Studies of Louisiana's Deltas and Wetlands using SAR

Science.gov (United States)

Jones, C. E.

2017-12-01

Sustainable coastal environments exist in delicate balance between subsidence, erosion, and sea level rise on one hand and accretion of sediment and retention of decomposing organic matter on the other. In this talk we present results from a series of studies using an airborne L-band SAR (UAVSAR) to measure changing conditions in the Mississippi River Delta and coastal wetlands of Louisiana. Change within the Mississippi River delta (MRD), which is a highly engineered environment, is contrasted to those in the Wax Lake Delta, a small, naturally evolving delta located to the west of the current-day lobe of the MRD. The UAVSAR studies provide evidence that in the MRD subsidence and erosion related to human activities are increasing risk of flooding, submergence, and land loss. These are not seen in the Wax Lake Delta, where new land is forming. We evaluate geomorphic and hydrologic changes In the Wax Lake Delta and wetlands hydrologically connected to the Wax Lake Outlet canal that are apparent on the timescales of the UAVSAR data set, which consists of both near-yearly acquisitions (2009-2016) and several series of repeat acquisitions in 2015 and 2016 capturing conditions across a tidal cycle. Using the yearly data, we observe the evolution of subaqueous channels and crevasses in the delta and changes in distributary channels within the wetlands. We use water level change derived from InSAR applied to the rapid repeat data acquired during different stages of a tidal cycle to study the natural pattern of water flux within the delta and the coastal wetlands. The studies, results, and plans for future work will be presented. This work was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under contracts with the California Dept. of Water Resources and with the National Aeronautics and Space Administration.

Innovative approach for restoring coastal wetlands using treated drill cuttings

International Nuclear Information System (INIS)

Veil, J. A.; Hocking, E. K.

1999-01-01

The leading environmental problem facing coastal Louisiana regions is the loss of wetlands. Oil and gas exploration and production activities have contributed to wetland damage through erosion at numerous sites where canals have been cut through the marsh to access drilling sites. An independent oil and gas producer, working with Southeastern Louisiana University and two oil field service companies, developed a process to stabilize drill cuttings so that they could be used as a substrate to grow wetlands vegetation. The U.S. Department of Energy (DOE) funded a project under which the process would be validated through laboratory studies and field demonstrations. The laboratory studies demonstrated that treated drill cuttings support the growth of wetlands vegetation. However, neither the Army Corps of Engineers (COE) nor the U.S. Environmental Protection Agency (EPA) would grant regulatory approval for afield trial of the process. Argonne National Laboratory was asked to join the project team to try to find alternative mechanisms for gaining regulatory approval. Argonne worked with EPA's Office of Reinvention and learned that EPA's Project XL would be the only regulatory program under which the proposed field trial could be done. One of the main criteria for an acceptable Project XL proposal is to have a formal project sponsor assume the responsibility and liability for the project. Because the proposed project involved access to private land areas, the team felt that an oil and gas company with coastal Louisiana land holdings would need to serve as sponsor. Despite extensive communication with oil and gas companies and industry associations, the project team was unable to find any organization willing to serve as sponsor. In September 1999, the Project XL proposal was withdrawn and the project was canceled

Fate of petroleum hydrocarbons and toxic organics in Louisiana coastal environments

International Nuclear Information System (INIS)

DeLaune, R.D.; Gambrell, R.P.; Pardue, J.H.; Patrick, W.H. Jr.

1991-01-01

Numerous potentially toxic compounds are entering Louisiana's inshore and nearshore coastal environments. To a large degree there is insufficient information for predicting the fate and effect of these materials in aquatic environments. Studies documenting the impact of petroleum hydrocarbons entering Louisiana coastal wetlands are summarized. Also included are research findings on factors affecting the persistence of petroleum hydrocarbons and other toxic organics (pentachlorophenol (PCP), 2,4-dichlorophenoxyacetic acid (2,4-D), creosote, etc.) in sediment-water systems. Sediment pH and redox conditions have been found to play an important role in the microbial degradation of toxic organics. Most of the hydrocarbons investigated degrade more rapidly under high redox (aerobic) conditions although there are exceptions (e.g., 1,1,1-trichloro-2,2-bis(4-chlorophenyl)(DDT) and polychlorobiphenyls (PCBs)). Some of these compounds, due to their slow degradation in anaerobic sediment, may persist in the system for decades

Influence of the Houma Navigation Canal on Salinity Patterns and Landscape Configuration in Coastal Louisiana

Science.gov (United States)

Steyer, Gregory D.; Sasser, Charles; Evers, Elaine; Swenson, Erick; Suir, Glenn; Sapkota, Sijan

2008-01-01

Coastal Louisiana is a dynamic and ever changing landscape. From 1956 to 2004, over 297,000 ha of Louisiana's coastal wetlands were lost because of the effects of natural and human-induced activities. Studies show that, in 2005, Hurricanes Katrina and Rita transformed over 56,200 ha of wetlands to open water in various parts of coastal Louisiana. Besides the catastrophic hurricanes, factors such as subsidence, sea-level rise, freshwater and sediment deprivation, saltwater intrusion, the dredging of oil and gas canals, navigation canals, shoreline erosion, and herbivory are all contributors to wetland loss in Louisiana. Various scientific literatures have well described the direct impacts associated with an immediate physical conversion of habitat in coastal Louisiana; however, the indirect impacts that are subtle and operate over longer time horizons (such as salinity intrusion) have been difficult to discern. In this report, long-term influences on salinity patterns and landscape configuration are evaluated for pre- and postconstruction periods of the Houma Navigation Canal (HNC), which is located in the coastal region of southeastern Louisiana. Analysis of daily and hourly salinity data from long-term data collection stations within the areas surrounding the HNC indicated that there were no obvious patterns in increasing salinity levels following the completion of the canal, except for the immediate increase in salinity spikes that occurred toward the completion of its construction in 1961. Increases in salinity spikes were also observed during a severe drought in 1999-2000. Data from Bayou Grand Caillou at Dulac, however, show a longer term trend of increasing salinity levels, which is similar to the pattern observed at the Houma Water Treatment Plant. A potential explanation for these patterns is based on the dredging history of the HNC, where dates of maintenance dredging correspond fairly closely to the salinity peaks in Bayou Grand Caillou and the canal. It

Forecasting landscape effects of Mississippi River diversions on elevation and accretion in Louisiana deltaic wetlands under future environmental uncertainty scenarios

Science.gov (United States)

Wang, Hongqing; Steyer, Gregory D.; Couvillion, Brady R.; John M. Rybczyk,; Beck, Holly J.; William J. Sleavin,; Ehab A. Meselhe,; Mead A. Allison,; Ronald G. Boustany,; Craig J. Fischenich,; Victor H. Rivera-Monroy,

2014-01-01

Large sediment diversions are proposed and expected to build new wetlands to alleviate the extensive wetland loss (5,000 km2) affecting coastal Louisiana during the last 78 years. Current assessment and prediction of the impacts of sediment diversions have focused on the capture and dispersal of both water and sediment on the adjacent river side and the immediate outfall marsh area. However, little is known about the effects of sediment diversions on existing wetland surface elevation and vertical accretion dynamics in the receiving basin at the landscape scale. In this study, we used a spatial wetland surface elevation model developed in support of Louisiana's 2012 Coastal Master Plan to examine such landscape-scale effects of sediment diversions. Multiple sediment diversion projects were incorporated in the model to simulate surface elevation and vertical accretion for the next 50 years (2010-2060) under two environmental (moderate and less optimistic) scenarios. Specifically, we examined landscape-scale surface elevation and vertical accretion trends under diversions with different geographical locations, diverted discharge rates, and geomorphic characteristics of the receiving basin. Model results indicate that small diversions ( 1,500 m3 s-1) are required to achieve landscape-level benefits to promote surface elevation via vertical accretion to keep pace with rising sea level.

A Geostatistical Toolset for Reconstructing Louisiana's Coastal Stratigraphy using Subsurface Boring and Cone Penetrometer Test Data

Science.gov (United States)

Li, A.; Tsai, F. T. C.; Jafari, N.; Chen, Q. J.; Bentley, S. J.

2017-12-01

A vast area of river deltaic wetlands stretches across southern Louisiana coast. The wetlands are suffering from a high rate of land loss, which increasingly threats coastal community and energy infrastructure. A regional stratigraphic framework of the delta plain is now imperative to answer scientific questions (such as how the delta plain grows and decays?) and to provide information to coastal protection and restoration projects (such as marsh creation and construction of levees and floodwalls). Through years, subsurface investigations in Louisiana have been conducted by state and federal agencies (Louisiana Department of Natural Resources, United States Geological Survey, United States Army Corps of Engineers, etc.), research institutes (Louisiana Geological Survey, LSU Coastal Studies Institute, etc.), engineering firms, and oil-gas companies. This has resulted in the availability of various types of data, including geological, geotechnical, and geophysical data. However, it is challenging to integrate different types of data and construct three-dimensional stratigraphy models in regional scale. In this study, a set of geostatistical methods were used to tackle this problem. An ordinary kriging method was used to regionalize continuous data, such as grain size, water content, liquid limit, plasticity index, and cone penetrometer tests (CPTs). Indicator kriging and multiple indicator kriging methods were used to regionalize categorized data, such as soil classification. A compositional kriging method was used to regionalize compositional data, such as soil composition (fractions of sand, silt and clay). Stratigraphy models were constructed for three cases in the coastal zone: (1) Inner Harbor Navigation Canal (IHNC) area: soil classification and soil behavior type (SBT) stratigraphies were constructed using ordinary kriging; (2) Middle Barataria Bay area: a soil classification stratigraphy was constructed using multiple indicator kriging; (3) Lower Barataria

Preventing land loss in coastal Louisiana: estimates of WTP and WTA.

Science.gov (United States)

Petrolia, Daniel R; Kim, Tae-Goun

2011-03-01

A dichotomous-choice contingent-valuation survey was conducted in the State of Louisiana (USA) to estimate compensating surplus (CS) and equivalent surplus (ES) welfare measures for the prevention of future coastal wetland losses in Louisiana. Valuations were elicited using both willingness to pay (WTP) and willingness to accept compensation (WTA) payment vehicles. Mean CS (WTP) estimates based on a probit model using a Box-Cox specification on income was $825 per household annually, and mean ES (WTA) was estimated at $4444 per household annually. Regression results indicate that the major factors influencing support for land-loss prevention were income (positive, WTP model only), perceived hurricane protection benefits (positive), environmental and recreation protection (positive), distrust of government (negative), age (positive, WTA model only), and race (positive for whites). Copyright © 2010 Elsevier Ltd. All rights reserved.

In-situ Geotechnical Characterization of Wetland Channel Cross Sections in Coastal Louisiana Using a Portable Free-fall Penetrometer

Science.gov (United States)

Bilici, C.; Stark, N.; Ghose Hajra, M.

2016-02-01

Broader comprehension of sediment dynamics in wetland channels is essential to protect and restore wetland areas in a sustainable manner. This study focused on a wetland channel located west of Lake Borgne in coastal Louisiana. In-situ tests were performed using a portable free fall penetrometer (PFFP), targeting the characterization of wetland channel sediment characteristics and dynamics. Data were collected at 102 locations along 3 cross-channel transects. Results indicated distinct variations in sediment properties across the channel. Sediments located centrally in the channel were soft and exhibited a similar sediment strength along the channel (0.75 - 3.5 kPa at 20 cm below channel bed surface; 4 - 10 kPa at 100 cm). The sediment strength near the channel banks increased up to 20 kPa at 20 cm below channel bed, while sediment samples did not indicate a significant variation in sediment type. Thus, surficial sediments located at the center of channel appeared less consolidated than at the channel banks. This likely resulted from erosion removing looser sediments due to differences in channel flow patterns or wake waves from boat activity. Furthermore, the thickness of a loose sediment top layer varied for the opposing banks of transects. This may be related to local changes in channel shape. Particularly in meandering parts of the channels, loose sediment layers were limited up to a thickness of 5 cm at the outer bank of individual meanders, while it reached a thickness of 15 cm at the inner bank. This matched the expectations of erosion at the outer banks and deposition on the inner banks. At some locations, asymmetric sediment layers on opposing banks of channel transects were likely related to local channel tributaries. These tributaries may act as a sediment sink or source affecting sedimentation in the investigated channel.

Gulf-Wide Information System, Environmental Sensitivity Index Scrub-Shrub and Wetlands, Geographic NAD83, LDWF (2001) [esi_scrub-shrub_wetland_LDWF_2001

Data.gov (United States)

Louisiana Geographic Information Center — This data set contains Environmental Sensitivity Index (ESI) scrub-shrub and wetlands data of coastal Louisiana. The ESI is a classification and ranking system,...

Hurricane impacts on coastal wetlands: a half-century record of storm-generated features from southern Louisiana

Science.gov (United States)

Morton, Robert A.; Barras, John A.

2011-01-01

Temporally and spatially repeated patterns of wetland erosion, deformation, and deposition are observed on remotely sensed images and in the field after hurricanes cross the coast of Louisiana. The diagnostic morphological wetland features are products of the coupling of high-velocity wind and storm-surge water and their interaction with the underlying, variably resistant, wetland vegetation and soils. Erosional signatures include construction of orthogonal-elongate ponds and amorphous ponds, pond expansion, plucked marsh, marsh denudation, and shoreline erosion. Post-storm gravity reflux of floodwater draining from the wetlands forms dendritic incisions around the pond margins and locally integrates drainage pathways forming braided channels. Depositional signatures include emplacement of broad zones of organic wrack on topographic highs and inorganic deposits of variable thicknesses and lateral extents in the form of shore-parallel sandy washover terraces and interior-marsh mud blankets. Deformational signatures primarily involve laterally compressed marsh and displaced marsh mats and balls. Prolonged water impoundment and marsh salinization also are common impacts associated with wetland flooding by extreme storms. Many of the wetland features become legacies that record prior storm impacts and locally influence subsequent storm-induced morphological changes. Wetland losses caused by hurricane impacts depend directly on impact duration, which is controlled by the diameter of hurricane-force winds, forward speed of the storm, and wetland distance over which the storm passes. Distinguishing between wetland losses caused by storm impacts and losses associated with long-term delta-plain processes is critical for accurate modeling and prediction of future conversion of land to open water.

Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region

International Nuclear Information System (INIS)

Hall, B.D.; Aiken, G.R.; Krabbenhoft, D.P.; Marvin-DiPasquale, M.; Swarzenski, C.M.

2008-01-01

It is widely recognized that wetlands, especially those rich in organic matter and receiving appreciable atmospheric mercury (Hg) inputs, are important sites of methylmercury (MeHg) production. Extensive wetlands in the southeastern United States have many ecosystem attributes ideal for promoting high MeHg production rates; however, relatively few mercury cycling studies have been conducted in these environments. We conducted a landscape scale study examining Hg cycling in coastal Louisiana (USA) including four field trips conducted between August 2003 and May 2005. Sites were chosen to represent different ecosystem types, including: a large shallow eutrophic estuarine lake (Lake Pontchartrain), three rivers draining into the lake, a cypress-tupelo dominated freshwater swamp, and six emergent marshes ranging from a freshwater marsh dominated by Panicum hemitomon to a Spartina alterniflora dominated salt marsh close to the Gulf of Mexico. We measured MeHg and total Hg (THg) concentrations, and ancillary chemical characteristics, in whole and filtered surface water, and filtered porewater. Overall, MeHg concentrations were greatest in surface water of freshwater wetlands and lowest in the profundal (non-vegetated) regions of the lake and river mainstems. Concentrations of THg and MeHg in filtered surface water were positively correlated with the highly reactive, aromatic (hydrophobic organic acid) fraction of dissolved organic carbon (DOC). These results suggest that DOC plays an important role in promoting the mobility, transport and bioavailability of inorganic Hg in these environments. Further, elevated porewater concentrations in marine and brackish wetlands suggest coastal wetlands along the Gulf Coast are key sites for MeHg production and may be a principal source of MeHg to foodwebs in the Gulf of Mexico. Examining the relationships among MeHg, THg, and DOC across these multiple landscape types is a first step in evaluating possible links between key zones for

Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region

Energy Technology Data Exchange (ETDEWEB)

Hall, B.D. [Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI 53706 (United States); Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2 (Canada)], E-mail: britt.hall@uregina.ca; Aiken, G.R. [United States Geological Survey, 3215 Marine Street, Boulder, CO 80303 (United States); Krabbenhoft, D.P. [United States Geological Survey, 8505 Research Way, Middleton, WI 53562 (United States); Marvin-DiPasquale, M. [United States Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 (United States); Swarzenski, C.M. [United States Geological Survey, Suite 120, 3535 S. Sherwood Forest Blvd., Baton Rouge, LA 70816 (United States)

2008-07-15

It is widely recognized that wetlands, especially those rich in organic matter and receiving appreciable atmospheric mercury (Hg) inputs, are important sites of methylmercury (MeHg) production. Extensive wetlands in the southeastern United States have many ecosystem attributes ideal for promoting high MeHg production rates; however, relatively few mercury cycling studies have been conducted in these environments. We conducted a landscape scale study examining Hg cycling in coastal Louisiana (USA) including four field trips conducted between August 2003 and May 2005. Sites were chosen to represent different ecosystem types, including: a large shallow eutrophic estuarine lake (Lake Pontchartrain), three rivers draining into the lake, a cypress-tupelo dominated freshwater swamp, and six emergent marshes ranging from a freshwater marsh dominated by Panicum hemitomon to a Spartina alterniflora dominated salt marsh close to the Gulf of Mexico. We measured MeHg and total Hg (THg) concentrations, and ancillary chemical characteristics, in whole and filtered surface water, and filtered porewater. Overall, MeHg concentrations were greatest in surface water of freshwater wetlands and lowest in the profundal (non-vegetated) regions of the lake and river mainstems. Concentrations of THg and MeHg in filtered surface water were positively correlated with the highly reactive, aromatic (hydrophobic organic acid) fraction of dissolved organic carbon (DOC). These results suggest that DOC plays an important role in promoting the mobility, transport and bioavailability of inorganic Hg in these environments. Further, elevated porewater concentrations in marine and brackish wetlands suggest coastal wetlands along the Gulf Coast are key sites for MeHg production and may be a principal source of MeHg to foodwebs in the Gulf of Mexico. Examining the relationships among MeHg, THg, and DOC across these multiple landscape types is a first step in evaluating possible links between key zones for

Classifications for Coastal Wetlands Planning, Protection and Restoration Act site-specific projects: 2008 and 2009

Science.gov (United States)

Jones, William R.; Garber, Adrienne

2012-01-01

The Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) funds over 100 wetland restoration projects across Louisiana. Integral to the success of CWPPRA is its long-term monitoring program, which enables State and Federal agencies to determine the effectiveness of each restoration effort. One component of this monitoring program is the analysis of high-resolution, color-infrared aerial photography at the U.S. Geological Survey's National Wetlands Research Center in Lafayette, Louisiana. Color-infrared aerial photography (9- by 9-inch) is obtained before project construction and several times after construction. Each frame is scanned on a photogrametric scanner that produces a high-resolution image in Tagged Image File Format (TIFF). By using image-processing software, these TIFF files are then orthorectified and mosaicked to produce a seamless image of a project area and its associated reference area (a control site near the project that has common environmental features, such as marsh type, soil types, and water salinities.) The project and reference areas are then classified according to pixel value into two distinct classes, land and water. After initial land and water ratios have been established by using photography obtained before and after project construction, subsequent comparisons can be made over time to determine land-water change. Several challenges are associated with the land-water interpretation process. Primarily, land-water classifications are often complicated by the presence of floating aquatic vegetation that occurs throughout the freshwater systems of coastal Louisiana and that is sometimes difficult to differentiate from emergent marsh. Other challenges include tidal fluctuations and water movement from strong winds, which may result in flooding and inundation of emergent marsh during certain conditions. Compensating for these events is difficult but possible by using other sources of imagery to verify marsh conditions for other

77 FR 17037 - Intent To Prepare a Draft Environmental Impact Statement for the Louisiana Coastal Area (LCA...

Science.gov (United States)

2012-03-23

... Environmental Impact Statement for the Louisiana Coastal Area (LCA)--Louisiana, Mississippi River Hydrodynamic... impact statement (EIS) for the Louisiana Coastal Area (LCA)--Louisiana, Mississippi River Hydrodynamic... tiered off of the November 2004, programmatic EIS for the Louisiana Coastal Area (LCA), Louisiana...

