival over 22 mo. Mangrove growth was measured as stem height and above-ground biomass. Stem height, stem density and above-ground biomass of the dominant marsh species were documented. Results Establishment success of A. germinans was reduced under saturated saltwater conditions, but establishment of L. racemosa was not affected by experimental treatments. There was complete mortality of A. germinans in mesocosms under freshwater conditions, and very low survival of L. racemosa. In contrast, survival of both species in monoculture under freshwater conditions exceeded 62%. The marsh species Distichlis spicata and Eleocharis cellulosa suppressed growth of both mangroves throughout the experiment, whereas the mangroves did not affect herbaceous species growth. The magnitude of growth suppression by marsh species varied with environmental conditions; suppression was often higher in saturated compared to tidal conditions, and higher in fresh and salt water compared to

  6. Santa Margarita Lagoon Water Quality Monitoring Data

    DTIC Science & Technology

    2012-08-01

    boundary of the lagoon is defined by the easternmost extent of maximum tidal influence, roughly 1.5 miles upstream. The Santa Margarita River feeding...occurring in the lagoon . The data describe a lagoon that was strongly dominated by its connection with tidal flow from the ocean. Daily fluctuations in water...decreasing freshwater flow, summertime heating, longer daylight hours, and a reduction in tidal flow as a result of natural berm building at the lagoon

  7. 33 CFR 117.600 - Lagoon Pond.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lagoon Pond. 117.600 Section 117.600 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon Pond...

  8. 33 CFR 117.600 - Lagoon Pond.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lagoon Pond. 117.600 Section 117.600 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon Pond...

  9. 33 CFR 117.600 - Lagoon Pond.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lagoon Pond. 117.600 Section 117.600 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon Pond...

  10. 33 CFR 117.600 - Lagoon Pond.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Lagoon Pond. 117.600 Section 117.600 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon Pond...

  11. 33 CFR 117.600 - Lagoon Pond.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lagoon Pond. 117.600 Section 117.600 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon Pond...

  12. Metagenomes of Mediterranean Coastal Lagoons

    PubMed Central

    Ghai, Rohit; Hernandez, Claudia Mella; Picazo, Antonio; Mizuno, Carolina Megumi; Ininbergs, Karolina; Díez, Beatriz; Valas, Ruben; DuPont, Christopher L.; McMahon, Katherine D.; Camacho, Antonio; Rodriguez-Valera, Francisco

    2012-01-01

    Coastal lagoons, both hypersaline and freshwater, are common, but still understudied ecosystems. We describe, for the first time, using high throughput sequencing, the extant microbiota of two large and representative Mediterranean coastal lagoons, the hypersaline Mar Menor, and the freshwater Albufera de Valencia, both located on the south eastern coast of Spain. We show there are considerable differences in the microbiota of both lagoons, in comparison to other marine and freshwater habitats. Importantly, a novel uncultured sulfur oxidizing Alphaproteobacteria was found to dominate bacterioplankton in the hypersaline Mar Menor. Also, in the latter prokaryotic cyanobacteria were almost exclusively comprised by Synechococcus and no Prochlorococcus was found. Remarkably, the microbial community in the freshwaters of the hypertrophic Albufera was completely in contrast to known freshwater systems, in that there was a near absence of well known and cosmopolitan groups of ultramicrobacteria namely Low GC Actinobacteria and the LD12 lineage of Alphaproteobacteria. PMID:22778901

  13. Metagenomes of Mediterranean coastal lagoons.

    PubMed

    Ghai, Rohit; Hernandez, Claudia Mella; Picazo, Antonio; Mizuno, Carolina Megumi; Ininbergs, Karolina; Díez, Beatriz; Valas, Ruben; DuPont, Christopher L; McMahon, Katherine D; Camacho, Antonio; Rodriguez-Valera, Francisco

    2012-01-01

    Coastal lagoons, both hypersaline and freshwater, are common, but still understudied ecosystems. We describe, for the first time, using high throughput sequencing, the extant microbiota of two large and representative Mediterranean coastal lagoons, the hypersaline Mar Menor, and the freshwater Albufera de Valencia, both located on the south eastern coast of Spain. We show there are considerable differences in the microbiota of both lagoons, in comparison to other marine and freshwater habitats. Importantly, a novel uncultured sulfur oxidizing Alphaproteobacteria was found to dominate bacterioplankton in the hypersaline Mar Menor. Also, in the latter prokaryotic cyanobacteria were almost exclusively comprised by Synechococcus and no Prochlorococcus was found. Remarkably, the microbial community in the freshwaters of the hypertrophic Albufera was completely in contrast to known freshwater systems, in that there was a near absence of well known and cosmopolitan groups of ultramicrobacteria namely Low GC Actinobacteria and the LD12 lineage of Alphaproteobacteria.

  14. Belowground dynamics in mangrove ecosystems

    USGS Publications Warehouse

    McKee, Karen L.

    2004-01-01

    Mangrove ecosystems are tropical/subtropical communities of primarily tree species that grow in the intertidal zone. These tidal communities are important coastal ecosystems that are valued for a variety of ecological and societal goods and services (fig. 1). Mangrove wetlands are important filters of materials moving between the land and sea, trapping sediment, nutrients, and pollutants in runoff from uplands and preventing their direct introduction into sensitive marine ecosystems such as seagrass beds and coral reefs. Mangroves serve as nursery grounds and refuge for a variety of organisms and are consequently vital to the biological productivity of coastal waters. Furthermore, because mangroves are highly resilient to disturbances such as hurricanes, they represent a self-sustaining, protective barrier for human populations living in the coastal zone. Mangrove ecosystems also contribute to shoreline stabilization through consolidation of unstable mineral sediments and peat formation. In order to help conserve mangrove ecoystems, scientists with the United States Geological Survey (USGS) at the National Wetlands Research Center are working to more fully understand the dynamics that impact these vital ecosystems.

  15. MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

    EPA Science Inventory

    Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

  16. MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

    EPA Science Inventory

    Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

  17. Modeling hurricane effects on mangrove ecosystems

    USGS Publications Warehouse

    Doyle, Thomas W.

    1997-01-01

    Mangrove ecosystems are at their most northern limit along the coastline of Florida and in isolated areas of the gulf coast in Louisiana and Texas. Mangroves are marine-based forests that have adapted to colonize and persist in salty intertidal waters. Three species of mangrove trees are common to the United States, black mangrove (Avicennia germinans), white mangrove (Laguncularia racemosa), and red mangrove (Rhizophora mangle). Mangroves are highly productive ecosystems and provide valuable habitat for fisheries and shorebirds. They are susceptible to lightning and hurricane disturbance, both of which occur frequently in south Florida. Climate change studies predict that, while these storms may not become more frequent, they may become more intense with warming sea temperatures. Sea-level rise alone has the potential for increasing the severity of storm surge, particularly in areas where coastal habitats and barrier shorelines are rapidly deteriorating. Given this possibility, U.S. Geological Survey researchers modeled the impact of hurricanes on south Florida mangrove communities.

  18. Ni cycling in mangrove sediments from New Caledonia

    NASA Astrophysics Data System (ADS)

    Noel, V. S.; Morin, G.; Juillot, F.; Marchand, C.; Brest, J.; Bargar, J.; Munoz, M.; Ardo, S.; Brown, G. E.

    2014-12-01

    In New Caledonia, mangroves receive large inputs of lateritic materials eroded from massive ultramafic deposits enriched in Fe, Ni, Mn, Cr, and Co. Because of the major physicochemical gradients, especially redox gradients, that characterize these ecosystems, mineralogical transformations may influence the crystal-chemistry and bioavailability of Ni and its mobility towards a lagoon of over 20,000 km2. Bulk and spatially resolved chemical analyses by SEM-EDXS were coupled with Ni K-edge X-ray absorption fine structure (XAFS) spectroscopy analysis to characterize the vertical and lateral changes in Ni speciation across the intertidal zone of a mangrove forest in the Vavouto Bay (New Caledonia) where Ni concentrations range from 1000 to 5300 mg•kg-1. XAFS results indicate that phyllosilicates and goethite inherited from the eroded lateritic materials are the dominant Ni-bearing phases in the surface horizons of the mangrove sediments. They are fully preserved at depth in the dry and oxic salt flat area, located on the inland side of the coast. In contrast, beneath the vegetated Rhizophoras and Avicennias stands Ni-bearing goethites rapidly diminish with increasing depth in the anoxic horizons of the sediments, and pyrite and organic complexes become the dominant Ni-containing species. Moreover, Ni incorporation in pyrite is more developed in the sediments beneath the intermediate Avicennia stand than beneath the Rhizophora stand that is closest to the shore. Such lateral changes in Ni speciation may be related to reoxidation of Ni-bearing pyrites in the Rhizophora stand, which is subject to periodic alternation of reducing and oxidizing events due to tidal fluctuations. These major changes in Ni speciation could significantly influence Ni mobility across the interidal zone. Indeed, as estimated with respect to Ti concentration, which is taken as a geochemical invariant, Ni is found to be immobile in the salt flat, to accumulate beneath the Avicennia stand, and to

  19. Metals in some lagoons of Mexico.

    PubMed

    Vazquez, F G; Sharma, V K; Alexander, V H; Frausto, C A

    1995-02-01

    The concentrations of metals, Cd, Cu, Fe, Mn, Ni, Pb, and Zn were determined in some lagoons to establish the level of metal pollution. The lagoons studied were Alvarado lagoon, Veracruz; San Andres lagoon, Tamaulipas; and Terminos lagoon, Campeche. The concentrations were determined in water, oyster (Crassostrea virginica), and sediments. Metals were accumulated in either oysters or sediments. Cu and Zn were higher in oysters and Fe and Mn were higher in sediments. The results in water samples were compared with the limit established by the Secretaria de Ecologia and Desarrollo Urbano Report and briefly discussed.

  20. Metals in some lagoons of Mexico.

    PubMed Central

    Vazquez, F G; Sharma, V K; Alexander, V H; Frausto, C A

    1995-01-01

    The concentrations of metals, Cd, Cu, Fe, Mn, Ni, Pb, and Zn were determined in some lagoons to establish the level of metal pollution. The lagoons studied were Alvarado lagoon, Veracruz; San Andres lagoon, Tamaulipas; and Terminos lagoon, Campeche. The concentrations were determined in water, oyster (Crassostrea virginica), and sediments. Metals were accumulated in either oysters or sediments. Cu and Zn were higher in oysters and Fe and Mn were higher in sediments. The results in water samples were compared with the limit established by the Secretaria de Ecologia and Desarrollo Urbano Report and briefly discussed. PMID:7621796

  1. Ecosystem carbon stocks of micronesian mangrove forests

    Treesearch

    J. Boone Kauffman; Chris Heider; Thomas G. Cole; Kathleen A. Dwire; Daniel C. Donato

    2011-01-01

    Among the least studied ecosystem services of mangroves is their value as global carbon (C) stocks. This is significant as mangroves are subject to rapid rates of deforestation and therefore could be significant sources of atmospheric emissions. Mangroves could be key ecosystems in strategies addressing the mitigation of climate change though reduced deforestation. We...

  2. Mangrove expansion and salt marsh decline at mangrove poleward limits.

    PubMed

    Saintilan, Neil; Wilson, Nicholas C; Rogers, Kerrylee; Rajkaran, Anusha; Krauss, Ken W

    2014-01-01

    Mangroves are species of halophytic intertidal trees and shrubs derived from tropical genera and are likely delimited in latitudinal range by varying sensitivity to cold. There is now sufficient evidence that mangrove species have proliferated at or near their poleward limits on at least five continents over the past half century, at the expense of salt marsh. Avicennia is the most cold-tolerant genus worldwide, and is the subject of most of the observed changes. Avicennia germinans has extended in range along the USA Atlantic coast and expanded into salt marsh as a consequence of lower frost frequency and intensity in the southern USA. The genus has also expanded into salt marsh at its southern limit in Peru, and on the Pacific coast of Mexico. Mangroves of several species have expanded in extent and replaced salt marsh where protected within mangrove reserves in Guangdong Province, China. In south-eastern Australia, the expansion of Avicennia marina into salt marshes is now well documented, and Rhizophora stylosa has extended its range southward, while showing strong population growth within estuaries along its southern limits in northern New South Wales. Avicennia marina has extended its range southwards in South Africa. The changes are consistent with the poleward extension of temperature thresholds coincident with sea-level rise, although the specific mechanism of range extension might be complicated by limitations on dispersal or other factors. The shift from salt marsh to mangrove dominance on subtropical and temperate shorelines has important implications for ecological structure, function, and global change adaptation.

  3. Use of deep water lagoons for reducing sewage toxicity prior to wastewater treatment

    SciTech Connect

    Shaw, J.R.; Zuiderveen, J.A.; Belcher, B.; McGinley, P.; Birge, W.J.

    1995-12-31

    Investigations were conducted to determine the effectiveness of deep lagoons as a means of minimizing toxicity and reducing wastewater parameters. A lagoon system associated with a wastewater treatment plant (WWTP) was selected for study and parameters identified for monitoring included toxicity, metal concentrations, total suspended solids (TSS) and ammonia. This system included two lagoons, with 7--15 day hydraulic retention times, which received municipal waste. Toxicity and other parameters were measured for raw influent water, the two lagoon outfalls, and the final WWTP effluent. In a definitive seven-day chronic test with Ceriodaphnia dubia, the NOEC of influent water was 20%, and the IC{sub 50} for reproduction was 22.3%. Outfall from the first deep water lagoon showed reduced toxicity. The NOEC and IC{sub 50} were 80 and 71.8%, respectively. Further reduction in toxicity occurred in the second lagoon. The NOEC was 80% and the IC{sub 50} was 75.9. The final effluent discharged from the treatment plant affected neither survival nor fecundity. A 7-day embryo larval test conducted with Pimephales promelas yielded similar results. NOEC values increased through the lagoon system and were 2.5, 40.0, 40.0 and 100%, respectively. Acute TIE procedures implicated both metals and ammonia as primary toxicants. In all tests a sequential reduction in toxicity was observed through the lagoons. Results of this investigation support the use of deep water lagoons as an effective and economical means of pretreating wastewater. This approach offers promise for municipal waters, industrial effluents and stormwater runoff.

  4. EXAFS analysis of iron cycling in mangrove sediments downstream a lateritized ultramafic watershed (Vavouto Bay, New Caledonia)

    NASA Astrophysics Data System (ADS)

    Noël, Vincent; Marchand, Cyril; Juillot, Farid; Ona-Nguema, Georges; Viollier, Eric; Marakovic, Gregory; Olivi, Luca; Delbes, Ludovic; Gelebart, Frédéric; Morin, Guillaume

    2014-07-01

    Mangrove forests are the dominant intertidal ecosystem of tropical coastlines. In New Caledonia, mangroves act as a buffer zone between massive Fe lateritic deposits and a lagoon partly registered by UNESCO as a World Heritage site. The New Caledonian mangroves are characterized by a botanical gradient composed of three main vegetal stands (i.e., Rhizophora spp., Avicennia marina and salt flat), which relies on the duration of tidal immersion that imposes gradients of pore-water salinity, oxygenation, and organic content in the sediment. In the present study, we have determined the distribution and speciation of Fe in mangrove sediments along this botanical gradient by using X-ray absorption spectroscopy (XAS) at the Fe K-edge. Both XANES and EXAFS results show that iron speciation strongly follows the redox boundaries marking the intertidal and depth zonations. Fe-bearing minerals eroded from lateritic outcrops, mainly goethite (α-FeOOH) and phyllosilicates (serpentine and talc), are the major Fe hosts in the upward horizons. These mineral species progressively disappear with increasing depth where pyrite (FeS2) forms, in the hydromorphic Rhizophora and Avicennia zones. Sulfate reduction is not observed in the drier salt flat zone. In addition to these reduction processes, intense re-oxidation of aqueous Fe(II) and pyrite leads to the formation of poorly ordered ferrihydrite, lepidocrocite (γ-FeOOH) and likely goethite in the upper sediments beneath Avicennia and Rhizophora stands. The relative proportion of the newly formed poorly ordered ferrihydrite and lepidocrocite is found to be higher in the Rhizophora mangrove stand, which is the closest to the shore. Tidal fluctuations may thus be a major cause for continuous Fe reduction-oxidation cycles in the vegetated mangrove stands, which could significantly affect the iron mass balance in mangrove systems.

  5. Prawn landings and their relationship with the extent of mangroves and shallow waters in western peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Loneragan, N. R.; Ahmad Adnan, N.; Connolly, R. M.; Manson, F. J.

    2005-04-01

    This study investigated changes in landings of all prawns, white prawns (mainly Penaeus merguiensis), mangrove extent, rainfall and the area of shallow water in western peninsular Malaysia. The most important state for both the landings of all prawns and white prawns was Perak where about 50% of all prawns and 35% of white prawns were landed. This is also the state with the largest, and most stable, extent of mangrove forest reserve (40 000 ha) and the largest area of shallow water (<5 m deep). Juvenile prawns from Perak may contribute to the landings of the nearby, adjacent states of Penang and Selangor, where the second highest landings for white prawns and total prawns, respectively, were found. The area of shallow water accounted for the greatest proportion of variation in landings of both all prawns and white prawns, and was the most significant variable fitted to multiple regressions of landings and coastal attributes (area of shallow water, mangrove area, length of coastline). Although there was a significant linear relationship between the landings of total prawns and mangrove area in both the 1980s and 1990s, this was not the case for the mangrove-dependent white prawns where a significant relationship was found only for the 1990s. Furthermore, landings of all prawns and white prawns in Selangor and Johor, where large losses of mangrove forest reserve have been recorded, appear to have been maintained or increased in the 1990s. The lack of a clear relationship between mangrove loss and prawn landings may be due to the migration of prawns from adjacent areas or that other attributes of mangroves, such as the length of mangrove-water interface, may be more important for the growth and survival of prawn populations than total area of mangroves.

  6. Effect of data pre-treatment procedures on principal component analysis: a case study for mangrove surface sediment datasets.

    PubMed

    Praveena, Sarva Mangala; Kwan, Ong Wei; Aris, Ahmad Zaharin

    2012-11-01

    Principal component analysis (PCA) is capable of handling large sets of data. However, lack of consistent method in data pre-treatment and its importance are the limitations in PCA applications. This study examined pre-treatments methods (log (x + 1) transformation, outlier removal, and granulometric and geochemical normalization) on dataset of Mengkabong Lagoon, Sabah, mangrove surface sediment at high and low tides. The study revealed that geochemical normalization using Al with outliers removal resulted in a better classification of the mangrove surface sediment than that outliers removal, granulometric normalization using clay and log (x + 1) transformation. PCA output using geochemical normalization with outliers removal demonstrated associations between environmental variables and tides of mangrove surface sediment, Mengkabong Lagoon, Sabah. The PCA outputs at high and low tides also provided to better interpret information about the sediment and its controlling factors in the intertidal zone. The study showed data pre-treatment method to be a useful procedure to standardize the datasets and reducing the influence of outliers.

  7. The reduction effects of mangrove forest on a tsunami based on field surveys at Pakarang Cape, Thailand and numerical analysis

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Hideaki; Koshimura, Shunichi; Goto, Kazuhisa; Miyagi, Toyohiko; Imamura, Fumihiko; Ruangrassamee, Anat; Tanavud, Charlchai

    2009-01-01

    Using an integrated approach including satellite imagery analysis, field measurements, and numerical modeling, we investigated the damage to mangroves caused by the 2004 Indian Ocean tsunami at Pakarang Cape in Pang Nga Province, Thailand. Comparing pre- and post-tsunami satellite imagery of the study area, we found that approximately 70% of the mangrove forest was destroyed by the tsunami. Based on field observations, we found that the survival rate of mangroves increased with increasing stem diameter. Specifically, we found that 72% of Rhizophora trees with a 25-30 cm stem diameter survived the tsunami impact, whereas only 19% with a 15-20 cm stem diameter survived. We simulated the 2004 Indian Ocean tsunami using the nonlinear shallow-water wave theory to reproduce the tsunami inundation flow and investigated the bending moment acting on the mangrove trees. Results of the numerical model showed that the tsunami inundated areas along the mangrove creeks, and its current velocity reached 5.0 m s -1. Based on the field measurements and numerical results, we proposed a fragility function for mangroves, which is the relationship between the probability of damage and the bending stress caused by the maximum bending moment. We refined the numerical model to include the damage probability of mangrove forests using the obtained fragility function to investigate the tsunami reduction effect of mangrove forest. Under simple numerical conditions related to the mangrove forest, ground level, and incident wave, the model showed that a mangrove forest of Rhizophora sp. with a density of 0.2 trees m -2 and a stem diameter of 15 cm in a 400 m wide area can reduce the tsunami inundation depth by 30% when the incident wave is assumed to have a 3.0 m inundation depth and a wave period of 30 min at the shoreline. However, 50% of the mangrove forest is destroyed by a 4.5 m tsunami inundation depth, and most of the mangrove forest is destroyed by a tsunami inundation depth greater

  8. Assessing confinement in coastal lagoons.

    PubMed

    Canu, Donata Melaku; Solidoro, Cosimo; Umgiesser, Georg; Cucco, Andrea; Ferrarin, Christian

    2012-11-01

    Measures of transport scale in aquatic systems can contribute to the formulation of definitions of indicators of the system's ecological properties. This paper addresses confinement, a specific transport scale proposed by biological scientists as a parameter that can capture and synthesize the principal properties that determine the spatial structure of biological communities in transitional environments. Currently, there is no direct experimental measure of confinement. In this study, a methodology based on the accumulation rate within a lagoon of a passive tracer of marine origin is proposed, the influences of different factors in the calculation of confinement are analyzed, and general recommendations are derived. In particular, we analyze the spatial and the temporal variability of confinement and its sensitivity to the seasonal variability of climatic forcing, the inputs from rivers and the parameterization of the tidal exchanges. The Lagoon of Venice is used as a case study. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Mangrove expansion and saltmarsh decline at mangrove poleward limits

    USGS Publications Warehouse

    Saintilan, Neil; Wilson, Nicholas C.; Rogers, Kerrylee; Rajkaran, Anusha; Krauss, Ken W.

    2014-01-01

    Mangroves are species of halophytic intertidal trees and shrubs derived from tropical genera and are likely delimited in latitudinal range by varying sensitivity to cold. There is now sufficient evidence that mangrove species have proliferated at or near their poleward limits on at least five continents over the past half century, at the expense of salt marsh. Avicennia is the most cold-tolerant genus worldwide, and is the subject of most of the observed changes. Avicennia germinans has extended in range along the US Atlantic coast and expanded into salt marsh as a consequence of lower frost frequency and intensity in the southern USA. The genus has also expanded into salt marsh at its southern limit in Peru, and on the Pacific coast of Mexico. Mangroves of several species have expanded in extent and replaced salt marsh where protected within mangrove reserves in Guangdong Province. In south-eastern Australia, the expansion of Avicennia marina into salt marshes is now well documented, and Rhizophora stylosa has extended its range southward, while showing strong population growth within estuaries along its southern limits in northern New South Wales. Avicennia marina has extended its range southwards in South Africa. The changes are consistent with the pole-ward extension of temperature thresholds co-incident with sea-level rise, although the specific mechanism of range extension might be complicated by limitations on dispersal or other factors. The shift from salt marsh to mangrove dominance on subtropical and temperate shorelines has important implications for ecological structure, function, and global change adaptation.

  10. Sludge storage lagoon biogas recovery and use

    SciTech Connect

    Muller, D.; Norville, C. )

    1991-07-01

    The City of Memphis has two wastewater treatment plants. The SWTP employs two large anaerobic digestion sludge lagoons as part of the overall sludge treatment system. Although these lagoons are effective in concentrating and digesting sludge, they can generate offensive odors. The SWTP uses aerobic digesters to partially stabilize the sludge and help reduce objectionable odors before it enters the lagoons. The anaerobic digestion of sludge in the lagoons results in the dispersion of a large quantity of biogas into the atmosphere. The City realized that if the lagoons could be covered, the odor problem could be resolved, and at the same, time, biogas could be recovered and utilized as a source of energy. In 1987, the City commissioned ADI International to conduct a feasibility study to evaluate alternative methods of covering the lagoons and recovering and utilizing the biogas. The study recommended that the project be developed in two phases: (1) recovery of the biogas and (2) utilization of the biogas. Phase 1 consists of covering the two lagoons with an insulated membrane to control odor and temperature and collect the biogas. Phase 1 was found to be economically feasible and offered a unique opportunity for the City to save substantial operating costs at the treatment facility. The Memphis biogas recovery project is the only application in the world where a membrane cover has been used on a municipal wastewater sludge lagoon. It is also the largest lagoon cover system in the world.

  11. Can mangrove plantation enhance the functional diversity of macrobenthic community in polluted mangroves?

    PubMed

    Leung, Jonathan Y S; Cheung, Napo K M

    2017-03-15

    Mangrove plantation is widely applied to re-establish the plant community in degraded mangroves, but its effectiveness to restore the ecological functions of macrobenthic community remains poorly known, especially when pollution may overwhelm its potential positive effect. Here, we tested the effect of mangrove plantation on the ecological functions of macrobenthic community in a polluted mangrove by analyzing biological traits of macrobenthos and calculating functional diversity. Mangrove plantation was shown to enhance the functional diversity and restore the ecological functions of macrobenthic community, depending on seasonality. Given the polluted sediment, however, typical traits of opportunistic species (e.g. small and short-lived) prevailed in all habitats and sampling times. We conclude that mangrove plantation can help diversify the ecological functions of macrobenthic community, but its effectiveness is likely reduced by pollution. From the management perspective, therefore, pollution sources must be stringently regulated and mangrove plantation should be conducted to fully recover degraded mangroves.

  12. Environmental tolerances of rare and common mangroves along light and salinity gradients.

    PubMed

    Dangremond, Emily M; Feller, Ilka C; Sousa, Wayne P

    2015-12-01

    Although mangroves possess a variety of morphological and physiological adaptations for life in a stressful habitat, interspecific differences in survival and growth under different environmental conditions can shape their local and geographic distributions. Soil salinity and light are known to affect mangrove performance, often in an interactive fashion. It has also been hypothesized that mangroves are intrinsically shade intolerant due to the high physiological cost of coping with saline flooded soils. To evaluate the relationship between stress tolerance and species distributions, we compared responses of seedlings of three widespread mangrove species and one narrow endemic mangrove species in a factorial array of light levels and soil salinities in an outdoor laboratory experiment. The more narrowly distributed species was expected to exhibit a lower tolerance of potentially stressful conditions. Two of the widespread species, Avicennia germinans and Lumnitzera racemosa, survived and grew well at low-medium salinity, regardless of light level, but performed poorly at high salinity, particularly under high light. The third widespread species, Rhizophora mangle, responded less to variation in light and salinity. However, at high salinity, its relative growth rate was low at every light level and none of these plants flushed leaves. As predicted, the rare species, Pelliciera rhizophorae, was the most sensitive to environmental stressors, suffering especially high mortality and reduced growth and quantum yield under the combined conditions of high light and medium-high salinity. That it only thrives under shaded conditions represents an important exception to the prevailing belief that halophytes are intrinsically constrained to be shade intolerant.

  13. Coastal Landforms and Accumulation of Mangrove Peat Increase Carbon Sequestration and Storage

    NASA Astrophysics Data System (ADS)

    Costa, M. T.; Excurra, P.; Ezcurra, E.; Garcillan, P. P.; Aburto-Oropeza, O.

    2016-02-01

    Many studies have highlighted the considerable belowground carbon storage of mangroves and other coastal ecosystems (as much 30% of total ocean carbon storage). Mangroves are among the most carbon-rich forests in the tropics, containing on average more than 1,000 Mg C/ha. We sampled mangrove sediments in four locations along the Pacific Coast of Mexico, from the Baja California Sur in the north to Chiapas near the Guatemalan boarder. These sites varied in their coastal geomorphology and rainfall regimes. The mangroves of rainy Chiapas possessed the deepest and most carbon-rich Rhizophora peat deposits of any of the sites (in places more than 2,000 Mg/ha). More surprisingly, in Balandra, one of the desert mangrove lagoons of Baja California Sur, the Avicennia-dominated mudflat zone of the forest possessed deep and rich peat deposits, ranging from 400-1,300 Mg/ha. This forest, hemmed in by relatively steep hillsides demonstrates the potential for mangroves to accrete carbon-rich peat vertically when local topography precludes their landwards expansion with sea-level rise. Our microscopic examination of root fibers from these peat deposits revealed the importance of Avicennia to the formation of buried organic matter deposits. We used 14C dating to track the age of the Baja California deposits, whose ages ranged between 1193 and 1636 BP. Plotting the calibrated 14C age of each peat sample from Balandra against the depth of the sample below the mean sea-level, we found a very significant linear trend (r2 = 0.87, P < 0.0001) with a slope of 0.070 ±0.007 mm/yr. Belowground carbon sequestration rates during recent decades varied from very low (ca. 0.1 Mg.ha-1.yr-1) in a receding fringe in Bahía Magdalena or a halophilic hinterland in Balandra, to 9-20 Mg.ha-1.yr-1 in a Rhizophora mudflat in La Encrucijada. With only 0.49% of the total area, the mangroves around the Gulf of California store 18% of the total belowground carbon pool of the whole region, 76 Tg in total.

  14. Impacts of exotic mangroves and mangrove control on tide pool fish assemblages

    Treesearch

    Richard A. MacKenzie; Cailtin L. Kryss

    2013-01-01

    Fish were sampled from tide pools in Hawaii to determine how exotic mangroves Rhizophora mangle and the use of herbicides to chemically eradicate them are impacting tide pool fish assemblages. Ecological parameters were compared among mangrove-invaded, native vegetated, and non-vegetated tide pools before and after mangroves had been chemically...

  15. Economic valuation of a mangrove ecosystem threatened by shrimp aquaculture in Sri Lanka.

    PubMed

    Gunawardena, M; Rowan, J S

    2005-10-01

    Mangrove ecosystems in Sri Lanka are increasingly under threat from development projects, especially aquaculture. An economic assessment is presented for a relatively large (42 ha) shrimp culture development proposed for the Rekawa Lagoon system in the south of Sri Lanka, which involved an extended cost-benefit analysis of the proposal and an estimate of the "total economic value" (TEV) of a mangrove ecosystem. The analysis revealed that the internal benefits of developing the shrimp farm are higher than the internal costs in the ratio of 1.5:1. However, when the wider environmental impacts are more comprehensively evaluated, the external benefits are much lower than the external costs in a ratio that ranges between 1:6 and 1:11. In areas like Rekawa, where agriculture and fisheries are widely practiced at subsistence levels, shrimp aquaculture developments have disproportionately large impacts on traditional livelihoods and social welfare. Thus, although the analysis retains considerable uncertainties, more explicit costing of the environmental services provided by mangrove ecosystems demonstrates that low intensity, but sustainable, harvesting has far greater long-term value to local stakeholders and the wider community than large shrimp aquaculture developments.

  16. Habitat and host specificity of trematode metacercariae in fiddler crabs from mangrove habitats in Florida.

    PubMed

    Smith, Nancy F; Ruiz, Gregory M; Reed, Sherry A

    2007-10-01

    Fiddler crabs (Uca spp.) are common inhabitants of temperate and tropical coastal communities throughout the world, often occupying specific microenvironments within mangrove and salt marsh habitats. As second intermediate hosts for trematodes, we investigated patterns of host distribution and parasitism for 3 species of sympatric fiddler crabs in mangrove habitats adjacent to the Indian River Lagoon, Florida. Fiddler crab distribution varied among species, with Uca speciosa dominating the low and mid intertidal regions of mangrove banks. This species also exhibited higher prevalence and abundance of Probolocoryphe lanceolata metacercariae compared with Uca rapax, which is relatively more abundant in the high intertidal zone. We conducted a field experiment to test whether U. speciosa was more heavily parasitized by P. lanceolata as a result of its habitat distribution by raising U. speciosa and U. rapax under identical environmental conditions. After exposure to shedding cercariae under the same field conditions, all individuals of U. speciosa became parasitized by P. lanceolata, whereas no U. rapax were parasitized, suggesting that differences in parasitism were driven by host selection.

  17. Restoration of biogeochemical function in mangrove forests

    USGS Publications Warehouse

    McKee, K.L.; Faulkner, P.L.

    2000-01-01

    Forest structure of mangrove restoration sites (6 and 14 years old) at two locations (Henderson Creek [HC] and Windstar [WS]) in southwest Florida differed from that of mixed-basin forests (>50 years old) with which they were once contiguous. However, the younger site (HC) was typical of natural, developing forests, whereas the older site (WS) was less well developed with low structural complexity. More stressful physicochemical conditions resulting from incomplete tidal flushing (elevated salinity) and variable topography (waterlogging) apparently affected plant survival and growth at the WS restoration site. Lower leaf fall and root production rates at the WS restoration site, compared with that at HC were partly attributable to differences in hydroedaphic conditions and structural development. However, leaf and root inputs at each restoration site were not significantly different from that in reference forests within the same physiographic setting. Macrofaunal consumption of tethered leaves also did not differ with site history, but was dramatically higher at HC compared with WS, reflecting local variation in leaf litter processing rates, primarily by snails (Melampus coffeus). Degradation of leaves and roots in mesh bags was slow overall at restoration sites, however, particularly at WS where aerobic decomposition may have been more limited. These findings indicate that local or regional factors such as salinity regime act together with site history to control primary production and turnover rates of organic matter in restoration sites. Species differences in senescent leaf nitrogen content and degradation rates further suggest that restoration sites dominated by Laguncularia racemosa and Rhizophora mangle should exhibit slower recycling of nutrients compared with natural basin forests where Avicennia germinans is more abundant. Structural development and biogeochemical functioning of restored mangrove forests thus depend on a number of factors, but site

  18. Global change impacts on mangrove ecosystems

    USGS Publications Warehouse

    McKee, Karen L.

    2004-01-01

    Mangroves are tropical/subtropical communities of primarily tree species that grow in the intertidal zone. These tidal forests are important coastal ecosystems that are valued for a variety of ecological and societal goods and services. Major local threats to mangrove ecosystems worldwide include clearcutting and trimming of forests for urban, agricultural, or industrial expansion; hydrological alterations; toxic chemical spills; and eutrophication. In many countries with mangroves, much of the human population resides in the coastal zone, and their activities often negatively impact the integrity of mangrove forests. In addition, eutrophication, which is the process whereby nutrients build up to higher than normal levels in a natural system, is possibly one of the most serious threats to mangroves and associated ecosystems such as coral reefs. Scientists with the U.S. Geological Survey (USGS) at the National Wetlands Research Center are working to more fully understand global impacts on these significant ecosystems.Changes in climate and other factors may also affect mangroves, but in complex ways. Global warming may promote expansion of mangrove forests to higher latitudes and accelerate sea-level rise through melting of polar ice or steric expansion of oceans. Changes in sea level would alter flooding patterns and the structure and areal extent of mangroves. Climate change may also alter rainfall patterns, which would in turn change local salinity regimes and competitive interactions of mangroves with other wetland species. Increases in frequency or intensity of tropical storms and hurricanes in combination with sea-level rise may alter erosion and sedimentation rates in mangrove forests. Another global change factor that may directly affect mangrove growth is increased atmospheric carbon dioxide (CO2), caused by burning of fossil fuels and other factors. Elevated CO2 concentration may increase mangrove growth by stimulating photosynthesis or improving water use

  19. Denitrification enzyme activity in swine wastewater lagoons

    USDA-ARS?s Scientific Manuscript database

    Anaerobic lagoons are typically used for treatment of swine wastewater. Although these anaerobic lagoons were once thought to be relatively simple in their physical, chemical, and biological processes, they are actually very sophisticated. Recent reports of high levels of di-nitrogen emissions and h...

  20. Recent advances in understanding Colombian mangroves

    NASA Astrophysics Data System (ADS)

    Polanía, J.; Urrego, L. E.; Agudelo, C. M.

    2015-02-01

    Throughout the last 15 years, researchers at the National University of Colombia at Medellin have studied Colombian mangroves. Remote sensing, pollen analysis of superficial and deep sediments, Holocene coastal vegetation dynamics, sediment dating using 14C and 210Pb, sampling in temporary plots, sampling in temporary and permanent plots, and other techniques have been applied to elucidate long- and short-term mangrove community dynamics. The studied root fouling community is structured by several regulatory mechanisms; habitat heterogeneity increases species richness and abundance. Fringe mangroves were related to Ca concentration in the soil and the increased dominance of Laguncularia racemosa and other nonmangrove tree species, while the riverine mangroves were associated with Mg concentration and the dominance of Rhizophora mangle. The seedling and mangrove tree distributions are determined by a complex gradient of natural and anthropogenic disturbances. Mangrove pollen from surface sediments and the existing vegetation and geomorphology are close interrelated. Plant pollen of mangrove and salt marsh reflects environmental and disturbance conditions, and also reveals forest types. Forest dynamics in both coasts and their sensitivity of to anthropogenic processes are well documented in the Late Quaternary fossil record. Our studies of short and long term allow us to predict the dynamics of mangroves under different scenarios of climate change and anthropogenic stress factors that are operating in Colombian coasts. Future research arises from these results on mangrove forests dynamics, sea-level rise at a fine scale using palynology, conservation biology, and carbon dynamics.

  1. Coastal sediment elevation change following anthropogenic mangrove clearing

    NASA Astrophysics Data System (ADS)

    Hayden, Heather L.; Granek, Elise F.

    2015-11-01

    Coastal mangrove forests along tropical shorelines serve as an important interface between land and sea. They provide a physical buffer protecting the coastline from erosion and act as sediment "traps" catching terrestrial sediment, thus preventing smothering of subtidal coral reefs. Coastal development that removes mangrove habitat may impact adjacent nearshore coral reefs through sedimentation and nutrient loading. We examined differences in sediment elevation change between patches of open-coast intact and anthropogenically cleared red mangroves (Rhizophora mangle) on the east side of Turneffe Atoll, Belize, to quantify changes following mangrove clearing. Samples were collected over a 24 month period at five study sites, each containing paired intact (+mangrove) and cleared (-mangrove) plots. Five sediment elevation pins were deployed in each plot: behind areas cleared of mangroves (-mangrove) and behind adjacent intact mangroves (+mangrove). Sediment elevation increased at intact mangrove sites (M = +3.83 mm, SE = 0.95) whereas cleared mangrove areas suffered elevation loss (M = -7.30 mm, SE = 3.38). Mangroves inshore of partial or continuous gaps in the adjacent fringing reefs had higher rates of elevation loss (M = -15.05 mm) than mangroves inshore of continuous fringing reefs (M = -1.90 mm). Our findings provide information on potential effects of mangrove clearing and the role of offshore habitat characteristics on coastal sediment trapping and maintenance of sediment elevation by mangroves. With implications for coastline capacity to adjust to sea level rise, these findings are relevant to management of coastal fringing mangrove forests across the Caribbean.

  2. Secondary production of the fiddler crab Uca rapax from mangrove areas under anthropogenic eutrophication in the Western Atlantic, Brazil.

    PubMed

    Costa, Tarso de M M; Soares-Gomes, Abilio

    2015-12-30

    Fiddler crabs Uca rapax were analyzed in three mangrove areas located in both a lagoon and estuarine system in order to study the influence of eutrophication on their population dynamics and production. Populations at the three sites showed a biased sex ratio. Densities were similar at the three sites, but biomass was higher at the lagoon system. Despite biomass being higher at the most eutrophic site, this site exhibited the lowest production. Regarding age structure, the population inhabiting the less eutrophic site mainly comprised younger crabs. The lower production and smaller P/B ratio found in the more eutrophic site were most likely consequences of a high mortality rate and an aged population. Our study evidences the high plasticity of the fiddler crab U. rapax, and confirms secondary production and P/B ratio estimates as useful tools to assess the effects of environmental change. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Osmotic and hydraulic adjustment of mangrove saplings to extreme salinity.

    PubMed

    Méndez-Alonzo, Rodrigo; López-Portillo, Jorge; Moctezuma, Coral; Bartlett, Megan K; Sack, Lawren

    2016-12-01

    Salinity tolerance in plant species varies widely due to adaptation and acclimation processes at the cellular and whole-plant scales. In mangroves, extreme substrate salinity induces hydraulic failure and ion excess toxicity and reduces growth and survival, thus suggesting a potentially critical role for physiological acclimation to salinity. We tested the hypothesis that osmotic adjustment, a key type of plasticity that mitigates salinity shock, would take place in coordination with declines in whole-plant hydraulic conductance in a common garden experiment using saplings of three mangrove species with different salinity tolerances (Avicennia germinans L., Rhizophora mangle L. and Laguncularia racemosa (L.) C.F. Gaertn., ordered from higher to lower salinity tolerance). For each mangrove species, four salinity treatments (1, 10, 30 and 50 practical salinity units) were established and the time trajectories were determined for leaf osmotic potential (Ψs), stomatal conductance (gs), whole-plant hydraulic conductance (Kplant) and predawn disequilibrium between xylem and substrate water potentials (Ψpdd). We expected that, for all three species, salinity increments would result in coordinated declines in Ψs, gs and Kplant, and that the Ψpdd would increase with substrate salinity and time of exposure. In concordance with our predictions, reductions in substrate water potential promoted a coordinated decline in Ψs, gs and Kplant, whereas the Ψpdd increased substantially during the first 4 days but dissipated after 7 days, indicating a time lag for equilibration after a change in substratum salinity. Our results show that mangroves confront and partially ameliorate acute salinity stress via simultaneous reductions in Ψs, gs and Kplant, thus developing synergistic physiological responses at the cell and whole-plant scales. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Aerated Lagoons. Student Manual. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Andersen, Lorri

    This student manual contains the textual material for a unit which focuses on the structural and operationally unique features of aerated lagoons. Topic areas discussed include: (1) characteristics of completely mixed aerated lagoons; (2) facultative aerated lagoons; (3) aerated oxidation ponds; (4) effects of temperature on aerated lagoons; (5)…

  5. High performance aerated lagoon systems

    SciTech Connect

    Rich, L.

    1999-08-01

    At a time when less money is available for wastewater treatment facilities and there is increased competition for the local tax dollar, regulatory agencies are enforcing stricter effluent limits on treatment discharges. A solution for both municipalities and industry is to use aerated lagoon systems designed to meet these limits. This monograph, prepared by a recognized expert in the field, provides methods for the rational design of a wide variety of high-performance aerated lagoon systems. Such systems range from those that can be depended upon to meet secondary treatment standards alone to those that, with the inclusion of intermittent sand filters or elements of sequenced biological reactor (SBR) technology, can also provide for nitrification and nutrient removal. Considerable emphasis is placed on the use of appropriate performance parameters, and an entire chapter is devoted to diagnosing performance failures. Contents include: principles of microbiological processes, control of algae, benthal stabilization, design for CBOD removal, design for nitrification and denitrification in suspended-growth systems, design for nitrification in attached-growth systems, phosphorus removal, diagnosing performance.

  6. [Analysis of typical mangrove spectral reflectance characteristics].

    PubMed

    Yu, Xiang; Zhang, Feng-Shou; Liu, Qing; Li, De-Yi; Zhao, Dong-Zhi

    2013-02-01

    Acquisition of mangrove spectrum properties and detecting the sensitive bands provide technology basis for inverse modeling and estimation by remote sensing for various indexes of mangrove. The typical mangroves of Guangxi Shankou Mangrove Reserve were taken for study objects, the standard spectrum curves of Bruguiera gymnorrhiza (Linn.) Savigny, Rhizophora stylosa, Kandelia candel, Avicennia marina, Aegiceras corniculatum, Spartina anglica and mudflat were gained by denoising analysis of field-measured spectrum curves acquired by ASD FieldSpec 2. Analyzing the spectral characteristics and their differences, the authors found that the spectrum curves for various kinds of mangrove are coincident, the bands that appeared with reflection peaks and reflection valleys are basically identical, the within-class differentiated characteristics are comparatively small, the spectrum characteristics of mangroves are obviously different with Spartina anglica and mudflat. In order to gain the quantitative description for within-class differentiated characteristics of mangrove, space distance method, correlation coefficient method and spectral angle mapping method were used to calculate the within-class differentiated characteristics. The division accuracy of correlation coefficient method is higher than spectral angle mapping method which is higher than space distance method, and the result indicates that the spectrum differences of within-class mangrove and Spartina anglica are relatively small with correlation coefficients more than 0.995, and spectrum curve angle cosine values more than 0.95.

  7. Mangroves of the Pacific Islands: research opportunities

    Treesearch

    Ariel E. Lugo

    1990-01-01

    The perception of mangroves by people in the Pacific islands and throughout all the world has changed in the past decades. Today, the economic, social, ecologic, and esthetic values of mangroves are well recognized. Past research on these ecosystems is responsible for the change in perception. However, a review of eleven subjects relevant to the management of Pacific...

  8. The Distribution of Ammonia-Oxidizing Betaproteobacteria in Stands of Black Mangroves (Avicennia germinans).

    PubMed

    Laanbroek, Hendrikus J; Keijzer, Rosalinde M; Verhoeven, Jos T A; Whigham, Dennis F

    2012-01-01

    The distribution of species of aerobic chemolitho-autotrophic microorganisms such as ammonia-oxidizing bacteria are governed by pH, salinity, and temperature as well as the availability of oxygen, ammonium, carbon dioxide, and other inorganic elements required for growth. Impounded mangrove forests in the Indian River Lagoon, a coastal estuary on the east coast of Florida, are dominated by mangroves, especially stands of Black mangrove (Avicennia germinans) that differ in the size and density of individual plants. In March 2009, the management of one impoundment was changed to a regime of pumping estuarine water into the impoundment at critical times of the year to eliminate breeding sites for noxious insects. We collected soil samples in three different Black mangrove habitats before and after the change in management to determine the impacts of the altered hydrologic regimes on the distribution of 16s rRNA genes belonging to ammonia-oxidizing betaproteobacteria (β-AOB). We also sampled soils in an adjacent impoundment in which there had not been any hydrologic alteration. At the level of 97% mutual similarity in the 16s rRNA gene, 13 different operational taxonomic units were identified; the majority related to the lineages of Nitrosomonas marina (45% of the total clones), Nitrosomonas sp. Nm143 (23%), and Nitrosospira cluster 1 (19%). Long-term summer flooding of the impoundment in 2009, after initiation of the pumping regime, reduced the percentage of N. marina by half between 2008 and 2010 in favor of the two other major lineages and the potential ammonia-oxidizing activity decreased by an average of 73%. Higher interstitial salinities, probably due to a prolonged winter drought, had a significant effect on the composition of the β-AOB in March 2009 compared to March 2008: Nitrosomonas sp. Nm143 was replaced by Nitrosospira cluster 1 as the second most important lineage. There were small, but significant differences in the bacterial communities between the

  9. The Distribution of Ammonia-Oxidizing Betaproteobacteria in Stands of Black Mangroves (Avicennia germinans)

    PubMed Central

    Laanbroek, Hendrikus J.; Keijzer, Rosalinde M.; Verhoeven, Jos T. A.; Whigham, Dennis F.

    2012-01-01

    The distribution of species of aerobic chemolitho-autotrophic microorganisms such as ammonia-oxidizing bacteria are governed by pH, salinity, and temperature as well as the availability of oxygen, ammonium, carbon dioxide, and other inorganic elements required for growth. Impounded mangrove forests in the Indian River Lagoon, a coastal estuary on the east coast of Florida, are dominated by mangroves, especially stands of Black mangrove (Avicennia germinans) that differ in the size and density of individual plants. In March 2009, the management of one impoundment was changed to a regime of pumping estuarine water into the impoundment at critical times of the year to eliminate breeding sites for noxious insects. We collected soil samples in three different Black mangrove habitats before and after the change in management to determine the impacts of the altered hydrologic regimes on the distribution of 16s rRNA genes belonging to ammonia-oxidizing betaproteobacteria (β-AOB). We also sampled soils in an adjacent impoundment in which there had not been any hydrologic alteration. At the level of 97% mutual similarity in the 16s rRNA gene, 13 different operational taxonomic units were identified; the majority related to the lineages of Nitrosomonas marina (45% of the total clones), Nitrosomonas sp. Nm143 (23%), and Nitrosospira cluster 1 (19%). Long-term summer flooding of the impoundment in 2009, after initiation of the pumping regime, reduced the percentage of N. marina by half between 2008 and 2010 in favor of the two other major lineages and the potential ammonia-oxidizing activity decreased by an average of 73%. Higher interstitial salinities, probably due to a prolonged winter drought, had a significant effect on the composition of the β-AOB in March 2009 compared to March 2008: Nitrosomonas sp. Nm143 was replaced by Nitrosospira cluster 1 as the second most important lineage. There were small, but significant differences in the bacterial communities between the

  10. Movement of lagoon-liquor constituents below four animal-waste lagoons.

    PubMed

    DeSutter, Tom M; Pierzynski, Gary M; Ham, Jay M

    2005-01-01

    Movement of liquor constituents from animal-waste lagoons has the potential to degrade ground water quality. The depth of movement and concentrations of lagoon-liquor constituents in the soil underlying three cattle (Bos taurus)-waste retention lagoons and one swine (Sus scrofa)-waste lagoon were determined. Samples were taken by using a direct-push coring machine, dissected by depth, and analyzed for total N, organic C, CaCO3, pH, cation exchange capacity (CEC), texture, and extractable NO3, NH(4), P, Cl, Ca, Mg, K, and Na. Ammonium N concentrations were greatest in the upper 0.5 m of soil under all four lagoons with concentrations ranging from 94 to 1139 mg kg(-1). Organic N was determined to make up between 39 and 74% of the total N beneath all lagoons. The swine lagoon had 2.4 kg N m(-2) in the underlying soil whereas the cattle lagoon with highest quantity of N had 1.2 kg N m(-2) in the underlying soil. Although N concentrations decreased with depth, N was greater than expected background levels at the bottom of some cores, indicating that the sampling efforts did not reach the bottom of the N plume. Nitrate N concentrations were generally less than 5 mg kg(-1) immediately below the lagoon floor. In the uppermost 0.5 m of soil underlying the swine and three cattle lagoons, NH4+ occupied 44% and between 1 and 22% of the soil cation exchange sites, respectively. The depth of movement of N under these lagoons, as much as 4 m, may pose remediation difficulties at lagoon closure.

  11. [Costa Rica mangroves: the north Pacific].

    PubMed

    Zamora-Trejos, Priscilla; Cortés, Jorge

    2009-09-01

    Costa Rica has mangrove forests on both the Caribbean and Pacific coasts. The Pacific side has 99% of the mangrove area of the country. In this review we compile available information on the mangroves of the north Pacific coast of Costa Rica, from Bahía Salinas, on the border with Nicaragua, to the tip of the Peninsula de Nicoya at Cabo Blanco. We provide information on the location of the mangroves and all available information for each mangrove forest. These mangrove communities are smaller in extension and tree sizes, and have lower diversity compared to the mangroves on the southern section of the Pacific coast of Costa Rica. The dominant species are Rhizophora mangle and Rhizophora racemosa along the canal edges, backed by Avicennia germinans, and farther inland Avicennia bicolor, Laguncularia racemosa and Conocarpus erectus. At Potrero Grande a healthy population of Pelliciera rhizophorae, a rare species, has been reported. We recognized 38 mangrove communities in this part of the country, based on the National Wetland Inventory, published papers, field observations, theses, technical reports, and the national topographic maps (1:50,000, Instituto Geográfico Nacional). Relatively detailed information could be found for only five mangrove forests, for 14 more only prelimary and incomplete lists of plants and in some cases of animal species are available, for nine there is even less information, and for nine more only their location is known, which in some cases was not correct. Detail mapping, characterization of the vegetation and fauna, physiological studies, analyses of biogeochemical and physical processes, economic valuations, and determination of the health status of the mangrove of the northern Pacific coast, as well as for the rest of Costa Rica, are neccesary and urgent.

  12. [Current status of mangrove germplasm resources and key techniques for mangrove seedling propagation in China].

    PubMed

    Hu, Hong-You; Chen, Shun-Yang; Wang, Wen-Qing; Dong, Ke-Zuan; Lin, Guang-Hui

    2012-04-01

    Mangrove germplasm and nursery operation are the foundations of all mangrove ecological restoration projects. Based on the existing literatures and our own experiences, and by using cluster analysis and other methods, this paper assessed the current status of the mangrove germplasm resources and the key techniques for mangrove seedlings propagation in China. In China, the mangrove communities could be divided into 4 types, including low temperature tolerant widespread type, widespread type, thermophilic widespread type, and tropical type, and the mangrove distribution sites could be divided into 5 regions, i. e., eastern Hainan coast, Beibuwan Gulf coast, Pearl River estuary and eastern Guangdong coast, southern Fujian and Taiwan coast, and eastern Fujian and southern Zhejiang coast. The mangroves in Beibuwan Gulf coast region took up 75.3% of the total mangrove germplasm resources in the country. At present, the percentage of the mangrove species applied for seedling propagation in China was estimated at 52.6%, most of which were of viviparous species. The six key steps in mangrove nursery operation included the selection of proper seedling propagation methods, the collection and storage of seeds or propagules, the ways of raising seedlings, the management of water and salinity, the control of diseases and pests, and the prevention of cold damage during winter. The structure, functions, and applieations of the present five types of mangrove nurseries, including dry land nursery, mangrove tidal nursery, mudflat nursery, Jiwei pond nursery, and Spartina mudflat nursery, were also analyzed, which could provide guidance for the integrated management of mangrove ecological restoration engineering.

