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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. [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. PMID:15264546

  3. 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.

  4. 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

    2016-01-01

    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.

  5. Mapping mangrove leaf area index at the species level using IKONOS and LAI-2000 sensors for the Agua Brava Lagoon, Mexican Pacific

    NASA Astrophysics Data System (ADS)

    Kovacs, John M.; Wang, Jinfei; Flores-Verdugo, Francisco

    2005-01-01

    Using both IKONOS and in situ LAI-2000 sensor data, a map of estimated LAI, based on NDVI, was created for the Agua Brava Lagoon, Mexican Pacific. The LAI values were then aggregated according to four classes; red mangrove ( Rhizophora mangle), healthy white mangrove ( Laguncularia racemosa), poor condition white mangrove and dead mangrove. Of the live mangrove, calculated at approximately 85% of the forest, mean LAI values of 2.49, 1.74 and 0.85 were determined for the red, healthy white and poor condition white mangrove, respectively. Excluding the dead areas, an overall estimated mangrove LAI value of 1.81 was ascertained for the 71 km 2 of mapped mangrove forest. Although the results do suggest the technique as a very rapid and effective method for monitoring the condition of mangroves at the species level, potential limitations are also discussed.

  6. 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. PMID:27070015

  7. 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.

  8. 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

  9. Flux of nitrogen and sediment in a fringe mangrove forest in terminos lagoon, Mexico

    NASA Astrophysics Data System (ADS)

    Rivera-Monroy, Victor H.; Day, John W.; Twilley, Robert R.; Vera-Herrera, Francisco; Coronado-Molina, Carlos

    Fluxes of dissolved inorganic and organic nitrogen, particulate nitrogen, and total suspended sediments were measured in a fringe mangrove forest using the flume technique during a 15-month period in Terminos Lagoon, Mexico. The 12-m flume extended through a fringe forest from a tidal creek to a basin forest. There was a net import of dissolved inorganic nitrogen (NH +4 and NO -2+NO -3) from the creek and basin forest, while particulate (PN) and dissolved organic nitrogen (DON) were exported to the creek and basin forest. The tidal creek was the principal source of NH +4 (0·53 g m -2 year -1) and NO -2+NO -3 (0·08 g m -2 year -1) to the fringe forest, while the basin forest was the main source of total suspended sediments (TSS; 210 g m -2 year -1). Net export of PN occurred from the fringe forest to the tidal creek (0·52 g m -2 year -1) while less PN was exported to the basin forest (0·06 g m -2 year -1). The decrease in salinity during the rainy season indicated that nutrient concentrations in the tidal creek may have been influenced by inputs from rainfall and river discharge to the lagoon. There was a net import of TSS to the fringe forest from both the creek and basin forests, but the net input was 3·5 times higher at the fringe/basin interface. Particulate material exported from the forest during ebb tides generally had a higher C/N ratio than particulate matter imported into the forest on the flooding tide. This suggested that there was a greater nitrogen demand during ebb tide caused by the export of nitrogen-deficient detritus from fringe and basin mangroves. The exchange of nutrients among the tidal creek, the fringe, and basin forests in Estero Pargo is strongly influenced by seasonal weather forcing, such as winter storms, that can influence the magnitude and direction of water flow. The net annual import of inorganic nitrogen and the export of DON and PN suggest, in contrast to other mangrove systems, that the fringe mangrove forest in Estero Pargo

  10. 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.

  11. 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.

  12. 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. PMID:21414637

  13. 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.

  14. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. 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

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

    PubMed

    Ravva, Subbarao V; Sarreal, Chester Z

    2014-11-01

    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

  18. 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.

  19. 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.

  20. 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…

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. [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

  6. [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

  7. 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.

  8. Effect of mangrove detrital outwelling on nutrient regeneration and oxygen fluxes in coastal sediments of the central Great Barrier Reef lagoon

    NASA Astrophysics Data System (ADS)

    Alongi, Daniel M.

    1990-11-01

    The effect of tidal outwelling of mangrove detritus on sediment nutrient chemistry, nutrient regeneration and oxygen fluxes in a coastal area of the central Great Barrier Reef lagoon was examined. Organic carbon and total nitrogen concentrations ranged from 0·2 to 3·9% and 0·01 to 0·18% by sediment dry weight (DW), respectively, and were highest at stations receiving the greatest quantities of mangrove litter. Total phosphorus concentrations ranged from 0·013 to 0·048% by DW, but did not relate to outwelling. C:N:P. ratios ranged from 29:6:1 at the site receiving the least amount of detritus to a high of 397:17:1 at the station receiving the most litter. The effect of outwelling on dissolved inorganic nutrients in porewaters was less clear, with concentrations closely related to sediment type and obscured by contributions from continental runoff. Ammonium (range: 10-310 μM) and silicate (range: 10-315 μM) were in greatest concentration at most sites followed by phosphate (range: 1-12 μM) and nitrite and nitrate (0·07-6·0 μM). Directly measured fluxes of dissolved inorganic nutrients across the sediment-water interface were either undetectable or small [ΣN = -560 to +3503; PO 43 = undetectable to +157; Si(OH) 4 = undetectable to +6449 μmol m -2 day -1] and not related to outwelling. Addition of mangrove litter to ☐core samples incubated for 10 days in the laboratory did not affect rates of dissolved inorganic nutrient release. Oxygen consumption rates ranged from 8·7 to 60·2 mmol O 2 m -2 day -1 and were highest at most sites closest to mangrove forests, in agreement with previous measurements of bacterial productivity. Rates of net community primary production were either undetectable or low (as were chlorophyll α and phaeopigments) ranging from 12 to 77 mg C m -2 day -1. It appears that much of the deposited mangrove litter is highly refractory, but the amount of sedimented material appears to be great enough to significantly enrich bulk

  9. 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.

  10. [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. PMID:21302531

  11. 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.

  12. Economics: Mangroves' hidden value

    NASA Astrophysics Data System (ADS)

    Murray, Brian C.

    2012-11-01

    Mangroves are being lost at an alarming rate as their conversion for aquaculture and other uses is profitable. Research, however, suggests that valuing the deep reserves of carbon in mangrove sediments may be the key to their survival.

  13. 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. PMID:10730307

  14. Extractable Organic Components and Nutrients in Wastewater from Dairy Lagoons Influence the Growth and Survival of Escherichia coli 0157:H7

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of nutrients in wastewater from dairy lagoons on the survival of Escherichia. coli O157:H7 was monitored. Initially, the survival of E. coli in wastewater was compared with or without removing the competing native organisms by filter-sterilization or autoclaving. E. coli declined rapid...

  15. 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.

  16. 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.

  17. Chronic toxicity bioassay and effect of endosulfan, HCH, copper and zinc on the survival and intermoult duration of larvae of mangrove crab Macrophthalmus erato De Man.

    PubMed

    Kannupandi, T; Pasupathi, K; Soundarapandian, P

    2001-08-01

    The effects of insecticides (endosulfan, HCH) and heavy metals (copper and zinc) were studied on survival and duration of the moult cycle of larvae and megalopa of a common mangrove crab, Macrophthalmus erato, that inhabits Pitchavaram mangroves, southeast coast of India. In chronic toxicity test, percentage of survival from hatchling to megalopa stage at different concentrations of endosulfan (0.048 to 0.36 microg/L), HCH (0.32 to 2.4 microg/L), copper (9.0 to 67.5 microg/L) and zinc (15.2 to 139.0 microg/L) were 6, 12, 8 and 12 respectively. Endosulfan, HCH, copper and zinc considerably increased the total period in development from first zoea to megalopa stage from 18 days in the control to 23, 21, 20 and 22 days in the treated specimens. It is concluded that concentrations well below the observed chronic concentrations, may prove to be more deleterious to larva of this species in natural environment leading to reduction in the success of recruitment to the adult population. PMID:12018587

  18. 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

  19. Environmental Physiology of the Mangrove Rivulus, Kryptolebias marmoratus, A Cutaneously Breathing Fish That Survives for Weeks Out of Water

    PubMed Central

    Wright, Patricia A.

    2012-01-01

    The mangrove rivulus (Kryptolebias marmoratus) is an excellent model species for understanding the physiological mechanisms that fish use in coping with extreme environmental conditions, particularly cutaneous exchange during prolonged exposure to air. Their ability to self-fertilize and produce highly homozygous lineages provides the potential for examining environmental influences on structures and related functions without the complications of genetic variation. Over the past 10 years or so, we have gained a broader understanding of the mechanisms K. marmoratus use to maintain homeostasis when out of water for days to weeks. Gaseous exchange occurs across the skin, as dramatic remodeling of the gill reduces its effective surface area for exchange. Ionoregulation and osmoregulation are maintained in air by exchanging Na+, Cl−, and H2O across skin that contains a rich population of ionocytes. Ammonia excretion occurs in part by cutaneous NH3 volatilization facilitated by ammonia transporters on the surface of the epidermis. Finally, new evidence indicates that cutaneous angiogenesis occurs when K. marmoratus are emersed for a week, suggesting a higher rate of blood flow to surface vessels. Taken together, these and other findings demonstrate that the skin of K. marmoratus takes on all the major functions attributed to fish gills, allowing them to move between aquatic and terrestrial environments with ease. Future studies should focus on variation in response to environmental changes between homozygous lineages to identify the genetic underpinnings of physiological responses. PMID:22693260

  20. 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.

  1. 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.

  2. 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. PMID:25993360

  3. 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.

  4. 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

  5. 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

  6. 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

  7. Mangrove health in an arid environment encroached by urban development--a case study.

    PubMed

    Holguin, Gina; Gonzalez-Zamorano, Patricia; de-Bashan, Luz E; Mendoza, Renato; Amador, Edgar; Bashan, Yoav

    2006-06-15

    Urban development will soon encroach upon several protected and largely unspoiled arid climate mangroves ecosystems located along the lagoon called Ensenada de La Paz in Baja California Sur, Mexico. Many of these mangroves are located on a large sandbar that separates the lagoon on the south side from Bahía de La Paz to the north. A general evaluation of the current status of these mangroves was conducted to establish biological and physicochemical indicators of the health of these mangroves to serve as a natural or predevelopment baseline in future management. The following parameters were measured in the feeding channels of the mangroves and at the mouth of the channels: vegetation coverage, species and health, and levels of dissolved oxygen, pH, salinity, total nitrogen, ammonium, nitrates and nitrites, phosphorus ions, and organic matter in sediments and seawater. The microbiological elements that were studied included aerobic bacteria, N2-fixing bacteria, inorganic phosphate solubilizers, coliform, and phytoplankton diversity. Bird populations were counted, with special attention to migratory and resident birds and protected and endangered species. A comprehensive analysis of all the elements indicated that the health of the sandbar mangrove populations is good despite the proximity of a modest urban center. It also demonstrated that several biological and physicochemical parameters used in this study, including the birds, can serve as indicators of mangrove health and as a baseline for future management of mangroves in regions with arid climates.

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. Nutrition of mangroves.

    PubMed

    Reef, Ruth; Feller, Ilka C; Lovelock, Catherine E

    2010-09-01

    Mangrove forests dominate the world's tropical and subtropical coastlines. Similar to other plant communities, nutrient availability is one of the major factors influencing mangrove forest structure and productivity. Many mangrove soils have extremely low nutrient availability, although nutrient availability can vary greatly among and within mangrove forests. Nutrient-conserving processes in mangroves are well developed and include evergreeness, resorption of nutrients prior to leaf fall, the immobilization of nutrients in leaf litter during decomposition, high root/shoot ratios and the repeated use of old root channels. Both nitrogen-use efficiency and nutrient resorption efficiencies in mangroves are amongst the highest recorded for angiosperms. A complex range of interacting abiotic and biotic factors controls the availability of nutrients to mangrove trees, and mangroves are characteristically plastic in their ability to opportunistically utilize nutrients when these become available. Nitrogen and phosphorus have been implicated as the nutrients most likely to limit growth in mangroves. Ammonium is the primary form of nitrogen in mangrove soils, in part as a result of anoxic soil conditions, and tree growth is supported mainly by ammonium uptake. Nutrient enrichment is a major threat to marine ecosystems. Although mangroves have been proposed to protect the marine environment from land-derived nutrient pollution, nutrient enrichment can have negative consequences for mangrove forests and their capacity for retention of nutrients may be limited.

  13. 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)

  14. 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.

  15. 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

  16. 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

  17. 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 ...

  18. 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)

  19. 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.

  20. 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.

  1. 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. PMID:24751377

  2. 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.

  3. 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

  4. 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. PMID:27100002

  5. 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.

  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. 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.

  8. 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.

  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. 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

  11. 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. PMID:21141670

  12. 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.

  13. Biomass, litterfall and decomposition rates for the fringed rhizophora mangle forest lining the Bon Accord Lagoon, Tobago.

    PubMed

    Juman, Rahanna A

    2005-05-01

    The mangrove forest that fringes the Bon Accord Lagoon measures 0.8 km(2) and is dominated by red mangrove (Rhizophora mangle). This forest forms the landward boundary of the Buccoo Reef Marine Park in Southwest Tobago, and is part of a mangrove-seagrass-coral reef continuum. Biomass and productivity, as indicated by litterfall rates, were measured in seven 0.01 ha monospecific plots from February 1998 to February 1999, and decomposition rates were determined. Red mangrove above-ground biomass ranged between 2.0 and 25.9 kg (dry wt.) m(-2). Mean biomass was 14.1+/-8.1 kg (dry wt.) m(-2) yielding a standing crop of 11 318+/-6 488 t. Litterfall rate varied spatially and seasonally. It peaked from May to August (4.2-4.3 g dry wt. m(-2) d(-1)) and was lowest from October to December (2.3-2.8 g dry wt. m(-2) d(-1)). Mean annual litterfall rate was 3.4+/-0.9 g dry wt. m(-2) d(-1). Leaf degradation rates ranged from 0.3% loss d(-1) in the upper intertidal zone to 1% loss d(-1) at a lower intertidal site flooded by sewage effluent. Mean degradation rate was 0.4+/-1% loss d(-1) . The swamp produces 2.8 t dry wt. of litterfall and 12 kg dry wt. of decomposed leaf material daily. Biomass and litterfall rates in Bon Accord Lagoon were compared to five similar sites that also participate in the Caribbean Coastal Marine Productivity Programme (CARICOMP). The Bon Accord Lagoon mangrove swamp is a highly productive fringed-forest that contributes to the overall productivity of the mangrove-seagrass-reef complex. PMID:17465160

  14. 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)

  15. 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,…

  16. 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.

  17. 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. PMID:18686501

  18. 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. PMID:18494299

  19. 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.

  20. 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)

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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. PMID:21302409

  7. 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

  8. 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.

  9. 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

  10. 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

  11. The response of mangroves to projected impacts of global climate change

    SciTech Connect

    Twilley, R.R.; Chen, R.H.

    1995-06-01

    A hierarchical classification system for mangroves together with a community-based ecological model (ESA abstract by Chen and Twilley, 1995) were used to asses the response of mangroves to global climate change. The hierarchical classification includes a matrix of the ecological type (riverine, fringe, basin, and dwarf mangroves) and the geomorphologic environmental setting (delta, estuarine, lagoon, carbonate platform systems). The significance of this hierarchical classification, referred to as a eco-geomorphic system, is demonstrated with a summary of the spatial variation in ecosystem function among different coastal settings. Changes in sea level, frequency of frost, and frequency of hurricanes were simulated and results of forest community composition, tree density and dominance, and forest biomass were compared to field sites of known disturbance. For lagoon basin forests, hurricane frequency increase from 28 yrs to 15 yrs had less impact on total biomass than increase in frost from 12 yrs to 8 yrs. Both disturbances changed the community composition of the forests. The patterns of recovery vary among geomorphic types due to nutrient limitation of regrowth.

  12. 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

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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

  19. 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.

  20. Belowground Dynamics in Mangrove Ecosystems

    USGS Publications Warehouse

    McKee, Karen L.

    2004-01-01

    MANGROVE ECOSYSTEMS 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.

  1. 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.

  2. 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

  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. 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

  5. Bellechester, Minnesota, USA, lagoon collapses

    NASA Astrophysics Data System (ADS)

    Alexander, E. C.; Broberg, J. S.; Kehren, A. R.; Graziani, M. M.; Turri, W. L.

    1993-12-01

    Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×106 1 of partially treated effluent and about 600 m3 of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials

  6. Decadal stability of Red Sea mangroves

    NASA Astrophysics Data System (ADS)

    Almahasheer, Hanan; Aljowair, Abdulaziz; Duarte, Carlos M.; Irigoien, Xabier

    2016-02-01

    Across the Earth, mangroves play an important role in coastal protection, both as nurseries and carbon sinks. However, due to various human and environmental impacts, the coverage of mangroves is declining on a global scale. The Red Sea is in the northern-most area of the distribution range of mangroves. Little is known about the surface covered by mangroves at this northern limit or about the changes experienced by Red Sea mangroves. We sought to study changes in the coverage of Red Sea mangroves by using multi-temporal Landsat data (1972, 2000 and 2013). Interestingly, our results show that there has been no decline in mangrove stands in the Red Sea but rather a slight increase. The area covered by mangroves is about 69 Km2 along the African shore and 51 Km2 along the Arabian Peninsula shore. From 1972 to 2013, the area covered by mangroves increased by about 0.29% y-1. We conclude that the trend exhibited by Red Sea mangroves departs from the general global decline of mangroves. Along the Red Sea, mangroves expanded by 12% over the 41 years from 1972 to 2013. Losses to Red Sea mangroves, mostly due to coastal development, have been compensated by afforestation projects.

  7. 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.

  8. Tsunami damage reduction performance of a mangrove forest in Banda Aceh, Indonesia inferred from field data and a numerical model

    NASA Astrophysics Data System (ADS)

    Yanagisawa, H.; Koshimura, S.; Miyagi, T.; Imamura, F.

    2010-06-01

    Since the 26 December 2004 Indian Ocean tsunami, the role of mangrove forests as natural defenses protecting coastal communities from tsunami disaster has been highlighted. However, some mangrove forests were destroyed by that tsunami. They are expected to have lost their protective functions. In this study, we develop a fragility function to assess the mangrove trees' vulnerability, expressed as the damage probability of mangrove trees, based on field surveys and numerical modeling of the 2004 Indian Ocean tsunami in Banda Aceh, Indonesia. Based on the fragility function, we reconstruct a numerical model of tsunami inundation including the performance of mangrove forests in terms of reducing tsunami damage. The model reveals that a 10 year old mangrove forest in a 500 m wide area can reduce a tsunami's hydrodynamic force by approximately 70% for an incident wave of 3.0 m inundation depth and a wave period of 40 min at the shoreline. The model also shows, for a tsunami inundation depth of greater than 4 m, that a 10 year old mangrove forest would be mostly destroyed and that it would lose its force reduction capacity. Moreover, approximately 80% of a 30 year old mangrove forest would survive a 5 m tsunami and absorb 50% of the tsunami's hydrodynamic force.

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Taxonomic diversity and structure of benthic macroinvertebrates in Aby Lagoon (Ivory Coast, West Africa).

    PubMed

    Kouadio, K N; Diomandé, D; Ouattara, A; Koné, Y J M; Gourène, G

    2008-09-15

    The benthic macroinvertebrates of Aby lagoon (West Africa: Ivory coast) was studied during four seasons (high dry season, high rainy season, low dry season and low rainy season, respectively) from June 2006 to March 2007. The distribution of the benthic macroinvertebrates species was recorded at 13 stations on the whole of the lagoon. A total of 62 taxa of benthic macroinvertebrates belonging to 28 families and 10 orders were listed. The molluscs and crustaceans dominate qualitatively by adding up 51 and 24%, respectively of the total number of organisms. Five taxa (Corbula trigona (20%), Pachymelania aurita (12%), Clibernhardius cooki (7%), Oligochaeta (7%) and Crassostrea gasar (6%) accounted for 52% of total abundance. Classification analysis used to perform the characterisation of the lagoon on the basis of benthic macroinvertebrates showed the existence of four main clusters in which the seasonal pattern in benthic macroinvertebrates were very similar in the four seasons. In contrast the species richness and diversity indices were significantly different. Furthermore these indices where higher in the stations closer to the sea and surrounded by mangrove trees (southern area) compared to the inland ones.

  16. 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

  17. Isopod and insect root borers may benefit Florida mangroves.

    PubMed

    Simberloff, D; Brown, B J; Lowrie, S

    1978-08-18

    Far from threatening the persistence and geographic extent of red mangrove (Rhizophora mangle) in Florida, wood-boring marine isopods may aid the plant to survive wave action by initiating branching of aerial prop roots. Evidence for a recent, sudden increase in density or range of one such isopod, Sphaeroma terebrans, is anecdotal and weak. Insect damage to mangrove aerial roots even before they descend to the water is at least as great as that wrought by isopods and also causes root branching. Aerial and submarine damage combine to stimulate root initiation so that, for every root produced aerially by the tree, at least 1.4 roots reach the substrate. Similar responses to herbivory, which have been reported for other plants, suggest that herbivores may both benefit and harm plants, and that their impact may be more difficult to assess in specific instances than has been realized.

  18. 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.

  19. Chlorophyll-deficient propagules of Avicennia marina and apparent longer term deterioration of mangrove fitness in oil-polluted sediments.

    PubMed

    Duke, Norman C; Watkinson, Andrew J

    2002-11-01

    A correlation between petroleum hydrocarbon concentrations in sediments and chlorophyll-deficient mutations in mangroves may occur also in Australian mangroves. Earlier reports of such mutations in the Caribbean area were evident in viviparous propagules of the common mangrove genera, Rhizophora, borne on otherwise normal trees. These mutant propagules were termed albinos' since they lacked chlorophyll and normal green coloration, leaving them white, yellow or red. The mutation was considered lethal since newly established albino seedlings appeared unable to survive more than a few months. Our preliminary investigation of mangroves in SE Queensland found a similar mutation in another common mangrove genus, Avicennia, and this was apparently also correlated with oil concentrations in sediments. Although, more evidence is required, an apparently similar relationship shows that whatever caused the mutations may act commonly across a diverse range of plant types in quite separate locations. How widespread might this mutation be in mangroves? How many genera and species are affected? Are all occurrences correlated with oil in sediments? Does oil cause the mutation? We discuss these important questions and the potentially serious implications to coastal management where high mutant densities may be indicative of longer term genetic deterioration of mangrove habitat in oil-polluted wetland environments. PMID:12523526

  20. 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.

  1. 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. PMID:23907934

  2. 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)…

  3. 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.

  4. Seed predation by insects in tropical mangrove forests: extent and effects on seed viability and the growth of seedlings.

    PubMed

    Robertson, A I; Giddins, R; Smith, T J

    1990-06-01

    Although insects are known to be important seed predators in most terrestrial forests, their role in marine tidal (mangrove) forests has not been examined. Surveys at 12 sites in tropical Australia showed that between 3.1 and 92.7 percent of the seeds or propagules of 12 mangrove tree species had been attacked by insects. Seeds/propagules of six species (Avicennia marina, Bruguiera gymnorrhiza, B. parviflora, Heritiera littoralis, Xylocarpus australasicus and X. granatum) showed consistently high (>40%) levels of insect damage. Greater than 99% of H. littoralis seeds were attacked by insect predators. The survival and subsequent growth in height and biomass of insect-damaged and non-damaged control seeds/propagules of eight mangrove species were compared in shadehouse experiments. Mangrove species fell into 4 groups with regard to the effect of insect predators on their seeds and seedlings. Xylocarpus australasicus and X. granatum had significantly decreased survival (X 48 and 70%) and growth in height (X 61 and 96%) and biomass (X 66 and 85%). Bruguiera parviflora showed decreased survival (X 59%), but there was no effect of insects on the growth of surviving propagules. In contrast, there was no effect of insect damage on the survival of seedlings of Avicennia marina and Bruguiera exaristata, but decreased growth in height (X 22 and 25%) and biomass (X 22 and 26%). Survival and growth of seedlings of Rhizophora stylosa and Bruguiera gymnorrhiza were not affected. The influence of insect seed predators on the survival and growth of seeds of mangrove species in forests will depend on the relative abundance of seed-eating crabs and intertidal position in mangrove forests. PMID:22160114

  5. 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. PMID:16151655

  6. 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.

  7. 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.