Analysis of change in marsh types of coastal Louisiana, 1978-2001

Science.gov (United States)

Linscombe, Robert G.; Hartley, Stephen B.

2011-01-01

may or may not have made up for a dry period during the earlier 12 months. More research is needed to better understand rainfall periods and how they affect salinity changes. The ability to understand past dynamics and to anticipate future trends in vegetation change and related land loss in the coastal region of Louisiana is a vital part of ongoing and future efforts to conserve its critical wetland ecosystem. With the loss of marsh and resultant changes in hydrology, it is likely that changes in marsh type may show greater variation in the future, even if given only minor changes in precipitation levels.

Louisiana Coastal Zone Boundary, Geographic NAD83, LDNR (1998)[coastal_zone_boundary_LDNR_1998

Data.gov (United States)

Louisiana Geographic Information Center — This is a polygon dataset representing the extent of the LDNR regulatory area defined as the Louisiana Coastal Zone. This area comprises a band across the southern...

Utilizing NASA Earth Observing System (EOS) Data to Determine Ideal Planting Locations for Wetland Tree Species in St. Bernard Parish, Louisiana

Science.gov (United States)

Reahard, Ross; Arguelles, Maria; Strong, Emma; Ewing, Michael; Kelly, Chelsey

2012-01-01

St. Bernard Parish, in southeast Louisiana, is rapidly losing coastal forests and wetlands due to a combination of natural and anthropogenic disturbances (e.g. subsidence, saltwater intrusion, low sedimentation, nutrient deficiency, herbivory, canal dredging, levee construction, spread of invasive species, etc.). After Hurricane Katrina severely impacted the area in 2005, multiple Non-Governmental Organizations (NGOs) have worked not only on rebuilding destroyed dwellings, but on rebuilding the ecosystems that once protected the citizens of St. Bernard Parish. Volunteer groups, NGOs, and government entities often work separately and independently of each other and use different sets of information to choose the best planting sites for coastal forests. Using NASA EOS, NRCS soil surveys, and ancillary road and canal data in conjunction with ground truthing, the team created maps of optimal planting sites for several species of wetland trees to aid in unifying these organizations, who share a common goal, under one plan. The methodology for this project created a comprehensive Geographic Information System (GIS) to help identify suitable planting sites in St. Bernard Parish. This included supplementing existing elevation data using LIDAR data and classifying existing land cover in the study area from ASTER multispectral satellite data. Low altitude AVIRIS hyperspectral imagery was used to assess the health of vegetation over an area near the intersection of the Mississippi River Gulf Outlet Canal (MRGO) and Bayou la Loutre. Historic extent of coastal forests was mapped using aerial photos from USGS collected between 1952 and 1956. The final products demonstrated the utility of combining NASA EOS with other geospatial data in assessing, monitoring, and restoring of coastal ecosystems in Louisiana. This methodology also provides a useful template for other ecological forecasting and coastal restoration applications.

Water quality of a coastal Louisiana swamp and how dredging is undermining restoration efforts

Science.gov (United States)

Lane, Robert R.; Huang, Haosheng; Day, John W.; Justic, Dubravko; DeLaune, Ronald D.

2015-01-01

The Bayou Boeuf Basin (BBB), a sub-basin of the Barataria Basin estuary in coastal Louisiana, consists of forested and floating wetlands receiving drainage from surrounding agricultural fields and urban watersheds. We characterized surface water quality in the BBB, and determined through hydrologic modeling if a series of levee breaks along major drainage channels would significantly improve water quality by allowing flow into surrounding wetlands. Surface water monitoring found surrounding sugarcane farm fields to be major sources of nutrient and sediment loading. Hydrological modeling indicated that levee breaks would increase N reduction from the current 21.4% to only 29.2%, which is much lower than the anticipated 90-100% removal rate. This was due to several factors, one them being dredging of main drainage channels to such a degree that water levels do not rise much above the surrounding wetland elevation even during severe storms, so only a very small fraction of the stormwater carried in the channel is exposed to wetlands. These unexpected results provide insight into an undoubtedly pervasive problem in human dominated wetland systems; that of decreased flooding during storm events due to channel deepening by dredging activities. Additional water quality management practices should be implemented at the farm field level, prior to water entering major drainage canals.

Coastal wetlands: an integrated ecosystem approach

Science.gov (United States)

Perillo, G. M. E.; Wolanski, E.; Cahoon, D.R.; Brinson, M.M.

2009-01-01

Coastal wetlands are under a great deal of pressure from the dual forces of rising sea level and the intervention of human populations both along the estuary and in the river catchment. Direct impacts include the destruction or degradation of wetlands from land reclamation and infrastructures. Indirect impacts derive from the discharge of pollutants, changes in river flows and sediment supplies, land clearing, and dam operations. As sea level rises, coastal wetlands in most areas of the world migrate landward to occupy former uplands. The competition of these lands from human development is intensifying, making the landward migration impossible in many cases. This book provides an understanding of the functioning of coastal ecosystems and the ecological services that they provide, and suggestions for their management. In this book a CD is included containing color figures of wetlands and estuaries in different parts of the world.

Ecology of tidal freshwater forests in coastal deltaic Louisiana and northeastern South Carolina: Chapter 9

Science.gov (United States)

Conner, William H.; Krauss, Ken W.; Doyle, Thomas W.

2007-01-01

Tidal freshwater swamps in the southeastern United States are subjected to tidal hydroperiods ranging in amplitude from microtidal (forests, scrub-shrub stands, marsh, or open water but are less likely to convert mesotidal swamps. Changes to hydrological patterns tend to be more noticeable in Louisiana than do those in South Carolina.The majority of Louisiana’s coastal wetland forests are found in the Mississippi River deltaic plain region. Coastal wetland forests in the deltaic plain have been shaped by the sediments, water, and energy of the Mississippi River and its major distributaries. Baldcypress (Taxodium distichum [L.] L.C. Rich.) and water tupelo (Nyssa aquatica L.) are the primary tree species in the coastal swamp forests of Louisiana. Sites where these species grow usually hold water for most of the year; however, some of the more seaward sites were historically microtidal, especially where baldcypress currently dominates. In many other locations, baldcypress and water tupelo typically grow in more or less pure stands or as mixtures of the two with common associates such as black willow (Salix nigra Marsh.), red maple (Acer rubrum L.), water locust (Gleditsia aquatic Marsh.), overcup oak (Quercus lyrata Walt.), water hickory (Carya aquatica [Michx. f.] Nutt.), green ash (Fraxinus pennsylvanica Marsh.), pumpkin ash (F. profunda Bush.), and redbay (Persea borbonia [L.] Sprengel) (Brown and Montz 1986).The South Carolina coastal plain occupies about two-thirds of the state and rises gently to 150 m from the Atlantic Ocean up to the Piedmont plateau. Many rivers can be found in the Coastal Plain with swamps near the coast that extend inland along the rivers. Strongly tidal freshwater forests occur along the lower reaches of redwater rivers (Santee, Great Pee Dee, and Savannah) that arise in the mountains and along the numerous blackwater rivers (Ashepoo, Combahee, Cooper, and Waccamaw) that arise in the coastal regions. Most of the tidal freshwater forests

Denitrification potential and its relation to organic carbon quality in three coastal wetland soils

International Nuclear Information System (INIS)

Dodla, Syam K.; Wang, Jim J.; DeLaune, Ron D.; Cook, Robert L.

2008-01-01

Capacity of a wetland to remove nitrate through denitrification is controlled by its physico-chemical and biological characteristics. Understanding these characteristics will help better to guide beneficial use of wetlands in processing nitrate. This study was conducted to determine the relationship between soil organic carbon (SOC) quality and denitrification rate in Louisiana coastal wetlands. Composite soil samples of different depths were collected from three different wetlands along a salinity gradient, namely, bottomland forest swamp (FS), freshwater marsh (FM), and saline marsh (SM) located in the Barataria Basin estuary. Potential denitrification rate (PDR) was measured by acetylene inhibition method and distribution of carbon (C) moieties in organic C was determined by 13 C solid-state NMR. Of the three wetlands, the FM soil profile exhibited the highest PDR on both unit weight and unit volume basis as compared to FS and SM. The FM also tended to yield higher amount of N 2 O as compared to the FS and SM especially at earlier stages of denitrification, suggesting incomplete reduction of NO 3 - at FM and potential for emission of N 2 O. Saline marsh soil profile had the lowest PDR on the unit volume basis. Increasing incubation concentration from 2 to 10 mg NO 3 - -N L -1 increased PDR by 2 to 6 fold with the highest increase in the top horizons of FS and SM soils. Regression analysis showed that across these three wetland systems, organic C has significant effect in regulating PDR. Of the compositional C moieties, polysaccharides positively influenced denitrification rate whereas phenolics (likely phenolic adehydes and ketonics) negatively affected denitrification rate in these wetland soils. These results could have significant implication in integrated assessment and management of wetlands for treating nutrient-rich biosolids and wastewaters, non-point source agricultural runoff, and nitrate found in the diverted Mississippi River water used for coastal

Settling characteristics of fine-grained sediments used in Louisiana coastal land building and restoration projects

Science.gov (United States)

Ghose Hajra, M.

2016-02-01

Coastal property development, sea level rise, geologic subsidence, loss of barrier islands, increasing number and intensity of coastal storms and other factors have resulted in water quality degradation, wetlands loss, reduced storm and surge protection, ground settlement, and other challenges in coastal areas throughout the world. One of the goals towards reestablishing a healthy coastal ecosystem is to rebuild wetlands with river diversion or sediment conveyance projects that optimally manage and allocate sediments, minimally impact native flora and fauna, and positively affect the water quality. Engineering properties and material characteristics of the dredged material and foundation soils are input parameters in several mathematical models used to predict the long term behavior of the dredged material and foundation soil. Therefore, proper characterization of the dredged material and foundation soils is of utmost importance in the correct design of a coastal restoration and land reclamation project. The sedimentation and consolidation characteristics of the dredged material as well as their effects on the time rate of settlement of the suspended solid particles and underlying foundation soil depend, among other factors, on the (a) grain size distribution of the dredged material, (b) salinity (fresh, brackish, or saltwater environment) of the composite slurry, and (c) concentration of the solid particles in the slurry. This paper will present the results from column settling tests and self-weight consolidation tests performed on dredged samples obtained from actual restoration projects in Louisiana. The effects of salinity, grain size distribution, and initial particle concentration on the sedimentation and consolidation parameters of the dredged material will also be discussed.

Satellite Images and Aerial Photographs of the Effects of Hurricanes Katrina and Rita on Coastal Louisiana

Science.gov (United States)

Barras, John A.

2007-01-01

Introduction Hurricane Katrina made landfall on the eastern coastline of Louisiana on August 29, 2005; Hurricane Rita made landfall on the western coastline of Louisiana on September 24, 2005. Comparison of Landsat Thematic Mapper (TM) satellite imagery acquired before and after the landfalls of Katrina and Rita and classified to identify land and water demonstrated that water area increased by 217 mi2 (562 km2) in coastal Louisiana as a result of the storms. Approximately 82 mi2 (212 km2) of new water areas were in areas primarily impacted by Hurricane Katrina (Mississippi River Delta basin, Breton Sound basin, Pontchartrain basin, and Pearl River basin), whereas 99 mi2 (256 km2) were in areas primarily impacted by Hurricane Rita (Calcasieu/Sabine basin, Mermentau basin, Teche/Vermilion basin, Atchafalaya basin, and Terrebonne basin). Barataria basin contained new water areas caused by both hurricanes, resulting in some 18 mi2 (46.6 km2) of new water areas. The fresh marsh and intermediate marsh communities' land areas decreased by 122 mi2 (316 km2) and 90 mi2 (233.1 km2), respectively, and the brackish marsh and saline marsh communities' land areas decreased by 33 mi2 (85.5 km2) and 28 mi2 (72.5 km2), respectively. These new water areas represent land losses caused by direct removal of wetlands. They also indicate transitory changes in water area caused by remnant flooding, removal of aquatic vegetation, scouring of marsh vegetation, and water-level variation attributed to normal tidal and meteorological variation between satellite images. Permanent losses cannot be estimated until several growing seasons have passed and the transitory impacts of the hurricanes are minimized. The purpose of this study was to provide preliminary information on water area changes in coastal Louisiana acquired shortly after the landfalls of both hurricanes (detectable with Landsat TM imagery) and to serve as a regional baseline for monitoring posthurricane wetland recovery. The land

Identification of Transportation Infrastructure at Risk Due To Sea-Level Rise and Subsidence of Land In Coastal Louisiana

Science.gov (United States)

Tewari, S.; Palmer, W.; Manning, F.

2017-12-01

Climate change can affect coastal areas in a variety of ways. Coasts are sensitive to sea level rise, changes in the frequency/intensity of storms, increase in precipitation and storm surges. The resilience of transportation infrastructure located in Louisiana's coastal zone, against storm surges and climatic sea-level rise is critical. The net change in sea-level is affected by the increase in global sea level as well as land movement up or down. There are many places in coastal Louisiana that have a high subsidence rate. The subsidence could be related to excess extraction activities of oil and water, natural and/or human induced compaction, and tectonic movement. Where the land is sinking, the rate of relative sea level rise is larger than the global rate. Some of the fastest rates of relative sea level rise in the United States are occurring in areas where the land is sinking, including parts of the Gulf Coast. For example, coastal Louisiana has seen its relative sea level rise by eight inches or more in the last 50 years, which is about twice the global rate. Subsiding land in the Gulf area worsens the effects of relative sea level rise, increasing the risk of flooding in cities, inhabited islands, and tidal wetlands. The research team is investigating the trends for sea-level rise and land subsidence in coastal region of Louisiana. The variability in storm surges and its potential implication on the transportation infrastructure in the region is the focus of the study. The spatial maps will be created for spatial trends. This is extremely useful in being prepared for long-term natural hazards. The results of this study will be helpful to LADOTD and infrastructure managers and officials who are tasked with resiliency planning and management. Research results will also directly benefit university researchers in the state, Coastal Protection and Restoration Authority and LADOTD/LTRC through collaborative activity which will educate both professionals and the

China's coastal wetlands: conservation history, implementation efforts, existing issues and strategies for future improvement.

Science.gov (United States)

Sun, Zhigao; Sun, Wenguang; Tong, Chuan; Zeng, Congsheng; Yu, Xiang; Mou, Xiaojie

2015-06-01

China has approximately 5.80×10(6)ha coastal wetlands by 2014, accounting for 10.82% of the total area of natural wetlands. Healthy coastal wetland ecosystems play an important role in guaranteeing the territory ecological security and the sustainable development of coastal zone in China. In this paper, the natural geography and the past and present status of China's coastal wetlands were introduced and the five stages (1950s-1970s, 1980s-1991, 1992-2002, 2003-2010 and 2011-present) of China's coastal wetlands conservation from the foundation of the People's Republic in 1949 to present were distinguished and reviewed. Over the past decades, China has made great efforts in coastal wetland conservation, as signified by the implementation of coastal wetland restoration projects, the construction of coastal wetland nature reserves, the practice of routine ecological monitoring and two national wetland surveys, the promulgation of local wetland conservation statutes and specific regulations, the coordination mechanism to enhance management capacity, the wide development of coastal wetland research and public participation, and the extensive communication to strengthen international cooperation. Nonetheless, six major issues recently emerged in China's coastal wetland conservation are evidently existed, including the increasing threats of pollution and human activities, the increasing adverse effects of threaten factors on ecosystem function, the increasing threats of coastal erosion and sea-level rising, the insufficient funding for coastal wetlands conservation, the imperfect legal and management system for coastal wetlands, and the insufficient education, research and international cooperation. Although the threats and pressures on coastal wetlands conservation are still apparent, the future of China's coastal wetlands looks promising since the Chinese government understands that the sustainable development in coastal zone requires new attitudes, sound policies and

Coastal Wetland Restoration Bibliography

National Research Council Canada - National Science Library

Yozzo, David

1997-01-01

This bibliography was compiled to provide biologists, engineers, and planners at Corps Districts and other agencies/ institutions with a guide to the diverse body of literature on coastal wetland restoration...

Assessing coastal wetland vulnerability to sea-level rise along the northern Gulf of Mexico coast: Gaps and opportunities for developing a coordinated regional sampling network.

Science.gov (United States)

Osland, Michael J; Griffith, Kereen T; Larriviere, Jack C; Feher, Laura C; Cahoon, Donald R; Enwright, Nicholas M; Oster, David A; Tirpak, John M; Woodrey, Mark S; Collini, Renee C; Baustian, Joseph J; Breithaupt, Joshua L; Cherry, Julia A; Conrad, Jeremy R; Cormier, Nicole; Coronado-Molina, Carlos A; Donoghue, Joseph F; Graham, Sean A; Harper, Jennifer W; Hester, Mark W; Howard, Rebecca J; Krauss, Ken W; Kroes, Daniel E; Lane, Robert R; McKee, Karen L; Mendelssohn, Irving A; Middleton, Beth A; Moon, Jena A; Piazza, Sarai C; Rankin, Nicole M; Sklar, Fred H; Steyer, Greg D; Swanson, Kathleen M; Swarzenski, Christopher M; Vervaeke, William C; Willis, Jonathan M; Wilson, K Van

2017-01-01

Coastal wetland responses to sea-level rise are greatly influenced by biogeomorphic processes that affect wetland surface elevation. Small changes in elevation relative to sea level can lead to comparatively large changes in ecosystem structure, function, and stability. The surface elevation table-marker horizon (SET-MH) approach is being used globally to quantify the relative contributions of processes affecting wetland elevation change. Historically, SET-MH measurements have been obtained at local scales to address site-specific research questions. However, in the face of accelerated sea-level rise, there is an increasing need for elevation change network data that can be incorporated into regional ecological models and vulnerability assessments. In particular, there is a need for long-term, high-temporal resolution data that are strategically distributed across ecologically-relevant abiotic gradients. Here, we quantify the distribution of SET-MH stations along the northern Gulf of Mexico coast (USA) across political boundaries (states), wetland habitats, and ecologically-relevant abiotic gradients (i.e., gradients in temperature, precipitation, elevation, and relative sea-level rise). Our analyses identify areas with high SET-MH station densities as well as areas with notable gaps. Salt marshes, intermediate elevations, and colder areas with high rainfall have a high number of stations, while salt flat ecosystems, certain elevation zones, the mangrove-marsh ecotone, and hypersaline coastal areas with low rainfall have fewer stations. Due to rapid rates of wetland loss and relative sea-level rise, the state of Louisiana has the most extensive SET-MH station network in the region, and we provide several recent examples where data from Louisiana's network have been used to assess and compare wetland vulnerability to sea-level rise. Our findings represent the first attempt to examine spatial gaps in SET-MH coverage across abiotic gradients. Our analyses can be used

An Effort to Map and Monitor Baldcypress Forest Areas in Coastal Louisiana, Using Landsat, MODIS, and ASTER Satellite Data

Science.gov (United States)

Spruce, Joseph P.; Sader, Steve; Smoot, James

2012-01-01

This presentation discusses a collaborative project to develop, test, and demonstrate baldcypress forest mapping and monitoring products for aiding forest conservation and restoration in coastal Louisiana. Low lying coastal forests in the region are being negatively impacted by multiple factors, including subsidence, salt water intrusion, sea level rise, persistent flooding, hydrologic modification, annual insect-induced forest defoliation, timber harvesting, and conversion to urban land uses. Coastal baldcypress forests provide invaluable ecological services in terms of wildlife habitat, forest products, storm buffers, and water quality benefits. Before this project, current maps of baldcypress forest concentrations and change did not exist or were out of date. In response, this project was initiated to produce: 1) current maps showing the extent and location of baldcypress dominated forests; and 2) wetland forest change maps showing temporary and persistent disturbance and loss since the early 1970s. Project products are being developed collaboratively with multiple state and federal agencies. Products are being validated using available reference data from aerial, satellite, and field survey data. Results include Landsat TM- based classifications of baldcypress in terms of cover type and percent canopy cover. Landsat MSS data was employed to compute a circa 1972 classification of swamp and bottomland hardwood forest types. Landsat data for 1972-2010 was used to compute wetland forest change products. MODIS-based change products were applied to view and assess insect-induced swamp forest defoliation. MODIS, Landsat, and ASTER satellite data products were used to help assess hurricane and flood impacts to coastal wetland forests in the region.