  13. Occurrence of species-rich crab fauna in a human-impacted mangrove forest questions the application of community analysis as an environmental assessment tool

    NASA Astrophysics Data System (ADS)

    Geist, Simon Joscha; Nordhaus, Inga; Hinrichs, Saskia

    2012-01-01

    Diversity and composition of the intertidal brachyuran crab community in the Segara Anakan Lagoon (SAL), Java, Indonesia, during the dry season of 2005 and the rainy season of 2006, shows that crab community composition and structure alone appeared to be poor indicators for the state of a forest in terms of tree diversity and wood-cutting intensity. The lagoon is surrounded by the largest mangrove stand in Java and is under constant anthropogenic pressure, mainly due to logging, land conversion for agriculture, overfishing and industrial pollution. This study aims to determine the crab community composition at different sites of the lagoon in relation to vegetation composition and sediment parameters. In addition it investigates if mangrove crabs can be used as bioindicators to describe the environmental state of mangrove forests (tree diversity, degree of logging). It was assumed to find a low crab diversity and species richness and a strong dominance of a single species at highly disturbed forest sites compared to moderately disturbed sites. A stratified, hierarchical design was used to sample the crab fauna at 13 stations distributed over the entire lagoon. Additionally, abiotic parameters and vegetation composition were recorded. In total 6463 crabs were caught belonging to 49 species, 5 superfamilies and 10 families, with Ocypodidae and Sesarmidae being the families of most note. Mean density of adult crabs was 27.7 individuals*m -2 and mean biomass was 12.8 g wet mass*m -2 or 1.3 g ash free dry mass*m -2. Density and biomass varied strongly within and between stations but they where within the range reported for other mangrove forests of the Indo-West-Pacific. Species composition was significantly different between stations. The distribution of facultatively leaf-feeding grapsid crabs was related to vegetation parameters (tree, seedling and undergrowth density), but the occurrence of single crab and tree species was not correlated. The distribution of

  14. Preliminary assessment of post-Haiyan mangrove damage and short-term recovery in Eastern Samar, central Philippines.

    PubMed

    Primavera, J H; Dela Cruz, M; Montilijao, C; Consunji, H; Dela Paz, M; Rollon, R N; Maranan, K; Samson, M S; Blanco, A

    2016-08-30

    Strong winds and storm surges from Typhoon Haiyan caused damage of US$12-15billion and >10,000 human casualties in central Philippines in November 2013. To validate a proposed government US$22million mangrove replanting program, mangrove damage and short-term recovery were surveyed in seven natural and planted mangrove sites in Eastern Samar province at 2.5month and 4.5month post-Haiyan. The preliminary assessment showed that natural mangroves (except for those directly hit by the storm) were recovering by means of tree sprouts and surviving seedlings and saplings compared to the devastated plantation. Likewise, tree mortality was higher in the plantation and natural forests hit by the storm surge, compared to more undamaged and partially damaged trees in natural mangroves. Hence the main recommendations to government are (1) to protect recovering mangroves by not releasing rehabilitation funds (that will inadvertently pay for clearing of live trees and for removal of seedlings), (2) to only plant in totally damaged sites (e.g., plantations), and (3) to only plant naturally dominant species, e.g., Sonneratia alba and Avicennia marina (instead of the popular Rhizophora apiculata, R. mucronata and R. stylosa).

  15. Lower Brule Lagoon System NPDES Permit

    EPA Pesticide Factsheets

    Under NPDES permit number SD-0020800, Lower Brule Rural Water is authorized to discharge from its wastewater lagoon system serving the town of Lower Brule, located in Lyman County, South Dakota, to the bank of the Missouri River (Lake Sharpe).

  16. Evolutionary resilience and complex lagoon systems.

    PubMed

    Davoudi, Simin; Zaucha, Jacek; Brooks, Elizabeth

    2016-10-01

    The present study applies an evolutionary resilience framework to complex socioecological systems in the coastal regions in Europe with a particular focus on lagoons. Despite their variations, lagoons share common challenges in achieving effective and sustainable ways of governing and managing economic, social, and environmental uncertainties. Our aim is to demonstrate that building resilience involves planning not only for recovery from shocks but also for cultivating preparedness and seeking potential transformative opportunities that emerge from change. The framework consists of 4 dimensions: persistence, adaptability, transformability, and preparedness. To illustrate how this 4-dimensional framework can be applied to the specific context of lagoons, we draw on examples of good and poor practices from the 10 lagoons studied as part of the ARCH project. Integr Environ Assess Manag 2016;12:711-718. © 2016 SETAC. © 2016 SETAC.

  17. Into the Depths of the Lagoon Nebula

    NASA Image and Video Library

    2011-09-16

    Swirling dust clouds and bright newborn stars dominate the view in this image of the Lagoon nebula from NASA Spitzer Space Telescope. The nebula lies in the general direction of the center of our galaxy in the constellation Sagittarius.

  18. Hydrodynamic Modeling of Diego Garcia Lagoon

    DTIC Science & Technology

    2014-08-01

    largest coral reef atoll of more than 60 islands that make up the Chagos Archipelago south of the equator in the central Indian Ocean. It is located at...quality and coral reef health. Hydrodynamic modeling of lagoon waters is one key component of the investigation to understand lagoon circulation...NAVFAC and other researchers will then use the flushing time information to assess water quality conditions and coral reef health. Researchers use

  19. [Nutrients in 39 Mexican coastal lagoons].

    PubMed

    Contreras, F; Castañeda, O; Torres-Alvarado, R; Gutiérrez, F

    1996-08-01

    An analysis of 39 Mexican coastal lagoons most in tropical environments, shows no nutrient limitation for primary productivity: even minimum nutrient values are higher than those of similar systems (mostly of temperate zones). In some cases, nutrient variations are large and indicative of heterogeneity. The N:P ratio is more important than simple nutrient concentrations. Using this ratio, coastal lagoons are classified as limited in nitrogen (< 5) or phosphorus (> 10).

  20. Bioinformatics study of the mangrove actin genes

    NASA Astrophysics Data System (ADS)

    Basyuni, M.; Wasilah, M.; Sumardi

    2017-01-01

    This study describes the bioinformatics methods to analyze eight actin genes from mangrove plants on DDBJ/EMBL/GenBank as well as predicted the structure, composition, subcellular localization, similarity, and phylogenetic. The physical and chemical properties of eight mangroves showed variation among the genes. The percentage of the secondary structure of eight mangrove actin genes followed the order of a helix > random coil > extended chain structure for BgActl, KcActl, RsActl, and A. corniculatum Act. In contrast to this observation, the remaining actin genes were random coil > extended chain structure > a helix. This study, therefore, shown the prediction of secondary structure was performed for necessary structural information. The values of chloroplast or signal peptide or mitochondrial target were too small, indicated that no chloroplast or mitochondrial transit peptide or signal peptide of secretion pathway in mangrove actin genes. These results suggested the importance of understanding the diversity and functional of properties of the different amino acids in mangrove actin genes. To clarify the relationship among the mangrove actin gene, a phylogenetic tree was constructed. Three groups of mangrove actin genes were formed, the first group contains B. gymnorrhiza BgAct and R. stylosa RsActl. The second cluster which consists of 5 actin genes the largest group, and the last branch consist of one gene, B. sexagula Act. The present study, therefore, supported the previous results that plant actin genes form distinct clusters in the tree.

  1. A multi-proxy approach to tsunami deposit characterization: searching wetlands and lagoons at the Mexican Pacific coast for a record of tsunami inundations

    NASA Astrophysics Data System (ADS)

    Ramirez-Herrera, M.; Cundy, A.; Kostoglodov, V.; Carranza-Edwards, A.; Morales, E.; Metcalfe, S.

    2007-05-01

    It is extremely important to integrate historic accounts with geologic evidence of past tsunamis to fully understand hazards to the highly populated Mexican coast. We aim to complete a record of tsunami events using a multi- proxy approach to identify tsunami deposits recovered from marsh lagoonal sediments on the Guerrero coast of Mexico. Core samples from nine study sites on tropical wetlands show distinct stratigraphic changes with depth, indicating clear rapid change in depositional environments over time. Core sequences recovered include evidence of land level changes and three probable tsunamis based on stratigraphic, granulometric, geochemical, and microfossil analysis (diatoms and pollen) of marsh sediments. Radiocarbon data indicate that the sediment units cored are up to ca. 6161+/- 53 yr BP. A probable tsunami event and coseismic subsidence dates back at 3800 yr BP. Discrete sand units fining up show sharp erosional contacts at the base, medium to poor sorting, fine to coarse sand, with clay/mud rip-up clasts. However, traces of these apparent tsunami deposits are not extensive over a large area and we could not correlate them from one site to another. We hypothesize that the distribution and preservation of tsunami deposits in these tropical lagoonal marshes and wetlands might be controlled by mangrove vegetation fringing coastal lagoons and estuaries. Recent observations after the 2004 Indian Ocean tsunami showed that mangroves may dissipate tsunami energy and result in flumed-shape sediment deposition. If this is the case, finding tsunami deposits over extensive areas in mangrove marshes and wetlands would prove very challenging.

  2. Discharge diversion in the Patía River delta, the Colombian Pacific: Geomorphic and ecological consequences for mangrove ecosystems

    NASA Astrophysics Data System (ADS)

    Restrepo, Juan D.; Cantera, Jaime R.

    2013-10-01

    ía catchment have been more pronounced during the decades of 1970-1980 and 1990-2000, as a result of land degradation and deforestation. The high sediment and freshwater inputs into the mangrove ecosystem create additional stress (both at ongoing background levels and, occasionally, at dramatic levels), which may periodically push local environmental parameters beyond the thresholds for mangrove survival. The future environmental state of the Sanquianga Mangrove National Reserve deserves more scientific and governmental attention.

  3. Mangrove macrobenthos: Assemblages, services, and linkages

    NASA Astrophysics Data System (ADS)

    Lee, S. Y.

    2008-02-01

    Macrobenthic assemblages are relatively poorly known compared to other components of the mangrove ecosystem. Tropical mangroves support macrobenthic biodiversity resources yet to be properly documented and interpreted. Some methodological challenges, such as the generally high spatial heterogeneity and complexity of the habitat, evidently reduce sampling efficiency and accuracy, while also leaving some microhabitats under-sampled. Macrobenthic assemblage structure seems to be influenced by local environmental conditions, such as hydroperiod, organic matter availability and sediment characteristics. Brachyurans, gastropods and oligochaetes dominate in the sediment, with the former two groups also common on hard surfaces provided by tree trunks, while insects and arachnids inhabit the canopy. Traditionally, studies of mangrove macrobenthos have focused on assemblage structure or the biology of individual species, but more complex inter-specific interactions and the inter-relationship between habitat and the biota are recently being addressed. Brachyuran crabs are the best-studied macrobenthos group, but many issues about their role in mangrove ecosystem dynamics are still controversial. Despite many species of mangrove macrobenthos being referred to as 'trophic dead ends', most serve as important links between recalcitrant mangrove organic matter and estuarine secondary production, through feeding excursion by mobile nekton during the high tide, and macrobenthos-mediated processing and exportation of organic matter. A significant difference in the standing crop biomass of forests between the Indo-west-Pacific (IWP)' and Atlantic-east-Pacific (AEP) mangroves may be related to the difference in species richness of mangrove as well as macrobenthos diversity in the two bioregions. Such differences in assemblage structure may also result in different ecosystem functioning, but the nature of the links is, however, yet to be explored. There is also a strong need for

  4. Spatial and temporal land cover changes in Terminos Lagoon Reserve, Mexico.

    PubMed

    Soto-Galera, Ernesto; Piera, Jaume; López, Pilar

    2010-06-01

    Terminos Lagoon ecosystem is the largest fluvial-lagoon estuarine system in the country and one of the most important reserves of coastal flora and fauna in Mexico. Since the seventies, part of the main infrastructure for country's oil extraction is located in this area. Its high biodiversity has motivated different type of studies including deforestation processes and land use planning. In this work we used satellite image analysis to determine land cover changes in the area from 1974 to 2001. Our results indicate that tropical forest and mangroves presented the most extensive losses in its coverage. In contrast, urban areas and induced grassland increased considerably. In 2001 more than half of the ecosystem area showed changes from its original land cover, and a third part of it was deteriorated. The main causes of deforestation were both the increase in grassland and the growth of urban areas. However, deforestation was attenuated by natural reforestation and plant canopy recovery. We conclude that the introduction of cattle and urban development were the main causes for the land cover changes; however, the oil industry activity located in the ecosystem, has promoted indirectly to urban growth and rancher boom.

  5. Mangrove species mapping in Kuala Sepetang Mangrove Forest, Perak using high resolution airborne data

    NASA Astrophysics Data System (ADS)

    Beh, B. C.; MatJafri, M. Z.; Lim, H. S.

    2015-10-01

    Mangrove vegetation is widely employed and studied as it is a unique ecosystem which is able to provide plenty of goods and applications to our country. In this paper, high resolution airborne image data obtained the flight mission on Kuala Sepetang Mangrove Forest Reserve, Perak, Malaysia will be used for mangrove species mapping. Supervised classification using the retrieved surface reflectance will be performed to classify the airborne data using Geomatica 2013 software package. The ground truth data will be used to validate the classification accuracy. High correlation of R2=0.873 was achieved in this study indicate that high resolution airborne data is reliable and suitable used for mangrove species mapping.

  6. Does coastal lagoon habitat quality affect fish growth rate and their recruitment? Insights from fishing and acoustic surveys

    NASA Astrophysics Data System (ADS)

    Brehmer, P.; Laugier, T.; Kantoussan, J.; Galgani, F.; Mouillot, D.

    2013-07-01

    Ensuring the sustainability of fish resources necessitates understanding their interaction with coastal habitats, which is becoming ever more challenging in the context of ever increasing anthropogenic pressures. The ability of coastal lagoons, exposed to major sources of disturbance, to provide resources and suitable habitats for growth and survival of juvenile fish is especially important. We analysed three lagoons with different ecological statuses and habitat quality on the basis of their eutrophication and ecotoxicity (Trix test) levels. Fish abundances were sampled using fishing and horizontal beaming acoustic surveys with the same protocols in the same year. The relative abundance of Anguilla anguilla, Dicentrarchus labrax or the Mugilidae group was not an indicator of habitat quality, whereas Atherina boyeri and Sparus aurata appeared to be more sensitive to habitat quality. Fish abundance was higher in the two lagoons with high eutrophication and ecotoxicity levels than in the less impacted lagoon, while fish sizes were significantly higher in the two most severely impacted lagoons. This leads us to suggest low habitat quality may increase fish growth rate (by the mean of a cascading effect), but may reduce lagoon juvenile abundance by increasing larval mortality. Such a hypothesis needs to be further validated using greater investigations which take into account more influences on fish growth and recruitment in such variable environments under complex multi-stressor conditions.

  7. Meiofauna in closed coastal saline lagoons in the United Kingdom: Structure and biodiversity of the nematode assemblage

    NASA Astrophysics Data System (ADS)

    Barnes, N.; Bamber, R. N.; Moncrieff, C. B.; Sheader, M.; Ferrero, T. J.

    2008-08-01

    Coastal saline lagoons are rare in North West Europe and tend to be closed, brackish water systems. In the United Kingdom they are small and isolated, each exhibiting extremely variable habitat conditions, both spatially and temporally. This paper represents the first species-level study of lagoonal nematode assemblages in the UK. Samples were taken from seven ponds in a saline lagoon system on the south coast of England in order to describe the nematode assemblage in relation to habitat type and to assess the possibility of lagoonal specialisation. At each site samples were also taken, or data were already available, for salinity, sediment granulometry, sediment organic carbon content, photosynthetic pigments and lagoon topography. A lagoonal specialist nematode fauna was not identified, but it was found that the nematode communities strongly reflected the differences between environmental conditions in the lagoons. Sample and site diversity were found to be relatively similar, but the importance of habitat networks was indicated by the relatively high system diversity, species turnover being highest between lagoons with different salinity and/or granulometry regimes. Salinity was the principal factor correlated with assemblage structure and species diversity was highest at the higher salinity sites. Median salinity (averaged from weekly records over the previous 4 months) correlated more clearly with nematode assemblage structure than salinity at the time of sampling. This shows the importance of considering historical as well as contemporaneous data when undertaking ecological studies: Contemporary conditions may influence species fecundity, and therefore relative abundances, whilst historic conditions may influence species occurrence through the effects of recruitment and survival.

  8. Pyrite as a proxy for the identification of former coastal lagoons in semiarid NE Brazil

    NASA Astrophysics Data System (ADS)

    Ferreira, Tiago O.; Nóbrega, Gabriel N.; Albuquerque, Antonia G. B. M.; Sartor, Lucas R.; Gomes, Irlene S.; Artur, Adriana G.; Otero, Xosé L.

    2015-10-01

    This work aimed to test the suitability of pyrite (FeS2) as a proxy for reconstructing past marine environmental conditions along the semiarid coast of Brazil. Morphological description combined with physicochemical analyses including Fe partitioning were conducted for soil depth profiles (30 and 60 cm depths) at three sites in two contrasting lagoons of the state of Ceará: a suspected former lagoon that would have been transformed into a freshwater "lake" at a site vegetated by Juncus effusus (site P1), and another lagoon with connection to the sea at sites vegetated by J. effusus (site P2) or Portulaca oleracea (site P3). Soil samples were collected in September 2010. Site P3 had more reducing conditions, reaching Eh values of -132 mV in the surface layer (0-10 cm), whereas minimum values for the P1 and P2 sites were +219 and +85 mV, respectively. Lower pyritic Fe values were found at site P1, with a degree of pyritization (DOP) ranging from 10 to 13%. At sites P2 and P3, DOP ranged from 9 to 67% and from 55 to 72%, respectively. These results are consistent with an interruption of tidal channels by eolian dune migration inducing strong changes in the hydrodynamics and physicochemical characteristics (lower salinity, oxidizing conditions) of these sites, causing the dieback of suspected former mangroves and a succession to freshwater marshes with an intermediate salt marsh stage. Together with other physicochemical signatures, pyrite can evidently serve as a useful proxy in tracking environmental changes in such ecotones, with implications for coastal management.

  9. Mangrove vulnerability modelling in parts of Western Niger Delta, Nigeria using satellite images, GIS techniques and Spatial Multi-Criteria Analysis (SMCA).

    PubMed

    Omo-Irabor, Omo O; Olobaniyi, Samuel B; Akunna, Joe; Venus, Valentijn; Maina, Joseph M; Paradzayi, Charles

    2011-07-01

    Mangroves are known for their global environmental and socioeconomic value. Despite their importance, mangrove like other ecosystems is now being threatened by natural and human-induced processes that damage them at alarming rates, thereby diminishing the limited number of existing mangrove vegetation. The development of a spatial vulnerability assessment model that takes into consideration environmental and socioeconomic criteria, in spatial and non-spatial formats has been attempted in this study. According to the model, 11 different input parameters are required in modelling mangrove vulnerability. These parameters and their effects on mangrove vulnerability were selected and weighted by experts in the related fields. Criteria identification and selection were mainly based on effects of environmental and socioeconomic changes associated with mangrove survival. The results obtained revealed the dominance of socioeconomic criteria such as population pressure and deforestation, with high vulnerability index of 0.75. The environmental criteria was broadly dispersed in the study area and represents vulnerability indices ranging from 0.00-0.75. This category reflects the greater influence of pollutant input from oil wells and pipelines and minimal contribution from climatic factors. This project has integrated spatial management framework for mangrove vulnerability assessment that utilises information technology in conjunction with expert knowledge and multi-criteria analysis to aid planners and policy/ decision makers in the protection of this very fragile ecosystem.

  10. KENNEDY SPACE CENTER, FLA. - Karen Holloway-Adkins, KSC wildlife specialist, searches the Banana River for a grass specimen. In the background is one of the launch pads. The biologist is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

    NASA Image and Video Library

    2004-02-05

    KENNEDY SPACE CENTER, FLA. - Karen Holloway-Adkins, KSC wildlife specialist, searches the Banana River for a grass specimen. In the background is one of the launch pads. The biologist is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

  11. KENNEDY SPACE CENTER, FLA. - From a boat on the Banana River the Vehicle Assembly Building looms over the water. The boat holds Karen Holloway-Adkins, KSC wildlife specialist, who is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

    NASA Image and Video Library

    2004-02-05

    KENNEDY SPACE CENTER, FLA. - From a boat on the Banana River the Vehicle Assembly Building looms over the water. The boat holds Karen Holloway-Adkins, KSC wildlife specialist, who is studying the life history of sea turtles, especially what they eat, where they lay their eggs and what factors might harm their survival. On the boat trip she is also monitoring the growth of sea grasses and algae and the water quality of estuaries and lagoons used by sea turtles and other aquatic wildlife.

  12. Interspecific variations in mangrove leaf litter decomposition are related to labile nitrogenous compounds

    NASA Astrophysics Data System (ADS)

    Nordhaus, Inga; Salewski, Tabea; Jennerjahn, Tim C.

    2017-06-01

    Mangrove leaves form a large pool of carbon, nitrogen and energy that is a major driver of element cycles and detrital food webs inside mangrove forests as well as in adjacent coastal waters. However, there are large gaps in knowledge on the transformation pathways and ultimate fate of leaf nitrogen. Therefore, the main objective of this study was to determine the amount and composition of nitrogenous organic matter and possible species-specific differences during the decomposition of mangrove leaf litter. For that purpose a three month decomposition experiment with litterbags was conducted using leaves of Aegiceras corniculatum, Avicennia alba, Ceriops decandra, Rhizophora apiculata, and Sonneratia caseolaris in the mangrove forest of the Segara Anakan Lagoon, Java, Indonesia. Detrital leaves were analyzed for bulk carbon and total nitrogen (N), stable carbon and nitrogen isotope composition (δ13C, δ15N), total hydrolyzable amino acids (THAA) and total hydrolyzable hexosamines (THHA). Decomposition rates (k d-1) were highest and tM50 values (when 50% of the original mass had been degraded) lowest in S. caseolaris (k = 0.0382 d-1; tM50 = 18 days), followed by A. alba, C. decandra, A. corniculatum, and R. apiculata (k = 0.0098 d-1; tM50 = 71 days). The biochemical composition of detrital leaves differed significantly among species and over time. S. caseolaris and A. alba had higher concentrations of N, THAA and THHA and a lower C/N ratio than the other three species. For most of the species concentrations of N, THAA and THHA increased during decomposition. The hexosamine galactosamine, indicative of bacterial cell walls, was first found in leaves after 5-7 days of decomposition and increased afterwards. Our findings suggest an increasing, but species-specific varying, portion of labile nitrogenous OM and total N in decomposing leaves over time that is partly related to the activity of leaf-colonizing bacteria. Despite a higher relative nitrogen content in the

  13. Flushing of a coastal lagoon in the Red Sea

    NASA Astrophysics Data System (ADS)

    Sultan, S. A. R.; Ahmad, F.

    1990-09-01

    Shu'aiba Lagoon (Lat. 20°45'N; Long. 39°28'E) is located on the eastern coast of the Red Sea. It is relatively shallow with an area of approximately 11·7 km 2. The inlet to the lagoon is narrow with a cross-sectional area of about 245 m 2. This lagoon is a future site to develop mariculture. With this objective in view the flushing time scale of the lagoon was calculated, as flushing is an important abiotic factor in lagoon ecology. The average flushing time for the months February to June and September to November is about 20 days. Oceanic inputs play an important part in the process of fertilization of the lagoons. The marine environment in arid zone lagoons is under natural stress due to high temperatures and salinities. However, the flushing time scale of 20 days may not exert intolerable stress on the ecology of the Shu'aiba Lagoon.

  14. The fate of Mediterranean lagoons under climate change

    NASA Astrophysics Data System (ADS)

    Umgiesser, Georg; Ferrarin, Christian; Cucco, Andrea; De Pascalis, Francesca; Ghezzo, Michol; Bellafiore, Debora; Bajo, Marco

    2014-05-01

    A numerical model (SHYFEM) has been applied to 10 Mediterranean lagoons and a comparison study between the lagoons has been carried out. The lagoons are the lagoons of Venice, Marano-Grado, Varano and Lesina in the Adriatic Sea, the Taranto basin in the Ionian Sea, the Cabras lagoon in Sardinia, and the lagoons of Ganzirri and Faro in Sicily, the Mar Menor in Spain and the Nador lagoon in Morocco. These lagoons give a representative picture of the lagoons situated around the Mediterranean basin. The lagoons range from a leaky type of lagoons to a choked type. The number of inlets ranges from just one in the Nador lagoon to 6 in the case of the Marano-Grado lagoons. Tidal range is from nano-tidal to micro-tidal. The depth ranges from an average depth of 1 m to up to 40 meters. The model is a finite element model, especially suited to shallow water basins with complicated geometric and morphologic variations. The model can compute the basic hydrodynamics, dispersion of tracers, temperature and salinity evolution, sediment transport and ecological parameters. Building on an earlier study that focused on the classification of Mediterranean lagoons based on hydrodynamics, exchange rates and renewal time, this study is concerned with the changes in physical parameters under climate change. Data from IPCC has been used to simulate the changes in renewal time, salinity and temperature of all lagoons, with respect to the control simulation. Whenever possible downscaled data for the Mediterranean basin have been used. Sea level rise scenarios are taken from the last IPCC report. The model has been applied in its 3D version and the chosen setup allows a comparison between results in the different lagoons. Results indicate that the differences of renewal time between all studied lagoons become smaller. This means that leaky lagoons become less leaky and choked lagoons less choked. What concerns temperature and salinity, changes occurring in the sea are amplified inside lagoons

  15. Mangrove dieback during fluctuating sea levels.

    PubMed

    Lovelock, Catherine E; Feller, Ilka C; Reef, Ruth; Hickey, Sharyn; Ball, Marilyn C

    2017-05-10

    Recent evidence indicates that climate change and intensification of the El Niño Southern Oscillation (ENSO) has increased variation in sea level. Although widespread impacts on intertidal ecosystems are anticipated to arise from the sea level seesaw associated with climate change, none have yet been demonstrated. Intertidal ecosystems, including mangrove forests are among those ecosystems that are highly vulnerable to sea level rise, but they may also be vulnerable to sea level variability and extreme low sea level events. During 16 years of monitoring of a mangrove forest in Mangrove Bay in north Western Australia, we documented two forest dieback events, the most recent one being coincident with the large-scale dieback of mangroves in the Gulf of Carpentaria in northern Australia. Diebacks in Mangrove Bay were coincident with periods of very low sea level, which were associated with increased soil salinization of 20-30% above pre-event levels, leading to canopy loss, reduced Normalized Difference Vegetation Index (NDVI) and reduced recruitment. Our study indicates that an intensification of ENSO will have negative effects on some mangrove forests in parts of the Indo-Pacific that will exacerbate other pressures.

  16. Trophic behaviour of juvenile reef fishes inhabiting interlinked mangrove-seagrass habitats in offshore mangrove islets

    EPA Science Inventory

    Mangroves are essential fish habitats acting as shelters and nurseries, but the relative contribution of mangrove resources to fish diets relies on site-specific context and fish life history stage. Stable isotope (δ13C, δ15N) and gut-content analyses were used to investigate siz...

  17. Saltmarsh boundary modulates dispersal of mangrove propagules: implications for mangrove migration with sea-level rise.

    PubMed

    Peterson, Jennifer M; Bell, Susan S

    2015-01-01

    Few studies have empirically examined the suite of mechanisms that underlie the distributional shifts displayed by organisms in response to changing climatic condition. Mangrove forests are expected to move inland as sea-level rises, encroaching on saltmarsh plants inhabiting higher elevations. Mangrove propagules are transported by tidal waters and propagule dispersal is likely modified upon encountering the mangrove-saltmarsh ecotone, the implications of which are poorly known. Here, using an experimental approach, we record landward and seaward dispersal and subsequent establishment of mangrove propagules that encounter biotic boundaries composed of two types of saltmarsh taxa: succulents and grasses. Our findings revealed that propagules emplaced within saltmarsh vegetation immediately landward of the extant mangrove fringe boundary frequently dispersed in the seaward direction. However, propagules moved seaward less frequently and over shorter distances upon encountering boundaries composed of saltmarsh grasses versus succulents. We uniquely confirmed that the small subset of propagules dispersing landward displayed proportionately higher establishment success than those transported seaward. Although impacts of ecotones on plant dispersal have rarely been investigated in situ, our experimental results indicate that the interplay between tidal transport and physical attributes of saltmarsh vegetation influence boundary permeability to propagules, thereby directing the initial phase of shifting mangrove distributions. The incorporation of tidal inundation information and detailed data on landscape features, such as the structure of saltmarsh vegetation at mangrove boundaries, should improve the accuracy of models that are being developed to forecast mangrove distributional shifts in response to sea-level rise.

  18. Trophic behaviour of juvenile reef fishes inhabiting interlinked mangrove-seagrass habitats in offshore mangrove islets

    EPA Science Inventory

    Mangroves are essential fish habitats acting as shelters and nurseries, but the relative contribution of mangrove resources to fish diets relies on site-specific context and fish life history stage. Stable isotope (δ13C, δ15N) and gut-content analyses were used to investigate siz...

  19. Saltmarsh Boundary Modulates Dispersal of Mangrove Propagules: Implications for Mangrove Migration with Sea-Level Rise

    PubMed Central

    Peterson, Jennifer M.; Bell, Susan S.

    2015-01-01

    Few studies have empirically examined the suite of mechanisms that underlie the distributional shifts displayed by organisms in response to changing climatic condition. Mangrove forests are expected to move inland as sea-level rises, encroaching on saltmarsh plants inhabiting higher elevations. Mangrove propagules are transported by tidal waters and propagule dispersal is likely modified upon encountering the mangrove-saltmarsh ecotone, the implications of which are poorly known. Here, using an experimental approach, we record landward and seaward dispersal and subsequent establishment of mangrove propagules that encounter biotic boundaries composed of two types of saltmarsh taxa: succulents and grasses. Our findings revealed that propagules emplaced within saltmarsh vegetation immediately landward of the extant mangrove fringe boundary frequently dispersed in the seaward direction. However, propagules moved seaward less frequently and over shorter distances upon encountering boundaries composed of saltmarsh grasses versus succulents. We uniquely confirmed that the small subset of propagules dispersing landward displayed proportionately higher establishment success than those transported seaward. Although impacts of ecotones on plant dispersal have rarely been investigated in situ, our experimental results indicate that the interplay between tidal transport and physical attributes of saltmarsh vegetation influence boundary permeability to propagules, thereby directing the initial phase of shifting mangrove distributions. The incorporation of tidal inundation information and detailed data on landscape features, such as the structure of saltmarsh vegetation at mangrove boundaries, should improve the accuracy of models that are being developed to forecast mangrove distributional shifts in response to sea-level rise. PMID:25760867

  20. [Factors involved in coastal lagoons formation in Colombian southwest Caribbean].

    PubMed

    Alvarez-León, Ricardo; Mendoza-Mazzeo, Luis Alberto; Vernette, Georges

    2003-01-01

    Based on origin, geomorphological evolution and environmental characteristics, four of the main types of coastal lagoons were identified in colombian southwest Caribbean. The following are examples of each type: (1) Terrigenous sediment inputs in delta environment (Lagoons from Sinu River Delta, Cordoba Department), (2) Shore sand bars in coastal flat (Tesca Lagoon, Bolivar Deparment), (3) bar built by organisms such as coral reefs, (Isla Grande Lagoons, Bolivar Deparment) and, (4) bars controlled by tectonism (Cartagena Bay, Bolivar Deparment).

  1. Report to Congress: Municipal Wastewater Lagoon Study. Volume 1

    SciTech Connect

    Not Available

    1987-11-01

    This report presents the results of the Municipal Wastewater Lagoon Study performed by the USEPA in response to Section 3018 of RCRA and Sec. 246 of the Hazardous and Solid Waste amendments of 1984. The objectives are to determine: number and size of municipal lagoons; types and quantities of waste contained in such lagoons; the extent to which such waste has been or may be released from such lagoons and contaminates ground water; and available alternatives for preventing or controlling such releases.

  2. Early-diagenetic processes in marine mangrove sediments from Guadeloupe, French West Indies

    NASA Astrophysics Data System (ADS)

    Crémière, Antoine; Sebilo, Mathieu; Strauss, Harald; Gros, Olivier; Laverman, Anniet M.

    2014-05-01

    Sediment and pore-water geochemistry were investigated in two short sediment cores from the Manche-à-eau lagoon (Guadeloupe, French Caribbean island) surrounded by mangroves trees. These sediments present high total organic carbon content, ranging between 10 to 18 % wt, mainly originating from mangrove litter fall. Oxygen is depleted in the first few millimetres of the sediment indicating active organic carbon degradation. Seawater sulphate is entirely consumed within the first 20 cm of the sediments and total organic carbon content decreases with depth pointing out that early-diagenetic degradation of organic matter occurs with sulphate reduction. Sulphide produced as the results of sulphate reduction partly reacts with detrital iron-bearing minerals and precipitates as pyrite which is consistent with high amounts of sulphur in the sediments (4-5 % wt). The sulphur isotopic composition (δ34S) of both dissolved sulphate and sulphide in pore-water increases with depth displaying a large apparent isotopic fractionation (Δ34S) between both species of 65-80o as a result of bacterial sulphate reduction. Scanning electron microscopy investigation reveals that a part of the carbonate alkalinity produced either by organic matter oxidation or anaerobic methane oxidation leads to authigenic carbonates precipitation. These results provide straightforward evidence that carbon and sulphur biogeochemical cycles are intimately governed by sedimentary microbial activity.

  3. Comparative Analysis of Transcriptomes in Rhizophoraceae Provides Insights into the Origin and Adaptive Evolution of Mangrove Plants in Intertidal Environments

    PubMed Central

    Guo, Wuxia; Wu, Haidan; Zhang, Zhang; Yang, Chao; Hu, Ling; Shi, Xianggang; Jian, Shuguang; Shi, Suhua; Huang, Yelin

    2017-01-01

    Mangroves are woody plants that grow at the interface between land and sea in tropical and subtropical latitudes, where they exist in conditions of high salinity, extreme tides, strong winds, high temperatures, and muddy, anaerobic soils. Rhizophoraceae is a key mangrove family, with highly developed morphological and physiological adaptations to extreme conditions. It is an ideal system for the study of the origin and adaptive evolution of mangrove plants. In this study, we characterized and comprehensively compared the transcriptomes of four mangrove species, from all four mangrove genera, as well as their closest terrestrial relative in Rhizophoraceae, using RNA-Seq. We obtained 41,936–48,845 unigenes with N50 values of 982–1,185 bp and 61.42–69.48% annotated for the five species in Rhizophoraceae. Orthology annotations of Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Clusters of Orthologous Groups revealed overall similarities in the transcriptome profiles among the five species, whereas enrichment analysis identified remarkable genomic characteristics that are conserved across the four mangrove species but differ from their terrestrial relative. Based on 1,816 identified orthologs, phylogeny analysis and divergence time estimation revealed a single origin for mangrove species in Rhizophoraceae, which diverged from the terrestrial lineage ~56.4 million years ago (Mya), suggesting that the transgression during the Paleocene–Eocene Thermal Maximum may have been responsible for the entry of the mangrove lineage of Rhizophoraceae into intertidal environments. Evidence showed that the ancestor of Rhizophoraceae may have experienced a whole genome duplication event ~74.6 Mya, which may have increased the adaptability and survival chances of Rhizophoraceae during and following the Cretaceous–Tertiary extinction. The analysis of positive selection identified 10 positively selected genes from the ancestor branch of Rhizophoraceae mangroves, which

  4. Global patterns in mangrove soil carbon stocks and losses

    NASA Astrophysics Data System (ADS)

    Atwood, Trisha B.; Connolly, Rod M.; Almahasheer, Hanan; Carnell, Paul E.; Duarte, Carlos M.; Ewers Lewis, Carolyn J.; Irigoien, Xabier; Kelleway, Jeffrey J.; Lavery, Paul S.; Macreadie, Peter I.; Serrano, Oscar; Sanders, Christian J.; Santos, Isaac; Steven, Andrew D. L.; Lovelock, Catherine E.

    2017-07-01

    Mangrove soils represent a large sink for otherwise rapidly recycled carbon (C). However, widespread deforestation threatens the preservation of this important C stock. It is therefore imperative that global patterns in mangrove soil C stocks and their susceptibility to remineralization are understood. Here, we present patterns in mangrove soil C stocks across hemispheres, latitudes, countries and mangrove community compositions, and estimate potential annual CO2 emissions for countries where mangroves occur. Global potential CO2 emissions from soils as a result of mangrove loss were estimated to be ~7.0 Tg CO2e yr-1. Countries with the highest potential CO2 emissions from soils are Indonesia (3,410 Gg CO2e yr-1) and Malaysia (1,288 Gg CO2e yr-1). The patterns described serve as a baseline by which countries can assess their mangrove soil C stocks and potential emissions from mangrove deforestation.

  5. Nutrient-Chlorophyll Relationships in the Indian River Lagoon, Florida

    EPA Science Inventory

    The Indian River Lagoon is a highly diverse estuary located along Florida’s Atlantic coast. The system is made up of the main stem and two side-lagoons: the Banana River and Mosquito Lagoon. We segmented the main stem into three sections based on spatial trends in water quality ...

  6. Nitrifier activity and diversity in swine lagoon covers

    USDA-ARS?s Scientific Manuscript database

    Ammonia emissions from swine waste lagoons pose an environmental challenge to current pork production practices. Semi-permeable lagoon covers limit ammonia emissions by minimizing the effect of wind on the lagoon surface. Additionally, semi-permeable covers may also act as an attachment site for b...

  7. Accuracy of lagoon gas emissions using an inverse dispersion method

    USDA-ARS?s Scientific Manuscript database

    Measuring gas emissions from treatment lagoons and storage ponds poses challenging conditions for existing micrometeorological techniques because of non-ideal wind conditions. These include those induced by trees and crops surrounding the lagoons, and lagoons with dimensions too small to establish ...

  8. Inverse-dispersion technique for assessing lagoon gas emissions

    USDA-ARS?s Scientific Manuscript database

    Measuring gas emissions from treatment lagoons and storage ponds poses challenging conditions for existing micrometeorological techniques because of non-ideal wind conditions, such as those induced by trees and crops surrounding the lagoons, and lagoons with dimensions too small to establish equilib...

  9. Nutrient-Chlorophyll Relationships in the Indian River Lagoon, Florida

    EPA Science Inventory

    The Indian River Lagoon is a highly diverse estuary located along Florida’s Atlantic coast. The system is made up of the main stem and two side-lagoons: the Banana River and Mosquito Lagoon. We segmented the main stem into three sections based on spatial trends in water quality ...

  10. Facultative Lagoons. Student Manual. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Andersen, Lorri

    The textual material for a unit on facultative lagoons is presented in this student manual. Topic areas discussed include: (1) loading; (2) microbial theory; (3) structure and design; (4) process control; (5) lagoon start-up; (6) data handling and analysis; (7) lagoon maintenance (considering visual observations, pond structure, safety, odor,…

  11. Mapping disturbances in a mangrove forest using multi-date landsat TM imagery.

    PubMed

    Kovacs, J M; Wang, J; Blanco-Correa, M

    2001-05-01

    To evaluate the accounts of local fishermen, Landsat TM images (1986, 1993, 1999) were examined to assess potential losses in the mangrove forests of the Teacapán-Agua Brava lagoon system, Mexico. A binary change mask derived from image differencing of a band 4/3 ratio was employed to calculate any changes within this forested wetland. The results indicate that by 1986 approximately 18% (or 86 km2) of the mangrove area under study was either dead or in poor condition. The majority of this damage had occurred in the eastern section of the Agua Brava basin, which coincides, with the reports of the elderly fishermen. Examination of aerial photographs from 1970 revealed no adverse impacts in this area and would suggest, as postulated by the fishermen and other scientists, that modifications in environmental conditions following the opening of a canal, Cuautlá canal, in 1972 may have initiated the large-scale mortality. Although these areas of impact are still developing, the results from the satellite data indicate that the majority of the more recent changes are occurring elsewhere in the system. Obvious in the 1999 satellite data, but not so in the 1993, are large areas of mangrove degradation in the northern section of the Teacapán region. In the Agua Brava basin, the more recent transformations are appearing on the western side of the basin. Since long-term records of environmental conditions are absent, it is difficult to determine why these latest changes are occurring or even if the earlier losses were the result of the canal. Potential agents of change that have recently been observed include a hurricane, a second canal, and the uncontrolled expansion of the Cuautlá canal since 1994.

  12. Nutrient addition differentially affects ecological processes of Avicennia germinans in nitrogen versus phosphorus limited mangrove ecosystems

    USGS Publications Warehouse

    Feller, Ilka C.; Lovelock, C.E.; McKee, K.L.

    2007-01-01

    Nutrient over-enrichment is a major threat to marine environments, but system-specific attributes of coastal ecosystems may result in differences in their sensitivity and susceptibility to eutrophication. We used fertilization experiments in nitrogen (N)- and phosphorus (P)-limited mangrove forests to test the hypothesis that alleviating different kinds of nutrient limitation may have different effects on ecosystem structure and function in natural systems. We compared a broad range of ecological processes to determine if these systems have different thresholds where shifts might occur in nutrient limitation. Growth responses indicated N limitation in Avicennia germinans (black mangrove) forests in the Indian River Lagoon (IRL), Florida, and P limitation at Twin Cays, Belize. When nutrient deficiency was relieved, A. germinans grew out of its stunted form by increasing wood relative to leaf biomass and shoot length relative to lateral growth. At the P-limited site, P enrichment (+P) increased specific leaf area, N resorption, and P uptake, but had no effect on P resorption. At the N-limited site, +N increased both N and P resorption, but did not alter biomass allocation. Herbivory was greater at the P-limited site and was unaffected by +P, whereas +N led to increased herbivory at the N-limited site. The responses to nutrient enrichment depended on the ecological process and limiting nutrient and suggested that N- versus P-limited mangroves do have different thresholds. +P had a greater effect on more ecological processes at Twin Cays than did +N at the IRL, which indicated that the P-limited site was more sensitive to nutrient loading. Because of this sensitivity, eutrophication is more likely to cause a shift in nutrient limitation at P-limited Twin Cays than N-limited IRL. ?? 2007 Springer Science+Business Media, LLC.

  13. How to save the rarest Darwin's finch from extinction: the mangrove finch on Isabela Island

    PubMed Central

    Fessl, Birgit; Young, Glyn H.; Young, Richard P.; Rodríguez-Matamoros, Jorge; Dvorak, Michael; Tebbich, Sabine; Fa, John E.

    2010-01-01

    Habitat destruction and predation by invasive alien species has led to the disappearance of several island populations of Darwin's finches but to date none of the 13 recognized species have gone extinct. However, driven by rapid economic growth in the Galápagos, the effects of introduced species have accelerated and severely threatened these iconic birds. The critically endangered mangrove finch (Camarhynchus heliobates) is now confined to three small mangroves on Isabela Island. During 2006–2009, we assessed its population status and monitored nesting success, both before and after rat poisoning. Population size was estimated at around only 100 birds for the two main breeding sites, with possibly 5–10 birds surviving at a third mangrove. Before rat control, 54 per cent of nests during incubation phase were predated with only 18 per cent of nests producing fledglings. Post-rat control, nest predation during the incubation phase fell to 30 per cent with 37 per cent of nests producing fledglings. During the nestling phase, infestation by larvae of the introduced parasitic fly (Philornis downsi) caused 14 per cent additional mortality. Using population viability analysis, we simulated the probability of population persistence under various scenarios of control and showed that with effective management of these invasive species, mangrove finch populations should start to recover. PMID:20194165

  14. Plant growth and the performance of mangrove wetland microcosms for mariculture effluent depuration.

    PubMed

    Su, Yung-Ming; Lin, Ying-Feng; Jing, Shuh-Ren; Hou, Ping-Chun Lucy

    2011-07-01

    This study established wetland microcosms that were either unplanted or planted in monoculture with native mangrove species in Taiwan (Avicennia marina, Rhizophora stylosa, and Lumnitzera racemosa) for the purpose of receiving high-salinity mariculture effluents; additionally, the microcosms operated at different hydraulic retention times (HRTs). Plant growth and the performance of the microcosms with respect to pollutant removal were investigated. The results showed that seedlings of all three mangrove species survived and grew sufficiently well under continuous flooding. The presence of mangroves consistently improved SS, BOD(5), and TP removal, particularly under short HRT conditions. The mangrove microcosms removed pollutants from the mariculture effluents with efficiencies of 5.7-27.1% (SS), 4.9-36.3% (BOD(5)), 18.7-29.9% (TP), 21.2-49.8% (NH(4)-N), and 5.4-37.7% (NO(x)-N). A. marina and L. racemosa were more tolerant of continuous flooding than R. stylosa. However, no species displayed consistently superior performance in decreasing all pollutant-related parameters investigated. For all pollutants, microcosms operating at a 2-d HRT exhibited a higher removal efficiency than those operating at a 0.5-d HRT. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Drifting propagules and receding swamps: genetic footprints of mangrove recolonization and dispersal along tropical coasts.

    PubMed

    Nettel, Alejandro; Dodd, Richard S

    2007-04-01

    Two issues that have captured the attention of tropical plant evolutionary biologists in recent years are the relative role of long distance dispersal (LDD) over vicariance in determining plant distributions and debate about the extent that Quaternary climatic changes affected tropical species. Propagules of some mangrove species are assumed to be capable of LDD due to their ability to float and survive for long periods of time in salt water. Mangrove species responded to glaciations with a contraction of their range. Thus, widespread mangrove species are an ideal system to study LDD and recolonization in the tropics. We present phylogenetic and phylogeographic analyses based on internal transcribed spacers region (ITS) sequences, chloroplast DNA (cpDNA), and amplified fragment length polymorphisms (AFLPs) of genomic DNA that demonstrate recent LDD across the Atlantic, rejecting the hypothesis of vicariance for the widespread distribution of the black mangrove (Avicennia germinans). Northern latitude populations likely became extinct during the late Quaternary due to frosts and aridification; these locations were recolonized afterward from southern populations. In some low latitude regions populations went extinct or were drastically reduced during the Quaternary because of lack of suitable habitat as sea levels changed. Our analyses show that low latitude Pacific populations of A. germinans harbor more diversity and reveal deeper divergence than Atlantic populations. Implications for our understanding of phylogeography of tropical species are discussed.

  16. Habitat fragmentation leads to reduced pollinator visitation, fruit production and recruitment in urban mangrove forests.

    PubMed

    Hermansen, Tyge D; Minchinton, Todd E; Ayre, David J

    2017-09-08

    Mangrove forests worldwide undergo anthropogenic fragmentation that may threaten their existence, and yet there have been few tests of the effects of fragmentation on demographic processes critical for mangrove regeneration. Predicting the effects of habitat fragmentation on mangroves is problematic as pollinators may move more freely across water than terrestrial habitat, and propagules can be widely dispersed by water. Here, within each of two estuaries, we compared pollinator diversity and activity, reproductive effort and output, and rates of recruitment for sets of three large (>1500 trees), medium (300-500) and small (<50) stands. As predicted, most measures of reproductive activity and success were inversely related to stand size with large stands typically producing significantly more and larger fruit, and significantly more seedlings. Most strikingly, we found the effect of fragmentation on the abundance of pollinators (honeybees), the production and quality of fruit and the survival rate of seedlings to be similar, showing significant reduction of recruitment in small stands. This study provides the first rigorous evidence that recruitment of mangroves, like for many terrestrial plants, is negatively impacted by habitat fragmentation. From a management perspective, we argue that in the short term our data imply the importance of conserving the largest possible stands. However, additional work is needed to determine (1) the proportion of recruits within small stands that originate within large stands, (2) how seedling performance varies with fruit size and genotype, and (3) how seedling size and performance vary with the abundance and diversity of pollen.

  17. Natural and cultured populations of the mangrove oyster Saccostrea palmula from Sinaloa, Mexico, infected by Perkinsus marinus.

    PubMed

    Cáceres-Martínez, Jorge; Ortega, Mauricio García; Vásquez-Yeomans, Rebeca; García, Teresa de Jesús Pineda; Stokes, Nancy A; Carnegie, Ryan B

    2012-07-01

    The mangrove oyster Saccostrea palmula coexists with the pleasure oyster Crassostrea corteziensis in coastal lagoons of northwest Mexico. Recent discovery of Perkinsus marinus infecting the pleasure oyster in the region prompted evaluation of S. palmula as an alternative P. marinus host. An analysis to determine the possible presence of P. marinus in natural and cultured populations of S. palmula at four coastal lagoons in Sinaloa, Mexico was carried out during October-November 2010. Tissues from apparently healthy S. palmula were evaluated using Ray's fluid thioglycollate method (RFTM), which revealed a Perkinsus sp. to be present in all four locations at 6.7-20.0% prevalence. Histopathological analysis of these specimens showed tissue alterations and parasite forms consistent with moderate P. marinus infection, which was confirmed by ribosomal non-transcribed spacer (NTS)-based PCR assays on DNA samples from oysters positive by RFTM and histology. DNA sequencing of amplified NTS fragments (307 bp) produced a sequence 98-100% similar to GenBank-deposited sequences of the NTS from P. marinus. Fluorescent in situ hybridization for Perkinsus spp. and P. marinus corroborated the PCR results, showing clear hybridization of P. marinus in host tissues. This is the first record of P. marinus infecting a species from genus Saccostrea and the first record of the parasite from coastal lagoons in Sinaloa, Mexico.

  18. Floods and mangrove forests, friends or foes? Perceptions of relationships and risks in Cameroon coastal mangroves

    NASA Astrophysics Data System (ADS)

    Munji, Cecilia A.; Bele, Mekou Y.; Idinoba, Monica E.; Sonwa, Denis J.

    2014-03-01

    Faced with the growing influence of climate change on climate driven perturbations such as flooding and biodiversity loss, managing the relationship between mangroves and their environment has become imperative for their protection. Hampering this is the fact that the full scope of the threats faced by specific mangrove forests is not yet well documented. Amongst some uncertainties is the nature of the relationship/interaction of mangroves with climate driven perturbations prevalent in their habitat such as coastal floods. We investigated the relationship between coastal flooding and mangrove forest stabilization, identify perceptions of flood risk and responses to offset identified effects. Random household surveys were carried out within four communities purposively sampled within the Cap Cameroon. Coastal changes were investigated over a period of 43 years (1965-2008). Seasonal flooding improved access to mangrove forests and hence promoted their exploitation for non-timber forest products (NTFPs) such as fuel wood and mangrove poles. 989 ha of mangrove forests were estimated to be lost over a period of 43 years in Cap Cameroon with implications on forest resources base, ecosystem stability, and livelihoods. Alternative livelihood activities were found to be carried out to moderate interruptions in fishing, with associated implications for mangrove forest dynamics. Respondents were of the opinion that risks associated with floods and mangrove deforestation will pose a major challenge for sustainable management of mangroves. These locally relevant perceptions and responses should however enable the identification of pertinent needs, challenges and opportunities to inform and orient effective decision-making, and to facilitate the development and participation in adaptive management strategies.

  19. Airborne Laser Scanning Quantification of Disturbances from Hurricanes and Lightning Strikes to Mangrove Forests in Everglades National Park, USA

    PubMed Central

    Zhang, Keqi; Simard, Marc; Ross, Michael; Rivera-Monroy, Victor H.; Houle, Patricia; Ruiz, Pablo; Twilley, Robert R.; Whelan, Kevin R. T.

    2008-01-01

    Airborne light detection and ranging (LIDAR) measurements derived before and after Hurricanes Katrina and Wilma (2005) were used to quantify the impact of hurricanes and lightning strikes on the mangrove forest at two sites in Everglades National Park (ENP). Analysis of LIDAR measurements covering 61 and 68 ha areas of mangrove forest at the Shark River and Broad River sites showed that the proportion of high tree canopy detected by the LIDAR after the 2005 hurricane season decreased significantly due to defoliation and breakage of branches and trunks, while the proportion of low canopy and the ground increased drastically. Tall mangrove forests distant from tidal creeks suffered more damage than lower mangrove forests adjacent to the tidal creeks. The hurricanes created numerous canopy gaps, and the number of gaps per square kilometer increased from about 400∼500 to 4000 after Katrina and Wilma. The total area of gaps in the forest increased from about 1∼2% of the total forest area to 12%. The relative contribution of hurricanes to mangrove forest disturbance in ENP is at least 2 times more than that from lightning strikes. However, hurricanes and lightning strikes disturb the mangrove forest in a related way. Most seedlings in lightning gaps survived the hurricane impact due to the protection of trees surrounding the gaps, and therefore provide an important resource for forest recovery after the hurricane. This research demonstrated that LIDAR is an effective remote sensing tool to quantify the effects of disturbances such as hurricanes and lightning strikes in the mangrove forest. PMID:27879821

  20. Airborne Laser Scanning Quantification of Disturbances from Hurricanes and Lightning Strikes to Mangrove Forests in Everglades National Park, USA.