  8. 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

  9. Tracer studies on an aerated lagoon.

    PubMed

    Broughton, Alistair; Shilton, Andy

    2012-01-01

    The city of Palmerston North, New Zealand, has two aerated lagoons as its secondary treatment facility. Interest about treatment efficiency led to an investigation into the hydraulics in the second lagoon to determine if further optimisation was viable. A tracer study using rhodamine WT was undertaken to ascertain the stimulus response output. Samples were also taken at 24 points within the lagoon to determine the tracer concentration profile throughout the lagoon. The mean residence time was determined to be 39.9 h compared with a theoretical residence time of 55.4 h. Peak concentration of the tracer at the outlet occurred at 0.44 of the mean residence time. The results of the tracer study pointed to 28% of volume being dead space. A subsequent sludge survey indicated that 26% of the design volume of the lagoon was filled with sludge. While the curved geometry of the lagoon did not appear to impact the hydraulics the fact that the first aerator is confined in a relatively smaller area will have locally boosted the mixing energy input in this inlet zone. From interpretation of the tracer response and the tracer distribution profiles it appears that the aerators are mixing the influent into the bulk flow effectively in the front end of the lagoon and that there was no evidence of any substantive short-circuiting path of concentrated tracer around to the outlet. The tracer distribution profiles gave direct insight as to how the tracer was being transported within the pond and should be used more often when conducting tracer studies. Comparison with the literature indicated that the lagoon's hydraulic efficiency was on par with a baffled pond system and it would be expected that addition of several baffles to the lagoon would provide minimal further improvement. PMID:22277219

  10. 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.

  11. 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

  12. Modifications in Coverage Patterns and Land Use around the Huizache-Caimanero Lagoon System, Sinaloa, Mexico: A Multi-temporal Analysis using LANDSAT Images

    NASA Astrophysics Data System (ADS)

    Ruiz-Luna, A.; Berlanga-Robles, C. A.

    1999-07-01

    Human activities, such as agriculture and shrimp farming, have influenced the Huizache-Caimanero lagoon system, modifying the landscape and diminishing its natural productivity. Four Landsat MSS (multi-spectral scanner) and TM (thematic mapper) sub-images, taken between 1973 and 1997, were analysed to evaluate trends of changes in the lagoon, saltmarsh, mangrove, agriculture, secondary succession and dry forest classes. The scenes were enhanced by principal components analysis. A thematic map for each sub-image was produced using supervised classification with the extraction and classification of homogeneous objects algorithm (ECHO). Aerial photography and field verification of testing points were used to validate the classification and to assess its accuracy using the Kappa coefficient. The area covered by class and year was estimated and the temporal trends were defined by linear regression. The natural covers (lagoon, mangrove and dry forest) showed a significant reduction in 1997 when compared with 1973, whereas the agricultural areas, secondary succession and saltmarshes showed an increase in cover. The frequency distribution analysis of the normalized difference vegetation index (NDVI) confirmed the observed trends. The Huizache-Caimanero region is a highly disturbed landscape, mainly caused by agricultural practices, that must be rehabilitated to maintain its natural productivity.

  13. 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.

  14. 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.

  15. 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. PMID:27427389

  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.

  17. Coastal mangrove forests mitigated tsunami

    NASA Astrophysics Data System (ADS)

    Kathiresan, Kandasamy; Rajendran, Narayanasamy

    2005-11-01

    A study conducted after the 26th of December 2004 tsunami in 18 coastal hamlets along the south-east coast of India reiterates the importance of coastal mangrove vegetations and location characteristics of human inhabitation to protect lives and wealth from the fury of tsunami. The tsunami caused human death and loss of wealth and these decreased with the area of coastal vegetation, distance and elevation of human inhabitation from the sea. Human inhabitation should be encouraged more than 1 km from the shoreline in elevated places, behind dense mangroves and or other coastal vegetation. Some plant species, suitable to grow in between human inhabitation and the sea for coastal protection, are suggested.

  18. 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.

  19. Seagrass-sediment feedbacks in shallow coastal lagoons

    NASA Astrophysics Data System (ADS)

    Carr, J. A.; D'Odorico, P.; McGlathery, K.; Wiberg, P.

    2009-12-01

    Shallow coastal lagoons are environments where a delicate equilibrium exists between water quality and sea grass cover. Seagrass cover limits the resuspension of bed sediments thereby favoring a clearer water column. These conditions allow for the penetration of adequate levels of light, which in turn, is fundamental for the survival of seagrass. It is still unclear what role this positive feedback may play in the dynamics and restoration of seagrass communities. Positive feedbacks are often associated with the existence of bistable dynamics in ecosystems. In this specific case a bare and a fully vegetated sediment bed could be both stable states of the system. This study develops a one dimensional hydrodynamic model of vegetation-sediment-water flow interactions to investigate the strengths of positive feedbacks between sea grass cover, stabilization of bed sediments, turbidity of the water column, and the existence of a favorable light environment for seagrasses. The model is applied to Hog Island Bay, a shallow coastal lagoon on the eastern shore of Virginia. The effects of temperature, eutrophication, and bed grain size on bistability of seagrass ecosystems in the lagoon are explored. The results indicate that under typical conditions, seagrass is stable in water depths < 2.2 m (51% of the bay bottom deep enough for seagrass growth) and bistable conditions exist for depths of 2.2 - 3.6 m (23% of bay) where the preferred state depends in initial seagrass cover. The remaining 26% of the bay is too deep to sustain seagrass. Decreases in sediment size and increases in water temperature and degree of eutrophication shift the bistable range to shallower depths, with more of the bay bottom unable to sustain seagrass.

  20. Rhodoliths and coralliths of Muri Lagoon, Rarotonga, Cook Islands

    NASA Astrophysics Data System (ADS)

    Scoffin, Terence P.; Stoddart, David R.; Tudhope, Alexander W.; Woodroffe, Colin

    1985-09-01

    Free-living massive and branching spheroidal growths (about 5 cm diameter) of calcareous red algae (rhodoliths) and corals (coralliths) occur in abundance on the sea bed of shallow Muri Lagoon on Rarotonga's reef flat. The rhodoliths are composed of one or more species of Neogoniolithon, Lithophyllum, Tenarea, and Porolithon; the coralliths are Pavona varians (Verrill) and Porites lutea (Milne-Edwards and Haime). Muri Lagoon is the only area on Rarotonga's reef flat that is sheltered by reef islands from ocean waves. The tidal currents, which are predominantly unidirectional in Muri Lagoon, are concentrated by the reef islands into channels through which sand and gravel sediment is regularly transported. However, these prevailing currents do not normally roll the rhodoliths and coralliths. The results of field experiments on the pick-up velocity of the various types of spheroidal structure, combined with observations on growth histories of massive coralliths as revealed by the non-concentric nature of skeletal density banding, indicate that the rhodoliths and coralliths may remain static for periods up to several months yet maintain a complete envelope of living tissue. This downward survival may depend on the strong currents. Not only is the water flushing through the upper millimetre or so of the sediment substrate, but it is also capable of moving the sand and gravel grains which laterally support the rhodoliths and coralliths so that no one point of a spheroidal structure is in direct contact with the substrate for a fatal length of time. Massive rhodoliths have a high preservation potential as discrete spheroidal structures; in contrast, branching rhodoliths and coralliths are prone to fragmentation, and massive coralliths grow into stable microatolls. We conclude that a similar assemblage of rhodoliths, coralliths and microatolls in the fossil record may be indicative of the former existence of contemporary reef flat islands.

  1. [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.

  2. 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

  3. 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.

  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. Inactivation kinetics of Cryptosporidium parvum oocysts in a swine waste lagoon and spray field.

    PubMed

    Jenkins, Michael B; Liotta, Janice L; Bowman, Dwight D

    2013-04-01

    Because of outbreaks of cryptosporidiosis in humans, some Cryptosporidium spp. have become a public health concern. Commercial swine operations can be a source of this protozoan parasite. Although the species distribution of Cryptosporidium is likely dominated by Cryptosporidium suis , a fraction may be comprised of other Cryptosporidium species infectious to humans such as Cryptosporidium parvum . To better understand the survival dynamics of Cryptosporidium spp., oocysts associated with swine operations, 2 experiments were performed to determine die-off rates of C. parvum oocysts in a swine waste lagoon (2009 and 2010) and its spray field (2010 and 2011). Sentinel chambers containing a lagoon effluent suspension of C. parvum oocysts were submerged in the lagoon, and triplicate chambers were removed over time; oocysts were extracted and assayed for viability. For comparative purposes, inactivation rates of Ascaris suum eggs contained in sentinel chambers were also determined. For 2 spray field experiments, air-dried and sieved surface soil was placed in sentinel chambers, hydrated, and inoculated with a lagoon effluent suspension of C. parvum oocysts. Sentinel chambers and control oocysts in PBS contained in microcentrifuge tubes were buried 1.5 cm below the soil surface in 3 blocks. Triplicate chambers and controls were removed over time; oocysts were extracted and assayed for viability. Based on the first order decay equation, days to reach 99% die-off (T(99)) were determined. T(99)-values determined for the 2 lagoon experiments were 13.1 and 20.1 wk, respectively. A T(99)-value for C. parvum in the spray field was significantly longer at 38.0 wk than the control oocysts in PBS at 29.0 wk. The waste lagoon and spray field system of manure management at this large-scale farrowing operation appeared to reduce the load of C. parvum oocysts before they can be hydrologically transported off the operation and reduces their likelihood of contaminating surface waters

  6. 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). PMID:27245554

  7. 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).

  8. [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. PMID:22803457

  9. [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.

  10. [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. PMID:19928448

  11. 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.

  12. 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.

  13. The Patos Lagoon summertime circulation and dynamics

    NASA Astrophysics Data System (ADS)

    Moller, Osmar O.; Lorenzzentti, Joa˜o. A.; Stech, JoséL.; Math, Mauricio M.

    1996-03-01

    The main aspects of the summertime circulation and dynamics of the Patos Lagoon, a system located in southern Brazil and considered as one of the world's largest choked coastal lagoons, are studied through the analysis of time series of wind stress, water level and freshwater discharge, combined with the results of a barotropic circulation model. The longitudinal wind component has been verified as the main driving force, generating a set-up/set-down mechanism of oscillation with the nodal line in the midlagoon area. The period of this oscillation coincides with the passages of frontal systems for this region. The sea breeze acts as a secondary effect, being clearly observed in the northern part of the lagoon. Freshwater discharge is expected to cause variations in water level on the seasonal band and to a lesser degree in the 8-15 day time-scale. The tidal signal is of importance only near the exit to the ocean, being strongly reduced in the interior of the lagoon. Model results suggest a wind set-up momentum balance in the longitudinal direction in the deeper parts of the lagoon; near the margins, the longitudinal momentum balance is mostly of frictional form, with the wind stress being balanced by the bottom friction. In the lateral direction, a geostrophic balance is verified in both regions. The wind forced circulation is characterized by the presence of several cells with downwind velocity near the margins and upwind return flow occurring in the central areas.

  14. 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.

  15. Inverse-dispersion technique for assessing lagoon gas emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. 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 ...

  17. 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,…

  18. Salinity dependence of the distribution of multicellular magnetotactic prokaryotes in a hypersaline lagoon.

    PubMed

    Martins, Juliana L; Silveira, Thaís S; Silva, Karen T; Lins, Ulysses

    2009-09-01

    Candidatus Magnetoglobus multicellularis is an unusual magnetotactic multicellular microorganism composed of a highly organized assemblage of gram-negative bacterial cells. In this work, the salinity dependence of Ca. M. multicellularis and its abundance in the hypersaline Araruama Lagoon, Brazil were studied. Viability experiments showed that Ca. M. multicellularis died in salinities upper than 55 per thousand and lower than 40 per thousand. Low salinities were also observed to modify the cellular assemblage. In microcosms prepared with different salinities, the microorganism grew better at intermediate salinities whereas in high or low salinities, the size of the population did not increase over time. The concentrations of Ca. M. multicellularis in the lagoon were related to salinity; sites with lower and higher salinities than the lagoon average contained less Ca. M. multicellularis. These results demonstrate the influence of salinity on the survival and distribution of Ca. M. multicellularis in the environment. In sediments, the abundance of Ca. M. multicellularis ranged from 0 to 103 microorganisms/ml, which represented 0.001% of the counts of total bacteria. The ability of Ca. M. multicellularis to accumulate iron and sulfur in high numbers of magnetosomes (up to 905 per microorganism) suggests that its impact on the sequestration of these elements (0.1% for biogenic bacterial iron) is not proportional to its abundance in the lagoon.

  19. 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. PMID:20857193

  20. 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. PMID:26706768

  1. 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.

  2. How to alleviate degradation of mangroves?

    PubMed

    Kathiresan, K

    2004-10-01

    This work has experimentally proved that hyper salinity, a major cause for degradation of coastal mangrove habitats, can be alleviated by flushing of hyper saline soil with tidal water and/or with rainwater. Over a period of three years after digging the creeks to flush hyper saline soil with tidal water, an appreciable reduction in soil salinity and a moderate increase in colonization of mangroves are observed. Soil analysis showed a significant reduction in salinity after 2 months of storage of rainwater with a significant and concomitant increase of heterotrophic bacterial counts and nutrients. This study raises the possibility of converting degrading mangrove habitats to luxuriant ones through man-made efforts.

  3. 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

    2010-01-01

    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

  4. 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

  5. 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. PMID:26267403

  6. Evolutionary diversity among Atlantic coast mangroves

    NASA Astrophysics Data System (ADS)

    Dodd, Richard S.; Rafii, Zara A.; Fromard, François; Blasco, François

    1998-06-01

    Current knowledge of intraspecific variation of mangrove species is limited in terms of rangewide distributions and is mostly restricted to morphological analyses, which have indicated a high degree of homogeneity. However, our analyses of the aliphatic hydrocarbon and triterpenoid fraction of foliar waxes (by gas chromatography and mass spectroscopy) of mangrove species ( Rhizophora mangle, Avicennia germinans and Laguncularia racemosa) from Gabon in West Africa and French Guiana in South America show significant genetic differentiation between eastern and western Atlantic provenances. The greater diversity in lipid composition, and the tendency for longer carbon chain lengths in all taxa from Africa, may suggest that American mangroves exhibit derived characteristics. A consequence of this hypothesis would be that Atlantic mangroves are unlikely to have dispersed from the Tethys via the Pacific, as has been proposed by some authors. More widespread sampling within the Atlantic and east Pacific region is needed to support and confirm these results.

  7. Exploring new issues for coastal lagoons monitoring and management

    NASA Astrophysics Data System (ADS)

    Gaertner-Mazouni, Nabila; De Wit, Rutger

    2012-12-01

    Coastal lagoons are productive and highly vulnerable ecosystems, but their management is still problematic mostly because they constitute transitional interface between terrestrial and marine domains. The "4th European Conference on Coastal Lagoon Research - Research and Management for the conservation of coastal lagoon ecosystems, South North comparisons", was focused on the scientific research on coastal lagoons and the management for their conservation and sustainable use. Selected contributions were considered in this special issue of Estuarine Coastal and Shelf Science "Research and Management for the conservation of coastal lagoon ecosystems" as they deal with three important aspects for coastal lagoons management: (1) the design of monitoring programmes using biological compartments, (2) the ecosystem functioning and the impacts of perturbations and (3) ecosystem trajectories particularly after ecosystem restoration. Here we introduce the selected papers published in this issue, place these contributions in the perspective of the science-management interface and discuss new issues for coastal lagoon management.

  8. 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.

  9. 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.

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

    PubMed

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

    2010-04-12

    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

  11. 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. PMID:17439624

  12. Mercury Concentrations in Coastal Sediment from Younger Lagoon, Central California

    NASA Astrophysics Data System (ADS)

    Hohn, R. A.; Ganguli, P. M.; Swarzenski, P. W.; Richardson, C. M.; Merckling, J.; Johnson, C.; Flegal, A. R.

    2013-12-01

    Younger Lagoon Reserve, located in northern Monterey Bay, is one of the few relatively undisturbed wetlands that remain along the Central Coast of California. This lagoon system provides protected habitat for more than 100 bird species and for populations of fish, mammals, and invertebrates. Total mercury (HgT) concentrations in water within Younger Lagoon appear to vary with rainfall conditions and range from about 5-15 pM. These concentrations are similar to HgT in water from six nearby lagoon systems. However, Younger Lagoon contains elevated concentrations of dissolved organic carbon (~1 mM) and monomethylmercury (MMHg, ~1 pM) relative to our comparison lagoon sites (DOC < 0.5 mM and MMHg < 0.5 pM). We attribute Younger Lagoon's high DOC and MMHg to its restricted connection to the ocean and minor riverine contribution. Coastal lagoons in this region typically form at the mouth of streams. They behave as small estuaries during the wet season when surface water discharge keeps the mouth of the stream open to the ocean, and then transition into lagoons in the dry season when a sand berm develops and effectively cuts off surface water exchange. At Younger Lagoon, the sand berm remains intact throughout the year, breaching only during particularly high tides or intense rain events. Therefore, the lagoon's connection to nearshore seawater is primarily via surface water - groundwater interaction through the sand berm. Because Younger Lagoon is largely isolated from a surface water connection with the ocean, runoff from upgradient urban and agricultural land has an enhanced impact on water (and presumably sediment) quality. As a result, the lagoon is eutrophic and experiences annual algal blooms. Groundwater surveys suggest surface water, groundwater, and coastal seawater are hydraulically connected at Younger Lagoon, and mixing among these water masses appears to influence water geochemistry. To date, no chemical analyses have been conducted on sediment from Younger

  13. 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. PMID:25760867

  14. 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.

  15. 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

  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. 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.

  18. 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.

  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.

  20. 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).

  1. 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.

  2. 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.

  3. 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.

  4. Spatial and temporal variation of biomarkers in mussels (Mytilus galloprovincialis) from the Lagoon of Venice, Italy.

    PubMed

    Nesto, Nicoletta; Bertoldo, Martina; Nasci, Cristina; Da Ros, Luisa

    2004-01-01

    A multiple biomarker approach was adopted in a seasonal study carried out in the Lagoon of Venice, with the double aim of evaluating the natural and anthropic stresses influencing the biological responses of mussel (Mytilus galloprovincialis) and of assessing the effects due to spatial rather than temporal variations. Biochemical (aldehyde dehydrogenase and catalase activities), cellular (neutral red retention time) and physiological (survival in air and condition index) biomarkers were determined in mussels collected in four differently impacted lagoon areas. Multivariate analysis showed that samples were distributed mainly according to temperature and four seasonal groups were identified. The combination of spatial and temporal information enabled us to distinguish physiological variations due to natural causes from those due to anthropic stress, and to identify the sampling period when several biomarkers are less influenced by both natural and endogenous factors. PMID:15178046

  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. 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.

  7. Sphaeroma terebrans: A Threat to the Mangroves of Southwestern Florida.

    PubMed

    Rehm, A; Humm, H J

    1973-10-12

    Sphaeroma terebrans, a wood-boring isopod, is destroying the prop roots of red mangroves along the southwestern coast of Florida to such an extent that the Ten Thousand Islands and mangrove fringes of the mainland are steadily shrinking. Mangroves of the Florida Keys apparently are free of this wood borer.

  8. Natural products from true mangrove flora: source, chemistry and bioactivities.

    PubMed

    Wu, Jun; Xiao, Qiang; Xu, Jing; Li, Min-Yi; Pan, Jian-Yu; Yang, Mei-hua

    2008-10-01

    The mangrove flora is a diverse group of salt-tolerant plants growing in tropical and subtropical intertidal estuarine zones. This review summarizes the source, chemistry and bioactivities of natural products from true mangrove species worldwide. It includes 349 metabolites and 150 references. The molecular phylogeny and chemotaxonomy of true mangrove plants is discussed.

  9. [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. PMID:24027935

  10. 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. PMID:26084450

  11. 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.

  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. 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)

  14. [Research on mangrove soil microorganisms: past, present and future].

    PubMed

    Jiang, Yun-Xia; Zheng, Tian-Ling; Tian, Yun

    2006-10-01

    Special Mangrove soil niches possesses valuable microbial resources. Unfortunately, up to the present, so far there is very little knowledge on the mangrove soil microbial communities. It mainly due to the limitations of research methods. Cultureindependent approaches based on 16S rRNA, 18S rRNA gene analysis open the window to study microbial diversity in mangrove soil. The progress had achieved about studying on mangrove soil microbial species diversity, metabolic diversity and treating environmental pollutions was summarized in the paper. In addition, the bright future of mangrove soil microorganisms was described.

  15. Searching a Holocene coastal lagoon for paleotsunami deposits: Kamala Beach, Phuket, Thailand

    NASA Astrophysics Data System (ADS)

    Schmidt, J. R.; Kirby, M. E.; Rhodes, B. P.; Jankaew, K.

    2006-12-01

    In the wake of the devastating December 26, 2004 Indian Ocean tsunami, there is a renewed effort to locate and date paleotsunami deposits. As part of this effort, one piston and two push cores were extracted along a transect from a Holocene age coastal lagoon in Kamala Beach, Phuket, Thailand. The piston core (KBPISTON06-1 measures 513 cm total length. The overall sedimentology reflects a long-term sea level regression and beach progradation across the core site to the modern beach position. The sedimentology is, however, highly complex indicating variable depositional environments throughout the Holocene. Basal sands (estimated at 8,000 cy BP) are overlain by various thickness laminated clays, interbedded organic silts, and occasional sands. The upper 40 cm may reflect recent human disturbance, which includes mining of placer tin, planting of coconut trees, and tourist-related infrastructure. In addition to visual descriptions, mass magnetic susceptibility, percent total organic matter, and percent total carbonate were determined at 1 cm contiguous intervals. Micro-fossil counts and grain size measurements were also determined but at lower resolution throughout the core. Using visual description as the basic identifying criteria, we recognize four candidate deposits as potentially tsunamigenic. Each of the four units is sand-rich. Sandy clays bracket the upper two sand units; whereas, the lower two sand units are much coarser and bracketed by semi-to-well laminated clays. Considering each of the analyses above, we cannot identify any one of these candidate deposits as unequivocally tsunamigenic. Similarly, we cannot conclude that any one of these candidate deposits is not tsunamigenic. Nonetheless, our initial conclusion is that coastal lagoon environments may not represent the best location for preservation and identification of paleotsunami deposits in Thailand. Sites with less complex terrestrial-marine sediment interaction, such mangrove swamps, may be easier

  16. Organotin speciation in Bizerte lagoon (Tunisia).

    PubMed

    Mzoughi, N; Lespes, G; Bravo, M; Dachraoui, M; Potin-Gautier, M

    2005-10-15

    For the first time, organotins have been assessed in samples collected from Bizerte lagoon, in Tunisia, during two seasons (summer and winter). The organotin distribution was studied in marine sediments and mussels tissues of this lagoon. Butyl-, phenyl- and octyltins were determined using a rapid speciation analytical method based on one-step ethylation/extraction with sodium tetraethylborate in aqueous phase. Simultaneously to the ethylation, the extraction was performed by either liquid/liquid extraction (LLE) or head-space solid phase microextraction (HS-SPME). Gas chromatography with pulsed flame photometric detection (GC-PFPD) was used to perform quantitative determination. The technique has been validated using biological and sediment reference materials. The different samples from Bizerte lagoon were found to be moderately contaminated, especially by butyltins. This pollution was attributed to industrial activities, which are very important in this area. Organotins appeared accumulated in both sediments and mussels, while significant degradations of triorganotins to monosubstituted ones was observed in water. PMID:16198682

  17. 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.

  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.

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. Climatic Impact on Major and Trace Elements in Deltaic Core Sediments: Evidence from Muthupet Lagoon, se Coast of India

    NASA Astrophysics Data System (ADS)

    Jayaprakash, M.; Urban, B.; Murugan, P. M. V.; Dharan, L.; Seshachalam, S.; Jonathan, M.

    2013-12-01

    Geochemistry of lagoon deposits provides a continuous record of climatic changes, and such core sediments at successive deeper and older layers have long been utilized for sedimentologic and organic geochemical studies. These ecosystems present a mechanism for trapping sediment and therefore record climatic changes in the form of geochemical imprints. The aim of the present study is to evaluate the climatic and depositional controls in the Muthupet lagoon, situated at the southern most end of the Cauvery delta, south east India. The variations of geochemical parameters with depth and their ratios were employed to reveal the characteristics of Holocene climate and associated paleoenvironmental implications of this region. Moderate values of the Chemical Index of Alteration (CIA) suggest intermediate chemical weathering of the source rock under tropical to subtropical climatic conditions. Index of Composition Variability (ICV) values indicate low proportion of non clay silicate minerals in these sediments. V/Cr ratio has been used as a paleo-oxygenation indicator and in the present study, the ratio V/Cr was found to be < 2 indicating oxic-depositional conditions prevailing in this lagoon. Fe/Ti and Fe/Al ratios reveal valuable information on the impact of climate changes on the sedimentation in the study area. Na and S, indicators of paleosalinity and marine flooding were evaluated. The increase in concentration of Na at various depths was identified and marine incursions characterized. Abrupt changes in the values at certain depths were directly related to major climatic events using the available rainfall and 210Pb data. Key words: Climate change, Weathering Pattern, Muthupet Mangroves, SE coast of India. Location map of the study area

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

    SciTech Connect

    Bridger Morrison

    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.