Lake Superior Coastal Wetland Fish Assemblages and ...

Science.gov (United States)

The role of the coastal margin and the watershed context in defining the ecology of even very large lakes is increasingly being recognized and examined. Coastal wetlands are both important contributors to the biodiversity and productivity of large lakes and important mediators of the lake-basin connection. We explored wetland-watershed connections and their relationship to wetland function and condition using data collected from 37 Lake Superior wetlands spanning a substantial geographic and geomorphic gradient. While none of these wetlands are particularly disturbed, there were nevertheless clear relationships between watershed landuse and wetland habitat and biota, and these varied consistently across wetland type categories that reflected the strength of connection to the watershed. For example, water clarity and vegetation structure complexity declined with decreasing percent natural land cover, and these effects were strongest in riverine wetlands (having generally large watersheds and tributary-dominated hydrology) and weakest in lagoon wetlands (having generally small watersheds and lake-dominate hydrology). Fish abundance and species richness both increased with decreasing percent natural land cover while species diversity decreased, and again the effect was strongest in riverine wetlands. Lagoonal wetlands, which lack any substantial tributary, consistently harbored the fewest species of fish and a composition different from the more watershed-lin

A Dutch Perspective on Coastal Louisiana Flood Risk Reduction and Landscape Stabilization

National Research Council Canada - National Science Library

Dijkman, Jos

2007-01-01

.... The project was aimed at identifying options for the long-term reduction of flood risks and landscape stabilization in Planning Areas I and 2 in Louisiana, in the framework of the Louisiana Coastal...

Denitrification potential and its relation to organic carbon quality in three coastal wetland soils

Energy Technology Data Exchange (ETDEWEB)

Dodla, Syam K. [School of Plant, Environmental and Soil Sciences, Louisiana State Univ. Agricultural Center, Baton Rouge, LA 70803 (United States); Wang, Jim J. [School of Plant, Environmental and Soil Sciences, Louisiana State Univ. Agricultural Center, Baton Rouge, LA 70803 (United States)], E-mail: jjwang@agctr.lsu.edu; DeLaune, Ron D. [Wetland Biogeochemistry Institute, School of the Coast and Environment, Louisiana State University, Baton Rouge, LA 70803 (United States); Cook, Robert L. [Chemistry Department, Louisiana State University, Baton Rouge, LA 70803 (United States)

2008-12-15

Capacity of a wetland to remove nitrate through denitrification is controlled by its physico-chemical and biological characteristics. Understanding these characteristics will help better to guide beneficial use of wetlands in processing nitrate. This study was conducted to determine the relationship between soil organic carbon (SOC) quality and denitrification rate in Louisiana coastal wetlands. Composite soil samples of different depths were collected from three different wetlands along a salinity gradient, namely, bottomland forest swamp (FS), freshwater marsh (FM), and saline marsh (SM) located in the Barataria Basin estuary. Potential denitrification rate (PDR) was measured by acetylene inhibition method and distribution of carbon (C) moieties in organic C was determined by {sup 13}C solid-state NMR. Of the three wetlands, the FM soil profile exhibited the highest PDR on both unit weight and unit volume basis as compared to FS and SM. The FM also tended to yield higher amount of N{sub 2}O as compared to the FS and SM especially at earlier stages of denitrification, suggesting incomplete reduction of NO{sub 3}{sup -} at FM and potential for emission of N{sub 2}O. Saline marsh soil profile had the lowest PDR on the unit volume basis. Increasing incubation concentration from 2 to 10 mg NO{sub 3}{sup -}-N L{sup -1} increased PDR by 2 to 6 fold with the highest increase in the top horizons of FS and SM soils. Regression analysis showed that across these three wetland systems, organic C has significant effect in regulating PDR. Of the compositional C moieties, polysaccharides positively influenced denitrification rate whereas phenolics (likely phenolic adehydes and ketonics) negatively affected denitrification rate in these wetland soils. These results could have significant implication in integrated assessment and management of wetlands for treating nutrient-rich biosolids and wastewaters, non-point source agricultural runoff, and nitrate found in the diverted

Coastal Wetlands Protection Act: Case of Apalachicola-Chattahoochee-Flint (ACF River

Directory of Open Access Journals (Sweden)

Latif Gürkan KAYA

2007-01-01

Full Text Available Coastal wetlands, being important components of estuarine and coastal systems, stand for all publicly owned lands subject to the ebb and flow of the tide. They are below the watermark of ordinary high tide. The coastal wetlands contain a vital natural resource system. The coastal wetlands resource system, unless impossible, to reconstruct or rehabilitate once adversely affected by human. In the USA, the Apalachicola-Chattahoochee-Flint (ACF river states (i.e. Georgia, Alabama and Florida have variation in the structure and the function of their wetland program affecting the ACF river basins' wetlands. Although some states have no special wetlands program, they have permits and water quality certification for these areas. Some state programs affect state agencies while local government implements other programs.

Offshore Oil and Gas Platforms for Coastal Louisiana, UTM Zone 15N NAD83, Louisiana Recovery Authority (2007), [offshore_platforms_2006

Data.gov (United States)

Louisiana Geographic Information Center — This data set was originally produced by the Coastal Management Division (CMD) of the Louisiana Department of Natural Resources in a cooperative agreement with the...

Methane emissions from different coastal wetlands in New England, US

Science.gov (United States)

Wang, F.; Tang, J.; Kroeger, K. D.; Gonneea, M. E.

2017-12-01

According to the IPCC, methane have 25 times warming effect than CO2, and natural wetlands contribute 20-39 % to the global emission of methane. Although most of these methane was from inland wetlands, there was still large uncertain in the methane emissions in coastal wetlands. In the past three years, we have investigated methane emissions in coastal wetlands in MA, USA. Contrary to previous assumptions, we have observed relative larger methane flux in some salt marshes than freshwater wetlands. We further detect the methane source, and found that plant activities played an important role in methane flux, for example, the growth of S. aterniflora, the dominate plants in salt marsh, could enhance methane emission, while in an fresh water wetland that was dominated by cattail, plant activity oxided methane and reduced total flux. Phragmite, an invasive plant at brackish marsh, have the highest methane flux among all coastal wetland investigated. This study indicated that coastal wetland could still emit relatively high amount of methane even under high water salinity condiations, and plant activity played an important role in methane flux, and this role was highly species-specific.

Radar geomorphology of coastal and wetland environments

Science.gov (United States)

Lewis, A. J.; Macdonald, H. C.

1973-01-01

Details regarding the collection of radar imagery over the past ten years are considered together with the geomorphic, geologic, and hydrologic data which have been extracted from radar imagery. Recent investigations were conducted of the Louisiana swamp marsh and the Oregon coast. It was found that radar imagery is a useful tool to the scientist involved in wetland research.

Coastal Wetlands Protection Act: Case of Apalachicola-Chattahoochee-Flint (ACF) River

OpenAIRE

Latif Gürkan KAYA

2007-01-01

Coastal wetlands, being important components of estuarine and coastal systems, stand for all publicly owned lands subject to the ebb and flow of the tide. They are below the watermark of ordinary high tide. The coastal wetlands contain a vital natural resource system. The coastal wetlands resource system, unless impossible, to reconstruct or rehabilitate once adversely affected by human. In the USA, the Apalachicola-Chattahoochee-Flint (ACF) river states (i.e. Georgia, Alabama and Florida) ha...

Assessing coastal wetland vulnerability to sea-level rise along the northern Gulf of Mexico coast: Gaps and opportunities for developing a coordinated regional sampling network.

Directory of Open Access Journals (Sweden)

Michael J Osland

Full Text Available Coastal wetland responses to sea-level rise are greatly influenced by biogeomorphic processes that affect wetland surface elevation. Small changes in elevation relative to sea level can lead to comparatively large changes in ecosystem structure, function, and stability. The surface elevation table-marker horizon (SET-MH approach is being used globally to quantify the relative contributions of processes affecting wetland elevation change. Historically, SET-MH measurements have been obtained at local scales to address site-specific research questions. However, in the face of accelerated sea-level rise, there is an increasing need for elevation change network data that can be incorporated into regional ecological models and vulnerability assessments. In particular, there is a need for long-term, high-temporal resolution data that are strategically distributed across ecologically-relevant abiotic gradients. Here, we quantify the distribution of SET-MH stations along the northern Gulf of Mexico coast (USA across political boundaries (states, wetland habitats, and ecologically-relevant abiotic gradients (i.e., gradients in temperature, precipitation, elevation, and relative sea-level rise. Our analyses identify areas with high SET-MH station densities as well as areas with notable gaps. Salt marshes, intermediate elevations, and colder areas with high rainfall have a high number of stations, while salt flat ecosystems, certain elevation zones, the mangrove-marsh ecotone, and hypersaline coastal areas with low rainfall have fewer stations. Due to rapid rates of wetland loss and relative sea-level rise, the state of Louisiana has the most extensive SET-MH station network in the region, and we provide several recent examples where data from Louisiana's network have been used to assess and compare wetland vulnerability to sea-level rise. Our findings represent the first attempt to examine spatial gaps in SET-MH coverage across abiotic gradients. Our

A meta-analysis of coastal wetland ecosystem services in Liaoning Province, China

Science.gov (United States)

Sun, Baodi; Cui, Lijuan; Li, Wei; Kang, Xiaoming; Pan, Xu; Lei, Yinru

2018-01-01

Wetlands are impacted by economic and political initiatives, and their ecosystem services are attracting increasing public attention. It is crucial that management decisions for wetland ecosystem services quantify the economic value of the ecosystem services. In this paper, we aimed to estimate a monetary value for coastal wetland ecosystem services in Liaoning Province, China. We selected 433 observations from 85 previous coastal wetland economic evaluations (mostly in China) including detailed spatial and economic characteristics in each wetland, then used a meta-analysis scale transfer method to calculate the total value of coastal wetland ecosystem services in Liaoning Province. Our results demonstrated that, on average, the ecosystem services provided by seven different coastal wetland types were worth US40,648 per ha per year, and the total value was 28,990,439,041 in 2013. Shallow marine waters accounted for the largest proportion (83.97%). Variables with a significant positive effect on the ecosystem service values included GDP per capita, population density, distance from the wetland to the city center and the year of evaluation, while wetland size and latitude had negative relationships.

2011 Summary: Coastal wetland restoration research

Science.gov (United States)

Kowalski, Kurt P.; Wiley, Michael J.; Wilcox, Douglas A.; Carlson Mazur, Martha L.; Czayka, Alex; Dominguez, Andrea; Doty, Susan; Eggleston, Mike; Green, Sean; Sweetman, Amanda

2014-01-01

The Great Lakes Restoration Initiative (GLRI) projects currently taking place in Great Lakes coastal wetlands provide a unique opportunity to study ecosystem response to management actions as practitioners strive to improve wetland function and increase ecosystem services. Through a partnership between the U.S. Geological Survey – Great Lakes Science Center (GLSC), U.S. Fish and Wildlife Service (USFWS), and Ducks Unlimited, a GLRI-funded project has reestablished the hydrologic connection between an intensively managed impounded wetland (Pool 2B) and Crane Creek, a small Lake Erie tributary, by building a water-control structure that was opened in the spring of 2011. The study site is located within the USFWS Ottawa National Wildlife Refuge (ONWR) and lies within the boundaries of the U.S. Environmental Protection Agency (EPA)-designated Maumee River Area of Concern. The broad objective of the project is to evaluate how hydrologically reconnecting a previously diked wetland impacts fish, mollusks, and other biota and affects nutrient transport, nutrient cycling, water quality, flood storage, and many other abiotic conditions. The results from this project suggest large system-wide benefits from sustainable reestablishment of lake-driven hydrology in this and other similar systems. We comprehensively sampled water chemistry, fish, birds, plants, and invertebrates in Crane Creek coastal wetlands, Pool 2A (a reference diked wetland), and Pool 2B (the reconnected wetland) in 2010 and 2011 to: 1) Characterize spatial and seasonal patterns for these parameters. 2) Examine ecosystem response to the opening of a water-control structure that allows fish passage Our sampling efforts have yielded data that reveal striking changes in water quality, hydrology, and fish assemblages in our experimental unit (2B). Prior to the reconnection, the water chemistry in pools 2A and 2B were very similar. Afterwards, we found that the water chemistry in reconnected Pool 2B was more

Predictive occurrence models for coastal wetland plant communities: Delineating hydrologic response surfaces with multinomial logistic regression

Science.gov (United States)

Snedden, Gregg A.; Steyer, Gregory D.

2013-02-01

Understanding plant community zonation along estuarine stress gradients is critical for effective conservation and restoration of coastal wetland ecosystems. We related the presence of plant community types to estuarine hydrology at 173 sites across coastal Louisiana. Percent relative cover by species was assessed at each site near the end of the growing season in 2008, and hourly water level and salinity were recorded at each site Oct 2007-Sep 2008. Nine plant community types were delineated with k-means clustering, and indicator species were identified for each of the community types with indicator species analysis. An inverse relation between salinity and species diversity was observed. Canonical correspondence analysis (CCA) effectively segregated the sites across ordination space by community type, and indicated that salinity and tidal amplitude were both important drivers of vegetation composition. Multinomial logistic regression (MLR) and Akaike's Information Criterion (AIC) were used to predict the probability of occurrence of the nine vegetation communities as a function of salinity and tidal amplitude, and probability surfaces obtained from the MLR model corroborated the CCA results. The weighted kappa statistic, calculated from the confusion matrix of predicted versus actual community types, was 0.7 and indicated good agreement between observed community types and model predictions. Our results suggest that models based on a few key hydrologic variables can be valuable tools for predicting vegetation community development when restoring and managing coastal wetlands.

Balancing Methane Emissions and Carbon Sequestration in Tropical/Subtropical Coastal Wetlands: A Review

Science.gov (United States)

Mitsch, W. J.; Schafer, K. V.; Cabezas, A.; Bernal, B.

2016-02-01

Wetlands are estimated to emit about 20 to 25 percent of current global CH4 emissions, or about 120 to 180 Tg-CH4 yr-1. Thus, in climate change discussions concerning wetlands, these "natural emissions" often receive the most attention, often overshadowing the more important ecosystem services that wetlands provide, including carbon sequestration. While methane emissions from coastal wetlands have generally been described as small due to competing biogeochemical cycles, disturbance of coastal wetlands, e.g., the introduction of excessive freshwater fluxes or substrate disturbance, can lead to much higher methane emission rates. Carbon sequestration is a more positive carbon story about wetlands and coastal wetlands in particular. The rates of carbon sequestration in tropical/subtropical coastal wetlands, mainly mangroves, are in the range of 100 to 200 g-C m-2 yr-1, two to ten times higher rates than in the more frequently studied northern peatlands. This function of coastal wetlands has significant international support now for mangrove conservation and it is referred to in the literature and popular press as blue carbon. This presentation will summarize what we know about methane emissions and carbon sequestration in tropical/subtropical coastal wetlands, how these rates compare with those in non-tropical and/or inland wetlands, and a demonstration of two or three models that compare methane fluxes with carbon dioxide sequestration to determine if wetlands are net sinks of radiative forcing. The presentation will also present a global model of carbon with an emphasis on wetlands.

The landscape pattern characteristics of coastal wetlands in Jiaozhou Bay under the impact of human activities.

Science.gov (United States)

Gu, Dongqi; Zhang, Yuanzhi; Fu, Jun; Zhang, Xuliang

2007-01-01

In this study, we interpreted coastal wetland types from an ASTER satellite image in 2002, and then compared the results with the land-use status of coastal wetlands in 1952 to determine the wetland loss and degradation around Jiaozhou Bay. Seven types of wetland landscape were classified, namely: shallow open water, inter-tidal flats, estuarine water, brackish marshes, salt ponds, fishery ponds and ports. Several landscape pattern indices were analysed: the results indicate that the coastal wetlands have been seriously degraded. More and more natural wetlands have been transformed into artificial wetlands, which covered about 33.7% of the total wetlands in 2002. In addition, we used a defined model to assess the impacts of human activities on coastal wetlands. The results obtained show that the coastal wetlands of Jiaozhou Bay have suffered severe human disturbance. Effective coastal management and control is therefore needed to solve the issues of the coastal wetland loss and degradation existing in this area.

Understanding the Hydrodynamics of a Coastal Wetland with an Integrated Distributed Model

Science.gov (United States)

Zhang, Y.; Li, W.; Sun, G.

2017-12-01

Coastal wetlands linking ocean and terrestrial landscape provide important ecosystem services including flood mitigation, fresh water supply, erosion control, carbon sequestration, and wildlife habitats. Wetland hydrology is the major driving force for wetland formation, structure, function, and ecosystem services. The dynamics of wetland hydrology and energy budget are strongly affected by frequent inundation and drying of wetland soil and vegetation due to tide, sea level rise (SLR) and climatic variability (change). However, the quantitative representation of how the energy budget and groundwater variation of coastal wetlands respond to frequent water level fluctuation is limited, especially at regional scales. This study developed a physically based distributed wetland hydrological model by integrating coastal processes and considering the inundation influence on energy budget and ET. Analysis using in situ measurements and satellite data for a coastal wetland in North Carolina confirm that the model sufficiently captures the wetland hydrologic behaviors. The validated model was then applied to examine the wetland hydrodynamics under a 30-year historical climate forcing (1985-2014) for the wetland region. The simulation reveals that 43% of the study area has inundation events, 63% of which has a frequency higher than 50% each year. The canopy evaporation and transpiration decline dramatically when the inundation level exceeds the canopy height. Additionally, inundation causes about 10% increase of the net shortwave radiation. This study also demonstrates that the critical wetland zones highly influenced by the coastal processes spans 300-800 m from the coastline. The model developed in the study offers a new tool for understanding the complex wetland hydrodynamics in response to natural and human-induced disturbances at landscape to regional scales.

A catalog of Louisiana's nesting seabird colonies

Science.gov (United States)

Fontenot, William R.; Cardiff, Steve W.; DeMay, Richard A.; Dittmann, Donna L.; Hartley, Stephen B.; Jeske, Clinton W.; Lorenz, Nicole; Michot, Thomas C.; Purrington, Robert Dan; Seymour, Michael; Vermillion, William G.