    PubMed

    Zhang, Keqi; Simard, Marc; Ross, Michael; Rivera-Monroy, Victor H; Houle, Patricia; Ruiz, Pablo; Twilley, Robert R; Whelan, Kevin

    2008-04-01

    Airborne light detection and ranging (LIDAR) measurements derived before and after Hurricanes Katrina and Wilma (2005) were used to quantify the impact of hurricanes and lightning strikes on the mangrove forest at two sites in Everglades National Park (ENP). Analysis of LIDAR measurements covering 61 and 68 ha areas of mangrove forest at the Shark River and Broad River sites showed that the proportion of high tree canopy detected by the LIDAR after the 2005 hurricane season decreased significantly due to defoliation and breakage of branches and trunks, while the proportion of low canopy and the ground increased drastically. Tall mangrove forests distant from tidal creeks suffered more damage than lower mangrove forests adjacent to the tidal creeks. The hurricanes created numerous canopy gaps, and the number of gaps per square kilometer increased from about 400~500 to 4000 after Katrina and Wilma. The total area of gaps in the forest increased from about 1~2% of the total forest area to 12%. The relative contribution of hurricanes to mangrove forest disturbance in ENP is at least 2 times more than that from lightning strikes. However, hurricanes and lightning strikes disturb the mangrove forest in a related way. Most seedlings in lightning gaps survived the hurricane impact due to the protection of trees surrounding the gaps, and therefore provide an important resource for forest recovery after the hurricane. This research demonstrated that LIDAR is an effective remote sensing tool to quantify the effects of disturbances such as hurricanes and lightning strikes in the mangrove forest.

  1. Predicting future mangrove forest migration in the Everglades under rising sea level

    USGS Publications Warehouse

    Doyle, Thomas W.

    2003-01-01

    Mangroves are highly productive ecosystems that provide valued habitat for fish and shorebirds. Mangrove forests are universally composed of relatively few tree species and a single overstory strata. Three species of true mangroves are common to intertidal zones of the Caribbean and Gulf of Mexico Coast, namely, black mangrove (Avicennia germinans), white mangrove (Laguncularia racemosa), and red mangrove (Rhizophora mangle). Mangrove forests occupy intertidal settings of the coastal margin of the Everglades along the southwest tip of the Florida peninsula (fig. 1).

  2. Transport of marine fish larvae to Saroma-ko Lagoon (Hokkaido, Japan) in relation to the availability of zooplankton prey under the winter ice cover

    NASA Astrophysics Data System (ADS)

    Fortier, Martin; Fortier, Louis

    1997-02-01

    To assess the importance of ice-covered Saroma-ko Lagoon as a winter nursery area for young fish spawned offshore, we monitored the recruitment of marine fish larvae from the Sea of Okhotsk to the lagoon as well as the availability of larval fish prey under the ice cover from 24 February to 23 March 1992. Sand lance ( Ammodytes sp.) and walleye pollock ( Theragra chalcogramma) larvae recruited to the lagoon on flood tide whereas snake prickleback ( Lumpenus sagitta) larvae were exported to the Sea of Okhotsk on ebb. Before the ice breakup, ice microalgae made up the bulk of the microalgal biomass in the lagoon. The production and release of ice algae did not trigger the maturation of the late copepodite stages of copepods, and the proportion of adult females in the copepod assemblage remained low. The production of copepod nauplii (the main prey of fish larvae) under the ice was probably insufficient to insure suitable feeding and growth of fish larvae entering the lagoon in winter. Sand lance larvae, the most abundant species to colonize the lagoon in February-March, had to survive for nearly two months at low food abundance. Based on our results, the importance of Saroma-ko Lagoon as a winter nursery area for fish larvae appears negligible.

  3. The role of mangroves in attenuating storm surges

    NASA Astrophysics Data System (ADS)

    Zhang, Keqi; Liu, Huiqing; Li, Yuepeng; Xu, Hongzhou; Shen, Jian; Rhome, Jamie; Smith, Thomas J.

    2012-05-01

    Field observations and numerical simulations indicate that the 6-to-30-km-wide mangrove forest along the Gulf Coast of South Florida effectively attenuated storm surges from a Category 3 hurricane, Wilma, and protected the inland wetland by reducing an inundation area of 1800 km2 and restricting surge inundation inside the mangrove zone. The surge amplitude decreases at a rate of 40-50 cm/km across the mangrove forest and at a rate of 20 cm/km across the areas with a mixture of mangrove islands with open water. In contrast, the amplitudes of storm surges at the front of the mangrove zone increase by about 10-30% because of the "blockage" of mangroves to surge water, which can cause greater impacts on structures at the front of mangroves than the case without mangroves. The mangrove forest can also protect the wetlands behind the mangrove zone against surge inundation from a Category 5 hurricane with a fast forward speed of 11.2 m/s (25 mph). However, the forest cannot fully attenuate storm surges from a Category 5 hurricane with a slow forward speed of 2.2 m/s (5 mph) and reduced surges can still affect the wetlands behind the mangrove zone. The effects of widths of mangrove zones on reducing surge amplitudes are nonlinear with large reduction rates (15-30%) for initial width increments and small rates (<5%) for subsequent width increments.

  4. The role of mangroves in attenuating storm surges

    USGS Publications Warehouse

    Zhang, Keqi; Liu, Huiqing; Li, Yuepeng; Xu, Hongzhou; Shen, Jian; Rhome, Jamie; Smith, J.

    2012-01-01

    Field observations and numerical simulations indicate that the 6-to-30-km-wide mangrove forest along the Gulf Coast of South Florida effectively attenuated stormsurges from a Category 3 hurricane, Wilma, and protected the inland wetland by reducing an inundation area of 1800 km2 and restricting surge inundation inside the mangrove zone. The surge amplitude decreases at a rate of 40–50 cm/km across the mangrove forest and at a rate of 20 cm/km across the areas with a mixture of mangrove islands with open water. In contrast, the amplitudes of stormsurges at the front of the mangrove zone increase by about 10–30% because of the "blockage" of mangroves to surge water, which can cause greater impacts on structures at the front of mangroves than the case without mangroves. The mangrove forest can also protect the wetlands behind the mangrove zone against surge inundation from a Category 5 hurricane with a fast forward speed of 11.2 m/s (25 mph). However, the forest cannot fully attenuate stormsurges from a Category 5 hurricane with a slow forward speed of 2.2 m/s (5 mph) and reduced surges can still affect the wetlands behind the mangrove zone. The effects of widths of mangrove zones on reducing surge amplitudes are nonlinear with large reduction rates (15–30%) for initial width increments and small rates (<5%) for subsequent width increments.

  5. Rapid seawater circulation through animal burrows in mangrove forests - A significant source of saline groundwater to the tropical coastal ocean

    NASA Astrophysics Data System (ADS)

    Clark, J. F.; Stieglitz, T. C.; Hancock, G. J.

    2010-12-01

    A common approach for quantifying rates of submarine groundwater discharge (SGD) to the coastal ocean is to use geochemical tracers that are part of the U- and Th-decay chains such as Rn-222 and short lived radium isotopes. These radionuclides are naturally enriched in groundwater relative to seawater and have well understood chemistries within the marine environment. They occur in both fresh (continental) and saline (marine) groundwaters and thus the water source is often ambiguous. Stieglitz (2005, Marine Pollution Bulletin 51, 51-59) has shown that some coastal areas within the Great Barrier Reef (GBR) lagoon (Australia) are enriched in the SGD tracer, Rn-222; he attributed this to four possible processes including the tidal flushing of mangrove forest floors. Here, we present a detailed investigation into the tidal circulation of seawater through animal burrows using Rn-222 and isotopes of radium in the Coral Creek mangrove forest, Hinchinbrook Island, Queensland, Australia. The study was conducted at the end of the dry season in a creek with no freshwater inputs. Significant export of radionuclides and salt from the forest into the creek indicates continuous tidally driven circulation through the burrows. Results demonstrate that the forest sediment is efficiently flushed, with a water flux of about 30 L/m2/ day of forest floor, which is equivalent to flushing about 10% of the total burrow volume per tidal cycle. Annual average circulation flux through mangrove forest floors are of the same order as annual river discharge in the central GBR. However, unlike the river discharge, the tidal circulation should be relatively stable throughout the year. This work documents the importance of animal burrows in maintaining productive sediments in these systems, and illustrates the physical process that supports large exports of organic and inorganic matter from mangrove forests to the coastal zone. It also illustrates the importance of considering saline groundwater

  6. 2H/1H fractionation in lipids of the mangrove Bruguiera gymnorhiza increases with salinity in marine lakes of Palau

    NASA Astrophysics Data System (ADS)

    Ladd, S. Nemiah; Sachs, Julian P.

    2017-05-01

    Hydrogen isotope ratios (2H/1H or D/H) of sedimentary mangrove lipid biomarkers can be exploited as a quantitative proxy of past salinity and water isotopes. This approach is based on the observation that apparent 2H/1H fractionation between surface water and mangrove leaf lipids increases with surface water salinity. In order to better understand the mechanisms responsible for this empirical relationship, we analyzed the isotopic composition of surface water, xylem water, leaf water and leaf lipids from Bruguiera gymnorhiza mangroves growing around eleven marine lakes and a lagoon on the rock islands of Palau, spanning a salinity range of 5-32 parts per thousand (ppt). Net fractionation increased with increasing salinity for both nC31-alkane (0.7 ± 0.1‰ ppt-1) and for the pentacyclic triterpenoid lupeol (0.5 ± 0.2‰ ppt-1). These trends could not be attributed to changes in biosynthetic fractionation with salinity, but seem more likely to be due to increasing disequilibrium between xylem water and water vapor as salinity increases. In Palau's humid climate, this most likely causes leaf water to become less 2H-enriched relative to surface water and to xylem water as salinity increases. This supposition is supported not only by measurements of leaf water 2H enrichment, but also by the correlation (R2 = 0.66) between leaf water isotopes and those of rain water, which are assumed to be in equilibrium with water vapor isotopes, and by the dependence of leaf water isotopes on water vapor isotopes in a Péclet-modified Craig-Gordon model. These results should inform the application of sedimentary mangrove lipid hydrogen isotope ratios to infer past hydroclimatic changes.

  7. The Lagoon at Caroline/Millennium Atoll, Republic of Kiribati: Natural History of a Nearly Pristine Ecosystem

    PubMed Central

    Barott, Katie L.; Caselle, Jennifer E.; Dinsdale, Elizabeth A.; Friedlander, Alan M.; Maragos, James E.; Obura, David; Rohwer, Forest L.; Sandin, Stuart A.; Smith, Jennifer E.; Zgliczynski, Brian

    2010-01-01

    A series of surveys were carried out to characterize the physical and biological parameters of the Millennium Atoll lagoon during a research expedition in April of 2009. Millennium is a remote coral atoll in the Central Pacific belonging to the Republic of Kiribati, and a member of the Southern Line Islands chain. The atoll is among the few remaining coral reef ecosystems that are relatively pristine. The lagoon is highly enclosed, and was characterized by reticulate patch and line reefs throughout the center of the lagoon as well as perimeter reefs around the rim of the atoll. The depth reached a maximum of 33.3 m in the central region of the lagoon, and averaged between 8.8 and 13.7 m in most of the pools. The deepest areas were found to harbor large platforms of Favia matthaii, which presumably provided a base upon which the dominant corals (Acropora spp.) grew to form the reticulate reef structure. The benthic algal communities consisted mainly of crustose coralline algae (CCA), microfilamentous turf algae and isolated patches of Halimeda spp. and Caulerpa spp. Fish species richness in the lagoon was half of that observed on the adjacent fore reef. The lagoon is likely an important nursery habitat for a number of important fisheries species including the blacktip reef shark and Napoleon wrasse, which are heavily exploited elsewhere around the world but were common in the lagoon at Millennium. The lagoon also supports an abundance of giant clams (Tridacna maxima). Millennium lagoon provides an excellent reference of a relatively undisturbed coral atoll. As with most coral reefs around the world, the lagoon communities of Millennium may be threatened by climate change and associated warming, acidification and sea level rise, as well as sporadic local resource exploitation which is difficult to monitor and enforce because of the atoll's remote location. While the remote nature of Millennium has allowed it to remain one of the few nearly pristine coral reef

  8. The lagoon at Caroline/Millennium atoll, Republic of Kiribati: natural history of a nearly pristine ecosystem.

    PubMed

    Barott, Katie L; Caselle, Jennifer E; Dinsdale, Elizabeth A; Friedlander, Alan M; Maragos, James E; Obura, David; Rohwer, Forest L; Sandin, Stuart A; Smith, Jennifer E; Zgliczynski, Brian

    2010-06-03

    A series of surveys were carried out to characterize the physical and biological parameters of the Millennium Atoll lagoon during a research expedition in April of 2009. Millennium is a remote coral atoll in the Central Pacific belonging to the Republic of Kiribati, and a member of the Southern Line Islands chain. The atoll is among the few remaining coral reef ecosystems that are relatively pristine. The lagoon is highly enclosed, and was characterized by reticulate patch and line reefs throughout the center of the lagoon as well as perimeter reefs around the rim of the atoll. The depth reached a maximum of 33.3 m in the central region of the lagoon, and averaged between 8.8 and 13.7 m in most of the pools. The deepest areas were found to harbor large platforms of Favia matthaii, which presumably provided a base upon which the dominant corals (Acropora spp.) grew to form the reticulate reef structure. The benthic algal communities consisted mainly of crustose coralline algae (CCA), microfilamentous turf algae and isolated patches of Halimeda spp. and Caulerpa spp. Fish species richness in the lagoon was half of that observed on the adjacent fore reef. The lagoon is likely an important nursery habitat for a number of important fisheries species including the blacktip reef shark and Napoleon wrasse, which are heavily exploited elsewhere around the world but were common in the lagoon at Millennium. The lagoon also supports an abundance of giant clams (Tridacna maxima). Millennium lagoon provides an excellent reference of a relatively undisturbed coral atoll. As with most coral reefs around the world, the lagoon communities of Millennium may be threatened by climate change and associated warming, acidification and sea level rise, as well as sporadic local resource exploitation which is difficult to monitor and enforce because of the atoll's remote location. While the remote nature of Millennium has allowed it to remain one of the few nearly pristine coral reef

  9. Trophic behaviour of juvenile reef fishes inhabiting interlinked mangrove-seagrass habitats in offshore mangrove islets.

    PubMed

    Vaslet, A; Phillips, D L; France, C A M; Feller, I C; Baldwin, C C

    2015-08-01

    Stable isotope (δ(13)C and δ(15)N) and gut content analyses were used to investigate size-related feeding habits of four reef fishes (the beaugregory Stegastes leucostictus, the french grunt Haemulon flavolineatum, the schoolmaster snapper Lutjanus apodus and the yellowtail snapper Ocyurus chrysurus) inhabiting an offshore (non-estuarine) mangrove islet off Belize, Central America. Comparisons of isotopic niche space and Schoener diet similarity index suggested a low to moderate degree of niche overlap between fish size groups. The δ(13)C gradient between mangrove and seagrass prey as well as results of Bayesian mixing models revealed that sampled fishes relied mostly on seagrass prey items. Only small and large juveniles of the carnivorous species L. apodus derived a part of their diet from mangroves by targeting mangrove-associated Grapsidae crabs and fish prey, respectively. Isotopic niche shifts were particularly obvious for carnivorous fishes that ingested larger prey items (Xanthidae crabs and fishes) during their ontogeny. The utilization of mangrove food resources is less than expected and depends on the ecology and life history of the fish species considered. This research highlights that mangrove-derived carbon contributed relatively little to the diets of four fish taxa from an offshore mangrove islet.

  10. [Actinomycetes from mangrove and their secondary metabolites].

    PubMed

    Hong, Kui

    2013-11-04

    Mangroves are woody plants located in tropical and subtropical intertidal coastal regions. Driven by the discovery of novel natural products from marine environment, mangrove is becoming a hot spot for actinomycetes resources collection and secondary metabolites (natural products) identification as well as their biosynthesis mechanism investigation. Salinaspora A produced by a Salinispora strain isolated from Bahamas mangrove environment, is in the first clinical trial. Till the time of writing this paper, 24 genera of 11 families and 8 suborders under the actinomycetale have been reported from mangrove, among which 3 are new genera, and 31 are new species. At the same time, secondary metabolites were identified from the mangrove actinomycetes culture, including alkanoids and quinines, azalomycins, antimycins, bezamides and quinazolines, divergolides, indole derivatives, kandenols, macrocyclic dilactones, and the attractive structures, such as the Streptocarbazoles, the multicyclic indolsesquiterpenes, and xiamycin presented unique structures. Their biosynthetic mechanism has also been investigated. Most of the metabolites were isolated from streptomycetes, with a few from Micromonospora and Saccharopolyspora.

  11. Fatty acids in an estuarine mangrove ecosystem.

    PubMed

    Alikunhi, Nabeel M; Narayanasamy, Rajendran; Kandasamy, Kathiresan

    2010-06-01

    Fatty acids have been successfully used to trace the transfer of organic matter in coastal and estuarine food webs. To delineate these web connections, fatty acid profiles were analyzed in species of microbes (Azotobacter vinelandii, and Lactobacillus xylosus), prawns (Metapenaeus monoceros and Macrobrachium rosenbergii) and finfish (Mugil cephalus), that are associated with decomposing leaves of two mangrove species, Rhizophora apiculata and Avicennia marina. The fatty acids, except long chain fatty acids, exhibit changes during decomposition of mangrove leaves with a reduction of saturated fatty acids and an increase of monounsaturated fatty acids. The branched fatty acids are absent in undecomposed mangrove leaves, but present significantly in the decomposed leaves and in prawns and finfish, representing an important source for them. This revealed that the microbes are dominant producers that contribute significantly to the fishes and prawns in the mangrove ecosystem. This work has proved the fatty acid biomarkers as an effective tool for identifying the trophic interactions among dominant producers and consumers in this mangrove.

  12. Regulation of water balance in mangroves

    PubMed Central

    Reef, Ruth; Lovelock, Catherine E.

    2015-01-01

    Background Mangroves are a group of highly salt-tolerant woody plants. The high water use efficiency of mangroves under saline conditions suggests that regulation of water transport is a crucial component of their salinity tolerance. Scope This review focuses on the processes that contribute to the ability of mangroves to maintain water uptake and limit water loss to the soil and the atmosphere under saline conditions, from micro to macro scales. These processes include: (1) efficient filtering of the incoming water to exclude salt; (2) maintenance of internal osmotic potentials lower than that of the rhizosphere; (3) water-saving properties; and (4) efficient exploitation of less-saline water sources when these become available. Conclusions Mangroves are inherently plastic and can change their structure at the root, leaf and stand levels in response to salinity in order to exclude salt from the xylem stream, maintain leaf hydraulic conductance, avoid cavitation and regulate water loss (e.g. suberization of roots and alterations of leaf size, succulence and angle, hydraulic anatomy and biomass partitioning). However, much is still unknown about the regulation of water uptake in mangroves, such as how they sense and respond to heterogeneity in root zone salinity, the extent to which they utilize non-stomatally derived CO2 as a water-saving measure and whether they can exploit atmospheric water sources. PMID:25157072

  13. Restoration of mangrove plantations and colonisation by native species in Leizhou bay, South China

    Treesearch

    Hai Ren; Shuguang Jian; Hongfang Lu; Qianmei Zhang; Weijun Shen; Weidong Han; Zuoyun Yin; Qinfeng Guo

    2008-01-01

    To examine the natural colonisation of native mangrove species into remediated exotic mangrove stands in Leizhou Bay, South China, we compared soil physical–chemical properties, community structure and recruitments of barren mangrove areas, native mangrove species plantations, and exotic mangrove species—Sonneratia apetala Buch.Ham—between plantations and natural...

  14. Integrated mangrove-shrimp cultivation: Potential for blue carbon sequestration.

    PubMed

    Ahmed, Nesar; Thompson, Shirley; Glaser, Marion

    2017-10-04

    Globally, shrimp farming has had devastating effects on mangrove forests. However, mangroves are the most carbon-rich forests, with blue carbon (i.e., carbon in coastal and marine ecosystems) emissions seriously augmented due to devastating effects on mangrove forests. Nevertheless, integrated mangrove-shrimp cultivation has emerged as a part of the potential solution to blue carbon emissions. Integrated mangrove-shrimp farming is also known as organic aquaculture if deforested mangrove area does not exceed 50% of the total farm area. Mangrove destruction is not permitted in organic aquaculture and the former mangrove area in parts of the shrimp farm shall be reforested to at least 50% during a period of maximum 5 years according to Naturland organic aquaculture standards. This article reviews integrated mangrove-shrimp cultivation that can help to sequester blue carbon through mangrove restoration, which can be an option for climate change mitigation. However, the adoption of integrated mangrove-shrimp cultivation could face several challenges that need to be addressed in order to realize substantial benefits from blue carbon sequestration.

  15. How is Shrimp Aquaculture Transforming Coastal Livelihoods and Lagoons in Estero Real, Nicaragua?: The Need to Integrate Social-Ecological Research and Ecosystem-Based Approaches

    NASA Astrophysics Data System (ADS)

    Benessaiah, Karina; Sengupta, Raja

    2014-08-01

    Ecosystem-based approaches to aquaculture integrate environmental concerns into planning. Social-ecological systems research can improve this approach by explicitly relating ecological and social dynamics of change at multiple scales. Doing so requires not only addressing direct effects of aquaculture but also considering indirect factors such as changes in livelihood strategies, governance dynamics, and power relations. We selected the community of Puerto Morazán, Nicaragua as a case study to demonstrate how the introduction of small-scale aquaculture radically transformed another key livelihood activity, lagoon shrimp fishing, and the effects that these changes have had on lagoons and the people that depend on them. We find that shrimp aquaculture played a key role in the collapse, in the 1990s, of an existing lagoon common-property management. Shrimp aquaculture-related capital enabled the adoption of a new fishing technique that not only degraded lagoons but also led to their gradual privatization. The existence of social ties between small-scale shrimp farmers and other community members mitigated the impacts of privatization, illustrating the importance of social capital. Since 2008, community members are seeking to communally manage the lagoons once again, in response to degraded environmental conditions and a consolidation of the shrimp industry at the expense of smaller actors. This research shows that shrimp aquaculture intersects with a complex set of drivers, affecting not only how ecosystems are managed but also how they are perceived and valued. Understanding these social-ecological dynamics is essential to implement realistic policies and management of mangrove ecosystems and address the needs of resource-dependent people.

  16. How is shrimp aquaculture transforming coastal livelihoods and lagoons in Estero Real, Nicaragua? The need to integrate social-ecological research and ecosystem-based approaches.

    PubMed

    Benessaiah, Karina; Sengupta, Raja

    2014-08-01

    Ecosystem-based approaches to aquaculture integrate environmental concerns into planning. Social-ecological systems research can improve this approach by explicitly relating ecological and social dynamics of change at multiple scales. Doing so requires not only addressing direct effects of aquaculture but also considering indirect factors such as changes in livelihood strategies, governance dynamics, and power relations. We selected the community of Puerto Morazán, Nicaragua as a case study to demonstrate how the introduction of small-scale aquaculture radically transformed another key livelihood activity, lagoon shrimp fishing, and the effects that these changes have had on lagoons and the people that depend on them. We find that shrimp aquaculture played a key role in the collapse, in the 1990s, of an existing lagoon common-property management. Shrimp aquaculture-related capital enabled the adoption of a new fishing technique that not only degraded lagoons but also led to their gradual privatization. The existence of social ties between small-scale shrimp farmers and other community members mitigated the impacts of privatization, illustrating the importance of social capital. Since 2008, community members are seeking to communally manage the lagoons once again, in response to degraded environmental conditions and a consolidation of the shrimp industry at the expense of smaller actors. This research shows that shrimp aquaculture intersects with a complex set of drivers, affecting not only how ecosystems are managed but also how they are perceived and valued. Understanding these social-ecological dynamics is essential to implement realistic policies and management of mangrove ecosystems and address the needs of resource-dependent people.

  17. Ecology of the mangroves of south Florida: a community profile

    SciTech Connect

    Odum, W.E.; McIvor, C.C.; Smith, T.J. III

    1982-01-01

    A detailed description is given of the community structure and ecosystem processes of the mangrove forests of south Florida. This description is based upon a compilation of data and hypotheses from published and unpublished sources. Information covered ranges from details of mangrove distribution, primary production, and diseases to asepcts of reproduction, biomass partitioning, and adaptations to stress. Mangrove ecosystems are considered in terms of zonation, succession, litter fall and decomposition, carbon export, and energy flow. Most of the components of mangrove communities are cataloged and discussed; these include mircoorganisms, plants other than mangroves, invertebrates, fishes, reptiles, amphibians, birds, and mammals. Finally, two sections summarize the value of mangrove ecosystems to man and present ways to manage this type of habitat. It is concluded that mangrove forests, which cover between 430,000 and 500,000 acres (174,000 to 202,000 ha) in Florida, are a resource of great value and should be protected and preserved wherever possible.

  18. [Natural regeneration response in mangroves of the gulf of Urabá (Colombia) to the environmental and intra-annual climate variability].

    PubMed

    Hoyos, Róssalyn; Urrego, Ligia Estela; Lema, Alvaro

    2013-09-01

    The natural regeneration process allows the mangrove forests remain over time. Both, biological and physical factors can affect the establishment and early stages along the development of trees. This study examined the response of natural regeneration of mangroves in the Turbo River delta and El Uno bay (Urabá Gulf, Colombia) to intra-annual environmental variability. We quantified mortality, survival and recruitment of seedlings of three mangrove species, seasonally during one year, in 72 semi-permanent sub-plots of 1 m2. In the sub-plots, the total height and the diameter at the base of the stem of all mangrove seedlings with basal diameter less than 2.5cm were measured. Damage by herbivores was also recorded to each seedling. While Laguncularia racemosa recorded the highest rates of mortality, Rhizophora mangle showed the highest survival rate during the study period, although Avicennia germinans dominated the natural regeneration. Through a Redundancy Analysis these processes were associated to environmental variables such as: Direct Site Factor-DSF (sunlight), sediments input rate, herbivory, distances from mangroves to the river, to inner lakes, and to the coastline. These variables explained 43% of the natural regeneration variation; sedimentation rate was the most important variable, while light was very representative for the R. mangle survival. Based on historical records of precipitation, Turbo River flow rate and associated sediment loads, it was established that during the highest precipitation peak, the survival of all species decreases and during the dry season, when the conditions of flooding and sediments input were lower, it was improved. The results indicated that the sediments input rates and sunlight play an important role in the survival of natural regeneration of evaluated mangrove species.

  19. Nutrient controls on biocomplexity of mangrove ecosystems

    USGS Publications Warehouse

    McKee, Karen L.

    2004-01-01

    Mangrove forests are important coastal ecosystems that provide a variety of ecological and societal services. These intertidal, tree-dominated communities along tropical coastlines are often described as “simple systems,” compared to other tropical forests with larger numbers of plant species and multiple understory strata; however, mangrove ecosystems have complex trophic structures, and organisms exhibit unique physiological, morphological, and behavioral adaptations to environmental conditions characteristic of the land-sea interface. Biogeochemical functioning of mangrove forests is also controlled by interactions among the microbial, plant, and animal communities and feedback linkages mediated by hydrology and other forcing functions. Scientists with the U.S. Geological Survey (USGS) at the National Wetlands Research Center are working to understand more fully the impact of nutrient variability on these delicate and important ecosystems.

  20. Nutrient Enrichment Increases Mortality of Mangroves

    PubMed Central

    Lovelock, Catherine E.; Ball, Marilyn C.; Martin, Katherine C.; C. Feller, Ilka

    2009-01-01

    Nutrient enrichment of the coastal zone places intense pressure on marine communities. Previous studies have shown that growth of intertidal mangrove forests is accelerated with enhanced nutrient availability. However, nutrient enrichment favours growth of shoots relative to roots, thus enhancing growth rates but increasing vulnerability to environmental stresses that adversely affect plant water relations. Two such stresses are high salinity and low humidity, both of which require greater investment in roots to meet the demands for water by the shoots. Here we present data from a global network of sites that documents enhanced mortality of mangroves with experimental nutrient enrichment at sites where high sediment salinity was coincident with low rainfall and low humidity. Thus the benefits of increased mangrove growth in response to coastal eutrophication is offset by the costs of decreased resilience due to mortality during drought, with mortality increasing with soil water salinity along climatic gradients. PMID:19440554

  1. Microplastics in Singapore's coastal mangrove ecosystems.

    PubMed

    Nor, Nur Hazimah Mohamed; Obbard, Jeffrey Philip

    2014-02-15

    The prevalence of microplastics was studied in seven intertidal mangroves habitats of Singapore. Microplastics were extracted from mangrove sediments via a floatation method, and then counted and categorized according to particle shape and size. Representative microplastics from Berlayar Creek, Sungei Buloh, Pasir Ris and Lim Chu Kang were isolated for polymer identification using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. Microplastics were identified in all seven habitats, with the highest concentration found in sediments at Lim Chu Kang in the northwest of Singapore. The majority of microplastics were fibrous and smaller than 20 μm. A total of four polymer types were identified, including polyethylene, polypropylene, nylon and polyvinyl chloride. The relationship between abundance of microplastics and sediment grain size was also investigated, but no relationship was apparent. The presence of microplastics is likely due to the degradation of marine plastic debris accumulating in the mangroves.

  2. Changes in biotic and abiotic processes following mangrove clearing

    NASA Astrophysics Data System (ADS)

    Granek, Elise; Ruttenberg, Benjamin I.

    2008-12-01

    Mangrove forests, important tropical coastal habitats, are in decline worldwide primarily due to removal by humans. Changes to mangrove systems can alter ecosystem properties through direct effects on abiotic factors such as temperature, light and nutrient supply or through changes in biotic factors such as primary productivity or species composition. Despite the importance of mangroves as transitional habitats between land and sea, little research has examined changes that occur when they are cleared. We examined changes in a number of biotic and abiotic factors following the anthropogenic removal of red mangroves ( Rhizophora mangle) in the Panamanian Caribbean, including algal biomass, algal diversity, algal grazing rates, light penetration, temperature, sedimentation rates and sediment organic content. In this first study examining multiple ecosystem-level effects of mangrove disturbance, we found that areas cleared of mangroves had higher algal biomass and richness than intact mangrove areas. This increase in algal biomass and richness was likely due to changes in abiotic factors (e.g. light intensity, temperature), but not biotic factors (fish herbivory). Additionally the algal and cyanobacterial genera dominating mangrove-cleared areas were rare in intact mangroves and included a number of genera that compete with coral for space on reefs. Interestingly, sedimentation rates did not differ between intact and cleared areas, but the sediments that accumulated in intact mangroves had higher organic content. These findings are the first to demonstrate that anthropogenic clearing of mangroves changes multiple biotic and abiotic processes in mangrove forests and that some of these changes may influence adjacent habitats such as coral reefs and seagrass beds. Additional research is needed to further explore the community and ecosystem-level effects of mangrove clearing and their influence on adjacent habitats, but it is clear that mangrove conservation is an

  3. Root biomechanics in Rhizophora mangle: anatomy, morphology and ecology of mangrove's flying buttresses.

    PubMed

    Méndez-Alonzo, Rodrigo; Moctezuma, Coral; Ordoñez, Víctor R; Angeles, Guillermo; Martínez, Armando J; López-Portillo, Jorge

    2015-04-01

    Rhizophora species of mangroves have a conspicuous system of stilt-like roots (rhizophores) that grow from the main stem and resemble flying buttresses. As such, the development of rhizophores can be predicted to be important for the effective transmission of dynamic loads from the top of the tree to the ground, especially where the substrate is unstable, as is often the case in the habitats where Rhizophora species typically grow. This study tests the hypothesis that rhizophore architecture in R. mangle co-varies with their proximity to the main stem, and with stem size and crown position. The allometry and wood mechanical properties of R. mangle (red mangrove) trees growing in a mangrove basin forest within a coastal lagoon in Mexico were compared with those of coexisting, non-buttressed mangrove trees of Avicennia germinans. The anatomy of rhizophores was related to mechanical stress due to crown orientation (static load) and to prevailing winds (dynamic load) at the study site. Rhizophores buttressed between 10 and 33 % of tree height. There were significant and direct scaling relationships between the number, height and length of rhizophores vs. basal area, tree height and crown area. Wood mechanical resistance was significantly higher in the buttressed R. mangle (modulus of elasticity, MOE = 18·1 ± 2 GPa) than in A. germinans (MOE = 12·1 ± 0·5 GPa). Slenderness ratios (total height/stem diameter) were higher in R. mangle, but there were no interspecies differences in critical buckling height. When in proximity to the main stem, rhizophores had a lower length/height ratio, higher eccentricity and higher xylem/bark and pith proportions. However, there were no directional trends with regard to prevailing winds or tree leaning. In comparison with A. germinans, a tree species with wide girth and flare at the base, R. mangle supports a thinner stem of higher mechanical resistance that is stabilized by rhizophores resembling flying

  4. Seasonal Berm Behavior on a Coastal Lagoon Pocket Beach

    NASA Astrophysics Data System (ADS)

    Harden, L.

    2011-12-01

    Coastal lagoon beaches are typically characterized by a seasonal berm that separates the lagoon mouth from the open ocean during summer months and is temporarily breached and eroded offshore as a result of higher wave energy during winter months. Seasonal morphodynamic changes on a coastal lagoon pocket beach in Santa Cruz, California were monitored from August 2010 to April 2011. Monthly total station GPS surveys were conducted on Younger Lagoon Reserve beach in conjunction with monthly grain size analyses. A time series comparison of beach profiles extracted from shore-normal transects reveals that the berm fronting the lagoon mouth did not erode with increasing wave energy during the winter months as expected, but either stayed fixed while the foreshore steepened or migrated horizontally across shore. Berm height is likely maintained by wave overtopping of the berm crest at the lagoon mouth during high tides or storm events. Foreshore steepening occurs in conjunction with an increase in coarse sediment fraction and is consistent with increasing wave energy and turbulent swash interaction. Cross-shore sediment transport in the foreshore fronting the lagoon mouth is likely enhanced by infiltration and exfiltration of water on the shoreface due to the position of the water table with respect to the maximum swash runup. Coastal lagoon beach berm behavior and the subsequent extent of lagoon-ocean mixing has important implications for coastal water quality and lagoon ecosystem dynamics.

  5. Ecosystem Development after Mangrove Wetland Creation: Plant-Soil Change across a 20-year Chronosequence

    EPA Science Inventory

    Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland loss. However, ecosystem development and functional equivalence in restored and created mangrove wetlands is poorly understood. We compared a 20-yr chrono...

  6. Ecosystem Development after Mangrove Wetland Creation: Plant-Soil Change across a 20-year Chronosequence

    EPA Science Inventory

    Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland loss. However, ecosystem development and functional equivalence in restored and created mangrove wetlands is poorly understood. We compared a 20-yr chrono...

  7. Threat of heavy metal contamination in eight mangrove plants from the Futian mangrove forest, China.

    PubMed

    He, Bei; Li, Ruili; Chai, Minwei; Qiu, Guoyu

    2014-06-01

    Mangrove plants play an important role in heavy metal maintenance in a mangrove ecosystem. To evaluate the characteristics of heavy metal contamination in the Futian mangrove forest, Shenzhen, China, eight heavy metals in mangrove sediments and plants were monitored, including essential elements such as Cu and Zn, and non-essential elements such as Cr, Ni, As, Cd, Pb and Hg. The results showed that the heavy metals exhibited the following scheme: Zn > As > Cu ≈ Cr > Pb > Ni > Cd ≈ Hg in sediment cores, among which Cd, As, Pb and Hg contents were nearly ten times higher than the background values. There was no significant difference in metal maintenance capability between native and exotic species. In mangrove plants' leaves and stems, concentrations of Cu, Zn and As were higher than other heavy metals. The low bioconcentration factors for most heavy metals, except for Cr, implied the limited ability of heavy metal accumulation by the plants. Mangrove plants seem to develop some degree of tolerance to Cr. The factor analysis implies that anthropogenic influences have altered metal mobility and bioavailability.

  8. Factors influencing the regeneration of the mangrove Bruguiera gymnorrhiza (L.) Lamk. on a tropical Pacific island

    USGS Publications Warehouse

    Krauss, K.W.; Allen, J.A.

    2003-01-01

    Mangrove swamps occupy approximately two-thirds of the shoreline on Kosrae, Federated States of Micronesia (FSM), and also border the island's most populated areas. Kosraeans depend on mangrove swamps for a supply of wood to support a growing handicraft industry, for a dependable source of fuelwood, and for habitat to support the harvest of fish and mangrove crabs. One of the more prominent mangrove species on Kosrae is Bruguiera gymnorrhiza, yet it is not the most preferred species for carving or cooking. To evaluate B. gymnorrhiza's persistence in the intertidal and to develop a better understanding of factors influencing its regeneration, we investigated predispersal insect colonization of propagules, postdispersal propagule predation by crabs, and the relative effects of natural and artificial shade, salinity, and tidal flooding on early tree seedling survival and growth. Predispersal insect colonization of propagules by boring insects was very high (93%), but the damage did not seem to influence seedling survival. Postdispersal predation of B. gymnorrhiza propagules by crabs was low (17%) and did not change in gap versus understory plots. Predation did vary by intertidal location (lower intertidal > middle intertidal = upper intertidal), with lower predation occurring in an intertidal location with a B. gymnorrhiza-dominated overstory. Shade and tidal inundation reduced seedling growth more than salinity in greenhouse investigations, but sunlight had less positive influence on seedling growth in the field. In general, regeneration and growth occurred successfully under a variety of conditions, indicating that none of the factors investigated serve as strong regulators to B. gymnorrhiza regeneration and early growth on Kosrae. ?? 2002 Elsevier Science B.V. All rights reserved.

  9. Bacterial structure and characterization of plant growth promoting and oil degrading bacteria from the rhizospheres of mangrove plants.

    PubMed

    do Carmo, Flávia Lima; dos Santos, Henrique Fragoso; Martins, Edir Ferreira; van Elsas, Jan Dirk; Rosado, Alexandre Soares; Peixoto, Raquel Silva

    2011-08-01

    Most oil from oceanic spills converges on coastal ecosystems, such as mangrove forests, which are threatened with worldwide disappearance. Particular bacteria that inhabit the rhizosphere of local plant species can stimulate plant development through various mechanisms; it would be advantageous if these would also be capable of degrading oil. Such bacteria may be important in the preservation or recuperation of mangrove forests impacted by oil spills. This study aimed to compare the bacterial structure, isolate and evaluate bacteria able to degrade oil and stimulate plant growth, from the rhizospheres of three mangrove plant species. These features are particularly important taking into account recent policies for mangrove bioreme-diation, implying that oil degradation as well as plant maintenance and health are key targets. Fifty-seven morphotypes were isolated from the mangrove rhizospheres on Bushneil-Haas (BH) medium supplemented with oil as the sole carbon source and tested for plant growth promotion. Of this strains, 60% potentially fixed nitrogen, 16% showed antimicrobial activity, 84% produced siderophores, 51% had the capacity to solubilize phosphate, and 33% produced the indole acetic acid hormone. Using gas chromatography, we evaluated the oil-degrading potential of ten selected strains that had different morphologies and showed Plant Growth Promoting Rhizobacteria (PGPR) features. The ten tested strains showed a promising degradation profile for at least one compound present in the oil. Among degrader strains, 46% had promising PGPR potential, having at least three of the above capacities. These strains might be used as a consortium, allowing the concomitant degradation of oil and stimulation of mangrove plant survival and maintenance.

  10. [Carbon storage and carbon sink of mangrove wetland: research progress].

    PubMed

    Zhang, Li; Guo, Zhi-hua; Li, Zhi-yong

    2013-04-01

    Mangrove forest is a special wetland forest growing in the inter-tidal zone of tropical and subtropical regions, playing important roles in windbreak, promoting silt sedimentation, resisting extreme events such as cyclones and tsunamis, and protecting coastline, etc. The total area of global mangrove forests is about 152000 km2, only accounting for 0. 4% of all forest area. There are about 230 km2 mangrove forests in China. The mangrove forests in the tropics have an average carbon storage as high as 1023 Mg hm-2, and the global mangrove forests can sequestrate about 0. 18-0. 228 Pg C a-1. In addition to plant species composition, a variety of factors such as air temperature, seawater temperature and salinity, soil physical and chemical properties, atmospheric CO2 concentration, and human activities have significant effects on the carbon storage and sink ability of mangrove forests. Many approaches based onfield measurements, including allometric equations, remote sensing, and model simulation, are applied to quantify the carbon storage and sink ability of mangrove forest wetland. To study the carbon storage and sink ability of mangrove wetland can promote the further understanding of the carbon cycle of mangrove wetland and related controlling mechanisms, being of significance for the protection and rational utilization of mangrove wetland.

  11. Mangroves in the Gulf of California increase fishery yields.

    PubMed

    Aburto-Oropeza, Octavio; Ezcurra, Exequiel; Danemann, Gustavo; Valdez, Víctor; Murray, Jason; Sala, Enric

    2008-07-29

    Mangroves are disappearing rapidly worldwide despite their well documented biodiversity and the ecosystem services they provide. Failure to link ecological processes and their societal benefits has favored highly destructive aquaculture and tourism developments that threaten mangroves and result in costly "externalities." Specifically, the potentially irreparable damage to fisheries because of mangrove loss has been belittled and is greatly underestimated. Here, we show that, in the Gulf of California, fisheries landings are positively related to the local abundance of mangroves and, in particular, to the productive area in the mangrove-water fringe that is used as nursery and/or feeding grounds by many commercial species. Mangrove-related fish and crab species account for 32% of the small-scale fisheries landings in the region. The annual economic median value of these fisheries is US $37,500 per hectare of mangrove fringe, falling within the higher end of values previously calculated worldwide for all mangrove services together. The ten-year discounted value of one hectare of fringe is >300 times the official cost set by the Mexican government. The destruction of mangroves has a strong economic impact on local fishing communities and on food production in the region. Our valuation of the services provided by mangroves may prove useful in making appropriate decisions for a more efficient and sustainable use of wetlands.

  12. Mangroves Enhance Reef Fish Abundance at the Caribbean Regional Scale.

    PubMed

    Serafy, Joseph E; Shideler, Geoffrey S; Araújo, Rafael J; Nagelkerken, Ivan

    2015-01-01

    Several studies conducted at the scale of islands, or small sections of continental coastlines, have suggested that mangrove habitats serve to enhance fish abundances on coral reefs, mainly by providing nursery grounds for several ontogenetically-migrating species. However, evidence of such enhancement at a regional scale has not been reported, and recently, some researchers have questioned the mangrove-reef subsidy effect. In the present study, using two different regression approaches, we pursued two questions related to mangrove-reef connectivity at the Caribbean regional scale: (1) Are reef fish abundances limited by mangrove forest area?; and (2) Are mean reef fish abundances proportional to mangrove forest area after taking human population density and latitude into account? Specifically, we tested for Caribbean-wide mangrove forest area effects on the abundances of 12 reef fishes that have been previously characterized as "mangrove-dependent". Analyzed were data from an ongoing, long-term (20-year) citizen-scientist fish monitoring program; coastal human population censuses; and several wetland forest information sources. Quantile regression results supported the notion that mangrove forest area limits the abundance of eight of the 12 fishes examined. Linear mixed-effects regression results, which considered potential human (fishing and habitat degradation) and latitudinal influences, suggested that average reef fish densities of at least six of the 12 focal fishes were directly proportional to mangrove forest area. Recent work questioning the mangrove-reef fish subsidy effect likely reflects a failure to: (1) focus analyses on species that use mangroves as nurseries, (2) consider more than the mean fish abundance response to mangrove forest extent; and/or (3) quantitatively account for potentially confounding human impacts, such as fishing pressure and habitat degradation. Our study is the first to demonstrate at a large regional scale (i.e., the Wider

  13. Mangroves Enhance Reef Fish Abundance at the Caribbean Regional Scale

    PubMed Central

    Serafy, Joseph E.; Shideler, Geoffrey S.; Araújo, Rafael J.; Nagelkerken, Ivan

    2015-01-01

    Several studies conducted at the scale of islands, or small sections of continental coastlines, have suggested that mangrove habitats serve to enhance fish abundances on coral reefs, mainly by providing nursery grounds for several ontogenetically-migrating species. However, evidence of such enhancement at a regional scale has not been reported, and recently, some researchers have questioned the mangrove-reef subsidy effect. In the present study, using two different regression approaches, we pursued two questions related to mangrove-reef connectivity at the Caribbean regional scale: (1) Are reef fish abundances limited by mangrove forest area?; and (2) Are mean reef fish abundances proportional to mangrove forest area after taking human population density and latitude into account? Specifically, we tested for Caribbean-wide mangrove forest area effects on the abundances of 12 reef fishes that have been previously characterized as “mangrove-dependent”. Analyzed were data from an ongoing, long-term (20-year) citizen-scientist fish monitoring program; coastal human population censuses; and several wetland forest information sources. Quantile regression results supported the notion that mangrove forest area limits the abundance of eight of the 12 fishes examined. Linear mixed-effects regression results, which considered potential human (fishing and habitat degradation) and latitudinal influences, suggested that average reef fish densities of at least six of the 12 focal fishes were directly proportional to mangrove forest area. Recent work questioning the mangrove-reef fish subsidy effect likely reflects a failure to: (1) focus analyses on species that use mangroves as nurseries, (2) consider more than the mean fish abundance response to mangrove forest extent; and/or (3) quantitatively account for potentially confounding human impacts, such as fishing pressure and habitat degradation. Our study is the first to demonstrate at a large regional scale (i.e., the Wider

  14. Lagoons and oxidation ponds. [Wastewater treatment

    SciTech Connect

    George, D.B.

    1982-06-01

    A review of the literature on waste stabilization pond systems is presented. Factors such as wastewater temperature, and levels of heavy metals that affect the stability of the lagoons and oxidation ponds, and methods to upgrade stabilization pond effluent to meet state and federal effluent requirements are discussed. Model simulations utilized to predict the treatment efficiency of various waste stabilization pond geometries, and inlet and outlet configurations are reviewed. (KRM)

  15. Hydrological dynamics of water sources in a Mediterranean lagoon

    NASA Astrophysics Data System (ADS)

    Stumpp, C.; Ekdal, A.; Gönenc, I. E.; Maloszewski, P.

    2014-12-01

    Lagoons are important ecosystems occupying large coastal areas worldwide. Lagoons contain various mixtures of marine and freshwater sources which are highly dynamic in time. However, it often remains a challenge to identify and quantify dynamic changes of water sources, particularly in heterogeneous lagoon systems like the Köycegiz-Dalyan lagoon (KDL), which is located at the south-west of Turkey on the Mediterranean Sea coast. The objective of this study was to quantify different contributions of potential water sources i.e. surface water, groundwater and seawater in the lagoon and how these water sources changed over time and space. In the wet- and dry-season stable isotopes of water, chloride concentration (Cl-) and salinity were measured in two depths in the lagoon and surrounding water bodies (sea, lake, groundwater). Different components of water sources were quantified with a three component endmember mixing analysis. Differences in Cl- and stable isotopes over time indicated the dynamic behaviour of the system. Generally, none of the groundwater samples was impacted by water of the Mediterranean Sea. During the wet season, most of the lagoon water (> 95%) was influenced by freshwater and vertically well mixed. During the dry season, high Cl- in the deeper sampling locations indicated a high contribution of marine water throughout the entire lagoon system due to saltwater intrusion. However, a distinct layering in the lagoon was obvious from low Cl- and depleted isotope contents close to the surface supporting freshwater inflow into the system even during the dry season. Besides temporal dynamics also spatial heterogeneities were identified. Changes in water sources were most evident in the main lagoon channel compared to more isolate lagoon lakes, which were influenced by marine water even in the wet season, and compared to side branches indicating slower turnover times. We found that environmental tracers helped to quantify highly dynamic and

  16. Computing the residence times in the Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Umgiesser, G.; Cucco, A.

    2003-04-01

    The Venice Lagoon is a shallow water body with a total area of about 500 km2. Three inlets govern the water exchanges between the Adriatic Sea and the Venice Lagoon. Water, entering and exiting through these channels during an entire tidal cycle, changes its biogeochemical and physical properties. The aim of this work is to investigate the Venice Lagoon circulation and to quantify the turn over time of the lagoon which mainly influences the water quality of the basin. The study has been carried out with a numerical model. The model computes the main hydrodynamic unknowns on a spatial domain that represents the Venice Lagoon and the Adriatic Sea with a finite element grid. The model considers as open boundary the line of Otranto channel in the southern Adriatic Sea and elsewhere as closed boundary the whole perimeter of the Adriatic Sea and Venice Lagoon. The model has been calibrated using the sea level data measured by more than twelve tide gauges located along the Adriatic Sea and inside the lagoon. The results obtained by the calibrated model have been validated with experimental data such as discharge data collected by botton mounted ADCP probes located at each inlet. The simulations take into account the tidal forcing and the different wind regimes. The instantaneous circulation and the residual current fields have been analyzed and the impact of the most important wind regimes on the circulation has been studied. The turn over time of the lagoon has been computed under different forcing conditions. A passive tracer only subjected to transport mechanism, has been released inside the lagoon. Resolving the time decaying of the tracer concentration for the whole area, the model computes the spatial distribution of the residence time in the basin. The results show that the re-import of water that previously exited the lagoon through the three inlets, plays an important role on the estimation of the turn over time of the lagoon thus influencing the water quality of

  17. CO2 Efflux from Cleared Mangrove Peat

    PubMed Central

    Lovelock, Catherine E.; Ruess, Roger W.; Feller, Ilka C.

    2011-01-01

    Background CO2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils. Methodology/Principal Findings We measured CO2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance of soils after clearing may have on CO2 efflux. CO2 efflux from soils declines from time of clearing from ∼10 600 tonnes km−2 year−1 in the first year to 3000 tonnes km2 year−1 after 20 years since clearing. Disturbing peat leads to short term increases in CO2 efflux (27 umol m−2 s−1), but this had returned to baseline levels within 2 days. Conclusions/Significance Deforesting mangroves that grow on peat soils results in CO2 emissions that are comparable to rates estimated for peat collapse in other tropical ecosystems. Preventing deforestation presents an opportunity for countries to benefit from carbon payments for preservation of threatened carbon stocks. PMID:21738628

  18. Downed Wood in micronesian mangrove Forests

    Treesearch

    James A. Allen; Katherine C. Ewel; Bobby D. Keeland; Tara Tara; Thomas J. Smith

    2000-01-01

    Dead, downed wood is an important component of upland forest and aquatic ecosystems, but its role in wetland ecosystems, including mangroves, is poorly understood. We measured downed wood in ten sites on the western Pacific islands of Kosrae, Pohnpei, and Yap, all located within the Federated States of Micronesia. Our goals were to examine patterns of variability in...

  19. Seasonal evapotranspiration patterns in mangrove forests

    NASA Astrophysics Data System (ADS)

    Barr, Jordan G.; DeLonge, Marcia S.; Fuentes, Jose D.

    2014-04-01

    Diurnal and seasonal controls on water vapor fluxes were investigated in a subtropical mangrove forest in Everglades National Park, Florida. Energy partitioning between sensible and latent heat fluxes was highly variable during the 2004-2005 study period. During the dry season, the mangrove forest behaved akin to a semiarid ecosystem as most of the available energy was partitioned into sensible heat, which gave Bowen ratio values exceeding 1.0 and minimum latent heat fluxes of 5 MJ d-1. In contrast, during the wet season the mangrove forest acted as a well-watered, broadleaved deciduous forest, with Bowen ratio values of 0.25 and latent heat fluxes reaching 18 MJ d-1. During the dry season, high salinity levels (> 30 parts per thousand, ppt) caused evapotranspiration to decline and correspondingly resulted in reduced canopy conductance. From multiple linear regression, daily average canopy conductance to water vapor declined with increasing salinity, vapor pressure deficit, and daily sums of solar irradiance but increased with air temperature and friction velocity. Using these relationships, appropriately modified Penman-Monteith and Priestley-Taylor models reliably reproduced seasonal trends in daily evapotranspiration. Such numerical models, using site-specific parameters, are crucial for constructing seasonal water budgets, constraining hydrological models, and driving regional climate models over mangrove forests.

  20. Investigating Extreme Lifestyles through Mangrove Transcriptomics

    ERIC Educational Resources Information Center

    Dassanayake, Maheshi

    2009-01-01

    Mangroves represent phylogenetically diverse taxa in tropical coastal terrestrial habitats. They are extremophiles, evolutionarily adapted to tolerate flooding, anoxia, high temperatures, wind, and high and extremely variable salt conditions in typically resource-poor environments. The genetic basis for these adaptations is, however, virtually…

  1. Investigating Extreme Lifestyles through Mangrove Transcriptomics

    ERIC Educational Resources Information Center

    Dassanayake, Maheshi

    2009-01-01

    Mangroves represent phylogenetically diverse taxa in tropical coastal terrestrial habitats. They are extremophiles, evolutionarily adapted to tolerate flooding, anoxia, high temperatures, wind, and high and extremely variable salt conditions in typically resource-poor environments. The genetic basis for these adaptations is, however, virtually…

  2. Mangrove Colonization: Mangrove Progression Over the Growing Pak Phanang (SE Thailand) Mud Flat

    NASA Astrophysics Data System (ADS)

    Panapitukkul, N.; Duarte, C. M.; Thampanya, U.; Kheowvongsri, P.; Srichai, N.; Geertz-Hansen, O.; Terrados, J.; Boromthanarath, S.