  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. PMID:21887634

  10. 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...

  11. 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. PMID

  12. 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

  13. Seasonal hydrochemical variation in a tropical coastal lagoon (Açu Lagoon, Brazil).

    PubMed

    Chagas, G G; Suzuki, M S

    2005-11-01

    Hydrochemical conditions in the Açu Lagoon are described using spatial and temporal variations of various limnological variables (water temperature, dissolved oxygen, electric conductivity, total alkalinity, carbon dioxide, dissolved and total nutrients (N, P and Si), and chlorophyll a). Collected data was used in order to understand the structure and functioning of an enclosed coastal lagoon strongly influenced by climatic conditions. Water samples were collected monthly (November 1999-December 2000) in five sampling stations established along the lagoon. A decreasing spatial gradient of electrical conductivity was observed beginning from a sand bar region between the lagoon and the sea in the direction of the sweet-water input area. The positive correlation observed between the pH and dissolved oxygen (DO) values, and the negative one observed between pH values and those of carbon dioxide (CO2), evidenced coupled biological processes, e.g., primary production and decomposition. Both spatial and temporal variation of dissolved nutrients showed fast increase and decrease in the beginning of summer, suggesting that nutrient input resulting from rainfall stimulates phytoplankton production, as reflected by chlorophyll a concentration increase.

  14. 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

  15. 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. PMID:18645185

  16. [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.

  17. [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. PMID:23898678

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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…

  5. 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

  6. 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

  7. Discrimination of mangrove species in Matang Mangrove Forest Reserve, Perak using in-situ measurement of hyperspectral leaf reflectance

    NASA Astrophysics Data System (ADS)

    Chun, Beh Boon; Keat, Sim Chong; Syahreza, Saumi; Jafri, Mohd Zubir Mat; San, Lim Hwee

    2015-04-01

    Studies of mangrove species's reflectance characteristic are important in order to have a deep understanding of mangrove vegetation. In this paper, the significant wavelengths which can be used to separate the six mangrove species at Matang Mangrove Forest Reserve (MMFR), Perak were examined. The investigated mangrove species comprise of Rhizophora apiculata, Acrostichum aurem, Acrostichum speciosum, Acanthus ilicifolius, Ceriops tagal and Sonneratia ovata. In-situ spectral reflectance data of six mangrove species's leaf were obtained using ASD FieldSpec3 spectroradiometer and were statistically tested using SPSS program. First, wavelengths which exhibited significant differences (P value<0.05) among the mean reflectance of six mangrove species were identified using a series of one way ANOVA. Second, the identified wavelengths were further analyzed using canonical stepwise discriminant analysis and 26 significant wavelengths were obtained which can be utilized to distinguish among the six mangrove species. In conclusion, each mangrove species in MMFR have it own unique reflectance properties and these characteristic enable the mangrove species can be discriminated among each other under proper analysis and data extraction.

  8. 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.

  9. 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).

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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. PMID:24461713

  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. Nutrient composition of Kansas swine lagoons and hoop barn manure.

    PubMed

    DeRoucheys, J M; Goodband, R D; Nelssen, J L; Tokach, M D; Dritz, S S; Murphy, J P

    2002-08-01

    A total of 312 samples in two experiments were analyzed to determine mean nutrient concentrations of swine lagoons and hoop barns in Kansas. First, in a retrospective study (Exp. 1), we obtained 41 sample analyses from the Kansas Department of Agriculture of sow, nursery, wean-to-finish, finish, and farrow-to-finish operations in 1999. The average total N concentration was 899 ppm (SD = 584 ppm), while the total P concentration was 163 ppm (SD = 241 ppm). In an attempt to reduce the variation, we conducted a prospective experiment standardizing collection procedure, laboratory techniques, phase of production, and season of year to more accurately determine the nutrient concentrations of swine lagoons in Kansas. In Exp. 2, we used 236 lagoon and 35 hoop barn manure samples taken in 2000 from Kansas swine operations to determine the impacts of production phase and season of the year on nutrient concentration. The different operations with swine lagoons were: 1) sow; 2) nursery; 3) wean-to-finish; 4) finish; and 5) farrow-to-finish, with a total of 9, 8, 7, 10, and 8 lagoons sampled from each phase of production, respectively. The total N and P concentrations from lagoons were 1,402 and 204 ppm, respectively, averaged over all samples. Concentrations of total N were higher in wean-to-finish and finishing lagoons (P < 0.05) compared with sow and farrow-to-finish lagoons. Lagoon analyses also revealed that N concentrations decreased (linear, P < 0.05) during the summer and fall compared with winter and early spring. The concentration of P was greater (P < 0.05) for wean-to-finish compared with farrow-to-finish lagoons. Phosphorus concentrations for all lagoons increased (quadratic, P < 0.05) from February until June, but then declined steady throughout the remainder of the year. Average total N and P in hoop barns were 8,678 and 4,364 ppm, respectively. No seasonal changes in N and P concentrations were observed in manure from hoop barns. Season and type of production

  18. 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.

  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. 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

  1. 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

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

    PubMed

    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

    2012-04-01

    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 10(4) in A. schaeriana and 6.26 x 10(3) 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

  3. 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.

  4. 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

  5. [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.

  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. 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.

  8. Decomposition of mangrove roots: Effects of location, nutrients, species identity and mix in a Kenyan forest

    NASA Astrophysics Data System (ADS)

    Huxham, Mark; Langat, Joseph; Tamooh, Fredrick; Kennedy, Hilary; Mencuccini, Maurizio; Skov, Martin W.; Kairo, James

    2010-06-01

    Mangrove trees may allocate >50% of their biomass to roots. Dead roots often form peat, which can make mangroves significant carbon sinks and allow them to raise the soil surface and thus survive rising sea levels. Understanding mangrove root production and decomposition is hence of theoretical and applied importance. The current work explored the effects of species, site, and root size and root nutrients on decomposition. Decomposition of fine (≤3 mm diameter) and coarse (>3 mm diameter, up to a maximum of ˜9 mm) roots from three mangrove species, Avicennia marina, Bruguiera gymnorrhiza and Ceriops tagal was measured over 12 months at 6 sites along a tidal gradient in Gazi Bay, Kenya. C:N and P:N ratios in fresh and decomposed roots were measured, and the effects on decomposition of root size and age, of mixing roots from A. marina and C. tagal, of enriching B. gymnorrhiza roots with N and P and of artefacts caused by bagging roots were recorded. There were significant differences between species, with 76, 47 and 44 % mean dry weight lost after one year for A. marina, B. gymnorrhiza and C. tagal respectively, and between sites, with generally slower decomposition at dryer, high tidal areas. N enriched B. gymnorrhiza roots decomposed significantly faster than un-enriched controls; there was no effect of P enrichment. Mixing A. marina and C. tagal roots caused significantly enhanced decomposition in C. tagal. These results suggest that N availability was an important determinant of decomposition, since differences between species reflected the initial C: N ratios. The relatively slow decomposition rates recorded concur with other studies, and may overestimate natural rates, since larger (10-20 mm diameter), more mature and un-bagged roots all showed significantly slower rates.

  9. 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

  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. 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

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

    PubMed Central

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

    2013-01-01

    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

  13. 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

  14. 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.

  15. Temperature variability in a shallow, tidally isolated coral reef lagoon

    NASA Astrophysics Data System (ADS)

    McCabe, R. M.; Estrade, P.; Middleton, J. H.; Melville, W. K.; Roughan, M.; Lenain, L.

    2010-12-01

    Temperature data collected in the shallow, tidally isolated reef flat/lagoon of Lady Elliot Island off Queensland, Australia, show marked variability under solar and tidal forcing. Sea level drops below the height of the protective lagoon rim for a few hours during low tide, effectively isolating the remaining water. Because the lagoon is shallow, its temperature change (from diurnal solar forcing and cooling) is amplified. We develop a simple analytical model to predict the time evolution of mean lagoon temperature, beginning with a well-mixed control volume. This approach highlights the asymmetric flood/ebb physics of tidally isolated lagoons. After discussing the response of this model, we compare it with results from two idealized numerical simulations that illustrate differing aspects of lagoon temperature variability under "potential flow" and "prevailing current" situations. The conceptual model captures the essence of lagoon temperature variability and underscores the importance of solar-lunar phasing. However, because of the well-mixed assumption, it cannot reproduce sudden temperature transitions associated with new incoming water masses. Observations show that a slowly progressing thermal wave inundates the lagoon on rising tides. This wave is similar to our "potential flow" simulation in that it is approximately radially symmetric. On the other hand, it appears to advectively replace resident lagoon water, similar to our "prevailing current" simulations. We attempt to account for this behavior with a simple "frontal" modification to our conceptual model. Results show that this frontal model is able to capture the sudden temperature transitions present in the data and offers improved predictive capabilities over the well-mixed model.

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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).

  3. 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.

  4. Is the Venice Lagoon Noisy? First Passive Listening Monitoring of the Venice Lagoon: Possible Effects on the Typical Fish Community.

    PubMed

    Bolgan, Marta; Picciulin, Marta; Codarin, Antonio; Fiorin, Riccardo; Zucchetta, Matteo; Malavasi, Stefano

    2016-01-01

    Three passive listening surveys have been carried out in two of the three Venice lagoon tide inlets and inside the Venice island. The spectral content and the intensity level of the underwater noise as well as the presence or absence of Sciaena umbra and the distribution of its different sound patterns have been investigated in all the recording sites. The passive listening proved to be successful in detecting S. umbra drumming sounds in both Venice lagoon tide inlets. Our results indicate that the spectral content and the level of underwater noise pollution in the Venice lagoon could affect fish acoustic communication. PMID:26610947

  5. 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…

  6. 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

  7. 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.

  8. 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. PMID:26175962

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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.

  14. 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. PMID:24405426

  15. 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

  16. 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

  17. 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%.

  18. 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...

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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. PMID:27021267

  4. 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.

  5. 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.

  6. 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

  7. 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. PMID:24883249

  8. 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

  9. 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

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

    PubMed

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

    2016-08-30

    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. PMID:26971817

  11. 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.

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

    PubMed

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

    2016-08-30

    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.

  13. Toxicants from mangrove plants, VI. Heritonin, a new piscicide from th mangrove plant Heritiera littoralis.

    PubMed

    Miles, D H; Ly, A M; Chittawong, V; de la Cruz, A A; Gomez, E D

    1989-01-01

    The mangrove plant Heritiera littoralis has been utilized by natives of the Philippines as a fish poison. The petroleum ether extract of this plant has shown toxicity to fish (Tilapia nilotica). A new piscicide, which was assigned the name heritonin [1], has been identified as one of the compounds with ichthyotoxicity. The structure was elucidated by spectroscopic methods. PMID:2809613

  14. 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.

  15. 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

  16. Nutrient inputs to a Lagoon through submarine groundwater discharge: The case of Laoye Lagoon, Hainan, China

    NASA Astrophysics Data System (ADS)

    Ji, Tao; Du, Jinzhou; Moore, Willard S.; Zhang, Guosen; Su, Ni; Zhang, Jing

    2013-02-01

    Submarine groundwater discharge (SGD) with inputs of nutrients in certain regions may play a significant role in controlling water quality in the coastal regions. In this paper, we have determined four naturally occurring radium isotope (223Ra, 224Ra, 226Ra and 228Ra) activities and nutrient concentrations in surface water, coastal groundwater and river water in the mixing zone of Laoye Lagoon to estimate the fluxes of SGD by several models. The activities of the four radium isotopes of ground water were considerably greater than those in surface water samples. Using a 224Ra/228Ra activity ratio (AR) model, we estimated the average lagoon water age to be 3.2 days, which was comparable with the flushing time of 4.0 days. Based on the excess radium isotopes and the water age of the lagoon, the estimated fluxes of SGD (in 106 m3/d) ranged from 2.64 to 5.32 with an average of 4.11. Moreover, we used Si balance to evaluate the flux of SGD (4.8 × 106 m3/d) which was close to the result calculated by radium. The SGD-derived nutrient fluxes (in mol/d) were DIN = 1.7 × 105, PO43 - = 5.2 × 102, and SiO3 = 5.3 × 104. Furthermore, we applied the biogeochemical budget approach using SiO3 as a tracer to evaluate the impact of SGD. The differences between the results estimated by radium and SiO3 may indicate different pathways for the input of nutrients.

  17. 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.

  18. 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.

  19. 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.

  20. [Structure and dynamics of the mangrove forest in the Rancheria River delta, Colombian Caribbean].

    PubMed

    Lema Vélez, Luisa Fernanda; Polanía, Jaime

    2007-03-01

    We registered seedling survival and biomass increase for Rhizophora mangle L., Avicennia germinans L. and Laguncularia racemosa (L.) Gaertn. f, main mangrove species in the Rancheria River delta, Colombia. Only seedlings of R. mangle were found to survive. We also measured maximum rate of litterfall. We estimated annual litterfall through interpolation within an exponential regression performed with maximum and annual litterfall data published in other sources; the value of annual litterfall for the area was estimated to be 12.9 mgha(-1)y(-1). We found a 7.4 mgha(-1)y(-1)(-1) increase in biomass. Litterfall constitutes the larger fraction of the 20.2 mgha(-1)y(-1) productivity of this mangrove. We believe this is a very high value for a forest under unfavorable natural and human conditions, such as high seasonality and continuous use of the forest to feed goats and sheep. We consider that the high productivity is a response to both natural and anthropogenic stress. PMID:18457110

  1. 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

  2. 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.

  3. 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

  4. 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. PMID:27250698

  5. 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.

  6. 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.

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

    PubMed

    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

  8. Mapping the Philippines’ Mangrove Forests Using Landsat Imagery

    PubMed Central

    Long, Jordan B.; 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. PMID:22163779

  9. Mapping the Philippines' mangrove forests using Landsat imagery.

    PubMed

    Long, Jordan B; 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. PMID:22163779

  10. 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.

  11. 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

  12. Mapping the Philippines' mangrove forests using Landsat imagery

    USGS Publications Warehouse

    Long, J.B.; Giri, C.

    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. ?? 2011 by the authors; licensee MDPI, Basel, Switzerland.

  13. 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.

  14. 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.

  15. 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.

  16. 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. PMID:27265732

  17. 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.

  18. 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...

  19. Spatiotemporal distribution of the magnetotactic multicellular prokaryote Candidatus Magnetoglobus multicellularis in a Brazilian hypersaline lagoon and in microcosms.

    PubMed

    Martins, Juliana L; Silveira, Thais S; Abreu, Fernanda; de Almeida, Fernando P; Rosado, Alexandre S; Lins, Ulysses

    2012-09-01

    Candidatus Magnetoglobus multicellularis is an unusual morphotype of magnetotactic prokaryotes. These microorganisms are composed of a spherical assemblage of gram-negative prokaryotic cells capable of swimming as a unit aligned along a magnetic field. While they occur in many aquatic habitats around the world, high numbers of Ca. M. multicellularis have been detected in Araruama Lagoon, a large hypersaline lagoon near the city of Rio de Janeiro, in Brazil. Here, we report on the spatiotemporal distribution of one such population in sediments of Araruama Lagoon, including its annual distribution and its abundance compared with the total bacterial community. In microcosm experiments, Ca. M. multicellularis was unable to survive for more than 45 days: the population density gradually decreased coinciding with a shift to the upper layers of the sediment. Nonetheless, Ca. M. multicellularis was detected throughout the year in all sites studied. Changes in the population density seemed to be related to the input of organic matter as well as to salinity. The population density of Ca. M. multicellularis did not correlate with the total bacterial counts; instead, changes in the microbial community structure altered their counts in the environment.

  20. 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.

  1. Dynamic modelling of nitrification in an aerated facultative lagoon.

    PubMed

    Houweling, Dwight; Kharoune, Lynda; Escalas, Antoni; Comeau, Yves

    2008-01-01

    Faced with the need to improve ammonia removal from lagoon wastewater treatment plants (WWTPs) operated in Quebec, Canada, mechanistic modelling has been proposed as a tool for explaining the seasonal nitrification phenomenon and to evaluate optimization and upgrade scenarios. A lagoon model that includes a modified activated sludge biokinetic model and that assumes completely mixed conditions in the water column and sediments has been applied to simulate 3 years of consecutive effluent data for a lagoon from the Drummondville WWTP. Successful prediction of results from this plant indicates that the seasonal nitrification is determined by temperature, dissolved oxygen (DO) concentrations, hydraulic retention time (HRT) of the water column and washout driven by a well-mixed water column. Results also indicate that sediments contribute to the ammonia load in the lagoon effluent, particularly in spring and early summer. Sensitivity analyses performed with the model indicate that the nitrification period could be prolonged by increasing DO concentrations in the lagoon and that bioaugmentation would be particularly effective in spring and early summer. Limitations of the model are discussed, as well as ways to improve the hydraulic model.

  2. 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.

  3. 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.

  4. 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.

  5. [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.

  6. [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. PMID:15266816

  7. 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 ...

  8. 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.

  9. Spring and Summer Proliferation of Floating Macroalgae in a Mediterranean Coastal Lagoon (Tancada Lagoon, Ebro Delta, NE Spain)

    NASA Astrophysics Data System (ADS)

    Menéndez, M.; Comín, F. A.

    2000-08-01

    During the last 10 years, a drastic change in the structure of the community of primary producers has been observed in Tancada Lagoon (Ebro Delta, NE Spain). This consisted of a decrease in the abundance of submerged rooted macrophyte cover and a spring and summer increase in floating macroalgae. Two spatial patterns have been observed. In the west part of the lagoon, Chaetomorpha linum Kützing, dominated during winter and decreased progressively in spring when Cladophora sp. reached its maximum development. In the east part of the lagoon, higher macroalgal diversity was observed, together with lower cover in winter and early spring. Cladophora sp., Gracilaria verrucosa Papenfuss and Chondria tenuissima Agardh, increased cover and biomass in summer. Maximum photosynthetic production was observed in spring for G. verrucosa (10·9 mg O 2 g -1 DW h -1) and C. tenuissima (19·0 mg O 2 g -1 DW h -1) in contrast with Cladophora sp. (15·9 mg O 2 g -1 DW h -1) and Chaetomorpha linum (7·2 mg O 2 g -1 DW h -1) which reached maximum production in summer. Increased conductivity from reduced freshwater inflow, and higher water temperatures during periods of lagoon isolation, mainly in summer, were the main physical factors associated with an increase in floating macroalgal biomass across the lagoon. Reduced nitrogen availability and temperature-related changes in carbon availability during summer were related to a decrease in abundance of C. linum and increases in G. verrucosa and Cladophora sp.

  10. The genetic structure of the rare lagoonal sea anemone, Nematostella vectensis Stephenson (Cnidaria; Anthozoa) in the United Kingdom based on RAPD analysis.

    PubMed

    Pearson, C V M; Rogers, A D; Sheader, M

    2002-11-01

    The sea anemone Nematostella vectensis occurs in lagoons in the United States and along the southern and eastern coasts of the United Kingdom. In the United Kingdom it is considered rare and is threatened, principally through the destruction of lagoonal habitat. Random amplified polymorphic DNA (RAPD) data from populations across most of the rane of N. vectensis in the United Kingdom revealed that 61% of individuals had an identical genotype, the frequency of which varied from 0.01 to 1.00. These data provide strong evidence for predominantly clonal reproduction and for the existence of a 'general-purpose genotype' in the UK populations. Alternatively, the low levels of genetic variation observed in some N. vectensis populations may have resulted if they were founded from very few successful individuals from the United States. Analysis of molecular variance (amova) showed significant genetic differentiation between lagoons with no large-scale pattern of geographical variation. This result is consistent with occasional passive or anthropogenic dispersal of low numbers of individuals between lagoons followed by asexual proliferation of immigrants. Transplantation of individuals of the predominant (general-purpose) genotype, for conservation purposes, will probably stand a good chance of survival given its prevalence throughout the United Kingdom.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Coastal erosion and mangrove progradation of Southern Thailand

    NASA Astrophysics Data System (ADS)

    Thampanya, U.; Vermaat, J. E.; Sinsakul, S.; Panapitukkul, N.

    2006-06-01

    Approximately 60% of the southern Thai coastline used to be occupied by mangroves according to the first mangrove forest assessment in 1961. During the past three decades, these mangrove areas have been reduced to about 50% with less than 10% left on the east coast. Coastal erosion and accretion occur irregularly along the coast but an intensification of erosion has been noticed during the past decade. This study assessed the relationship between mangrove presence and changes in coastal area. Mangrove colonization rates were assessed using in situ transects and remote sensing time series. Both methods led to comparable estimates ranging between 5 and 40 m y -1. Quantitative data on changes of coastal segments along southern Thai coastlines as well as available possible factors responsible for these changes were compiled. Overall, net erosion prevailed (1.3 ± 0.4 m y -1). The Gulf of Thailand coastline in the East of the country was found to be most dynamic: change occurred along more coastal segments than in the West (43% vs. 16%). Rates of erosion and accretion were also higher, 3.6 versus 2.9 m y -1 and 2.6 versus 1.5 m y -1, respectively. Total area losses accounted for 0.91 km 2 y -1 for the Gulf coast and 0.25 km 2 y -1 for the West. Coasts with and without mangroves behaved differently: in the presence of mangroves less erosion was observed whilst expansion occurred at particular coastal types with mangrove existence, i.e. river mouths and sheltered bays. Possible underlying causes were examined using multivariate analysis. Eroded areas were found to increase with increased area of shrimp farms, increased fetch to the prevailing monsoon, and when dams reduced riverine inputs. Notably, however, in areas where erosion prevailed, the presence of mangroves reduced these erosion rates. Mangrove loss was found to be higher in the presence of shrimp farms and in areas where mangrove forests used to be extensive in the past.

  2. 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

  3. 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.

  4. 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. PMID:27008421

  5. 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.

  6. Pristine mangrove creek waters are a sink of nitrous oxide.

    PubMed

    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 × 10(8) 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.

  7. 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

  8. Pristine mangrove creek waters are a sink of nitrous oxide.

    PubMed

    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 × 10(8) 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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  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 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

  15. 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. *

  16. 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. PMID:26407146

  17. HYDROBIOLOGICAL CHARACTERISTICS OF THE COASTAL LAGOONS AT HUGH TAYLOR BIRCH STATE RECREATION AREA, FORT LAUDERDALE, FLORIDA: A HISTORICAL PERSPECTIVE.

    USGS Publications Warehouse

    Brock, Robert J.

    1987-01-01

    The author presents initial results of an ongoing study of Southeast Florida coastal lagoon lakes. Objectives include presenting environmental conditions within and adjacent to the lagoons under a variety of hydrologic conditions and to determine water-quality changes in ground water and surface water and how these changes in water quality affect lagoonal biological communities within the lagoons.

  18. Lagoon Seepage Testing Procedures for Central Facilities Area (CFA) Sewage Lagoons at Idaho National Laboratory Butte County, Idaho April 2014

    SciTech Connect

    Alan Giesbrecht

    2014-05-01

    The lagoon seepage testing procedures are documented herein as required by the Wastewater Rules (IDAPA 58.01.16.493). The Wastewater Rules and Wastewater Reuse Permit LA-000141-03 require that the procedure used for performing a seepage test be approved by IDEQ prior to conducting the seepage test. The procedures described herein are based on a seepage testing plan that was developed by J-U-B ENGINEERS, Inc. (J-U-B) and has been accepted by several IDEQ offices for lagoons in Idaho.

  19. 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.

  20. 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.

  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. 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

  3. Shrimp pond effluent dominates foliar nitrogen in disturbed mangroves as mapped using hyperspectral imagery.

    PubMed

    Fauzi, Anas; Skidmore, Andrew K; van Gils, Hein; Schlerf, Martin; Heitkönig, Ignas M A

    2013-11-15

    Conversion of mangroves to shrimp ponds creates fragmentation and eutrophication. Detection of the spatial variation of foliar nitrogen is essential for understanding the effect of eutrophication on mangroves. We aim (i) to estimate nitrogen variability across mangrove landscapes of the Mahakam delta using airborne hyperspectral remote sensing (HyMap) and (ii) to investigate links between the variation of foliar nitrogen mapped and local environmental variables. In this study, multivariate prediction models achieved a higher level of accuracy than narrow-band vegetation indices, making multivariate modeling the best choice for mapping. The variation of foliar nitrogen concentration in mangroves was significantly influenced by the local environment: (1) position of mangroves (seaward/landward), (2) distance to the shrimp ponds, and (3) predominant mangrove species. The findings suggest that anthropogenic disturbances, in this case shrimp ponds, influence nitrogen variation in mangroves. Mangroves closer to the shrimp ponds had higher foliar nitrogen concentrations.