2012-01-01

Summarizing his colonial nesting waterbird survey experiences along the northern coast of the Gulf of Mexico in a paper presented to the Colonial Waterbird Group of the Waterbird Society (Portnoy 1978), bird biologist John W. Portnoy stated, “This huge concentration of nesting waterbirds, restricted almost entirely to the wetlands and estuaries of southern Louisiana, is unmatched in all of North America; for example, a 1975 inventory of wading birds along the Atlantic Coast from Maine to Florida [Custer and Osborn, in press], tallied 250,000 breeding [waterbirds] of 14 species, in contrast with the 650,000 birds of 15 species just from Sabine Pass to Mobile Bay.” The “650,000 birds” to which Portnoy referred, were tallied by him in a 1976 survey of coastal Louisiana, Mississippi, and Alabama (see below, under “Major Surveys” section). According to the National Atlas of Coastal Waterbird Colonies in the Contiguous United States: 1976-82 (Spendelow and Patton 1988), the percentages of the total U.S. populations of Laughing Gull (11%), Forster's Tern (52%), Royal Tern (16%), Sandwich Tern (77%), and Black Skimmer (44%) which annually nest in Louisiana are significant – perhaps crucially so in the cases of Forster's Tern, Sandwich Tern, and Black Skimmer. Nearly three decades after Spendelow and Patton's determinations above, coastal Louisiana still stands out as the major center of colonial wading bird and seabird nesting in all of the United States. Within those three intervening decades, however, the

LAND COVER - CLASSIFICATION and Other Data from FIXED PLATFORM From Coastal Waters of Gulf of Mexico from 19880101 to 19891231 (NODC Accession 9100034)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Wetland Assessment Data was collected from Coastal waters of Gulf of Mexico by Louisiana State and the Louisiana Geological Service under MMS Cooperative Agreement...

Macroclimatic change expected to transform coastal wetland ecosystems this century

Science.gov (United States)

Gabler, Christopher A.; Osland, Michael J.; Grace, James B.; Stagg, Camille L.; Day, Richard H.; Hartley, Stephen B.; Enwright, Nicholas M.; From, Andrew S.; McCoy, Meagan L.; McLeod, Jennie L.

2017-01-01

Coastal wetlands, existing at the interface between land and sea, are highly vulnerable to climate change. Macroclimate (for example, temperature and precipitation regimes) greatly influences coastal wetland ecosystem structure and function. However, research on climate change impacts in coastal wetlands has concentrated primarily on sea-level rise and largely ignored macroclimatic drivers, despite their power to transform plant community structure and modify ecosystem goods and services. Here, we model wetland plant community structure based on macroclimate using field data collected across broad temperature and precipitation gradients along the northern Gulf of Mexico coast. Our analyses quantify strongly nonlinear temperature thresholds regulating the potential for marsh-to-mangrove conversion. We also identify precipitation thresholds for dominance by various functional groups, including succulent plants and unvegetated mudflats. Macroclimate-driven shifts in foundation plant species abundance will have large effects on certain ecosystem goods and services. Based on current and projected climatic conditions, we project that transformative ecological changes are probable throughout the region this century, even under conservative climate scenarios. Coastal wetland ecosystems are functionally similar worldwide, so changes in this region are indicative of potential future changes in climatically similar regions globally.

Functional roles of wetlands: a case study of the coastal wetlands of ...

African Journals Online (AJOL)

The Coastal Wetland of the study area is used extensively for a large number of activities. It is also threatened because of their vulnerability and attractiveness for development. These therefore prompted a study of the Wetlands for a period of 18 months (July 1997 – December 1998) to identify the functional roles that ...

Wildlife resources of coastal wetlands of Lagos state | Jenyo-Oni ...

African Journals Online (AJOL)

Almost 35% of all rare and endangered animal species are either located in wetland areas or are dependent on them. Coastal wetlands are extremely important to coastal states such as the study area and are extensively exploited. This study gives an inventory of the wildlife resources of the study area and its utilization.

Fringe benefit: Value of restoring coastal wetlands for Great Lakes fisheries

Science.gov (United States)

Fishery support is recognized as a valuable ecosystem service provided by Great Lakes coastal wetlands, but it is challenging to quantify because multiple species and habitats are involved. Recent studies indicate that coastal wetland area is proportional to fishery harvest among...

Resilience of coastal wetlands to extreme hydrologicevents in Apalachicola Bay

Science.gov (United States)

Medeiros, S. C.; Singh, A.; Tahsin, S.

2017-12-01

Extreme hydrologic events such as hurricanes and droughts continuously threaten wetlands which provide key ecosystem services in coastal areas. The recovery time for vegetation after impact fromthese extreme events can be highly variable depending on the hazard type and intensity. Apalachicola Bay in Florida is home to a rich variety of saltwater and freshwater wetlands and is subject to a wide rangeof hydrologic hazards. Using spatiotemporal changes in Landsat-based empirical vegetation indices, we investigate the impact of hurricane and drought on both freshwater and saltwater wetlands from year 2000to 2015 in Apalachicola Bay. Our results indicate that saltwater wetlands are more resilient than freshwater wetlands and suggest that in response to hurricanes, the coastal wetlands took almost a year to recover,while recovery following a drought period was observed after only a month.

Integrated conceptual ecological model and habitat indices for the southwest Florida coastal wetlands

Science.gov (United States)

Wingard, G. Lynn; Lorenz, J. L.

2014-01-01

The coastal wetlands of southwest Florida that extend from Charlotte Harbor south to Cape Sable, contain more than 60,000 ha of mangroves and 22,177 ha of salt marsh. These coastal wetlands form a transition zone between the freshwater and marine environments of the South Florida Coastal Marine Ecosystem (SFCME). The coastal wetlands provide diverse ecosystem services that are valued by society and thus are important to the economy of the state. Species from throughout the region spend part of their life cycle in the coastal wetlands, including many marine and coastal-dependent species, making this zone critical to the ecosystem health of the Everglades and the SFCME. However, the coastal wetlands are increasingly vulnerable due to rising sea level, changes in storm intensity and frequency, land use, and water management practices. They are at the boundary of the region covered by the Comprehensive Everglades Restoration Plan (CERP), and thus are impacted by both CERP and marine resource management decisions. An integrated conceptual ecological model (ICEM) for the southwest coastal wetlands of Florida was developed that illustrates the linkages between drivers, pressures, ecological process, and ecosystem services. Five ecological indicators are presented: (1) mangrove community structure and spatial extent; (2) waterbirds; (3) prey-base fish and macroinvertebrates; (4) crocodilians; and (5) periphyton. Most of these indicators are already used in other areas of south Florida and the SFCME, and therefore will allow metrics from the coastal wetlands to be used in system-wide assessments that incorporate the entire Greater Everglades Ecosystem.

Assessing the recovery of coastal wetlands from oil spills

International Nuclear Information System (INIS)

Mendelssohn, I.A.; Hester, M.W.; Hill, J.M.

1993-01-01

The impact of oil spills on coastal environments and the ability of these systems to exhibit long-term recovery has received increased attention in recent years. Although oil spills can have significant short-term impacts on coastal marshes, the long-term effects and eventual recovery are not well documented. Estuarine marshes have sometimes been reported to exhibit slow recovery after oil spills, whereas in other instances they appear to have great resiliency, with complete recovery after one or two years. To document and understand this phenomenon better, we have investigated the long-term recovery of a south Louisiana estuarine marsh exposed to an accidental spill of crude oil. Although a pipeline rupture releasing Louisiana crude oil caused the near complete mortality of a brackish marsh dominated by Spartina patens and S. alterniflora, this marsh completely recovered four years after the spill with no differences in plant species cover between oiled and reference marshes. Remotely sensed imagery of the study site confirmed the relatively rapid recovery demonstrated by the ground truth data. Louisiana's coastal marshes are naturally experiencing rapid rates of deterioration. Land loss rates, determined from aerial imagery, at the spill site and adjacent reference areas before and after the spill demonstrated that the long-term loss rates were not affected by the spill event

Predictive occurrence models for coastal wetland plant communities: delineating hydrologic response surfaces with multinomial logistic regression

Science.gov (United States)

Snedden, Gregg A.; Steyer, Gregory D.

2013-01-01

Understanding plant community zonation along estuarine stress gradients is critical for effective conservation and restoration of coastal wetland ecosystems. We related the presence of plant community types to estuarine hydrology at 173 sites across coastal Louisiana. Percent relative cover by species was assessed at each site near the end of the growing season in 2008, and hourly water level and salinity were recorded at each site Oct 2007–Sep 2008. Nine plant community types were delineated with k-means clustering, and indicator species were identified for each of the community types with indicator species analysis. An inverse relation between salinity and species diversity was observed. Canonical correspondence analysis (CCA) effectively segregated the sites across ordination space by community type, and indicated that salinity and tidal amplitude were both important drivers of vegetation composition. Multinomial logistic regression (MLR) and Akaike's Information Criterion (AIC) were used to predict the probability of occurrence of the nine vegetation communities as a function of salinity and tidal amplitude, and probability surfaces obtained from the MLR model corroborated the CCA results. The weighted kappa statistic, calculated from the confusion matrix of predicted versus actual community types, was 0.7 and indicated good agreement between observed community types and model predictions. Our results suggest that models based on a few key hydrologic variables can be valuable tools for predicting vegetation community development when restoring and managing coastal wetlands.

[Vulnerability assessment on the coastal wetlands in the Yangtze Estuary under sea-level rise].

Science.gov (United States)

Cui, Li-Fang; Wang, Ning; Ge, Zhen-Ming; Zhang, Li-Quan

2014-02-01

To study the response of coastal wetlands to climate change, assess the impacts of climate change on the coastal wetlands and formulate feasible and practical mitigation strategies are the important prerequisite for securing coastal ecosystems. In this paper, the possible impacts of sea level rise caused by climate change on the coastal wetlands in the Yangtze Estuary were analyzed by the Source-Pathway-Receptor-Consequence (SPRC) model and IPCC definition on the vulnerability. An indicator system for vulnerability assessment was established, in which sea-level rise rate, subsidence rate, habitat elevation, inundation threshold of habitat and sedimentation rate were selected as the key indicators. A quantitatively spatial assessment method based on the GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability index for the assessment of coastal wetlands in the Yangtze Estuary under the scenarios of sea-level rise. The vulnerability assessments on the coastal wetlands in the Yangtze Estuary in 2030 and 2050 were performed under two sea-level rise scenarios (the present sea-level rise trend over recent 30 years and IPCC A1F1 scenario). The results showed that with the projection in 2030 under the present trend of sea-level rise (0.26 cm x a(-1)), 6.6% and 0.1% of the coastal wetlands were in the low and moderate vulnerabilities, respectively; and in 2050, 9.8% and 0.2% of the coastal wetlands were in low and moderate vulnerabilities, respectively. With the projection in 2030 under the A1F1 scenario (0.59 cm x a(-1)), 9.0% and 0.1% of the coastal wetlands were in the low and moderate vulnerabilities, respectively; and in 2050, 9.5%, 1.0% and 0.3% of the coastal wetlands were in the low, moderate and high vulnerabilities, respectively.

Louisiana Barrier Island Comprehensive Monitoring (BICM) Program Summary Report: Data and Analyses 2006 through 2010

Science.gov (United States)

Kindinger, Jack G.; Buster, Noreen A.; Flocks, James G.; Bernier, Julie C.; Kulp, Mark A.

2013-01-01

The Barrier Island Comprehensive Monitoring (BICM) program was implemented under the Louisiana Coastal Area Science and Technology (LCA S&T) office as a component of the System Wide Assessment and Monitoring (SWAMP) program. The BICM project was developed by the State of Louisiana (Coastal Protection Restoration Authority [CPRA], formerly Department of Natural Resources [DNR]) to complement other Louisiana coastal monitoring programs such as the Coastwide Reference Monitoring System-Wetlands (CRMS-Wetlands) and was a collaborative research effort by CPRA, University of New Orleans (UNO), and the U.S. Geological Survey (USGS). The goal of the BICM program was to provide long-term data on the barrier islands of Louisiana that could be used to plan, design, evaluate, and maintain current and future barrier-island restoration projects. The BICM program used both historical and newly acquired (2006 to 2010) data to assess and monitor changes in the aerial and subaqueous extent of islands, habitat types, sediment texture and geotechnical properties, environmental processes, and vegetation composition. BICM datasets included aerial still and video photography (multiple time series) for shoreline positions, habitat mapping, and land loss; light detection and ranging (lidar) surveys for topographic elevations; single-beam and swath bathymetry; and sediment grab samples. Products produced using BICM data and analyses included (but were not limited to) storm-impact assessments, rate of shoreline and bathymetric change, shoreline-erosion and accretion maps, high-resolution elevation maps, coastal-shoreline and barrier-island habitat-classification maps, and coastal surficial-sediment characterization maps. Discussions in this report summarize the extensive data-collection efforts and present brief interpretive analyses for four coastal Louisiana geographic regions. In addition, several coastal-wide and topical themes were selected that integrate the data and analyses within a

Assessment on vulnerability of coastal wetlands to sea level rise in the Yangtze Estuary, China

Science.gov (United States)

Cui, L.; Ge, Z.; Zhang, L.

2013-12-01

The Yangtze Delta in China is vital economic hubs in terms of settlement, industry, agriculture, trade and tourism as well as of great environmental significance. In recent decades, the prospect of climate change, in particular sea level rise and its effects on low lying coastal areas have generated worldwide attention to coastal ecosystems. Coastal wetlands, as important parts of coastal ecosystem, are particularly sensitive to sea level rise. To study the responses of coastal wetlands to climate change, assess the impacts of climate change on coastal wetlands and formulate feasible and practical mitigation strategies are the important prerequisites for securing the coastal zone ecosystems. In this study, taking the coastal wetlands in the Yangtze Estuary as a case study, the potential impacts of sea-level rise to coastal wetlands habitat were analyzed by the Source-Pathway-Receptor-Consequence (SPRC) model. The key indicators, such as the sea-level rise rate, subsidence rate, elevation, daily inundation duration of habitat and sedimentation rate, were selected to build a vulnerability assessment system according to the IPCC definition of vulnerability, i.e. the aspects of exposure, sensitivity and adaptation. A quantitatively spatial assessment method on the GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability. The vulnerability assessment on the coastal wetlands in the Yangtze Estuary under the sea level rise rate of the present trend and IPCC A1F1 scenario were performed for three sets of projections of short-term (2030s), mid-term (2050s) and long-term (2100s). The results showed that at the present trend of sea level rise rate of 0.26 cm/a, 92.3 % of the coastal wetlands in the Yangtze Estuary was in the EVI score of 0 in 2030s, i.e. the impact of sea level rise on habitats/species of coastal wetlands was negligible. While 7.4 % and 0.3 % of the coastal wetlands were in the EVI score of

Integrated analysis of PALSAR/Radarsat-1 InSAR and ENVISAT altimeter data for mapping of absolute water level changes in Louisiana wetlands

Science.gov (United States)

Kim, J.-W.; Lu, Z.; Lee, H.; Shum, C.K.; Swarzenski, C.M.; Doyle, T.W.; Baek, S.-H.

2009-01-01

Interferometric Synthetic Aperture Radar (InSAR) has been used to detect relative water level changes in wetlands. We developed an innovative method to integrate InSAR and satellite radar altimetry for measuring absolute or geocentric water level changes and applied the methodology to remote areas of swamp forest in coastal Louisiana. Coherence analysis of InSAR pairs suggested that the HH polarization is preferred for this type of observation, and polarimetric analysis can help to identify double-bounce backscattering areas in the wetland. ENVISAT radar altimeter-measured 18-Hz (along-track sampling of 417 m) water level data processed with regional stackfile method have been used to provide vertical references for water bodies separated by levees. The high-resolution (~ 40 m) relative water changes measured from ALOS PALSAR L-band and Radarsat-1 C-band InSAR are then integrated with ENVISAT radar altimetry to obtain absolute water level. The resulting water level time series were validated with in situ gauge observations within the swamp forest. We anticipate that this new technique will allow retrospective reconstruction and concurrent monitoring of water conditions and flow dynamics in wetlands, especially those lacking gauge networks.

Coastal wetlands, sea level, and the dimensions of geomorphic resilience

Science.gov (United States)

Phillips, Jonathan D.

2018-03-01

Geomorphic system resilience is often perceived as an intrinsic property of system structure and interactions but is also related to idiosyncratic place and history factors. The importance of geographical and historical circumstances makes it difficult to generate categorical statements about geomorphic resilience. However, network-based analyses of system structure can be used to determine the dynamical stability (= resilience) based on generally applicable relationships and to determine scenarios of stability or instability. These provide guidelines for assessing place and history factors to assess resilience. A model of coastal wetlands is analyzed, based on interactions among relative sea level, wetland surface elevation, hydroperiod, vegetation, and sedimentation. The system is generally (but not always) dynamically unstable and non-resilient. Because of gradients of environmental factors and patchy distributions of microtopography and vegetation, a coastal wetland landscape may have extensive local variations in stability/resilience and in the key relationships that trigger instabilities. This is illustrated by a case study where dynamically unstable fragmentation is found in two nearby coastal wetlands in North Carolina's Neuse River estuary-Otter Creek Mouth and Anderson Creek. Neither is keeping pace with relative sea level rise, and both show unstable state transitions within the wetland system; but locally stable relationships exist within the wetland systems.

Biodiversity studies in three Coastal Wetlands in Ghana, West Africa ...

African Journals Online (AJOL)

Plant biodiversity studies of three coastal wetlands in Ghana were made. The wetlands are the Sakumo, Muni-Pomadze and Densu Delta Ramsar sites. Each wetland is made up of a flood plain which consists of salt marsh (about 20%), mangrove swamps (between 15 and 30%), fresh water swamp (about 40 - 45%), and in ...

Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Mississippi: WETLANDS (Wetland Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing coastal wetlands classified according to the Environmental Sensitivity Index (ESI) classification system for...

Changes of hydrological environment and their influences on coastal wetlands in the southern Laizhou Bay, China.

Science.gov (United States)

Zhang, Xuliang; Zhang, Yuanzhi; Sun, Hongxia; Xia, Dongxing

2006-08-01

The structure and function of the coastal wetland ecosystem in the southern Laizhou Bay have been changed greatly and influenced by regional hydrological changes. The coastal wetlands have degraded significantly during the latest 30 years due to successive drought, decreasing of runoff, pollution, underground saline water intrusion, and aggravating marine disasters such as storm tides and sea level rising. Most archaic lakes have vanished, while artificial wetlands have been extending since natural coastal wetlands replaced by salt areas and ponds of shrimps and crabs. The pollution of sediments in inter-tidal wetlands and the pollution of water quality in sub-tidal wetlands are getting worse and therefore "red tides" happen more often than before. The biodiversity in the study area has been decreased. Further studies are still needed to protect the degraded coastal wetlands in the area.

Carbon Sequestration in Wetland Soils of the Northern Gulf of Mexico Coastal Region

Science.gov (United States)

Coastal wetlands play an important but complex role in the global carbon cycle, contributing to the ecosystem service of greenhouse gas regulation through carbon sequestration. Although coastal wetlands occupy a small percent of the total US land area, their potential for carbon...