    1998-07-01

    A combination of remote sensing techniques and in situmeasurements along a chronosequence was used to elucidate the rate of progression of the mangrove forest in the Pak Phanang Bay (SE Thailand), a large bay with an extended and rapidly accreting mud flat. The examination of black and white aerial photographs of the forest in 1966, 1974, 1989 and 1995, and satellite images in 1985, 1990 and 1994 revealed that the mangrove forest located in the eastern bank of the bay was progressing over the mud flat. The rate of progression was estimated, from examination of changes in the position of the forest edge with time in the series of images, to average 38·6 m year -1over the 28-year interval encompassed by the images. Mangrove progression rates were fastest between 1966 and 1974 and slowest between 1974 and 1985, remaining uniform at about 30 m year -1thereafter. The in situexamination of vegetation along transects in the area of fastest mangrove progression showed an average progression rate of 53·12±5·86 m year -1, quite similar to the estimate (48·4 m year -1) derived from remote sensing techniques for the area where the transects were surveyed. Avicennia albawas found to dominate the vegetation at the progressing edge of the mangrove, followed by Sonneratia caseolaris, with Rhizophora apiculatabeing present only occasionally. The fast colonization of A. albaover the mud flat was supported by a large export flux of mangrove propagules from the channels draining the mangrove forest, which averaged 3715±920 and 1900±808 fruits day -1in each of the channels examined. Extrapolation of the long-term mean mangrove progression rate observed along the eastern bank of the Pak Phanang Bay suggested that this mangrove forest will increase by 33 ha year -1. These results provide evidence that natural mangrove colonization can be a rapid process if sufficient propagules of the pioneer species ( A. albaand S. caseolaris) are available, and point, therefore, to alternative

  3. Circulation patterns in a channel reef-lagoon system, Ouano lagoon, New Caledonia

    NASA Astrophysics Data System (ADS)

    Sous, Damien; Chevalier, Cristele; Devenon, Jean-Luc; Blanchot, Jean; Pagano, Marc

    2017-09-01

    This paper reports on two three-months field experiments carried out in the Ouano lagoon, New Caledonia. This channel-type lagoon, exposed to meso-tides, south pacific swells and trade winds, has been monitored thanks to a network of currents profilers to understand the dynamics of the lagoon waters. Four typical circulation patterns have been identified, covering all together more than 90% of the survey period. These patterns are mainly driven by the waves and wind features. In particular, obliquely incident waves or strong winds blowing over a sufficient period are able to reverse the typical circulation pattern. The analysis of the vertical structure of the currents through passages shows the regular presence of a nearly linear vertical shear within the water column.

  4. Sludge storage lagoon biogas recovery and use. Volume 2

    SciTech Connect

    Muller, D.; Norville, C.

    1991-07-01

    The City of Memphis has two wastewater treatment plants. The SWTP employs two large anaerobic digestion sludge lagoons as part of the overall sludge treatment system. Although these lagoons are effective in concentrating and digesting sludge, they can generate offensive odors. The SWTP uses aerobic digesters to partially stabilize the sludge and help reduce objectionable odors before it enters the lagoons. The anaerobic digestion of sludge in the lagoons results in the dispersion of a large quantity of biogas into the atmosphere. The City realized that if the lagoons could be covered, the odor problem could be resolved, and at the same, time, biogas could be recovered and utilized as a source of energy. In 1987, the City commissioned ADI International to conduct a feasibility study to evaluate alternative methods of covering the lagoons and recovering and utilizing the biogas. The study recommended that the project be developed in two phases: (1) recovery of the biogas and (2) utilization of the biogas. Phase 1 consists of covering the two lagoons with an insulated membrane to control odor and temperature and collect the biogas. Phase 1 was found to be economically feasible and offered a unique opportunity for the City to save substantial operating costs at the treatment facility. The Memphis biogas recovery project is the only application in the world where a membrane cover has been used on a municipal wastewater sludge lagoon. It is also the largest lagoon cover system in the world.

  5. Impacts of exotic mangrove forests and mangrove deforestation on carbon remineralization and ecosystem functioning in marine sediments

    USGS Publications Warehouse

    Sweetman, A.K.; Middelburg, J.J.; Berle, A.M.; Bernardino, A.F.; Schander, C.; Demopoulos, A.W.J.; Smith, C.R.

    2010-01-01

    To evaluate how mangrove invasion and removal can modify benthic carbon cycling processes and ecosystem functioning, we used stable-isotopically labelled algae as a deliberate tracer to quantify benthic respiration and C-flow through macrofauna and bacteria in sediments collected from (1) an invasive mangrove forest, (2) deforested mangrove sites 2 and 6 years after removal of above-sediment mangrove biomass, and (3) two mangrove-free, control sites in the Hawaiian coastal zone. Sediment oxygen consumption (SOC) rates were significantly greater in the mangrove and mangrove removal site experiments than in controls and were significantly correlated with total benthic (macrofauna and bacteria) biomass and sedimentary mangrove biomass (SMB). Bacteria dominated short-term C-processing of added microalgal-C and benthic biomass in sediments from the invasive mangrove forest habitat. In contrast, macrofauna were the most important agents in the short-term processing of microalgal-C in sediments from the mangrove removal and control sites. Mean faunal abundance and short term C-uptake rates in sediments from both removal sites were significantly higher than in control cores, which collectively suggest that community structure and short-term C-cycling dynamics in habitats where mangroves have been cleared can remain fundamentally different from un-invaded mudflat sediments for at least 6-yrs following above-sediment mangrove removal. In summary, invasion by mangroves can lead to large shifts in benthic ecosystem function, with sediment metabolism, benthic community structure and short-term C-remineralization dynamics being affected for years following invader removal. ?? 2010 Author(s).

  6. Vertical accretion and shallow subsidence in a mangrove forest of southwestern Florida, U.S.A

    USGS Publications Warehouse

    Cahoon, D.R.; Lynch, J.C.

    1997-01-01

    Simultaneous measurements of vertical accretion from artificial soil marker horizons and soil elevation change from sedimentation-erosion table (SET) plots were used to evaluate the processes related to soil building in range, basin, and overwash mangrove forests located in a low-energy lagoon which recieves minor inputs of terregenous sediments. Vertical accretion measures reflect the contribution of surficial sedimentation (sediment deposition and surface root growth). Measures of elevation change reflect not only the contributions of vertical accretion but also those of subsurface processes such as compaction, decomposition and shrink-swell. The two measures were used to calculate amounts of shallow subsidence (accretion minus elevation change) in each mangrove forest. The three forest types represent different accretionary envrionments. The basin forest was located behind a natural berm. Hydroperiod here was controlled primarily by rainfall rather than tidal exchange, although the basin flooded during extreme tidal events. Soil accretion here occurred primarily by autochthonous organic matter inputs, and elevation was controlled by accretion and shrink-swell of the substrate apparently related to cycles of flooding-drying and/or root growth-decomposition. This hydrologically-restricted forest did not experience an accretion or elevation deficit relative to sea-level rise. The tidally dominated fringe and overwash island forests accreted through mineral sediment inputs bound in place by plant roots. Filamentous turf algae played an important role in stabilizing loose muds in the fringe forest where erosion was prevalent. Elevation in these high-energy environments was controlled not only by accretion but also by erosion and/or shallow subsidence. The rate of shallow subsidence was consistently 3-4 mm y-1 in the fringe and overwash island forests but was negligible in the basin forest. Hence, the vertical development of mangrove soils was influenced by both

  7. Phylogeny of culturable cyanobacteria from Brazilian mangroves.

    PubMed

    Silva, Caroline Souza Pamplona; Genuário, Diego Bonaldo; Vaz, Marcelo Gomes Marçal Vieira; Fiore, Marli Fátima

    2014-03-01

    The cyanobacterial community from Brazilian mangrove ecosystems was examined using a culture-dependent method. Fifty cyanobacterial strains were isolated from soil, water and periphytic samples collected from Cardoso Island and Bertioga mangroves using specific cyanobacterial culture media. Unicellular, homocytous and heterocytous morphotypes were recovered, representing five orders, seven families and eight genera (Synechococcus, Cyanobium, Cyanobacterium, Chlorogloea, Leptolyngbya, Phormidium, Nostoc and Microchaete). All of these novel mangrove strains had their 16S rRNA gene sequenced and BLAST analysis revealed sequence identities ranging from 92.5 to 99.7% when they were compared with other strains available in GenBank. The results showed a high variability of the 16S rRNA gene sequences among the genotypes that was not associated with the morphologies observed. Phylogenetic analyses showed several branches formed exclusively by some of these novel 16S rRNA gene sequences. BLAST and phylogeny analyses allowed for the identification of Nodosilinea and Oxynema strains, genera already known to exhibit poor morphological diacritic traits. In addition, several Nostoc and Leptolyngbya morphotypes of the mangrove strains may represent new generic entities, as they were distantly affiliated with true genera clades. The presence of non-ribosomal peptide synthetase, polyketide synthase, microcystin and saxitoxin genes were detected in 20.5%, 100%, 37.5% and 33.3%, respectively, of the 44 tested isolates. A total of 134 organic extracts obtained from 44 strains were tested against microorganisms, and 26% of the extracts showed some antimicrobial activity. This is the first polyphasic study of cultured cyanobacteria from Brazilian mangrove ecosystems using morphological, genetic and biological approaches.

  8. Global trends and vulnerabilities of mangrove forests

    NASA Astrophysics Data System (ADS)

    Simard, M.; Fatoyinbo, T. E.; Rivera-Monroy, V. H.; Castaneda, E.; Roy Chowdhury, R.

    2015-12-01

    Mangrove forests are located along Earth's coastlines and estuaries within tropical and subtropical latitudes. They provide numerous services functioning as an extraordinary carbon sequestration system and serving as habitat and nursery for fish, crustaceans and amphibians. To coastal populations, they provide livelihood, food, lumber and act as an effective protection against tsunamis, storm surges and hurricanes. Their vulnerability to sea level rise is strongly related to their extraordinary ability to accumulate soils, which is in part related to their productivity and therefore canopy structure. As a first step to understand their vulnerability, we seek to understand mangrove dependencies on environmental and geophysical setting. To achieve this, we mapped mangrove canopy height and above ground biomass (AGB) at the Global scale. To identify mangrove forests, existing maps derived from a collection of Landsat data around the 2000 era were used. Using the Shuttle Radar Topography Mission elevation data collected in February of 2000, we produced a Global map of mangrove canopy height. The estimated heights were validated with the ICESat/Geoscience Altimeter System (GLAS) and in situ field data. Most importantly, field data were also used to derive relationships between canopy height and AGB. While the geographical coverage of in situ data is limited, ICESat/GLAS data provided extensive geographical coverage with independent estimates of maximum canopy height. These estimates were used to calibrate SRTM-estimates of height at the Global scale. We found the difference between GLAS RH100 and SRTM resulted from several sources of uncertainty that are difficult to isolate. These include natural variations of canopy structure with time, system errors from GLAS and SRTM, geo-location errors and discrepancies in spatial resolution. The Global canopy height map was trnasormed into AGB using the field-derived allometry. Depending on the scale of analysis and geographical

  9. Patterns of seasonal variation in lagoonal macrozoobenthic assemblages (Mellah lagoon, Algeria).

    PubMed

    Magni, Paolo; Draredja, Brahim; Melouah, Khalil; Como, Serena

    2015-08-01

    In coastal lagoons, many studies indicated that macrozoobenthic assemblages undergo marked temporal fluctuations as related to the strong environmental variability of these systems. However, most of these studies have not assessed the seasonal patterns of these fluctuations and none of them has investigated the consistency of this variation in different areas within the same lagoon system. In this study, we assessed patterns of variation at multiple temporal (date, season and year) scales in two different areas in the coastal lagoon of Mellah (northeast Algeria). These areas (hereafter Shore and Center) are representative of two different environments typically found in coastal lagoons. The Shore (water depth of about 1.5-2 m) is characterized by relatively higher hydrodynamics, sand to silty-sand sediments and the presence of vegetation (Ruppia maritima), the Center (water depth of about 3-3.5 m) is characterized by mud to sandy-mud, organic-enriched sediments due to fine particle accumulation. Results showed two distinct patterns of seasonal variation in Shore and Center assemblages for two consecutive years. In Shore, species richness (S), total abundance (N) and the abundance of several dominant taxa were highest in summer and/or autumn. This pattern can be related to the local environmental conditions maintaining relatively well oxidized conditions, while increasing food availability, and favoring the recruitment of species and individuals in summer/autumn. On the contrary in Center, S was lowest in summer and autumn, and N and the abundance of fewer dominant taxa were lowest in summer. In Center, the bivalve Loripes lucinalis showed a 10-fold increase from summer to autumn in both years, likely related to the lagoon's hydrodynamics favoring larval transport and settlement in the central sector of the lagoon. Overall, the seasonal variation found in Center followed a regression/recovery pattern typical of opportunistic assemblages occurring in confined

  10. Assessing N2 fixation in estuarine mangrove soils

    NASA Astrophysics Data System (ADS)

    Shiau, Yo-Jin; Lin, Ming-Fen; Tan, Chen-Chung; Tian, Guanglong; Chiu, Chih-Yu

    2017-04-01

    Nitrogen (N) limited mangrove forest may have a high potential for microbial N2 fixation. Previous research has focused on soil nitrogenase activity in pristine mangrove forests with little anthropogenic impact. This research was designed to evaluate the magnitude of nitrogenase activity of mangrove soils in a high anthropogenic N-loading environment and the way in which soil N2 fixation in mangrove forest may be related to organic carbon and salinity. The test involved an acetylene reduction method under controlled laboratory conditions. The mangrove forests with high anthropogenic N loading may have high nitrogenase activity in the soils. The diazotrophs in these mangrove soils were mostly heterotrophs and the sulfate-reducing bacteria were the major N2-fixing bacteria. The nitrogenase activity was little affected by the soil salinity, which suggests that these groups of N2 fixation bacteria adapted well to saline conditions in the estuary.

  11. The current status of world protection for mangrove forest

    NASA Astrophysics Data System (ADS)

    Zhengyun, Zhang; Zhixian, Su; Qiaoying, Zhang; Aiying, Shen

    2003-09-01

    Mangrove forests occur extensively in the tropic areas rich in wildlife and other nonforestry resources and provide a wide array of raw materials for livelihood and production processes and have been a major source of income generation and subsistence for the local people. Exploitation of timber, fuel wood, poles, industrial raw material, and many other non-wood produets from the mangrove forests give rise to large scale economic activity and income generation. At present, mangrove forests are facing great peril. Reckless exploitation and swampland reclamation result in their gradual degradation. This article deals with the world’s mangrove forest resources and their benefit to people; describes the current status, points out the main causes of the destruction of these forests, presents proposals for protecting mangrove forests, and discusses international cooperation in protecting the world’s mangrove forests.

  12. Major Sources of Organic Matter in a Complex Coral Reef Lagoon: Identification from Isotopic Signatures (δ13C and δ15N).

    PubMed

    Briand, Marine J; Bonnet, Xavier; Goiran, Claire; Guillou, Gaël; Letourneur, Yves

    2015-01-01

    A wide investigation was conducted into the main organic matter (OM) sources supporting coral reef trophic networks in the lagoon of New Caledonia. Sampling included different reef locations (fringing, intermediate and barrier reef), different associated ecosystems (mangroves and seagrass beds) and rivers. In total, 30 taxa of macrophytes, plus pools of particulate and sedimentary OM (POM and SOM) were sampled. Isotopic signatures (C and N) of each OM sources was characterized and the composition of OM pools assessed. In addition, spatial and seasonal variations of reef OM sources were examined. Mangroves isotopic signatures were the most C-depleted (-30.17 ± 0.41 ‰) and seagrass signatures were the most C-enriched (-4.36 ± 0.72 ‰). Trichodesmium spp. had the most N-depleted signatures (-0.14 ± 0.03 ‰) whereas mangroves had the most N-enriched signatures (6.47 ± 0.41 ‰). The composition of POM and SOM varied along a coast-to-barrier reef gradient. River POM and marine POM contributed equally to coastal POM, whereas marine POM represented 90% of the POM on barrier reefs, compared to 10% river POM. The relative importance of river POM, marine POM and mangroves to the SOM pool decreased from fringing to barrier reefs. Conversely, the relative importance of seagrass, Trichodesmium spp. and macroalgae increased along this gradient. Overall, spatial fluctuations in POM and SOM were much greater than in primary producers. Seasonal fluctuations were low for all OM sources. Our results demonstrated that a large variety of OM sources sustain coral reefs, varying in their origin, composition and role and suggest that δ13C was a more useful fingerprint than δ15N in this endeavour. This study also suggested substantial OM exchanges and trophic connections between coral reefs and surrounding ecosystems. Finally, the importance of accounting for environmental characteristics at small temporal and spatial scales before drawing general patterns is highlighted.

  13. Major Sources of Organic Matter in a Complex Coral Reef Lagoon: Identification from Isotopic Signatures (δ13C and δ15N)

    PubMed Central

    Briand, Marine J.; Bonnet, Xavier; Goiran, Claire; Guillou, Gaël; Letourneur, Yves

    2015-01-01

    A wide investigation was conducted into the main organic matter (OM) sources supporting coral reef trophic networks in the lagoon of New Caledonia. Sampling included different reef locations (fringing, intermediate and barrier reef), different associated ecosystems (mangroves and seagrass beds) and rivers. In total, 30 taxa of macrophytes, plus pools of particulate and sedimentary OM (POM and SOM) were sampled. Isotopic signatures (C and N) of each OM sources was characterized and the composition of OM pools assessed. In addition, spatial and seasonal variations of reef OM sources were examined. Mangroves isotopic signatures were the most C-depleted (-30.17 ± 0.41 ‰) and seagrass signatures were the most C-enriched (-4.36 ± 0.72 ‰). Trichodesmium spp. had the most N-depleted signatures (-0.14 ± 0.03 ‰) whereas mangroves had the most N-enriched signatures (6.47 ± 0.41 ‰). The composition of POM and SOM varied along a coast-to-barrier reef gradient. River POM and marine POM contributed equally to coastal POM, whereas marine POM represented 90% of the POM on barrier reefs, compared to 10% river POM. The relative importance of river POM, marine POM and mangroves to the SOM pool decreased from fringing to barrier reefs. Conversely, the relative importance of seagrass, Trichodesmium spp. and macroalgae increased along this gradient. Overall, spatial fluctuations in POM and SOM were much greater than in primary producers. Seasonal fluctuations were low for all OM sources. Our results demonstrated that a large variety of OM sources sustain coral reefs, varying in their origin, composition and role and suggest that δ13C was a more useful fingerprint than δ15N in this endeavour. This study also suggested substantial OM exchanges and trophic connections between coral reefs and surrounding ecosystems. Finally, the importance of accounting for environmental characteristics at small temporal and spatial scales before drawing general patterns is highlighted. PMID

  14. Sedimentology of onshore tsunami deposits of the Indian Ocean tsunami, 2004 in the mangrove forest of the Curieuse Marine National Park, Seychelles

    NASA Astrophysics Data System (ADS)

    Nentwig, V.; Bahlburg, H.; Monthy, D.

    2012-12-01

    . On small ledges of a granitic body at 120 m from the shore fragmented and complete shells were deposited at different elevations of up to 4 m. This implies a run up height of at least 4 m above sea level at this distance from the shore. Our study presents the mapping of the tsunamigenic sand lobes, their grain size distribution and petrographic variations of their components compared to the mangrove soil. The difference in the grain size and amount of organic material of the mangrove soil compared to the sand lobes indicate that the coarser material was entrained from outside of the mangrove forest by the tsunami. The similarity of the grain size distributions of the sediment of the sand lobes and of a reference beach/intertidal sample suggests the lagoon between the mangrove forest and the causeway as the probable sediment source area. The fact that the mangrove forest is surrounded by granitic hills and the appearance of the carbonate sandstone debris mostly on the surface of the sand sheets supports this assumption.

  15. Lagoon Seepage Testing Report for Central Facilities Area (CFA) Sewage Lagoons at Idaho National Laboratory, Butte County, Idaho

    SciTech Connect

    Morrison, Bridger

    2014-09-01

    J-U-B ENGINEERS, Inc. (J-U-B) performed seepage tests on the CFA Wastewater Lagoons 1, 2, and 3 between August 26th and September 22nd, 2014. The lagoons were tested to satisfy the Idaho Department of Environmental Quality (DEQ) Rules (IDAPA 58.01.16) that require all lagoons be tested at a frequency of every 10 years and the Compliance Activity CA-141-03 in the DEQ Wastewater Reuse Permit for the CFA Sewage Treatment Plant (LA-000141-03). The lagoons were tested to determine if the average seepage rates are less than 0.25 in/day, the maximum seepage rate allowed for lagoons built prior to April 15, 2007. The average seepage rates were estimated for each lagoon and are given in Table-ES1. The average seepage rates for Lagoons 1 and 2 are less than the allowable seepage rate of 0.25 in/day. Lagoon 1 and 2 passed the seepage test and will not have to be tested again until the year 20241. However, the average seepage rate for Lagoon 3 appears to exceed the allowable seepage rate of 0.25 in/day which means the potential source for the excessive leakage should be investigated further.

  16. Ecophysiological differences between three mangrove seedlings (Kandelia obovata, Aegiceras corniculatum, and Avicennia marina) exposed to chilling stress.

    PubMed

    Peng, Ya-Lan; Wang, You-Shao; Fei, Jiao; Sun, Cui-Ci; Cheng, Hao

    2015-10-01

    Although the cold-resistant ability of mangroves varies greatly with species, the physiological mechanism remains unclear. The chilling stress effects on morphological changes, photosynthetic pigments, reactive oxygen species (ROS), malondialdehyde (MDA) and several antioxidants, were studied in leaves of three mangrove seedlings (Kandelia obovata, Aegiceras corniculatum and Avicennia marina). Results showed that both K. obovata and A. corniculatum exhibited lighter chilling damage, lower chilling injury rates and higher survival rates compared to A. marina. Reductions of chlorophylls (Chls) were observed in all the three mangroves, and the highest was detected in A. marina. Significant increases in content of ROS (hydrogen peroxide, H2O2; hydroxyl radicals, OH⋅) and MDA were observed in both A. marina and A. corniculatum, whereas chilling stressed K. obovata showed a decrease in H2O2 content, constant OH⋅ level and instantaneous increase of MDA. The contents of proline and water-soluble protein exhibited similar stress-time dependent increases in all mangroves, while A. corniculatum showed the highest increase of proline and relatively higher increase of water-soluble protein. The catalase activities significantly decreased with stress time in all mangroves, while K. obovata showed the least reduction. An increase in ascorbic acid (AsA) content and activities of superoxide dismutase, peroxidase (POD), and ascorbate peroxidase (APX) were also detected in all the three mangroves, while K. obovata showed the highest increases. These results indicate that chilling-tolerance of mangroves is associated with the efficiency of antioxidants, as confirmed by principal component analysis. The AsA, APX and POD in K. obovata may play more important role in control of oxidative stresses than those in the other two species. Furthermore, the higher cold-resistance of A. corniculatum compared to A. marina may be partly associated with its higher proline accumulation. The

  17. Ecology of mangroves in the Jewfish Chain, Exuma, Bahamas

    USGS Publications Warehouse

    Wilcox, L. V.; Yocom, Thomas G.; Forbes, A. M.

    1976-01-01

    The structure and function of mangrove communities in the Jewfish Chain, Exumas, Bahamas, were investigated for 3-1/2 years. Mangrove vegetation in the Jewfish Chain is similar to that in all the Caribbean-Florida area; Rhizophora mangle L. dominates and is interspersed with Avicennia germinans (L.) Lamk. and Laguncularia racemosa (L.) Gaertn. There is no apparent zonation of these three species. The mangrove communities in the Jewfish Chain occur only where they are protected from prevailing winds, storms, and tides, although all are periodically devastated by hurricanes. We found little or no evidence of coast building within these protected locations. The importance of the mangroves appears to be in providing protection and food for other flora and fauna within this unique ecosystem. Twenty-four species of algae were found in the mangroves, 9 of which had not previously been reported from the Bahamas. Distribution of these algae appears to be correlated to incident solar radiation, desiccation, and tide level. A total of 56 species of fish were found in the mangroves, 2 of which were not previously known from the Bahamas. Many fish taken were juveniles, suggesting that mangroves are a nursery ground for numerous species. Nine species of molluscs were found. Each species had a distinct distribution pattern relative to distance from the seaward edge of the mangroves, as well as a distinct vertical distribution pattern. Seventeen species of decapod crustaceans were recorded. Though several species of birds were noted in the mangroves, three species were most abundant: the white-crowned pigeon (Columba leucocephala) uses the mangrove for nesting but feeds in nearby shrub-thorn communities; the gray kingbird (Tyrannus dominicensis) and green heron (Butorides virescens) nest and feed in the mangroves. Our data do not completely describe a stereotyped mangrove community in the Bahamas, but they do give an indication of community structure and suggest several

  18. Project Of Investigation About Growth Of Afforestation Mangrove In Thailand

    NASA Astrophysics Data System (ADS)

    Ibuki, R.

    2007-12-01

    At the mangrove which was played back artificially by intended afforestation it designates that related characteristic of growth circumstance and growth environment of the mangrove plant which is grown is evaluated as purpose of this study. Revival of the mangrove in Thailand with afforestation makes the ecosystem revive which consists simultaneously with the mangrove, makes the fishing industry profit at neighborhood possible, makes the life of the people of the locale rich. In addition, the mangrove carries out the role of the anti wave forest, the case of the Sumatra open sea earthquake makes the damage decrease by the tidal wave. The people of the locale re-have recognized concerning the inevitability of the mangrove. Difference has occurred in the amount of mangrove growth depending upon the growth place, the fact that these causes are investigated is something which urges the growth of the efficient mangrove at the time of future afforestation being active. In addition, also comparison of growth circumstance of the mangrove due to natural growth and the mangrove due to afforestation becomes the important research resource. Concretely, it measures growth circumstance (height of tree and diameter etc.) and also, growth environment (the amount of solar radiation, salinity density in substrate and tidal change etc.) and evaluate both correlations. As for evaluation of growth environment of the afforestation mangrove we should evaluate with central value. Because of that, there is a necessity which executes amount of growth measurement with statistical technique. Therefore, with the amount of growth measurement with lumbering, it is unsuitable to the measurement on this study. Regarding this subject of study, growth investigation of the group of trees is executed making use of non destructive physical amount (height of tree and diameter etc.) measurement. It measures at several dozen threes in plural afforestation area, evaluates the growth environment of each

  19. Ecological role and services of tropical mangrove ecosystems: a reassessment

    USGS Publications Warehouse

    Lee, Shing Yip; Primavera, Jurgene H.; Dahdouh-Guebas, Farid; McKee, Karen; Bosire, Jared O.; Cannicci, Stefano; Diele, Karen; Fromard, Francois; Koedam, Nico; Marchand, Cyril; Mendelssohn, Irving; Mukherjee, Nibedita; Record, Sydne

    2014-01-01

    Knowledge of thresholds, spatio-temporal scaling and variability due to geographic, biogeographic and socio-economic settings will improve the management of mangrove ecosystem services. Many drivers respond to global trends in climate change and local changes such as urbanization. While mangroves have traditionally been managed for subsistence, future governance models must involve partnerships between local custodians of mangroves and offsite beneficiaries of the services.

  20. Mangroves in the Gulf of California increase fishery yields

    PubMed Central

    Aburto-Oropeza, Octavio; Ezcurra, Exequiel; Danemann, Gustavo; Valdez, Víctor; Murray, Jason; Sala, Enric

    2008-01-01

    Mangroves are disappearing rapidly worldwide despite their well documented biodiversity and the ecosystem services they provide. Failure to link ecological processes and their societal benefits has favored highly destructive aquaculture and tourism developments that threaten mangroves and result in costly “externalities.” Specifically, the potentially irreparable damage to fisheries because of mangrove loss has been belittled and is greatly underestimated. Here, we show that, in the Gulf of California, fisheries landings are positively related to the local abundance of mangroves and, in particular, to the productive area in the mangrove–water fringe that is used as nursery and/or feeding grounds by many commercial species. Mangrove-related fish and crab species account for 32% of the small-scale fisheries landings in the region. The annual economic median value of these fisheries is US $37,500 per hectare of mangrove fringe, falling within the higher end of values previously calculated worldwide for all mangrove services together. The ten-year discounted value of one hectare of fringe is >300 times the official cost set by the Mexican government. The destruction of mangroves has a strong economic impact on local fishing communities and on food production in the region. Our valuation of the services provided by mangroves may prove useful in making appropriate decisions for a more efficient and sustainable use of wetlands. PMID:18645185

  1. The physiology of mangrove trees with changing climate

    USGS Publications Warehouse

    Lovelock, Catherine E.; Krauss, Ken W.; Osland, Michael J.; Reef, Ruth; Ball, Marilyn C.; Meinzer, Frederick C.; Niinemets, Ülo

    2016-01-01

    Mangrove forests grow on saline, periodically flooded soils of the tropical and subtropical coasts. The tree species that comprise the mangrove are halophytes that have suites of traits that confer differing levels of tolerance of salinity, aridity, inundation and extremes of temperature. Here we review how climate change and elevated levels of atmospheric CO2 will influence mangrove forests. Tolerance of salinity and inundation in mangroves is associated with the efficient use of water for photosynthetic carbon gain which unpins anticipated gains in productivity with increasing levels of CO2. We review evidence of increases in productivity with increasing CO2, finding that enhancements in growth appear to be similar to trees in non-mangrove habitats and that gains in productivity with elevated CO2 are likely due to changes in biomass allocation. High levels of trait plasticity are observed in some mangrove species, which potentially facilitates their responses to climate change. Trait plasticity is associated with broad tolerance of salinity, aridity, low temperatures and nutrient availability. Because low temperatures and aridity place strong limits on mangrove growth at the edge of their current distribution, increasing temperatures over time and changing rainfall patterns are likely to have an important influence on the distribution of mangroves. We provide a global analysis based on plant traits and IPCC scenarios of changing temperature and aridity that indicates substantial global potential for mangrove expansion.

  2. Microbial diversity in Brazilian mangrove sediments - a mini review.

    PubMed

    Ghizelini, Angela Michelato; Mendonça-Hagler, Leda Cristina Santana; Macrae, Andrew

    2012-10-01

    The importance and protection of mangrove ecosystems has been recognized in Brazilian Federal law since 1965. Being protected in law, however, has not always guaranteed their protection in practice. Mangroves are found in coastal and estuarine locations, which are prime real estate for the growth of cities, ports and other economic activities important for Brazilian development. In this mini-review we introduce what mangroves are and why they are so important. We give a brief overview of the microbial diversity found in mangrove sediments and then focus on diversity studies from Brazilian mangroves. We highlight the breadth and depth of knowledge about mangrove microbial communities gained from studying Brazilian mangroves. We report on the exciting findings of molecular microbial ecology methods that have been very successfully applied to study bacterial communities. We note that there have been fewer studies that focus on fungal communities and that fungal diversity studies deserve more attention. The review ends with a look at how a combination of new molecular biology methods and isolation studies are being developed to monitor and conserve mangrove ecosystems and their associated microbial communities. These recent studies are having a global impact and we hope they will help to protect and re-establish mangrove ecosystems.

  3. Mangrove expansion into salt marshes alters associated faunal communities

    NASA Astrophysics Data System (ADS)

    Smee, Delbert L.; Sanchez, James A.; Diskin, Meredith; Trettin, Carl

    2017-03-01

    Climate change is altering the distribution of foundation species, with potential effects on organisms that inhabit these environments and changes to valuable ecosystem functions. In the Gulf of Mexico, black mangroves (Avicennia germinans) are expanding northward into salt marshes dominated by Spartina alterniflora (hereafter Spartina). Salt marshes are essential habitats for many organisms, including ecologically and economically important species such as blue crabs (Callinectes sapidus) and Penaeid shrimp (e.g., Penaeus aztecus), which may be affected by vegetation changes. Black mangroves occupied higher tidal elevations than Spartina, and Spartina was present only at its lowest tidal elevations in sites when mangroves were established. We compared nekton and infaunal communities within monoculture stands of Spartina that were bordered by mangroves to nearby areas where mangroves had not yet become established. Nekton and infaunal communities were significantly different in Spartina stands bordered by mangroves, even though salinity and temperature were not different. Overall abundance and biomass of nekton and infauna was significantly higher in marshes without mangroves, although crabs and fish were more abundant in mangrove areas. Black mangrove expansion as well as other ongoing vegetation shifts will continue in a warming climate. Understanding how these changes affect associated species is necessary for management, mitigation, and conservation.

  4. [The Purruja mangrove, Golfito, Costa Rica: a management model].

    PubMed

    Silva, Ana Margarita; Carrillo, Norma Natalia

    2004-12-01

    The Purruja mangrove (Golfito, Costa Rica) has an estimated area of 70 ha. A socio-biological research was the ground to set initial goals to manage the resources and to identify the mangrove biological condition. Community participation and the local organization were key factors in developing an integrated model for the management of natural resources. Constant monitoring and institutional networks were the other two factors to manage the mangrove. The constant profesional support was a tool to facilitate the acomplishment of goals and to establish an institucional network to promote local group iniciatives for collaborative management of the Purruja mangrove.

  5. Paradigms of mangroves in treatment of anthropogenic wastewater pollution.

    PubMed

    Ouyang, Xiaoguang; Guo, Fen

    2016-02-15

    Mangroves have been increasingly recognized for treating wastewater from aquaculture, sewage and other sources with the overwhelming urbanization trend. This study clarified the three paradigms of mangroves in disposing wastewater contaminants: natural mangroves, constructed wetlands (including free water surface and subsurface flow) and mangrove-aquaculture coupling systems. Plant uptake is the common major mechanism for nutrient removal in all the paradigms as mangroves are generally nitrogen and phosphorus limited. Besides, sediments accrete and provide substrates for microbial activities, thereby removing organic matter and nutrients from wastewater in natural mangroves and constructed wetlands. Among the paradigms, the mangrove-aquaculture coupling system was determined to be the optimal alternative for aquaculture wastewater treatment by multi-criterion decision making. Sensitivity analysis shows variability of alternative ranking but underpins the coupling system as the most environment-friendly and cost-efficient option. Mangrove restoration is expected to be achievable if aquaculture ponds are planted with mangrove seedlings, creating the coupling system. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Microbial diversity in Brazilian mangrove sediments – a mini review

    PubMed Central

    Ghizelini, Angela Michelato; Mendonça-Hagler, Leda Cristina Santana; Macrae, Andrew

    2012-01-01

    The importance and protection of mangrove ecosystems has been recognized in Brazilian Federal law since 1965. Being protected in law, however, has not always guaranteed their protection in practice. Mangroves are found in coastal and estuarine locations, which are prime real estate for the growth of cities, ports and other economic activities important for Brazilian development. In this mini-review we introduce what mangroves are and why they are so important. We give a brief overview of the microbial diversity found in mangrove sediments and then focus on diversity studies from Brazilian mangroves. We highlight the breadth and depth of knowledge about mangrove microbial communities gained from studying Brazilian mangroves. We report on the exciting findings of molecular microbial ecology methods that have been very successfully applied to study bacterial communities. We note that there have been fewer studies that focus on fungal communities and that fungal diversity studies deserve more attention. The review ends with a look at how a combination of new molecular biology methods and isolation studies are being developed to monitor and conserve mangrove ecosystems and their associated microbial communities. These recent studies are having a global impact and we hope they will help to protect and re-establish mangrove ecosystems. PMID:24031949

  7. Hydrological classification of mangrove forests: a tool for successful mangrove rehabilitation

    NASA Astrophysics Data System (ADS)

    van Huijgevoort, Marjolein; van Loon, Anne; te Brake, Bram; Dijksma, Roel

    2015-04-01

    Mangrove forests are very valuable for coastal protection, ecosystem functioning and supporting livelihoods of coastal communities. Nevertheless, the size, number and ecological quality of mangrove forests are declining worldwide due to human influence like logging, aquaculture, and coastal development. To restore mangrove forests, rehabilitation projects are necessary. Unfortunately, many of these projects fail, because the hydrological conditions are not taken into account. This is understandable because hydrological conditions in mangrove forests are highly variable in time and space. To increase the success rate of rehabilitation projects a hydrological classification, which links hydrological site characteristics, such as inundation duration, to common mangrove species, could be a useful tool. This study investigates the potential of such a classification at a number of locations with natural and disturbed hydrological conditions. The hydrological classification has been developed from field data of two natural sites in Vietnam based on an existing classification (Watson, 1928). For all sites, data of water levels in the open water and at various locations across the mangrove forest were collected, and the vegetation composition at the measurement locations was determined during various field campaigns. From the water level data, the tidal regime, tidal frequency, and duration of inundation in minutes per day and minutes per inundation were derived. Testing has shown that, because of the irregular tidal regime and the effect of stagnant water due to (micro-)topography, tidal regime and frequency are not representative for the hydrological conditions determining mangrove species distribution. Duration of inundation in minutes per day and minutes per inundation are, however, both crucial factors for mangrove zonation and are therefore essential in a hydrological classification for mangroves. Six distinct classes were distinguished that are linked to the

  8. Determination of mangrove change in Matang Mangrove Forest using multi temporal satellite imageries

    NASA Astrophysics Data System (ADS)

    Ibrahim, N. A.; Mustapha, M. A.; Lihan, T.; Ghaffar, M. A.

    2013-11-01

    Mangrove protects shorelines from damaging storm and hurricane winds, waves, and floods. Mangroves also help prevent erosion by stabilizing sediments with their tangled root systems. They maintain water quality and clarity, filtering pollutants and trapping sediments originating from land. However, mangrove has been reported to be threatened by land conversion for other activities. In this study, land use and land cover changes in Matang Mangrove Forest during the past 18 years (1993 to 2011) were determined using multi-temporal satellite imageries by Landsat TM and RapidEye. In this study, classification of land use and land cover approach was performed using the maximum likelihood classifier (MCL) method along with vegetation index differencing (NDVI) technique. Data obtained was evaluated through Kappa coefficient calculation for accuracy and results revealed that the classification accuracy was 81.25% with Kappa Statistics of 0.78. The results indicated changes in mangrove forest area to water body with 2,490.6 ha, aquaculture with 890.7 ha, horticulture with 1,646.1 ha, palm oil areas with 1,959.2 ha, dry land forest with 2,906.7 ha and urban settlement area with 224.1 ha. Combinations of these approaches were useful for change detection and for indication of the nature of these changes.

  9. Characterisation and Comparison of Aliphatic Hydrocarbons Extracted from Different Mangrove Species in Cochin estuary (South West Coast of India)

    NASA Astrophysics Data System (ADS)

    Moolakkal Antony, R.

    2016-02-01

    The samples are collected from Malippuram (10.020 N, 76.210 E), Cochin estuary (South West Coast of India). The area contains various mangrove species, in which we have collected 4 common species (Acanthus Ilicifolis, Avicennia Marina, Avcennia Officianalis and Acrosticum Aurum) among the dominant species in the area. The leaves of these collected samples were freeze dried, grinded and extracted with solvents using standard protocols. The organic layer separated is used for analysing hydrocarbon (n-alkanes and n-alkenes) using Column Chromatography. Recent study (Gireeshkumar et al., 2015) revealed that, long-chain n-alkanes derived from higher plants predominated the inner part of the estuary, while short-chain n-alkanes derived from planktonic sources predominated the bar mouth region. Mangroves are one among the world's most productive ecosystem and form an important part of the coastal and estuarine environment. Living at the interface between land and sea, the mangrove plants have morphological and physiological adaptations to survive in harsh saline environment. Mangroves produce organic carbon well in excess of the ecosystem requirement and contribute significantly to global carbon cycle. They have enormous ecological value. This is the first report of n-alkanes and n-alkenes from these major species in the study area. The qualitative aspects of this study completed and the quantitative aspect is in progress. The stem and root of the collected samples are preserved for future extraction studies.

  10. Interspecific variation of the bacterial community structure in the phyllosphere of the three major plant components of mangrove forests

    PubMed Central

    Dias, Armando Cavalcante Franco; Taketani, Rodrigo Gouveia; Andreote, Fernando Dini; Luvizotto, Danice Mazzer; da Silva, João Luis; Nascimento, Rosely dos Santos; de Melo, Itamar Soares

    2012-01-01

    Mangrove forests encompass a group of trees species that inhabit the intertidal zones, where soil is characterized by the high salinity and low availability of oxygen. The phyllosphere of these trees represent the habitat provided on the aboveground parts of plants, supporting in a global scale, a large and complex microbial community. The structure of phyllosphere communities reflects immigration, survival and growth of microbial colonizers, which is influenced by numerous environmental factors in addition to leaf physical and chemical properties. Here, a combination of culture-base methods with PCR-DGGE was applied to test whether local or plant specific factors shape the bacterial community of the phyllosphere from three plant species (Avicenia shaueriana, Laguncularia racemosa and Rhizophora mangle), found in two mangroves. The number of bacteria in the phyllosphere of these plants varied between 3.62 x 104 in A. schaeriana and 6.26 x 103 in R. mangle. The results obtained by PCR-DGGE and isolation approaches were congruent and demonstrated that each plant species harbor specific bacterial communities in their leaves surfaces. Moreover, the ordination of environmental factors (mangrove and plant species), by redundancy analysis (RDA), also indicated that the selection exerted by plant species is higher than mangrove location on bacterial communities at phyllosphere. PMID:24031877

  11. Are coastal lagoons physically or biologically controlled ecosystems? Revisiting r vs. K strategies in coastal lagoons and estuaries

    NASA Astrophysics Data System (ADS)

    Pérez-Ruzafa, Angel; Marcos, Concepción; Pérez-Ruzafa, Isabel María; Pérez-Marcos, María

    2013-11-01

    Environmental stress influences biological assemblages, with species responding to stress by adopting particular life-history strategies (e.g., r vs. K). Coastal lagoons and estuaries are considered naturally stressed and physically controlled systems with frequent environmental disturbances and fluctuations. At the same time, their transitional nature (between terrestrial, freshwater and marine) makes them especially vulnerable to human impacts and land and freshwater inputs. As a result, it is hypothesised that residents of coastal lagoons would display characteristics of r-selected species. The r-strategy involves increased reproductive effort through early reproduction, small and numerous offspring with a large dispersive capability, short lifespan and small adult body size. Together, these traits provide a selective advantage in such unpredictable or short-lived environments. Alternatively, immigrants to coastal lagoons should mostly be K-strategists, with a competitive advantage over the r-strategists, at least on a temporary time scale. These hypotheses were explored using a dataset from 73 Atlanto-Mediterranean sites: 27 estuaries, 42 coastal lagoons and 4 from the sea, obtained from published sources. A detailed analysis of the distributions of the different resident fish species according to lagoon characteristics indicated that in lagoons with a higher marine influence the families Gobiidae, Blenniidae and Syngnathidae were common, while lagoons with freshwater influence are characterized by Cyprinidae and other freshwater species. In analyzing the biological strategies of lagoon species we found that fish assemblages inhabiting marine influenced lagoons were characterized by solitary, necto-benthonic sedentary species. These species are often hermaphroditic, with benthic broods and many exhibit brooding behaviour. This suggests that marine influenced lagoons are dominated by K-strategist species, while r-strategy species will be more common in

  12. Submarine groundwater discharge into typical tropical lagoons: A case study in eastern Hainan Island, China

    NASA Astrophysics Data System (ADS)

    Wang, Xilong; Du, Jinzhou

    2016-11-01

    Assessing submarine groundwater discharge (SGD) into lagoons and bays can be helpful to understand biogeochemical processes, especially nutrient dynamics. In the present paper, radium (Ra) isotopes were used to quantify SGD in two typical tropical lagoons (Laoye Lagoon (LY Lagoon) and Xiaohai Lagoon (XH Lagoon)) of eastern Hainan Island, China. The Ra mass balance model provided evidence that SGD plays an important role in the hydrology of the LY Lagoon and the XH Lagoon, delivering average SGD fluxes of 1.7 × 106 (94 L m-2 d-1) and 1.8 × 106 (41 L m-2 d-1) m3 d-1, respectively. Tidal pumping was one of the important driving forces for SGD fluxes in the LY and the XH Lagoons. Tidal-driven SGD into the tidal channels of both lagoons can account for approximately 10% of the total SGD flux into the lagoons. In addition, the dissolved inorganic nutrient budgets were reassessed in the LY Lagoon and the XH Lagoon, which showed that SGD was the major source of nutrients entering the LY Lagoon and that the LY Lagoon behaved as a source for dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) and as a sink for dissolved silicate (DSi). Nutrient loads in the XH Lagoon were mainly derived from riverine inputs and SGD, and the XH Lagoon behaved as a source for DIP, but a sink for DIN and DSi.

  13. Environmental enhancement of swine lagoons through influent treatment

    USDA-ARS?s Scientific Manuscript database

    Confined swine production generates large volumes of wastewater typically stored and treated in anaerobic lagoons. Failure of these lagoons during tropical storms in North Carolina along with major public environmental concerns led to a permanent state moratorium of construction of new anaerobic lag...

  14. Mass tree mortality leads to mangrove peat collapse at Bay Islands, Honduras after Hurricane Mitch

    USGS Publications Warehouse

    Cahoon, D.R.; Hensel, P.; Rybczyk, J.; McKee, K.L.; Proffitt, C.E.; Perez, B.C.

    2003-01-01

    We measured sediment elevation and accretion dynamics in mangrove forests on the islands of Guanaja and Roatan, Honduras, impacted by Hurricane Mitch in 1998 to determine if collapse of underlying peat was occurring as a result of mass tree mortality. Little is known about the balance between production and decomposition of soil organic matter in the maintenance of sediment elevation of mangrove forests with biogenic soils. Sediment elevation change measured with the rod surface elevation table from 18 months to 33 months after the storm differed significantly among low, medium and high wind impact sites. Mangrove forests suffering minimal to partial mortality gained elevation at a rate (5 mm yeara??1) greater than vertical accretion (2 mm yeara??1) measured from artificial soil marker horizons, suggesting that root production contributed to sediment elevation. Basin forests that suffered mass tree mortality experienced peat collapse of about 11 mm yeara??1 as a result of decomposition of dead root material and sediment compaction. Low soil shear strength and lack of root growth accompanied elevation decreases. Model simulations using the Relative Elevation Model indicate that peat collapse in the high impact basin mangrove forest would be 37 mm yeara??1 for the 2 years immediately after the storm, as root material decomposed. In the absence of renewed root growth, the model predicts that peat collapse will continue for at least 8 more years at a rate (7 mm yeara??1) similar to that measured (11 mm yeara??1). Mass tree mortality caused rapid elevation loss. Few trees survived and recovery of the high impact forest will thus depend primarily on seedling recruitment. Because seedling establishment is controlled in large part by sediment elevation in relation to tide height, continued peat collapse could further impair recovery rates.

  15. Hubble reveals heart of Lagoon Nebula

    NASA Image and Video Library

    2017-09-27

    Image release date September 22, 2010 To view a video of this image go here: www.flickr.com/photos/gsfc/5014452203 Caption: A spectacular new NASA/ESA Hubble Space Telescope image reveals the heart of the Lagoon Nebula. Seen as a massive cloud of glowing dust and gas, bombarded by the energetic radiation of new stars, this placid name hides a dramatic reality. The Advanced Camera for Surveys (ACS) on the NASA/ESA Hubble Space Telescope has captured a dramatic view of gas and dust sculpted by intense radiation from hot young stars deep in the heart of the Lagoon Nebula (Messier 8). This spectacular object is named after the wide, lagoon-shaped dust lane that crosses the glowing gas of the nebula. This structure is prominent in wide-field images, but cannot be seen in this close-up. However the strange billowing shapes and sandy texture visible in this image make the Lagoon Nebula’s watery name eerily appropriate from this viewpoint too. Located four to five thousand light-years away, in the constellation of Sagittarius (the Archer), Messier 8 is a huge region of star birth that stretches across one hundred light-years. Clouds of hydrogen gas are slowly collapsing to form new stars, whose bright ultraviolet rays then light up the surrounding gas in a distinctive shade of red. The wispy tendrils and beach-like features of the nebula are not caused by the ebb and flow of tides, but rather by ultraviolet radiation’s ability to erode and disperse the gas and dust into the distinctive shapes that we see. In recent years astronomers probing the secrets of the Lagoon Nebula have found the first unambiguous proof that star formation by accretion of matter from the gas cloud is ongoing in this region. Young stars that are still surrounded by an accretion disc occasionally shoot out long tendrils of matter from their poles. Several examples of these jets, known as Herbig-Haro objects, have been found in this nebula in the last five years, providing strong support for

  16. Lagoons and Reefs of New Caledonia

    NASA Image and Video Library

    2017-09-27

    NASA image acquired May 10, 2001 In July 2008, the United Nations Educational, Scientific, and Cultural Organization (UNESCO) added 27 new areas to its list of World Heritage sites. One of those areas included the lagoons of New Caledonia. Some 1,200 kilometers (750 miles) east of Australia, this French-governed archipelago contains the world’s third-largest coral reef structure. The coral reefs enclose the waters near the islands in shallow lagoons of impressive biodiversity. On May 10, 2001, the Enhanced Thematic Mapper Plus on NASA’s Landsat 7 satellite captured this image of Île Balabio, off the northern tip of Grande Terra, New Caledonia’s main island. In this natural-color image, the islands appear in shades of green and brown—mixtures of vegetation and bare ground. The surrounding waters range in color from pale aquamarine to deep blue, and the color differences result from varying depths. Over coral reef ridges and sand bars, the water is shallowest and palest in color. Darker shades of blue characterize deeper waters. Reef-enclosed, shallow waters surround Île Balabio, and a larger, semi-enclosed lagoon appears immediately east of that island. Immediately north of Grande Terra, unenclosed, deeper waters predominate. The coral reefs around New Caledonia support an unusual diversity of species, including large numbers of predators and big fish, turtles, and the world’s third-largest dugong population. NASA image created by Jesse Allen, using Landsat data provided by the United States Geological Survey. Caption by Michon Scott. Instrument: Landsat 7 - ETM+ Credit: NASA/GSFC/Landsat NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

  17. Clipperton, a possible future for atoll lagoons

    NASA Astrophysics Data System (ADS)

    Charpy, L.; Rodier, M.; Couté, A.; Perrette-Gallet, C.; Bley-Loëz, C.

    2010-09-01

    Closure of the Clipperton Island atoll (10°17' N 109°13' W), now a meromictic lake, is estimated to have occurred between 1839 and 1849. It was still closed in 2005. Brackish waters in the upper layer (0-10 m) were oxygenated, while saline waters in the deep layer (>20 m) were anoxic. Allowing for the methodological difficulties of earlier measurements, the physical characteristics of the lagoon did not seem to have changed significantly since the last expedition (1980). The intermediate layer between brackish and saline waters was characterized by a strong density gradient and a temperature inversion of up to 1.6°C. Microbial activity, water exchange between the deep layer and surrounding oceanic waters and the geothermal flux hypothesis are discussed. The low DIN and SRP concentrations observed in the upper layer, despite high nutrient input by seabird droppings, reflect the high nutrient uptake by primary producers as attested by the elevated overall gross primary production (6.6 g C m-2 day-1), and high suspended photosynthetic biomass (2.23 ± 0.23 μg Chl a l-1) and production (263 ± 27 μg C l-1 day-1). Phytoplankton composition changed in 67 years with the advent of new taxa and the disappearance of previously recorded species. The freshwater phytoplanktonic community comprised 43 taxa: 37 newly identified during the expedition and 6 previously noted; 16 species previously found were not seen in 2005. The closure of the lagoon, combined with the positive precipitation-evaporation budget characteristic of the region, has induced drastic changes in lagoon functioning compared with other closed atolls.

  18. Toward homogenization of Mediterranean lagoons and their loss of hydrodiversity

    NASA Astrophysics Data System (ADS)

    Ferrarin, Christian; Bajo, Marco; Bellafiore, Debora; Cucco, Andrea; De Pascalis, Francesca; Ghezzo, Michol; Umgiesser, Georg

    2014-08-01

    Lagoons are considered to be the most valuable systems of the Mediterranean coastal area, with crucial ecological, historical, economical, and social relevance. Climate change strongly affects coastal areas and can deeply change the status of transitional areas like lagoons. Herein we investigate the hydrological response of 10 Mediterranean lagoons to climate change by means of numerical models. Our results suggest that Mediterranean lagoons amplify the salinity and temperature changes expected for the open sea. Moreover, numerical simulations indicate that there will be a general loss of intralagoon and interlagoon variability of their physical properties. Therefore, as a result of climate change, we see on Mediterranean lagoons an example of a common process that in future may effect many coastal environments: that of homogenization of the physical characteristics with a tendency toward marinization.

  19. Macroalgae, nutrient cycles, and pollutants in the lagoon of Venice

    SciTech Connect

    Sfriso, A.; Pavoni, B.; Marcomini, A.; Orio, A.A. )

    1992-12-01

    The Lagoon of Venice is a wide, shallow coastal basin that extends for about 50 km along the northwest coast of the Adriatic Sea. The lagoon has been substantially modified through the actions of man over the last century through the artificial control of the hydraulic dynamics of the lagoon including the construction of channels to facilitate navigation. The lagoon is subjected to considerable pollutant loading through the drainage of land under cultivation, municipal sewage, and industrial effluents. In this paper are reported the results of observations designed to document recent changes in macroalgal species composition, seasonal cycles of primary producers and nutrient levels, and the effects of the macroalgal community on concentrations of organic and inorganic pollutants. The dominant macroalgae in the lagoon was Ulva rigida, and the levels of plant nutrients and pollutants were influenced by the seasonal cycles of the macroalgal community. 44 refs., 11 figs., 2 tabs.