  4. A new sampler for stratified lagoon chemical and microbiological assessments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A water column sampler was needed to study stratification of nutrients and bacteria in a swine manure lagoon. Conventional samplers yielded shallow samples near the bank or required a boat. These limitations prompted development of a new sampler to collect at multiple depths with minimal disturbanc...

  5. Antibiotic resistant bacterial profiles of anaerobic swine lagoon effluent.

    PubMed

    Brooks, J P; McLaughlin, M R

    2009-01-01

    Although land application of swine (Sus scrofa) manure lagoon effluent is a common and effective method of disposal, the presence of antibiotic-resistant bacteria, both pathogenic and commensal can complicate already understood issues associated with its safe disposal. The aim of this study was to assess antibiotic resistance in swine lagoon bacteria from sow, nursery, and finisher farms in the southeastern United States. Effluents from 37 lagoons were assayed for the presence of Escherichia coli, Campylobacter, Listeria, and Salmonella. Antibiotic resistance profiles were determined by the Kirby-Bauer swab method for 12 antibiotics comprising eight classes. Statistical analyses indicated that farm type influenced the amount and type of resistance, with nurseries and sow farms ranking as most influential, perhaps due to use of more antibiotic treatments. Finisher farms tended to have the least amount of antibiotic class resistance, signaling an overall healthier market pig, and less therapeutic or prophylactic antibiotic use. Many bacterial isolates were resistant to penicillin, cephalosporin, and tetracycline class antibiotics, while nearly all were susceptible to quinolone antibiotics. It appeared that swine farm type had a significant association with the amount of resistance associated with bacterial genera sampled from the lagoons; nurseries contributed the largest amount of bacterial resistance.

  6. LAGOON WATER FROM CONFINED ANIMAL FEED OPERATIONS AND AMPHIBIAN DEVELOPMENT

    EPA Science Inventory


    Lagoon Water from Confined Animal Feed Operations and Amphibian Development. Dumont, J. N.* and Slagle, S., Oklahoma State University, Stillwater, OK, and Hutchins, S. R., U.S. Environmental Protection Agency (NRMRL/SPRD), Ada, OK. There is some evidence that confined anima...

  7. Holocene carbonate sedimentation in Aitutaki Lagoon, Cook Islands, South Pacific

    SciTech Connect

    Richmond, B.M.; Hein, J.R.

    1987-05-01

    Aitutaki, an almost-atoll in the Southern Cook Islands, is characterized by a shallow enclosed lagoon. Sediment distribution within the lagoon can be broadly placed into three sedimentary-bathymetric provinces. (1) A low-relief reef rim (< 2 m deep), including sand flats and washover fans, is comprised mostly of clean sand and gravel. (2) The majority of the lagoon floor, which lies between 3 and 6 m water depth, is dominated by sand and silt; coral-algal patch reefs are common with densities greater than 500 reefs/km/sup 2/. Sediment commonly is coarser grained near the patch reefs. (3) Enclosed and elongate-sinuous topographic lows (basins) up to 10 m deep are marked by coral-algal reef growth along their margins. These features are typically narrow, less than 100 m wide, and are U-shaped in cross section and infilled by carbonate and terrigenous muds. High-resolution continuous seismic profiling and limited drilling indicate that differences in thickness of Holocene sediment result from primary irregularities in the pre-Holocene basement surface. Aitutaki was formed by late Miocene volcanism, with a post-edifice building mid-Pleistocene (0.77 Ma) volcanic episode. Two islets within the lagoon are also of volcanic origin, and sinuous coral ridges which extend for several kilometers probably developed on Quaternary lava flows. The coral ridges and meandering enclosed basins appear to be unique to Aitutaki in the Cook Islands.

  8. In Situ Monitoring of Malodors in a Swine Waste Lagoon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An apparatus for the in situ quantification of malodorous compounds from animal wastewater was developed that employed a submersible magnetic stir plate and stir bar sorbtive extraction using polydimethylsiloxane-coated stir bars. Prior to deployment of the apparatus in a hog waste lagoon, experime...

  9. Distribution and stability of eelgrass beds at Izembek Lagoon, Alaska

    USGS Publications Warehouse

    Ward, D.H.; Markon, C.J.; Douglas, D.C.

    1997-01-01

    Spatial change in eelgrass meadows, Zostera marina L., was assessed between 1978 and 1987 and between 1987 and 1995 at Izembek Lagoon, Alaska. Change in total extent was evaluated through a map to map comparison of data interpreted from a 1978 Landsat multi-spectral scanner image and 1987 black and white aerial photographs. A ground survey in 1995 was used to assess spatial change from 1987. Eelgrass beds were the predominant vegetation type in the lagoon, comprising 44-47% (15000-16000 ha) of the total area in 1978 and 1987. Izembek Lagoon contains the largest bed of seagrass along the Pacific Coast of North America and largest known single stand of eelgrass in the world. There was a high degree of overlap in the spatial distribution of eelgrass among years of change detection. The overall net change was a 6% gain between, 1978 and 1987 and a <1% gain between 1987 and 1995. The lack of significant change in eelgrass cover suggests that eelgrass meadows in Izembek Lagoon have been stable during the 17-year period of our study.

  10. Aerated Lagoons. Instructor's Guide. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Andersen, Lorri

    This unit (which consists of a single lesson) describes the structural and operationally unique features of aerated lagoons. In addition, special troubleshooting and maintenance problems are discussed. The instructor's guide for the unit includes: (1) an overview of the lesson; (2) lesson plan; (3) lecture outline (keyed to a set of slides used…

  11. Facultative Lagoons. Instructor's Guide. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Andersen, Lorri

    This instructor's guide contains materials needed to teach a two-lesson unit on the structure and components of facultative lagoons, the biological theory of their operation, and factors affecting their operation. Control testing recommendations, maintenance guidelines, and troubleshooting hints are also provided. These materials include: (1) an…

  12. A Field Study Training Program on Wastewater Lagoon Systems.

    ERIC Educational Resources Information Center

    Water and Wastewater Technical School, Neosho, MO.

    This publication is a text and reference manual for operating personnel of both large and small wastewater lagoon systems with support from the Environmental Protection Agency (EPA). As a text, this inservice training manual is intended to be used in a correspondence course wherein the trainee or operator would read and study each chapter before…

  13. Flushing of Bowden Reef lagoon, Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Wolanski, Eric; King, Brian

    1990-12-01

    Field and numerical studies were undertaken in 1986 and 1987 of the water circulation around and over Bowden Reef, a 5-km long kidney-shaped coral reef lagoon system in the Great Barrier Reef. In windy conditions, the flushing of the lagoon was primarily due to the intrusion into the lagoon of topographically induced tidal eddies generated offshore. In calm weather, such eddies did not prevail and lagoon flushing was much slower. The observed currents at sites a few kilometres apart in inter-reefal waters, have a significant horizontal shear apparently due to the complex circulation in the reef matrix. Under such conditions, sensitivity tests demonstrate the importance of including this shear in the specification of open boundary conditions of numerical models of the hydrodynamics around reefs. Contrary to established practice, the water circulation around a coral reef should not be modelled by assuming reefs are hydrodynamically isolated from surrounding ones. Little improvement appears likely in the reliability of reef-scale numerical models until the inter-reefal shear can be reliably incorporated in such models.

  14. Dolabranes from the Chinese Mangrove, Ceriops tagal.

    PubMed

    Hu, Wei-Min; Li, Min-Yi; Li, Jun; Xiao, Qiang; Feng, Gang; Wu, Jun

    2010-10-22

    Six new dolabranes, named tagalsins P-U (1-6), were isolated from stems and twigs of a Chinese mangrove, Ceriops tagal, along with seven known dolabranes, an abietane, and a pimarane. The structures of these compounds were established on the basis of spectroscopic data or comparison with data in the literature. The relative configurations of tagalsins P and Q (1, 2), two new 15,16-dinor-dolabranes, were confirmed by means of single-crystal X-ray diffraction analysis. This is the first report of 16-nordolabranes and 15,16-dinordolabranes from plants of the Ceriops genus. Tagalsins Q (2), R (3), and U (6) showed moderate antifeedant activity against the third-instar larvae of Brontispa longissima at a concentration of 1 mg/mL. However, none of the new dolabranes exhibited significant activity against human cancer cell lines.

  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. Aspects of fish conservation in the upper Patos Lagoon basin.

    PubMed

    Fontoura, N F; Vieira, J P; Becker, F G; Rodrigues, L R; Malabarba, L R; Schulz, U H; Möller, O O; Garcia, A M; Vilella, F S

    2016-07-01

    The Patos Lagoon basin is a large (201 626 km(2) ) and complex drainage system in southern Brazil. The lagoon is 250 km long and 60 km wide, covering an area of 10 360 km(2) . The exchange of water with the Atlantic Ocean occurs through a 0·8 km wide and 15 m deep inlet, fixed by 4 km long jetties, at the southernmost part of the Patos Lagoon. The estuarine area is restricted to its southern portion (10%), although the upper limit of saline waters migrates seasonally and year to year, influenced by the wind regime and river discharge. The known number of recorded limnetic fish species is 200, but this number is expected to increase. A higher endemism is observed in fish species occurring in upper tributaries. The basin suffers from the direct impact of almost 7 million inhabitants, concentrated in small to large cities, most with untreated domestic effluents. There are at least 16 non-native species recorded in natural habitats of the Patos Lagoon basin, about half of these being from other South American river basins. Concerning the fishery, although sport and commercial fisheries are widespread throughout the Patos Lagoon basin, the lagoon itself and the estuarine area are the main fishing areas. Landing statistics are not available on a regular basis or for the whole basin. The fishery in the northern Patos Lagoon captures 31 different species, nine of which are responsible for most of the commercial catches, but only three species are actually sustaining the artisanal fishery: the viola Loricariichthys anus: 455 kg per 10 000 m(2) gillnet per day, the mullet Mugil liza: 123 kg per 10 000 m(2) gillnet per day and the marine catfish Genidens barbus: 50 kg per 10 000 m(2) gillnet per day. A decline of the fish stocks can be attributed to inadequate fishery surveillance, which leads to overfishing and mortality of juveniles, or to decreasing water quality because of urban and industrial activities and power production. Global climatic changes also represent a

  18. Aspects of fish conservation in the upper Patos Lagoon basin.

    PubMed

    Fontoura, N F; Vieira, J P; Becker, F G; Rodrigues, L R; Malabarba, L R; Schulz, U H; Möller, O O; Garcia, A M; Vilella, F S

    2016-07-01

    The Patos Lagoon basin is a large (201 626 km(2) ) and complex drainage system in southern Brazil. The lagoon is 250 km long and 60 km wide, covering an area of 10 360 km(2) . The exchange of water with the Atlantic Ocean occurs through a 0·8 km wide and 15 m deep inlet, fixed by 4 km long jetties, at the southernmost part of the Patos Lagoon. The estuarine area is restricted to its southern portion (10%), although the upper limit of saline waters migrates seasonally and year to year, influenced by the wind regime and river discharge. The known number of recorded limnetic fish species is 200, but this number is expected to increase. A higher endemism is observed in fish species occurring in upper tributaries. The basin suffers from the direct impact of almost 7 million inhabitants, concentrated in small to large cities, most with untreated domestic effluents. There are at least 16 non-native species recorded in natural habitats of the Patos Lagoon basin, about half of these being from other South American river basins. Concerning the fishery, although sport and commercial fisheries are widespread throughout the Patos Lagoon basin, the lagoon itself and the estuarine area are the main fishing areas. Landing statistics are not available on a regular basis or for the whole basin. The fishery in the northern Patos Lagoon captures 31 different species, nine of which are responsible for most of the commercial catches, but only three species are actually sustaining the artisanal fishery: the viola Loricariichthys anus: 455 kg per 10 000 m(2) gillnet per day, the mullet Mugil liza: 123 kg per 10 000 m(2) gillnet per day and the marine catfish Genidens barbus: 50 kg per 10 000 m(2) gillnet per day. A decline of the fish stocks can be attributed to inadequate fishery surveillance, which leads to overfishing and mortality of juveniles, or to decreasing water quality because of urban and industrial activities and power production. Global climatic changes also represent a

  19. Sand mining and morphometric dynamics along Ologe Lagoon

    NASA Astrophysics Data System (ADS)

    Thaddeus, D.; Odunuga, S.

    2015-04-01

    The study focuses on the sand mining activities and morphometric dynamics of Ologe Lagoon, in Lagos, Nigeria. It determines the sand mining activities and morphometric dynamics of Ologe Lagoon catchment area, the quantity of sand mined per unit time, and the extent of environmental degradation due to the continuous sand mining activities. Topographic maps of the 1985 and 2013 Ikonos satellite imagery were used to identify the morphometric dynamics of the area. Two hypotheses were generated to determine if there are significant differences between the means of the sampled population that lost properties due to flooding, and to determine if there was a correlation between building subsidence and loss of property; it was tested using Analysis of Variance (ANOVA) with a correlation coefficient at 0.05 α significance level. The results of geometric measurement of the Ologe Lagoon between the two years interval show that perimeter width and circularity of the basin had reduced and shrunk, while the form factor remains the same at 0.15 km2. The basin elongation increased significantly by 0.01 km2, thus, increasing the rate at which water will be supplied to the lagoon. The ration of the form factor of 0.69/0.5 is close to the unity value R1, which shows a higher peak runoff; the values of the circularity ratio of 3.94/3.13 indicates circularity. This shows that the basin is circular time. The impact of the geometry indicates the development of mud flats and sandy bars, particularly at the lower portion of the lagoon; there is also modification of sediment deposition. The anthropogenic activity of sand mining causes destruction of the riparian forest around the lagoon. There is no significant difference in the means of sampled respondents regarding loss properties due to flooding, while there is a correlation between building subsidence and loss of life. It is recommended that a road map should be developed and implemented by the relevant agency of the government to guide

  20. Remediation of heavy metal contaminated sites in the Venice lagoon and conterminous areas (Northern Italy)

    NASA Astrophysics Data System (ADS)

    Bini, Claudio; Wahsha, Mohammad; Fontana, Silvia; Maleci, Laura

    2013-04-01

    IPA was recorded, while groundwater proved to be contaminated by As, Cd, Cr, Hg, Pb, Cu, Se, Ni, Mn, Sb, Fe. Restoration of the studied sites has been carried out by phytoremediation with native or exotic vegetation (Fragmites australis, Juncus lacustris,Puccinellia palustris, Limonium serotinum, Salicornia glauca, Spartina maritima, Pteris vittata) or cultivated plants (Heliantus annuus, Zea mais, Brassica napus, Brassica juncea). Results are somewhat contradictory. At S. Giuliano, the exotic fern (Pteris vittata), consistently with data from current literature, showed high ability to accumulate As, particularly in aerial parts. At Campalto, native vegetation proved ineffective for phytoextraction, but suitable for phytostabilization, owing to a root barrier effect. In the lagoon sediments from Marghera, Spartina proved more effective than Fragmites to uptake metals, while cultivated plants could not survive to high heavy metal concentrations. At Murano, Pteris vittata proved highly effective to accumulate As, but also resistant to elevated concentrations of co-existing metals (Cd, Pb, Se, Zn), with clear signals of growth sufference and a drastic reduction of sorption capacity only in the presence of very high Cd concentration. At Molo Serbatoi, phytoremediation could not be applied in absence of a chelating agent (e.g. EDTA), which could enhance metal mobilization: therefore, soil has been stored, selected and finally (the most contaminated part) delivered to a landfill, while groundwater will be remediated by bioremediation techniques.

  1. 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

  2. Vulnerability to climate change of mangroves: assessment from cameroon, central Africa.

    PubMed

    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

  3. 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

  4. Nitrification and denitrification gene abundances in swine wastewater anaerobic lagoons.

    PubMed

    Ducey, Thomas F; Shriner, Anthony D; Hunt, Patrick G

    2011-01-01

    Although anaerobic lagoons are used globally for livestock waste treatment, their detailed microbial cycling ofN is only beginning to become understood. Within this cycling, nitrification can be performed by organisms that produce the enzyme ammonia monooxygenase. For denitrification, the reduction of nitrite to nitric oxide can be catalyzed by two forms of nitrite reductases, and N,O can be reduced by nitrous oxide reductase encoded by the gene nosZ The objectives of this investigation were to (i) quantify the abundance of the amoA, nirK, nirS, and nosZ genes; (ii) evaluate the influence of environmental conditions on their abundances; and (iii) evaluate their abundance relative to denitrification enzyme activity (DEA). Samples were analyzed via real-time quantitative polymerase chain reaction and collected from eight typical, commercial anaerobic, swine wastewater lagoons located in the Carolinas. The four genes assayed in this study were present in all eight lagoons. Their abundances relative to total bacterial populations were 0.04% (amoA), 1.33% (nirS), 5.29% (nirK), and 0.27% (nosZ). When compared with lagoon chemical characteristics, amoA and nirK correlated with several measured variables. Neither nirS nor nosZ correlated with any measured environmental variables. Although no gene measured in this study correlated with actual or potential DEA, nosZ copy numbers did correlate with the disparity between actual and potential DEA. Phylogenetic analysis ofnosZdid not reveal any correlations to DEA rates. As with other investigations, analyses of these genes provide useful insight while revealing the underlying greater complexity of N cycling within swine waste lagoons. PMID:21520768

  5. Nitrification and denitrification gene abundances in swine wastewater anaerobic lagoons.

    PubMed

    Ducey, Thomas F; Shriner, Anthony D; Hunt, Patrick G

    2011-01-01

    Although anaerobic lagoons are used globally for livestock waste treatment, their detailed microbial cycling ofN is only beginning to become understood. Within this cycling, nitrification can be performed by organisms that produce the enzyme ammonia monooxygenase. For denitrification, the reduction of nitrite to nitric oxide can be catalyzed by two forms of nitrite reductases, and N,O can be reduced by nitrous oxide reductase encoded by the gene nosZ The objectives of this investigation were to (i) quantify the abundance of the amoA, nirK, nirS, and nosZ genes; (ii) evaluate the influence of environmental conditions on their abundances; and (iii) evaluate their abundance relative to denitrification enzyme activity (DEA). Samples were analyzed via real-time quantitative polymerase chain reaction and collected from eight typical, commercial anaerobic, swine wastewater lagoons located in the Carolinas. The four genes assayed in this study were present in all eight lagoons. Their abundances relative to total bacterial populations were 0.04% (amoA), 1.33% (nirS), 5.29% (nirK), and 0.27% (nosZ). When compared with lagoon chemical characteristics, amoA and nirK correlated with several measured variables. Neither nirS nor nosZ correlated with any measured environmental variables. Although no gene measured in this study correlated with actual or potential DEA, nosZ copy numbers did correlate with the disparity between actual and potential DEA. Phylogenetic analysis ofnosZdid not reveal any correlations to DEA rates. As with other investigations, analyses of these genes provide useful insight while revealing the underlying greater complexity of N cycling within swine waste lagoons.

  6. Water sources, mixing and evaporation in the Akyatan lagoon, Turkey

    NASA Astrophysics Data System (ADS)

    Lécuyer, C.; Bodergat, A.-M.; Martineau, F.; Fourel, F.; Gürbüz, K.; Nazik, A.

    2012-12-01

    Akyatan lagoon, located southeast of Turkey along the Mediterranean coast, is a choked and hypersaline lagoon, and hosts a large and specific biodiversity including endangered sea turtles and migrating birds. Physicochemical properties of this lagoon were investigated by measuring temperature, salinity, and hydrogen and oxygen isotope ratios of its waters at a seasonal scale during years 2006 and 2007. Winter and spring seasons were dominated by mixing processes between freshwaters and Mediterranean seawater. The majority of spring season waters are formed by evapoconcentration of brackish water at moderate temperatures of 22 ± 2 °C. During summer, hypersaline waters result from evaporation of seawater and brackish waters formed during spring. Evaporation over the Akyatan lagoon reaches up to 76 wt% based on salinity measurements and operated with a dry (relative humidity of 0.15-0.20) and hot (44 ± 6 °C) air. These residual waters were characterized by the maximal seasonal isotopic enrichment in both deuterium and 18O relative to VSMOW. During autumn, most lagoonal waters became hypersaline and were formed by evaporation of waters that had isotopic compositions and salinities close to that of seawater. These autumnal hypersaline waters result from an air humidity close to 0.45 and an atmospheric temperature of evaporation of 35 ± 5 °C, which are responsible for up to 71 wt% of evaporation, with restricted isotopic enrichments relative to VSMOW. During the warm seasons, the combination of air humidity, wind velocity and temperature were responsible for a large kinetic component in the total isotopic fractionation between water liquid and water vapour.

  7. Atmospheric input of organic pollutants to the Venice Lagoon.

    PubMed

    Rossini, P; De Lazzari, A; Guerzoni, S; Molinaroli, E; Rampazzo, G; Zancanaro, A

    2001-01-01

    The atmospheric deposition of dioxins and furans (PCDD-Fs), dioxin-like polychlorobyphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and hexachlorobenzene (HCB) was determined in the Lagoon of Venice. Sampling was carried out monthly, for a total of 13 months (July 1998-July 1999) using "bulk" samplers (passive collectors of wet and dry depositions) at four sites, inside the lagoon and close to its edge. Calculated PCDD-F loadings to the Lagoon turned out to be quite homogeneous, their range being approximately 10-20 ng m-2 y-1, whereas in the station located close to the industrial zone of Porto Marghera the value was approximately 50 ng m-2 y-1. PCB deposition in the industrial fallout sampling site and in the city centre of Venice was approximately 2500 ng m-2 y-1, that is, almost five times higher than the values measured at the northern and southern lagoon stations. HCB annual loading (approximately 8000 ng m-2 y-1) was almost six times higher in the industrial zone than in the other sites (approximately 1500 ng m-2 y-1). PAH loadings in the city centre of Venice and at Porto Marghera were 314 and 389 micrograms m-2 y-1, respectively. The amount of 2,3,7,8-TCDD equivalents (TEQ) of PCDD-Fs and PCBs in the Venice and Porto Marghera bulk depositions was compared with the guideline value of 15 pg m-2 d-1 for dioxins in depositions proposed by De Fré et al. (1998). Moreover, as some of the effects which drive the risk assessment of dioxin-like compounds were also observed after exposure to other molecules, the TEQs of PAHs and HCB were also calculated: nine out of 13 samples exceeded the guideline value. Lastly, an atmospheric emission source related to vinyl chloride monomer production, which may affect atmospheric deposition on the whole Lagoon, is reported in the industrial zone of Porto Marghera.

  8. 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.

  9. 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.

  10. Where temperate meets tropical: Multi-factorial effects of elevated CO2, nitrogen enrichment, and competition on a mangrove-salt marsh community

    USGS Publications Warehouse

    McKee, K.L.; Rooth, J.E.

    2008-01-01

    Our understanding of how elevated CO2 and interactions with other factors will affect coastal plant communities is limited. Such information is particularly needed for transitional communities where major vegetation types converge. Tropical mangroves (Avicennia germinans) intergrade with temperate salt marshes (Spartina alterniflora) in the northern Gulf of Mexico, and this transitional community represents an important experimental system to test hypotheses about global change impacts on critical ecosystems. We examined the responses of A. germinans (C3) and S. alterniflora (C4), grown in monoculture and mixture in mesocosms for 18 months, to interactive effects of atmospheric CO2 and pore water nitrogen (N) concentrations typical of these marshes. A. germinans, grown without competition from S. alterniflora, increased final biomass (35%) under elevated CO2 treatment and higher N availability. Growth of A. germinans was severely curtailed, however, when grown in mixture with S. alterniflora, and enrichment with CO2 and N could not reverse this growth suppression. A field experiment using mangrove seedlings produced by CO2- and N-enriched trees confirmed that competition from S. alterniflora suppressed growth under natural conditions and further showed that herbivory greatly reduced survival of all seedlings. Thus, mangroves will not supplant marsh vegetation due to elevated CO2 alone, but instead will require changes in climate, environmental stress, or disturbance to alter the competitive balance between these species. However, where competition and herbivory are low, elevated CO2 may accelerate mangrove transition from the seedling to sapling stage and also increase above- and belowground production of existing mangrove stands, particularly in combination with higher soil N. ?? 2008 The Authors Journal compilation ?? 2008 Blackwell Publishing Ltd.