Analysis of Unmanned Aerial Vehicle (UAV) hyperspectral remote sensing monitoring key technology in coastal wetland

Science.gov (United States)

Ma, Yi; Zhang, Jie; Zhang, Jingyu

2016-01-01

The coastal wetland, a transitional zone between terrestrial ecosystems and marine ecosystems, is the type of great value to ecosystem services. For the recent 3 decades, area of the coastal wetland is decreasing and the ecological function is gradually degraded with the rapid development of economy, which restricts the sustainable development of economy and society in the coastal areas of China in turn. It is a major demand of the national reality to carry out the monitoring of coastal wetlands, to master the distribution and dynamic change. UAV, namely unmanned aerial vehicle, is a new platform for remote sensing. Compared with the traditional satellite and manned aerial remote sensing, it has the advantage of flexible implementation, no cloud cover, strong initiative and low cost. Image-spectrum merging is one character of high spectral remote sensing. At the same time of imaging, the spectral curve of each pixel is obtained, which is suitable for quantitative remote sensing, fine classification and target detection. Aimed at the frontier and hotspot of remote sensing monitoring technology, and faced the demand of the coastal wetland monitoring, this paper used UAV and the new remote sensor of high spectral imaging instrument to carry out the analysis of the key technologies of monitoring coastal wetlands by UAV on the basis of the current situation in overseas and domestic and the analysis of developing trend. According to the characteristic of airborne hyperspectral data on UAV, that is "three high and one many", the key technology research that should develop are promoted as follows: 1) the atmosphere correction of the UAV hyperspectral in coastal wetlands under the circumstance of complex underlying surface and variable geometry, 2) the best observation scale and scale transformation method of the UAV platform while monitoring the coastal wetland features, 3) the classification and detection method of typical features with high precision from multi scale

Beyond just sea-level rise: Considering macroclimatic drivers within coastal wetland vulnerability assessments to climate change

Science.gov (United States)

Osland, Michael J.; Enwright, Nicholas M.; Day, Richard H.; Gabler, Christopher A.; Stagg, Camille L.; Grace, James B.

2016-01-01

Due to their position at the land-sea interface, coastal wetlands are vulnerable to many aspects of climate change. However, climate change vulnerability assessments for coastal wetlands generally focus solely on sea-level rise without considering the effects of other facets of climate change. Across the globe and in all ecosystems, macroclimatic drivers (e.g., temperature and rainfall regimes) greatly influence ecosystem structure and function. Macroclimatic drivers have been the focus of climate-change related threat evaluations for terrestrial ecosystems, but largely ignored for coastal wetlands. In some coastal wetlands, changing macroclimatic conditions are expected to result in foundation plant species replacement, which would affect the supply of certain ecosystem goods and services and could affect ecosystem resilience. As examples, we highlight several ecological transition zones where small changes in macroclimatic conditions would result in comparatively large changes in coastal wetland ecosystem structure and function. Our intent in this communication is not to minimize the importance of sea-level rise. Rather, our overarching aim is to illustrate the need to also consider macroclimatic drivers within vulnerability assessments for coastal wetlands.

Breeding biology of Mottled Ducks on agricultural lands in southwestern Louisiana

Science.gov (United States)

Durham, R.S.; Afton, A.D.

2006-01-01

Breeding biology of Anas fulvigula maculosa (Mottled Ducks) has been described in coastal marsh and associated habitats, but little information is available for agricultural habitats in Louisiana. We located nests to determine nest-initiation dates and clutch sizes during the primary breeding season (February-May) in 1999 (n = 29) and 2000 (n = 37) on agricultural lands in southwestern Louisiana. In 1999, 60% of located nests were initiated between 22 March and 10 April, whereas in 2000, only 22% of nests were initiated during the same time period. Average clutch size was 0.9 eggs smaller in 2000 than in 1999. Annual differences in reproductive parameters corresponded with extremely dry conditions caused by low rainfall before the laying period in 2000. Flooded rice fields appear to be important loafing and feeding habitat of Mottled Ducks nesting in agricultural lands, especially during drought periods when other wetland types are not available or where natural wetlands have been eliminated.

Louisiana's 2017 Master Plan for a Sustainable Coast

Science.gov (United States)

Haase, B.

2017-12-01

The Coastal Protection and Restoration Authority is charged with coordinating restoration and protection investments through the development and implementation of Louisiana's Comprehensive Master Plan for a Sustainable Coast. The first master plan was submitted to the Louisiana Legislature in 2007 and is mandated to be updated every five years. The plan's objectives are to reduce economic losses from flooding, promote sustainability by harnessing natural processes, provide habitats for commercial and recreational activities, sustain cultural heritage and promote a viable working coast. Two goals drive decision making about the appropriate suite of restoration and protection projects to include in the Plan: restore and maintain Louisiana's wetlands and provide flood protection for coastal Louisiana's citizens. As part of the decision making process, a wide range of additional metrics are used to evaluate the complex, competing needs of communities, industries, navigation and fisheries. The master plan decision making process includes the identification of individual protection and restoration projects that are evaluated with landscape, storm surge, and risk assessment models and then ranked by how well they perform over time across the set of decision drivers and metrics. High performing projects are assembled into alternatives constrained by available funding and river resources. The planning process is grounded not only on extensive scientific analysis but also on interdisciplinary collaboration between scientists, engineers, planners, community advocates, and coastal stakeholders which creates the long-term dialogue needed for complex environmental planning decisions. It is through this collaboration that recommended alternatives are reviewed and modified to develop the final Plan. Keywords:alternative formulation, comprehensive planning, ecosystem restoration, flood risk reduction and stakeholder engagement

A global standard for monitoring coastal wetland vulnerability to accelerated sea-level rise

Science.gov (United States)

Webb, Edward L.; Friess, Daniel A.; Krauss, Ken W.; Cahoon, Donald R.; Guntenspergen, Glenn R.; Phelps, Jacob

2013-01-01

Sea-level rise threatens coastal salt-marshes and mangrove forests around the world, and a key determinant of coastal wetland vulnerability is whether its surface elevation can keep pace with rising sea level. Globally, a large data gap exists because wetland surface and shallow subsurface processes remain unaccounted for by traditional vulnerability assessments using tide gauges. Moreover, those processes vary substantially across wetlands, so modelling platforms require relevant local data. The low-cost, simple, high-precision rod surface-elevation table–marker horizon (RSET-MH) method fills this critical data gap, can be paired with spatial data sets and modelling and is financially and technically accessible to every country with coastal wetlands. Yet, RSET deployment has been limited to a few regions and purposes. A coordinated expansion of monitoring efforts, including development of regional networks that could support data sharing and collaboration, is crucial to adequately inform coastal climate change adaptation policy at several scales.

Nitrogen source tracking with δ15N content of coastal wetland plants in Hawaii

Science.gov (United States)

Gregory L. Bruland; Richard A.. Mackenzie

2010-01-01

Inter- and intra-site comparisons of the nitrogen (N) stable isotope composition of wetland plant species have been used to identify sources of N in coastal areas. In this study, we compared δ15N values from different herbaceous wetland plants across 34 different coastal wetlands from the five main Hawaiian Islands and investigated relationships of δ15N with...

Beyond just sea-level rise: considering macroclimatic drivers within coastal wetland vulnerability assessments to climate change.

Science.gov (United States)

Osland, Michael J; Enwright, Nicholas M; Day, Richard H; Gabler, Christopher A; Stagg, Camille L; Grace, James B

2016-01-01

Due to their position at the land-sea interface, coastal wetlands are vulnerable to many aspects of climate change. However, climate change vulnerability assessments for coastal wetlands generally focus solely on sea-level rise without considering the effects of other facets of climate change. Across the globe and in all ecosystems, macroclimatic drivers (e.g., temperature and rainfall regimes) greatly influence ecosystem structure and function. Macroclimatic drivers have been the focus of climate change-related threat evaluations for terrestrial ecosystems, but largely ignored for coastal wetlands. In some coastal wetlands, changing macroclimatic conditions are expected to result in foundation plant species replacement, which would affect the supply of certain ecosystem goods and services and could affect ecosystem resilience. As examples, we highlight several ecological transition zones where small changes in macroclimatic conditions would result in comparatively large changes in coastal wetland ecosystem structure and function. Our intent in this communication is not to minimize the importance of sea-level rise. Rather, our overarching aim is to illustrate the need to also consider macroclimatic drivers within vulnerability assessments for coastal wetlands. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Coastal Wetland Ecosystem Responses to Climate Change: the Role of Macroclimatic Drivers along the Northern Gulf of Mexico

Science.gov (United States)

Osland, M. J.; Enwright, N.; Day, R. H.; Gabler, C. A.; Stagg, C. L.; From, A. S.

2014-12-01

Across the globe, macroclimatic drivers greatly influence coastal wetland ecosystem structure and function. However, changing macroclimatic conditions are rarely incorporated into coastal wetland vulnerability assessments. Here, we quantify the influence of macroclimatic drivers upon coastal wetland ecosystems along the Northern Gulf of Mexico (NGOM) coast. From a global perspective, the NGOM coast provides several excellent opportunities to examine the effects of climate change upon coastal wetlands. The abundant coastal wetland ecosystems in the region span two major climatic gradients: (1) a winter temperature gradient that crosses temperate to tropical climatic zones; and (2) a precipitation gradient that crosses humid to semi-arid zones. We present analyses where we used geospatial data (historical climate, hydrology, and coastal wetland coverage) and field data (soil, elevation, and plant community composition and structure) to quantify climate-mediated ecological transitions. We identified winter climate and precipitation-based thresholds that separate mangrove forests from salt marshes and vegetated wetlands from unvegetated wetlands, respectively. We used simple distribution and abundance models to evaluate the potential ecological effects of alternative future climate change scenarios. Our results illustrate and quantify the importance of macroclimatic drivers and indicate that climate change could result in landscape-scale changes in coastal wetland ecosystem structure and function. These macroclimate-mediated ecological changes could affect the supply of some ecosystem goods and services as well as the resilience of these ecosystems to stressors, including accelerated sea level rise. Collectively, our findings highlight the importance of incorporating macroclimatic drivers within future-focused coastal wetland vulnerability assessments.

Dynamics of carbon sequestration in a coastal wetland using radiocarbon measurements

Science.gov (United States)

Choi, Yonghoon; Wang, Yang

2004-12-01

Coastal wetlands are sensitive to global climate change and may play an important role in the global carbon cycle. However, the dynamics of carbon (C) cycling in coastal wetlands and its response to sea level change associated with global warming is still poorly understood. In this study, we estimated the long-term and short-term rates of C accumulation, using C and C isotopic measurements of peat cores collected along a soil chronosequence, in a coastal wetland in north Florida. The long-term C accumulation rates determined by examining the C inventory and the radioactive decay of radiocarbon as a function of depth in the peat cores decrease with time from ˜130 ± 9 g C/m2/yr over the last century to ˜13 ± 2 g C/m2/yr over the millennium timescale. The short-term C accumulation rates estimated by examining the differences in the radiocarbon and C contents of the surfacial peat between archived (1985, 1988) and present (1996 and 1997) samples range from 42 to 193 g C/m2/yr in low marsh, from 18 to 184 g C/m2/yr in middle marsh, and from -50 to 181 g C/m2/yr in high marsh. The high end-values of our estimated short-term C accumulation rates are comparable to the estimated rates of C sequestration in coastal wetlands reported by [2003], but are significantly higher than our estimated long-term rates in the marshes and are also much higher than the published rates of C sequestration in northern peatlands. The higher recent rates of C accumulation in coastal marshes, in comparison with the longer-term rates, are due to slow but continuous decomposition of organic matter in the peat over time. However, other factors such as increased primary production in the coastal wetland over the last decades or century, due to a rise in mean sea level and/or CO2 and nitrogen fertilization effect, could also have contributed to the large difference between the recent and longer-term rates. Our data indicate that salt marshes in this area have been and continue to be a sink for

Fertilizer legacies meet saltwater incursion: challenges and constraints for coastal plain wetland restoration

Directory of Open Access Journals (Sweden)

Marcelo Ardón

2017-07-01

Full Text Available Coastal wetland restoration is an important tool for climate change adaptation and excess nutrient runoff mitigation. However, the capacity of restored coastal wetlands to provide multiple ecosystem services is limited by stressors, such as excess nutrients from upstream agricultural fields, high nutrient legacies on-site, and rising salinities downstream. The effects of these stressors are exacerbated by an accelerating hydrologic cycle, expected to cause longer droughts punctuated by more severe storms. We used seven years of surface water and six years of soil solution water chemistry from a large (440 ha restored wetland to examine how fertilizer legacy, changes in hydrology, and drought-induced salinization affect dissolved nutrient and carbon concentrations. To better understand the recovery trajectory of the restored wetland, we also sampled an active agricultural field and two mature forested wetlands. Our results show that nitrogen (N and phosphorus (P concentrations in soil solution were 2–10 times higher in the restored wetland compared to two mature forested wetlands, presumably due to legacy fertilizer mobilized by reflooding. Despite elevated nutrient concentrations relative to reference wetlands, the restored wetland consistently attenuated N and P pulses delivered from an upstream farm. Even with continued loading, N and P concentrations in surface water throughout the restored wetland have decreased since the initial flooding. Our results suggest that high nutrient concentrations and export from wetlands restored on agricultural lands may be a severe but temporary problem. If field to wetland conversion is to become a more widespread method for ameliorating nutrient runoff and adapting coastal plain ecosystems to climate change, we should adopt new methods for minimizing the initial export phase of wetland restoration efforts.

Anaerobic ammonium oxidation and its contribution to nitrogen removal in China’s coastal wetlands

Science.gov (United States)

Hou, Lijun; Zheng, Yanling; Liu, Min; Li, Xiaofei; Lin, Xianbiao; Yin, Guoyu; Gao, Juan; Deng, Fengyu; Chen, Fei; Jiang, Xiaofen

2015-01-01

Over the past several decades, human activities have caused substantial enrichment of reactive nitrogen in China’s coastal wetlands. Although anaerobic ammonium oxidation (anammox), the process of oxidizing ammonium into dinitrogen gas through the reduction of nitrite, is identified as an important process for removing reactive nitrogen, little is known about the dynamics of anammox and its contribution to nitrogen removal in nitrogen-enriched environments. Here, we examine potential rates of anammox and associate them with bacterial diversity and abundance across the coastal wetlands of China using molecular and isotope tracing techniques. High anammox bacterial diversity was detected in China’s coastal wetlands and included Candidatus Scalindua, Kuenenia, Brocadia, and Jettenia. Potential anammox rates were more closely associated with the abundance of anammox bacteria than to their diversity. Among all measured environmental variables, temperature was a key environmental factor, causing a latitudinal distribution of the anammox bacterial community composition, biodiversity and activity along the coastal wetlands of China. Based on nitrogen isotope tracing experiments, anammox was estimated to account for approximately 3.8–10.7% of the total reactive nitrogen removal in the study area. Combined with denitrification, anammox can remove 20.7% of the total external terrigenous inorganic nitrogen annually transported into China’s coastal wetland ecosystems. PMID:26494435

Tracking sedimentation from the historic A.D. 2011 Mississippi River flood in the deltaic wetlands of Louisiana, USA

Science.gov (United States)

Khan, Nicole S.; Horton, Benjamin P.; McKee, Karen L.; Jerolmack, Douglas; Falcini, Federico; Enache, Mihaela D.; Vane, Christopher H.

2013-01-01

Management and restoration of the Mississippi River deltaic plain (southern United States) and associated wetlands require a quantitative understanding of sediment delivery during large flood events, past and present. Here, we investigate the sedimentary fingerprint of the 2011 Mississippi River flood across the Louisiana coast (Atchafalaya Delta, Terrebonne, Barataria, and Mississippi River Delta basins) to assess spatial patterns of sedimentation and to identify key indicators of sediment provenance. The sediment deposited in wetlands during the 2011 flood was distinguished from earlier deposits based on biological characteristics, primarily absence of plant roots and increased presence of centric (planktonic) diatoms indicative of riverine origin. By comparison, the lithological (bulk density, organic matter content, and grain size) and chemical (stable carbon isotopes of bulk organic matter) properties of flood sediments were nearly identical to the underlying deposit. Flood sediment deposition was greatest in wetlands near the Atchafalaya and Mississippi Rivers and accounted for a substantial portion (37% to 85%) of the annual accretion measured at nearby monitoring stations. The amount of sediment delivered to those basins (1.1–1.6 g cm−2) was comparable to that reported previously for hurricane sedimentation along the Louisiana coast (0.8–2.1 g cm−2). Our findings not only provide insight into how large-scale river floods influence wetland sedimentation, they lay the groundwork for identifying previous flood events in the stratigraphic record.

Local and regional scale exchanges of dissolved organic carbon (DOC) between tidal wetlands and their adjacent coastal waters

Science.gov (United States)

Osburn, C. L.; Joshi, I.; Lebrasse, M. C.; Oviedo-Vargas, D.; Bianchi, T. S.; Bohnenstiehl, D. R.; D'Sa, E. J.; He, R.; Ko, D.; Arellano, A.; Ward, N. D.

2017-12-01

The contribution of blue carbon from tidal wetlands to the coastal ocean in the form of dissolved organic carbon (DOC) represents a terrestrial-aquatic linkage of increasing importance. DOC flux results will be presented from local (tidal creek) and regional (bays) scale studies in which various combinations of field observations, ocean-color satellite observations, and the outputs of high-resolution hydrodynamic models were used to estimate DOC export. The first project was located in Bald Head Creek, a tributary to the Cape Fear River estuary in eastern North Carolina (NC). DOC fluxes were computed using a bathymetric data collected via unmanned surface vehicle (USV) and a numerical hydrodynamic model (SCHISM) based on the relationships between colored dissolved organic matter (CDOM) absorption, DOC concentration, and salinity taken from field observations. Model predictions estimated an annual net export of DOC at 54 g C m-2 yr-1 from the tidal creek to the adjacent estuary. Carbon stable isotope (δ13C) values were used to estimate the contribution of wetland carbon to this export. In the second project, DOC fluxes from the Apalachicola Bay, FL, Barataria Bay, LA, were based on the development of algorithms between DOC and CDOM absorption derived from the VIIRS ocean color sensor. The Navy Coastal Ocean Model (NCOM) was used to compute salt flux estimates from each bay to the Louisiana-Texas shelf. The relationship between salinity and CDOM was used to estimate net annual DOC exports of 8.35 x 106 g C m-2 y-1 (Apalachicola Bay) and 7.14 x 106 g C m-2 yr-1 (Barataria Bay). These values approximate 13% and 9% of the annual loads of DOC from the Mississippi River to the Gulf of Mexico, respectively. CDOM and lignin were used in a mixing model to estimate wetland-derived DOC were 2% for Apalachicola Bay and 13% for Barataria Bay, the latter having one of the highest rates of relative sea level rise in North America. Results from our project demonstrated the utility

Application of Long Distance Conveyance (LDC) of Dredged Sediments to Louisiana Coastal Restoration

Science.gov (United States)

2011-01-01

generally use some type of bucket for digging the sediment, then hoist or boom the load to the surface. Most common hydraulic methods use a centrifugal...sediment. The loaded bucket is hoisted to the surface and side dumped into a transportation unit, or into the disposal site. Transportation units are...Conveyance (LDC) of Dredged Sediments to Louisiana Coastal Restoration Timothy Welp Coastal and Hydraulics Laboratory U.S. Army Engineer Research

Direct impacts of outer continental shelf activities on wetland loss in the central Gulf of Mexico

International Nuclear Information System (INIS)

Baumann, R.H.; Turner, R.E.