  20. A global predictive model of carbon in mangrove soils

    NASA Astrophysics Data System (ADS)

    Jardine, Sunny L.; Siikamäki, Juha V.

    2014-10-01

    Mangroves are among the most threatened and rapidly vanishing natural environments worldwide. They provide a wide range of ecosystem services and have recently become known for their exceptional capacity to store carbon. Research shows that mangrove conservation may be a low-cost means of reducing CO2 emissions. Accordingly, there is growing interest in developing market mechanisms to credit mangrove conservation projects for associated CO2 emissions reductions. These efforts depend on robust and readily applicable, but currently unavailable, localized estimates of soil carbon. Here, we use over 900 soil carbon measurements, collected in 28 countries by 61 independent studies, to develop a global predictive model for mangrove soil carbon. Using climatological and locational data as predictors, we explore several predictive modeling alternatives, including machine-learning methods. With our predictive model, we construct a global dataset of estimated soil carbon concentrations and stocks on a high-resolution grid (5 arc min). We estimate that the global mangrove soil carbon stock is 5.00 ± 0.94 Pg C (assuming a 1 meter soil depth) and find this stock is highly variable over space. The amount of carbon per hectare in the world’s most carbon-rich mangroves (approximately 703 ± 38 Mg C ha-1) is roughly a 2.6 ± 0.14 times the amount of carbon per hectare in the world’s most carbon-poor mangroves (approximately 272 ± 49 Mg C ha-1). Considerable within country variation in mangrove soil carbon also exists. In Indonesia, the country with the largest mangrove soil carbon stock, we estimate that the most carbon-rich mangroves contain 1.5 ± 0.12 times as much carbon per hectare as the most carbon-poor mangroves. Our results can aid in evaluating benefits from mangrove conservation and designing mangrove conservation policy. Additionally, the results can be used to project changes in mangrove soil carbon stocks based on changing climatological predictors, e.g. to

  1. Hydrological Classification, a Practical Tool for Mangrove Restoration

    PubMed Central

    Van Loon, Anne F.; Te Brake, Bram; Van Huijgevoort, Marjolein H. J.; Dijksma, Roel

    2016-01-01

    Mangrove restoration projects, aimed at restoring important values of mangrove forests after degradation, often fail because hydrological conditions are disregarded. We present a simple, but robust methodology to determine hydrological suitability for mangrove species, which can guide restoration practice. In 15 natural and 8 disturbed sites (i.e. disused shrimp ponds) in three case study regions in south-east Asia, water levels were measured and vegetation species composition was determined. Using an existing hydrological classification for mangroves, sites were classified into hydrological classes, based on duration of inundation, and vegetation classes, based on occurrence of mangrove species. For the natural sites hydrological and vegetation classes were similar, showing clear distribution of mangrove species from wet to dry sites. Application of the classification to disturbed sites showed that in some locations hydrological conditions had been restored enough for mangrove vegetation to establish, in some locations hydrological conditions were suitable for various mangrove species but vegetation had not established naturally, and in some locations hydrological conditions were too wet for any mangrove species (natural or planted) to grow. We quantified the effect that removal of obstructions such as dams would have on the hydrology and found that failure of planting at one site could have been prevented. The hydrological classification needs relatively little data, i.e. water levels for a period of only one lunar tidal cycle without additional measurements, and uncertainties in the measurements and analysis are relatively small. For the study locations, the application of the hydrological classification gave important information about how to restore the hydrology to suitable conditions to improve natural regeneration or to plant mangrove species, which could not have been obtained by estimating elevation only. Based on this research a number of recommendations

  2. Hydrological Classification, a Practical Tool for Mangrove Restoration.

    PubMed

    Van Loon, Anne F; Te Brake, Bram; Van Huijgevoort, Marjolein H J; Dijksma, Roel

    2016-01-01

    Mangrove restoration projects, aimed at restoring important values of mangrove forests after degradation, often fail because hydrological conditions are disregarded. We present a simple, but robust methodology to determine hydrological suitability for mangrove species, which can guide restoration practice. In 15 natural and 8 disturbed sites (i.e. disused shrimp ponds) in three case study regions in south-east Asia, water levels were measured and vegetation species composition was determined. Using an existing hydrological classification for mangroves, sites were classified into hydrological classes, based on duration of inundation, and vegetation classes, based on occurrence of mangrove species. For the natural sites hydrological and vegetation classes were similar, showing clear distribution of mangrove species from wet to dry sites. Application of the classification to disturbed sites showed that in some locations hydrological conditions had been restored enough for mangrove vegetation to establish, in some locations hydrological conditions were suitable for various mangrove species but vegetation had not established naturally, and in some locations hydrological conditions were too wet for any mangrove species (natural or planted) to grow. We quantified the effect that removal of obstructions such as dams would have on the hydrology and found that failure of planting at one site could have been prevented. The hydrological classification needs relatively little data, i.e. water levels for a period of only one lunar tidal cycle without additional measurements, and uncertainties in the measurements and analysis are relatively small. For the study locations, the application of the hydrological classification gave important information about how to restore the hydrology to suitable conditions to improve natural regeneration or to plant mangrove species, which could not have been obtained by estimating elevation only. Based on this research a number of recommendations

  3. Associational resistance protects mangrove leaves from crab herbivory

    NASA Astrophysics Data System (ADS)

    Erickson, Amy A.; Bell, Susan S.; Dawes, Clinton J.

    2012-05-01

    While associational defenses have been well documented in many plant and algal ecosystems, this study is the first to document associational resistance in mangroves. Mangrove tree crab (Aratus pisonii) density and herbivory on three life-stages of the red mangrove (Rhizophora mangle) were documented in pure red versus mixed-species and predominantly non-red mangrove stands containing black (Avicennia germinans) and white (Laguncularia racemosa) mangroves in 1999-2000 in Tampa Bay, Florida. This study first established that R. mangle is the focal species in the context of associational resistance because it is damaged more than either of the other mangrove species. Next, it was hypothesized that crab density and leaf damage on R. mangle would be lower when in mixed-species and predominantly non-red versus red mangrove stands. A non-significant trend suggested that crab density varies among stands, and crab damage on R. mangle leaves was significantly lower in mixed-species and non-red stands. Mechanisms to explain associational resistance were examined. Positive Pearson correlations between the percent of adult R. mangle in a stand and both crab density and R. mangle leaf damage provided support for the resource concentration hypothesis. Limited support was found for the attractant-decoy hypothesis because the total amount of damaged leaves of all mangrove species combined typically differed among stands, suggesting that crabs were not shifting to alternative mangrove species to offset reduced availability of R. mangle leaves. Finally, while R. mangle seedlings were shorter in non-red stands compared to others, intra-specific differences in R. mangle leaf chemistry and sclerophylly among stands failed to explain associational patterns. These combined results argue for the need for additional experiments to elucidate mechanisms responsible for defensive plant associations in mangrove ecosystems and to determine whether such associations could be of use in mangrove

  4. Polarimetric SAR Interferometry Evaluation in Mangroves

    NASA Technical Reports Server (NTRS)

    Lee, Seung-Kuk; Fatoyinbo,Temilola; Osmanoglu, Batuhan; Sun, Guoqing

    2014-01-01

    TanDEM-X (TDX) enables to generate an interferometric coherence without temporal decorrelation effect that is the most critical factor for a successful Pol-InSAR inversion, as have recently been used for forest parameter retrieval. This paper presents mangrove forest height estimation only using single-pass/single-baseline/dual-polarization TDX data by means of new dual-Pol-InSAR inversion technique. To overcome a lack of one polarization in a conventional Pol- InSAR inversion (i.e. an underdetermined problem), the ground phase in the Pol-InSAR model is directly estimated from TDX interferograms assuming flat underlying topography in mangrove forest. The inversion result is validated against lidar measurement data (NASA's G-LiHT data).

  5. Seedling establishment in a dynamic sedimentary environment: a conceptual framework using mangroves.

    PubMed

    Balke, Thorsten; Webb, Edward L; van den Elzen, Eva; Galli, Demis; Herman, Peter M J; Bouma, Tjeerd J

    2013-06-01

    1. Vegetated biogeomorphic systems (e.g. mangroves, salt marshes, dunes, riparian vegetation) have been intensively studied for the impact of the biota on sediment transport processes and the resulting self-organization of such landscapes. However, there is a lack of understanding of physical disturbance mechanisms that limit primary colonization in active sedimentary environments. 2. This study elucidates the effect of sediment disturbance during the seedling stage of pioneer vegetation, using mangroves as a model system. We performed mesocosm experiments that mimicked sediment disturbance as (i) accretion/burial of plants and (ii) erosion/excavation of plants of different magnitudes and temporal distribution in combination with water movement and inundation stress. 3. Cumulative sediment disturbance reduced seedling survival, with the faster-growing Avicennia alba showing less mortality than the slower-growing Sonneratia alba. The presence of the additional stressors (inundation and water movement) predominantly reduced the survival of S. alba. 4. Non-lethal accretion treatments increased shoot biomass of the seedlings, whereas non-lethal erosion treatments increased root biomass allocation. This morphological plasticity in combination with the abiotic disturbance history determined how much maximum erosion the seedlings were able to withstand. 5.Synthesis and applications. Seedling survival in dynamic sedimentary environments is determined by the frequency and magnitude of sediment accretion or erosion events, with non-lethal events causing feedbacks to seedling stability. Managers attempting restoration of mangroves, salt marshes, dunes and riparian vegetation should recognize sediment dynamics as a main bottleneck to primary colonization. The temporal distribution of erosion and accretion events has to be evaluated against the ability of the seedlings to outgrow or adjust to disturbances. Our results suggest that selecting fast-growing pioneer species and

  6. Denitrification in anaerobic lagoons used to treat swine wastewater.

    PubMed

    Hunt, P G; Matheny, T A; Ro, K S; Vanotti, M B; Ducey, T F

    2010-01-01

    Anaerobic lagoons are commonly used for the treatment of swine wastewater. Although these lagoons were once thought to be relatively simple, their physical, chemical, and biological processes are very complex. This study of anaerobic lagoons had two objectives: (i) to quantify denitrification enzyme activity (DEA) and (ii) to evaluate the influence of lagoon characteristics on the DEA. The DEA was measured by the acetylene inhibition method. Wastewater samples and physical and chemical measurements were taken from the wastewater column of nine anaerobic swine lagoons from May 2006 to May 2009. These lagoons were typical for anaerobic swine lagoons in the Carolinas relative to their size, operation, and chemical and physical characteristics. Their mean value for DEA was 87 mg N2O-N m(-3) d(-1). In a lagoon with 2-m depth, this rate of DEA would be compatible with 1.74 kg N ha(-1) d(-1) When nonlimiting nitrate was added, the highest DEA was compatible with 4.38 kg N ha(-1) d(-1) loss. Using stepwise regression for this treatment, the lagoon characteristics (i.e., soluble organic carbon, total nitrogen, temperature, and NO3-N) provided a final step model R2 of 0.69. Nitrous oxide from incomplete denitrification was not a significant part of the system nitrogen balance. Although alternate pathways of denitrification may exist within or beneath the wastewater column, this paper documents the lack of sufficient denitrification enzyme activity within the wastewater column of these anaerobic lagoons to support large N2 gas losses via classical nitrification and denitrification.

  7. The Story of Mangrove Depletion: Using Socioscientific Cases to Promote Ocean Literacy

    ERIC Educational Resources Information Center

    Luther, Rachel A.; Tippins, Deborah J.; Bilbao, Purita P.; Tan, Andrew; Gelvezon, Ruth L.

    2013-01-01

    The value of mangroves and mangrove ecosystems has not always been recognized. In fact, mangroves were historically regarded largely as wastelands with little or no value. Over time, humans began to recognize the multiple ways in which they could be used, particularly through development, making the mangrove ecosystem vulnerable to destruction and…

  8. Mangrove Forests: a Tough System to Invade but an Easy one to Rehabilitate

    Treesearch

    ARIEL E. LUGO

    1998-01-01

    Mangrove forests are tough ecosystems to invade because few species can tolerate the hydrological and edaphic conditions that prevail in mangrove habitats. The small pantropical mangrove species pool is also the basis for asserting that mangrove forests are easy to rehabilitate, at least in terms of tree species composition. The high complexity of the animal and...

  9. Coastal regime shifts: rapid responses of coastal wetlands to changes in mangrove cover.

    PubMed

    Guo, Hongyu; Weaver, Carolyn; Charles, Sean P; Whitt, Ashley; Dastidar, Sayantani; D'Odorico, Paolo; Fuentes, Jose D; Kominoski, John S; Armitage, Anna R; Pennings, Steven C

    2017-03-01

    Global changes are causing broad-scale shifts in vegetation communities worldwide, including coastal habitats where the borders between mangroves and salt marsh are in flux. Coastal habitats provide numerous ecosystem services of high economic value, but the consequences of variation in mangrove cover are poorly known. We experimentally manipulated mangrove cover in large plots to test a set of linked hypotheses regarding the effects of changes in mangrove cover. We found that changes in mangrove cover had strong effects on microclimate, plant community, sediment accretion, soil organic content, and bird abundance within 2 yr. At higher mangrove cover, wind speed declined and light interception by vegetation increased. Air and soil temperatures had hump-shaped relationships with mangrove cover. The cover of salt marsh plants decreased at higher mangrove cover. Wrack cover, the distance that wrack was distributed from the water's edge, and sediment accretion decreased at higher mangrove cover. Soil organic content increased with mangrove cover. Wading bird abundance decreased at higher mangrove cover. Many of these relationships were non-linear, with the greatest effects when mangrove cover varied from zero to intermediate values, and lesser effects when mangrove cover varied from intermediate to high values. Temporal and spatial variation in measured variables often peaked at intermediate mangrove cover, with ecological consequences that are largely unexplored. Because different processes varied in different ways with mangrove cover, the "optimum" cover of mangroves from a societal point of view will depend on which ecosystem services are most desired.

  10. The Story of Mangrove Depletion: Using Socioscientific Cases to Promote Ocean Literacy

    ERIC Educational Resources Information Center

    Luther, Rachel A.; Tippins, Deborah J.; Bilbao, Purita P.; Tan, Andrew; Gelvezon, Ruth L.

    2013-01-01

    The value of mangroves and mangrove ecosystems has not always been recognized. In fact, mangroves were historically regarded largely as wastelands with little or no value. Over time, humans began to recognize the multiple ways in which they could be used, particularly through development, making the mangrove ecosystem vulnerable to destruction and…

  11. Carbon cycling and storage in mangrove forests.

    PubMed

    Alongi, Daniel M

    2014-01-01

    Mangroves are ecologically and economically important forests of the tropics. They are highly productive ecosystems with rates of primary production equal to those of tropical humid evergreen forests and coral reefs. Although mangroves occupy only 0.5% of the global coastal area, they contribute 10-15% (24 Tg C y(-1)) to coastal sediment carbon storage and export 10-11% of the particulate terrestrial carbon to the ocean. Their disproportionate contribution to carbon sequestration is now perceived as a means for conservation and restoration and a way to help ameliorate greenhouse gas emissions. Of immediate concern are potential carbon losses to deforestation (90-970 Tg C y(-1)) that are greater than these ecosystems' rates of carbon storage. Large reservoirs of dissolved inorganic carbon in deep soils, pumped via subsurface pathways to adjacent waterways, are a large loss of carbon, at a potential rate up to 40% of annual primary production. Patterns of carbon allocation and rates of carbon flux in mangrove forests are nearly identical to those of other tropical forests.

  12. Carbon Cycling and Storage in Mangrove Forests

    NASA Astrophysics Data System (ADS)

    Alongi, Daniel M.

    2014-01-01

    Mangroves are ecologically and economically important forests of the tropics. They are highly productive ecosystems with rates of primary production equal to those of tropical humid evergreen forests and coral reefs. Although mangroves occupy only 0.5% of the global coastal area, they contribute 10-15% (24 Tg C y-1) to coastal sediment carbon storage and export 10-11% of the particulate terrestrial carbon to the ocean. Their disproportionate contribution to carbon sequestration is now perceived as a means for conservation and restoration and a way to help ameliorate greenhouse gas emissions. Of immediate concern are potential carbon losses to deforestation (90-970 Tg C y-1) that are greater than these ecosystems' rates of carbon storage. Large reservoirs of dissolved inorganic carbon in deep soils, pumped via subsurface pathways to adjacent waterways, are a large loss of carbon, at a potential rate up to 40% of annual primary production. Patterns of carbon allocation and rates of carbon flux in mangrove forests are nearly identical to those of other tropical forests.

  13. Heterogeneity of elemental composition and natural abundance of stables isotopes of C and N in soils and leaves of mangroves at their southernmost West Atlantic range.

    PubMed

    Tognella, M M P; Soares, M L G; Cuevas, E; Medina, E

    2016-01-01

    Mangrove communities were selected in the state of Santa Catarina, Brazil, near their southernmost limit of distribution, to study mineral nutrient relation in soils and plants. Communities included three true mangrove species, Rhizophora mangle, Laguncularia racemosa and Avicennia germinans, and two associated species, the fern Acrostichum danaeifolium, and the grass Spartina densiflora. The sites included communities in the lower Río Tavares near Florianopolis city, Sonho beach near Palhoça city, and the Santo Antonio lagoon. These sites included a full range of mangroves under humid climate where winter temperatures, instead of salinity, may be the main factor regulating their productive capacity and species composition. Soil salinity was determined by the concentration of soluble Na, and soil C and N were linearly correlated indicating their association in organic matter. Tavares site showed higher specific conductivity, and concentrations of Na and Mg in the soil layer below 40 cm depth, indicating larger influence of marine water. Isotopic signature of C increased with soil depth suggesting that microorganisms decomposing organic matter are releasing 13C depleted CO2. Nitrogen isotopic signature decreased with soil depth, indicating enrichment in 15N possibly as a result of denitrification in the upper soil layers. Mineral elements in leaf tissues showed A. schaueriana with higher concentrations of N, P, Na, K, Cu, Zn, and Na/Ca ratio. Spartina densiflora was characterized by the lowest N and K concentrations, and the highest concentrations of Al and Fe. Rhizophora mangle and L. racemosa had the highest Ca concentrations. Carbon isotopic signatures identified S. densiflora as a C4 plant, and A. schaueriana as the mangrove species occupying comparatively more water stressed microsites than the rest. Leaf nitrogen isotopic signatures were positive, in correspondence with the soil values. The results support the hypothesis that sites sampled were comparatively

  14. Herbicides implicated as the cause of severe mangrove dieback in the Mackay region, NE Australia: consequences for marine plant habitats of the GBR World Heritage Area.

    PubMed

    Duke, Norman C; Bell, Alicia M; Pederson, Dan K; Roelfsema, Chris M; Bengtson Nash, Susan

    2005-01-01

    Herbicides, particularly diuron, were correlated with severe and widespread dieback of the dominant mangrove, Avicennia marina (Forsk.) Vierh. var. eucalyptifolia (Val.) N.C. Duke (Avicenniaceae), its reduced canopy condition, and declines in seedling health within three neighbouring estuaries in the Mackay region of NE Australia. This unusual species-specific dieback, first observed in the early 1990s, had gotten notably worse by 2002 to affect >30 km(2) of mangroves in at least five adjacent estuaries in the region. Over the past century, agricultural production has responded well to the demands of increasing population with improvements in farm efficiency assisted by significant increases in the use of agricultural chemicals. However, with regular and episodic river flow events, these chemicals have sometimes found their way into estuarine and nearshore water and sediments where their effects on marine habitats have been largely unquantified. Investigations over the last three years in the Mackay region provide compelling evidence of diuron, and possibly other agricultural herbicides, as the most likely cause of the severe and widespread mangrove dieback. The likely consequences of such dieback included declines in coastal water quality with increased turbidity, nutrients and sediment deposition, as well as further dispersal of the toxic chemicals. The implications of such findings are immense since they describe not only the serious deterioration of protected and beneficial mangrove habitat but also the potential for significant direct and indirect effects on other highly-valued estuarine and marine habitats in the region, including seagrass beds and coral reefs of the Great Barrier Reef lagoon. This article reviews all key findings and observations to date and describes the essential correlative and causative evidence.

  15. Ecological Study of Lagoons Surrounding the John F. Kennedy Space Center, Brevard County, Florida . Volume 2; Theses and Project Reports

    NASA Technical Reports Server (NTRS)

    2017-01-01

    Many of the detailed studies done in connection with Ecological Study of the Lagoons surrounding the John F. Kennedy Space Port were performed as Master's Thesis investigations by various graduate students enrolled at F. I. T. during and subsequent to the report. The scope and purpose of what we came to call "the KSC Baseline Study" caught the imagination and interest of our student body. Many who were not financially or otherwise connected with the project found their inspiration in studies that were directly connected with project, and thus added materially to the totality of the knowledge gained. An example of one such study is the first article included in this Volume, A Master's Thesis study performed by Shen Phillip Chen, who chose the site for his investigation so that his results would correlate with and extend the results of others. In addition to the Master's Theses contained in this Volume, six other graduate studies must be acknowledged here as contributing to this Report, although they have not reached the stage of final publication. Ms. Sandra Fettes has completed a study of the amounts of five trace metals in mangrove leaves from plants at various locations around the Kennedy Space Center. Mr. Bernard Cohenour has isolated and identified a number of oil consuming bacteria endemic in the waters of the Indian Rivers. Mr. Charles Waterhouse has analyzed historic data of tidal gauges in the lagoonal area and correlated it with wind field records. Mr. Renkert Meyer has measured the vertical and horizontal currents of the lagoons and is attempting an interpretation of them in terms of the wind field as a driving force. Mr. Richard Campbell has measured the rate of nitrogen fixation in both the water columns and the sediments under them in the lagoons. Mr. Craig Weiderhold has measured thl3 annual variations in the populations of benthic invertebrates in the lagoons. An integral part of the F. I. T. curriculum is a requirement that each undergraduate

  16. Sludge Lagoons. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Sharman, Ronald M.

    This lesson describes three different types of sludge lagoons: (1) drying lagoons; (2) facultative lagoons; and (3) anaerobic lagoons. Normal operating sequence and equipment are also described. The lesson is designed to be used in sequence with the complete Sludge Treatment and Disposal Course #166 or as an independent lesson. The instructor's…

  17. Are fiddler crabs potentially useful ecosystem engineers in mangrove wastewater wetlands?

    PubMed

    Penha-Lopes, Gil; Bartolini, Fabrizio; Limbu, Samwel; Cannicci, Stefano; Kristensen, Erik; Paula, José

    2009-11-01

    The effect of different organic-rich sewage concentration (0%, 20% and 60% diluted in seawater) and absence or presence of mangrove trees on the survival, bioturbation activities and burrow morphology of fiddler crabs species was assessed. After 6 months, males of both species always showed higher survival ( approximately 80%) when compared to females ( approximately 20%). Crabs inhabiting pristine conditions achieved higher survival (67-87%) than those living in sewage-exposed mesocosms (40-71%). At 60% sewage loading, fiddler crabs processed less sediment (34-46%) during feeding and excavated slightly more sediment (45-80%) than at pristine conditions. While percent volume of the burrow chambers increased (13-66%) at contaminated mesocosms for both vegetation conditions, burrows were shallower (approximately 33%) in bare cells loaded with sewage. The results show that fiddler crabs presented moderate mortality levels in these artificial mangrove wetlands, but mainly in sewage impacted cells. However, they still function as ecosystem engineers through bioturbation activities and burrow construction.

  18. Research on the ecology and management of Micronesian mangroves

    Treesearch

    J.A. Allen

    1999-01-01

    Mangroves are a vitally important natural resource on the high islands of Micronesia. This importance is especially valid in the Federated States of Micronisa (FSM) and the Republic of Palau, where mangroves cover 10-15% of the total land area and are used heavily by islanders as sources of wood, crabs, fish, thatching material, and other products.

  19. The Economic Value of Mangroves: A Meta-Analysis

    Treesearch

    Marwa Salem; D. Evan Mercer

    2012-01-01

    This paper presents a synthesis of the mangrove ecosystem valuation literature through a meta-regression analysis. The main contribution of this study is that it is the first meta-analysis focusing solely on mangrove forests, whereas previous studies have included different types of wetlands. The number of studies included in the regression analysis is 44 for a total...

  20. Low Carbon sink capacity of Red Sea mangroves.

    PubMed

    Almahasheer, Hanan; Serrano, Oscar; Duarte, Carlos M; Arias-Ortiz, Ariane; Masque, Pere; Irigoien, Xabier

    2017-08-29

    Mangroves forests of Avicennia marina occupy about 135 km(2) in the Red Sea and represent one of the most important vegetated communities in this otherwise arid and oligotrophic region. We assessed the soil organic carbon (Corg) stocks, soil accretion rates (SAR; mm y(-1)) and soil Corg sequestration rates (g Corg m(-2) yr(-1)) in 10 mangrove sites within four locations along the Saudi coast of the Central Red Sea. Soil Corg density and stock in Red Sea mangroves were among the lowest reported globally, with an average of 4 ± 0.3 mg Corg cm(-3) and 43 ± 5 Mg Corg ha(-1) (in 1 m-thick soils), respectively. Sequestration rates of Corg, estimated at 3 ± 1 and 15 ± 1 g Corg m(-2) yr(-1) for the long (millennia) and short (last century) temporal scales, respectively, were also relatively low compared to mangrove habitats from more humid bioregions. In contrast, the accretion rates of Central Red Sea mangroves soils were within the range reported for global mangrove forests. The relatively low Corg sink capacity of Red Sea mangroves could be due to the extreme environmental conditions such as low rainfall, nutrient limitation and high temperature, reducing the growth rates of the mangroves and increasing soil respiration rates.

  1. Carbon stocks of mangroves within the Zambezi River Delta, Mozambique

    Treesearch

    Christina E. Stringer; Carl C. Trettin; Stanley J. Zarnoch; Wenwu Tang

    2015-01-01

    Mangroves are well-known for their numerous ecosystem services, including storing a globally significant C pool. There is increasing interest in the inclusion of mangroves in national climate change mitigation and adaptation plans in developing nations as they become involved with incentive programs for climate change mitigation. The quality and precision of data...

  2. Mangroves as alien species: the case of Hawaii

    Treesearch

    James A. Allen

    1998-01-01

    Prior to the early 1900s, there were no mangroves in the Hawaiian Archipelago. In 1902, Rhizophora mangle was introduced on the island of Molokai, primarily for the purpose of stabilizing coastal mud flats. This species is now well established in Hawaii, and is found on nearly all of the major islands. At least five other species of mangroves or...

  3. Global patterns in the poleward expansion of mangrove forests

    NASA Astrophysics Data System (ADS)

    Cavanaugh, K. C.; Feller, I. C.

    2016-12-01

    Understanding the processes that limit the geographic ranges of species is one of the central goals of ecology and biogeography. This issue is particularly relevant for coastal wetlands given that climate change is expected to lead to a `tropicalization' of temperate coastal and marine ecosystems. In coastal wetlands around the world, there have already been observations of mangroves expanding into salt marshes near the current poleward range limits of mangroves. However, there is still uncertainty regarding regional variability in the factors that control mangrove range limits. Here we used time series of Landsat satellite imagery to characterize patterns of mangrove abundance near their poleward range limits around the world. We tested the commonly held assumption that temporal variation in abundance should increase towards the edge of the range. We also compared variability in mangrove abundance to climate factors thought to set mangrove range limits (air temperature, water temperature, and aridity). In general, variability in mangrove abundance at range edges was high relative to range centers and this variability was correlated to one or more climate factors. However, the strength of these relationships varied among poleward range limits, suggesting that some mangrove range limits are control by processes other than climate, such as dispersal limitation.

  4. Santa Catarina Island mangroves 3: a new species of Fuscoporia.

    PubMed

    Baltazar, Juliano Marcon; Trierveiler-Pereira, Larissa; Loguercio-Leite, Clarice; Ryvarden, Leif

    2009-01-01

    Fuscoporia bifurcata is described from southern Brazil based on collections from mangrove areas on Santa Catarina Island, in the state of Santa Catarina. The new species is characterized by hymenial setae with a bifurcate or spiny apex. A description with illustrations, an updated key to species of Fuscoporia from southern Brazil and a key to species of Hymenochaetaceae reported from mangroves are provided.

  5. Estimating mangrove in Florida: trials monitoring rare ecosystems

    Treesearch

    Mark J. Brown

    2015-01-01

    Mangrove species are keystone components in coastal ecosystems and are the interface between forest land and sea. Yet, estimates of their area have varied widely. Forest Inventory and Analysis (FIA) data from ground-based sample plots provide one estimate of the resource. Initial FIA estimates of the mangrove resource in Florida varied dramatically from those compiled...

  6. Impact of cross-reef water fluxes on lagoon dynamics: a simple parameterization for coral lagoon circulation model, with application to the Ouano Lagoon, New Caledonia

    NASA Astrophysics Data System (ADS)

    Chevalier, Cristele; Sous, Damien; Devenon, Jean-Luc; Pagano, Marc; Rougier, Gilles; Blanchot, Jean

    2015-11-01

    This manuscript presents a combined experimental and numerical study of the impact of cross-reef fluxes on coral reef lagoon dynamics. The selected field site is the Ouano Lagoon (New Caledonia Island, France) in the South Western Pacific Ocean. Measurements of wave transformation above the reef and current profiles through passages and reef openings have been carried out during a 3-month survey. Data analysis reveals the preponderant roles played by both tides and waves on the lagoon dynamics. Based on field data, a simple parameterization of cross-reef fluxes is implemented in a coastal lagoon circulation model and a satisfactory agreement is found between parameterized model and field results. The model is thus used as a numerical experimental tool in order to analyse the cross-reef flows' possible influence on a narrow lagoon dynamics. The results highlight the importance of cross-reef fluxes induced by wave breaking over the reef barrier on the whole lagoon circulation and water properties.

  7. Hypertrophic lagoon management by sediment disturbance.

    PubMed

    Lenzi, Mauro; Birardi, Francesca; Calzolai, Roberto; Finoia, Maria Grazia; Marcone, Francesco; Nocciolini, Stefano; Roffilli, Rugiada; Sgroi, Sergio; Solari, Duccio

    2010-01-01

    Experimental control of eutrophication in a small coastal lagoon was attempted by means of sediment disturbance. A specially designed boat was used to resuspend the top 3 cm of sediment by a jets of air-water directed towards the bottom. This disturbance was carried out for 3 months in each of two areas with a surface area of 24 and 20 hectares respectively. In a total of 80 stations in these two areas and in two undisturbed areas of 16 and 20 ha, organic matter, porosity, density and redox potential were monitored in sediment bimonthly and free sulphides were monitored in water close to the bottom. Before, during and after disturbance, the impact of daily sediment resuspension on the water column was monitored monthly, as ammonium nitrogen (N-NH4), soluble reactive phosphorus (SRP), dissolved oxygen (DO) and pH. In the whole lagoon, sediment texture was determined at the start and at the end of the experiment in 120 stations, and seaweed (mainly Chaetomorpha linum and Lophosiphonia subadunca) and seagrass (Ruppia cirrhosa) biomasses were estimated in 42 stations every month. The results showed a stable organic matter content in disturbed areas and an increase in undisturbed areas, as well as an increase in seaweed in areas distant from disturbed areas. No significant effect of sediment resuspension on water column N-NH4, SRP, DO or pH was found.

  8. Acid Tar Lagoons: Management and Recovery

    NASA Astrophysics Data System (ADS)

    Bohers, Anna; Hroncová, Emília; Ladomerský, Juraj

    2017-04-01

    This contribution presents the issue with possibility of definitive removal of dangerous environmental burden in Slovakia - serious historical problem of two acid tar lagoons. In relation to their removal, no technology has been found so far - technologically and economically suitable, what caused problems with its management. Locality Predajná is well known in Slovakia by its character of contrasts: it is situated in the picturesque landscape of National Park buffer zone of Nízke Tatry, on the other site it is contaminated by 229 211m3 of acid tar with its characteristics of toxicity, carcinogenicity, teratogenicity, mutagenicity and toxicity especially for animals and plants. Acid tar in two landfills with depth of 1m in case of the first lagoon and 9,5m in case of the second lagoon is a waste product derived from operation of Petrochema Dubová - refinery and petrochemical plant whose activity was to process the crude oil through processes of sulfonation and adsorption technology for producing lubricating and special oils, synthetic detergents and special white oils for cosmetic and medical purposes. A part of acid tar was incinerated in two incineration plats. Concentration of SO2 in combustion gases was too high and it was not possible to decrease it under the value of 2000 mg.mn-3 [LADOMERSKÝ, J. - SAMEŠOVÁ, D.: Reduction in sulfur dioxide emissions waste gases of incineration plant. Acta facultatis ecologiae. 1999, p. 217-223]. That is why it was necessary to put them out of operation. Later, because of public opposition it was not possible to build a new incineration plat corresponding to the state of the art. Even though actual Slovak and European legislative for protection of environment against such impacts, neither of tried methods - bio or non-biologic treatment methods - was proved as suitable for processing or for recovery in the reason of different factors admission: i.e. strong aggressivity, difficulty with handling because of its sludgy and

  9. Trematodes associated with mangrove habitat in Puerto Rican salt marshes

    USGS Publications Warehouse

    Lafferty, K.D.; Hechinger, R.F.; Lorda, J.; Soler, L.

    2005-01-01

    Batillaria minima is a common snail in the coastal estuaries of Puerto Rico. This snail is host to a variety of trematodes, the most common being Cercaria caribbea XXXI, a microphallid species that uses crabs as second intermediate hosts. The prevalence of infection was higher (7.1%) near mangroves than on mudflats away from man-groves (1.4%). Similarly, there was a significant positive association between the proportion of a site covered with mangroves and the prevalence of the microphallid. The association between mangroves and higher trematode prevalence is most likely because birds use mangroves as perch sites and this results in local transmission to snails. ?? American Society of Parasitologists 2005.

  10. Metals in sediments of San Andres lagoon, Tamaulipas, Mexico

    SciTech Connect

    Vazquez, F.G.; Aguilera, L.G. ); Sharma, V.K. )

    1994-03-01

    Heavy metal pollution in water is generally associated with industrial and municipal discharges into rivers, estuaries and lagoons. Once metals are in the water column, they may be taken up by organisms, deposited in the sediments or remain for some period in the water itself. The deposition rate in sediments depends on, among other factors, metal concentration in surface sediments. The concentrations of heavy metals in sediments of coastal, estuarine and lagoon environments have been determined by many workers. For the past several years, we have been interested in determining trace and heavy metal concentrations in the lagoons in Mexico to establish the levels of metal pollution. The work reported here is the completion of our ongoing study in San Andres lagoon. San Andres lagoon is located north of two industrial ports, Tampico and Altamira. In this industrial zone, the basins of the Panuco and Tamesi Rivers are localized and have industrial effluent throughout the year. All these activities and the input of the Tigre River, which runs through an agricultural and cattle-raising region, may affect the biogeochemistry of the San Andres lagoon. In the present work, we report concentrations of Cd, Co, Cu, Fe, Mn, Ni, Zn and Pb in sediments of San Andres lagoon. The measurements were made in different seasons; Rain-84 (August-September 1984); North (October-December 1984); Dry (April 1985); and Rain-85 (April-June 1985). 13 refs., 1 fig., 2 tabs.

  11. Both riverine detritus and dissolved nutrients drive lagoon fisheries

    NASA Astrophysics Data System (ADS)

    Bonthu, Subbareddy; Ganguly, Dipnarayan; Ramachandran, Purvaja; Ramachandran, Ramesh; Pattnaik, Ajit K.; Wolanski, Eric

    2016-12-01

    The net ecosystem metabolism in lagoons has often been estimated from the net budget of dissolved nutrients. Such is the case of the LOICZ estuarine biogeochemistry nutrient budget model that considers riverine dissolved nutrients, but not riverine detritus. However the neglect of detritus can lead to inconsistencies; for instance, it results in an estimate of 5-10 times more seaward export of nutrients than there is import from rivers in Chilika Lagoon, India. To resolve that discrepancy the UNESCO estuarine ecohydrology model, that considers both dissolved nutrients and detritus, was used and, for Chilika Lagoon, it reproduced successfully the spatial distribution of salinity, dissolved nutrients, phytoplankton and zooplankton as well as the fish yield data. Thus the model suggests that the riverine input of both detritus and dissolved nutrients supports the pelagic food web. The model also reproduces well the observation of decreased fish yield when the mouth of the lagoon was choked in the 1990s, demonstrating the importance of the physics that determine the flushing rate of waterborne matter. Thus, both farming in the watershed by driving the nutrient and detritus inputs to the lagoon, and dredging and engineering management of the mouth by controlling the flushing rate of the lagoon, have a major influence on fish stocks in the lagoon.

  12. Multi-centennial scale precipitation and following lagoon ecosystem fluctuation in the Holocene reconstructed by East Korean Lagoon sediment analysis

    NASA Astrophysics Data System (ADS)

    Katsuki, K.; Yang, D. Y.; Lim, J.; Nahm, W. H.; Nakanishi, T.; Seto, K.; Otsuka, M.; Kashima, K.

    2014-12-01

    There are lagoons in the northern east coast of the South Korea, which were formed during the transgression period in the early Holocene. These lagoons shrank about 5-30 % during the first half of 20 century due to terrestrial sediment input from soil erosion in reclamation lands. However, buried lagoonal sediments record Holocene climate change. In this study, multi-centennial scale paleo-climate and paleo-ecosystem change were investigated by analysis of this buried and present lagoon deposits. Based on the diatom assemblage analysis of the sediment in the lagoon Maeho where it is the east coast lagoons in Korea, this lagoon was formed about 8,400 years ago, and halophilic diatoms showed high peaks at three times within the last 8,400 years. Timings of these peaks were well coincident with the high-sea level periods reported in the western Japan. It is considered that sea-level of the east coast in Korea also showed high at three times during the mid-late Holocene, and then, salinity of the lagoon increased in these periods. Except for such sea-level dependent change, salinity of the lagoon Maeho showed the multi-centennial (200 or 400 years) scale periodic variation. Magnetic susceptibility (MS) also showed the clear 400 years periodicity in the mid-late Holocene. When the MS showed high value, oligohalobous diatoms showed high value. However, halophilic diatoms and number of total diatom valves increased when the MS showed low value. This correspondence probably indicates that magnetic minerals flew into the lagoon with river fresh water, and then volume of fresh water inflow has changed with 400 years cycles. Such MS cycle was also confirmed in the sediments of other lagoons. Change of fresh water inflow should be not local event, was a part of regional environmental change. These results probably indicate that the precipitation on the northeastern South Korea has changed by the 400 years cycle. On the basis of lagoon bottom sediment, it made clear that the

  13. Organic carbon inventories in natural and restored Ecuadorian mangrove forests

    PubMed Central

    Bruno, John F.; Benninger, Larry; Alperin, Marc; de Dios Morales, Juan

    2014-01-01

    Mangroves can capture and store organic carbon and their protection and therefore their restoration is a component of climate change mitigation. However, there are few empirical measurements of long-term carbon storage in mangroves or of how storage varies across environmental gradients. The context dependency of this process combined with geographically limited field sampling has made it difficult to generalize regional and global rates of mangrove carbon sequestration. This has in turn hampered the inclusion of sequestration by mangroves in carbon cycle models and in carbon offset markets. The purpose of this study was to estimate the relative carbon capture and storage potential in natural and restored mangrove forests. We measured depth profiles of soil organic carbon content in 72 cores collected from six sites (three natural, two restored, and one afforested) surrounding Muisne, Ecuador. Samples up to 1 m deep were analyzed for organic matter content using loss-on-ignition and values were converted to organic carbon content using an accepted ratio of 1.72 (g/g). Results suggest that average soil carbon storage is 0.055 ± 0.002 g cm−3 (11.3 ± 0.8% carbon content by dry mass, mean ± 1 SE) up to 1 m deep in natural sites, and 0.058 ± 0.002 g cm−3 (8.0 ± 0.3%) in restored sites. These estimates are concordant with published global averages. Evidence of equivalent carbon stocks in restored and afforested mangrove patches emphasizes the carbon sink potential for reestablished mangrove systems. We found no relationship between sediment carbon storage and aboveground biomass, forest structure, or within-patch location. Our results demonstrate the long-term carbon storage potential of natural mangroves, high effectiveness of mangrove restoration and afforestation, a lack of predictability in carbon storage strictly based on aboveground parameters, and the need to establish standardized protocol for quantifying mangrove sediment carbon stocks. PMID:24883249

  14. Taking Root: Enduring Effect of Rhizosphere Bacterial Colonization in Mangroves

    PubMed Central

    Pinto, Fernando N.; Egas, Conceição; Almeida, Adelaide; Cunha, Angela; Mendonça-Hagler, Leda C. S.; Smalla, Kornelia

    2010-01-01

    Background Mangrove forests are of global ecological and economic importance, but are also one of the world's most threatened ecosystems. Here we present a case study examining the influence of the rhizosphere on the structural composition and diversity of mangrove bacterial communities and the implications for mangrove reforestation approaches using nursery-raised plants. Methodology/Principal Findings A barcoded pyrosequencing approach was used to assess bacterial diversity in the rhizosphere of plants in a nursery setting, nursery-raised transplants and native (non-transplanted) plants in the same mangrove habitat. In addition to this, we also assessed bacterial composition in the bulk sediment in order to ascertain if the roots of mangrove plants affect sediment bacterial composition. We found that mangrove roots appear to influence bacterial abundance and composition in the rhizosphere. Due to the sheer abundance of roots in mangrove habitat, such an effect can have an important impact on the maintenance of bacterial guilds involved in nutrient cycling and other key ecosystem functions. Surprisingly, we also noted a marked impact of initial nursery conditions on the rhizosphere bacterial composition of replanted mangrove trees. This result is intriguing because mangroves are periodically inundated with seawater and represent a highly dynamic environment compared to the more controlled nursery environment. Conclusions/Significance In as far as microbial diversity and composition influences plant growth and health, this study indicates that nursery conditions and early microbial colonization patterns of the replants are key factors that should be considered during reforestation projects. In addition to this, our results provide information on the role of the mangrove rhizosphere as a habitat for bacteria from estuarine sediments. PMID:21124923

  15. Measuring surface energy and evapotranspiration across Caribbean mangrove forests

    NASA Astrophysics Data System (ADS)

    Lagomasino, D.; Fatoyinbo, T. E.; Price, R.

    2014-12-01

    Coastal mangroves lose large amounts of water through evapotranspiration (ET) that can be equivalent to the amount of annual rainfall in certain years. Satellite remote sensing has been used to estimate surface energy and ET variability in many forested ecosystems, yet has been widely overlooked in mangrove forests. Using a combination of long-term datasets (30-year) acquired from the NASA Landsat 5 and 7 satellite databases, the present study investigated ET and surface energy balance variability between two mangrove forest sites in the Caribbean: 1) Everglades National Park (ENP; Florida, USA) and 2) Sian Ka'an Biosphere Reserve (SKBR; Quintana Roo, Mexico). A satellite-derived surface energy balance model was used to estimate ET in tall and scrub mangroves environments at ENP and SKBR. Results identified significant differences in soil heat flux measurements and ET between the tall and scrub mangrove environments. Scrub mangroves exhibited the highest soil heat flux coincident with the lowest biophysical indices (i.e., Fractional Vegetation Cover, Normalized Difference Vegetation Index, and Soil-Adjusted Vegetation Index) and ET rates. Mangrove damage and mortality was observed on the satellite images following strong tropical storms and associated with anthropogenic modifications and resulted in low values in spectral vegetation indices, higher soil heat flux, and higher ET. Recovery of the spectral characteristics, soil heat flux and ET was within 1-2 years following hurricane disturbance while, degradation caused by human disturbance persisted for many years. Remotely sensed ET of mangrove forests can provide estimates over a few decades and provide us with some understanding of how these environments respond to disturbances to the landscape in periods where no ground data exists or in locations that are difficult to access. Moreover, relationships between energy and water balance components developed for the coastal mangroves of Florida and Mexico could be

  16. Organic carbon inventories in natural and restored Ecuadorian mangrove forests.

    PubMed

    DelVecchia, Amanda G; Bruno, John F; Benninger, Larry; Alperin, Marc; Banerjee, Ovik; de Dios Morales, Juan

    2014-01-01

    Mangroves can capture and store organic carbon and their protection and therefore their restoration is a component of climate change mitigation. However, there are few empirical measurements of long-term carbon storage in mangroves or of how storage varies across environmental gradients. The context dependency of this process combined with geographically limited field sampling has made it difficult to generalize regional and global rates of mangrove carbon sequestration. This has in turn hampered the inclusion of sequestration by mangroves in carbon cycle models and in carbon offset markets. The purpose of this study was to estimate the relative carbon capture and storage potential in natural and restored mangrove forests. We measured depth profiles of soil organic carbon content in 72 cores collected from six sites (three natural, two restored, and one afforested) surrounding Muisne, Ecuador. Samples up to 1 m deep were analyzed for organic matter content using loss-on-ignition and values were converted to organic carbon content using an accepted ratio of 1.72 (g/g). Results suggest that average soil carbon storage is 0.055 ± 0.002 g cm(-3) (11.3 ± 0.8% carbon content by dry mass, mean ± 1 SE) up to 1 m deep in natural sites, and 0.058 ± 0.002 g cm(-3) (8.0 ± 0.3%) in restored sites. These estimates are concordant with published global averages. Evidence of equivalent carbon stocks in restored and afforested mangrove patches emphasizes the carbon sink potential for reestablished mangrove systems. We found no relationship between sediment carbon storage and aboveground biomass, forest structure, or within-patch location. Our results demonstrate the long-term carbon storage potential of natural mangroves, high effectiveness of mangrove restoration and afforestation, a lack of predictability in carbon storage strictly based on aboveground parameters, and the need to establish standardized protocol for quantifying mangrove sediment carbon stocks.

  17. Inhomogeneity of methane emissions from a dairy waste lagoon.

    PubMed

    Grant, Richard H; Boehm, Matthew T

    2015-11-01

    Methane (CH4) is the dominant greenhouse gas emitted by animal agriculture manure. Since the gas is relatively insoluble in water, it is concentrated in discrete bubbles that rise through waste lagoons and burst at the surface. This results in lagoon emissions that are inhomogeneous in both space and time. Emissions from a midwestern dairy waste lagoon were measured over 2 weeks to evaluate the spatial homogeneity of the source emissions and to compare two methods for measuring this inhomogeneous emission. Emissions were determined using an inverse dispersion model based on CH4 concentrations measured both by a single scanning tunable diode laser (TDL) aimed at a series of reflectors and by flame ionization detection (FID) gas chromatography on line-sampled air. Emissions were best estimated using scanned TDL concentrations over relatively short optical paths that collectively span the entire cross-wind width of the source, so as to provide both the best capture of discrete plumes from the bursting bubbles on the lagoon surface and the best detection of CH4 background concentrations. The lagoon emissions during the study were spatially inhomogeneous at hourly time scales. Partitioning the inhomogeneous source into two source regions reduced the estimated emissions of the overall lagoon by 57% but increased the variability. Consequently, it is important to assess the homogeneity of a source prior to measurements and final emissions calculation. Plans for measuring methane emissions from waste lagoons must take into account the spatial inhomogeneity of the source strength. The assumption of emission source homogeneity for a low-solubility gas such as CH4 emitted from an animal waste lagoon can result in significant emission overestimates. The entire breadth and length of the area source must be measured, preferably with multiple optical paths, for the detection of discrete plumes from the different emitting regions and for determining the background concentration

  18. Hydrogen Sulfide Emissions from Sow Farm Lagoons across Climates Zones.

    PubMed

    Grant, Richard H; Boehm, Matthew T; Lawrence, Alfred J; Heber, Albert J

    2013-11-01

    Hydrogen sulfide (HS) emissions were measured periodically over the course of 2 yr at three sow waste lagoons representing humid mesothermal (North Carolina, NC), humid microthermal (Indiana, IN), and semiarid (Oklahoma, OK) climates. Emissions were determined using a backward Lagrangian stochastic model in conjunction with line-sampled HS concentrations and measured turbulence. The median annual sow-specific (area-specific) lagoon emissions at the OK farm were approximately 1.6 g head [hd] d (5880 µg m s), whereas those at the IN and NC sow farms were 0.035 g hd d (130 µg m s), and 0.041 g hd d (260 µg m s), respectively. Hydrogen sulfide emissions generally increased with wind speed. The daily HS emissions from the OK lagoon were greatest during the first half of the year and decreased as the year progressed. Emissions were episodic at the NC and IN lagoons. The generally low emissions at the NC and IN lagoons were probably a result of significant populations of purple sulfur bacteria maintained in the humid mesothermal and humid microthermal climates. Most of the large HS emission events at the NC and IN lagoons appeared to be a result of either precipitation events or liquid pump-out events. The high emissions at the OK lagoon in a semiarid climate were largely a result of high wind speeds enhancing both lagoon and air boundary layer mixing. The climate (air temperature, winds, and precipitation) appeared to influence the HS emissions from lagoons. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  19. Prevalence and genetic profiles of Escherichia coli from mangroves and mangrove associated foods off Goa, India.

    PubMed

    Poharkar, Krupali V; Kerkar, Savita; Doijad, Swapnil P; Barbuddhe, S B

    2014-08-15

    A total of 120 samples comprising of water (45), sediment (45) and mangrove originated food (30) collected from mangrove ecosystems of Goa were screened for Escherichia coli employing ISO-16654 method. Seventy-one (59.16%) samples were positive for E. coli. The E. coli isolates were further characterized by serotyping, virulence gene profiling and pulsed field gel electrophoresis (PFGE). Water and sediment samples were analyzed for physico-chemical parameters. The serotypes reported were O1, O10, O13, O17, O36, O41, O50, O68, O105, O116, O141, O148, O159, O162 and rough types while, 23 strains could not be typed. The stx1 and stx2 genes were detected in 33(46.47%) and 16(22.53%) isolates, respectively. The XbaI restriction digestion patterns of the stx positive strains were diverse. Interestingly, few strains isolated from diarrheal patients and from water, sediment and food from mangrove sources were genetically similar. The study showed that the mangrove ecosystem could be a potential reservoir for pathogenic E. coli.

  20. Stress in mangrove forests: early detection and preemptive rehabilitation are essential for future successful worldwide mangrove forest management

    USGS Publications Warehouse

    Lewis, Roy R; Milbrandt, Eric C; Brown, Benjamin; Krauss, Ken W.; Rovai, Andre S; Beever, James W.; Flynn, Laura L

    2016-01-01

    Mangrove forest rehabilitation should begin much sooner than at the point of catastrophic loss. We describe the need for “mangrove forest heart attack prevention”, and how that might be accomplished in a general sense by embedding plot and remote sensing monitoring within coastal management plans. The major cause of mangrove stress at many sites globally is often linked to reduced tidal flows and exchanges. Blocked water flows can reduce flushing not only from the seaward side, but also result in higher salinity and reduced sediments when flows are blocked landward. Long-term degradation of function leads to acute mortality prompted by acute events, but created by a systematic propensity for long-term neglect of mangroves. Often, mangroves are lost within a few years; however, vulnerability is re-set decades earlier when seemingly innocuous hydrological modifications are made (e.g., road construction, blocked tidal channels), but which remain undetected without reasonable large-scale monitoring.

  1. A Century of changes for Razelm-Sinoe Lagoon System

    NASA Astrophysics Data System (ADS)

    Scrieciu, Marian-Albert; Stanica, Adrian

    2014-05-01

    A Century of changes for Razelm-Sinoe Lagoon System Marian-Albert Scrieciu (a), Adrian Stanica (a) (a) National Institute of Marine Geology and Geoecology e GeoEcoMar, Str. Dimitrie Onciul 23e25, Sector 2, 024053 Bucharest, Romania Razelm-Sinoe Lagoon System, situated in the NW part of the Black Sea, in tight connection with the Danube Delta, has been subject to major changes due to human interventions in the past century. These changes have resulted into a complete change of the Lagoon specific ecosystems compared to its pristine state. In its natural state, as brackish - transitional environment, Antipa (1894) mentions Razelm Lagoon as one of the places with the greatest fisheries around the Black Sea coast (about 1879 - 1884, there were approximately 10,000 fishermen, all working on the Razelm Sinoe Lagoon System). Starting with the end of the XIXth Century, new canals were dug and existing channels were dredged in order to develop tighter connections with the Danube River. The natural inlet of Portita was blocked four decades ago and connections between the various parts of the lagoon system were controlled by the building of locks and sluices. The 2 inlets of Sinoe Lagoon were also controlled during early 1980s. Under these conditions, the lagoon ecosystem changed from brackish towards freshwater, with major effects on the existing flora and fauna. The period of brutal interventions ended in 1989 and the Razelm-Sinoe Lagoon System became part of the Danube Delta Biosphere Reserve in 1991, with a strict policy of nature protection and restoration. Spatial planning has been the major management option for the entire reserve, lagoon system included. Plans for sustainable development of the Razelm-Sinoe Lagoon System have been built in a participative manner, involving the local stakeholders, as part of FP7 ARCH project. Special attention has been given to impacts of climate change. The study presents the vision for the development Razelm-Sinoe Lagoon System over

  2. Mangrove Rehabilitation and Intertidal Biodiversity: a Study in the Ranong Mangrove Ecosystem, Thailand

    NASA Astrophysics Data System (ADS)

    Macintosh, D. J.; Ashton, E. C.; Havanon, S.