  11. Biogeochemical responses of shallow coastal lagoons to Climate Change

    NASA Astrophysics Data System (ADS)

    Brito, A.; Newton, A.; Tett, P.; Fernandes, T.

    2009-04-01

    The importance of climate change and global warming in the near future is becoming consensual within the scientific community (e.g. Kerr et al., 2008; Lloret et al., 2008). The surface temperature and sea level have increased during the last few years in the northern hemisphere (IPCC, 2007). Predictions for future changes include an increase of surface temperature and sea level for Europe. Moreover, the global warming phenomenon will also change the hydrological cycle and increase precipitation in northern and central Europe (IPCC, 2007). Sea level rise already threatens to overwhelm some lagoons, such as Venice and Moroccan lagoons (Snoussi et al., 2008). Shallow coastal lagoons are some of the most vulnerable systems that will be impacted by these changes (Eisenreich, 2005). Environmental impacts on coastal lagoons include an increase of water turbidity and therefore light attenuation. If these effects are strong enough, the lighted bottoms of shallow lagoons may loose a significant part of the benthic algal community. These communities are highly productive and are essential to control nutrient dynamics of the system by uptaking large amounts of nutrients both from the water column and from the sediments. A decrease in benthic algal communities and photosynthetic oxygen production will also contribute to increasing the vulnerability of the lagoons to hypoxia and anoxia. The flux of nutrients such as phosphate from the sediments may increase dramatically, further disrupting the nutrient balance and condition and promoting cyanobacterial blooms. Microbial activity is temperature dependent, therefore, the increase of temperature will increase the concentrations of ammonium within sediments. The release of phosphate and silicate will also increase with temperature. Coastal lagoons are valuable ecosystems and may be severely impacted, both ecologically and economically, by global change. Shallow coastal lagoons should be considered as sentinel systems and should be

  12. Crustacean zooplankton in aerated wastewater treatment lagoons as a potential feedstock for biofuel.

    PubMed

    Kring, Stefanie A; Xia, Xiaoyan; Powers, Susan E; Twiss, Michael R

    2013-01-01

    Zooplankton biomass productivity was estimated for two 64,000 m3 (1.7 ha) facultative aerated wastewater treatment lagoons to evaluate potential biodiesel production from zooplankton biomass. Lagoons were monitored bi-weekly during summer 2010. Lipid accumulated by crustacean zooplankton was considered the most efficient means by which to collect lipid produced by phytoplankton owing to the greater ease in the collection of these organisms (>0.153mm) compared with unicellular algae (size <0.06 mm). In terms of biomass, the cladoceran Daphnia and the copepod Cyclops were the dominant zooplankton in these hypereutrophic lagoons, while unicellular chlorophytes dominated the phytoplankton community. Secondary productivity of these lagoons (250 g of dry weight m(-2) yr(-1)) is comparable to the secondary productivity of other sewage lagoons. The potential biodiesel production for one lagoon was estimated to be 0.04 +/- 0.02 L m(-2) yr(-1), which results in a total of 1120 +/- 560 L from two lagoons. This study showed that there are organisms present in wastewater lagoons, besides algae, that can serve as a biofuel feedstock. Additionally, this research expands the current knowledge of facultative aerated wastewater lagoon ecology and waste stream-derived biofuel. Future research should include complete life cycle and economic analyses to determine if harvesting zooplankton from wastewater lagoons is a sustainable endeavour. PMID:24350451

  13. An integrated Pan-European perspective on coastal Lagoons management through a mosaic-DPSIR approach.

    PubMed

    Dolbeth, Marina; Stålnacke, Per; Alves, Fátima L; Sousa, Lisa P; Gooch, Geoffrey D; Khokhlov, Valeriy; Tuchkovenko, Yurii; Lloret, Javier; Bielecka, Małgorzata; Różyński, Grzegorz; Soares, João A; Baggett, Susan; Margonski, Piotr; Chubarenko, Boris V; Lillebø, Ana I

    2016-01-01

    A decision support framework for the management of lagoon ecosystems was tested using four European Lagoons: Ria de Aveiro (Portugal), Mar Menor (Spain), Tyligulskyi Liman (Ukraine) and Vistula Lagoon (Poland/Russia). Our aim was to formulate integrated management recommendations for European lagoons. To achieve this we followed a DPSIR (Drivers-Pressures-State Change-Impacts-Responses) approach, with focus on integrating aspects of human wellbeing, welfare and ecosystem sustainability. The most important drivers in each lagoon were identified, based on information gathered from the lagoons' stakeholders, complemented by scientific knowledge on each lagoon as seen from a land-sea perspective. The DPSIR cycles for each driver were combined into a mosaic-DPSIR conceptual model to examine the interdependency between the multiple and interacting uses of the lagoon. This framework emphasizes the common links, but also the specificities of responses to drivers and the ecosystem services provided. The information collected was used to formulate recommendations for the sustainable management of lagoons within a Pan-European context. Several common management recommendations were proposed, but specificities were also identified. The study synthesizes the present conditions for the management of lagoons, thus analysing and examining the activities that might be developed in different scenarios, scenarios which facilitate ecosystem protection without compromising future generations. PMID:26776151

  14. Crustacean zooplankton in aerated wastewater treatment lagoons as a potential feedstock for biofuel.

    PubMed

    Kring, Stefanie A; Xia, Xiaoyan; Powers, Susan E; Twiss, Michael R

    2013-01-01

    Zooplankton biomass productivity was estimated for two 64,000 m3 (1.7 ha) facultative aerated wastewater treatment lagoons to evaluate potential biodiesel production from zooplankton biomass. Lagoons were monitored bi-weekly during summer 2010. Lipid accumulated by crustacean zooplankton was considered the most efficient means by which to collect lipid produced by phytoplankton owing to the greater ease in the collection of these organisms (>0.153mm) compared with unicellular algae (size <0.06 mm). In terms of biomass, the cladoceran Daphnia and the copepod Cyclops were the dominant zooplankton in these hypereutrophic lagoons, while unicellular chlorophytes dominated the phytoplankton community. Secondary productivity of these lagoons (250 g of dry weight m(-2) yr(-1)) is comparable to the secondary productivity of other sewage lagoons. The potential biodiesel production for one lagoon was estimated to be 0.04 +/- 0.02 L m(-2) yr(-1), which results in a total of 1120 +/- 560 L from two lagoons. This study showed that there are organisms present in wastewater lagoons, besides algae, that can serve as a biofuel feedstock. Additionally, this research expands the current knowledge of facultative aerated wastewater lagoon ecology and waste stream-derived biofuel. Future research should include complete life cycle and economic analyses to determine if harvesting zooplankton from wastewater lagoons is a sustainable endeavour.

  15. An integrated Pan-European perspective on coastal Lagoons management through a mosaic-DPSIR approach.

    PubMed

    Dolbeth, Marina; Stålnacke, Per; Alves, Fátima L; Sousa, Lisa P; Gooch, Geoffrey D; Khokhlov, Valeriy; Tuchkovenko, Yurii; Lloret, Javier; Bielecka, Małgorzata; Różyński, Grzegorz; Soares, João A; Baggett, Susan; Margonski, Piotr; Chubarenko, Boris V; Lillebø, Ana I

    2016-01-18

    A decision support framework for the management of lagoon ecosystems was tested using four European Lagoons: Ria de Aveiro (Portugal), Mar Menor (Spain), Tyligulskyi Liman (Ukraine) and Vistula Lagoon (Poland/Russia). Our aim was to formulate integrated management recommendations for European lagoons. To achieve this we followed a DPSIR (Drivers-Pressures-State Change-Impacts-Responses) approach, with focus on integrating aspects of human wellbeing, welfare and ecosystem sustainability. The most important drivers in each lagoon were identified, based on information gathered from the lagoons' stakeholders, complemented by scientific knowledge on each lagoon as seen from a land-sea perspective. The DPSIR cycles for each driver were combined into a mosaic-DPSIR conceptual model to examine the interdependency between the multiple and interacting uses of the lagoon. This framework emphasizes the common links, but also the specificities of responses to drivers and the ecosystem services provided. The information collected was used to formulate recommendations for the sustainable management of lagoons within a Pan-European context. Several common management recommendations were proposed, but specificities were also identified. The study synthesizes the present conditions for the management of lagoons, thus analysing and examining the activities that might be developed in different scenarios, scenarios which facilitate ecosystem protection without compromising future generations.

  16. 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

  17. 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

  18. Mangrove pore water exchange across a latitudinal gradient

    NASA Astrophysics Data System (ADS)

    Tait, Douglas R.; Maher, Damien T.; Macklin, Paul A.; Santos, Isaac R.

    2016-04-01

    We combined observations of the natural tracer radon (222Rn) with hydrodynamic models across a broad latitudinal gradient covering several climate zones to estimate pore water exchange rates in mangroves. Pore water exchange ranged from 2.1 to 35.5 cm d-1 from temperate to tropical regions and averaged 16.3 ± 5.1 cm d-1. If upscaled to the global weighted mangrove area, pore water exchange in mangroves would recirculate the entire volume of water overlying the continental shelf in less than 153 years. Although pore water exchange (recirculated seawater) and river discharge represent different pathways for water entering the coastal ocean, the estimated global mangrove pore water exchange would be equal to approximately one third of annual global river discharge to the ocean (3.84 × 1013 m3 yr-1). Because biogeochemical processes in mangroves are largely dependent on pore water exchange, these large exchange rates have major implications for coastal nutrient, carbon, and greenhouse gas cycling in tropical marine systems.

  19. Small RNA transcriptomes of mangroves evolve adaptively in extreme environments

    PubMed Central

    Wen, Ming; Lin, Xingqin; Xie, Munan; Wang, Yushuai; Shen, Xu; Liufu, Zhongqi; Wu, Chung-I; Shi, Suhua; Tang, Tian

    2016-01-01

    MicroRNAs (miRNAs) and endogenous small interfering RNAs (siRNAs) are key players in plant stress responses. Here, we present the sRNA transcriptomes of mangroves Bruguiera gymnorrhiza and Kandelia candel. Comparative computational analyses and target predictions revealed that mangroves exhibit distinct sRNA regulatory networks that differ from those of glycophytes. A total of 32 known and three novel miRNA families were identified. Conserved and mangrove-specific miRNA targets were predicted; the latter were widely involved in stress responses. The known miRNAs showed differential expression between the mangroves and glycophytes, reminiscent of the adaptive stress-responsive changes in Arabidopsis. B. gymnorrhiza possessed highly abundant but less conserved TAS3 trans-acting siRNAs (tasiRNAs) in addition to tasiR-ARFs, with expanded potential targets. Our results indicate that the evolutionary alteration of sRNA expression levels and the rewiring of sRNA-regulatory networks are important mechanisms underlying stress adaptation. We also identified sRNAs that are involved in salt and/or drought tolerance and nutrient homeostasis as possible contributors to mangrove success in stressful environments. PMID:27278626

  20. Small RNA transcriptomes of mangroves evolve adaptively in extreme environments.

    PubMed

    Wen, Ming; Lin, Xingqin; Xie, Munan; Wang, Yushuai; Shen, Xu; Liufu, Zhongqi; Wu, Chung-I; Shi, Suhua; Tang, Tian

    2016-01-01

    MicroRNAs (miRNAs) and endogenous small interfering RNAs (siRNAs) are key players in plant stress responses. Here, we present the sRNA transcriptomes of mangroves Bruguiera gymnorrhiza and Kandelia candel. Comparative computational analyses and target predictions revealed that mangroves exhibit distinct sRNA regulatory networks that differ from those of glycophytes. A total of 32 known and three novel miRNA families were identified. Conserved and mangrove-specific miRNA targets were predicted; the latter were widely involved in stress responses. The known miRNAs showed differential expression between the mangroves and glycophytes, reminiscent of the adaptive stress-responsive changes in Arabidopsis. B. gymnorrhiza possessed highly abundant but less conserved TAS3 trans-acting siRNAs (tasiRNAs) in addition to tasiR-ARFs, with expanded potential targets. Our results indicate that the evolutionary alteration of sRNA expression levels and the rewiring of sRNA-regulatory networks are important mechanisms underlying stress adaptation. We also identified sRNAs that are involved in salt and/or drought tolerance and nutrient homeostasis as possible contributors to mangrove success in stressful environments. PMID:27278626

  1. Distribution and dynamics of mangrove forests of South Asia

    USGS Publications Warehouse

    Giri, Chandra; Long, Jordan; Abbas, Sawaid; Murali, R. Mani; Qamer, Faisal M.; Pengra, Bruce; Thau, David

    2014-01-01

    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 environmental conditions highlights complex patterns of mangrove distribution and change. Results from this study provide important insight to the conservation and management of the important and threatened South Asian mangrove ecosystem.

  2. Automatic Extraction of Mangrove Vegetation from Optical Satellite Data

    NASA Astrophysics Data System (ADS)

    Agrawal, Mayank; Sushma Reddy, Devireddy; Prasad, Ram Chandra

    2016-06-01

    Mangrove, the intertidal halophytic vegetation, are one of the most significant and diverse ecosystem in the world. They protect the coast from sea erosion and other natural disasters like tsunami and cyclone. In view of their increased destruction and degradation in the current scenario, mapping of this vegetation is at priority. Globally researchers mapped mangrove vegetation using visual interpretation method or digital classification approaches or a combination of both (hybrid) approaches using varied spatial and spectral data sets. In the recent past techniques have been developed to extract these coastal vegetation automatically using varied algorithms. In the current study we tried to delineate mangrove vegetation using LISS III and Landsat 8 data sets for selected locations of Andaman and Nicobar islands. Towards this we made an attempt to use segmentation method, that characterize the mangrove vegetation based on their tone and the texture and the pixel based classification method, where the mangroves are identified based on their pixel values. The results obtained from the both approaches are validated using maps available for the region selected and obtained better accuracy with respect to their delineation. The main focus of this paper is simplicity of the methods and the availability of the data on which these methods are applied as these data (Landsat) are readily available for many regions. Our methods are very flexible and can be applied on any region.

  3. Antimicrobial compounds from mangrove plants: A pharmaceutical prospective.

    PubMed

    Patra, Jayanta Kumar; Mohanta, Yugal Kishore

    2014-04-01

    Mangroves are salt-tolerant forest ecosystem that extends between tropical and subtropical intertidal regions of the world. Mangroves are biochemically unique vegetation that produce wide array of natural products with immense medicinal potential. These plants are the most valuable resources and provide economic and ecological benefits to the coastal people. Natural products from these plants are of great interest as they provide innumerable direct and indirect benefits to human beings for the discovery of novel antimicrobial and other bioactive compounds. They possess active metabolites with some novel chemical structures that belong to diverse chemical classes such as alkaloids, phenol, steroids, terpenoids and tannins. Several mangrove species have been used in traditional medicine or have few applications as insecticide and pesticide. To date, several mangroves, and their associated species and solvent extracts are screened for antimicrobial activity along with the presence of potent bioactive compounds. The present article emphasizes and creates awareness about the potential mangrove plants and their associates as a source of biologically active compounds with potent antimicrobial properties. This paper also elaborates the mechanisms of action and various methods for screening of antimicrobial compounds.

  4. Small RNA transcriptomes of mangroves evolve adaptively in extreme environments.

    PubMed

    Wen, Ming; Lin, Xingqin; Xie, Munan; Wang, Yushuai; Shen, Xu; Liufu, Zhongqi; Wu, Chung-I; Shi, Suhua; Tang, Tian

    2016-01-01

    MicroRNAs (miRNAs) and endogenous small interfering RNAs (siRNAs) are key players in plant stress responses. Here, we present the sRNA transcriptomes of mangroves Bruguiera gymnorrhiza and Kandelia candel. Comparative computational analyses and target predictions revealed that mangroves exhibit distinct sRNA regulatory networks that differ from those of glycophytes. A total of 32 known and three novel miRNA families were identified. Conserved and mangrove-specific miRNA targets were predicted; the latter were widely involved in stress responses. The known miRNAs showed differential expression between the mangroves and glycophytes, reminiscent of the adaptive stress-responsive changes in Arabidopsis. B. gymnorrhiza possessed highly abundant but less conserved TAS3 trans-acting siRNAs (tasiRNAs) in addition to tasiR-ARFs, with expanded potential targets. Our results indicate that the evolutionary alteration of sRNA expression levels and the rewiring of sRNA-regulatory networks are important mechanisms underlying stress adaptation. We also identified sRNAs that are involved in salt and/or drought tolerance and nutrient homeostasis as possible contributors to mangrove success in stressful environments.

  5. How to catch the patch? A dendrometer study of the radial increment through successive cambia in the mangrove Avicennia

    PubMed Central

    Robert, Elisabeth M. R.; Jambia, Abudhabi H.; Schmitz, Nele; De Ryck, Dennis J. R.; De Mey, Johan; Kairo, James G.; Dahdouh-Guebas, Farid; Beeckman, Hans; Koedam, Nico

    2014-01-01

    Background and Aims Successive vascular cambia are involved in the secondary growth of at least 200 woody species from >30 plant families. In the mangrove Avicennia these successive cambia are organized in patches, creating stems with non-concentric xylem tissue surrounded by internal phloem tissue. Little is known about radial growth and tree stem dynamics in trees with this type of anatomy. This study aims to (1) clarify the process of secondary growth of Avicennia trees by studying its patchiness; and (2) study the radial increment of Avicennia stems, both temporary and permanent, in relation to local climatic and environmental conditions. A test is made of the hypothesis that patchy radial growth and stem dynamics enable Avicennia trees to better survive conditions of extreme physiological drought. Methods Stem variations were monitored by automatic point dendrometers at four different positions around and along the stem of two Avicennia marina trees in the mangrove forest of Gazi Bay (Kenya) during 1 year. Key Results Patchiness was found in the radial growth and shrinkage and swelling patterns of Avicennia stems. It was, however, potentially rather than systematically present, i.e. stems reacted either concentrically or patchily to environment triggers, and it was fresh water availability and not tidal inundation that affected radial increment. Conclusions It is concluded that the ability to develop successive cambia in a patchy way enables Avicennia trees to adapt to changes in the prevailing environmental conditions, enhancing its survival in the highly dynamic mangrove environment. Limited water could be used in a more directive way, investing all the attainable resources in only some locations of the tree stem so that at least at these locations there is enough water to, for example, overcome vessel embolisms or create new cells. As these locations change with time, the overall functioning of the tree can be maintained. PMID:24510216

  6. Regeneration of Rhizophora mangle in a Caribbean mangrove forest: interacting effects of canopy disturbance and a stem-boring beetle.

    PubMed

    Sousa, Wayne P; Quek, Swee P; Mitchell, Betsy J

    2003-11-01

    Current theory predicts that in low-density, seed-limited plant populations, seed predation will be more important than competition in determining the number of individuals that reach maturity. However, when plant density is high, competition for microsites suitable for establishment and growth is expected to have a relatively greater effect. This dichotomous perspective does not account for situations in which the risk of seed predation differs inside versus outside recruitment microsites. We report the results of a field experiment and sampling studies that demonstrate such an interaction between microsite quality and the risk of propagule predation in mangrove forests on the Caribbean coast of Panama, where it appears to play a key role in shaping the demography and dynamics of the mangrove, Rhizophora mangle. Rhizophora's water-borne propagules establish wherever they strand, but long-term sampling revealed that only those that do so in or near lightning-created canopy gaps survive and grow to maturity. These microsites afford better growth conditions than the surrounding understory and, as importantly, provide a refuge from predation by the scolytid beetle, Coccotrypes rhizophorae. This refuge effect was confirmed with a field experiment in which Rhizophora seedlings were planted at different positions relative to gap edges, from 5 m inside to 20 m outside the gap. Mortality due to beetle attack increased linearly from an average of 10% inside a gap to 72% at 20 m into the forest. The interaction between canopy disturbance and propagule predation may be having a large impact on the composition of our study forests. Being shade-tolerant, Rhizophora seedlings that escape or survive beetle attack can persist in the understory for years. However, the high rate of beetle-induced mortality effectively eliminates the contribution of advance regeneration by Rhizophora saplings to gap succession. This may explain why the shade-intolerant mangrove, Laguncularia racemosa

  7. Geomorphic settings of mangrove ecosystem in South Andaman Island: A geospatial approach

    NASA Astrophysics Data System (ADS)

    Yuvaraj, E.; Dharanirajan, K.; Jayakumar, S.; Saravanan

    2014-12-01

    Mangroves are habitats in the coasts of tropics and subtropics, hence the geomorphology of the coast prevails in both the ocean and the land processes. To study the geomorphic setting of mangroves, it is necessary to explore both the topography of the land and the bathymetry of the sea. In this study, the geomorphic setting of mangroves in the South Andaman Island has been studied in detail using remote sensing and GIS technology. The ortho-rectified IRS satellite image was used to identify and to map the mangroves and the associated features using the visual interpretation technique. Using the GIS technique, topographic and bathymetric DEMs (Digital Elevation Models) were created to understand the geomorphology and its influence on the mangrove ecosystem. This DEM was interpreted with mangrove distribution and its associated features to create the DTM (Digital Terrain Model) of the mangrove ecosystem. Topography and bathymetry of the coast result in three dominant features like rivers, tides and waves, which play a role in shaping the geomorphic settings of mangroves, which are classified into five major types. In this study, it is identified that all the five categories of major geomorphic settings of the mangrove community exist in the south Andaman. In the field surveys, ground truth of topographic elevation, mangrove species, and associated coastal land cover features were identified and confirmed in these geomorphic settings. It is concluded that topography and bathymetry settings of the island play an indispensable role in this fragile mangrove ecosystem.

  8. Rates and drivers of mangrove deforestation in Southeast Asia, 2000-2012.

    PubMed

    Richards, Daniel R; Friess, Daniel A

    2016-01-12

    The mangrove forests of Southeast Asia are highly biodiverse and provide multiple ecosystem services upon which millions of people depend. Mangroves enhance fisheries and coastal protection, and store among the highest densities of carbon of any ecosystem globally. Mangrove forests have experienced extensive deforestation owing to global demand for commodities, and previous studies have identified the expansion of aquaculture as largely responsible. The proportional conversion of mangroves to different land use types has not been systematically quantified across Southeast Asia, however, particularly in recent years. In this study we apply a combined geographic information system and remote sensing method to quantify the key proximate drivers (i.e., replacement land uses) of mangrove deforestation in Southeast Asia between 2000 and 2012. Mangrove forests were lost at an average rate of 0.18% per year, which is lower than previously published estimates. In total, more than 100,000 ha of mangroves were removed during the study period, with aquaculture accounting for 30% of this total forest change. The rapid expansion of rice agriculture in Myanmar, and the sustained conversion of mangroves to oil palm plantations in Malaysia and Indonesia, are identified as additional increasing and under-recognized threats to mangrove ecosystems. Our study highlights frontiers of mangrove deforestation in the border states of Myanmar, on Borneo, and in Indonesian Papua. To implement policies that conserve mangrove forests across Southeast Asia, it is essential to consider the national and subnational variation in the land uses that follow deforestation. PMID:26712025

  9. Rates and drivers of mangrove deforestation in Southeast Asia, 2000-2012.

    PubMed

    Richards, Daniel R; Friess, Daniel A

    2016-01-12

    The mangrove forests of Southeast Asia are highly biodiverse and provide multiple ecosystem services upon which millions of people depend. Mangroves enhance fisheries and coastal protection, and store among the highest densities of carbon of any ecosystem globally. Mangrove forests have experienced extensive deforestation owing to global demand for commodities, and previous studies have identified the expansion of aquaculture as largely responsible. The proportional conversion of mangroves to different land use types has not been systematically quantified across Southeast Asia, however, particularly in recent years. In this study we apply a combined geographic information system and remote sensing method to quantify the key proximate drivers (i.e., replacement land uses) of mangrove deforestation in Southeast Asia between 2000 and 2012. Mangrove forests were lost at an average rate of 0.18% per year, which is lower than previously published estimates. In total, more than 100,000 ha of mangroves were removed during the study period, with aquaculture accounting for 30% of this total forest change. The rapid expansion of rice agriculture in Myanmar, and the sustained conversion of mangroves to oil palm plantations in Malaysia and Indonesia, are identified as additional increasing and under-recognized threats to mangrove ecosystems. Our study highlights frontiers of mangrove deforestation in the border states of Myanmar, on Borneo, and in Indonesian Papua. To implement policies that conserve mangrove forests across Southeast Asia, it is essential to consider the national and subnational variation in the land uses that follow deforestation.