1990-01-01

The direct impacts of outer continental shelf (OCS) development on recent wetland loss in the northern Gulf of Mexico were quantified using aerial imagery, field surveys, and literature review. The total direct impacts accounted for an estimated 25.6 percent of total net wetland loss within the Louisiana portion of the study area from 1955/56 to 1978. Of the total direct impacts of 73,905 ha, OCS-related activities accounted for 11,589-13,631 ha of the wetland loss during the same time interval. Although this is a substantial areal loss, it represents only 4.0-4.7 percent of the total Louisiana wetland loss from 1955/56 to 1978, and 15.7-18.4 percent of direct impacts. Direct impacts from OCS pipelines averages 2.49 ha/km, lower than published guidelines, and totaled 12,012 ha. Lowest impacts are for backfilled pipelines in the Chenier Plain of western Louisiana and for small young pipeline canals does not appear to be an important factor for total new wetland loss in the coastal zone because few pipelines are open to navigation and, for the examples found, the impact width was not significantly different than for open pipelines closed to navigation. Navigation channels account for a minimum of 16,902 ha of habitat change. Direct impacts per unit length of navigation channel average 20 times greater than pipelines

Freshwater availability and coastal wetland foundation species: ecological transitions along a rainfall gradient

Science.gov (United States)

Osland, Michael J.; Enwright, Nicholas M.; Stagg, Camille L.

2014-01-01

Climate gradient-focused ecological research can provide a foundation for better understanding critical ecological transition points and nonlinear climate-ecological relationships, which is information that can be used to better understand, predict, and manage ecological responses to climate change. In this study, we examined the influence of freshwater availability upon the coverage of foundation plant species in coastal wetlands along a northwestern Gulf of Mexico rainfall gradient. Our research addresses the following three questions: (1) what are the region-scale relationships between measures of freshwater availability (e.g., rainfall, aridity, freshwater inflow, salinity) and the relative abundance of foundation plant species in tidal wetlands; (2) How vulnerable are foundation plant species in tidal wetlands to future changes in freshwater availability; and (3) What is the potential future relative abundance of tidal wetland foundation plant species under alternative climate change scenarios? We developed simple freshwater availability-based models to predict the relative abundance (i.e., coverage) of tidal wetland foundation plant species using climate data (1970-2000), estuarine freshwater inflow-focused data, and coastal wetland habitat data. Our results identify regional ecological thresholds and nonlinear relationships between measures of freshwater availability and the relative abundance of foundation plant species in tidal wetlands. In drier coastal zones, relatively small changes in rainfall could produce comparatively large landscape-scale changes in foundation plant species abundance which would affect some ecosystem good and services. Whereas a drier future would result in a decrease in the coverage of foundation plant species, a wetter future would result in an increase in foundation plant species coverage. In many ways, the freshwater-dependent coastal wetland ecological transitions we observed are analogous to those present in dryland

Influence of seasonal variations in sea level on the salinity regime of a coastal groundwater-fed wetland.

Science.gov (United States)

Wood, Cameron; Harrington, Glenn A

2015-01-01

Seasonal variations in sea level are often neglected in studies of coastal aquifers; however, they may have important controls on processes such as submarine groundwater discharge, sea water intrusion, and groundwater discharge to coastal springs and wetlands. We investigated seasonal variations in salinity in a groundwater-fed coastal wetland (the RAMSAR listed Piccaninnie Ponds in South Australia) and found that salinity peaked during winter, coincident with seasonal sea level peaks. Closer examination of salinity variations revealed a relationship between changes in sea level and changes in salinity, indicating that sea level-driven movement of the fresh water-sea water interface influences the salinity of discharging groundwater in the wetland. Moreover, the seasonal control of sea level on wetland salinity seems to override the influence of seasonal recharge. A two-dimensional variable density model helped validate this conceptual model of coastal groundwater discharge by showing that fluctuations in groundwater salinity in a coastal aquifer can be driven by a seasonal coastal boundary condition in spite of seasonal recharge/discharge dynamics. Because seasonal variations in sea level and coastal wetlands are ubiquitous throughout the world, these findings have important implications for monitoring and management of coastal groundwater-dependent ecosystems. © 2014, National Ground Water Association.

Progress in understanding the importance of coastal wetland nursery habitat to Great Lakes fisheries support

Science.gov (United States)

Great Lakes coastal wetlands provide important habitat for Great Lakes fishes of all life stages. A literature review of ichthyoplankton surveys conducted in Great Lakes coastal wetlands found at least 82 species reported to be captured during the larval stage. Twenty of those sp...

Taxonomic Report on Small Mammals from Two Coastal Wetland ...

African Journals Online (AJOL)

Fiifi Baidoo

Abstract. Surveys of the small mammal populations of two coastal wetlands in Ghana, .... Captured animals were euthanized with chloroform, according to the American Society of. Mammalogy Animal Care and Use Committee guidelines.

Growth Responses of Three Dominant Wetland Plant Species to Various Flooding and Nutrient Levels

Science.gov (United States)

Barrett, S.; Shaffer, G. P.

2017-12-01

Coastal Louisiana is experiencing a greater rate of wetland loss than any other wetland system in the United States. This is primarily due to anthropogenic stressors such as flood control levees, backfilling and development of wetlands, and other hydrologic modifications. Methods employed to mitigate wetland loss include the construction of river diversions and assimilation wetlands, which can provide consistent sources of freshwater influx and nutrients to impounded swamps and marshes. It is well known that prolonged flooding causes strain on wetland plant communities and facilitates or exacerbates wetland degradation. However, because river diversions and assimilation wetlands bring high nutrient loads along with freshwater, there is debate over whether prolonged flooding or high influx of nutrients is the primary cause of stress in river diversion and assimilation wetland discharge areas. This mesocosm experiment addresses this question by isolating the effects of flooding and nutrients on the biomass of baldcypress (Taxodium distichum), maidencane (Panicum hemitomon), and cordgrass (Spartina patens) over the course of a growing season. The results of this study provide clarity as to whether flooding stress, high nutrient loads, or both cause a reduction in wetland plant productivity. By evaluating the growth responses of T. distichum, P. hemitomon, and S. patens at varying nutrient regimes, we gain insight on how these more dominant species will react to high nutrient discharges from large river diversions, such as those proposed in Louisiana's 2017 Master Plan.

Estimating coastal wetland gain and losses in Galveston County and Cameron County, Texas, USA.

Science.gov (United States)

Entwistle, Clare; Mora, Miguel A; Knight, Robert

2018-01-01

Coastal wetlands serve many important ecological services. One of these important ecological services is their use as storm buffers. Coastal wetlands provide habitat for migratory birds and aquatic species and can improve water quality. In the late 1990s, the US Fish and Wildlife Service (USFWS) published a study outlining the trends of coastal wetlands from the 1950s to early 1990s. In the present study, wetland gains and losses were calculated for Galveston County and Cameron County, Texas, USA, between 2001 and 2011. Maps from the National Land Cover Database were used to determine wetland areas for the years 2001, 2006, and 2011. ArcGIS was used to compare land cover between the study periods to determine overall wetland losses and gains. A statistical analysis was performed between wetland loss and population data to determine whether increased population density led to a higher loss of wetlands. Our analysis indicates that wetland loss is still occurring, however at a lower rate of loss (0.14%-0.18% annually) than the USFWS study predicted earlier (2.7%). In addition, the majority of wetland losses were due to conversion to upland areas. We found a positive correlation between increased population density and decreased wetland area; however, the trend was not significant. The present study shows how the majority of wetland loss in Galveston and Cameron counties is occurring as a result of increased upland areas. In addition, the present study shows that the use of online mapping systems can be used as a low-cost alternative to assess land changes when field tests are not feasible. Integr Environ Assess Manag 2018;14:120-129. © 2017 SETAC. © 2017 SETAC.

Tidal Wetlands and Coastal Ocean Carbon Dynamics

Science.gov (United States)

Hopkinson, C.; Wang, S. R.; Forbrich, I.; Giblin, A. E.; Cai, W. J.

2017-12-01

Recent overviews of coastal ocean C dynamics have tidal wetlands in a prominent position: a local sink for atmospheric CO2, a local store of OC, and a source of DIC and OC for the adjacent estuary and nearshore ocean. Over the past decade there have been great strides made in quantifying and understanding these flows and linkages. GPP and R of the wetlands are not nearly as imbalanced as thought 30 yrs ago. Heterotrophy of adjacent estuarine waters is not solely due to the respiration of OC exported from the marsh, rather we see the marsh directly respiring into the water during tidal inundation and accumulated marsh DIC draining into tidal creeks. Organic carbon burial on the marsh is still a relatively minor flux, but it is large relative to marsh NEE. Using literature and unpublished data on marsh DIC export, we used examples from Sapelo Island GA USA and Plum Island MA USA to constrain estimates of NEP and potential OC export. P. There remain large uncertainties in quantifying C dynamics of coupled wetland - estuary systems. Gas exchange from the water to atmosphere is one of the largest uncertainties. Work at Sapelo suggests that upwards of 40% of all daily exchange occurs from water flooding the marsh, which is but a few hours a day. This estimate is based on the intercept value for gas exchange vs wind velocity. Another major uncertainty comes from converting between O2 based estimates of metabolism to C. At Sapelo we find PQ and RQ values diverging greatly from Redfield. Finally, C dynamics of the coastal ocean, especially the role of tidal wetlands is likely to change substantially in the future. Studies at Plum Island show a reversal of the 4000 yr process of marsh progradation with marshes eroding away at their edges because of inadequate sediment supply and rising sea level. The fate of eroded OC is questionable. Landward transgression with SLR is the only likely counter to continued wetland loss - but that's a complex social issue requiring new

Fish assemblages, connectivity, and habitat rehabilitation in a diked Great Lakes coastal wetland complex

Science.gov (United States)

Kowalski, Kurt P.; Wiley, Michael J.; Wilcox, Douglas A.

2014-01-01

Fish and plant assemblages in the highly modified Crane Creek coastal wetland complex of Lake Erie were sampled to characterize their spatial and seasonal patterns and to examine the implications of the hydrologic connection of diked wetland units to Lake Erie. Fyke netting captured 52 species and an abundance of fish in the Lake Erie–connected wetlands, but fewer than half of those species and much lower numbers and total masses of fish were captured in diked wetland units. Although all wetland units were immediately adjacent to Lake Erie, there were also pronounced differences in water quality and wetland vegetation between the hydrologically isolated and lake-connected wetlands. Large seasonal variations in fish assemblage composition and biomass were observed in connected wetland units but not in disconnected units. Reestablishment of hydrologic connectivity in diked wetland units would allow coastal Lake Erie fish to use these vegetated habitats seasonally, although connectivity does appear to pose some risks, such as the expansion of invasive plants and localized reductions in water quality. Periodic isolation and drawdown of the diked units could still be used to mimic intermediate levels of disturbance and manage invasive wetland vegetation.

Analysing how plants in coastal wetlands respond to varying tidal regimes throughout their life cycles.

Science.gov (United States)

Xie, Tian; Cui, Baoshan; Li, Shanze

2017-10-15

Important to conserve plant species in coastal wetlands throughout their life cycle. All life stages in these habitats are exposed to varying tidal cycles. It is necessary to investigate all life stages as to how they respond to varying tidal regimes. We examine three wetlands containing populations of an endangered halophyte species, each subjected to different tidal regimes: (1). wetlands completely closed to tidal cycles; (2). wetlands directly exposed to tidal cycles (3). wetlands exposed to a partially closed tidal regime. Our results showed that the most threatened stage varied between wetlands subjected to these varying tidal regimes. We hypothesis that populations of this species have adapted to these different tidal regimes. Such information is useful in developing management options for coastal wetlands and modifying future barriers restricting tidal flushing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Monitoring coastal wetlands in a highly dynamic tropical environment

International Nuclear Information System (INIS)

Saynor, M.J.; Finlayson, C.M.; Spiers, A.; Eliot, I.

2001-01-01

The Alligator Rivers Region in the wet-dry tropics of northern Australia has been selected by government and collaborating agencies as a key study area for the monitoring of natural and human-induced coastal change. The Region contains the floodplain wetlands of Kakadu National Park which have been recognised internationally for their natural and cultural heritage value. A coastal monitoring program for assessing and monitoring environmental change in the Alligator Rivers Region has been established at the Environmental Research Institute of the Supervising Scientist. This program has developed a regional capacity to measure and assess change on the wetlands, floodplains and coastline within the region. Field assessment and monitoring procedures have been developed for the program. The assessment procedures require use of georeferencing and data handling techniques to facilitate comparison and relational overlay of a wide variety of information. Monitoring includes regular survey of biophysical and cultural processes on the floodplains; such as the extension of tidal creeks and mangroves, shoreline movement, dieback in Melaleuca wetlands, and weed invasion of freshwater wetlands. A differential Global Positioning System is used to accurately georeference spatial data and a Geographic Information System is then used to store and assess information. The assessment and monitoring procedures can be applied to the wet-dry tropics in general. These studies are all particularly pertinent with the possibility of greenhouse gases causing global warming and potential sea-level rise, a major possible threat to the valued wetlands of Kakadu National Park, and across the wet-dry tropics in general

The present and future role of coastal wetland vegetation in protecting shorelines: Answering recent challenges to the paradigm

Science.gov (United States)

Gedan, Keryn B.; Kirwan, Matthew L.; Wolanski, Eric; Barbier, Edward B.; Silliman, Brian R.

2011-01-01

For more than a century, coastal wetlands have been recognized for their ability to stabilize shorelines and protect coastal communities. However, this paradigm has recently been called into question by small-scale experimental evidence. Here, we conduct a literature review and a small meta-analysis of wave attenuation data, and we find overwhelming evidence in support of established theory. Our review suggests that mangrove and salt marsh vegetation afford context-dependent protection from erosion, storm surge, and potentially small tsunami waves. In biophysical models, field tests, and natural experiments, the presence of wetlands reduces wave heights, property damage, and human deaths. Meta-analysis of wave attenuation by vegetated and unvegetated wetland sites highlights the critical role of vegetation in attenuating waves. Although we find coastal wetland vegetation to be an effective shoreline buffer, wetlands cannot protect shorelines in all locations or scenarios; indeed large-scale regional erosion, river meandering, and large tsunami waves and storm surges can overwhelm the attenuation effect of vegetation. However, due to a nonlinear relationship between wave attenuation and wetland size, even small wetlands afford substantial protection from waves. Combining man-made structures with wetlands in ways that mimic nature is likely to increase coastal protection. Oyster domes, for example, can be used in combination with natural wetlands to protect shorelines and restore critical fishery habitat. Finally, coastal wetland vegetation modifies shorelines in ways (e.g. peat accretion) that increase shoreline integrity over long timescales and thus provides a lasting coastal adaptation measure that can protect shorelines against accelerated sea level rise and more frequent storm inundation. We conclude that the shoreline protection paradigm still stands, but that gaps remain in our knowledge about the mechanistic and context-dependent aspects of shoreline

Organic and Inorganic Matter in Louisiana Coastal Waters: Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi Regions.

Science.gov (United States)

Chromophoric dissolved organic matter (CDOM) spectral absorption, dissolved organic carbon (DOC) concentration, and the particulate fraction of inorganic (PIM) and organic matter (POM) were measured in Louisiana coastal waters at Vermilion, Atchafalaya, Terrebonne, Barataria, and...

Challenges of ecosystem restoration in Louisiana - availability of sediment and its management

Science.gov (United States)

Khalil, S. M.; Freeman, A. M.

2015-03-01

Human intervention has impaired the Mississippi River's ability to deliver sediment to its delta wetlands, and as a consequence acute land loss in coastal Louisiana has resulted in an unprecedented ecocatastrophe. To mitigate this degradation, an unparalleled restoration effort is underway. For this effort to be successful and sustainable, various sediment input mechanisms must be integrated, including: building appropriate sediment-diversions; beneficially using the millions of cubic metres of sediment dredged annually from navigational channels; harvesting deposits of sand and suitable sediment from the river and offshore; and related sediment management activities that are compatible with other uses of the river. A comprehensive sediment management plan has been developed to identify and delineate potential sediment sources for restoration, and to provide a framework for managing sediment resources wisely, cost effectively, and in a systematic manner. The Louisiana Sediment Management Plan provides regional strategies for improved comprehensive management of Louisiana's limited sediment resources.

Simulation of integrated surface-water/ground-water flow and salinity for a coastal wetland and adjacent estuary

Science.gov (United States)

Langevin, C.; Swain, E.; Wolfert, M.

2005-01-01

The SWIFT2D surface-water flow and transport code, which solves the St Venant equations in two dimensions, was coupled with the SEAWAT variable-density ground-water code to represent hydrologic processes in coastal wetlands and adjacent estuaries. A sequentially coupled time-lagged approach was implemented, based on a variable-density form of Darcy's Law, to couple the surface and subsurface systems. The integrated code also represents the advective transport of salt mass between the surface and subsurface. The integrated code was applied to the southern Everglades of Florida to quantify flow and salinity patterns and to evaluate effects of hydrologic processes. Model results confirm several important observations about the coastal wetland: (1) the coastal embankment separating the wetland from the estuary is overtopped only during tropical storms, (2) leakage between the surface and subsurface is locally important in the wetland, but submarine ground-water discharge does not contribute large quantities of freshwater to the estuary, and (3) coastal wetland salinities increase to near seawater values during the dry season, and the wetland flushes each year with the onset of the wet season. ?? 2005 Elsevier B.V. All rights reserved.

Trends in Accretion Rates of Riverine Sediments in a Distal Bay and Wetlands Using 7-Beryllium as a Tracer: Fourleague Bay, Louisiana.

Science.gov (United States)

Restreppo, G. A.; Bentley, S. J.; Wang, J.; Xu, K.

2017-12-01

To combat land loss along the Mississippi River Delta, Louisiana has launched a historic campaign to sustain and regrow coastal lands using, in part, sediment diversions. Previous research has focused primarily on sand sized sediment load, which is usually deposited proximal to a river's delta or a diversion's outlet. Fine sediments constitute the majority of sediment load in the Mississippi, but are under-studied with respect to dispersal processes, particularly in terms of sediment supply to distal deltaic bays and wetlands. The Atchafalaya River and associated wetlands serve as prime study areas for this purpose. Bimonthly time-series push cores were collected from May 2015 to May 2016 along ten sites within Fourleague Bay, Louisiana. Fourleague Bay has remained stable against the deteriorative effects of relative sea level rise, standing out along Louisiana's declining coastline. Of the ten field sites, five are located across a longitudinal transect in the middle bay, while the other five are located in adjacent marshes. All sites fall within 10 to 30 km of the Atchafalaya Delta, extending south towards the Gulf of Mexico. Cores were extruded in 2 cm intervals, dried, ground, and analyzed via gamma spectrometry for the presence of 7Be. Inventories of 7Be were then calculated and used to determine daily mass accretion rate (MAR) over twelve months. Average MAR values for the bay and the marshes are compared with Atchafalaya River discharge, wind data, and atmospheric pressure through the year of sampling. Peak marsh MAR, 0.88 ± 0.20 kg m-2 d-1, occurs just after historically high river discharge. Peak bay MAR, 1.2 ± 0.67 kg m-2 d-1, occurs during seasonal low river discharge and calm winds. Average bay and marsh MARs have a moderate to strong, negative correlation when compared. Results indicate sediment bypass of the bay floor during periods of moderate to high river discharge, entering the marshes directly when inundation occurs and enhanced by the passage

Preparing for Sea-level Rise: Conflicts and Opportunities in Coastal Wetlands Coexisting with Infrastructure

Science.gov (United States)

Rodriguez, J. F.; Saco, P. M.; Sandi, S. G.; Saintilan, N.; Riccardi, G.