    2002-09-01

    The diversity, abundance, biomass and community structure of crustacean and molluscan macrofauna were studied in the Ranong mangrove forest ecosystem on the Andaman Sea coast of southern Thailand. After a history of commercial exploitation the mangroves along the Klong Ngao tidal creek have been assigned conservation status within a new Ranong Biosphere Reserve established in 1997. Over the past 12 years, several areas of mangrove destroyed or degraded by wood harvesting, tin mining and aquaculture, have been rehabilitated on a pilot basis by planting monocultures of mangrove seedlings using four common local species (Rhizophora apiculata, R. mucronata, Bruguiera cyclindrica and Ceriops tagal). These plantation forests with different past management histories were compared with a natural, mixed, mature mangrove forest which has been conserved for about 40 years. Macrofauna were sampled within a 100 m2 vegetation quadrat in each study site. Crustaceans were sampled quantitatively by 3×15 min timed hand catches per site. Molluscs were sampled in 3× m2 quadrats positioned around three randomly selected trees in each vegetation quadrat. The lowest crustacean and molluscan diversity was recorded from the former tin mining site. The highest diversity was recorded from aRhizophora plantation in the natural mixed forest area for both crustaceans and molluscs. The vegetation community structure was not correlated with the environmental variables measured, or with macrofauna community structure. Of the environmental parameters chosen, the crustacean community structure was best expressed by shore level, while for molluscan diversity and abundance it was soil moisture content. The macrofauna community structure at the tin mining site was significantly different to the other sites, and was dominated by a single species of crab, Metaplax elegans. Grapsid crabs, especially sesarmid species, dominated over ocypodid crabs in the mature forest site, whereas Uca species and other

  3. Phosphorus metabolism in anthropogenically transformed lagoon ecosystems: The Comacchio lagoons (Ferrara, Italy)

    NASA Astrophysics Data System (ADS)

    Sorokin, Yuri I.; Dallocchio, Franco; Gelli, Fernando; Pregnolato, Luciano

    1996-06-01

    Inorganic phosphorus dynamics were investigated with the use of 32P in the hypertrophic Comacchio lagoons (NE Adriatic) during an extremely dense, quasi-permanent bloom of picocyanobacteria. Concentrations of dissolved inorganic phosphate (DIP) in waters of the blooming lagoons were usually near the detection limit (0.01 μmoles·dm -3). DIP uptake rates by microplankton at near-ambient concentrations (0.01 to 0.1 μmoles·dm -3) were in the range of 9.6 to 16.1 nmoles P·dm -3·min -1, and turnover times were 1.5 to 3 min. The turnover time was >40 h in the eutrophic coastal waters of the adjacent Adriatic Sea. The uptake rate of DIP depended on its initial concentration. In water samples artificially enriched with DIP, the uptake rate rose to its maximum of 0.10 to 0.13 μmoles P·dm -3·min -1 (or ˜6 to 7 μmoles·dm -3·h -1) when the initial concentration of DIP was elevated to 10 to 20 μmoles·dm -3. The potential capacity of microplankton in the water samples to consume and retain DIP was estimated at ˜25 μmoles·dm -3. Specific features are discussed of phosphorus metabolism in the anthropogenically transformed lagoon ecosystem with an anomalous food web with few animals.

  4. White pelicans swim in the lagoon

    NASA Technical Reports Server (NTRS)

    1999-01-01

    White pelicans search for a meal in the waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The habitat of white pelicans are marshy lakes along the Pacific and Texas coasts, wintering chiefly in coastal lagoons such as this one. They often capture fish cooperatively, forming a long line, beating their wings and driving the prey into shallow water. The 92,000-acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  5. White pelicans swim in the lagoon

    NASA Technical Reports Server (NTRS)

    1999-01-01

    White pelicans search for a meal in the waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The habitat of white pelicans are marshy lakes along the Pacific and Texas coasts, wintering chiefly in coastal lagoons such as this one. They often capture fish cooperatively, forming a long line, beating their wings and driving the prey into shallow water. The 92,000-acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  6. Self-generated morphology in lagoon reefs.

    PubMed

    Blakeway, David; Hamblin, Michael G

    2015-01-01

    The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia's Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves-specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef.

  7. Self-generated morphology in lagoon reefs

    PubMed Central

    Hamblin, Michael G.

    2015-01-01

    The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia’s Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves—specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef. PMID:26175962

  8. Surface Water Quality Survey of Northern Indian River Lagoon from Sebastian Inlet to Mosquito Lagoon

    NASA Astrophysics Data System (ADS)

    Weaver, R. J.; Webb, B. M.

    2012-12-01

    Following news of an emerging brown tide algal bloom in the northern Indian River Lagoon (IRL), researchers sought to gain insight into the surface water quality in the IRL, as well as the extent of the algae coverage. A Portable SeaKeeper from YSI, mounted to a personal watercraft-based coastal profiling system, autonomously collected and analyzed the surface water. The system operates by recording sample data every 12 seconds while continuously underway at speeds up to and greater than 50 km/hr. The researchers covered a transect that started at Sebastian Inlet and followed a zig-zag path extending up through the Haulover Canal and into the Mosquito Lagoon. The survey path covered 166.7 km, and collected 2248 samples. Along the way stops were made at water quality stations used by the Saint John's River Water Management District, so that the data collected can be incorporated into ongoing monitoring efforts. The system analyzed the surface water for dissolved oxygen, pH, chlorophyll-a, salinity, temperature, turbidity, refined fuels, and CDOM. In the two days following the lagoon survey, the inlets at Port Canaveral and Sebastian were also surveyed for tidal currents and hydrography. The IRL transect survey data recorded evidence of the southern extent of the algae bloom in both chlorophyll-a and pH levels. Visual evidence of the bloom was striking as the water in the northern IRL turned a milk chocolaty brown color. Chlorophyll-a levels in the two inlets suggested bloom activity at these locations; however this bloom was different. This oceanic bloom was a result of a persistent upwelling event along the East Florida shelf, and the color was a paler green-yellow. The near-synoptic nature of the comprehensive lagoon survey, conducted in just over 7 hours, allows researchers to obtain a better understanding of water quality in coastal lagoons. Elevated levels of salinity, temperature, and refined fuels in the northern IRL indicate a low exchange rate and absence

  9. Mercury methylation and demethylation in Hg-contaminated lagoon sediments (Marano and Grado Lagoon, Italy)

    NASA Astrophysics Data System (ADS)

    Hines, Mark E.; Poitras, Erin N.; Covelli, Stefano; Faganeli, Jadran; Emili, Andrea; Žižek, Suzana; Horvat, Milena

    2012-11-01

    Mercury (Hg) transformation activities and sulfate (SO42-) reduction were studied in sediments of the Marano and Grado Lagoons in the Northern Adriatic Sea region as part of the "MIRACLE" project. The lagoons, which are sites of clam (Tapes philippinarum) farming, have been receiving excess Hg from the Isonzo River for centuries. Marano Lagoon is also contaminated from a chlor-alkali plant. Radiotracer methods were used to measure mercury methylation (230Hg, 197Hg), methylmercury (MeHg) demethylation (14C-MeHg) and SO42- reduction (35S) in sediment cores collected in autumn, winter and summer. Mercury methylation rate constants ranged from near zero to 0.054 day-1, generally decreased with depth, and were highest in summer. Demethylation rate constants were much higher than methylation reaching values of ˜0.6 day-1 in summer. Demethylation occurred via the oxidative pathway, except in winter when the reductive pathway increased in importance in surficial sediments. Sulfate reduction was also most active in summer (up to 1600 nmol mL-1 day-1) and depth profiles reflected seasonally changing redox conditions near the surface. Methylation and demethylation rate constants correlated positively with SO42- reduction and pore-water Hg concentrations, and inversely with Hg sediment-water partition coefficients indicating the importance of SO42- reduction and Hg dissolution on Hg cycling. Hg transformation rates were calculated using rate constants and concentrations of Hg species. In laboratory experiments, methylation was inhibited by amendments of the SO42--reduction inhibitor molybdate and by nitrate. Lagoon sediments displayed a dynamic seasonal cycle in which Hg dissolution in spring/summer stimulated Hg methylation, which was followed by a net loss of MeHg in autumn from demethylation. Sulfate-reducing bacteria (SRB) tended to be responsible for methylation of Hg and the oxidative demethylation of MeHg. However, during winter in surficial sediments, iron

  10. VISTA Stares Deeply into the Blue Lagoon

    NASA Astrophysics Data System (ADS)

    2011-01-01

    This new infrared image of the Lagoon Nebula was captured as part of a five-year study of the Milky Way using ESO's VISTA telescope at the Paranal Observatory in Chile. This is a small piece of a much larger image of the region surrounding the nebula, which is, in turn, only one part of a huge survey. Astronomers are currently using ESO's Visible and Infrared Survey Telescope for Astronomy (VISTA) to scour the Milky Way's central regions for variable objects and map its structure in greater detail than ever before. This huge survey is called VISTA Variables in the Via Lactea (VVV) [1]. The new infrared image presented here was taken as part of this survey. It shows the stellar nursery called the Lagoon Nebula (also known as Messier 8, see eso0936), which lies about 4000-5000 light-years away in the constellation of Sagittarius (the Archer). Infrared observations allow astronomers to peer behind the veil of dust that prevents them from seeing celestial objects in visible light. This is because visible light, which has a wavelength that is about the same size as the dust particles, is strongly scattered, but the longer wavelength infrared light can pass through the dust largely unscathed. VISTA, with its 4.1-metre diameter mirror - the largest survey telescope in the world - is dedicated to surveying large areas of the sky at near-infrared wavelengths deeply and quickly. It is therefore ideally suited to studying star birth. Stars typically form in large molecular clouds of gas and dust, which collapse under their own weight. The Lagoon Nebula, however, is also home to a number of much more compact regions of collapsing gas and dust, called Bok globules [2]. These dark clouds are so dense that, even in the infrared, they can block the starlight from background stars. But the most famous dark feature in the nebula, for which it is named, is the lagoon-shaped dust lane that winds its way through the glowing cloud of gas. Hot, young stars, which give off intense

  11. Cage experiments in an East African mangrove forest: a synthesis

    NASA Astrophysics Data System (ADS)

    Schrijvers, J.; Vincx, M.

    1997-12-01

    The impact of epibenthos on endobenthos has frequently been investigated for temperate saltmarsh regions by using cage exclusion experiments. Although the insight into the function of the endobenthos of mangrove forests is crucial for their management, very few cage experiments have so far been carried out in such areas. The present paper summaries the results of such experiments in a typical East African mangrove forest at Gazi Bay about 60 km south of Mombasa, Kenya. Epibenthic animals were excluded for one year in two mangrove zones which differed in forest morphology and intertidal position ( Ceriops tagal and Avicennia marina). Environmental factors and meiobenthic and macrobenthic densities were followed in a randomised block design, and procedural and exclusion effects were statistically detected. In confronting the separate responses of all faunal groups in the two mangrove zones, this synthesis gives a better insight into the tropho-dynamical interactions than the earlier separate reports on the same experiment. The ecosystem of the mangrove zones and the competitive interactions within this system provided an ideal opportunity to discover the existence of two food systems. This confirmed a strong involvement of the majority of the endobenthos in an isolated decompositional pathway in the mangrove sediment. It became clear that this exploitative competition was more important than the epibenthic predation in structuring and regulating the global endobenthic community. This synthesis therefore both demonstrates the decisive role of the endobenthos as regenators of mangrove material, and suggests that endobenthos plays a minor role as prey for the demersal or pelagic carnivores.

  12. How mangrove forests adjust to rising sea level

    USGS Publications Warehouse

    Krauss, Ken W.; McKee, Karen L.; Lovelock, Catherine E.; Cahoon, Donald R.; Saintilan, Neil; Reef, Ruth; Chen, Luzhen

    2014-01-01

    Mangroves are among the most well described and widely studied wetland communities in the world. The greatest threats to mangrove persistence are deforestation and other anthropogenic disturbances that can compromise habitat stability and resilience to sea-level rise. To persist, mangrove ecosystems must adjust to rising sea level by building vertically or become submerged. Mangroves may directly or indirectly influence soil accretion processes through the production and accumulation of organic matter, as well as the trapping and retention of mineral sediment. In this review, we provide a general overview of research on mangrove elevation dynamics, emphasizing the role of the vegetation in maintaining soil surface elevations (i.e. position of the soil surface in the vertical plane). We summarize the primary ways in which mangroves may influence sediment accretion and vertical land development, for example, through root contributions to soil volume and upward expansion of the soil surface. We also examine how hydrological, geomorphological and climatic processes may interact with plant processes to influence mangrove capacity to keep pace with rising sea level. We draw on a variety of studies to describe the important, and often under-appreciated, role that plants play in shaping the trajectory of an ecosystem undergoing change.

  13. Mangrove succession enriches the sediment microbial community in South China

    PubMed Central

    Chen, Quan; Zhao, Qian; Li, Jing; Jian, Shuguang; Ren, Hai

    2016-01-01

    Sediment microorganisms help create and maintain mangrove ecosystems. Although the changes in vegetation during mangrove forest succession have been well studied, the changes in the sediment microbial community during mangrove succession are poorly understood. To investigate the changes in the sediment microbial community during succession of mangroves at Zhanjiang, South China, we used phospholipid fatty acid (PLFA) analysis and the following chronosequence from primary to climax community: unvegetated shoal; Avicennia marina community; Aegiceras corniculatum community; and Bruguiera gymnorrhiza + Rhizophora stylosa community. The PLFA concentrations of all sediment microbial groups (total microorganisms, fungi, gram-positive bacteria, gram-negative bacteria, and actinomycetes) increased significantly with each stage of mangrove succession. Microbial PLFA concentrations in the sediment were significantly lower in the wet season than in the dry season. Regression and ordination analyses indicated that the changes in the microbial community with mangrove succession were mainly associated with properties of the aboveground vegetation (mainly plant height) and the sediment (mainly sediment organic matter and total nitrogen). The changes in the sediment microbial community can probably be explained by increases in nutrients and microhabitat heterogeneity during mangrove succession. PMID:27265262

  14. Are global mangrove carbon stocks driven by rainfall?

    NASA Astrophysics Data System (ADS)

    Sanders, Christian J.; Maher, Damien T.; Tait, Douglas R.; Williams, Darren; Holloway, Ceylena; Sippo, James Z.; Santos, Isaac R.

    2016-10-01

    Mangrove forests produce significant amounts of organic carbon and maintain large carbon stocks in tidally inundated, anoxic soils. This work analyzes new and published data from 17 regions spanning a latitudinal gradient from 22°N to 38°S to assess some of the global drivers (temperature, tidal range, latitude, and rainfall) of mangrove carbon stocks. Mangrove forests from the tropics have larger carbon stocks (895 ± 90 t C ha-1) than the subtropics and temperate regions (547 ± 66 t C ha-1). A multiple regression model showed that 86% of the observed variability is associated with annual rainfall, which is the best predictor of mangrove ecosystem carbon stocks. Therefore, a predicted increase in rainfall along the tropical Indo-Pacific may increase mangrove forest carbon stocks. However, there are other potentially important factors that may regulate organic matter diagenesis, such as nutrient availability and pore water salinity. Our predictive model shows that if mangrove deforestation is halted, global mangrove forest carbon stocks could increase by almost 10% by 2115 as a result of increased rainfall in the tropics.

  15. Mapping the Philippines' mangrove forests using Landsat imagery

    USGS Publications Warehouse

    Long, Jordan; Giri, Chandra

    2011-01-01

    Current, accurate, and reliable information on the areal extent and spatial distribution of mangrove forests in the Philippines is limited. Previous estimates of mangrove extent do not illustrate the spatial distribution for the entire country. This study, part of a global assessment of mangrove dynamics, mapped the spatial distribution and areal extent of the Philippines’ mangroves circa 2000. We used publicly available Landsat data acquired primarily from the Global Land Survey to map the total extent and spatial distribution. ISODATA clustering, an unsupervised classification technique, was applied to 61 Landsat images. Statistical analysis indicates the total area of mangrove forest cover was approximately 256,185 hectares circa 2000 with overall classification accuracy of 96.6% and a kappa coefficient of 0.926. These results differ substantially from most recent estimates of mangrove area in the Philippines. The results of this study may assist the decision making processes for rehabilitation and conservation efforts that are currently needed to protect and restore the Philippines’ degraded mangrove forests.

  16. Mangrove succession enriches the sediment microbial community in South China.

    PubMed

    Chen, Quan; Zhao, Qian; Li, Jing; Jian, Shuguang; Ren, Hai

    2016-06-06

    Sediment microorganisms help create and maintain mangrove ecosystems. Although the changes in vegetation during mangrove forest succession have been well studied, the changes in the sediment microbial community during mangrove succession are poorly understood. To investigate the changes in the sediment microbial community during succession of mangroves at Zhanjiang, South China, we used phospholipid fatty acid (PLFA) analysis and the following chronosequence from primary to climax community: unvegetated shoal; Avicennia marina community; Aegiceras corniculatum community; and Bruguiera gymnorrhiza + Rhizophora stylosa community. The PLFA concentrations of all sediment microbial groups (total microorganisms, fungi, gram-positive bacteria, gram-negative bacteria, and actinomycetes) increased significantly with each stage of mangrove succession. Microbial PLFA concentrations in the sediment were significantly lower in the wet season than in the dry season. Regression and ordination analyses indicated that the changes in the microbial community with mangrove succession were mainly associated with properties of the aboveground vegetation (mainly plant height) and the sediment (mainly sediment organic matter and total nitrogen). The changes in the sediment microbial community can probably be explained by increases in nutrients and microhabitat heterogeneity during mangrove succession.

  17. Paleoecology of mangroves along the Sibun River, Belize

    NASA Astrophysics Data System (ADS)

    Monacci, Natalie M.; Meier-Grünhagen, Ursula; Finney, Bruce P.; Behling, Hermann; Wooller, Matthew J.

    2011-09-01

    This study examines a sediment core (SR-63) from a mangrove ecosystem along the Sibun River in Belize, which is subject to both changes in sea-level and in the characteristics of the river's drainage basin. Radiocarbon dates from the core show a decreased sedimentation rate from ~ 6 ka to 1 cal ka BP and a marked change in lithology from primarily mangrove peat to fluvial-derived material at ~ 2.5 cal ka BP. Changes in the sedimentation rates observed in mangrove ecosystems offshore have previously been attributed to changes in relative sea-level and the rate of sea-level rise. Pollen analyses show a decreased abundance of Rhizophora (red mangrove) pollen and an increased abundance of Avicennia (black mangrove) pollen and non-mangrove pollen coeval with the decreased sedimentation rates. Elemental ratios ([N:C] a) and stable isotope analyses (δ 15N and δ 13C) show that changes in the composition of the organic material are also coeval with the change in lithology. The decrease in sedimentation rate at the site of core SR-63 and at offshore sites supports the idea that regional changes in hydrology occurred during the Holocene in Belize, influencing both mainland and offshore mangrove ecosystems.

  18. Mangrove succession enriches the sediment microbial community in South China

    NASA Astrophysics Data System (ADS)

    Chen, Quan; Zhao, Qian; Li, Jing; Jian, Shuguang; Ren, Hai

    2016-06-01

    Sediment microorganisms help create and maintain mangrove ecosystems. Although the changes in vegetation during mangrove forest succession have been well studied, the changes in the sediment microbial community during mangrove succession are poorly understood. To investigate the changes in the sediment microbial community during succession of mangroves at Zhanjiang, South China, we used phospholipid fatty acid (PLFA) analysis and the following chronosequence from primary to climax community: unvegetated shoal; Avicennia marina community; Aegiceras corniculatum community; and Bruguiera gymnorrhiza + Rhizophora stylosa community. The PLFA concentrations of all sediment microbial groups (total microorganisms, fungi, gram-positive bacteria, gram-negative bacteria, and actinomycetes) increased significantly with each stage of mangrove succession. Microbial PLFA concentrations in the sediment were significantly lower in the wet season than in the dry season. Regression and ordination analyses indicated that the changes in the microbial community with mangrove succession were mainly associated with properties of the aboveground vegetation (mainly plant height) and the sediment (mainly sediment organic matter and total nitrogen). The changes in the sediment microbial community can probably be explained by increases in nutrients and microhabitat heterogeneity during mangrove succession.

  19. Impact of human interventions on mangrove ecosystem in spatial perspective

    NASA Astrophysics Data System (ADS)

    Rasyid, Abd.; Akbar AS, M.; Nurdin, Nurjannah; Jaya, Ilham; Ibrahim

    2016-11-01

    Climate change components that affect mangroves include changes in sea level, high water events, storms, precipitation, temperature, and oceanic circulation. Cumulative impacts of these factors have a distinct synergy with respect to an accelerated rate of mangrove degradation. development of coastal agricultural land and shrimp farming ponds in intertidal areas are considered as the major factors behind mangrove delineation. There is no agreement for the extensive of mangrove forest in Indonesia, but invarious forums it is usually used the number of 4.25 million ha for that. At approximately 9 years ago, the extensive vast of mangrove forest in Indonesia was about 4.13 million ha but now it is only 2.49 million ha (60%). The methodology of this study consisted of two main steps: (1) image analysis, and (2) post classification. The aim of this study is to analysis the human intervention base on spatial dynamic of mangrove. The study site was selected Sagara island in Spermonde Archipelago. The results of analyze shows that decreasing of mangrove is caused human intervention.

  20. How mangrove forests adjust to rising sea level.

    PubMed

    Krauss, Ken W; McKee, Karen L; Lovelock, Catherine E; Cahoon, Donald R; Saintilan, Neil; Reef, Ruth; Chen, Luzhen

    2014-04-01

    Mangroves are among the most well described and widely studied wetland communities in the world. The greatest threats to mangrove persistence are deforestation and other anthropogenic disturbances that can compromise habitat stability and resilience to sea-level rise. To persist, mangrove ecosystems must adjust to rising sea level by building vertically or become submerged. Mangroves may directly or indirectly influence soil accretion processes through the production and accumulation of organic matter, as well as the trapping and retention of mineral sediment. In this review, we provide a general overview of research on mangrove elevation dynamics, emphasizing the role of the vegetation in maintaining soil surface elevations (i.e. position of the soil surface in the vertical plane). We summarize the primary ways in which mangroves may influence sediment accretion and vertical land development, for example, through root contributions to soil volume and upward expansion of the soil surface. We also examine how hydrological, geomorphological and climatic processes may interact with plant processes to influence mangrove capacity to keep pace with rising sea level. We draw on a variety of studies to describe the important, and often under-appreciated, role that plants play in shaping the trajectory of an ecosystem undergoing change.

  1. Seasonal variation in a tropical lagoon with submarine groundwater discharges

    NASA Astrophysics Data System (ADS)

    Tenorio, L.; Gómez-Valdés, J.; Enriquez, C.; Treviño, C.; Marino-Tapia, I.; López-Aguiar, K.

    2013-05-01

    The Chelem-Chuburna-Yucalpeten lagoon system is located at 21°17'N and 89°40'W in the Yucatan peninsula, Mexico. Temperature, conductivity, sea level, atmospheric pressure, solar radiation, and wind speed measurements were recorded in this lagoon, during various oceanographic surveys within 2010-2012. During the experiments, which included diurnal variations during spring and neap tidal cycles, CTD profiles were collected in 35 oceanographic stations and moored instruments were deployed at strategic locations. The aim of this work is to investigate transitions of thermohaline properties in a tropical lagoon with submarine groundwater discharges (SGDs) to increase the knowledge of the principal processes that control circulation and mixing in this kind of bodies of water. Results show that the lagoon is saltier than the ocean in the dry season and the opposite pattern is observed in the rain season. During the rain season could be more freshwater supplied from SGDs.

  2. ANALYSIS OF SWINE LAGOONS AND GROUND WATER FOR ENVIRONMENTAL ESTROGENS

    EPA Science Inventory

    A method was developed for analysis of low levels of natural (estradiol, estrone, estriol) and synthetic (ethynylestradiol) estrogens in ground water and swine waste lagoon effluent. The method includes solid phase extraction of the estrogens, preparation of pentafluorobenzyl der...

  3. Region 8 NPDES Lagoon General Permit Notice of Intent Form

    EPA Pesticide Factsheets

    Adobe Acrobat fillable form of the Notice of Intent for Coverage under the EPA Region 8 Lagoon General Permit for Wastewater Systems located in Indian Country in Colorado, Montana, North Dakota, South Dakota, Utah and Wyoming.

  4. Nutrient removal from swine lagoon effluent by duckweed

    SciTech Connect

    Bergmann, B.A.; Cheng, J.; Classen, J.; Stomp, A.M.

    2000-04-01

    Three duckweed geographic isolates were grown on varying concentrations of swine lagoon effluent in a greenhouse to determine their ability to remove nutrients from the effluent. Duckweed biomass was harvested every other day over a 12-day period. Duckweed biomass production, nutrient loss from the swine lagoon effluent, and nutrient content of duckweed biomass were used to identify effluent concentrations/geographic isolate combinations that are effective in terms of nutrient utilization from swine lagoon effluent and production of healthy duckweed biomass. When Lemna minor geographic isolate 8627 was grown on 50% swine lagoon effluent, respective losses of TKN, NH{sub 3}-N, TP, OPO{sub 4}-P, TOC, K, Cu, and Zn were 83, 100, 49, 31, 68, 21, 28 and 67%.

  5. ANALYSIS OF SWINE LAGOONS AND GROUND WATER FOR ENVIRONMENTAL ESTROGENS

    EPA Science Inventory

    A method was developed for analysis of low levels of natural (estradiol, estrone, estriol) and synthetic (ethynylestradiol) estrogens in ground water and swine waste lagoon effluent. The method includes solid phase extraction of the estrogens, preparation of pentafluorobenzyl der...

  6. ANALYSIS OF SWINE LAGOONS AND GROUND WATER FOR ENVIRONMENTAL ESTROGENS

    EPA Science Inventory

    A method was developed for analysis of low levels of natural (estradiol, estrone, estriol) and synthetic (ethinyl estradiol) estrogens in ground water and swine waste lagoon effluent. The method includes solid phase extraction of the estrogens, preparation of pentafluorobenzyl de...

  7. 13. Sewage treatment lagoon, drainage control at center left, looking ...

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

    13. Sewage treatment lagoon, drainage control at center left, looking south - Ellsworth Air Force Base, Delta Flight, Launch Control Facility, County Road CS23A, North of Exit 127, Interior, Jackson County, SD

  8. 1. Oblique view: east side, from Condado Lagoon Beach on ...

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

    1. Oblique view: east side, from Condado Lagoon Beach on southeast (context) - Puente Guillermo Esteves, Spanning San Antonio Channel at PR-25 (Juan Ponce de Leon Avenue), San Juan, San Juan Municipio, PR

  9. ANALYSIS OF SWINE LAGOONS AND GROUND WATER FOR ENVIRONMENTAL ESTROGENS

    EPA Science Inventory

    A method was developed for analysis of low levels of natural (estradiol, estrone, estriol) and synthetic (ethinyl estradiol) estrogens in ground water and swine waste lagoon effluent. The method includes solid phase extraction of the estrogens, preparation of pentafluorobenzyl de...

  10. Arsenic pollution in Patos Lagoon estuarine sediments, Brazil.

    PubMed

    Mirlean, Nicolai; Andrus, Vlad E; Baisch, Paulo; Griep, Gilberto; Casartelli, Maria R

    2003-11-01

    Arsenic distribution in sediments of the Mirim-Patos lagoonal system is investigated. Deposits of fresh water Mirim Lagoon and those of the fresh water part of the Patos Lagoon contain 2.5 and 7.7 mg kg(-1), respectively, on average of total arsenic. In contrast, estuarine sediments of the Patos Lagoon are evidently contaminated by arsenic in high concentrations (up to 50 mg kg(-1)), and about 80% of the arsenic there is found in a bioavailable form. Analytical data coupled with direct, visual observations of estuarine water contamination by raw phosphorites and fertilizers suggest that the major source of arsenic in the estuarine sediments originated from the fertilizer industry.

  11. WISE Catches the Lagoon Nebula in Center of Action

    NASA Image and Video Library

    2011-01-06

    This colorful picture is a mosaic of Messier 8, or the Lagoon nebula, taken by NASA Wide-field Infrared Survey Explorer. This nebula is composed of clouds of gas and dust in which new stars are forming.

  12. Mangrove soil and vegetation change after tidal wetland creation: a 20-year chronosequence in Tampa Bay, FL

    EPA Science Inventory

    Mangrove restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove loss (which has been high in recent decades: ~30-50% global loss). However, ecosystem development and functionality following mangrove restoration and creation is poorly u...

  13. Mangrove soil and vegetation change after tidal wetland creation: a 20-year chronosequence in Tampa Bay, FL

    EPA Science Inventory

    Mangrove restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove loss (which has been high in recent decades: ~30-50% global loss). However, ecosystem development and functionality following mangrove restoration and creation is poorly u...

  14. Changes in diversity of cultured bacteria resistant to erythromycin and tetracycline in swine manure during simulated composting and lagoon storage.

    PubMed

    Wang, L; Gutek, A; Grewal, S; Michel, F C; Yu, Z

    2015-09-01

    This study investigated the impact of composting and lagoon storage on survival and change in diversity of tetracycline-resistant (Tc(r) ) and erythromycin-resistant (Em(r) ) bacteria and the resistance genes they carry in swine manure. Treatments were arranged as a 2 × 2 factorial design: composting vs lagoon storage and 0 vs 1% Surround WP Crop Protectant (a clay product) in three replicates. After 48 days of treatments, resistant bacteria were enumerated by selective plating and identified by 16S rRNA gene sequencing. The erm and the tet gene(s) carried by the resistant isolates were screened using class-specific PCR assays. The plate counts of Tc(r) and Em(r) bacteria decreased by 4-7 logs by composting, but only by 1-2 logs by the lagoon treatment. During the treatments, Acinetobacter gave way to Pseudomonas and Providencia as the largest resistant genera. The clay product had little effect on survival or diversity of resistant bacteria. Of six classes of erm and seven classes of tet genes tested, changes in prevalence were also noted. The results indicate that composting can dramatically shift Tc(r) and Em(r) bacterial populations, and composting can be an effective and practical approach to decrease dissemination of antibiotic resistance from swine farms to the environment. The presented research provided evidence that composting is much more effective than lagoon storage in dramatically decreasing culturable bacteria resistant to erythromycin and tetracycline in swine manure. Considerable diversity changes of resistant bacteria were also demonstrated during composting or lagoon storage. Overall, Acinetobacter was the major resistant genus in untreated swine manure, but pseudomonads and Providencia became the major resistant genera after the treatments. This is the first study that investigated diversity changes of cultured bacteria resistant to these two antibiotics during composting and lagoon storage of swine manure. New genes encoding resistance to

  15. Impact of dredging in a shallow coastal lagoon: Microtox Basic Solid-Phase Test, trace metals and Corophium bioassay.

    PubMed

    Guerra, R; Pasteris, A; Ponti, M; Fabbri, D; Bruzzi, L

    2007-05-01

    The aim of this work was to measure survival of the amphipod Corophium insidiosum and luminescence inhibition in the marine bacterium Vibrio fisheri on surface sediment samples collected from a shallow coastal lagoon (Pialassa Baiona, northern Adriatic Italian coast) before execution of dredging operations to deepen the main inner channel of the lagoon and restore the water circulation. Trace metal (Cd, Cu, Cr, Hg, Ni, Pb) concentrations, grain size and organic carbon matter content as loss of ignition were also measured. Toxicity testing with V. fisheri was carried out according to the Microtox Basic Solid-Phase Test (BSPT) protocol. The preliminary outcomes of this work show that: (a) the investigated area can be categorised as moderately degraded; (b) there is no evident spatial pattern in sediment toxicity and trace metal concentrations; (c) Microtox responses are not biased by sediment characteristics such as silt, clay and organic matter content.

  16. Establishing a Supervised Classification of Global Blue Carbon Mangrove Ecosystems

    NASA Astrophysics Data System (ADS)

    Baltezar, P.

    2016-12-01

    Understanding change in mangroves over time will aid forest management systems working to protect them from over exploitation. Mangroves are one of the most carbon dense terrestrial ecosystems on the planet and are therefore a high priority for sustainable forest management. Although they represent 1% of terrestrial cover, they could account for about 10% of global carbon emissions. The foundation of this analysis uses remote sensing to establish a supervised classification of mangrove forests for discrete regions in the Zambezi Delta of Mozambique and the Rufiji Delta of Tanzania. Open-source mapping platforms provided a dynamic space for analyzing satellite imagery in the Google Earth Engine (GEE) coding environment. C-Band Synthetic Aperture Radar data from Sentinel 1 was used in the model as a mask by optimizing SAR parameters. Exclusion metrics identified within Global Land Surface Temperature data from MODIS and the Shuttle Radar Topography Mission were used to accentuate mangrove features. Variance was accounted for in exclusion metrics by statistically calculating thresholds for radar, thermal, and elevation data. Optical imagery from the Landsat 8 archive aided a quality mosaic in extracting the highest spectral index values most appropriate for vegetative mapping. The enhanced radar, thermal, and digital elevation imagery were then incorporated into the quality mosaic. Training sites were selected from Google Earth imagery and used in the classification with a resulting output of four mangrove cover map models for each site. The model was assessed for accuracy by observing the differences between the mangrove classification models to the reference maps. Although the model was over predicting mangroves in non-mangrove regions, it was more accurately classifying mangrove regions established by the references. Future refinements will expand the model with an objective degree of accuracy.

  17. Rehabilitation of Seven (7) Hydrocarbon Contaminated Sites in a Brackish Water/Lagoon Environment in South Trinidad

    NASA Astrophysics Data System (ADS)

    Mohammed, Avryl; Ramnath, Kelvin; Dyal, Shyam; Lalla, Francesca; Roopchand, Jaipersad

    2007-12-01

    The Petroleum Company of Trinidad and Tobago Limited operates in a wide diversity of tropical habitats in South Trinidad one of which is a brackish water environment known as the Godineau Swamp. Historically this field was operated by predecessor multinational companies, who at that time employed operational practices based on the absence of legal requirements, that were not environmentally considerate. Following a detailed environmental audit of the field (also known as the Oropouche Field), seven (7) contaminated sites were found, that presented a risk to the lagoon and its associated mangrove swamp ecology. Remediation of the seven (7) sites was done in two (2) phases; phase 1 being sampling and characterization of the waste inclusive of migration and phase 2 the actual on-site soil remediation. Phase 1 conducted during the period December 2004 to February 2005, indicated a total of 19,484 m3 of contaminated material with TPH being the main contaminant. The average concentration of TPH was 3.25%. Phase 2 remediation was initiated in October 2005 and involved the following three (3) aspects to achieve a TPH concentration of less than 1%: ▪ Preparation of waste remediation sites adjacent to contaminated sites and excavation and spreading onto cells ▪ Bioremediation onsite using naturally occurring bacteria and rototilling ▪ Rehabilitation and closure of the site following accepted lab results. The benefits of conducting this project in the petroleum industry are to ensure compliance to the national Sensitive Areas Rules and Draft Waste Management Rules, conformance to ISO 14001 Certification requirements and conservation of biodiversity in the mangrove swamp.

  18. Holocene Depositional History of Shad Pond, a Hypersaline Coastal Lagoon, Eleuthera, Bahamas and Its Influence on Lucayan Occupation

    NASA Astrophysics Data System (ADS)

    Boush, L. E.; Fentress, S.; Conroy, M.; Cook, A.; Miseridina, D.; Buynevich, I. V.; Myrbo, A.; Brown, E. T.; Berman, M.; Gnivecki, P.; Kjellmark, E.; Savarese, M.; Brady, K.

    2013-12-01

    Shad Pond, an enclosed hypersaline lagoon on the southeastern tip of Eleuthera, Bahamas reveals a ~5000-year record of hurricane activity, as well as sea-level and climate change history. Three sediment cores recovered 1.04-2.54 m of sediment over bedrock along a transect perpendicular to shoreline. Sediment composition and grain size, loss on ignition, X-ray fluorescence (XRF) measurements of the cores along with dune transects and ground-penetrating radar (GPR) profiles adjacent to the lake provide a comprehensive dataset to interpret the history of this coastal basin. The sedimentary sequence was composed of alternating lithofacies that included microbial mats, sand, and peat. Laminated mats often alternated with sandy layers in thin to medium-bedded units. Two peat layers were found in the basal part of the shore-distal core (Site 1) between 1.82-2.40 m and 2.53-2.54 m and were separated by a 13-cm-thick gray mud layer. In general, organic matter and carbonate content tracked granulometry and composition in all cores. High-resolution XRF scans of Ca and Sr at Site 1 show elevated levels ~3,700 cal yBP, which correlate with the top of the peat layer, but these elemental concentrations vary at Site 3. XRF measurements of Fe indicate a dust flux that has been recorded regionally throughout the Caribbean. Dune transects and GPR profiles indicate a phased history of the pond, beginning with initial stages as an open lagoon dominated by red mangrove, with black mangrove and buttonwood also present. The lake likely closed at approximately 3,700 cal yBP indicated by the transition between the upper peat and microbial mat layers. This could have been due to increased storm events in a regime of rising sea level. Aeolian aggradation continued to heighten the barrier between the bedrock headlands to its present position. Hurricane overwash deposits punctuated the algal mat accumulation throughout this time period. Present-day hypersaline conditions sustain algal mats

  19. Methane emissions from dairy lagoons in the western United States.

    PubMed

    Leytem, A B; Bjorneberg, D L; Koehn, A C; Moraes, L E; Kebreab, E; Dungan, R S

    2017-08-01

    Methane generation from dairy liquid storage systems is a major source of agricultural greenhouse gas emissions. However, little on-farm research has been conducted to estimate and determine the factors that may affect these emissions. Six lagoons in south-central Idaho were monitored for 1 yr, with CH4 emissions estimated by inverse dispersion modeling. Lagoon characteristics thought to contribute to CH4 emissions were also monitored over this time period. Average emissions from the lagoons ranged from 30 to 126 kg/ha per day or 22 to 517 kg/d. Whereas we found a general trend for greater emissions during the summer, when temperatures were greater, events such as pumping, rainfall, freeze or thaw of lagoon surfaces, and wind significantly increased CH4 emissions irrespective of temperature. Lagoon physicochemical characteristics, such as total solids, chemical oxygen demand, and volatile solids, were highly correlated with emission. Methane prediction models were developed using volatile solids, wind speed, air temperature, and pH as independent variables. The US Environmental Protection Agency methodology for estimating CH4 emissions from manure storage was used for comparison of on-farm CH4 emissions from 1 of the lagoon systems. The US Environmental Protection Agency method underestimated CH4 emissions by 48%. An alternative methodology, using volatile solids degradation factor, provided a more accurate estimate of annual emissions from the lagoon system and may hold promise for applicability across a range of dairy lagoon systems in the United States. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

  20. Accumulation, Characterization, and Stabilization of Sludges for Cold Regions Lagoons

    DTIC Science & Technology

    1984-04-01

    aide If necesary and Identify by block number) Cold regions Lagoons Sanitary engineering Sewage Sludge 20 ASTIACT’ (CVtha sm etam aM N rnemind i...regions sludge accumulates during cold winter months but digests sufficiently during the warmer summer months to maintain the desired balance ...benthic sludge accumulation zone for only 2 to 4 months per year. If excess sludge in sewage lagoons is accumulating, then sludge volume and

  1. Avicennia germinans (black mangrove) vessel architecture is linked to chilling and salinity tolerance in the Gulf of Mexico.

    PubMed

    Madrid, Eric N; Armitage, Anna R; López-Portillo, Jorge

    2014-01-01

    Over the last several decades, the distribution of the black mangrove Avicennia germinans in the Gulf of Mexico has expanded, in part because it can survive the occasional freeze events and high soil salinities characteristic of the area. Vessel architecture may influence mangrove chilling and salinity tolerance. We surveyed populations of A. germinans throughout the Gulf to determine if vessel architecture was linked to field environmental conditions. We measured vessel density, hydraulically weighted vessel diameter, potential conductance capacity, and maximum tensile fracture stress. At each sampling site we recorded mangrove canopy height and soil salinity, and determined average minimum winter temperature from archived weather records. At a subset of sites, we measured carbon fixation rates using a LI-COR 6400XT Portable Photosynthesis System. Populations of A. germinans from cooler areas (Texas and Louisiana) had narrower vessels, likely reducing the risk of freeze-induced embolisms but also decreasing water conductance capacity. Vessels were also narrower in regions with high soil salinity, including Texas, USA and tidal flats in Veracruz, Mexico. Vessel density did not consistently vary with temperature or soil salinity. In abiotically stressful areas, A. germinans had a safe hydraulic architecture with narrower vessels that may increase local survival. This safe architecture appears to come at a substantial physiological cost in terms of reduction in conductance capacity and carbon fixation potential, likely contributing to lower canopy heights. The current distribution of A. germinans in the Gulf is influenced by the complex interplay between temperature, salinity, and vessel architecture. Given the plasticity of A. germinans vessel characters, it is likely that this mangrove species will be able to adapt to a wide range of potential future environmental conditions, and continue its expansion in the Gulf of Mexico in response to near-term climate change.

  2. Avicennia germinans (black mangrove) vessel architecture is linked to chilling and salinity tolerance in the Gulf of Mexico

    PubMed Central

    Madrid, Eric N.; Armitage, Anna R.; López-Portillo, Jorge

    2014-01-01

    Over the last several decades, the distribution of the black mangrove Avicennia germinans in the Gulf of Mexico has expanded, in part because it can survive the occasional freeze events and high soil salinities characteristic of the area. Vessel architecture may influence mangrove chilling and salinity tolerance. We surveyed populations of A. germinans throughout the Gulf to determine if vessel architecture was linked to field environmental conditions. We measured vessel density, hydraulically weighted vessel diameter, potential conductance capacity, and maximum tensile fracture stress. At each sampling site we recorded mangrove canopy height and soil salinity, and determined average minimum winter temperature from archived weather records. At a subset of sites, we measured carbon fixation rates using a LI-COR 6400XT Portable Photosynthesis System. Populations of A. germinans from cooler areas (Texas and Louisiana) had narrower vessels, likely reducing the risk of freeze-induced embolisms but also decreasing water conductance capacity. Vessels were also narrower in regions with high soil salinity, including Texas, USA and tidal flats in Veracruz, Mexico. Vessel density did not consistently vary with temperature or soil salinity. In abiotically stressful areas, A. germinans had a safe hydraulic architecture with narrower vessels that may increase local survival. This safe architecture appears to come at a substantial physiological cost in terms of reduction in conductance capacity and carbon fixation potential, likely contributing to lower canopy heights. The current distribution of A. germinans in the Gulf is influenced by the complex interplay between temperature, salinity, and vessel architecture. Given the plasticity of A. germinans vessel characters, it is likely that this mangrove species will be able to adapt to a wide range of potential future environmental conditions, and continue its expansion in the Gulf of Mexico in response to near-term climate change

  3. Masterplan to safeguard Venice and to restore the lagoon and conterminous areas

    NASA Astrophysics Data System (ADS)

    Bini, Claudio; Gallo, Alba; Nadimi-Goki, Mandana; Wahsha, Mohammad

    2015-04-01

    ). PAH and metals, in particular, present wide diffusion, both horizontal and vertical (until 5 m below the sea level), with As, Zn, Cd and Hg being the elements more represented in all the soil strata considered. The lagoon sediments inside industrial channels is higher than the other parts of the lagoon; major contaminants are metals (As, Cd, Hg, Pb) and organic micro-pollutants (PCB, PAH); ammonia and phosphate too are present with conspicuous concentrations, contributing to lagoon eutrophication. Groundwater contamination is diffused and complex, with As prevailing over Pb and Cr(VI). The primary objective of the Master Plan was to reduce/eliminate the risk associated to the contamination sources of past activities, and the consequent environmental and human health hazard. Restoration is still in progress, and concerns different intervention strategies: • Channel overbank containment to prevent contaminant migration to water; • Excavation, physical removal and re-distribution of channel sediments (A and B classes); • Landfilling of heavily contaminated sediments (C class); • Soil containment to impede contact with people and the environment; • Restoration of contaminated agricultural land with phytoremediation techniques. Concerning in particular the last item, restoration has been carried out with native or exotic vegetation (e.g. Fragmites australis, Juncus lacustris, Pterix vittata, Spartina maritima), or cultivated plants (e.g. Heliantus annuus, Zea mays, Brassica napus), with contrasting results. The exotic fern (Pterix vittata) proved highly effective to accumulate As, consistently with data from literature; Spartina maritima proved more effective than Fragmites australis to uptake metals, while cultivated plants could not survive to high heavy metal concentrations. At some sites, soil has been stored, selected and finally (the most contaminated part) delivered to landfill, while groundwater was remediated by bioremediation techniques.

  4. Mangrove species' responses to winter air temperature extremes in China

    USGS Publications Warehouse

    Chen, Luzhen; Wang, Wenqing; Li, Qingshun Q.; Zhang, Yihui; Yang, Shengchang; Osland, Michael J.; Huang, Jinliang; Peng, Congjiao

    2017-01-01

    The global distribution and diversity of mangrove forests is greatly influenced by the frequency and intensity of winter air temperature extremes. However, our understanding of how different mangrove species respond to winter temperature extremes has been lacking because extreme freezing and chilling events are, by definition, relatively uncommon and also difficult to replicate experimentally. In this study, we investigated species-specific variation in mangrove responses to winter temperature extremes in China. In 10 sites that span a latitudinal gradient, we quantified species-specific damage and recovery following a chilling event, for mangrove species within and outside of their natural range (i.e., native and non-native species, respectively). To characterize plant stress, we measured tree defoliation and chlorophyll fluorescence approximately one month following the chilling event. To quantify recovery, we measured chlorophyll fluorescence approximately nine months after the chilling event. Our results show high variation in the geographic- and species-specific responses of mangroves to winter temperature extremes. While many species were sensitive to the chilling temperatures (e.g., Bruguiera sexangula and species in the Sonneratia and Rhizophora genera), the temperatures during this event were not cold enough to affect certain species (e.g., Kandelia obovata, Aegiceras corniculatum, Avicennia marina, and Bruguiera gymnorrhiza). As expected, non-native species were less tolerant of winter temperature extremes than native species. Interestingly, tidal inundation modulated the effects of chilling. In comparison with other temperature-controlled mangrove range limits across the world, the mangrove range limit in China is unique due to the combination of the following three factors: (1) Mangrove species diversity is comparatively high; (2) winter air temperature extremes, rather than means, are particularly intense and play an important ecological

  5. Tidal dynamics in a frictionally dominated tropical lagoon

    NASA Astrophysics Data System (ADS)

    Tenorio-Fernandez, L.; Gomez-Valdes, J.; Marino-Tapia, I.; Enriquez, C.; Valle-Levinson, A.; Parra, S. M.

    2016-02-01

    This study examined the dynamics of tidal propagation inside a tropical lagoon. Sea surface elevation (inside) and current profiles (at the inlet) were examined over 60 days at the Chelem lagoon, which is a branched tropical lagoon located in the northern Yucatan Peninsula. Tides were predominantly diurnal with a wavelength at least 20 times longer than the total length of the basin. Spatial variations of sea surface elevation and the longitudinal transport were described in each branch by applying a linear analytical model and the results were compared to observations. Results showed that the coastal lagoon was highly frictional. The tidal signal was attenuated between 30% and 40% toward the lagoon heads, a result of the balance between pressure gradient and frictional forces. A causeway that chokes the western side of the lagoon allowed the propagation of the diurnal signal toward the west head of the basin but damped the semidiurnal signal. The causeway acted as a hydraulic low-pass filter, as in natural choked systems. The causeway's filter effect was included in the analytical model by optimizing the frictional parameters.

  6. Trophic characteristics of a mangrove fish community in Southwest Thailand: Important mangrove contribution and intraspecies feeding variability

    NASA Astrophysics Data System (ADS)

    Zagars, Matiss; Ikejima, Kou; Kasai, Akihide; Arai, Nobuaki; Tongnunui, Prasert

    2013-03-01

    Mangrove production has been found to make a major contribution to the nutrition of a fish community in the Sikao Creek mangrove estuary, Southwest Thailand. Gut content analysis and carbon and nitrogen stable isotope analysis were used to assess fish feeding behavior and trophic reliance on different primary producers (mangrove leaves, phytoplankton, microphytobenthos) focusing on 19 dominant fish species, and 4 potential fish food items. Cluster analysis identified 5 trophic groups and the IsoSource model indicated the importance of primary food sources in trophically supporting different fish species. Most analyzed fish species had carbon isotopic signatures that were more depleted than those reported in previous studies, and the IsoSource model indicated that mangrove leaves were an important primary food source. This may be a specific characteristic of our study site, which is not well connected to other productive coastal habitats that provide alternative primary food sources. Thus we suggest that food chains in trophically isolated mangrove estuaries of southwest Thailand are more dependent on mangrove tree production. We also assessed the relationship of individuality in fish feeding habits and variability of δ13C values and showed that several mangrove fish species have significant intraspecies variability in feeding habits, possibly due to high intraspecific competition.

  7. Pathways of priority pesticides in sediments of coastal lagoons: The case study of Óbidos Lagoon, Portugal.

    PubMed

    Pinto, M I; Vale, C; Sontag, G; Noronha, J P

    2016-05-15

    This study reports the concentrations of the priority pesticides (PPs) in 14 surface sediments and 21 layers of a sediment core from Óbidos Lagoon, a shallow Portuguese coastal lagoon. Results show that the PPs are confined to the upper part of the lagoon that receives most of the inputs from surface runoff of the surrounding agricultural fields and from small tributaries. Past and recent applied PPs were registered in sediments, aluminum normalized concentrations varying between 0.05×10(-7) and 6.85×10(-7). The PP risk assessment based on sediment quality guidelines like the "Probable Effect Level" (PEL) shows no biological effects in either sediments or aquatic organisms of Óbidos Lagoon, except for dieldrin, lindane, DDT, heptachlor epoxide and its parent compound heptachlor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Spatial and temporal extension of eutrophication associated with shrimp farm wastewater discharges in the New Caledonia lagoon.

    PubMed

    Thomas, Yoann; Courties, Claude; El Helwe, Yasmin; Herbland, Alain; Lemonnier, Hugues

    2010-01-01

    Shrimp farming in New Caledonia typically uses a flow-through system with water exchange rates as a tool to maintain optimum hydrological and biological parameters for the crop. Moreover, the effluent shows hydrobiological characteristics (minerals, phytoplankton biomass and organic matter) significantly higher than that of the receiving environment. Separate surveys were carried out in a bay (CH Bay) with a medium-size intensive farm (30 ha) (PO) and in a mangrove-lined creek (TE Creek) near a larger semi-intensive farm (133 ha) (SO). Net loads of nitrogen exported from the semi-intensive farm and the intensive farm amounted to 0.68 and 1.36 kg ha(-1)day(-1), respectively. At CH Bay, discharge effects were spatially limited and clearly restricted to periods of effluent release. The high residence time at site TE favoured the installation of a feedback system in which organic matter was not exported. Mineralization of organic matter led to the release of nutrients, which in turn, caused in an increased eutrophication of this ecosystem. The study of the pico- and nanophytoplankton assemblages showed (i) a shift in composition from picophytoplankton to nanophytoplankton from offshore towards the coast and (ii) a shift within the picophytoplankton with the disappearance of Prochlorococcus and the increase of picoeucaryotes towards the shoreline. These community changes may partially be related to a nitrogen enrichment of the environment by shrimp farm discharges. Thus, in view of the recent addition of the New Caledonian lagoon to the UNESCO World Heritage list, the data presented here could be a first approach to quantify farm discharges and evaluate their impact on the lagoon.

  9. Levels of platinum group metals in selected species (Sarotherodon melanotheron, Chonophorus lateristriga, Macrobrachium vollenhovenii and Crassostrea tulipa) in some estuaries and lagoons along the coast of Ghana.

    PubMed

    Essumang, D K; Adokoh, C K; Boamponsem, L

    2010-10-12

    The use of some biota as bioindicators of heavy metal pollution has been demonstrated as particularly adequate due to their capacity of bioconcentration. This study evaluated the levels of platinum group metals (PGMs) in some selected species along the coastal belt of Ghana, using the neutron activation analysis (NAA) method. The result was processed to evaluate pollution indices in order to map the distribution of the metals in those species in the lagoons and estuaries along the costal belt of Ghana. The analysis showed significant levels of all PGMs in blackchin tilapia (Sarotherodon melanotheron Cichlidae), brown goby (Chonophorus lateristriga Gobiidae), shrimp (Macrobrachium vollenhovenii Palaemonidae), and mangrove oysters (Crassostrea tulipa Ostreidae) in the lagoons and river Pra estuary. However, the oysters showed an elevated mean concentration of 0.13 μg/g (dry weight) Pd. From the pollution indices, most of the sampling sites registered mean contamination factor (CF) values between 1.20 and 3.00 for Pt, Pd, and Rh. The pollution load index (PLI) conducted also gave an average pollution index between 0.79 and 2.37, indicating progressive contamination levels. The results revealed that anthropogenic sources, industrial and hospital effluent, etc., together with vehicular emissions, could be the contributing factors to the deposition of PGMs along the Ghanaian coast.