  10. Rates and drivers of mangrove deforestation in Southeast Asia, 2000–2012

    PubMed Central

    Richards, Daniel R.; Friess, Daniel A.

    2016-01-01

    The mangrove forests of Southeast Asia are highly biodiverse and provide multiple ecosystem services upon which millions of people depend. Mangroves enhance fisheries and coastal protection, and store among the highest densities of carbon of any ecosystem globally. Mangrove forests have experienced extensive deforestation owing to global demand for commodities, and previous studies have identified the expansion of aquaculture as largely responsible. The proportional conversion of mangroves to different land use types has not been systematically quantified across Southeast Asia, however, particularly in recent years. In this study we apply a combined geographic information system and remote sensing method to quantify the key proximate drivers (i.e., replacement land uses) of mangrove deforestation in Southeast Asia between 2000 and 2012. Mangrove forests were lost at an average rate of 0.18% per year, which is lower than previously published estimates. In total, more than 100,000 ha of mangroves were removed during the study period, with aquaculture accounting for 30% of this total forest change. The rapid expansion of rice agriculture in Myanmar, and the sustained conversion of mangroves to oil palm plantations in Malaysia and Indonesia, are identified as additional increasing and under-recognized threats to mangrove ecosystems. Our study highlights frontiers of mangrove deforestation in the border states of Myanmar, on Borneo, and in Indonesian Papua. To implement policies that conserve mangrove forests across Southeast Asia, it is essential to consider the national and subnational variation in the land uses that follow deforestation. PMID:26712025

  11. Mangroves protected villages and reduced death toll during Indian super cyclone

    PubMed Central

    Das, Saudamini; Vincent, Jeffrey R.

    2009-01-01

    Protection against coastal disasters has been identified as an important service of mangrove ecosystems. Empirical studies on this service have been criticized, however, for using small samples and inadequately controlling for confounding factors. We used data on several hundred villages to test the impact of mangroves on human deaths during a 1999 super cyclone that struck Orissa, India. We found that villages with wider mangroves between them and the coast experienced significantly fewer deaths than ones with narrower or no mangroves. This finding was robust to the inclusion of a wide range of other variables to our statistical model, including controls for the historical extent of mangroves. Although mangroves evidently saved fewer lives than an early warning issued by the government, the retention of remaining mangroves in Orissa is economically justified even without considering the many benefits they provide to human society besides storm-protection services. PMID:19380735

  12. Damage and recovery assessment of the Philippines' mangroves following Super Typhoon Haiyan.

    PubMed

    Long, Jordan; Giri, Chandra; Primavera, Jurgenne; Trivedi, Mandar

    2016-08-30

    We quantified mangrove disturbance resulting from Super Typhoon Haiyan using a remote sensing approach. Mangrove areas were mapped prior to Haiyan using 30m Landsat imagery and a supervised decision-tree classification. A time sequence of 250m eMODIS data was used to monitor mangrove condition prior to, and following, Haiyan. Based on differences in eMODIS NDVI observations before and after the storm, we classified mangrove into three damage level categories: minimal, moderate, or severe. Mangrove damage in terms of extent and severity was greatest where Haiyan first made landfall on Eastern Samar and Western Samar provinces and lessened westward corresponding with decreasing storm intensity as Haiyan tracked from east to west across the Visayas region of the Philippines. However, within 18months following Haiyan, mangrove areas classified as severely, moderately, and minimally damaged decreased by 90%, 81%, and 57%, respectively, indicating mangroves resilience to powerful typhoons. PMID:27394635

  13. Oil spill impacts on mangroves: Recommendations for operational planning and action based on a global review.

    PubMed

    Duke, Norman C

    2016-08-30

    Mangrove tidal wetland habitats are recognised as highly vulnerable to large and chronic oil spills. This review of current literature and public databases covers the last 6 decades, summarising global data on oil spill incidents affecting, or likely to have affected, mangrove habitat. Over this period, there have been at least 238 notable oil spills along mangrove shorelines worldwide. In total, at least 5.5milliontonnes of oil has been released into mangrove-lined, coastal waters, oiling possibly up to around 1.94millionha of mangrove habitat, and killing at least 126,000ha of mangrove vegetation since 1958. However, there were assessment limitations with incomplete and unavailable data, as well as unequal coverage across world regions. To redress the gaps described here in reporting on oil spill impacts on mangroves and their recovery worldwide, a number of recommendations and suggestions are made for refreshing and updating standard operational procedures for responders, managers and researchers alike.

  14. Mangroves protected villages and reduced death toll during Indian super cyclone.

    PubMed

    Das, Saudamini; Vincent, Jeffrey R

    2009-05-01

    Protection against coastal disasters has been identified as an important service of mangrove ecosystems. Empirical studies on this service have been criticized, however, for using small samples and inadequately controlling for confounding factors. We used data on several hundred villages to test the impact of mangroves on human deaths during a 1999 super cyclone that struck Orissa, India. We found that villages with wider mangroves between them and the coast experienced significantly fewer deaths than ones with narrower or no mangroves. This finding was robust to the inclusion of a wide range of other variables to our statistical model, including controls for the historical extent of mangroves. Although mangroves evidently saved fewer lives than an early warning issued by the government, the retention of remaining mangroves in Orissa is economically justified even without considering the many benefits they provide to human society besides storm-protection services.

  15. Oil spill impacts on mangroves: Recommendations for operational planning and action based on a global review.

    PubMed

    Duke, Norman C

    2016-08-30

    Mangrove tidal wetland habitats are recognised as highly vulnerable to large and chronic oil spills. This review of current literature and public databases covers the last 6 decades, summarising global data on oil spill incidents affecting, or likely to have affected, mangrove habitat. Over this period, there have been at least 238 notable oil spills along mangrove shorelines worldwide. In total, at least 5.5milliontonnes of oil has been released into mangrove-lined, coastal waters, oiling possibly up to around 1.94millionha of mangrove habitat, and killing at least 126,000ha of mangrove vegetation since 1958. However, there were assessment limitations with incomplete and unavailable data, as well as unequal coverage across world regions. To redress the gaps described here in reporting on oil spill impacts on mangroves and their recovery worldwide, a number of recommendations and suggestions are made for refreshing and updating standard operational procedures for responders, managers and researchers alike. PMID:27373945

  16. Damage and recovery assessment of the Philippines' mangroves following Super Typhoon Haiyan.

    PubMed

    Long, Jordan; Giri, Chandra; Primavera, Jurgenne; Trivedi, Mandar

    2016-08-30

    We quantified mangrove disturbance resulting from Super Typhoon Haiyan using a remote sensing approach. Mangrove areas were mapped prior to Haiyan using 30m Landsat imagery and a supervised decision-tree classification. A time sequence of 250m eMODIS data was used to monitor mangrove condition prior to, and following, Haiyan. Based on differences in eMODIS NDVI observations before and after the storm, we classified mangrove into three damage level categories: minimal, moderate, or severe. Mangrove damage in terms of extent and severity was greatest where Haiyan first made landfall on Eastern Samar and Western Samar provinces and lessened westward corresponding with decreasing storm intensity as Haiyan tracked from east to west across the Visayas region of the Philippines. However, within 18months following Haiyan, mangrove areas classified as severely, moderately, and minimally damaged decreased by 90%, 81%, and 57%, respectively, indicating mangroves resilience to powerful typhoons.

  17. Material flux in mangrove forest based on the field observation.

    NASA Astrophysics Data System (ADS)

    Terada, K.; Koibuchi, Y.; Isobe, M.

    2008-12-01

    Mangrove ecosystems play important roles in conservation of seashore lines and spawning and nursery of aquatic creatures. It is important to understand nutrient budgets and links between human activities and their effects on mangrove ecosystems. However, we have less knowledge about mangrove ecosystems than that about many other ecosystems. To quantify total material balances in the estuary centered in mangrove forest, we have measured nutrient cycling and CH4 and CO2 gas fluxes in Fukido mangrove creek, Ishigaki island, Okinawa, Japan. It was conducted over tidal cycles from 2006 to 2008. To understand the difference between weather conditions, we investigated on both of rainy day and fine day. Water budget in the river was controlled by tidal exchange at estuary and the input budget from upriver was not dominant for the total budget even if it"fs rain"DFrom estimation of suspended solids (SS) budgets, SS was flowed in the river from upriver significantly on rainy day (more than 5 times inflow of fine day). The amount of SS accumulation in mangrove forest on rainy day (316 kg/day) was about 10 times amount of fine day. Total nitrogen (T-N) and total phosphorus (T-P) budgets also showed accumulation in mangrove. The outflow of T-P to coastal area on rainy day was 0.046 kgPO4/day and nearly equal to fine day. In contrast, T-N outflow to coastal on rainy day (0.58 kgN/day) was about 100 times of fine day. T-N budget showed different behavior from T-P. Ammonia nitrogen (NH4+-N) was dissolved from mangrove forest (~3.83 kgN/day by the nutrient dissolution experiments) and flowed out to estuary under certain conditions. In addition"Cconcentrations of total organic carbon (TOC) in mangrove creeks increased on fine days (11.2~15.5 mgC/L) and decreased on rainy days(1.8~4.9 mgC/L). It suggested the TOC dissolution to creek water from mangrove carbon-rich sediments and dilution effects by rain. Continuous measurements of gas fluxes showed that the CH4 and CO2 emissions from

  18. [Mangrove characterization of Central America with remote sensors].

    PubMed

    Lizano, O G; Amador, J; Soto, R

    2001-12-01

    Satellite images were used to study the mangrove distribution patterns in two different climatic regions of Central America: Gulf of Fonseca in Honduras-El Salvador and Sierpe-Térraba in Costa Rica. The Gulf of Fonseca has higher temperature and solar radiation, and lower precipitation, which can explain the higher structural development and species mixing of the Sierpe-Térraba mangrove. In the latter the transition between species or between heights in the same species is clear. The automatic classification made by the Geographic Information System (IDRISI) fits well the field mangrove distribution, but it was necessary to regroup some subdivisions that represent the same land use as identified by transects and an aerial video. Mixed species and clouds produced less satisfactory results in Sierpe-Térraba indicating a need for better satellite image resolution.

  19. [Caloric values and ash contents of some mangrove woods].

    PubMed

    Lin, Y; Lin, P; Wang, T

    2000-04-01

    The caloric values and ash contents of some mangrove woods in Dongzhai Harbor Mangrove Forest Reserve of Hainan Province were determined in Summer, and the changes of the caloric value of Kandelia candel woods at different latitudes were studied. The ash content of mangrove woods was low, ranging from 2.43% to 5.17%; and their gross and ash-free caloric values ranged from 17.23 kJ.g-1 to 19.21 kJ.g-1 and from 17.70 kJ.g-1 to 20.10 kJ.g-1, respectively. Sonneratia apetala wood had the lowest gross and ash-free caloric values. The caloric value of Kandelia candel wood decreased with increasing latitude in Summer.

  20. [Construction of large fragment metagenome library of natural mangrove soil].

    PubMed

    Jiang, Yun-Xia; Zheng, Tian-Ling

    2007-11-01

    Applying our optimized direct extraction method, the percentage of large fragment DNA in the total extracted mangrove soil DNA was significant increased. The large fragment metagenome library derived from natural mangrove soil over four seasons was successfully constructed by the optimized DNA extraction and electro elution purification method. All of the clones had recombinant Cosmids and each differed in their fragment profiles when Cosmid DNA was extracted from 12 randomly picked colonies and digested with BamHI. The average insert size for this library was larger than 35 kbp. This culturing-independent library at least encompassed 335 Mbp valuable genetic information of mangrove soil microbes. It allowed mining of valuable intertidal microbial resource to become a reality. It is a recommended method for those researchers who have still not circumvented the large insert environmental libraries or for those beginning research in this field, so as to avoid them attempting repetitive, fussy work.

  1. Interannual and cyclone-driven variability in phytoplankton communities of a tropical coastal lagoon.

    PubMed

    Srichandan, Suchismita; Kim, Ji Yoon; Kumar, Abhishek; Mishra, Deepak R; Bhadury, Punyasloke; Muduli, Pradipta R; Pattnaik, Ajit K; Rastogi, Gurdeep

    2015-12-15

    One of the main challenges in phytoplankton ecology is to understand their variability at different spatiotemporal scales. We investigated the interannual and cyclone-derived variability in phytoplankton communities of Chilika, the largest tropical coastal lagoon in Asia and the underlying mechanisms in relation to environmental forcing. Between July 2012 and June 2013, Cyanophyta were most prolific in freshwater northern region of the lagoon. A category-5 very severe cyclonic storm (VSCS) Phailin struck the lagoon on 12th October 2013 and introduced additional variability into the hydrology and phytoplankton communities. Freshwater Cyanophyta further expanded their territory and occupied the northern as well as central region of the lagoon. Satellite remote sensing imagery revealed that the phytoplankton biomass did not change much due to high turbidity prevailing in the lagoon after Phailin. Modeling analysis of species-salinity relationship identified specific responses of phytoplankton taxa to the different salinity regime of lagoon.

  2. Interannual and cyclone-driven variability in phytoplankton communities of a tropical coastal lagoon.

    PubMed

    Srichandan, Suchismita; Kim, Ji Yoon; Kumar, Abhishek; Mishra, Deepak R; Bhadury, Punyasloke; Muduli, Pradipta R; Pattnaik, Ajit K; Rastogi, Gurdeep

    2015-12-15

    One of the main challenges in phytoplankton ecology is to understand their variability at different spatiotemporal scales. We investigated the interannual and cyclone-derived variability in phytoplankton communities of Chilika, the largest tropical coastal lagoon in Asia and the underlying mechanisms in relation to environmental forcing. Between July 2012 and June 2013, Cyanophyta were most prolific in freshwater northern region of the lagoon. A category-5 very severe cyclonic storm (VSCS) Phailin struck the lagoon on 12th October 2013 and introduced additional variability into the hydrology and phytoplankton communities. Freshwater Cyanophyta further expanded their territory and occupied the northern as well as central region of the lagoon. Satellite remote sensing imagery revealed that the phytoplankton biomass did not change much due to high turbidity prevailing in the lagoon after Phailin. Modeling analysis of species-salinity relationship identified specific responses of phytoplankton taxa to the different salinity regime of lagoon. PMID:26611863

  3. Assessment of the environmental impact of artificial effluent lagoon in Jiayuguan City of China.

    PubMed

    Pei, Yuan-sheng; Luan, Zhao-kun; Barber, C; Williamson, D

    2003-07-01

    An artificial effluent lagoon for storing wastewater were excavated in Jiayuguan City since 1994. As a part of a demonstration project of Sino-Australia cooperation, an assessment of the environmental impact of the lagoon was carried out. The assessment was based on field and laboratory tests and predictive model. The main impacts from the lagoon site are likely to be on the groundwater system, and, to a lesser extent, on ambient air quality in the vicinity. Currently it is expected that groundwater is being polluted with effluent from the effluent lagoon. Air pollution (odor nuisance) is mainly caused by untreated effluent in the irrigation channel. The impact of high total dissolved salt (TDS) on groundwater is likely to be significant in the long run if the lagoon is continuously used. There is, consequently, no likelihood of contamination of surface water system, particularly of the city water supply system, from infiltration of effluent at the lagoon.

  4. Photosynthetic pigments of Zoster a noltii and Ruppia cirrhosa in some Albanian lagoons

    NASA Astrophysics Data System (ADS)

    Ylli, Arjana; Babani, Fatbardha; Stamo, Iliriana

    2010-01-01

    In the coastal lagoons of Adriatic Sea Zostera noltii and Ruppia cirrhosa are plants with seeds and flowers, that colonizes the sandy bottom of lagoons. They are capable to produce oxygen with very weak light. Characterization of photosynthetic pigments of eelgrass Zostera noltii and Ruppia cirrhosa, were performed during the period 2002-2008 in some Adriatic lagoons: Kune-Vaini, Patog, Karavasta and Narta. Dynamics of chlorophylls and carotenoids during the vegetation period of these plants were characterized. As a result, the chlorophyll content of Zoostera noltii taken from the Kune- Vain lagoon is higher than at plants collected from the other lagoons. The photosynthetic pigment content of the Zostera noltii plants is higher than of Ruppia cirrhosa. The differences on the distribution of these species in the analyzed lagoons are represented in this presentation.

  5. Spatial and temporal distribution of cyanobacteria in Batticaloa Lagoon.

    PubMed

    Harris, Jalaldeen Mohamed; Vinobaba, Periyathamby; Kularatne, Ranil Kavindra Asela; Ellawala Kankanamge, Champika

    2016-09-01

    The necessity to understand the relationship between cyanobacterial species abundance and water quality variations in coastal lagoons is crucial to develop strategies to prevent further cyanobacterial proliferation. This paper evaluates the relationship between water quality variations on the distribution of cyanobacteria during a 12-month period in Batticaloa Lagoon (Sri Lanka) using Redundancy analysis and Pearson correlations. Drastic variations in pH, temperature, salinity, dissolved oxygen (DO) and total phosphorus (TP) levels were reported, but not turbidity and NO3(-). This brackish waterbody is hypereutrophic (TP levels>0.1mg/L). The cyanobacterial community contained 13 genera and 22 species. NO3(-), TP and turbidity levels positively influenced cyanobacterial abundance during all seasons indicating that nutrient (largely phosphorus) and sediment entry control is highly crucial along with periodic monitoring of cyanobacterial growth. PMID:27593288

  6. The performance of biomass-based AMBI in lagoonal ecosystems.

    PubMed

    Mistri, Michele; Munari, Cristina

    2015-10-15

    We studied the performance of the AZTI Marine Biotic Index AMBI manipulating input data collected from lagoonal ecosystems. Our data set consisted of macrofaunal abundance and biomass counts gathered at a variety of sites at which the disturbance status was known. Input data were also manipulated using a set of transformations of increasing severity. Biotic indices were calculated using raw and transformed abundance, biomass and production. Among the three categories of AMBI-based indices, medium transformation of data gave the highest correlation with pressures. However, increasing the severity of transformation generally resulted in a decrease of the correlation with environmental factors. The relative importance of ecological groups changed when using abundance or biomass, sometimes leading to an improved ecological status classification. Being biomass and production more ecologically relevant than abundance, using them to derive AMBI-based new indices seems intriguing, at least in lagoonal waters, where the community is naturally disturbed and dominated by opportunists. PMID:26219686

  7. An integrated physical and biological model for anaerobic lagoons.

    PubMed

    Wu, Binxin; Chen, Zhenbin

    2011-04-01

    A computational fluid dynamics (CFD) model that integrates physical and biological processes for anaerobic lagoons is presented. In the model development, turbulence is represented using a transition k-ω model, heat conduction and solar radiation are included in the thermal model, biological oxygen demand (BOD) reduction is characterized by first-order kinetics, and methane yield rate is expressed as a linear function of temperature. A test of the model applicability is conducted in a covered lagoon digester operated under tropical climate conditions. The commercial CFD software, ANSYS-Fluent, is employed to solve the integrated model. The simulation procedures include solving fluid flow and heat transfer, predicting local resident time based on the converged flow fields, and calculating the BOD reduction and methane production. The simulated results show that monthly methane production varies insignificantly, but the time to achieve a 99% BOD reduction in January is much longer than that in July.

  8. Nitrate ammonification in mangrove soils: a hidden source of nitrite?

    PubMed Central

    Balk, Melike; Laverman, Anniet M.; Keuskamp, Joost A.; Laanbroek, Hendrikus J.

    2015-01-01

    Nitrate reduction is considered to be a minor microbial pathway in the oxidation of mangrove-derived organic matter due to a limited supply of nitrate in mangrove soils. At a limited availability of this electron acceptor compared to the supply of degradable carbon, nitrate ammonification is thought to be the preferential pathway of nitrate reduction. Mangrove forest mutually differ in their productivity, which may lead to different available carbon to nitrate ratios in their soil. Hence, nitrate ammonification is expected to be of more importance in high- compared to low-productive forests. The hypothesis was tested in flow-through reactors that contain undisturbed mangrove soils from high-productive Avicennia germinans and Rhizophora mangle forests in Florida and low-productive Avicennia marina forests in Saudi Arabia. Nitrate was undetectable in the soils from both regions. It was assumed that a legacy of nitrate ammonification would be reflected by a higher ammonium production from these soils upon the addition of nitrate. Unexpectedly, the soils from the low-productive forests in Saudi Arabia produced considerably more ammonium than the soils from the high-productive forests in Florida. Hence, other environmental factors than productivity must govern the selection of nitrate ammonification or denitrification. A rather intriguing observation was the 1:1 production of nitrite and ammonium during the consumption of nitrate, more or less independent from sampling region, location, sampling depth, mangrove species and from the absence or presence of additional degradable carbon. This 1:1 ratio points to a coupled production of ammonium and nitrite by one group of nitrate-reducing microorganisms. Such a production of nitrite will be hidden by the presence of active nitrite-reducing microorganisms under the nitrate-limited conditions of most mangrove forest soils. PMID:25784903

  9. Nitrate ammonification in mangrove soils: a hidden source of nitrite?

    PubMed

    Balk, Melike; Laverman, Anniet M; Keuskamp, Joost A; Laanbroek, Hendrikus J

    2015-01-01

    Nitrate reduction is considered to be a minor microbial pathway in the oxidation of mangrove-derived organic matter due to a limited supply of nitrate in mangrove soils. At a limited availability of this electron acceptor compared to the supply of degradable carbon, nitrate ammonification is thought to be the preferential pathway of nitrate reduction. Mangrove forest mutually differ in their productivity, which may lead to different available carbon to nitrate ratios in their soil. Hence, nitrate ammonification is expected to be of more importance in high- compared to low-productive forests. The hypothesis was tested in flow-through reactors that contain undisturbed mangrove soils from high-productive Avicennia germinans and Rhizophora mangle forests in Florida and low-productive Avicennia marina forests in Saudi Arabia. Nitrate was undetectable in the soils from both regions. It was assumed that a legacy of nitrate ammonification would be reflected by a higher ammonium production from these soils upon the addition of nitrate. Unexpectedly, the soils from the low-productive forests in Saudi Arabia produced considerably more ammonium than the soils from the high-productive forests in Florida. Hence, other environmental factors than productivity must govern the selection of nitrate ammonification or denitrification. A rather intriguing observation was the 1:1 production of nitrite and ammonium during the consumption of nitrate, more or less independent from sampling region, location, sampling depth, mangrove species and from the absence or presence of additional degradable carbon. This 1:1 ratio points to a coupled production of ammonium and nitrite by one group of nitrate-reducing microorganisms. Such a production of nitrite will be hidden by the presence of active nitrite-reducing microorganisms under the nitrate-limited conditions of most mangrove forest soils.

  10. Effects of nutrient enrichment on mangrove leaf litter decomposition.

    PubMed

    Keuskamp, Joost A; Hefting, Mariet M; Dingemans, Bas J J; Verhoeven, Jos T A; Feller, Ilka C

    2015-03-01

    Nutrient enrichment of mangroves, a common phenomenon along densely populated coastlines, may negatively affect mangrove ecosystems by modifying internal carbon and nutrient cycling. The decomposition of litter exerts a strong influence on these processes and is potentially modified by eutrophication. This study describes effects of N and P enrichment on litter decomposition rate and mineralisation/immobilisation patterns. By making use of reciprocal litter transplantation experiments among fertiliser treatments, it was tested if nutrient addition primarily acts on the primary producers (i.e. changes in litter quantity and quality) or on the microbial decomposers (i.e. changes in nutrient limitation for decomposition). Measurements were done in two mangrove forests where primary production was either limited by N or by P, which had been subject to at least 5 years of experimental N and P fertilisation. Results of this study indicated that decomposers were always N-limited regardless of the limitation of the primary producers. This leads to a differential nutrient limitation between decomposers and primary producers in sites where mangrove production was P-limited. In these sites, fertilisation with P caused litter quality to change, resulting in a higher decomposition rate. This study shows that direct effects of fertilisation on decomposition through an effect on decomposer nutrient availability might be non-significant, while the indirect effects through modifying litter quality might be quite substantial in mangroves. Our results show no indication that eutrophication increases decomposition without stimulating primary production. Therefore we do not expect a decline in carbon sequestration as a result of eutrophication of mangrove ecosystems.

  11. Woody Debris in the mangrove forests of South Florida

    USGS Publications Warehouse

    Krauss, K.W.; Doyle, T.W.; Twilley, R.R.; Smith, T. J.; Whelan, K.R.T.; Sullivan, J.K.