2017-12-01

Even though on a large scale the sustainability and resilience of coastal wetlands to sea-level rise depends on the slope of the landscape and a balance between the rates of soil accretion and the sea-level rise, local man-made flow disturbances can have comparable effects. Coastal infrastructure controlling flow in the wetlands can pose an additional constraint on the adaptive capacity of these ecosystems, but can also present opportunities for targeted flow management to increase their resilience. Coastal wetlands in SE Australia are heavily managed and typically present infrastructure including flow control devices. How these flow control structures are operated respond to different ecological conservation objectives (i.e. bird, frog or fish habitat) that can sometimes be mutually exclusive. For example, promoting mangrove establishment to enhance fish habitat results in saltmarsh decline thus affecting bird habitat. Moreover, sea-level rise will change hydraulic conditions in wetlands and may result in some flow control structures and strategies becoming obsolete or even counterproductive. In order to address these problems and in support of future management of flows in coastal wetlands, we have developed a predictive tool for long-term wetland evolution that incorporates the effects of infrastructure and other perturbations to the tidal flow within the wetland (i.e. vegetation resistance) and determines how these flow conditions affect vegetation establishment and survival. We use the model to support management and analyse different scenarios of sea-level rise and flow control measures aimed at preserving bird habitat. Our results show that sea-level rise affects the efficiency of management measures and in some cases may completely override their effect. It also shows the potential of targeted flow management to compensate for the effects of sea-level rise.

REMOTE DETENTION OF INVASIVE AND OPPORTUNISTIC PLANT SPECIES IN GREAT LAKES COASTAL WETLANDS

Science.gov (United States)

Invasive and opportunistic plant species have been associated with wetland disturbance. Increases in the abundance of plant species such as common reed (Phragmites australis) in coastal Great Lakes wetlands are hypothesized to occur with shifts toward drier hydrologic regimes, fr...

Hurricane-induced failure of low salinity wetlands

Science.gov (United States)

Howes, Nick C.; FitzGerald, Duncan M.; Hughes, Zoe J.; Georgiou, Ioannis Y.; Kulp, Mark A.; Miner, Michael D.; Smith, Jane M.; Barras, John A.

2010-01-01

During the 2005 hurricane season, the storm surge and wave field associated with Hurricanes Katrina and Rita eroded 527 km2 of wetlands within the Louisiana coastal plain. Low salinity wetlands were preferentially eroded, while higher salinity wetlands remained robust and largely unchanged. Here we highlight geotechnical differences between the soil profiles of high and low salinity regimes, which are controlled by vegetation and result in differential erosion. In low salinity wetlands, a weak zone (shear strength 500–1450 Pa) was observed ∼30 cm below the marsh surface, coinciding with the base of rooting. High salinity wetlands had no such zone (shear strengths > 4500 Pa) and contained deeper rooting. Storm waves during Hurricane Katrina produced shear stresses between 425–3600 Pa, sufficient to cause widespread erosion of the low salinity wetlands. Vegetation in low salinity marshes is subject to shallower rooting and is susceptible to erosion during large magnitude storms; these conditions may be exacerbated by low inorganic sediment content and high nutrient inputs. The dramatic difference in resiliency of fresh versus more saline marshes suggests that the introduction of freshwater to marshes as part of restoration efforts may therefore weaken existing wetlands rendering them vulnerable to hurricanes. PMID:20660777

Leveraging Carbon Cycling in Coastal Wetlands for Habitat Conservation: Blue Carbon Policy Opportunities (Invited)

Science.gov (United States)

Sutton-Grier, A.

2013-12-01

Recent scientific studies suggest that the carbon sequestered and stored in coastal wetlands (specifically mangroves, salt marshes, and seagrass meadows) is an important, previously not well-recognized service provided by these ecosystems. Coastal wetlands have unique characteristics that make them incredibly efficient, natural carbon sinks with most carbon stored belowground in soils. Based on this new scientific evidence, there is growing interest in leveraging the carbon services of these habitats (termed 'blue carbon') to develop new policy opportunities to protect and restore coastal wetlands around the globe. The overall goal is to take full advantage of the carbon services of these habitats in order to ensure and maintain the many benefits provided to society by these habitats - including natural climate, food security, and storm protection benefits - and to enhance the resiliency of coastal communities and economies around the world. This presentation will give an update on some of the policy opportunities including: (1) examining how the implementation of U.S. federal policies can be expanded to include carbon services of ecosystems in order to improve management and decision making; (2) developing an international blue carbon community of science and practice to provide best practice guidance for protection and restoration of blue carbon habitats; and (3) developing innovative financing mechanisms for coastal conservation including carbon market credits for wetlands. Finally, the presentation will conclude by highlighting some of the most pressing blue carbon scientific gaps that need to be filled in order to support these developing policies.

Validation and Comparison of a Model of the Effect of Sea-Level Rise on Coastal Wetlands.

Science.gov (United States)

Mogensen, Laura A; Rogers, Kerrylee

2018-01-22

Models are used to project coastal wetland distribution under future sea-level rise scenarios to assist decision-making. Model validation and comparison was used to investigate error and uncertainty in the Sea Level Affecting Marshes Model, a readily available model with minimal validation, particularly for wetlands beyond North America. Accurate parameterisation is required to improve the performance of the model, and indeed any spatial model. Consideration of tidal attenuation further enhances model performance, particularly for coastal wetlands located within estuaries along wave-dominated coastlines. The model does not simulate vegetation changes that are known to occur, particularly when sedimentation exceeds rates of sea-level rise resulting in shoreline progradation. Model performance was reasonable over decadal timescales, decreasing as the time-scale of retrospection increased due to compounding of errors. Comparison with other deterministic models showed reasonable agreement by 2100. However, given the uncertainty of the future and the unpredictable nature of coastal wetlands, it is difficult to ascertain which model could be realistic enough to meet its intended purpose. Model validation and comparison are useful for assessing model efficacy and parameterisation, and should be applied before application of any spatially explicit model of coastal wetland response to sea-level rise.

Coastal Carbon Dynamics as a New Chapter in SOCCR2: Tidal Wetlands and Estuaries

Science.gov (United States)

Windham-Myers, L.; Megonigal, P.; Cai, W. J.; Hopkinson, C.; Wang, A. Z.; Andersson, A. J.; Hinson, A.; Lagomasino, D.; Peteet, D. M.; Giri, C. P.; Howard, J.; Tang, J.; Crosswell, J.; Martin Hernandez-Ayon, J. M.; Dunton, K. H.; Kroeger, K. D.; Paulsen, M. L.; Allison, M. A.; Siedlecki, S. A.; Alin, S. R.; Hu, X.; Tzortziou, M.; Najjar, R.; Schafer, K. V.; Watson, E.; Pidgeon, E.

2016-12-01

Estuaries and tidal wetlands have been identified as distinct landscape elements for carbon cycling, worthy of a chapter in the pending State of the Carbon Cycle Report - version 2. Despite relatively small aerial coverage compared to other subsystems, tidal wetlands and estuaries have the greatest influence on carbon dynamics of any coastal ocean subsystem. As conduits that filter all material passing between land and the sea, they also exhibit the highest transfer rates of CO2 with the atmosphere of any of the coastal ocean subsystems. Carbon dynamics in estuaries and wetlands are constantly changing, reflecting geomorphic and ecological responses to long and short-term perturbations in external drivers such as sea-level rise, climate change, nutrient loading and land-use change. The influence of these drivers are profound in coastal systems, often more so than in inland wetlands or open ocean environments, and thus require distinct attention to patterns and processes associated with coastal ecosystem functioning, including carbon sequestration services in tidal wetland soils. This new chapter focusses on data sources available in North America to: (1) assess the current state of carbon stocks and fluxes in coastal settings, (2) document understanding of drivers associated with significant fluxes and stocks, and (3) synthesize carbon dynamics from a global context to regional perspectives (East, West, Gulf and high-latitude coastlines). Insights from remote sensing, in situ field data, and numerical models have advanced our ability to monitor and project carbon cycling in this dynamic and narrow fringe at the land-ocean interface. This synthetic chapter will address how these advances can help in decision making, as well as address remaining gaps in our knowledge and monitoring capabilities for these diverse and productive habitats.

The potential accumulation of polycyclic aromatic hydrocarbons in phytoplankton and bivalves in Can Gio coastal wetland, Vietnam.

Science.gov (United States)

Thuy, Hoang Thi Thanh; Loan, Tu Thi Cam; Phuong, Trinh Hong

2018-05-12

Polycyclic aromatic hydrocarbons (PAHs) are one of the most important classes of anthropogenic persistent organic contaminants in the marine environment. This review discusses a whole range of findings that address various aspects of the bioaccumulation of PAHs in two common marine biota (phytoplankton and bivalves) globally and especially for Can Gio coastal wetland, Vietnam. The published information and collected data on the bioconcentration and accumulation mechanisms of PAHs as well as implications for Can Gio coastal wetland are compiled for phytoplankton and bivalves. PAHs are still released to Can Gio coastal environments from various sources and then transported to coastal environments through various physical processes; they may enter marine food chains and be highly accumulated in phytoplankton and bivalves. Thus, PAHs' bioaccumulation should be considered as one important criterion to assess the water's quality, directly linked to human health due to seafood consumption. Ecologically, Can Gio coastal wetland plays an important role to the South Vietnam key economic zone. However, it is also an area of potential PAHs inputs. With the abundant phytoplankton and bivalves in Can Gio coastal wetland, the PAHs bioaccumulation in these biota is inevitably detected. Thus, further study on the bioavailability of these contaminants is urgently needed in order to mitigate their negative effects and protect the ecosystems.

Delta lobe degradation and hurricane impacts governing large-scale coastal behavior, South-central Louisiana, USA

Science.gov (United States)

Miner, M.D.; Kulp, M.A.; FitzGerald, D.M.; Flocks, J.G.; Weathers, H.D.

2009-01-01

A large deficit in the coastal sediment budget, high rates of relative sea-level rise (???0.9 cm/year), and storm-induced current and wave erosion are forcing barrier shoreface retreat along the periphery of the Mississippi River delta plain. Additionally, conversion of interior wetlands to open water has increased the bay tidal prism, resulting in degradation of barrier islands due to inlet widening, formation of new inlets, and sediment sequestration at ebb-tidal deltas. Single-beam bathymetric surveys along a 165-km stretch of south-central Louisiana barrier coast, from Raccoon Point in Terrebonne Parish to Sandy Point in Plaquemines Parish, were conducted in 2006. These data, combined with historical bathymetry from three time periods (dating to the 1880s), provide a series of digital elevation models that were used to calculate sediment volumetric changes and determine long-term erosional-depositional trends. Dominant patterns during the 125-year period include (1) erosion of ???1.6????????109 m3 from the shoreface, forcing up to 3 km of shoreface retreat, (2) sediment deposition in coastal bights and at ebb-tidal deltas, and (3) a combined increase in tidal inlet cross-sectional area from ???41,400 m2 to ???139,500 m 2. Bathymetric and shoreline change datasets separated by shorter time periods (sub-annual) demonstrate that these long-term trends are driven by processes associated with major hurricane impacts, and that rates of shoreface erosion are an order of magnitude greater during active hurricane seasons compared to long-term trends. ?? 2009 Springer-Verlag.

Monitoring duration and extent of storm-surge and flooding in Western Coastal Louisiana marshes with Envisat ASAR data

Science.gov (United States)

Ramsey, E.; Lu, Z.; Suzuoki, Y.; Rangoonwala, A.; Werle, D.

2011-01-01

Inundation maps of coastal marshes in western Louisiana were created with multitemporal Envisat Advanced Synthetic Aperture (ASAR) scenes collected before and during the three months after Hurricane Rita landfall in September 2005. Corroborated by inland water-levels, 7 days after landfall, 48% of coastal estuarine and palustrine marshes remained inundated by storm-surge waters. Forty-five days after landfall, storm-surge inundated 20% of those marshes. The end of the storm-surge flooding was marked by an abrupt decrease in water levels following the passage of a storm front and persistent offshore winds. A complementary dramatic decrease in flood extent was confirmed by an ASAR-derived inundation map. In nonimpounded marshes at elevations ;80 cm during the first month after Rita landfall. After this initial period, drainage from marshes-especially impounded marshes-was hastened by the onset of offshore winds. Following the abrupt drops in inland water levels and flood extent, rainfall events coinciding with increased water levels were recorded as inundation re-expansion. This postsurge flooding decreased until only isolated impounded and palustrine marshes remained inundated. Changing flood extents were correlated to inland water levels and largely occurred within the same marsh regions. Trends related to incremental threshold increases used in the ASAR change-detection analyses seemed related to the preceding hydraulic and hydrologic events, and VV and HH threshold differences supported their relationship to the overall wetland hydraulic condition.

Environmental Analysis of Lake Pontchartrain, Louisiana, Its Surrounding Wetlands, and Selected Land Uses. Volume 2.

Science.gov (United States)

1980-02-01

CHAPTER 1: PRELIMINARY MODELING OF THE LAKE PONTCHARTRAIN ECOSYSTEM BY COMPUTER SIMULATIONS Janes H. Stone and Linda A. Deegan ...related to the extent and productivity of intertidal wetlands ( Craig et al. 1979). The role of coastal wetlands in estuarine areas has been well documented...site arid a bottomland harlwood stt c ill I Iouisiana swamp. Amer. J. Bot. 63 (10):1354-1364. Craig , N. J., R. E. Turner, aird J. W. Day, Jr. 197

Carbon stocks of tropical coastal wetlands within the karstic landscape of the Mexican Caribbean.

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Maria Fernanda Adame

Full Text Available Coastal wetlands can have exceptionally large carbon (C stocks and their protection and restoration would constitute an effective mitigation strategy to climate change. Inclusion of coastal ecosystems in mitigation strategies requires quantification of carbon stocks in order to calculate emissions or sequestration through time. In this study, we quantified the ecosystem C stocks of coastal wetlands of the Sian Ka'an Biosphere Reserve (SKBR in the Yucatan Peninsula, Mexico. We stratified the SKBR into different vegetation types (tall, medium and dwarf mangroves, and marshes, and examined relationships of environmental variables with C stocks. At nine sites within SKBR, we quantified ecosystem C stocks through measurement of above and belowground biomass, downed wood, and soil C. Additionally, we measured nitrogen (N and phosphorus (P from the soil and interstitial salinity. Tall mangroves had the highest C stocks (987±338 Mg ha(-1 followed by medium mangroves (623±41 Mg ha(-1, dwarf mangroves (381±52 Mg ha(-1 and marshes (177±73 Mg ha(-1. At all sites, soil C comprised the majority of the ecosystem C stocks (78-99%. Highest C stocks were measured in soils that were relatively low in salinity, high in P and low in N∶P, suggesting that P limits C sequestration and accumulation potential. In this karstic area, coastal wetlands, especially mangroves, are important C stocks. At the landscape scale, the coastal wetlands of Sian Ka'an covering ≈172,176 ha may store 43.2 to 58.0 million Mg of C.

Stress triggering of earthquakes and subsidence in the Louisiana coastal zone due to hydrocarbon production

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Mallman, Ellen P.

This thesis presents contributions towards better understanding of the interaction between earthquakes through elastic stress triggering and the role of hydrocarbon production on subsidence and land loss in southern Louisiana. The first issue addressed in this thesis is that of the role of static stress changes on earthquake triggering. The first study investigated whether observed changes in seismicity rate following the 1992 Landers, California and 1995 Kobe, Japan earthquakes are accurately predicted by elastic Coulomb stress transfer models. The analyses found that for all the tested DeltaCFS models wherever seismicity rate changes could be resolved the rate increased regardless of whether the DeltaCFS theoretically promoted or inhibited failure. The second study the common definition of a stress shadow was extended to independently test the stress shadow hypothesis using a global catalog of seismicity. The analyses indicated that while stress shadows are subtle, they are present in the global catalog. It also explains why "classical" stress shadows, similar to what was observed following the 1906 San Francisco earthquake are rarely observed for individual main shocks. The second issue addressed in this thesis is the role of hydrocarbon production on subsidence and land loss in the Louisiana Coastal Zone. The two studies in this thesis extend previous work by modeling the effect of oil and gas production in the region in two ways. First, multiple producing oil and gas fields and multiple epochs of leveling data are considered to provide constraints on predicted subsidence. Second, the role of compaction of the reservoir bounding shales on the regional subsidence signal is included. The results of the two studies on the role of hydrocarbon production on subsidence in the Louisiana Coastal Zone indicate that regional models of subsidence must include the effects of production-induced subsidence due to both sands and shales, but that this can not account for the

Predicting Disturbance-driven Impacts on Ecosystem Services in Coastal Wetlands

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Rajan, S.; Crawford, P.; Kleinhuizen, A.; Mortazavi, B.; Sobecky, P.

2017-12-01

Natural and human-induced disturbances pose significant threats to the health and long-term productivity of Alabama coastal wetlands. As wetlands are a vital state resource, decisions on management, restoration, and remediation require actionable data if socio-economic demands are to be balanced with efforts to sustain these habitats. In 2010, the BP oil spill was a large and severe disturbance that threatened coastal Gulf ecosystem services. The largest marine oil spill to date served to highlight fundamental gaps in our knowledge of oil-induced disturbances and the resiliency and restoration of coastal Alabama wetland functions. To address these gaps, a year-long mesocosm study was conducted to investigate oil-induced effects on (i) plant-microbial interactions, (ii) microbial and plant biodiversity, and, (iii) the contributions of microbial genetic biodiversity to ecosystems services. In this study, Avicennia germinans (black mangrove), a C3 plant that grows from the tropics to warm temperate latitudes, were grown with or without mono- and polyculture mixtures of Spartina alterniflora, a C4 plant. At an interval of 3-months, oil was introduced as a pulse disturbance to achieve a concentration of 4000 ppm. Molecular-based analyses of microbial community biodiversity, genetic diversity, and functional metabolic genes were compared to controls (i.e., no oil disturbance). To assess the oil-induced effects on the nitrogen (N) cycle, measurements of denitrification and N fixation processes were conducted. Our results showed that community diversity and phylogenetic diversity significantly changed and that the oil disturbance contributed to the creation of niches for distinct microbial types. The abundance of N-fixing microbial types increased as the abundance of denitrifying microbial types decreased as a result of the oil disturbance. As denitrification is an ecosystem service that directly contributes to removing nitrate (NO3-) loading to coastal zones, impairment

Hydrologic and Vegetative Removal of Cryptosporidium parvum, Giardia lamblia, and Toxoplasma gondii Surrogate Microspheres in Coastal Wetlands

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Hogan, Jennifer N.; Daniels, Miles E.; Watson, Fred G.; Oates, Stori C.; Miller, Melissa A.; Conrad, Patricia A.; Shapiro, Karen; Hardin, Dane; Dominik, Clare; Melli, Ann; Jessup, David A.

2013-01-01

Constructed wetland systems are used to reduce pollutants and pathogens in wastewater effluent, but comparatively little is known about pathogen transport through natural wetland habitats. Fecal protozoans, including Cryptosporidium parvum, Giardia lamblia, and Toxoplasma gondii, are waterborne pathogens of humans and animals, which are carried by surface waters from land-based sources into coastal waters. This study evaluated key factors of coastal wetlands for the reduction of protozoal parasites in surface waters using settling column and recirculating mesocosm tank experiments. Settling column experiments evaluated the effects of salinity, temperature, and water type (“pure” versus “environmental”) on the vertical settling velocities of C. parvum, G. lamblia, and T. gondii surrogates, with salinity and water type found to significantly affect settling of the parasites. The mesocosm tank experiments evaluated the effects of salinity, flow rate, and vegetation parameters on parasite and surrogate counts, with increased salinity and the presence of vegetation found to be significant factors for removal of parasites in a unidirectional transport wetland system. Overall, this study highlights the importance of water type, salinity, and vegetation parameters for pathogen transport within wetland systems, with implications for wetland management, restoration efforts, and coastal water quality. PMID:23315738

Stimulating a Great Lakes coastal wetland seed bank using portable cofferdams: implications for habitat rehabilitation

Science.gov (United States)

Kowalski, K.P.; Wilcox, D.A.; Wiley, M.J.