  10. Competition between hardwood hammocks and mangroves

    USGS Publications Warehouse

    Sternberg, L.D.S.L.; Teh, S.Y.; Ewe, S.M.L.; Miralles-Wilhelm, F.; DeAngelis, D.L.

    2007-01-01

    The boundaries between mangroves and freshwater hammocks in coastal ecotones of South Florida are sharp. Further, previous studies indicate that there is a discontinuity in plant predawn water potentials, with woody plants either showing predawn water potentials reflecting exposure to saline water or exposure to freshwater. This abrupt concurrent change in community type and plant water status suggests that there might be feedback dynamics between vegetation and salinity. A model examining the salinity of the aerated zone of soil overlying a saline body of water, known as the vadose layer, as a function of precipitation, evaporation and plant water uptake is presented here. The model predicts that mixtures of saline and freshwater vegetative species represent unstable states. Depending on the initial vegetation composition, subsequent vegetative change will lead either to patches of mangrove coverage having a high salinity vadose zone or to freshwater hammock coverage having a low salinity vadose zone. Complete or nearly complete coverage by either freshwater or saltwater vegetation represents two stable steady-state points. This model can explain many of the previous observations of vegetation patterns in coastal South Florida as well as observations on the dynamics of vegetation shifts caused by sea level rise and climate change. ?? 2007 Springer Science+Business Media, LLC.

  11. Mosquitoes of the mangrove forests of India: part 7--an overview.

    PubMed

    Rajavel, A R; Natarajan, R

    2008-12-01

    Parts 1 to 6 of this series on the mosquitoes of the mangrove forests of India dealt with the mosquito species recorded in the mangroves of Bhitarkanika, Sundarbans, Andaman and Nicobar islands, Coringa, Chorao and Vikhroli, and Kundapur and Kannur. This concluding part provides an overview of the distribution of the mosquito species in different mangrove forests, including the mangroves of Muthupet in Tamilnadu and the mangroves of Gulf of Kutch and Gulf of Kambhat in Gujarat, species collected as larvae, species in relation to the salinity of the larval habitats, species landing on humans for feeding in the mangroves, and the impact of habitat degradation on species diversity.

  12. Distribution and dynamics of mangrove forests of South Asia.

    PubMed

    Giri, Chandra; Long, Jordan; Abbas, Sawaid; Murali, R Mani; Qamer, Faisal M; Pengra, Bruce; Thau, David

    2015-01-15

    Mangrove forests in South Asia occur along the tidal sea edge of Bangladesh, India, Pakistan, and Sri Lanka. These forests provide important ecosystem goods and services to the region's dense coastal populations and support important functions of the biosphere. Mangroves are under threat from both natural and anthropogenic stressors; however the current status and dynamics of the region's mangroves are poorly understood. We mapped the current extent of mangrove forests in South Asia and identified mangrove forest cover change (gain and loss) from 2000 to 2012 using Landsat satellite data. We also conducted three case studies in Indus Delta (Pakistan), Goa (India), and Sundarbans (Bangladesh and India) to identify rates, patterns, and causes of change in greater spatial and thematic details compared to regional assessment of mangrove forests. Our findings revealed that the areal extent of mangrove forests in South Asia is approximately 1,187,476 ha representing ∼7% of the global total. Our results showed that from 2000 to 2012, 92,135 ha of mangroves were deforested and 80,461 ha were reforested with a net loss of 11,673 ha. In all three case studies, mangrove areas have remained the same or increased slightly, however, the turnover was greater than the net change. Both, natural and anthropogenic factors are responsible for the change and turnover. The major causes of forest cover change are similar throughout the region; however, specific factors may be dominant in specific areas. Major causes of deforestation in South Asia include (i) conversion to other land use (e.g. conversion to agriculture, shrimp farms, development, and human settlement), (ii) over-harvesting (e.g. grazing, browsing and lopping, and fishing), (iii) pollution, (iv) decline in freshwater availability, (v) floodings, (vi) reduction of silt deposition, (vii) coastal erosion, and (viii) disturbances from tropical cyclones and tsunamis. Our analysis in the region's diverse socio-economic and

  13. Pristine mangrove creek waters are a sink of nitrous oxide

    NASA Astrophysics Data System (ADS)

    Maher, Damien T.; Sippo, James Z.; Tait, Douglas R.; Holloway, Ceylena; Santos, Isaac R.

    2016-05-01

    Nitrous oxide (N2O) is an important greenhouse gas, but large uncertainties remain in global budgets. Mangroves are thought to be a source of N2O to the atmosphere in spite of the limited available data. Here we report high resolution time series observations in pristine Australian mangroves along a broad latitudinal gradient to assess the potential role of mangroves in global N2O budgets. Surprisingly, five out of six creeks were under-saturated in dissolved N2O, demonstrating mangrove creek waters were a sink for atmospheric N2O. Air-water flux estimates showed an uptake of 1.52 ± 0.17 μmol m‑2 d‑1, while an independent mass balance revealed an average sink of 1.05 ± 0.59 μmol m‑2 d‑1. If these results can be upscaled to the global mangrove area, the N2O sink (~2.0 × 108 mol yr‑1) would offset ~6% of the estimated global riverine N2O source. Our observations contrast previous estimates based on soil fluxes or mangrove waters influenced by upstream freshwater inputs. We suggest that the lack of available nitrogen in pristine mangroves favours N2O consumption. Widespread and growing coastal eutrophication may change mangrove waters from a sink to a source of N2O to the atmosphere, representing a positive feedback to climate change.

  14. Prioritising Mangrove Ecosystem Services Results in Spatially Variable Management Priorities.

    PubMed

    Atkinson, Scott C; Jupiter, Stacy D; Adams, Vanessa M; Ingram, J Carter; Narayan, Siddharth; Klein, Carissa J; Possingham, Hugh P

    2016-01-01

    Incorporating the values of the services that ecosystems provide into decision making is becoming increasingly common in nature conservation and resource management policies, both locally and globally. Yet with limited funds for conservation of threatened species and ecosystems there is a desire to identify priority areas where investment efficiently conserves multiple ecosystem services. We mapped four mangrove ecosystems services (coastal protection, fisheries, biodiversity, and carbon storage) across Fiji. Using a cost-effectiveness analysis, we prioritised mangrove areas for each service, where the effectiveness was a function of the benefits provided to the local communities, and the costs were associated with restricting specific uses of mangroves. We demonstrate that, although priority mangrove areas (top 20%) for each service can be managed at relatively low opportunity costs (ranging from 4.5 to 11.3% of overall opportunity costs), prioritising for a single service yields relatively low co-benefits due to limited geographical overlap with priority areas for other services. None-the-less, prioritisation of mangrove areas provides greater overlap of benefits than if sites were selected randomly for most ecosystem services. We discuss deficiencies in the mapping of ecosystems services in data poor regions and how this may impact upon the equity of managing mangroves for particular services across the urban-rural divide in developing countries. Finally we discuss how our maps may aid decision-makers to direct funding for mangrove management from various sources to localities that best meet funding objectives, as well as how this knowledge can aid in creating a national mangrove zoning scheme.

  15. Prioritising Mangrove Ecosystem Services Results in Spatially Variable Management Priorities

    PubMed Central

    Atkinson, Scott C.; Jupiter, Stacy D.; Adams, Vanessa M.; Ingram, J. Carter; Narayan, Siddharth; Klein, Carissa J.; Possingham, Hugh P.

    2016-01-01

    Incorporating the values of the services that ecosystems provide into decision making is becoming increasingly common in nature conservation and resource management policies, both locally and globally. Yet with limited funds for conservation of threatened species and ecosystems there is a desire to identify priority areas where investment efficiently conserves multiple ecosystem services. We mapped four mangrove ecosystems services (coastal protection, fisheries, biodiversity, and carbon storage) across Fiji. Using a cost-effectiveness analysis, we prioritised mangrove areas for each service, where the effectiveness was a function of the benefits provided to the local communities, and the costs were associated with restricting specific uses of mangroves. We demonstrate that, although priority mangrove areas (top 20%) for each service can be managed at relatively low opportunity costs (ranging from 4.5 to 11.3% of overall opportunity costs), prioritising for a single service yields relatively low co-benefits due to limited geographical overlap with priority areas for other services. None-the-less, prioritisation of mangrove areas provides greater overlap of benefits than if sites were selected randomly for most ecosystem services. We discuss deficiencies in the mapping of ecosystems services in data poor regions and how this may impact upon the equity of managing mangroves for particular services across the urban-rural divide in developing countries. Finally we discuss how our maps may aid decision-makers to direct funding for mangrove management from various sources to localities that best meet funding objectives, as well as how this knowledge can aid in creating a national mangrove zoning scheme. PMID:27008421

  16. Could mangroves be Tampa Bay's next cash crop?

    USGS Publications Warehouse

    Cimitile, Matthew

    2008-01-01

    Obviously, no one is recommending cutting down mangroves to sell, but environmental managers are working toward putting a price tag on the benefits they provide to help ensure that they are protected. Though the process is just beginning here, estimates from studies in other locations indicate that the 15,000 acres of mangrove forests surrounding Tampa Bay could be worth $75 to $225 million a year for the services they provide.

  17. Mangrove forest recovery in the Everglades following Hurricane Wilma

    USGS Publications Warehouse

    Sarmiento, Daniel; Barr, Jordan; Engel, Vic; Fuentes, Jose D.; Smith, Thomas J.; Zieman, Jay C.

    2009-01-01

    On October 24th, 2005, Hurricane Wilma made landfall on the south western shore of the Florida peninsula. This major disturbance destroyed approximately 30 percent of the mangrove forests in the area. However, the damage to the ecosystem following the hurricane provided researchers at the Florida Coastal Everglades (FCE) LTER site with the rare opportunity to track the recovery process of the mangroves as determined by carbon dioxide (CO2) and energy exchanges, measured along daily and seasonal time scales.

  18. Pristine mangrove creek waters are a sink of nitrous oxide

    PubMed Central

    Maher, Damien T.; Sippo, James Z.; Tait, Douglas R.; Holloway, Ceylena; Santos, Isaac R.

    2016-01-01

    Nitrous oxide (N2O) is an important greenhouse gas, but large uncertainties remain in global budgets. Mangroves are thought to be a source of N2O to the atmosphere in spite of the limited available data. Here we report high resolution time series observations in pristine Australian mangroves along a broad latitudinal gradient to assess the potential role of mangroves in global N2O budgets. Surprisingly, five out of six creeks were under-saturated in dissolved N2O, demonstrating mangrove creek waters were a sink for atmospheric N2O. Air-water flux estimates showed an uptake of 1.52 ± 0.17 μmol m−2 d−1, while an independent mass balance revealed an average sink of 1.05 ± 0.59 μmol m−2 d−1. If these results can be upscaled to the global mangrove area, the N2O sink (~2.0 × 108 mol yr−1) would offset ~6% of the estimated global riverine N2O source. Our observations contrast previous estimates based on soil fluxes or mangrove waters influenced by upstream freshwater inputs. We suggest that the lack of available nitrogen in pristine mangroves favours N2O consumption. Widespread and growing coastal eutrophication may change mangrove waters from a sink to a source of N2O to the atmosphere, representing a positive feedback to climate change. PMID:27172603

  19. Dissolved iron supply limits early growth of estuarine mangroves.

    PubMed

    Alongi, Daniel M

    2010-11-01

    Three mesocosm experiments were performed in an outdoor facility to quantify the responses of five mangrove species grown from seedling to sapling stage to increasing rates of dissolved iron supply. Stem extension and biomass of mangroves were measured in the first two experiments, and in the third experiment, rates of microbial iron reduction were measured in relation to stem extension of two mangrove species. In all experiments, mangrove growth was enhanced by increasing iron supply, although some species showed iron toxicity at the higher supply rates. In the first two experiments, stem extension rates of Rhizophora apiculata, Bruguiera gymnorrhiza, and Xylocarpus moluccensis best fit Gaussian curves with maximal growth at supply rates of 50-60 mmol Fe x m(-2) x d(-1), whereas growth of Avicennia marina and Ceriops tagal increased to the highest rate (100 mmol Fe x m(-2) x d(-1)) of iron supply. Changes in leaf chlorophyll concentrations and iron content of roots mirrored the growth responses. In the third experiment, rates of microbial iron reduction were greater with R. apiculata and A. marina than in controls without plants; for both species, there was a positive relationship between stem extension and iron reduction. The rates of iron reduction and rates of iron supplied to the plants were well within the range of interstitial iron concentrations and rates of iron reduction found in the natural mangrove soils from which the seedlings were obtained. The responses of these species show that mangroves growing from seedling to sapling stage have a strong nutritional requirement for iron, and that there is a close relationship between plant roots and the activities of iron-reducing bacteria. These results suggest that mangrove growth may be limited in some natural forests by the rate at which iron is solubilized by iron-reducing bacteria. Such biogeochemical conditions have significant implications for successful recruitment, establishment, and early growth of

  20. Dynamic control of osmolality and ionic composition of the xylem sap in two mangrove species.

    PubMed

    López-Portillo, Jorge; Ewers, Frank W; Méndez-Alonzo, Rodrigo; Paredes López, Claudia L; Angeles, Guillermo; Alarcón Jiménez, Ana Luisa; Lara-Domínguez, Ana Laura; Torres Barrera, María Del Carmen

    2014-06-01

    • Premise of the study: Xylem sap osmolality and salinity is a critical unresolved issue in plant function with impacts on transport efficiency, pressure gradients, and living cell turgor pressure, especially for halophytes such as mangrove trees.• Methods: We collected successive xylem vessel sap samples from stems and shoots of Avicennia germinans and Laguncularia racemosa using vacuum and pressure extraction and measured their osmolality. Following a series of extractions with the pressure chamber, we depressurized the shoot and pressurized again after various equilibration periods (minutes to hours) to test for dynamic control of osmolality. Transpiration and final sap osmolality were measured in shoots perfused with deionized water or different seawater dilutions.• Key results: For both species, the sap osmolality values of consecutive samples collected by vacuum extraction were stable and matched those of the initial samples extracted with the pressure chamber. Further extraction of samples with the pressure chamber decreased sap osmolality, suggesting reverse osmosis occurred. However, sap osmolalities increased when longer equilibration periods after sap extraction were allowed. Analysis of expressed sap with HPLC indicated a 1:1 relation between measured osmolality and the osmolality of the inorganic ions in the sap (mainly Na(+), K(+), and Cl(-)), suggesting no contamination by organic compounds. In stems perfused with deionized water, the sap osmolality increased to mimic the native sap osmolality.• Conclusions: Xylem sap osmolality and ionic contents are dynamically adjusted by mangroves and may help modulate turgor pressure, hydraulic conductivity, and water potential, thus being important for mangrove physiology, survival, and distribution.

  1. Selection of an omnivorous diet by the mangrove tree crab Aratus pisonii in laboratory experiments

    NASA Astrophysics Data System (ADS)

    Erickson, Amy A.; Feller, Ilka C.; Paul, Valerie J.; Kwiatkowski, Lisa M.; Lee, Woody

    2008-02-01

    Observational studies on leaf damage, gut content analyses, and crab behaviour have demonstrated that like numerous other mangrove and salt-marsh generalists, the mangrove tree crab Aratus pisonii feeds on a variety of food resources. This study is the first that experimentally tests feeding preferences of A. pisonii, as well as the first to test experimentally whether chemical composition of food resources is responsible for food selection. Feeding preferences were determined among a variety of plant, algal, and animal resources available in the field both in Florida and Belize, using multiple-choice feeding assays, where male and female crabs simultaneously were offered a variety of food items. To test whether chemistry of food resources was responsible for feeding preferences, chemical extracts of food resources were incorporated in an agar-based artificial food, and used in feeding assays. Results of feeding assays suggest that crabs prefer animal matter from ˜ 2.5 to 13× more than other available resources, including leaves of the red mangrove Rhizophora mangle, which contribute the most to their natural diet. Artificial feeding assays also demonstrated that chemical cues were responsible for selection of animal matter, up to 25× more than other available resources. Non-polar extracts (derived from extraction in 1:1 ethyl actetate:methanol) stimulated feeding the most, suggesting that fatty acids, triglycerides, or sterols may be important for growth, reproduction, or survival. Results for both sexes were similar across most assays. While chemical composition of food resources appears to play some role in selection, this does not discount the potential role of other factors, such as resource availability, competition, predation, or reproductive requirements in influencing feeding preferences. Bioassay-guided fractionation of extracts should aid in determining chemical constituents that play the greatest role in determining feeding preferences.

  2. Mudwhelks and mangroves: the evolutionary history of an ecological association (Gastropoda: Potamididae).

    PubMed

    Reid, D G; Dyal, P; Lozouet, P; Glaubrecht, M; Williams, S T

    2008-05-01

    Most of the 29 living species of Potamididae show a close association with mangroves. The trees provide the snails with shelter, protection from predators, a solid substrate and sometimes food. Using sequences from three genes (nuclear 18S rRNA and 28S rRNA, mitochondrial COI) we derive a molecular phylogeny and recognize six living genera (Terebralia, Telescopium, Tympanotonos, Cerithidea, Cerithideopsis, Cerithideopsilla). The oldest modern genera (Terebralia, Cerithideopsis) appeared in the Tethyan realm in the Middle Eocene, shortly after the origin of mangrove trees. Whereas most potamidid genera are now restricted to either the Indo-West Pacific (IWP) or to the eastern Pacific plus Atlantic (EPA), sister clades of Cerithideopsis survive in both realms. Based on a reinterpretation of the fossil record (particularly of the monotypic Tympanotonos and extinct Potamides), and parsimonious reconstruction of ancestral habitats, we suggest that the living potamidids are an adaptive radiation that has always been closely associated with mangroves. The specialized tree-climbing groups Cerithidea and Cerithideopsis were independently derived from mud-dwelling ancestors. Cerithideopsilla cingulata (a species complex in the IWP) and 'Potamides' conicus (in the Mediterranean and Indian Ocean) form a single clade within the genus Cerithideopsilla. This refutes the hypothesis that 'P.'conicus is the sole relict of the Tethyan Potamides that has occurred in the Mediterranean region since the Palaeocene. Instead, the phylogeny and fossil record suggest that an ancestor of Cerithideopsilla conica with planktotrophic larvae dispersed from the IWP to the Mediterranean in the Middle Miocene, that its direct development evolved in the Mediterranean during the Pliocene, and that it reinvaded the Indian Ocean during the Plio-Pleistocene.

  3. Cross-shore gradients of physical disturbance in mangroves: implications for seedling establishment

    NASA Astrophysics Data System (ADS)

    Balke, T.; Bouma, T. J.; Herman, P. M. J.; Horstman, E. M.; Sudtongkong, C.; Webb, E. L.

    2013-08-01

    Mangroves may grow in an active sedimentary environment and are therefore closely linked to physical coastal processes. Seedlings colonize dynamic tidal flats, after which mangroves have the potential to change their physical environment by attenuating hydrodynamic energy and trapping sediments. Disturbance from hydrodynamic energy of waves or currents and the resulting sediment dynamics appear to be a critical bottleneck for seedling establishment on tidal flats and at the forest fringe. However, knowledge about the mechanisms at the single plant level and the spatial pattern of disturbance is limited. By means of a flume study, we demonstrate that a surface erosion threshold of as little as 1-3 cm depth can lead to failure of young seedlings. By monitoring accretion/erosion for 8 months along cross-shore transects in southwest Thailand, we show that, especially on the bare mudflat, the physical sediment disturbance regularly exceeds the critical erosion thresholds derived from the flume study. Physical sediment parameters along the same transects were analysed to deduct patterns of hydrodynamic energy attenuation. Grain size analysis and erosion/accretion data showed only limited energy dissipation within the fringing Avicennia/Sonneratia zone; sediment dynamics only dropped below lethal values for seedlings within the denser Rhizophora zone. Overall, present results emphasize that (i) seedling survival is extremely sensitive to physically driven sediment dynamics and (ii) that such physical disturbances are not only present on the tidal flats but can penetrate a significant distance into the forest. Spatio-temporal patterns in sediment dynamics should hence be considered when conducting restoration of mangrove ecosystems.

  4. Cross-shore gradients of physical disturbance in mangroves: implications for seedling establishment

    NASA Astrophysics Data System (ADS)

    Balke, T.; Bouma, T. J.; Herman, P. M. J.; Horstman, E. M.; Sudtongkong, C.; Webb, E. L.

    2013-03-01

    Mangroves grow in an active sedimentary environment and are therefore closely linked to physical coastal processes. Seedlings colonize dynamic tidal flats, after which mangroves have the potential to change their physical environment by attenuating hydrodynamic energy and trapping sediments. Disturbance from hydrodynamic energy of waves or currents and the resulting sediment dynamics appear to be a critical bottleneck for seedling establishment on tidal flats and at the forest fringe. However, knowledge about the mechanisms at the single plant level and the spatial pattern of disturbance is limited. By means of a flume study, we demonstrate that a surface erosion threshold of as little as 1-3 cm depth can lead to failure of young seedlings. By monitoring accretion/erosion for 8 months along cross-shore transects in southwest Thailand, we show that especially on the bare mudflat, the physical sediment disturbance regularly exceed the critical erosion thresholds derived from the flume study. Physical sediment parameters along the same transects were analysed to deduct patterns of hydrodynamic energy attenuation. Grain size analysis and erosion/accretion data showed only limited energy dissipation within the fringing Avicennia/Sonneratia zone, sediment dynamics only dropped below for seedlings lethal values within the denser Rhizophora zone. Overall, present results emphasize that (i) seedling survival is extremely sensitive to physical-driven sediment dynamics and (ii) that such physical disturbances are not only present on the idal flats but can penetrate a significant distance into the forest. Spatio-temporal patterns in sediment dynamics should hence be considered when conducting restoration of mangrove ecosystems.

  5. Metagenomics-based analysis of viral communities in dairy lagoon wastewater.

    PubMed

    Alhamlan, F S; Ederer, M M; Brown, C J; Coats, E R; Crawford, R L

    2013-02-15

    Microbial populations, especially those of viruses, are poorly studied in dairy wastewater treatment operations. Here we report signature nucleic acid metagenomic sequences obtained by pyrosequencing viromes of virus-like particles that were extracted from two dairy waste treatment lagoons. The lagoons are operated in series, with Lagoon I being used as the primary stage and Lagoon II as the secondary stage of wastewater treatment. An average of 2000 sequences was obtained from each lagoon. More than 300 signatures from each lagoon matched sequences in the virus database of the National Center for Biotechnology Information (NCBI). We utilized a bioinformatics approach and transmission electron microscopy (TEM) to characterize the viral diversity and presence of potential viral pathogens within the lagoons. Our results showed differences in viral community compositions between Lagoon I and Lagoon II, suggesting that the viral community changes significantly in the transition of water between the two lagoons. Furthermore, the diverse viral community in the lagoon samples contained signature sequences of a variety of bacterial, plant, and animal viruses. Bacteriophage sequences dominated the viral community metagenomes in both lagoons. Ultimately these results can be used to identify viral bioindicators to rapidly assess wastewater treatment quality and the potential impacts of dairy operations on watersheds. Our viral metagenomic sequences have been submitted to GenBank (GPID 65805) and can provide insight into the composition and structure of viral communities within wastewaters of dairy lagoon systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Comparative hydrodynamics of 10 Mediterranean lagoons by means of numerical modeling

    NASA Astrophysics Data System (ADS)

    Umgiesser, Georg; Ferrarin, Christian; Cucco, Andrea; De Pascalis, Francesca; Bellafiore, Debora; Ghezzo, Michol; Bajo, Marco

    2014-04-01

    A comparison study between 10 Mediterranean lagoons has been carried out by means of the 3-D numerical model SHYFEM. The investigated basins are the Venice and Marano-Grado lagoons in the Northern Adriatic Sea, the Lesina and Varano lagoons in the Southern Adriatic Sea, the Taranto basin in the Ionian Sea, the Cabras Lagoon in Sardinia, the Ganzirri and Faro lagoons in Sicily, the Mar Menor in Spain, and the Nador Lagoon in Morocco. This study has been focused on hydrodynamics in terms of exchange rates, transport time scale, and mixing. Water exchange depends mainly on the inlet shape and tidal range, but also on the wind regimes in the case of multi-inlet lagoons. Water renewal time, which is mostly determined by the exchange rate, is a powerful concept that allows lagoons to be characterized with a time scale. In the case of the studied lagoons, the renewal time ranged from few days in the Marano-Grado Lagoon up to 1 year in the case of the Mar Menor. The analysis of the renewal time frequency distribution allows identifying subbasins. The numerical study proved to be a useful tool for the intercomparison and classification of the lagoons. These environments range from a leaky type to a choked type of lagoons and give a representative picture of the lagoons situated around the Mediterranean basin. Mixing efficiency turns out to be a function of the morphological complexity, but also of the forcings acting on the system.

  7. Mangrove sedimentation and response to relative sea-level rise

    USGS Publications Warehouse

    Woodroffe, CD; Rogers, K.; Mckee, Karen L.; Lovelock, CE; Mendelssohn, IA; Saintilan, N.

    2016-01-01

    Mangroves occur on upper intertidal shorelines in the tropics and subtropics. Complex hydrodynamic and salinity conditions influence mangrove distributions, primarily related to elevation and hydroperiod; this review considers how these adjust through time. Accumulation rates of allochthonous and autochthonous sediment, both inorganic and organic, vary between and within different settings. Abundant terrigenous sediment can form dynamic mudbanks; tides redistribute sediment, contrasting with mangrove peat in sediment-starved carbonate settings. Sediments underlying mangroves sequester carbon, but also contain paleoenvironmental records of adjustments to past sea-level changes. Radiometric dating indicates long-term sedimentation, whereas Surface Elevation Table-Marker Horizon measurements (SET-MH) provide shorter perspectives, indicating shallow subsurface processes of root growth and substrate autocompaction. Many tropical deltas also experience deep subsidence, which augments relative sea-level rise. The persistence of mangroves implies an ability to cope with moderately high rates of relative sea-level rise. However, many human pressures threaten mangroves, resulting in continuing decline in their extent throughout the tropics.

  8. Content of polyphenol compound in mangrove and macroalga extracts

    NASA Astrophysics Data System (ADS)

    Takarina, N. D.; Patria, M. P.

    2017-07-01

    Polyphenol or phenolic are compounds containing one or more hydroxyl group of the aromatic ring [1]. These compounds have some activities like antibacterial, antiseptic, and antioxidants. Natural resources like mangrove and macroalga were known containing these compounds. The purpose of the research was to investigate polyphenol content in mangrove and macroalga. Materials used in this research were mangrove (Avicennia sp.) leaves and the whole part of macroalga (Caulerpa racemosa). Samples were dried for 5 days then macerated in order to get an extract. Maceration were done using methanol for 48 hours (first) and 24 hours (second) continously. Polyphenol content was determined using phytochemical screening on both extracts. The quantitative test was carried out to determine catechin and tannin as polyphenol compound. The result showed that catechin was observed in both extracts while tannin in mangrove extract only. According to quantitative test, mangrove has a higher content of catechin and tannin which were 12.37-13.44 % compared to macroalga which was 2.57-4.58 %. Those indicated that both materials can be the source of polyphenol compound with higher content on mangrove. Moreover, according to this result, these resources can be utilized for advanced studies and human needs like medical drug.

  9. The Microbiome of Brazilian Mangrove Sediments as Revealed by Metagenomics

    PubMed Central

    Andreote, Fernando Dini; Jiménez, Diego Javier; Chaves, Diego; Dias, Armando Cavalcante Franco; Luvizotto, Danice Mazzer; Dini-Andreote, Francisco; Fasanella, Cristiane Cipola; Lopez, Maryeimy Varon; Baena, Sandra; Taketani, Rodrigo Gouvêa; de Melo, Itamar Soares

    2012-01-01

    Here we embark in a deep metagenomic survey that revealed the taxonomic and potential metabolic pathways aspects of mangrove sediment microbiology. The extraction of DNA from sediment samples and the direct application of pyrosequencing resulted in approximately 215 Mb of data from four distinct mangrove areas (BrMgv01 to 04) in Brazil. The taxonomic approaches applied revealed the dominance of Deltaproteobacteria and Gammaproteobacteria in the samples. Paired statistical analysis showed higher proportions of specific taxonomic groups in each dataset. The metabolic reconstruction indicated the possible occurrence of processes modulated by the prevailing conditions found in mangrove sediments. In terms of carbon cycling, the sequences indicated the prevalence of genes involved in the metabolism of methane, formaldehyde, and carbon dioxide. With respect to the nitrogen cycle, evidence for sequences associated with dissimilatory reduction of nitrate, nitrogen immobilization, and denitrification was detected. Sequences related to the production of adenylsulfate, sulfite, and H2S were relevant to the sulphur cycle. These data indicate that the microbial core involved in methane, nitrogen, and sulphur metabolism consists mainly of Burkholderiaceae, Planctomycetaceae, Rhodobacteraceae, and Desulfobacteraceae. Comparison of our data to datasets from soil and sea samples resulted in the allotment of the mangrove sediments between those samples. The results of this study add valuable data about the composition of microbial communities in mangroves and also shed light on possible transformations promoted by microbial organisms in mangrove sediments. PMID:22737213

  10. The microbiome of Brazilian mangrove sediments as revealed by metagenomics.

    PubMed

    Andreote, Fernando Dini; Jiménez, Diego Javier; Chaves, Diego; Dias, Armando Cavalcante Franco; Luvizotto, Danice Mazzer; Dini-Andreote, Francisco; Fasanella, Cristiane Cipola; Lopez, Maryeimy Varon; Baena, Sandra; Taketani, Rodrigo Gouvêa; de Melo, Itamar Soares

    2012-01-01

    Here we embark in a deep metagenomic survey that revealed the taxonomic and potential metabolic pathways aspects of mangrove sediment microbiology. The extraction of DNA from sediment samples and the direct application of pyrosequencing resulted in approximately 215 Mb of data from four distinct mangrove areas (BrMgv01 to 04) in Brazil. The taxonomic approaches applied revealed the dominance of Deltaproteobacteria and Gammaproteobacteria in the samples. Paired statistical analysis showed higher proportions of specific taxonomic groups in each dataset. The metabolic reconstruction indicated the possible occurrence of processes modulated by the prevailing conditions found in mangrove sediments. In terms of carbon cycling, the sequences indicated the prevalence of genes involved in the metabolism of methane, formaldehyde, and carbon dioxide. With respect to the nitrogen cycle, evidence for sequences associated with dissimilatory reduction of nitrate, nitrogen immobilization, and denitrification was detected. Sequences related to the production of adenylsulfate, sulfite, and H(2)S were relevant to the sulphur cycle. These data indicate that the microbial core involved in methane, nitrogen, and sulphur metabolism consists mainly of Burkholderiaceae, Planctomycetaceae, Rhodobacteraceae, and Desulfobacteraceae. Comparison of our data to datasets from soil and sea samples resulted in the allotment of the mangrove sediments between those samples. The results of this study add valuable data about the composition of microbial communities in mangroves and also shed light on possible transformations promoted by microbial organisms in mangrove sediments.

  11. Mangrove Sedimentation and Response to Relative Sea-Level Rise

    NASA Astrophysics Data System (ADS)

    Woodroffe, C. D.; Rogers, K.; McKee, K. L.; Lovelock, C. E.; Mendelssohn, I. A.; Saintilan, N.

    2016-01-01

    Mangroves occur on upper intertidal shorelines in the tropics and subtropics. Complex hydrodynamic and salinity conditions, related primarily to elevation and hydroperiod, influence mangrove distributions; this review considers how these distributions change over time. Accumulation rates of allochthonous and autochthonous sediment, both inorganic and organic, vary between and within different settings. Abundant terrigenous sediment can form dynamic mudbanks, and tides redistribute sediment, contrasting with mangrove peat in sediment-starved carbonate settings. Sediments underlying mangroves sequester carbon but also contain paleoenvironmental records of adjustments to past sea-level changes. Radiometric dating indicates long-term sedimentation, whereas measurements made using surface elevation tables and marker horizons provide shorter perspectives, indicating shallow subsurface processes of root growth and substrate autocompaction. Many tropical deltas also experience deep subsidence, which augments relative sea-level rise. The persistence of mangroves implies an ability to cope with moderately high rates of relative sea-level rise. However, many human pressures threaten mangroves, resulting in a continuing decline in their extent throughout the tropics. *

  12. Mapping discourses using Q methodology in Matang Mangrove Forest, Malaysia.

    PubMed

    Hugé, Jean; Vande Velde, Katherine; Benitez-Capistros, Francisco; Japay, Jan Harold; Satyanarayana, Behara; Nazrin Ishak, Mohammad; Quispe-Zuniga, Melissa; Mohd Lokman, Bin Husain; Sulong, Ibrahim; Koedam, Nico; Dahdouh-Guebas, Farid

    2016-12-01

    The sustainable management of natural resources requires the consideration of multiple stakeholders' perspectives and knowledge claims, in order to inform complex and possibly contentious decision-making dilemmas. Hence, a better understanding of why people in particular contexts do manage natural resources in a particular way is needed. Focusing on mangroves, highly productive tropical intertidal forests, this study's first aim is to map the diversity of subjective viewpoints among a range of stakeholders on the management of Matang Mangrove Forest in peninsular Malaysia. Secondly, this study aims to feed the reflection on the possible consequences of the diversity of perspectives for the future management of mangroves in Malaysia and beyond. The use of the semi-quantitative Q methodology allowed us to identify three main discourses on mangrove management: i. the optimization discourse, stressing the need to improve the current overall satisfactory management regime; ii. the 'change for the better' discourse, which focuses on increasingly participatory management and on ecotourism; and iii. the conservative 'business as usual' discourse. The existence of common points of connection between the discourses and their respective supporters provides opportunities for modifications of mangrove management regimes. Acknowledging this diversity of viewpoints, reflecting how different stakeholders see and talk about mangrove management, highlights the need to develop pro-active and resilient natural resource management approaches.

  13. Mangrove Sedimentation and Response to Relative Sea-Level Rise.

    PubMed

    Woodroffe, C D; Rogers, K; McKee, K L; Lovelock, C E; Mendelssohn, I A; Saintilan, N

    2016-01-01

    Mangroves occur on upper intertidal shorelines in the tropics and subtropics. Complex hydrodynamic and salinity conditions, related primarily to elevation and hydroperiod, influence mangrove distributions; this review considers how these distributions change over time. Accumulation rates of allochthonous and autochthonous sediment, both inorganic and organic, vary between and within different settings. Abundant terrigenous sediment can form dynamic mudbanks, and tides redistribute sediment, contrasting with mangrove peat in sediment-starved carbonate settings. Sediments underlying mangroves sequester carbon but also contain paleoenvironmental records of adjustments to past sea-level changes. Radiometric dating indicates long-term sedimentation, whereas measurements made using surface elevation tables and marker horizons provide shorter perspectives, indicating shallow subsurface processes of root growth and substrate autocompaction. Many tropical deltas also experience deep subsidence, which augments relative sea-level rise. The persistence of mangroves implies an ability to cope with moderately high rates of relative sea-level rise. However, many human pressures threaten mangroves, resulting in a continuing decline in their extent throughout the tropics.

  14. The freshwater artisanal fishery of Patos Lagoon.

    PubMed

    Ceni, G; Fontoura, N F; Cabral, H N

    2016-07-01

    In this study data relative to the fishery in the freshwater area of the Patos Lagoon are analysed, and the dynamics, fishing gears used and catches evaluated. The results reveal the existence of two fishery strategies: forbidden mesh size gillnets (FMG; <35 mm; square measure) and allowed mesh size gillnets (AMG; ≥35 mm; square measure). In total, 31 species were caught (AMG = 27 and FMG = 24), but selectivity due to mesh size was significant (P < 0·001). The FMG may be very harmful since it captures individuals of most species below size at first maturity, including the target species, the armoured catfish Loricariichthys anus (61% of the total catch). In addition, this gear is used throughout the year, including the closed season (CS; November to January), when the target species is reproducing. Target species for the AMG are larger in size, comprising mainly the mullet Mugil liza, the marine catfish Genidens barbus and the whitemouth croaker Micropogonias furnieri. AMS gillnets were not used during the CS. The use of FMG reveals the need for effective fishery law enforcement and the need for additional studies to assess the status of populations of the exploited species. © 2016 The Fisheries Society of the British Isles.

  15. Central Facilities Area Sewage Lagoon Evaluation

    SciTech Connect

    Mark R. Cole

    2013-12-01

    The Central Facilities Area (CFA), located in Butte County, Idaho, at the Idaho National Laboratory has an existing wastewater system to collect and treat sanitary wastewater and non-contact cooling water from the facility. The existing treatment facility consists of three cells: Cell #1 has a surface area of 1.7 acres, Cell #2 has a surface area of 10.3 acres, and Cell #3 has a surface area of 0.5 acres. If flows exceed the evaporative capacity of the cells, wastewater is discharged to a 73.5-acre land application site that uses a center-pivot irrigation sprinkler system. As flows at CFA have decreased in recent years, the amount of wastewater discharged to the land application site has decreased from 13.64 million gallons in 2004 to no discharge in 2012 and 2013. In addition to the decreasing need for land application, approximately 7.7 MG of supplemental water was added to the system in 2013 to maintain a water level and prevent the clay soil liners in the cells from drying out and “cracking.” The Idaho National Laboratory is concerned that the sewage lagoons and land application site may be oversized for current and future flows. A further concern is the sustainability of the large volumes of supplemental water that are added to the system according to current operational practices. Therefore, this study was initiated to evaluate the system capacity, operational practices, and potential improvement alternatives, as warranted.

  16. Spatio-Temporal Distribution of Amino Acids on the Surface Sediment of the Segara Anakan Lagoon, Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Woldeyohannes, Z.; Jennerjahn, T. C.

    2016-02-01

    Coastal lagoon sediments function as a site for mineralization and storage process of settled organic matter (OM) originating from different sources. Studying the geochemical processes in the coastal sediment would provide information related to the adjacent environmental activities and helps examining the processes occurring in the sediments in the course of degradation. In this study, the spacio-temporal abundance and composition of total hydrolysable amino acids was determined on the mangrove-fringed coastal lagoon sediments of Segara Anakan Lagoon (SAL), Java, Indonesia. Total organic carbon (Corg), total nitrogen (TN), carbon/nitrogen ratio (C:N), stable isotopic compositions of carbon (δ C) and nitrogen (δ°N), total hydrolysable amino acids (THAA) and hexosamines (THHA) were measured from the surface sediments. The surface sediment samples were collected from 11 stations during two sampling campaigns (SPICE II project) in February and September to represent the rainy and dry seasons, respectively. The sediment Corg and TN value of the stations were as high as 3.4% and 0.2% for the rainy, and 4.5% and 0.2% for the dry seasons, respectively. While the δ13Corg values showed a range between -24.83‰ and -27.9‰, the δ15N (‰) values range between 2.4‰ and 5.6‰ in the dry and rainy seasons. Correlation of the AA-C% and AA-N % contribution across the stations in the rainy and dry seasons were comparable (r2 = 0.6). However, AA-C% display a slight decrease from western to eastern area of SAL. C:N ratio of rainy and dry seasons showed a range between 23.8 - 7.9 and 36.4 - 7.3, respectively. which clearly marked that the stations are getting mixtures of OM from autochthonous and allochthonous OM sources. Results from the reactivity index (RI) and production of non-protein amino acid reveals strong positive correlation of the dry and rainy seasons. The β-alanine and γ-aminobutyric acids (1.9-3.6 mol%) fits well within the coastal sediment ranges. Glycine

  17. Spatial variation in recruitment of native and invasive sessile species onto oyster reefs in a temperate soft-bottom lagoon

    NASA Astrophysics Data System (ADS)

    Thomsen, M. S.; Silliman, B. R.; McGlathery, K. J.

    2007-03-01

    Although spatial variability in recruitment is a strong force structuring many marine communities, relatively few data exist on recruitment variability in sessile oyster reef communities. In a soft-bottom lagoon in Virginia, we tested if recruitment differed among three reefs situated across a mainland-lagoon-barrier-island transect and among elevations (>90-80, >80-70, >70-55 and >55-20 cm below MSL) on the lagoon reef. The most abundant taxa (the invasive algae Gracilaria vermiculophylla and Codium fragile and the indigenous oyster Crassostrea virginica and algae Ulva curvata) had highest recruitment at the lagoon reef, where propagule supply was likely highest. The mainland reef had lowest algal richness (1.4-3.1 panel -1) and abundances (<4% cover) compared to lagoon and island reefs (3.3-6.5 panel -1, 14-20%), but there were no differences between sites for animals. Overall, animals and algae were equally dominant at the mainland reef, whereas algae dominated at lagoon and island reefs. High water turbidity and suspended solids are typical algal stressors at mainland reefs, and these may account for the low algal abundance in that region. For many species (at least 9 out of 14) differences in recruitment success were observed over elevation differences as small as 10-30 cm, e.g. G. vermiculophylla and C. fragile mainly recruited up to >70-55 and >80-70 cm respectively (probably limited upward by desiccation), U. curvata down to >70-55 cm (probably limited downward by grazing or competition), whereas C. virginica recruited at all elevations. Animal richness was highest at the two lowest elevations (2.0-2.5 vs. 1.1-1.8 panel -1), but there was no effect of elevation on algae (3-6 panel -1) because of species substitutions between elevation levels. Thus, as in rocky intertidal systems, spatial variability in recruitment is important for community structure on oyster reefs, and if biodiversity is considered an important reef conservation goal, managers should

  18. Local survival of Dunlin wintering in California

    USGS Publications Warehouse

    Warnock, N.; Page, G.W.; Sandercock, B.K.

    1997-01-01

    We estimated local annual survival of 1,051 individually color-banded Dunlin (Calidris alpina) at Bolinas Lagoon, California from 1979 to 1992. Resighting rates for birds banded as adults varied significantly among years, and resighting rates for first-year birds varied by sex and year. No significant differences in local survival rates were found between males and females in any age classes. First-year birds had lower local survival rates than adults. We suspect that raptor predation accounted for much of this difference and other variation in survival rates. Adult Dunlin had lower local survival rates in the year of capture than in subsequent years. Variation in resighting of some groups of individuals including transient Dunlin may account for some differences. However, capture and release of Dunlin may induce short-term behavioral changes that increase the risk of depredation by avian predators within the first few days after capture.

  19. Nitrous oxide and methane emissions from the restored mangrove ecosystem of the Ciénaga Grande de Santa Marta, Colombia

    NASA Astrophysics Data System (ADS)

    Konnerup, Dennis; Betancourt-Portela, Julián Mauricio; Villamil, Carlos; Parra, Juan Pablo

    2014-03-01

    Most studies on emission of the greenhouse gases nitrous oxide (N2O) and methane (CH4) have been carried out in temperate areas so there is generally a lack of data from subtropical and tropical climates. A large part of the subtropical and tropical coastal wetlands consists of mangrove ecosystems, which have potential to act as sources of N2O and CH4. We measured N2O and CH4 emissions during 11 months in the brackish lagoon system Ciénaga Grande de Santa Marta (CGSM) on the Caribbean coast of Colombia. The area has been seriously influenced by human disturbance which resulted in approximately 60% mangrove mortality but the ecosystem is now being rehabilitated. In addition to N2O and CH4 emissions at four sampling sites, we also measured temperature, salinity, pH, dissolved oxygen (DO), redox potential, nitrite (NO2-), nitrate (NO3-), ammonium (NH4+) and organic material in the water and/or the sediment.

  20. Mangroves in peril: unprecedented degradation rates of peri-urban mangroves in Kenya

    NASA Astrophysics Data System (ADS)

    Bosire, J. O.; Kaino, J. J.; Olagoke, A. O.; Mwihaki, L. M.; Ogendi, G. M.; Kairo, J. G.; Berger, U.; Macharia, D.

    2013-10-01

    Marine ecosystems are experiencing unprecedentedly high degradation rates than any other ecosystem on the planet, which in some instances are up to four times that of rainforests. Mangrove ecosystems have especially been impacted by compounded anthropogenic pressures leading to significant cover reductions of between 35 and 50% (equivalent to 1-2% loss pa) for the last half century. The main objective of this study was to test the hypothesis that peri-urban mangroves suffering from compounded and intense pressures may be experiencing higher degradation rates than the global mean (and/or national mean for Kenya) using Mombasa mangroves (comprising of Tudor and Mwache creeks) as a case study. Stratified sampling was used to sample along 22 and 10 belt transects in Mwache and Tudor respectively, set to capture stand heterogeneity in terms of species composition and structure in addition to perceived human pressure gradients using proximity to human habitations as a proxy. We acquired SPOT (HRV/ HRVIR/ HRS) imageries of April 1994, May 2000 and January 2009 and a vector mangrove map of 1992 at a scale of 1 : 50 000 for cover change and species composition analysis. Results from image classification of the 2009 image had 80.23% overall accuracy and Cohen's Kappa of 0.77, thus proving satisfactory for use in this context. Structural data indicate that complexity index (CI) which captures stand structural development was higher in Mwache at 1.80 compared to Tudor at 1.71. From cover change data, Tudor had lost 86.9% of the forest between 1992 and 2009, compared to Mwache at 45.4% representing very high hitherto undocumented degradation rates of 5.1 and 2.7% pa, respectively. These unprecedentedly high degradation rates, which far exceed not only the national mean (for Kenya of 0.7% pa) but the global mean as well, strongly suggest that these mangroves are highly threatened due to compounded pressures. Strengthening of governance regimes through enforcement and compliance

  1. Mangroves in peril: unprecedented degradation rates of peri-urban mangroves in Kenya

    NASA Astrophysics Data System (ADS)

    Bosire, J. O.; Kaino, J. J.; Olagoke, A. O.; Mwihaki, L. M.; Ogendi, G. M.; Kairo, J. G.; Berger, U.; Macharia, D.

    2014-05-01

    Marine ecosystems are experiencing unprecedented degradation rates higher than any other ecosystem on the planet, which in some instances are up to 4 times those of rainforests. Mangrove ecosystems have especially been impacted by compounded anthropogenic pressures leading to significant cover reductions of between 35 and 50% (equivalent to 1-2% loss pa) for the last half century. The main objective of this study was to test the hypothesis that peri-urban mangroves suffering from compounded and intense pressures may be experiencing higher degradation rates than the global mean (and/or national mean for Kenya) using Mombasa mangroves (comprising Tudor and Mwache creeks) as a case study. Stratified sampling was used to sample along 22 and 10 belt transects in Mwache and Tudor respectively, set to capture stand heterogeneity in terms of species composition and structure in addition to perceived human pressure gradients using proximity to human habitations as a proxy. We acquired SPOT (HRV/ HRVIR/ HRS) images of April 1994, May 2000 and January 2009 and a vector mangrove map of 1992 at a scale of 1:50 000 for cover change and species composition analysis. Results from image classification of the 2009 image had 80.23% overall accuracy and Cohen's kappa of 0.77, thus proving satisfactory for use in this context. Structural data indicate that complexity index (CI) which captures stand structural development was higher in Mwache at 1.80 compared to Tudor at 1.71. From cover change data, Tudor lost 86.9% of the forest between 1992 and 2009, compared to Mwache at 45.4%, representing very high hitherto undocumented degradation rates of 5.1 and 2.7% pa, respectively. These unprecedentedly high degradation rates, which far exceed not only the national mean (for Kenya of 0.7% pa) but the global mean as well, strongly suggest that these mangroves are highly threatened due to compounded pressures. Strengthening of governance regimes through enforcement and compliance to halt

  2. The mangrove pump: The tidal flushing of animal burrows in a tropical mangrove forest determined from radionuclide budgets

    NASA Astrophysics Data System (ADS)

    Stieglitz, Thomas C.; Clark, Jordan F.; Hancock, Gary J.

    2013-02-01

    Intertidal mangrove forests contribute significantly to biogeochemical solute budgets of tropical and subtropical coastlines. A significant part of the biogeochemical cycling in mangrove ecosystems occurs within the subsurface of the forest floor. This subsurface source and the 'offshore' sink are linked by the tidally-driven movement of water through the mangrove forest floor. The tidal circulation through animal macro-burrows in the Coral Creek mangrove forest (area 3 km2) on Hinchinbrook Island (Australia) is documented by constructing mass balances of isotopes of radium and radon measured in the creek in 1997 and 2005 respectively. Isotope activities in burrows were found to be significantly greater than in the adjacent mangrove creek (e.g. for 222Rn, 680-1750 and 30-170 Bq m-3 in burrows and creek respectively). From isotope mass balances, a daily water circulation flux through burrows of 30.4 ± 4.7 L m-2 of forest floor is calculated. This study quantifies the underlying physical process, i.e. the tidal flushing of burrows, that supports significant and continuous exports of soluble organic and inorganic matter from mangrove forest floors to the coastal ocean. The potential significance of the circulation flux estimate is illustrated by up-scaling of the forest-scale estimates to the mangrove forests in the entire central Great Barrier Reef. This extrapolation indicates that the annual water flux circulated by this tidally-driven 'mangrove pump' is equivalent to as much as 20% (16-22%) of the total annual river discharge along the ca. 400 km long coastline of this region.

  3. Are mangroves in the tropical Atlantic ripe for invasion? Exotic mangrove trees in the forests of South Florida

    USGS Publications Warehouse

    Fourqurean, James W.; Smith, Thomas J.; Possley, Jennifer; Collins, Timothy M.; Lee, David; Namoff, Sandra

    2010-01-01

    Two species of mangrove trees of Indo-Pacific origin have naturalized in tropical Atlantic mangrove forests in South Florida after they were planted and nurtured in botanic gardens. Two Bruguiera gymnorrhiza trees that were planted in the intertidal zone in 1940 have given rise to a population of at least 86 trees growing interspersed with native mangrove species Rhizophora mangle, Avicennia germinans and Laguncularia racemosa along 100 m of shoreline; the population is expanding at a rate of 5.6% year-1. Molecular genetic analyses confirm very low genetic diversity, as expected from a population founded by two individuals. The maximumnumber of alleles at any locus was three, and we measured reduced heterozygosity compared to native-range populations. Lumnitzera racemosa was introduced multiple times during the 1960s and 1970s, it has spread rapidly into a forest composed of native R. mangle, A. germinans, Laguncularia racemosa and Conocarpus erectus and now occupies 60,500 m2 of mangrove forest with stem densities of 24,735 ha-1. We estimate the population growth rate of Lumnitzera racemosa to be between 17 and 23% year-1. Populations of both species of naturalized mangroves are dominated by young individuals. Given the long life and water-dispersed nature of propagules of the two exotic species, it is likely that they have spread beyond our survey area. We argue that the species-depauperate nature of tropical Atlantic mangrove forests and close taxonomic relatives in the more species-rich Indo-Pacific region result in the susceptibility of tropical Atlantic mangrove forests to invasion by Indo-Pacific mangrove species.

  4. Fate of cyanobacteria in drinking water treatment plant lagoon supernatant and sludge.

    PubMed

    Pestana, Carlos J; Reeve, Petra J; Sawade, Emma; Voldoire, Camille F; Newton, Kelly; Praptiwi, Radisti; Collingnon, Lea; Dreyfus, Jennifer; Hobson, Peter; Gaget, Virginie; Newcombe, Gayle

    2016-09-15

    In conventional water treatment processes, where the coagulation and flocculation steps are designed to remove particles from drinking water, cyanobacteria are also concentrated into the resultant sludge. As a consequence, cyanobacteria-laden sludge can act as a reservoir for metabolites such as taste and odour compounds and cyanotoxins. This can pose a significant risk to water quality where supernatant from the sludge treatment facility is returned to the inlet to the plant. In this study the complex processes that can take place in a sludge treatment lagoon were investigated. It was shown that cyanobacteria can proliferate in the conditions manifest in a sludge treatment lagoon, and that cyanobacteria can survive and produce metabolites for at least 10days in sludge. The major processes of metabolite release and degradation are very dependent on the physical, chemical and biological environment in the sludge treatment facility and it was not possible to accurately model the net effect. For the first time evidence is provided to suggest that there is a greater risk associated with recycling sludge supernatant than can be estimated from the raw water quality, as metabolite concentrations increased by up to 500% over several days after coagulation, attributed to increased metabolite production and/or cell proliferation in the sludge. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Biologically-controlled multiple equilibria of tidal landforms and the fate of the Venice lagoon

    NASA Astrophysics Data System (ADS)

    Marani, Marco; D'Alpaos, Andrea; Lanzoni, Stefano; Carniello, Luca; Rinaldo, Andrea

    2007-06-01

    Looking across a tidal landscape, can one foresee the signs of impending shifts among different geomorphological structures? This is a question of paramount importance considering the ecological, cultural and socio-economic relevance of tidal environments and their worldwide decline. In this Letter we argue affirmatively by introducing a model of the coupled tidal physical and biological processes. Multiple equilibria, and transitions among them, appear in the evolutionary dynamics of tidal landforms. Vegetation type, disturbances of the benthic biofilm, sediment availability and marine transgressions or regressions drive the bio-geomorphic evolution of the system. Our approach provides general quantitative routes to model the fate of tidal landforms, which we illustrate in the case of the Venice lagoon (Italy), for which a large body of empirical observations exists spanning at least five centuries. Such observations are reproduced by the model, which also predicts that salt marshes in the Venice lagoon may not survive climatic changes in the next century if IPCC's scenarios of high relative sea level rise occur.