    2005-01-01

    Woody debris is abundant in hurricane-impacted forests. With a major hurricane affecting South Florida mangroves approximately every 20 yr, carbon storage and nutrient retention may be influenced greatly by woody debris dynamics. In addition, woody debris can influence seedling regeneration in mangrove swamps by trapping propagules and enhancing seedling growth potential. Here, we report on line-intercept woody debris surveys conducted in mangrove wetlands of South Florida 9-10 yr after the passage of Hurricane Andrew. The total volume of woody debris for all sites combined was estimated at 67 m 3/ha and varied from 13 to 181 m3/ha depending upon differences in forest height, proximity to the storm, and maximum estimated wind velocities. Large volumes of woody debris were found in the eyewall region of the hurricane, with a volume of 132 m3/ha and a projected woody debris biomass of approximately 36 t/ha. Approximately half of the woody debris biomass averaged across all sites was associated as small twigs and branches (fine woody debris), since coarse woody debris >7.5 cm felled during Hurricane Andrew was fairly well decomposed. Much of the small debris is likely to be associated with post-hurricane forest dynamics. Hurricanes are responsible for large amounts of damage to mangrove ecosystems, and components of associated downed wood may provide a relative index of disturbance for mangrove forests. Here, we suggest that a fine:coarse woody debris ratio ???0.5 is suggestive of a recent disturbance in mangrove wetlands, although additional research is needed to corroborate such findings.

  12. A new sampler for stratified lagoon chemical and microbiological assessments.

    PubMed

    McLaughlin, M R; Brooks, J P; Adeli, A

    2014-07-01

    A sampler was needed for a spatial and temporal study of microbial and chemical stratification in a large swine manure lagoon that was known to contain zoonotic bacteria. Conventional samplers were limited to collections of surface water samples near the bank or required a manned boat. A new sampler was developed to allow simultaneous collection of multiple samples at different depths, up to 2.3 m, without a manned boat. The sampler was tethered for stability, used remote control (RC) for sample collection, and accommodated rapid replacement of sterile tubing modules and sample containers. The sampler comprised a PVC pontoon with acrylic deck and watertight enclosures, for a 12 VDC gearmotor, to operate the collection module, and vacuum system, to draw samples into reusable autoclavable tubing and 250-mL bottles. Although designed primarily for water samples, the sampler was easily modified to collect sludge. The sampler held a stable position during deployment, created minimal disturbance in the water column, and was readily cleaned and sanitized for transport. The sampler was field tested initially in a shallow fresh water lake and subsequently in a swine manure treatment lagoon. Analyses of water samples from the lagoon tests showed that chemical and bacterial levels, pH, and EC did not differ between 0.04, 0.47, and 1.0 m depths, but some chemical and bacterial levels differed between winter and spring collections. These results demonstrated the utility of the sampler and suggested that future manure lagoon studies employ fewer or different depths and more sampling dates. PMID:24549945

  13. Numerical modeling of the Patos Lagoon coastal plume, Brazil

    NASA Astrophysics Data System (ADS)

    Marques, W. C.; Fernandes, E. H.; Monteiro, I. O.; Möller, O. O.

    2009-03-01

    The Southern Brazilian Shelf (SBS) is a freshwater-influenced region, but studies on the dynamics of coastal plumes are sparse and lack in space-time resolution. Studies on the dynamics of the Patos Lagoon plume are even more limited. The aim of this paper is to investigate the influence of the principal physical forcing for the formation and behavior of the Patos Lagoon coastal plume. The study is carried out through 3D numerical modeling experiments and empirical orthogonal function (EOF) analysis. Results showed that the amount of freshwater is the principal physical forcing controlling the plume formation. The Coriolis effect enhances the northward transport over the shelf, while the tidal effects contribute to intensify horizontal and vertical mixing, which are responsible for spreading the freshwater over the shelf. The wind effect, on the other hand, is the main mechanism controlling the behavior of the Patos Lagoon coastal plume over the inner SBS in synoptic time scales. Southeasterly and southwesterly winds contribute to the northeastward displacement of the plume, breaking the vertical stratification of the inner continental shelf. Northeasterly and northwesterly winds favor ebb conditions in the Patos Lagoon, contributing to the southwestward displacement of the plume enhancing the vertical stratification along and across-shore. The EOF analysis reveals two modes controlling the variability of the plume on the surface. The first mode (explaining 70% of the variability) is associated to the southwestward transportation of the plume due to the dominance of north quadrant winds, while the second mode (explaining 19% of the variability) is associated to the intermittent migration of the plume northeastward due to the passage of frontal systems over the area. Large scale plumes can be expected during winter and spring months, and are enhanced during El Niño events.

  14. Statistical characterization of spatiotemporal sediment dynamics in the Venice lagoon

    NASA Astrophysics Data System (ADS)

    Carniello, Luca; D'Alpaos, Andrea; Botter, Gianluca; Rinaldo, Andrea

    2016-05-01

    Characterizing the dynamics of suspended sediment is crucial when investigating the long-term evolution of tidal landscapes. Here we apply a widely tested mathematical model which describes the dynamics of cohesive and noncohesive sediments, driven by the combined effect of tidal currents and wind waves, using 1 year long time series of observed water levels and wind data from the Venice lagoon. The spatiotemporal evolution of the computed suspended sediment concentration (SSC) is analyzed on the basis of the "peak over threshold" theory. Our analysis suggests that events characterized by high SSC can be modeled as a marked Poisson process over most of the lagoon. The interarrival time between two consecutive over threshold events, the intensity of peak excesses, and the duration are found to be exponentially distributed random variables over most of tidal flats. Our study suggests that intensity and duration of over threshold events are temporally correlated, while almost no correlation exists between interarrival times and both durations and intensities. The benthic vegetation colonizing the central southern part of the Venice lagoon is found to exert a crucial role on sediment dynamics: vegetation locally decreases the frequency of significant resuspension events by affecting spatiotemporal patterns of SSCs also in adjacent areas. Spatial patterns of the mean interarrival of over threshold SSC events are found to be less heterogeneous than the corresponding patterns of mean interarrivals of over threshold bottom shear stress events because of the role of advection/dispersion processes in mixing suspended sediments within the lagoon. Implications for long-term morphodynamic modeling of tidal environments are discussed.

  15. Validation of Numerical Shallow Water Models for Tidal Lagoons

    SciTech Connect

    Eliason, D.; Bourgeois, A.

    1999-11-01

    An analytical solution is presented for the case of a stratified, tidally forced lagoon. This solution, especially its energetics, is useful for the validation of numerical shallow water models under stratified, tidally forced conditions. The utility of the analytical solution for validation is demonstrated for a simple finite difference numerical model. A comparison is presented of the energetics of the numerical and analytical solutions in terms of the convergence of model results to the analytical solution with increasing spatial and temporal resolution.

  16. Taphonomy of coral reefs from Southern Lagoon of Belize

    SciTech Connect

    Westphall, M.J.; Ginsburg, R.N.

    1985-02-01

    The Southern Lagoon of the Belize barrier complex, an area of some 600 km/sup 2/, contains a tremendous number of lagoon reefs, which range in size from patches several meters across to rhomboidal-shaped structures several kilometers in their long dimension. These lagoon reefs are remarkable because they have Holocene sediment accumulations in excess of 13 m consisting almost entirely of coral debris and lime mud and sand, and rise up to 30 m above the surrounding lagoon floor with steeply sloping sides (50-80/sup 0/), yet are totally uncemented. The reef-building biota and their corresponding deposits were studied at a representative reef, the rhomboidal complex of Channel Cay. As with many of the reefs in this area, the steeply sloping flanks of Channel Cay are covered mainly by the branched staghorn coral Acropora cervicornis and ribbonlike and platy growth of Agaricia spp. The living corals are not cemented to the substrate, but are merely intergrown. Fragmented pieces of corals accumulate with an open framework below the living community; this open framework is subsequently infilled by lime muds and sands produced mainly from bioerosion. Results from probing and coring suggest that the bafflestone fabric of coral debris and sediment extends at least 13 m into the subsurface. Radiocarbon-age estimates indicate these impressive piles of coral rubble and sediment have accumulated in the past 9000 yr (giving a minimum accumulation rate of 1.4 m/1000 yr) and illustrate the potential for significant carbonate buildups without the need for early lithification.

  17. Geoelectrical signals of geologic and hydrologic processes in a fringing reef lagoon setting

    NASA Astrophysics Data System (ADS)

    Befus, Kevin M.; Cardenas, M. Bayani; Tait, Douglas R.; Erler, Dirk V.

    2014-09-01

    Coastal groundwater may discharge into nearshore and offshore waters forced by terrestrial fluxes, controlled by local geology, and modulated by the hydrodynamics of littoral water. We investigated the electrical signature of these features with a dense, multiscale network of electrical resistivity tomography (ERT) surveys in the Muri Lagoon of Rarotonga, Cook Islands. The ERT surveys spanned from onshore to 400 m into the lagoon and used standard electrodes on land and across the foreshore, submerged electrodes in the shallow subtidal zone, and floating electrodes towed throughout the reef lagoon by a boat. ERT surveys on land mapped a typical freshwater lens underlain by a saltwater wedge, but with possible deviations from the classical model due to an adjacent tidal creek. Further inland, ERT surveys imaged a layer of lava flow deposits that is potentially a confining hydrogeologic unit; this unit was used to constrain the expected electrical resistivity of these deposits below the lagoon. ERT surveys across the intertidal zone and into the lagoon indicated fresh groundwater and porewater salinity patterns consistent with previous small-scale studies including the seaward extension of fresh groundwater pathways to the lagoon. Electrical resistivity (ER) variations in the lagoon subsurface highlighted heterogeneities in the lagoon structure that may focus submarine groundwater discharge (SGD) through previously unknown buried lava flow deposits in the lagoon. A transition to higher ER values near the reef crest is consistent with the ER signature of porosity reduction due to ongoing differential cementation of reef deposits across the lagoon. The imaged coastal hydrostratigraphic heterogeneity may thus control terrestrial and marine porewater mixing, support SGD, and provide the pathways for groundwater and the materials it transports into the lagoon. This hydrogeophysical investigation highlighted the spatial heterogeneity of submarine coastal geology and its

  18. Municipal sewage treatment: Lagoons (ponds). (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-07-01

    The bibliography contains citations concerning the treatment and storage of municipal wastewater and sewage in lagoons. Lagoon design, operation, and associated equipment for pretreatment, treatment, and storage techniques are discussed. Many citations describe the water treatment facilities of specific cities, and provide evaluations of the operations at those sites. Industrial and other non-municipal wastewater treatment lagoons are referenced in a related bibliography. (Contains 250 citations and includes a subject term index and title list.)

  19. Helminth communities in eels Anguilla anguilla from Adriatic coastal lagoons in Italy.

    PubMed

    Di Cave, D; Berrilli, F; De Liberato, C; Orecchia, P; Kennedy, C R

    2001-03-01

    The composition and diversity of the total and intestinal component and infra-communities were determined in eels Anguilla anguilla from three shallow lagoons on the Adriatic coast of Italy to determine whether the helminth communities would differ in composition and structure from those in eels from lagoons on the Tyrrhenian coast. The lagoons differed in respect of their management regimes and the extent of freshwater influx. Both freshwater and marine species of helminths were found in the eels in all three lagoons, but the freshwater component was richer in Valle Figheri. A suite of three digenean eel specialist species occurred in all three lagoons, of which any two members dominated each community. This conferred a high degree of similarity between the communities of the three lagoons. The same three species also dominated helminth communities in eels in lagoons along the Tyrrhenian coast of Italy, and compositional similarity levels were similar within and between western and eastern groups. Species richness was higher in the component communities of the eels of the Adriatic lagoons when compared to the Tyrrhenian ones, but diversity and dominance indices were of a similar order of magnitude and range. Intestinal helminth communities were richer and more diverse in two of the Adriatic lagoons because the proportion of eels with zero or one helminth species was, unusually, in the minority. It was nevertheless concluded that infracommunity structure was similar in eels from both western and eastern lagoons and that the hypothesis that it would differ in Adriatic lagoons could not be supported. The findings provide further evidence of the similarity in composition and structure of helminth communities in eels from coastal lagoons throughout Europe.

  20. Industrial waste treatment: Lagoons (ponds). (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-01-01

    The bibliography contains citations concerning the treatment and storage of wastewaters in lagoons. Lagoon design, operation, associated equipment, and pretreatment processes are discussed. Included in the references are treatment of wastewaters from breweries, tanneries, paper mills, agricultural operations, and other industrial operations. Descriptions and evaluations of specific facilities are provided. Municipal water and sewage treatment lagoons are referenced in a related bibliography. (Contains a minimum of 118 citations and includes a subject term index and title list.)

  1. Municipal sewage treatment: Lagoons (ponds). (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-11-01

    The bibliography contains citations concerning the treatment and storage of municipal wastewater and sewage in lagoons. Lagoon design, operation, and associated equipment for pretreatment, treatment, and storage techniques are discussed. Many citations describe the water treatment facilities of specific cities, and provide evaluations of the operations at those sites. Industrial and other non-municipal wastewater treatment lagoons are referenced in a related bibliography. (Contains 250 citations and includes a subject term index and title list.)

  2. Reduction of estrogenic activity of municipal wastewater by aerated lagoon treatment facilities.

    PubMed

    Bringolf, Robert B; Summerfelt, Robert C

    2003-01-01

    The estrogenic activity of municipal wastewater in aerated lagoon treatment facilities was evaluated using plasma concentrations of vitellogenin (Vtg) in male fathead minnows (Pimephales promelas). Caged fathead minnows were exposed for 10 to 12 d in three lagoons that are connected in series at each of 10 municipal wastewater treatment facilities in central Iowa, USA, during October and November 2000. Fathead minnows held in the laboratory served as unexposed controls. Pooled (n = 4-10 fish) plasma Vtg, quantified by enzyme-linked immunosorbent assay (ELISA), was 1,702 +/- 670 (mean +/- standard error [SE]) microg/ml in the first lagoons (n = 9), 0.94 +/- 0.36 microg/ml in the second lagoons (n = 10), and 0.04 +/- 0.02 microg/ml in the third lagoons (n = 8). Differences in mean fish plasma Vtg concentration among lagoons were highly significant (p < 0.001). The mean concentration of plasma Vtg in fish in the third lagoons was not significantly different (p = 0.990) from that of the control fish (0.04 +/- 0.02 microg/ml). Plasma Vtg concentrations of fish in the first lagoons were inversely correlated with wastewater retention time in the lagoons (p = 0.002, r = -0.877). Water temperatures of the final effluents during the study ranged from 9 to 12 degrees C. General treatment efficiency of lagoons has been shown to be dependent on temperature, so the potential exists for decreased removal of estrogenic activity when water temperatures are lower (e.g., winter months) than the present study. In conclusion, wastewater entering aerated lagoon systems was estrogenic to fish, but with serial passage through the lagoons, the estrogenic activity decreased to a level that was not sufficient to induce vitellogenesis in male fathead minnows in a 10- to 12-d exposure.

  3. What regulates crab predation on mangrove propagules?

    NASA Astrophysics Data System (ADS)

    Van Nedervelde, Fleur; Cannicci, Stefano; Koedam, Nico; Bosire, Jared; Dahdouh-Guebas, Farid

    2015-02-01

    Crabs play a major role in some ecosystems. To increase our knowledge about the factors that influence crab predation on propagules in mangrove forests, we performed experiments in Gazi Bay, Kenya in July 2009. We tested whether: (1) crab density influences propagule predation rate; (2) crab size influences food competition and predation rate; (3) crabs depredate at different rates according to propagule and canopy cover species; (4) vegetation density is correlated with crab density; (5) food preferences of herbivorous crabs are determined by size, shape and nutritional value. We found that (1) propagule predation rate was positively correlated to crab density. (2) Crab competitive abilities were unrelated to their size. (3) Avicennia marina propagules were consumed more quickly than Ceriops tagal except under C. tagal canopies. (4) Crab density was negatively correlated with the density of A. marina trees and pneumatophores. (5) Crabs prefer small items with a lower C:N ratio. Vegetation density influences crab density, and crab density affects propagule availability and hence vegetation recruitment rate. Consequently, the mutual relationships between vegetation and crab populations could be important for forest restoration success and management.

  4. Holocene mangrove swamps of West Africa sedimentology and soils

    NASA Astrophysics Data System (ADS)

    Marius, C.; Lucas, J.

    The mangrove swamps of West African Coast belong to the Atlantic type which is characterized by a small number of species. They colonize tidal environments which are dissected by numerous meandering tidal channels and are presently subject to a low rate of sediment accumulation. The mangrove vegetation exhibits a characteristic zonation pattern that basically reflects the adaptation of the various species to saline conditions. The typical zonation sequence is: Rhizophora racemosa (or Rh. mangle), Rh. mangle + Avicennia africana, Avicennia, flooded tanne, barren tanne, herbaceous tanne. The tannes are generated by aridic climatic conditions, heavy soil and water salt content, and are, in a way a peculiar feature of mangrove swamps in West Africa. The sediment colonized by the mangroves is relatively homogenous. Mineralogically, they are dominated by quartz and clay to which are associated halite, pyrite and jarosite. The clay suite is mainly composed of smectite and kaolinite. Smectite is predominant in the inlet areas and is replaced inland by kaolinite. Chemically, the sediments contain very low amounts of Ca, bases and trace elements. The mangrove swamp floodwaters have a chemical composition similar to that of seawater. It is dominated by sodium and chloride. Morphologically, the ripening of the soils appears with a chestnut mash colour horizon and buttery consistency in relation with the decomposition of fibrous roots of Rhizophora and also with pale yellow jarosite mottles in the top horizons of the tanne profiles due to the oxidation of pyrine. The two main properties of the mangrove soils of West Africa are acidity and salinity; the first is related to the high content of sulphur and the second to the sea influence. The acidity has to be connected mainly to the Rhizophora vegetation whose the root system is a real trap for catching the pyrites resulting from the reduction of the sulphates of sea water by the sulphate reducing bacteria, in a reduced

  5. Modeling Biological Invasion: The Case Of Dengue And Mangrove

    NASA Astrophysics Data System (ADS)

    Lye, Koh Hock; Yean, Teh Su; Ismail, Ahmad Izani Md.; DeAngelis, Donald L.

    2008-01-01

    It is well known that organism invades territory in the form of wave fronts whose characteristics are determined primarily by environmental conditions such as hydrology, salinity, climate, carrying capacity and resource. In this invited paper, we will consider two ecosystems, one comprising mosquitoes of the species Aedes aegypti that are the vector of dengue fever while the second consists of coastal ecosystem composed of mixtures of mangrove and hardwood hammocks in south Florida. Their dispersal dynamics modeled by simulations DEER and MANHAM will be discussed. Implications regarding approaches for the eradication of A. aegypti and the replanting or recovery of coastal mangrove forests will be presented.

  6. New diterpenes from a Godavari mangrove, Ceriops decandra.

    PubMed

    Wang, Hui; Li, Min-Yi; Satyanandamurty, Tirumani; Wu, Jun

    2013-05-01

    Eleven new diterpenes, named decandrins A-K (1-11), including nine abietanes (1-9) and two podocarpanes (10-11), were isolated from the barks of an Indian mangrove, Ceriops decandra, collected in the mangrove swamp of Godavari estuary, Andhra Pradesh, together with four known abietanes. The structures of these compounds were established on the basis of spectroscopic data (new compounds) or comparison with data in the literature (known compounds). This is the first report of abietane and podocarpane diterpenoids from C. decandra.

  7. Saline landfill leachate disposal in facultative lagoons for wastewater treatment.

    PubMed

    Orta de Velasquez, M T; Monje-Ramirez, I; Yañez Noguez, I

    2012-01-01

    This study was carried out to determine the effect of disposing of saline landfill leachates in a Facultative Lagoon Wastewater Treatment Plant (FLWTP). The FLWTP is near a landfill and presents two characteristics: a wastewater influent with low organic matter, and high lagoon salinity due to the soil characteristics. These characteristics made the FLWTP a viable candidate to evaluate the feasibility of adding landfill leachates to the wastewater influent. Different mixtures of leachate with raw wastewater using volumetric ratios of 4%, 6%, and 10% (v/v) were evaluated in facultative lagoon reactors (FLRs). A 10% concentration of leachates in raw wastewater increased BOD5 and COD in the influent from 45 to 110 mg L(-1) and from 219 to 711 mg L(-1), respectively. It was found that the increase in salinity given by the raw wastewater and leachate mixture did not inhibit algae diversity. The types of algae present were Microcystis sp., Merismopedia sp., Euglena sp., Scenedesmus sp., Chlorella, Diatomea and Anacystis sp. However, decreased algae densities were observed, as measured by the decrease in chlorophyll concentration. The results showed that a 100% leachate concentration combined with wastewater did not upset biological treatment in the FLRs. Mean removal efficiencies for BOD5 and COD were 75% and 35%, respectively, giving a final BOD5 lower than 25 mg L(-1). There was also a significant decrease in the leachate heavy metal content when diluted with raw wastewater as result of natural precipitation.

  8. On the circulation in the Puerto Morelos fringing reef lagoon

    NASA Astrophysics Data System (ADS)

    Coronado, C.; Candela, J.; Iglesias-Prieto, R.; Sheinbaum, J.; López, M.; Ocampo-Torres, F. J.

    2007-03-01

    For a period of 22 months beginning in September 2003, an array of four current profilers were deployed on the Puerto Morelos fringing reef lagoon, a microtidal Caribbean environment characterised by the influence of the Yucatan Current (YC) and a Trade Wind regime. The dataset includes water currents, bottom pressure, and surface waves complemented with coastal meteorological data and surface currents from an acoustic Doppler current profiler moored 12 km offshore. Normal circulation conditions consisted of a surface wave-induced flow entering the lagoon over a shallow reef flat and strong flows exiting through northern and southern channels. This wave induced flow was modulated by a low-frequency sea level change related to a geostrophic response to the YC variability offshore, with tidal and direct wind forcing playing additional minor roles. Under extended summer low-wave height conditions, together with a decrease in sea level from the intensification of the offshore current, the exchange of the lagoon with the adjacent ocean was drastically reduced. Under normal wave conditions ( H S = 0.8 ± 0.4 m, mean ± SD), water residence time was on average 3 h, whereas during Hurricane Ivan’s extreme swell ( H S = 6 m) it decreased to 0.35 h.

  9. The ecology of Mugu Lagoon, California: An estuarine profile

    SciTech Connect

    Onuf, C.P.

    1987-06-01

    Mugu Lagoon is significant as one of the least disturbed and best protected estuaries in southern California; thus this small estuarine system can serve as a baseline model for the region. This report summarizes and synthesizes scientific data on the ecological structure and functioning of the estuary, including discussions of climate, hydrology, geology, physiography, biotic assemblages, and ecological processes and interactions. The estuary exhibits extreme variability in freshwater inputs, being at times totally marine and at other times flushed by stormwater runoff from the watershed. Major storms in 1978 and 1980 resulted in sedimentation that drastically altered benthic communities and resulted in changes in the distribution of submerged aquatic vegetation and benthos, and fish and shorebird use of these food resources. Mugu Lagoon is part of a naval base and therefore not subject to the development pressures facing many other southern California estuaries. Storm-produced sedimentation remains a management concern, as well as closure of the mouth of the lagoon due to littoral drift of sand along the barrier spit.

  10. Beyond Survival

    ERIC Educational Resources Information Center

    Steffenson, Dave

    1975-01-01

    The author argues that environmentalists need to realize that the present ecological crisis is essentially a value crisis, not merely a fight for survival alone. He envisions a complete value change for the human population and advocates the incorporation of value strategies into all environmental education programs immediately. (MA)

  11. Drying kinetics and stabilization of sewage sludge in lagoon in hot climate.

    PubMed

    Idris, A; Yen, O B; Hamid, M H A; Baki, A M

    2002-01-01

    A sludge lagoon has been adopted as a simple and cost effective method for dewatering of sludge. The processes occurring in a sludge lagoon include thickening, dewatering, storage and stabilization; all happening simultaneously. The objective of this study is to determine the dewatering and drying rates at pilot-scale which occur in a lagoon having different design configurations. Two types of sludge lagoons with different initial sludge depth (0.75 m and 0.375 m) were investigated to measure the drying behavior and drying efficiency. The first design is a sludge lagoon with a clay bottom where the dewatering mechanisms are decanting supernatant and evaporation. The second design is a sludge lagoon installed with a sand and underdrains system, where the dewatering mechanisms are filtration or draining and evaporation. Sludge drying kinetic models with high fitness were plotted to describe the sludge drying behavior. Drying of sludge in a sludge lagoon with a clay bottom can best be described by an exponential function. Whereas, drying of sludge in a sludge lagoon with sand and underdrains system followed a logarithmic function. A lagoon designed with sand and underdrains system and having shallower sludge depth was the most efficient. The reduction in volatile solids was lower than 4% during the study period. The drying process proceeded with an increase in dryness and decline in pH value. PMID:12448479

  12. An integrated Pan-European perspective on coastal Lagoons management through a mosaic-DPSIR approach

    PubMed Central

    Dolbeth, Marina; Stålnacke, Per; Alves, Fátima L.; Sousa, Lisa P.; Gooch, Geoffrey D.; Khokhlov, Valeriy; Tuchkovenko, Yurii; Lloret, Javier; Bielecka, Małgorzata; Różyński, Grzegorz; Soares, João A.; Baggett, Susan; Margonski, Piotr; Chubarenko, Boris V.; Lillebø, Ana I.