  6. Vegetation and sediment characteristics in an expanding mangrove forest in New Zealand

    NASA Astrophysics Data System (ADS)

    Yang, Juan; Gao, Jay; Cheung, Alan; Liu, Baolin; Schwendenmann, Luitgard; Costello, Mark John

    2013-12-01

    Mangrove expansion in inlets has been widely observed in the North Island of New Zealand over recent decades. There is just one mangrove species in New Zealand, Avicennia marina var. resinifera. Our main objective was to investigate the response of mangroves to sedimentary patterns. Remote sensing and GIS was used to quantify the change in mangrove area. Vegetation and sediment characteristics were studied across seasons from December 2009 to August 2010. Comparison of digital images in 1940 and 2003 revealed that the mangrove area in our study inlet had increased by 21%. The mangroves created a rim of high fringe mangroves surrounding high-density but low height trees in the interior. The relatively low pH level and seasonally fluctuating pore water total dissolved salt (TDS) concentration reveal potentially stressful conditions in the interior mangrove zone, which may influence the forest structure in the interior.

  7. Biomonitoring approach with mussel Mytilus galloprovincialis (Lmk) and clam Ruditapes philippinarum (Adams and Reeve, 1850) in the Lagoon of Venice.

    PubMed

    Moschino, Vanessa; Delaney, Eugenia; Meneghetti, Francesca; Ros, Luisa Da

    2011-06-01

    Transplanted Mytilus galloprovincialis and native Ruditapes philippinarum were deployed in 10 sampling stations with different pollution impact within the Lagoon of Venice to evaluate the temporal variations and the suitability of the following cytochemical and histochemical biomarkers just as indicators of environmental stress: lysosomal membrane stability, lipofuscins, neutral lipids and lysosome to cytoplasm volume ratio. The physiological status of the organisms was also investigated by determining the survival in air capability and the reburrowing rate (clams). The biological parameters were assessed in June and October. Furthermore, for a better definition of the environmental aspects of the study sites, heavy metal, PAH and PCB concentrations were also evaluated in the sediments. As a whole, the biological responses examined in both species from all the sampling sites showed significant differences between the two seasonal campaigns, only lysosomal membrane stability exhibited less variability. Pollutants in sediments generally showed low-intermediate contamination levels, few hotspots persisting mostly in the inner areas of the lagoon, the most influenced by the industrial zone. Transplanted mussels were more responsive than native clams and the biological responses of both species varied temporally. The range of the spatial variability was always narrow and reflected only partially the broader variability shown by the chemical content in the sediments. In this sense, biological responses seemed to be particularly influenced by the high temporal and spatial heterogeneity that characterise the Lagoon of Venice, as well as most of the transitional environments.

  8. Geochemical characterization of seaplane lagoon sediments, Alameda Naval Air Station

    SciTech Connect

    Bono, A; Carroll, S; Esser, B; Luther, G W; O'Day, P; Randall, S

    1999-08-16

    Our objective in the characterization of sediments from Seaplane Lagoon at the Alameda Naval Air Station (NAS) was to determine the geochemical interactions that control the partitioning of cadmium, chromium, cobalt, copper, lead, mercury, nickel, and zinc between the sediments and the porewaters. Our approach was to collect several cores at the east outfall location of the Seaplane Lagoon. We determined the porewater chemistry by (1) making in situ micro-electrode measurements, (2) extracting porewaters, and (3) modeling geochemical reactions. We determined the sediment chemistry by measuring (1) elemental abundance, (2) mineralogy, and (3) trace-element speciation. This information should help the US Navy determine the long-term hazard of the sediments if they are left in place and the short-term hazard if they are dredged. We did not fully examine the geochemistry of sediments from the West Beach Landfill Wetlands site, because these sediments were distinct from the Seaplane Lagoon sediments. Our initial motivation for studying the Landfill Wetlands site was to determine the trace-element geochemistry in Seaplane Lagoon sediments that had been dredged and then disposed in the Landfill Wetlands. Unfortunately, the location of these dredged sediments is unknown. The cores we sampled were not from the Seaplane Lagoon.

  9. Fine and coarse components in surface sediments from Bikini Lagoon

    SciTech Connect

    Noshkin, V. E., LLNL

    1997-01-01

    In 1979, 21 years after the moratorium on nuclear testing in the Marshall Islands, surface sediment samples (to depths of 2 and 4 cm) were collected from 87 locations in the lagoon of Bikini Atoll, one of the two sites in the Marshall Islands used by the United States to test nuclear devices from 1946 through 1958. The main purpose for the collections was to map the distribution of long-lived man-made radionuclides associated with the bottom material. In addition the samples were processed to estimate the fraction of fine and coarse components to show, by comparison, what modifications occurred in the composition since the sediments were first described in samples collected before testing in 1946. Nuclear testing produced more finely divided material that is now found in the surface sediment layer over large areas of the lagoon and especially in regions of the lagoon and reef adjacent to test sites. The 5 cratering events alone at Bikini Atoll redistributed sufficient material to account for the higher inventory of fine material found over the surface 4 cm of the sediment of the lagoon. Although the fraction of fine material in the bottom sediments was altered by the nuclear events, the combined processes of formation, transport and deposition were not sufficiently dynamic to greatly change the general geographical features of the major sedimentary components over most of the lagoon floor.

  10. Phytoplankton assemblages in lateral lagoons of a large tropical reservoir.

    PubMed

    Ferrareze, M; Nogueira, M G

    2013-02-01

    This study aimed to analyse the composition and ecological attributes of the phytoplankton assemblages in four lateral lagoons and in the main channel of Rosana Reservoir (Paranapanema River, SE Brazil). Fieldwork was carried out in September and November/2004 and January, March, May and August/2005. A total of 283 taxa was identified. Zygnemaphyta was the most specious group, followed by Chlorophyta and Bacillariophyta. Higher richness, abundance and biomass were observed in the lagoons when compared with the river-reservoir sampling point, especially during the rainy period. Cryptophyceae and Bacillariophyceae dominated numerically. Cryptomonas brasiliensis Castro, Bicudo and Bicudo was the main species of the phytoplankton in terms of abundance and frequency of occurrence. The dynamics of the most important taxa are discussed and the results showed that the phytoplankton assemblages are mainly influenced by meteorological factors and nutrient availability (the main driving forces). Correlation analyses indicated that the assemblage abundance was limited by nutrient (nitrogen and phosphorus). The phytoplankton abundance influenced positively the zooplankton abundance, what indicates the prevalence of bottom-up control routes in the lateral lagoons system. The results validate the hypotheses that lateral lagoons have a prominent ecological role on the phytoplankton diversity, as already previously demonstrated for fish and zooplankton. Therefore, the incorporation of the lateral lagoons in environmental programmes should be a target strategy for the conservation of the regional aquatic biota, minimising the negative impact of the dam.

  11. [Nitrogen, phosphorus and the C/N ratio in superficial sediments of the lagoon of Chacopata, Sucre, Venezuela].

    PubMed

    Fuentes Hernández, M V

    2000-12-01

    The basal behaviour and relationship with organic carbon (Corg) content and prevailing granulometric fractions, of organic nitrogen (Norg), total phosphorus (P-total) and C/N ratio in surface sediments of Chacopata lagoon, Sucre State, Venezuela, were studied. Concentrations and spatial gradients were determined in sixteen stations following a common method for marine sediments. Norg concentrations varied between 0.102 and 0.510% (x = 0.237%), total phosphorus between 0.012 and 0.094% (x = 0.058%) and C/N ratio between 9.27 and 44.47 (x = 20.53). The higher contents of Norg and total phosphorus are from sections with an abundance of mangroves, marine phanerogams, macroalgae, benthonic biomass and migratory birds shelters. The C/N ratio shows the typical values for carbonated sediments, indicating that the nitrogenous compounds are rapidly degraded and the organic matter presents itself as humic substances. This parameter was moderately associated with silt and clay, and showed antagonism with sand, whereas Norg and phosphorus showed no correlation with them. The organic contribution is purely autochthonous: no anthropogenous contributions were found.

  12. Evaluating, predicting and mapping belowground carbon stores in Kenyan mangroves.

    PubMed

    Gress, Selena K; Huxham, Mark; Kairo, James G; Mugi, Lilian M; Briers, Robert A

    2017-01-01

    Despite covering only approximately 138 000 km(2) , mangroves are globally important carbon sinks with carbon density values three to four times that of terrestrial forests. A key challenge in evaluating the carbon benefits from mangrove forest conservation is the lack of rigorous spatially resolved estimates of mangrove sediment carbon stocks; most mangrove carbon is stored belowground. Previous work has focused on detailed estimations of carbon stores over relatively small areas, which has obvious limitations in terms of generality and scope of application. Most studies have focused only on quantifying the top 1 m of belowground carbon (BGC). Carbon stored at depths beyond 1 m, and the effects of mangrove species, location and environmental context on these stores, are poorly studied. This study investigated these variables at two sites (Gazi and Vanga in the south of Kenya) and used the data to produce a country-specific BGC predictive model for Kenya and map BGC store estimates throughout Kenya at spatial scales relevant for climate change research, forest management and REDD+ (reduced emissions from deforestation and degradation). The results revealed that mangrove species was the most reliable predictor of BGC; Rhizophora muronata had the highest mean BGC with 1485.5 t C ha(-1) . Applying the species-based predictive model to a base map of species distribution in Kenya for the year 2010 with a 2.5 m(2) resolution produced an estimate of 69.41 Mt C [±9.15 95% confidence interval (C.I.)] for BGC in Kenyan mangroves. When applied to a 1992 mangrove distribution map, the BGC estimate was 75.65 Mt C (±12.21 95% C.I.), an 8.3% loss in BGC stores between 1992 and 2010 in Kenya. The country-level mangrove map provides a valuable tool for assessing carbon stocks and visualizing the distribution of BGC. Estimates at the 2.5 m(2) resolution provide sufficient details for highlighting and prioritizing areas for mangrove conservation and restoration.

  13. Light attenuation in estuarine mangrove lakes

    NASA Astrophysics Data System (ADS)

    Frankovich, Thomas A.; Rudnick, David T.; Fourqurean, James W.

    2017-01-01

    Submerged aquatic vegetation (SAV) cover has declined in brackish lakes in the southern Everglades characterized by low water transparencies, emphasizing the need to evaluate the suitability of the aquatic medium for SAV growth and to identify the light attenuating components that contribute most to light attenuation. Underwater attenuation of downwards irradiance of photosynthetically active radiation (PAR) was determined over a three year period at 42 sites in shallow (<2 m depth) mangrove-surrounded lakes in two sub-estuaries in the coastal Everglades, Florida USA. Turbidity, chromophoric dissolved organic matter (CDOM), and phytoplankton chlorophyll a (chl a) were measured concurrently and their respective contributions to the light attenuation rate were estimated. Light transmission to the benthos relative to literature estimates of minimum requirements for SAV growth indicated that the underwater light environment was often unsuitable for SAV. Light attenuation rates (n = 417) corrected for solar elevation angles ranged from 0.16 m-1 to 9.83 m-1 with a mean of 1.73 m-1. High concentrations of CDOM with high specific light absorption contributed the most to light attenuation followed by turbidity and chl a. CDOM alone sufficiently reduces light transmission beyond the estimated limits for SAV growth, making it difficult for ecosystem managers to increase SAV abundance by management activities. Light limitation of SAV in these areas may be a persistent feature because of their proximity to CDOM source materials from the surrounding mangrove swamp. Increasing freshwater flow into these areas may dilute CDOM concentrations and improve the salinity and light climate for SAV communities.

  14. Shrimp Farms and Mangroves, Gulf of Fonseca

    NASA Technical Reports Server (NTRS)

    2002-01-01

    For decades, astronauts on space missions have documented land use changes around the world. In this pair of images, astronauts track the development of shrimp farming along the Honduran coastline of the Gulf of Fonseca between 1989 and 2001. Mariculture, primarily shrimp farming, has become a leading agricultural effort in Honduras. The regional transformation of large tracts of coastal swamps into shrimp farms blossomed throughout the 1990s. The top image was taken with color infrared film in 1989. Dense vegetation, like the coastal mangrove swamps and the forested slopes of Volcan Cosiguina show up as dark red. The bottom image, taken with color visible film by the crew of the most recent Space Shuttle mission in December 2001 shows that hundreds of square kilometers of coastal swamp, primarily in Honduras, have been converted to shrimp ponds. These appear as the light-colored, rectilinear land use pattern. The Honduras shrimp farms were hit hard by flooding after Hurricane Mitch in 1998, and a devastating virus in 1999-2000. It is not known how many of the ponds in this view are still functional. A vigorous debate continues about the sustainability of the shrimp farms and the impacts to the environment and coastal ecosystem due to mangrove clearing and mariculture waste production. Apart from the shrimp farms, the other prominent feature on these images is the impressive volcano Cosiguina, which erupted explosively in 1859 (the largest recorded eruption in the Western Hemisphere). Photograph STS-108-717-85 was taken in the December 2001 by the crew of Space Shuttle mission 108 using a Hasselblad camera with 250-mm lens. Photograph STS030-93-15 was taken in May 1989 using a Hasselblad camera and color infrared film. Both images are 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.

  15. Downed wood in Micronesian mangrove forests

    USGS Publications Warehouse

    Allen, J.A.; Ewel, K.C.; Keeland, B.D.; Tara, T.; Smith, T. J.

    2000-01-01

    Dead, downed wood is an important component of upland forest and aquatic ecosystems, but its role in wetland ecosystems, including mangroves, is poorly understood. We measured downed wood in ten sites on the western Pacific islands of Kosrae, Pohnpei, and Yap, all located within the Federated States of Micronesia. Our goals were to examine patterns of variability in the quantity of downed wood in these mangrove ecosystems, provide a general characterization of downed wood in a region with no previously published accounts, and investigate the relationship between harvesting practices and the amount of downed wood. The overall mean volume of downed wood at our study sites was estimated to be 60.8 m3 ha-1 (20.9 t ha-1), which is greater than most published data for forested wetlands. There were significant differences among islands, with the sites on Kosrae (104.2 m3 ha-1) having a much greater mean volume of downed wood than those on Pohnpei (43.1 m3 ha-1) or Yap (35.1 m3 ha-1). Part of the difference among islands may be attributable to differences in stand age and structure, but the most important factor seems to be the greater amount of wood harvesting on Kosrae, coupled with a low efficiency of use of cut trees. Of a total of 45 cut trees examined on Kosrae, no wood had been removed from 18 (40%); these are believed to be trees cut down because other, more valuable, trees were caught on them as they were felled. Of the other 27 trees, only 24 to 42% of the stem volume (to a 10 cm top) was removed from the forest, the amount varying by species. The impacts of current harvesting practices are unknown but may include important effects on tree regeneration and the abundance and species composition of crab populations.

  16. Shrimp Farms and Mangroves, Gulf of Fonseca

    NASA Technical Reports Server (NTRS)

    2002-01-01

    For decades, astronauts on space missions have documented land use changes around the world. In this pair of images, astronauts track the development of shrimp farming along the Honduran coastline of the Gulf of Fonseca between 1989 and 2001. Mariculture, primarily shrimp farming, has become a leading agricultural effort in Honduras. The regional transformation of large tracts of coastal swamps into shrimp farms blossomed throughout the 1990s. The top image was taken with color infrared film in 1989. Dense vegetation, like the coastal mangrove swamps and the forested slopes of Volcan Cosiguina show up as dark red. The bottom image, taken with color visible film by the crew of the most recent Space Shuttle mission in December 2001 shows that hundreds of square kilometers of coastal swamp, primarily in Honduras, have been converted to shrimp ponds. These appear as the light-colored, rectilinear land use pattern. The Honduras shrimp farms were hit hard by flooding after Hurricane Mitch in 1998, and a devastating virus in 1999-2000. It is not known how many of the ponds in this view are still functional. A vigorous debate continues about the sustainability of the shrimp farms and the impacts to the environment and coastal ecosystem due to mangrove clearing and mariculture waste production. Apart from the shrimp farms, the other prominent feature on these images is the impressive volcano Cosiguina, which erupted explosively in 1859 (the largest recorded eruption in the Western Hemisphere). Photograph STS-108-717-85 was taken in the December 2001 by the crew of Space Shuttle mission 108 using a Hasselblad camera with 250-mm lens. Photograph STS030-93-15 was taken in May 1989 using a Hasselblad camera and color infrared film. Both images are 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.

  17. An integrated approach to coastal rehabilitation: Mangrove restoration in Sungai Haji Dorani, Malaysia

    NASA Astrophysics Data System (ADS)

    Hashim, Roslan; Kamali, Babak; Tamin, Noraini Mohd; Zakaria, Rozainah

    2010-01-01

    To achieve an efficient method of coastal rehabilitation, a coastal structure was applied in combination with the mangrove restoration scheme in Sungai Haji Dorani where coastal forest over-cutting associated with erosion has resulted in severe coastline retreat. Such an attempt provides the opportunity to mitigate erosion as well as improve ecological and socio-economic aspects of coastal areas, both of which are of great importance to local communities and authorities. Beach morphological changes were monitored for an eight-month period of time. The results indicate that the attempt has been successful in retaining sediment on the beach and consequently raising the elevation of the site. While the monitoring schedule is required to continue for several years to evaluate long-term performance of the rehabilitation effort, approximately 30% of the transplanted mangrove saplings' survival after eight months shows that the project was moderately successful. Since the general conditions of the selected site represent the majority of the eroded shorelines on the west coast of Peninsular Malaysia, the method applied in this study can be replicated as an appropriate cost-effective alternative for the same cases.

  18. National Level Assessment of Mangrove Forest Cover in Pakistan

    NASA Astrophysics Data System (ADS)

    Abbas, S.; Qamer, F. M.; Hussain, N.; Saleem, R.; Nitin, K. T.

    2011-09-01

    Mangroves ecosystems consist of inter tidal flora and fauna found in the tropical and subtropical regions of the world. Mangroves forest is a collection of halophytic trees, shrubs, and other plants receiving inputs from regular tidal flushing and from freshwater streams and rivers. A global reduction of 25 % mangroves' area has been observed since 1980 and it is categorized as one of to the most threatened and vulnerable ecosystems of the world. Forest resources in Pakistan are being deteriorating both quantitatively and qualitatively due to anthropogenic activities, climatic v and loose institutional management. According to the FAO (2007), extent of forest cover of Pakistan in 2005 is 1,902,000 ha, which is 2.5% of its total land area. Annual change rate during 2000-2005 was -2.1% which is highest among all the countries in Asia. The Indus delta region contains the world's fifth-largest mangrove forest which provides a range of important ecosystem services, including coastal stabilisation, primary production and provision of nursery habitat for marine fish. Given their ecological importance in coastal settings, mangroves receive special attention in the assessment of conservation efforts and sustainable coastal developments. Coastline of Pakistan is 1050km long shared by the provinces, Sind (350km) and Baluchistan (700 km). The coastline, with typical arid subtropical climate, possesses five significant sites that are blessed with mangroves. In the Sindh province, mangroves are found in the Indus Delta and Sandspit. The Indus Delta is host to the most extensive mangroves areas and extends from Korangi Creek in the West to Sir Creek in the East, whereas Sandspit is a small locality in the West of Karachi city. In the Balochistan province, mangroves are located at three sites, Miani Hor, Kalmat Khor and Jiwani. Contemporary methods of Earth observation sciences are being incorporated as an integral part of environmental assessment related studies in coastal areas

  19. Ocean-lagoon water and plankton exchanges in a semi-closed pearl farming atoll lagoon (Ahe, Tuamotu archipelago, French Polynesia)

    NASA Astrophysics Data System (ADS)

    Pagano, M.; Rodier, M.; Guillaumot, C.; Thomas, Y.; Henry, K.; Andréfouët, S.

    2017-05-01

    In atoll lagoons, plankton richness is highly dependent on water exchange with the ocean through the atoll rim. However, the dynamics of the physical and biological fluxes at the lagoon-ocean interface remain poorly characterized. Here, we studied the combined effects of lagoon-ocean water exchanges and local environmental conditions on the phyto- and zooplankton abundance and community structure across the atoll lagoon rim of Ahe (Tuamotu Archipelago, French Polynesia). Plankton and environmental variables were monitored in May 2013 (i) at several stations inside and outside the lagoon and (ii) during time-series corresponding to ebb-flood tidal cycles in the two types of channels connecting the lagoon to the ocean: at the passage (300 m long and about 11 m deep) and in hoa (i.e reef-flat less than 50 cm depth). Our results highlight tidally-driven selective plankton exchanges between the lagoon and external ocean. Phytoplankton (chlorophyll-a) and zooplankton biomass were respectively 4 times and 7 times higher in the lagoon than at stations outside the atoll lagoon. Copepoda was the dominant zooplankton group at the oceanic station (>75% abundance) whereas meroplankton (with bivalve larvae most common) was dominant at the lagoon stations (54%), in the passage (55-82%) and in hoa (>80%). These differences between sites suggest a loss of bivalve larvae through export to the ocean and retention and/or increased production of copepods in the lagoon. The daily export of bivalve larvae represents a low percentage of the lagoon stock, in agreement with previously published larval dispersal numerical models. The retention of copepods could constitute a significant input of nutrients and organic matter (through excretion, feces release, decomposition, and remineralization) into the lagoon.

  20. Evaluation of short-rotation woody crops to stabilize a decommissioned swine lagoon

    Treesearch

    K.C. Dipesh; Rodney E. Will; Thomas C. Hennessey; Chad J. Penn

    2012-01-01

    Fast growing tree stands represent an environmentally friendly, less expensive method for stabilization of decommissioned animal production lagoons than traditional lagoon closure. We tested the feasibility of using short-rotation woody crops (SRWCs) in central Oklahoma to close a decommissioned swine lagoon by evaluating the growth performance and nutrient uptake of...

  1. A system for estimating bowen ratio And evaporation from waste lagoons

    USDA-ARS?s Scientific Manuscript database

    A low cost system was deployed above a swine waste lagoon to obtain estimates of Bowen ratios and characterize lagoon temperatures. The system consisted of humidity and temperature sensors and anemometers deployed above the lagoon, water temperature sensors, and a meteorological station located by t...

  2. Nutrient-Chlorophyll Relationships in the Indian River Lagoon, Florida(SEERS)

    EPA Science Inventory

    The Indian River Lagoon is a highly diverse estuary located along Florida’s Atlantic coast. The system is made up of the main stem and two side-lagoons: the Banana River and Mosquito Lagoon. We segmented the main stem into three sections based on spatial trends in water quality ...

  3. 75 FR 53960 - Chignik Lagoon Power Utility; Notice of Declaration of Intention and Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-02

    ... Energy Regulatory Commission Chignik Lagoon Power Utility; Notice of Declaration of Intention and... Lagoon Power Utility. e. Name of Project: Packers Creek Hydroelectric Project. f. Location: The proposed Packers Creek Hydroelectric Project will be located on Packers Creek, near the community of Chignik Lagoon...

  4. Nutrient-Chlorophyll Relationships in the Indian River Lagoon, Florida(SEERS)

    EPA Science Inventory

    The Indian River Lagoon is a highly diverse estuary located along Florida’s Atlantic coast. The system is made up of the main stem and two side-lagoons: the Banana River and Mosquito Lagoon. We segmented the main stem into three sections based on spatial trends in water quality ...

  5. Mangroves as a major source of soil carbon storage in adjacent seagrass meadows

    PubMed Central

    Chen, Guangcheng; Azkab, Muhammad Husni; Chmura, Gail L.; Chen, Shunyang; Sastrosuwondo, Pramudji; Ma, Zhiyuan; Dharmawan, I. Wayan Eka; Yin, Xijie; Chen, Bin

    2017-01-01

    Mangrove forests have the potential to export carbon to adjacent ecosystems but whether mangrove-derived organic carbon (OC) would enhance the soil OC storage in seagrass meadows adjacent to mangroves is unclear. In this study we examine the potential for the contribution of mangrove OC to seagrass soils on the coast of North Sulawesi, Indonesia. We found that seagrass meadows adjacent to mangroves had significantly higher soil OC concentrations, soil OC with lower δ 13C, and lower bulk density than those at the non-mangrove adjacent meadows. Soil OC storage to 30 cm depth ranged from 3.21 to 6.82 kg C m−2, and was also significantly higher at the mangrove adjacent meadows than those non-adjacent meadows. δ13C analyses revealed that mangrove OC contributed 34 to 83% to soil OC at the mangrove adjacent meadows. The δ13C value of seagrass plants was also different between the seagrasses adjacent to mangroves and those which were not, with lower values measured at the seagrasses adjacent to mangroves. Moreover, we found significant spatial variation in both soil OC concentration and storage, with values decreasing toward sea, and the contribution of mangrove-derived carbon also reduced with distance from the forest. PMID:28186151

  6. Sonneratia apetala Buch. Ham in the mangrove ecosystems of China: An invasive species or restoration species?

    Treesearch

    Hai Ren; Hongfang Lu; Weijun Shen; Charlie Huang; Qinfeng Guo; Zhi' an Li; Shuguang. Jian

    2010-01-01

    By the end of 1990s when China initiated a 10-year mangrove reforestation project, the mangrove forest area had decreased from250,000 to 15,000 ha. Over 80% of current Chinese mangroves are degraded secondary forests or plantations. As an initial restoration and reforestation effort, Sonneratia apetala, a native of...

  7. The causes of mangrove death on Yap, Palau, Pohnpei and Kosrae [Chapter II

    Treesearch

    Phil G. Cannon; Margie Falanruw; Francis Ruegorong; Rich MacKenzie; Katie Friday; Amy L. Ross-Davis; Sara M. Ashiglar; Ned B. Klopfenstein; Zhangfeng Liu; Mohammad Golabi; Chancy Thomas Iyekar

    2014-01-01

    The area of a massive mangrove dieback in Yinuf Mn Island, Yap, was selected as the first location to study mangrove dieback problems. Seawater and soil samples were collected from plots where the mangrove trees were dead/dying and these samples were analyzed for eight different seawater and soil floor properties. Seawater and soil properties from dead/dying/...

  8. Designing a mangrove research and demonstration forest in the Rufiji Delta, Tanzania

    Treesearch

    Mwita M. Mangora; Mwanahija S. Shalli; Immaculate S. Semesi; Marco A. Njana; Emmanuel J. Mwainunu; Jared E. Otieno; Elias Ntibasubile; Henry C. Mallya; Kusaga Mukama; Matiko Wambura; Nurdin A. Chamuya; Carl C. Trettin; Christina E. Stringer

    2016-01-01

    Despite the growing body of literature on science and management of mangroves, there is a considerable knowledge gap and uncertainty at local levels regarding the carbon pool size, variability of carbon sequestration and carbon stocks within mangrove forests, mechanisms that control carbon emissions from degradation of mangrove forests, impacts of conversion to other...

  9. Stand structure influences nekton community composition and provides protection from natural disturbance in Micronesian mangroves

    Treesearch

    Richard A. MacKenzie; Nicole. Cormier

    2012-01-01

    Structurally complex mangrove roots are thought to provide foraging habitat, predation refugia, and typhoon protection for resident fish, shrimp, and crabs. The spatially compact nature of Micronesian mangroves results in model ecosystems to test these ideas. Tidal creek nekton assemblages were compared among mangrove forests impacted by Typhoon Sudal and differing in...

  10. Mangroves as a major source of soil carbon storage in adjacent seagrass meadows

    NASA Astrophysics Data System (ADS)

    Chen, Guangcheng; Azkab, Muhammad Husni; Chmura, Gail L.; Chen, Shunyang; Sastrosuwondo, Pramudji; Ma, Zhiyuan; Dharmawan, I. Wayan Eka; Yin, Xijie; Chen, Bin

    2017-02-01

    Mangrove forests have the potential to export carbon to adjacent ecosystems but whether mangrove-derived organic carbon (OC) would enhance the soil OC storage in seagrass meadows adjacent to mangroves is unclear. In this study we examine the potential for the contribution of mangrove OC to seagrass soils on the coast of North Sulawesi, Indonesia. We found that seagrass meadows adjacent to mangroves had significantly higher soil OC concentrations, soil OC with lower δ 13C, and lower bulk density than those at the non-mangrove adjacent meadows. Soil OC storage to 30 cm depth ranged from 3.21 to 6.82 kg C m-2, and was also significantly higher at the mangrove adjacent meadows than those non-adjacent meadows. δ13C analyses revealed that mangrove OC contributed 34 to 83% to soil OC at the mangrove adjacent meadows. The δ13C value of seagrass plants was also different between the seagrasses adjacent to mangroves and those which were not, with lower values measured at the seagrasses adjacent to mangroves. Moreover, we found significant spatial variation in both soil OC concentration and storage, with values decreasing toward sea, and the contribution of mangrove-derived carbon also reduced with distance from the forest.

  11. Vulnerability to Climate Change of Mangroves: Assessment from Cameroon, Central Africa

    PubMed Central

    Ellison, Joanna C.; Zouh, Isabella

    2012-01-01

    Intertidal mangrove ecosystems are sensitive to climate change impacts, particularly to associated relative sea level rise. Human stressors and low tidal range add to vulnerability, both characteristics of the Doula Estuary, Cameroon. To investigate vulnerability, spatial techniques were combined with ground surveys to map distributions of mangrove zones, and compare with historical spatial records to quantify change over the last few decades. Low technology techniques were used to establish the tidal range and relative elevation of the mapped mangrove area. Stratigraphic coring and palaeobiological reconstruction were used to show the longer term biological history of mangroves and net sedimentation rate, and oral history surveys of local communities were used to provide evidence of recent change and identify possible causes. Results showed that the seaward edge of mangroves had over two thirds of the shoreline experienced dieback at up to 3 m per year over the last three decades, and an offshore mangrove island had suffered 89% loss. Results also showed low net sedimentation rates under seaward edge mangroves, and restricted intertidal elevation habitats of all mangroves, and Avicennia and Laguncularia in particular. To reduce vulnerability, adaptation planning can be improved by reducing the non-climate stressors on the mangrove area, particularly those resulting from human impacts. Other priorities for adaptation planning in mangrove areas that are located in such low tidal range regions are to plan inland migration areas and strategic protected areas for mangroves, and to undertake management activities that enhance accretion within the mangroves. PMID:24832511

  12. The assessment of mangrove biomass and carbon in West Africa: a spatially explicit analytical framework

    Treesearch

    Wenwu Tang; Wenpeng Feng; Meijuan Jia; Jiyang Shi; Huifang Zuo; Carl C. Trettin

    2015-01-01

    Mangrove forests are highly productive and have large carbon sinks while also providing numerous goods and ecosystem services. However, effective management and conservation of the mangrove forests are often dependent on spatially explicit assessments of the resource. Given the remote and highly dispersed nature of mangroves, estimation of biomass and carbon...

  13. Water sources in mangroves in four hydrogeomorphic settings in Florida and Mexico

    Treesearch

    Christina Stringer; Mark. Rains

    2016-01-01

    Mangroves are transitional environments, where fresh water from the terrestrial environments mix with seawater from the marine environment. The relative contributions of these sources vary and play a role in controlling the physical and chemical hydrological characteristics of mangroves and facilitate the exchange of mass, energy, and organisms between mangroves and...

  14. Evolution and vitality of seagrasses in a Mediterranean lagoon.

    PubMed

    Ferrat, Lila; Fernandez, C; Pasqualini, V; Pergent, G; Pergent-Martini, C

    2003-08-01

    Despite their registration on the list of the Ramsar convention sites, the Mediterranean lagoons rarely beneficiate of an effective protection, and are particularly sensitive to environmental quality. A control of these wetlands needs the creation of an inventory of knowledge for the concerned environment. In this perspective, the seagrass beds were followed up in the coastal lagoon of Urbino (Corse, France) since 1990. A cartographic study was carried out by remote sensing of aerial photography. Temporal evolution of the seagrass beds (Cymodocea nodosa principally) allows to determine the vitality of these structures. A comparison of the surface areas occupied by Cymodocea nodosa, between 1990 and 1999, did not allow seeing any significant evolution. However, some variations appear like biotopes all more fragile and coveted as the Mediterranean coastal fringe is straight and is the privileged site of appear in the localization of the beds, due to the modification of environmental conditions in the lagoon.

  15. LANDSAT imagery of the Venetian Lagoon: A multitemporal analysis

    NASA Technical Reports Server (NTRS)

    Alberotanza, L.; Zandonella, A. (Principal Investigator)

    1980-01-01

    The use of LANDSAT multispectral scanner images from 1975 to 1979 to determine pollution dispersion in the central basin of the lagoon under varying tidal conditions is described. Images taken during the late spring and representing both short and long range tidal dynamics were processed for partial haze removal and removal of residual striping. Selected spectral bands were correlated to different types of turbid water. The multitemporal data was calibrated, classified considering sea truth data, and evaluated. The classification differentiated tide diffusion, algae belts, and industrial, agricultural, and urban turbidity distributions. Pollution concentration is derived during the short time interval between inflow and outflow and from the distance between the two lagoon inlets and the industrial zones. Increasing pollution of the lagoon is indicated.

  16. Testing lagoonal sediments with early life stages of the copepod Acartia tonsa (Dana): An approach to assess sediment toxicity in the Venice Lagoon.

    PubMed

    Picone, Marco; Bergamin, Martina; Delaney, Eugenia; Ghirardini, Annamaria Volpi; Kusk, Kresten Ole

    2017-08-24

    The early-life stages of development of the calanoid copepod Acartia tonsa from egg to copepodite I is proposed as an endpoint for assessing sediment toxicity by exposing newly released eggs directly onto the sediment-water interface. A preliminary study of 5 sediment samples collected in the lagoon of Venice highlighted that the larval development rate (LDR) and the early-life stages (ELS) mortality endpoints with A. tonsa are more sensitive than the standard amphipod mortality test; moreover LDR resulted in a more reliable endpoint than ELS mortality, due to the interference of the sediment with the recovery of unhatched eggs and dead larvae. The LDR data collected in a definitive study of 48 sediment samples from the Venice Lagoon has been analysed together with the preliminary data to evaluate the statistical performances of the bioassay (among replicate variance and minimum significant difference between samples and control) and to investigate the possible correlation with sediment chemistry and physical properties. The results showed that statistical performances of the LDR test with A. tonsa correspond with the outcomes of other tests applied to the sediment-water interface (Strongylocentrotus purpuratus embryotoxicity test), sediments (Neanthes arenaceodentata survival and growth test) and porewater (S. purpuratus); the LDR endpoint did, however, show a slightly higher variance as compared with other tests used in the Lagoon of Venice, such as 10-d amphipod lethality test and larval development with sea urchin and bivalves embryos. Sediment toxicity data highlighted the high sensitivity and the clear ability of the larval development to discriminate among sediments characterized by different levels of contamination. The data of the definitive study evidenced that inhibition of the larval development was not affected by grain-size and the organic carbon content of the sediment; in contrast, a strong correlation between inhibition of the larval development

  17. Mangrove plantation over a limestone reef - Good for the ecology?

    NASA Astrophysics Data System (ADS)

    Asaeda, Takashi; Barnuevo, Abner; Sanjaya, Kelum; Fortes, Miguel D.; Kanesaka, Yoshikazu; Wolanski, Eric

    2016-05-01

    There have been efforts to restore degraded tropical and subtropical mangrove forests. While there have been many failures, there have been some successes but these were seldom evaluated to test to what level the created mangrove wetlands reproduce the characteristics of the natural ecosystem and thus what ecosystem services they can deliver. We provide such a detailed assessment for the case of Olango and Banacon Islands in the Philippines where the forest was created over a limestone reef where mangroves did not exist in one island but they covered most of the other island before deforestation in the 1940s and 1950s. The created forest appears to have reached a steady state after 60 years. As is typical of mangrove rehabilitation efforts worldwide, planting was limited to a single Rhizophora species. While a forest has been created, it does not mimic a natural forest. There is a large difference between the natural and planted forests in terms of forest structure and species diversity, and tree density. The high density of planted trees excludes importing other species from nearby natural forests; therefore the planted forest remains mono-specific even after several decades and shows no sign of mimicking the characteristics of a natural forest. The planted forests provided mangrove propagules that invaded nearby natural forests. The planted forest has also changed the substratum from sandy to muddy. The outline of the crown of the planted forest has become smooth and horizontal, contrary to that of a natural forest, and this changes the local landscape. Thus we recommend that future mangrove restoration schemes should modify their methodology in order to plant several species, maintain sufficient space between trees for growth, include the naturally dominant species, and create tidal creeks, in order to reproduce in the rehabilitated areas some of the key ecosystem characteristics of natural mangrove forests.

  18. Blue Carbon distribution in mangrove forests of the Americas

    NASA Astrophysics Data System (ADS)

    Simard, M.; Rivera-Monroy, V.; Fatoyinbo, T. E.; Roy Chowdhury, R.

    2013-12-01

    Globally, coastal ecosystems are critical to maintaining human livelihood and biodiversity. These ecosystems including mangroves, salt marshes, and sea grasses provide essential ecosystem services, such as supporting fisheries by providing important spawning grounds, filtering pollutants and contaminants from coastal waters, and protecting coastal development and communities against storms, floods and erosion. Additionally, recent research indicates that these vegetated coastal ecosystems are highly efficient carbon sinks (i.e. 'Blue Carbon') and can potentially play a significant role in ameliorating the effect of increasing global climate change by capturing significant amounts of carbon into sediments and plant biomass. The term blue carbon indicates the carbon stored in coastal vegetated wetlands (i.e., mangroves, intertidal marshes, and seagrass meadows). As a result of rapid global changes in coastal regions, it is crucial that we improve our understanding of the current and future state of the remaining coastal ecosystems and associated ecosystem services and their vulnerability to global climate change. In this study, we present a continental scale study of mangrove distribution and assess patterns of forest structural development associated to latitude and geomorphological setting. We produced a baseline map of mangrove canopy height and biomass for all mangrove forests of the Americas using data from the Shuttle Radar Topography Mission (SRTM) and publicly available land cover maps (Figure 1). The resulting canopy height map was calibrated using ICEsat/Geoscience Laser Altimeter system (GLAS). Biomass was derived from field data and allometry. The maps were validated with field data and results in accuracies that vary spatially around 2 to 3m in height and 20% in biomass. Figure 1: Global distribution of mangrove forests (green) and SRTM elevation data. These data were used to produce large scale maps of mangrove canopy height and biomass.

  19. State Waste Discharge Permit application, 100-N Sewage Lagoon

    SciTech Connect

    Not Available

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations (Ecology et al. 1994), the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173--216 (or 173--218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order No. DE 91NM-177, (Ecology and DOE-RL 1991). This document constitutes the State Waste Discharge Permit application for the 100-N Sewage Lagoon. Since the influent to the sewer lagoon is domestic waste water, the State Waste Discharge Permit application for Public Owned Treatment Works Discharges to Land was used. Although the 100-N Sewage Lagoon is not a Public Owned Treatment Works, the Public Owned Treatment Works application is more applicable than the application for industrial waste water. The 100-N Sewage Lagoon serves the 100-N Area and other Hanford Site areas by receiving domestic waste from two sources. A network of sanitary sewer piping and lift stations transfers domestic waste water from the 100-N Area buildings directly to the 100-N Sewage Lagoon. Waste is also received by trucks that transport domestic waste pumped from on site septic tanks and holding tanks. Three ponds comprise the 100-N Sewage Lagoon treatment system. These include a lined aeration pond and stabilization pond, as well as an unlined infiltration pond. Both piped-in and trucked-in domestic waste is discharged directly into the aeration pond.

  20. Eutrophication Process on Coastal Lagoons of North of Sinaloa, Mexico

    NASA Astrophysics Data System (ADS)

    Escobedo-Urias, D.; Martinez-Lopez, A.

    2007-05-01

    Coastal ecosystems in the Gulf of California support diverse and important fisheries and are reservoirs of great biological diversity. In northern Sinaloa, population growth and development, as well as increased use of these natural systems for recreation, has substantially increased the pressure placed upon marine resources. Discharge of untreated wastewaters generated by diverse human activities has been notably altered its health and integrity, principally along the lagoon's eastern shore In the late 60s, agriculture moved into a dominant role in coastal northern Sinaloa. The coastal plain encompasses more than 200,000 hectares under cultivation that now introduces large amounts of organic material, pesticides, heavy metals, and fertilizers into the lagoon systems of Topolobampo and San Ignacio-Navachiste-Macapule System at drainage discharge points and a minor grade in Colorado Lagoon. These lagoons are shallow and exhibit low water quality, lost of lagoon depth, presence of toxic substances (heavy metals) near the discharge points of wastewaters, and presence of harmful algal blooms. With the aim of evaluate the nutrients loadings (wastewaters, groundwaters) and their effects on the coastal lagoons of north of Sinaloa, the preliminary analysis of the physical, chemical and biologic variables data series are analyzed. From 1987-2007 eutrophication process is identified in Topolobampo Complex show increase tendency in annual average concentrations of DIN (Dissolved Inorganic Nitrogen= NO2+NO3) from 0.5 μ M in 1987 to 2.7 μ M in 2006. Trophic Index (TRIX) values, low nutrient ratios (N: P and N: Si) and the phytoplanktonic community structure support this result. Preliminary results of nutrients loadings show a mayor contribution of wastewaters into the coastal zone.

  1. Spreading lagooned sewage sludge on farm land: A case history

    SciTech Connect

    Robson, C.M.; Sommers, L.E.

    1995-06-01

    This report describes the development of a project involving the application of approximately 265,000 cubic meters of lagooned sewage sludge from a metropolitan area on privately-owned farm land in an adjacent, rural county. The sludge application project was initiated to enable use of the land occupied by the lagoons for expansion of the sewage treatment plant. The procedures developed will be valuable to those proposing to practice land disposal of stabilized sludge as part of the Nation`s resource conservation program.

  2. Population studies on the Amphipoda of Mazoma Lagoon (Greece)

    NASA Astrophysics Data System (ADS)

    Karakiri, Maria; Nicolaidou, Artemis

    1987-12-01

    The life cycles of four amphipod species— Gammarus insensibilis, Dexamine spinosa, Microdeutopus gryllotalpa and Corophium insidiosum—were studied in the brackish-water lagoon Mazoma of the Amvrakikos Gulf, Ionian Sea. G. insensibilis has an annual life cycle with limited recruitment over the year and maximum reproductive activity in the winter months. D. spinosa exhibits continuous recruitment in the lagoon with a maximum in summer. Both species produce a single brood per female per yer. Continuous recruitment was observed during the summer months for M. gryllotalpa and C. insidiosum, and multiple breeding per female per year. Sex ratios varied considerably over the year, with a persisting preponderance of the females.

  3. Optical researches for cyanobacteria bloom monitoring in Curonian Lagoon

    NASA Astrophysics Data System (ADS)

    Shirshin, Evgeny A.; Budylin, Gleb B.; Yakimov, Boris P.; Voloshina, Olga V.; Karabashev, Genrik S.; Evdoshenko, Marina A.; Fadeev, Victor V.

    2016-04-01

    Cyanobacteria bloom is a great ecological problem of Curonian Lagoon and Baltic Sea. The development of novel methods for the on-line control of cyanobacteria concentration and, moreover, for prediction of bloom spreading is of interest for monitoring the state of ecosystem. Here, we report the results of the joint application of hyperspectral measurements and remote sensing of Curonian Lagoon in July 2015 aimed at the assessment of cyanobacteria communities. We show that hyperspectral data allow on-line detection and qualitative estimation of cyanobacteria concentration, while the remote sensing data indicate the possibility of cyanobacteria bloom detection using the spectral features of upwelling irradiation.

  4. Comparison of flooding-tolerance in four mangrove species in a diurnal tidal zone in the Beibu Gulf

    NASA Astrophysics Data System (ADS)

    He, Binyuan; Lai, Tinghe; Fan, Hangqing; Wang, Wenqing; Zheng, Hailei

    2007-08-01

    The flood tolerance of four mangrove species, Aegiceras corniculatum (L.) Blanco (AC), Avicennia marina (Forsk.) Vierh. (Am), Bruguiera gymnorrhiza (L.) Savigny (Bg) and Rhizophora stylosa Griff. (Rs) was examined in a field trial conducted from August 2004 until August 2005 in a diurnal tidal zone in Yingluo Bay, Guangxi province, China. In a section of tidal flat, three replicate artificial platforms were constructed for seedling cultivation. Eight different tidal flat elevation (TFE) treatments were created on each platform. After one year of cultivation under the TFE treatments, the survival rate and growth parameters of seedlings were measured. Seedlings of A. corniculatum and A. marina seedlings survived all treatments. The survival rate of B. gymnorrhiza and R. stylosa seedlings, however, decreased sharply as the TFE fell; in any treatment, fewer B. gymnorrhiza seedlings survived than R. stylosa seedlings. Stem elongation in A. corniculatum and A. marina seedlings was significantly increased by lower TFEs. Lower TFE treatments also increased stem heights in B. gymnorrhiza and R. stylosa seedlings; however, growth was significantly higher as TFE increased. Leaf number, leaf conservation rate and leaf area per seedling changed relatively little among treatments in A. corniculatum and A. marina seedlings, while these three indexes in B. gymnorrhiza and R. stylosa seedlings all decreased dramatically with decreasing TFE. A. marina seedlings reached a higher neonatal biomass at lower TFE treatments, whereas A. corniculatum seedlings attained a higher biomass under moderate TFEs. In contrast, B. gymnorrhiza and R. stylosa seedlings accumulated more biomass in the higher TFEs habitats. Biomass partitioning among the components of both A. corniculatum and A. marina seedlings changed evenly; however, A. corniculatum accumulated more biomass in the leaf while A. marina accumulated more in the stem. The TFE treatments greatly influenced biomass partitioning in B

  5. Annual survival and site fidelity of Stellar's Eiders molting along the Alaska Peninsula

    USGS Publications Warehouse

    Flint, P.L.; Petersen, M.R.; Dau, C.P.; Hines, J.E.; Nichols, J.D.

    2000-01-01

    Populations of Steller?s eiders (Polysticta stelleri) molting and wintering along the Alaska Peninsula have declined since the 1960's. We captured and marked a large sample of Steller's eiders molting in 2 lagoons along the Alaska Peninsula between 1975-97. We used mark-recapture analysis techniques to estimate annual survival and movement probabilities within and among lagoons for male and female eiders. Estimates of annual survival (?SE) were 0.899 ? 0.032 for females and 0.765 ? 0.044 for males. Both sexes showed high rates of fidelity to specific molting locations (>95%) within lagoons; yet we found no evidence that annual probability of survival differed among groups molting in different locations either within or among lagoons. We found weak evidence that annual survival decreased between the periods 1975-81 and 1991-97. The lower survival of males compared to females is unusual for waterfowl and may result in a female-biased sex ratio. We conclude that a decrease in adult survival may have initiated the long-term population decline. Further, a shortage of males may be limiting reproductive potential.

  6. Annual survival and site fidelity of Steller's eiders molting along the Alaska Peninsula

    USGS Publications Warehouse

    Flint, P.L.; Petersen, M.R.; Dau, C.P.; Hines, J.E.; Nichols, J.D.

    2000-01-01

    Populations of Steller's eiders (Polysticta stelleri) molting and wintering along the Alaska Peninsula have declined since the 1960's. We captured and marked a large sample of Steller's eiders molting in 2 lagoons along the Alaska Peninsula between 1975-97. We used mark-recapture analysis techniques to estimate annual survival and movement probabilities within and among lagoons for male and female eiders. Estimates of annual survival (??SE) were 0.899 ?? 0.032 for females and 0.765 ?? 0.044 for males. Both sexes showed high rates of fidelity to specific molting locations (>95%) within lagoons; yet we found no evidence that annual probability of survival differed among groups molting in different locations either within or among lagoons. We found weak evidence that annual survival decreased between the periods 1975-81 and 1991-97. The lower survival of males compared to females is unusual for waterfowl and may result in a female-biased sex ratio. We conclude that a decrease in adult survival may have initiated the long-term population decline. Further, a shortage of males may be limiting reproductive potential.

  7. Rare Earth elements as sediment tracers in Mangrove ecosystems

    NASA Astrophysics Data System (ADS)

    Ramanathan, A. L.; Swathi, S.

    2013-05-01

    Rare earth elements have been widely used as geochemical source fingerprints of rocks and sediments to study processes involving cosmo-chemistry, igneous petrology, tectonic setting and for investigations of water-rock interactions and weathering processes including transport of weathering products to the oceans.Many studies have addressed the use of REEs in investigating the environmental impact of human activity and demonstrated that the REE natural distribution in sediment from densely industrialised and populated regions can be altered by anthropogenic influences.The coastal wetlands like Mangroves are ultimate sinks for all the material derived from the terrestrial and marine environment.The high productivity and low ratio of sediment respiration to net primary production gives mangrove sediments the potential for long-term sequestration of these pollutants/metals before reaching the coastal ocean. Geochemical study of REE in these sedimentary systems is useful for determining the nature of the biogeochemical processes. In particular, REE show a great sensitivity to pH changes, redox conditions and adsorption/ desorption reactions. So, they may be used as markers of discharge provenance, weathering processes, changes in environmental conditions in the water and sediments of Mangrove/wetland systems. Our study aims to establish the abundance, distribution and enrichment of REEs to track the sediment sources and biogeochemical processes occurring in the mangrove environment.Core sediments were collected from the different environmental settings within the Pichavaram mangrove area.Higher REE concentration in Pichavaram sediments indicated greater input from sources like terrestrial weathering and anthropogenic activities which in turn are affected by saline mixing and dynamic physico-chemical processes occurring in the mangrove environment. REE enrichment order was attributed to the alkaline pH (7-8.5) and reducing conditions prevailing in the mangrove

  8. Soil Respiration of Three Mangrove Forests on Sanibel Island, Florida

    NASA Astrophysics Data System (ADS)

    Cartwright, F.; Bovard, B. D.

    2011-12-01

    Carbon cycling studies conducted in mangrove forests have typically focused on aboveground processes. Our understanding of carbon storage in these systems is therefore limited by the lack information on belowground processes such as fine root production and soil respiration. To our knowledge there exist no studies investigating temporal patterns in and environmental controls on soil respiration in multiple types of mangrove ecosystems concurrently. This study is part of a larger study on carbon storage in three mangrove forests on Sanibel Island, Florida. Here we report on eight months of soil respiration data within these forests that will ultimately be incorporated into an annual carbon budget for each habitat type. Soil respiration was monitored in the following three mangrove habitat types: a fringe mangrove forest dominated by Rhizophora mangle, a basin mangrove forest dominated by Avicennia germinans, and a higher elevation forest comprised of a mix of Avicennia germinans and Laguncularia racemosa, and non-woody salt marsh species. Beginning in June of 2010, we measured soil emissions of carbon dioxide at 5 random locations within three-100 m2 plots within each habitat type. Sampling was performed at monthly intervals and conducted over the course of three days. For each day, one plot from each habitat type was measured. In addition to soil respiration, soil temperature, salinity and gravimetric moisture content were also measured. Our data indicate the Black mangrove forest, dominated by Avicennia germinans, experiences the highest rates of soil respiration with a mean rate of 4.61 ± 0.60 μmol CO2 m-2 s-1. The mixed mangrove and salt marsh habitat has the lowest soil carbon emission rates with a mean of 2.78 ± 0.40 μmol CO2 m-2 s-1. Soil carbon effluxes appear to peak in the early part of the wet season around May to June and are lower and relatively constant the remainder of the year. Our data also suggest there are important but brief periods where

  9. Sediment budget in the Lagoon of Venice, Italy

    NASA Astrophysics Data System (ADS)

    Sarretta, A.; Pillon, S.; Molinaroli, E.; Guerzoni, S.; Fontolan, G.

    2010-05-01

    A comparison of 1927, 1970 and 2002 bathymetric surveys in the Lagoon of Venice was used to reconstruct historical changes in sedimentation. A detailed GIS-based analysis of the charts revealed the timing and pattern of geomorphic changes and allowed calculation of sediment deposition and erosion for the entire lagoon and each of its four sub-basins: Treporti, Lido, Malamocco and Chioggia. Two main developments are discernible from comparative observation of the areal distribution of the main elevation ranges: the diminution in area of the saltmarshes, which decreased by more than 50%, from 68 km 2 in 1927 to 32 km 2 in 2002, and the progressive deepening of the lagoon, with a huge increase in the area of subtidal flats (between -0.75 and -2.00 m depth), from 88 to 206 km 2 during the same period. Generally, the lagoon showed a clear-cut change in the most frequent depths (modal depth) from a value of -0.62 m in 1927 to -0.88 m in 2002. The deepening of the lagoon affected mostly the lagoonal sub-basins south of the town of Venice, where modal depth increased from -0.65 to -1.12 m in Lido, from -0.64 to -1.75 m in Malamocco and from -0.39 to -0.88 m in Chioggia. Large changes in lagoonal morphology were caused by human-induced subsidence, the dredging of navigation channels between 1927 and 1970, and intense natural erosion enhanced by sediment re-suspension due to Manila clam fishing between 1970 and 2002. There was a net loss of about 110 Mm 3 of sediment from the lagoon, most of which (73 Mm 3, ca.70%) was in the earlier period. A significant amount was lost by dredging and direct disposal outside the system, either on land or at sea, and there was a net loss of 39 Mm 3 from the lagoon to the sea through the inlets, at an annual rate of 0.5 Mm 3. Comparison of erosion rates in the two periods revealed an alarming acceleration, from a net sediment loss of 0.3 Mm 3 yr -1 in the period 1927-1970 to 0.8 Mm 3 yr -1 in 1970-2002. Deterioration caused a shift from a