    2016-01-01

    A decision support framework for the management of lagoon ecosystems was tested using four European Lagoons: Ria de Aveiro (Portugal), Mar Menor (Spain), Tyligulskyi Liman (Ukraine) and Vistula Lagoon (Poland/Russia). Our aim was to formulate integrated management recommendations for European lagoons. To achieve this we followed a DPSIR (Drivers-Pressures-State Change-Impacts-Responses) approach, with focus on integrating aspects of human wellbeing, welfare and ecosystem sustainability. The most important drivers in each lagoon were identified, based on information gathered from the lagoons’ stakeholders, complemented by scientific knowledge on each lagoon as seen from a land-sea perspective. The DPSIR cycles for each driver were combined into a mosaic-DPSIR conceptual model to examine the interdependency between the multiple and interacting uses of the lagoon. This framework emphasizes the common links, but also the specificities of responses to drivers and the ecosystem services provided. The information collected was used to formulate recommendations for the sustainable management of lagoons within a Pan-European context. Several common management recommendations were proposed, but specificities were also identified. The study synthesizes the present conditions for the management of lagoons, thus analysing and examining the activities that might be developed in different scenarios, scenarios which facilitate ecosystem protection without compromising future generations. PMID:26776151

  13. Composition and abundance of zooplankton community of an impacted estuarine lagoon in Northeast Brazil.

    PubMed

    Almeida, L R; Costa, I S; Eskinazi-Sant'anna, E M

    2012-02-01

    Guaraíras Lagoon is a shallow coastal lagoon subject to intense human impacts, including shrimp aquaculture, urban expansion and agricultural activities, and is therefore vulnerable to eutrophication. With the aim of detecting the effects of human-mediated disturbance and environmental change in the lagoon, a spatial-temporal study was conducted in order to assess the actual ecological status of the lagoon and the species composition and density of the mesozooplankton, highlighting copepod assemblages. Algal biomass (chlorophyll-a) and total phosphorus concentration indicated that the lagoon is a meso-eutrophic coastal system in the inner part, and is oligotrophic in the areas influenced by the marine waters. High salinities were recorded in the lagoon, characterizing the lagoon as a coastal-marine ecosystem, rather than true estuarine. Mesozooplankton abundance fluctuated widely and showed marked spatial heterogeneity. The copepod assemblage was characterized by a coastal/estuarine group dominated by Oithona spp., Acartia lilljeborgi and Parvocalanus crassirostris in the inner areas of the lagoon, and a marine group characterized by the copepods Paracalanus quasimodo, Calanopia americana, Corycaeus (C.) speciosus and Monstrilloida in the area of marine influence. Thus, the spatial variability in the distribution of mesozooplankton species can be ascribed to the presence of a horizontal gradient of salinity and trophic conditions. Overall, the results showed that spatial variation in the water physicochemical characteristics of Guarairas Lagoon have significant effects on the structure and repartition of the mesozooplankton assemblages, which may potentially affect the functioning and biodiversity of this coastal ecosystem.

  14. Drying kinetics and stabilization of sewage sludge in lagoon in hot climate.

    PubMed

    Idris, A; Yen, O B; Hamid, M H A; Baki, A M

    2002-01-01

    A sludge lagoon has been adopted as a simple and cost effective method for dewatering of sludge. The processes occurring in a sludge lagoon include thickening, dewatering, storage and stabilization; all happening simultaneously. The objective of this study is to determine the dewatering and drying rates at pilot-scale which occur in a lagoon having different design configurations. Two types of sludge lagoons with different initial sludge depth (0.75 m and 0.375 m) were investigated to measure the drying behavior and drying efficiency. The first design is a sludge lagoon with a clay bottom where the dewatering mechanisms are decanting supernatant and evaporation. The second design is a sludge lagoon installed with a sand and underdrains system, where the dewatering mechanisms are filtration or draining and evaporation. Sludge drying kinetic models with high fitness were plotted to describe the sludge drying behavior. Drying of sludge in a sludge lagoon with a clay bottom can best be described by an exponential function. Whereas, drying of sludge in a sludge lagoon with sand and underdrains system followed a logarithmic function. A lagoon designed with sand and underdrains system and having shallower sludge depth was the most efficient. The reduction in volatile solids was lower than 4% during the study period. The drying process proceeded with an increase in dryness and decline in pH value.

  15. Spatiotemporal variation of bacterial community composition and possible controlling factors in tropical shallow lagoons.

    PubMed

    Laque, Thaís; Farjalla, Vinicius F; Rosado, Alexandre S; Esteves, Francisco A

    2010-05-01

    Bacterial community composition (BCC) has been extensively related to specific environmental conditions. Tropical coastal lagoons present great temporal and spatial variation in their limnological conditions, which, in turn, should influence the BCC. Here, we sought for the limnological factors that influence, in space and time, the BCC in tropical coastal lagoons (Rio de Janeiro State, Brazil). The Visgueiro lagoon was sampled monthly for 1 year and eight lagoons were sampled once for temporal and spatial analysis, respectively. BCC was evaluated by bacteria-specific PCR-DGGE methods. Great variations were observed in limnological conditions and BCC on both temporal and spatial scales. Changes in the BCC of Visgueiro lagoon throughout the year were best related to salinity and concentrations of NO (3) (-) , dissolved phosphorus and chlorophyll-a, while changes in BCC between lagoons were best related to salinity and dissolved phosphorus concentration. Salinity has a direct impact on the integrity of the bacterial cell, and it was previously observed that phosphorus is the main limiting nutrient to bacterial growth in these lagoons. Therefore, we conclude that great variations in limnological conditions of coastal lagoons throughout time and space resulted in different BCCs and salinity and nutrient concentration, particularly dissolved phosphorus, are the main limnological factors influencing BCC in these tropical coastal lagoons.

  16. Assessing the impact of animal waste lagoon seepage on the geochemistry of an underlying shallow aquifer.

    PubMed

    McNab, Walt W; Singleton, Michael J; Moran, Jean E; Esser, Brad K

    2007-02-01

    Evidence of seepage from animal waste holding lagoons at a dairy facility in the San Joaquin Valley of California is assessed in the context of a process geochemical model that addresses reactions associated with the formation of the lagoon water as well as reactions occurring upon the mixture of lagoon water with underlying aquifer material. Comparison of model results with observed concentrations of NH4+, K+, PO4(3-), dissolved inorganic carbon, pH, Ca2+, Mg2+, SO4(2-), Cl-, and dissolved Ar in lagoon water samples and groundwater samples suggests three key geochemical processes: (i) off-gassing of significant quantities of CO2 and CH4 during mineralization of manure in the lagoon water, (ii) ion exchange reactions that remove K+ and NH4+ from seepage water as it migrates into the underlying anaerobic aquifer material, and (iii) mineral precipitation reactions involving phosphate and carbonate minerals in the lagoon water in response to an increase in pH as well as in the underlying aquifer from elevated Ca2+ and Mg2+ levels generated by ion exchange. Substantial off-gassing from the lagoons is further indicated by dissolved argon concentrations in lagoon water samples that are below atmospheric equilibrium. As such, Ar may serve as a unique tracer for lagoon water seepage since under-saturated Ar concentrations in groundwater are unlikely to be influenced by any processes other than mechanical mixing.

  17. The effect of floods on sediment contamination in a microtidal coastal lagoon: the lagoon of Lesina, Italy.

    PubMed

    D'Adamo, Raffaele; Specchiulli, Antonietta; Cassin, Daniele; Botter, Margherita; Zonta, Roberto; Fabbrocini, Adele

    2014-10-01

    The effects on the microtidal lagoon of Lesina of runoff and the discharge of water and material from agricultural activities were investigated combining chemical analyses of pollutants [11 metals and 16 priority polycyclic aromatic compounds (PAHs)], determination of organic matter and grain size, and performance of innovative ecotoxicological tests. For metals, enrichment factors >3 for arsenic, nickel, and copper (Cu) were observed in the eastern zone of the lagoon, which is affected by nearby urban activities with discharge of water and domestic waste and by agricultural input with waters rich in fertilizers. Cu was correlated with no other metal, and its high concentrations (≤77 µg g(-1)) may result from the use of Cu-based fungicides in vineyards. Total PAHs (2,230 ± 3,150 ng g(-1)) displayed a wide range of concentrations with hot spots near freshwater inputs from the part of the catchment area exploited for wheat crops. Pyrolitic contamination also emerged, with higher-mass PAH congeners, such as asphalt, bitumen or coal, usually present in higher fractions as the dominant components. Ecotoxicological evaluations recorded moderate to high toxicity levels; the innovative MOT test bioassay showed good discriminatory ability because it identified a lagoon area whose inputs mainly depend on agricultural activities and which is impacted by metals rather than PAHs. Floods during periods of heavy rain and the discharge of water and material from agricultural activities may impact vulnerable systems, such as the lagoon of Lesina, where the presence of hot spots with remarkably high pollution values was observed.

  18. Groundwater and porewater as a major source of alkalinity to a fringing coral reef lagoon (Muri Lagoon, Cook Islands)

    NASA Astrophysics Data System (ADS)

    Cyronak, T.; Santos, I. R.; Erler, D. V.; Eyre, B. D.

    2012-11-01

    To better predict how ocean acidification will affect coral reefs, it is important to understand how biogeochemical cycles on reefs alter carbonate chemistry over various temporal and spatial scales. This study quantifies the contribution of fresh groundwater discharge (as traced by radon) and shallow porewater exchange (as quantified from advective chamber incubations) to total alkalinity (TA) dynamics on a fringing coral reef lagoon along the southern Pacific island of Rarotonga over a tidal and diel cycle. Benthic alkalinity fluxes were affected by the advective circulation of water through permeable sediments, with net daily flux rates of carbonate alkalinity ranging from -1.55 to 7.76 mmol m-2 d-1, depending on the advection rate. Submarine groundwater discharge (SGD) was a source of TA to the lagoon, with the highest flux rates measured at low tide, and an average daily TA flux of 1080 mmol m-2 d-1. Both sources of TA were important on a reef wide basis, although SGD acted solely as a delivery mechanism of TA to the lagoon, while porewater advection was either a sink or source of TA dependant on the time of day. On a daily basis, groundwater can contribute approximately 70% to 80% of the TA taken up by corals within the lagoon. This study describes overlooked sources of TA to coral reef ecosystems that can potentially alter water-column carbonate chemistry. We suggest that porewater and groundwater fluxes of TA should be taken into account in ocean acidification models in order to properly address changing carbonate chemistry within coral reef ecosystems.

  19. Depositional history and fault-related studies, Bolinas Lagoon, California

    USGS Publications Warehouse

    Berquist, Joel R.

    1978-01-01

    Studies of core sediments and seismic reflection profiles elucidate the structure and depositional history of Bolinas Lagoon, Calif., which covers 4.4 km 2 and lies in the San Andreas fault zone at the southeast corner of the Point Reyes Peninsula 20 km northwest of San Francisco. The 1906 trace of the San Andreas fault crosses the west side of the lagoon and was determined from (1) tectonically caused salt-marsh destruction indicated by comparison of 1854 and 1929 U.S. Coast and Geodetic Survey (U.S.C. & G.S.) topographic surveys, (2) formation of a tidal channel along the border of destroyed salt marshes, and (3) azimuths of the trend of the fault measured in 1907. Subsidence in the lagoon of 30 cm occurred east of the San Andreas fault in 1906. Near the east shore, seismic-reflection profiling indicates the existence of a graben fault that may connect to a graben fault on the Golden Gate Platform. Comparison of radiocarbon dates on shells and plant debris from boreholes drilled on Stinson Beach spit with a relative sea-level curve constructed for southern San Francisco Bay indicates 5.8 to more than 17.9 m of tectonic subsidence of sediments now located 33 m below mean sea level. Cored sediments indicate a marine transgression dated at 7770?65 yrs B.P. overlying freshwater organic-rich lake deposits. Fossil pollen including 2 to 8 percent Picea (spruce) indicate a late Pleistocene (?)-Early Holocene climate, cooler, wetter, and foggier than at present. Above the transgression are discontinuous and interfingering sequences of transgressive-regressive marine, estuarine, and barrier sediments that reflect rapid lateral and vertical shifts of successive depositional environments. Fossil megafauna indicate (1) accumulation in a protected, shallow-water estuary or bay, and (2) that the lagoon was probably continuously shallow and never a deep-water embayment. Analysis of grain-size parameters, pollen frequencies, and organic remains from a core near the north end of

  20. Groundwater and porewater as major sources of alkalinity to a fringing coral reef lagoon (Muri Lagoon, Cook Islands)

    NASA Astrophysics Data System (ADS)

    Cyronak, T.; Santos, I. R.; Erler, D. V.; Eyre, B. D.

    2013-04-01

    To better predict how ocean acidification will affect coral reefs, it is important to understand how biogeochemical cycles on reefs alter carbonate chemistry over various temporal and spatial scales. This study quantifies the contribution of shallow porewater exchange (as quantified from advective chamber incubations) and fresh groundwater discharge (as traced by 222Rn) to total alkalinity (TA) dynamics on a fringing coral reef lagoon along the southern Pacific island of Rarotonga over a tidal and diel cycle. Benthic alkalinity fluxes were affected by the advective circulation of water through permeable sediments, with net daily flux rates of carbonate alkalinity ranging from -1.55 to 7.76 mmol m-2 d-1, depending on the advection rate. Submarine groundwater discharge (SGD) was a source of TA to the lagoon, with the highest flux rates measured at low tide, and an average daily TA flux of 1080 mmol m-2 d-1 at the sampling site. Both sources of TA were important on a reef-wide basis, although SGD acted solely as a delivery mechanism of TA to the lagoon, while porewater advection was either a sink or source of TA dependent on the time of day. This study describes overlooked sources of TA to coral reef ecosystems that can potentially alter water column carbonate chemistry. We suggest that porewater and groundwater fluxes of TA should be taken into account in ocean acidification models in order to properly address changing carbonate chemistry within coral reef ecosystems.

  1. Mangroves enhance the biomass of coral reef fish communities in the Caribbean.

    PubMed

    Mumby, Peter J; Edwards, Alasdair J; Arias-González, J Ernesto; Lindeman, Kenyon C; Blackwell, Paul G; Gall, Angela; Gorczynska, Malgosia I; Harborne, Alastair R; Pescod, Claire L; Renken, Henk; Wabnitz, Colette C C; Llewellyn, Ghislane

    2004-02-01

    Mangrove forests are one of the world's most threatened tropical ecosystems with global loss exceeding 35% (ref. 1). Juvenile coral reef fish often inhabit mangroves, but the importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fish populations may be regulated by other limiting factors such as larval supply or fishing. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves. The largest herbivorous fish in the Atlantic, Scarus guacamaia, has a functional dependency on mangroves and has suffered local extinction after mangrove removal. Current rates of mangrove deforestation are likely to have severe deleterious consequences for the ecosystem function, fisheries productivity and resilience of reefs. Conservation efforts should protect connected corridors of mangroves, seagrass beds and coral reefs. PMID:14765193

  2. Comparing Aedes vigilax Eggshell Densities in Saltmarsh and Mangrove Systems with Implications for Management.

    PubMed

    Dale, Pat; Knight, Jon; Griffin, Lachlan

    2014-01-01

    Aedes vigilax (Skuse), a nuisance and disease vector, is prolific in intertidal wetlands in Australia. Aedine mosquitoes oviposit directly onto substrate. The eggshells are relatively stable spatially and temporally, providing an estimate of mosquito larval production. The aims of the research were to compare, at a general level, oviposition in mangroves and saltmarshes, and to compare oviposition between different habitats within mangroves and saltmarshes. The results indicated that there were no significant differences between production in mangrove and saltmarsh overall. However, within each system there were significant differences between habitat classes, with mangrove hummocks being the most productive. All classes, except for fringing mangrove forests, produced sufficient densities of eggshells (>0.05/cc) to warrant concern. While mosquito production in mangroves is known, the significantly higher production rates in the mangrove hummock habitats had not been demonstrated. This warrants improved management strategies that both specifically target these parts of mangrove systems and, secondly, addresses the longer-term potential for mangrove hummock habitats developing in the future; such as, in response to sea level rise and mangrove encroachment into saltmarsh. A strategy to increase tidal flushing within the systems would improve water quality and mitigate adverse impacts while providing a source reduction outcome.

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

    USGS Publications Warehouse

    Ren, H.; Jian, S.; Lu, H.; Zhang, Q.; Shen, W.; Han, W.; Yin, Z.; Guo, Q.

    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 forest. We found that severely degraded mangrove stands could not regenerate naturally without human intervention due to severely altered local environments, whereas some native species had been recruited into the 4-10 year S. apetala plantations. In the first 10 years, the exotic species S. apetala grew better than native species such as Rhizophora stylosa Griff and Kandelia candel (Linn.) Druce. The mangrove plantation gradually affected soil physical and chemical properties during its recovery. The exotic S. apetala was more competitive than native species and its plantation was able to restore soil organic matter in about 14 years. Thus, S. apetala can be considered as a pioneer species to improve degraded habitats to facilitate recolonisation by native mangrove species. However, removal to control proliferation may be needed at late stages to facilitate growth of native species. To ensure sustainability of mangroves in South China, the existing mangrove wetlands must be managed as an ecosystem, with long-term scientific monitoring program in place. ?? 2007 The Ecological Society of Japan.

  4. Chemical ecology of red mangroves, Rhizophora mangle, in the Hawaiian Islands

    USGS Publications Warehouse

    Fry, Brian; Cormier, Nicole

    2011-01-01

    The coastal red mangrove, Rhizophora mangle L., was introduced to the Hawaiian Islands from Florida 100 yr ago and has spread to cover many shallow intertidal shorelines that once were unvegetated mudflats. We used a field survey approach to test whether mangroves at the land-ocean interface could indicate watershed inputs, especially whether measurements of leaf chemistry could identify coasts with high nutrient inputs and high mangrove productivities. During 2001-2002, we sampled mangroves on dry leeward coasts of southern Moloka'i and O'ahu for 14 leaf variables including stable carbon and nitrogen isotopes (delta13C, delta15N), macronutrients (C, N, P), trace elements (B, Mn, Fe, Cu, Zn), and cations (Na, Mg, K, Ca). A new modeling approach using leaf Na, N, P, and delta13C indicated two times higher productivity for mangroves in urban versus rural settings, with rural mangroves more limited by low N and P nutrients and high-nutrient urban mangroves more limited by freshwater inputs and salt stress. Leaf chemistry also helped identify other aspects of mangrove dynamics: especially leaf delta15N values helped identify groundwater N inputs, and a combination of strongly correlated variables (C, N, P, B, Cu, Mg, K, Ca) tracked the mangrove growth response to nutrient loading. Overall, the chemical marker approach is an efficient way to survey watershed forcing of mangrove forest dynamics.

  5. Mangroves enhance the biomass of coral reef fish communities in the Caribbean

    NASA Astrophysics Data System (ADS)

    Mumby, Peter J.; Edwards, Alasdair J.; Ernesto Arias-González, J.; Lindeman, Kenyon C.; Blackwell, Paul G.; Gall, Angela; Gorczynska, Malgosia I.; Harborne, Alastair R.; Pescod, Claire L.; Renken, Henk; C. C. Wabnitz, Colette; Llewellyn, Ghislane

    2004-02-01

    Mangrove forests are one of the world's most threatened tropical ecosystems with global loss exceeding 35% (ref. 1). Juvenile coral reef fish often inhabit mangroves, but the importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fish populations may be regulated by other limiting factors such as larval supply or fishing. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves. The largest herbivorous fish in the Atlantic, Scarus guacamaia, has a functional dependency on mangroves and has suffered local extinction after mangrove removal. Current rates of mangrove deforestation are likely to have severe deleterious consequences for the ecosystem function, fisheries productivity and resilience of reefs. Conservation efforts should protect connected corridors of mangroves, seagrass beds and coral reefs.

  6. Mangroves enhance the biomass of coral reef fish communities in the Caribbean.

    PubMed

    Mumby, Peter J; Edwards, Alasdair J; Arias-González, J Ernesto; Lindeman, Kenyon C; Blackwell, Paul G; Gall, Angela; Gorczynska, Malgosia I; Harborne, Alastair R; Pescod, Claire L; Renken, Henk; Wabnitz, Colette C C; Llewellyn, Ghislane

    2004-02-01

    Mangrove forests are one of the world's most threatened tropical ecosystems with global loss exceeding 35% (ref. 1). Juvenile coral reef fish often inhabit mangroves, but the importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fish populations may be regulated by other limiting factors such as larval supply or fishing. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves. The largest herbivorous fish in the Atlantic, Scarus guacamaia, has a functional dependency on mangroves and has suffered local extinction after mangrove removal. Current rates of mangrove deforestation are likely to have severe deleterious consequences for the ecosystem function, fisheries productivity and resilience of reefs. Conservation efforts should protect connected corridors of mangroves, seagrass beds and coral reefs.

  7. Recruitment and growth of two small-bodied resident fish species (Gobiidae and Atherinidae) in oligohaline, seasonally open lagoons.

    PubMed

    Close, P G; Davies, P M; Trayler, K

    2010-04-01

    Spatio-temporal recruitment patterns, growth and survival of the Swan River goby Pseudogobius olorum and western hardyhead Leptatherina wallacei are described from two small, coastal lagoons on the south coast of Western Australia. In these lagoons, estuarine salinity dynamics were relatively stable over much of the autumn-spring period when freshwater inputs from rivers were reduced and there was no oceanic connection. Preflexion and flexion stages of both fish species contributed strongly to population size structure in downstream reaches, whereas upstream reaches were dominated by postflexion larvae and juvenile stages. Spawning of both species was protracted and largely asynchronous, although the episodic presence of stronger preflexion and flexion cohorts suggested some synchronized spawning had occurred. Comparison with estuarine conditions over this period provided evidence that synchronized spawning may be related to temperature and salinity variations from a combination of freshwater inputs and periods of marine exchange. Uninterrupted growth and the progression of cohorts through to juvenile stages were consistent with the generally stable estuarine conditions. Larval and juvenile stages of both species were also tolerant of abrupt changes in salinity and temperature, which occurred due to a non-seasonal oceanic connection. These findings were consistent with the euryhaline nature of adults of both species.

  8. Mapping and Change Analysis in Mangrove Forest by Using Landsat Imagery

    NASA Astrophysics Data System (ADS)

    Dan, T. T.; Chen, C. F.; Chiang, S. H.; Ogawa, S.

    2016-06-01

    Mangrove is located in the tropical and subtropical regions and brings good services for native people. Mangrove in the world has been lost with a rapid rate. Therefore, monitoring a spatiotemporal distribution of mangrove is thus critical for natural resource management. This research objectives were: (i) to map the current extent of mangrove in the West and Central Africa and in the Sundarbans delta, and (ii) to identify change of mangrove using Landsat data. The data were processed through four main steps: (1) data pre-processing including atmospheric correction and image normalization, (2) image classification using supervised classification approach, (3) accuracy assessment for the classification results, and (4) change detection analysis. Validation was made by comparing the classification results with the ground reference data, which yielded satisfactory agreement with overall accuracy 84.1% and Kappa coefficient of 0.74 in the West and Central Africa and 83.0% and 0.73 in the Sundarbans, respectively. The result shows that mangrove areas have changed significantly. In the West and Central Africa, mangrove loss from 1988 to 2014 was approximately 16.9%, and only 2.5% was recovered or newly planted at the same time, while the overall change of mangrove in the Sundarbans increased approximately by 900 km2 of total mangrove area. Mangrove declined due to deforestation, natural catastrophes deforestation and mangrove rehabilitation programs. The overall efforts in this study demonstrated the effectiveness of the proposed method used for investigating spatiotemporal changes of mangrove and the results could provide planners with invaluable quantitative information for sustainable management of ma