2009-01-01

Coastal wetland seed banks exposed by low lake levels or through management actions fuel the reestablishment of emergent plant assemblages (i.e., wetland habitat) critical to Great Lakes aquatic biota. This project explored the effectiveness of using portable, water-filled cofferdams as a management tool to promote the natural growth of emergent vegetation from the seed bank in a Lake Erie coastal wetland. A series of dams stretching approximately 450??m was installed temporarily to isolate hydrologically a 10-ha corner of the Crane Creek wetland complex from Lake Erie. The test area was dewatered in 2004 to mimic a low-water year, and vegetation sampling characterized the wetland seed bank response at low, middle, and high elevations in areas open to and protected from bird and mammal herbivory. The nearly two-month drawdown stimulated a rapid seed-bank-driven response by 45 plant taxa. Herbivory had little effect on plant species richness, regardless of the location along an elevation gradient. Inundation contributed to the replacement of immature emergent plant species with submersed aquatic species after the dams failed and were removed prematurely. This study revealed a number of important issues that must be considered for effective long-term implementation of portable cofferdam technology to stimulate wetland seed banks, including duration of dewatering, product size, source of clean water, replacement of damaged dams, and regular maintenance. This technology is a potentially important tool in the arsenal used by resource managers seeking to rehabilitate the functions and values of Great Lakes coastal wetland habitats.

Environmental impact of geopressure - geothermal cogeneration facility on wetland resources and socioeconomic characteristics in Louisiana Gulf Coast region. Final report, October 10, 1983-September 31, 1984

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Smalley, A.M.; Saleh, F.M.S.; Fontenot, M.

1984-08-01

Baseline data relevant to air quality are presented. The following are also included: geology and resource assessment, design well prospects in southwestern Louisiana, water quality monitoring, chemical analysis subsidence, microseismicity, geopressure-geothermal subsidence modeling, models of compaction and subsidence, sampling handling and preparation, brine chemistry, wetland resources, socioeconomic characteristics, impacts on wetlands, salinity, toxic metals, non-metal toxicants, temperature, subsidence, and socioeconomic impacts. (MHR)

Causal mechanisms of soil organic matter decomposition: Deconstructing salinity and flooding impacts in coastal wetlands

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Stagg, Camille L.; Schoolmaster, Donald; Krauss, Ken W.; Cormier, Nicole; Conner, William H.

2017-01-01

Coastal wetlands significantly contribute to global carbon storage potential. Sea-level rise and other climate change-induced disturbances threaten coastal wetland sustainability and carbon storage capacity. It is critical that we understand the mechanisms controlling wetland carbon loss so that we can predict and manage these resources in anticipation of climate change. However, our current understanding of the mechanisms that control soil organic matter decomposition, in particular the impacts of elevated salinity, are limited, and literature reports are contradictory. In an attempt to improve our understanding of these complex processes, we measured root and rhizome decomposition and developed a causal model to identify and quantify the mechanisms that influence soil organic matter decomposition in coastal wetlands that are impacted by sea-level rise. We identified three causal pathways: 1) a direct pathway representing the effects of flooding on soil moisture, 2) a direct pathway representing the effects of salinity on decomposer microbial communities and soil biogeochemistry, and 3) an indirect pathway representing the effects of salinity on litter quality through changes in plant community composition over time. We used this model to test the effects of alternate scenarios on the response of tidal freshwater forested wetlands and oligohaline marshes to short- and long-term climate-induced disturbances of flooding and salinity. In tidal freshwater forested wetlands, the model predicted less decomposition in response to drought, hurricane salinity pulsing, and long-term sea-level rise. In contrast, in the oligohaline marsh, the model predicted no change in response to sea-level rise, and increased decomposition following a drought or a hurricane salinity pulse. Our results show that it is critical to consider the temporal scale of disturbance and the magnitude of exposure when assessing the effects of salinity intrusion on carbon mineralization in coastal

Multi-temporal Land Use Mapping of Coastal Wetlands Area using Machine Learning in Google Earth Engine

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Farda, N. M.

2017-12-01

Coastal wetlands provide ecosystem services essential to people and the environment. Changes in coastal wetlands, especially on land use, are important to monitor by utilizing multi-temporal imagery. The Google Earth Engine (GEE) provides many machine learning algorithms (10 algorithms) that are very useful for extracting land use from imagery. The research objective is to explore machine learning in Google Earth Engine and its accuracy for multi-temporal land use mapping of coastal wetland area. Landsat 3 MSS (1978), Landsat 5 TM (1991), Landsat 7 ETM+ (2001), and Landsat 8 OLI (2014) images located in Segara Anakan lagoon are selected to represent multi temporal images. The input for machine learning are visible and near infrared bands, PCA band, invers PCA bands, bare soil index, vegetation index, wetness index, elevation from ASTER GDEM, and GLCM (Harralick) texture, and also polygon samples in 140 locations. There are 10 machine learning algorithms applied to extract coastal wetlands land use from Landsat imagery. The algorithms are Fast Naive Bayes, CART (Classification and Regression Tree), Random Forests, GMO Max Entropy, Perceptron (Multi Class Perceptron), Winnow, Voting SVM, Margin SVM, Pegasos (Primal Estimated sub-GrAdient SOlver for Svm), IKPamir (Intersection Kernel Passive Aggressive Method for Information Retrieval, SVM). Machine learning in Google Earth Engine are very helpful in multi-temporal land use mapping, the highest accuracy for land use mapping of coastal wetland is CART with 96.98 % Overall Accuracy using K-Fold Cross Validation (K = 10). GEE is particularly useful for multi-temporal land use mapping with ready used image and classification algorithms, and also very challenging for other applications.

Performance measures for a Mississippi River reintroduction into the forested wetlands of Maurepas Swamp

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Krauss, Ken W.; Shaffer, Gary P.; Keim, Richard F.; Chambers, Jim L.; Wood, William B.; Hartley, Stephen B.

2017-06-09

The use of freshwater diversions (river reintroductions) from the Mississippi River as a restoration tool to rehabilitate Louisiana coastal wetlands has been promoted widely since the first such diversion at Caernarvon became operational in the early 1990s. To date, aside from the Bonnet Carré Spillway (which is designed and operated for flood control), there are only four operational Mississippi River freshwater diversions (two gated structures and two siphons) in coastal Louisiana, and they all target salinity intrusion, shellfish management, and (or) the enhancement of the integrity of marsh habitat. River reintroductions carry small sediment loads for various design reasons, but they can be effective in delivering fresh­water to combat saltwater intrusion and increase the delivery of nutrients and suspended fine-grained sediments to receiving wetlands. River reintroductions may be an ideal restoration tool for targeting coastal swamp forest habitat; much of the area of swamp forest habitat in coastal Louisiana is undergo­ing saltwater intrusion, high rates of submergence, and lack of riverine flow leading to reduced concentrations of important nutrients and suspended sediments, which sustain growth and regeneration, help to aerate swamp soils, and remove toxic compounds from the rhizosphere.The State of Louisiana Coastal Protection and Restora­tion Authority (CPRA) has made it a priority to establish a small freshwater river diversion into a coastal swamp forest located between Baton Rouge and New Orleans, Louisiana, to reintroduce Mississippi River water to Maurepas Swamp. While a full understanding of how a coastal swamp forest will respond to new freshwater loading through a Mississippi River reintroduction is unknown, this report provides guidance based on the available literature for establishing performance measures that can be used for evaluating the effectiveness of a Mississippi River reintroduction into the forested wetlands of Maurepas Swamp

Fish resources of Lagos State coastal wetlands | Ayodele | African ...

African Journals Online (AJOL)

Fishing is the major occupation of the people found along the coastal wetland of Lagos State. Fishing is carried out all the year round. This study examines the fishing Activities, Gear composition and fishing methods in order to obtain the fish species and harvest composition of the study area. This paper is based on the ...

A comparison of the vegetation and soils of natural, restored, and created coastal lowland wetlands in Hawai‘i

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Meris Bantilan-Smith; Gregory L. Bruland; Richard A. MacKenzie; Adonia R. Henry; Christina R. Ryder

2009-01-01

The loss of coastal wetlands throughout the Hawaiian Islands has increased the numbers of created (CW) and restored (RW) wetlands. An assessment of these wetlands has yet to occur, and it has not been determined whether CWs and RWs provide the same functions as natural wetlands (NWs). To address these concerns, vegetation and soil characteristics of 35 wetlands were...

A Carbon Cycle Model for the Social-Ecological Process in Coastal Wetland: A Case Study on Gouqi Island, East China

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Yanxia Li

2017-01-01

Full Text Available Coastal wetlands offer many important ecosystem services both in natural and in social systems. How to simultaneously decrease the destructive effects flowing from human activities and maintaining the sustainability of regional wetland ecosystems are an important issue for coastal wetlands zones. We use carbon credits as the basis for regional sustainable developing policy-making. With the case of Gouqi Island, a typical coastal wetlands zone that locates in the East China Sea, a carbon cycle model was developed to illustrate the complex social-ecological processes. Carbon-related processes in natural ecosystem, primary industry, secondary industry, tertiary industry, and residents on the island were identified in the model. The model showed that 36780 tons of carbon is released to atmosphere with the form of CO2, and 51240 tons of carbon is captured by the ecosystem in 2014 and the three major resources of carbon emission are transportation and tourism development and seawater desalination. Based on the carbon-related processes and carbon balance, we proposed suggestions on the sustainable development strategy of Gouqi Island as coastal wetlands zone.

A Carbon Cycle Model for the Social-Ecological Process in Coastal Wetland: A Case Study on Gouqi Island, East China

Science.gov (United States)

Xiong, Lihu; Zhu, Wenjia

2017-01-01

Coastal wetlands offer many important ecosystem services both in natural and in social systems. How to simultaneously decrease the destructive effects flowing from human activities and maintaining the sustainability of regional wetland ecosystems are an important issue for coastal wetlands zones. We use carbon credits as the basis for regional sustainable developing policy-making. With the case of Gouqi Island, a typical coastal wetlands zone that locates in the East China Sea, a carbon cycle model was developed to illustrate the complex social-ecological processes. Carbon-related processes in natural ecosystem, primary industry, secondary industry, tertiary industry, and residents on the island were identified in the model. The model showed that 36780 tons of carbon is released to atmosphere with the form of CO2, and 51240 tons of carbon is captured by the ecosystem in 2014 and the three major resources of carbon emission are transportation and tourism development and seawater desalination. Based on the carbon-related processes and carbon balance, we proposed suggestions on the sustainable development strategy of Gouqi Island as coastal wetlands zone. PMID:28286690

Coastal bathymetry data collected in 2011 from the Chandeleur Islands, Louisiana

Science.gov (United States)

DeWitt, Nancy T.; Pfeiffer, William R.; Bernier, Julie C.; Buster, Noreen A.; Miselis, Jennifer L.; Flocks, James G.; Reynolds, Billy J.; Wiese, Dana S.; Kelso, Kyle W.

2014-01-01

As part of the Barrier Island Evolution Research project, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off the northern Chandeleur Islands, Louisiana, in June of 2011. The overall objectives of the study are to better understand barrier-island geomorphic evolution, particularly storm-related depositional and erosional processes that shape the islands over annual to interannual timescales (1-5 years). Collection of geophysical data will allow us to identify relationships between the geologic history of the island and its present day morphology and sediment distribution. This mapping effort was the first in a series of three planned surveys in this area. High resolution geophysical data collected in each of three consecutive years along this rapidly changing barrier-island system will provide a unique time-series dataset that will significantly further the analyses and geomorphological interpretations of this and other coastal systems, improving our understanding of coastal response and evolution over short time scales (1-5 years).

North American coastal carbon stocks and exchanges among the coupled ecosystems of tidal wetlands and estuaries

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Windham-Myers, L.; Cai, W. J.

2017-12-01

The development of the 2nd State of the Carbon Cycle Report (SOCCR-2) has recognized a significant role of aquatic ecosystems, including coastal zones, in reconciling some of the gaps associated with the North American carbon (C) budget. Along with a large community of coauthors, we report major C stocks and fluxes for tidal wetlands and estuaries of Canada, Mexico and the United States. We find divergent patterns between these coupled ecosystems, with tidal wetlands largely serving as CO2 sinks (net autotrophic), and open-water estuaries largely serving as CO2 sources (net heterotrophic). We summarized measurements across 4 continental regions - East Coast, Gulf of Mexico, West Coast, and High Latitudes - to assess spatial variability and datagaps in our understanding of coastal C cycling. Subtracting estuarine outgassing of 10 ± 10 Tg C yr-1 from the tidal wetland uptake of 23 ± 10 Tg C yr-1 leaves a net uptake of the combined system of 13 ± 14 Tg C yr-1. High uncertainty for net atmospheric C exchange in this combined coastal system is further complicated by spatially and temporally dynamic boundaries, as well as terrestrial C sources. Tidal wetlands are among the most productive ecosystems on earth and are capable of continuously accumulating organic C in their sediments as a result of environmental conditions that inhibit organic matter decomposition. Estuaries have more interannual variability in C dynamics than those of tidal wetlands, reflecting the estuarine balance of exchanges with terrestrial watersheds, tidal wetlands, and the continental shelf. Whereas tidal, subtidal and estuarine maps are of limited accuracy at larger scales, North America likely represents less than 1/10 of global distributions of coastal wetland habitats. Coupled land-ocean C flux models are increasingly robust but lacking much of the data needed for parameterization and validation. Accurate boundary maps and synoptic monitoring data on air-water CO2 exchange may be developed

Resource competition model predicts zonation and increasing nutrient use efficiency along a wetland salinity gradient

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Schoolmaster, Donald; Stagg, Camille L.

2018-01-01

A trade-off between competitive ability and stress tolerance has been hypothesized and empirically supported to explain the zonation of species across stress gradients for a number of systems. Since stress often reduces plant productivity, one might expect a pattern of decreasing productivity across the zones of the stress gradient. However, this pattern is often not observed in coastal wetlands that show patterns of zonation along a salinity gradient. To address the potentially complex relationship between stress, zonation, and productivity in coastal wetlands, we developed a model of plant biomass as a function of resource competition and salinity stress. Analysis of the model confirms the conventional wisdom that a trade-off between competitive ability and stress tolerance is a necessary condition for zonation. It also suggests that a negative relationship between salinity and production can be overcome if (1) the supply of the limiting resource increases with greater salinity stress or (2) nutrient use efficiency increases with increasing salinity. We fit the equilibrium solution of the dynamic model to data from Louisiana coastal wetlands to test its ability to explain patterns of production across the landscape gradient and derive predictions that could be tested with independent data. We found support for a number of the model predictions, including patterns of decreasing competitive ability and increasing nutrient use efficiency across a gradient from freshwater to saline wetlands. In addition to providing a quantitative framework to support the mechanistic hypotheses of zonation, these results suggest that this simple model is a useful platform to further build upon, simulate and test mechanistic hypotheses of more complex patterns and phenomena in coastal wetlands.

Mercury adsorption in the Mississippi River deltaic plain freshwater marsh soil of Louisiana Gulf coastal wetlands.

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Park, Jong-Hwan; Wang, Jim J; Xiao, Ran; Pensky, Scott M; Kongchum, Manoch; DeLaune, Ronald D; Seo, Dong-Cheol

2018-03-01

Mercury adsorption characteristics of Mississippi River deltaic plain (MRDP) freshwater marsh soil in the Louisiana Gulf coast were evaluated under various conditions. Mercury adsorption was well described by pseudo-second order and Langmuir isotherm models with maximum adsorption capacity of 39.8 mg g -1 . Additional fitting of intraparticle model showed that mercury in the MRDP freshwater marsh soil was controlled by both external surface adsorption and intraparticle diffusion. The partition of adsorbed mercury (mg g -1 ) revealed that mercury was primarily adsorbed into organic-bond fraction (12.09) and soluble/exchangeable fraction (10.85), which accounted for 63.5% of the total adsorption, followed by manganese oxide-bound (7.50), easily mobilizable carbonate-bound (4.53), amorphous iron oxide-bound (0.55), crystalline Fe oxide-bound (0.41), and residual fraction (0.16). Mercury adsorption capacity was generally elevated along with increasing solution pH even though dominant species of mercury were non-ionic HgCl 2 , HgClOH and Hg(OH) 2  at between pH 3 and 9. In addition, increasing background NaCl concentration and the presence of humic acid decreased mercury adsorption, whereas the presence of phosphate, sulfate and nitrate enhanced mercury adsorption. Mercury adsorption in the MRDP freshwater marsh soil was reduced by the presence of Pb, Cu, Cd and Zn with Pb showing the greatest competitive adsorption. Overall the adsorption capacity of mercury in the MRDP freshwater marsh soil was found to be significantly influenced by potential environmental changes, and such factors should be considered in order to manage the risks associated with mercury in this MRDP wetland for responding to future climate change scenarios. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessing the long-term impact of subsidence and global climate change on emergency evacuation routes in coastal Louisiana.

Science.gov (United States)

2012-12-01

Subsidence forecast models for coastal Louisiana were developed to estimate the change in surface elevations of evacuation routes for the years 2015, 2025, 2050, and 2100. Geophysical and anthropogenic subsidence estimates were derived from on-going ...

Thresholds of sea-level rise rate and sea-level acceleration rate in a vulnerable coastal wetland

Science.gov (United States)

Wu, W.; Biber, P.; Bethel, M.

2017-12-01

Feedback among inundation, sediment trapping, and vegetation productivity help maintain coastal wetlands facing sea-level rise (SLR). However, when the SLR rate exceeds a threshold, coastal wetlands can collapse. Understanding the threshold help address the key challenge in ecology - nonlinear response of ecosystems to environmental change, and promote communication between ecologists and policy makers. We studied the threshold of SLR rate and developed a new threshold of SLR acceleration rate on sustainability of coastal wetlands as SLR is likely to accelerate due to the enhanced anthropogenic forces. We developed a mechanistic model to simulate wetland change and derived the SLR thresholds for Grand Bay, MS, a micro-tidal estuary with limited upland freshwater and sediment input in the northern Gulf of Mexico. The new SLR acceleration rate threshold complements the threshold of SLR rate and can help explain the temporal lag before the rapid decline of wetland area becomes evident after the SLR rate threshold is exceeded. Deriving these two thresholds depends on the temporal scale, the interaction of SLR with other environmental factors, and landscape metrics, which have not been fully accounted for before this study. The derived SLR rate thresholds range from 7.3 mm/yr to 11.9 mm/yr. The thresholds of SLR acceleration rate are 3.02×10-4 m/yr2 and 9.62×10-5 m/yr2 for 2050 and 2100 respectively. Based on the thresholds developed, predicted SLR that will adversely impact the coastal wetlands in Grand Bay by 2100 will fall within the likely range of SLR under a high warming scenario (RCP8.5), and beyond the very likely range under a low warming scenario (RCP2.6 or 3), highlighting the need to avoid the high warming scenario in the future if these marshes are to be preserved.

Analysis of fish movements between Great Lakes coastal wetlands and near shore habitat via otolith microchemistry

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Great Lakes coastal wetlands are unique habitats with physical connections with near shore environments. This facilitates the exchange of energy between habitats in a principle known as habitat coupling. Coupling can be facilitated by movements of consumers; however, wetland us...

Thresholds of sea-level rise rate and sea-level rise acceleration rate in a vulnerable coastal wetland.

Science.gov (United States)

Wu, Wei; Biber, Patrick; Bethel, Matthew

2017-12-01

Feedbacks among inundation, sediment trapping, and vegetation productivity help maintain coastal wetlands facing sea-level rise (SLR). However, when the SLR rate exceeds a threshold, coastal wetlands can collapse. Understanding the threshold helps address key challenges in ecology-nonlinear response of ecosystems to environmental change, promotes communication between ecologists and resource managers, and facilitates decision-making in climate change policies. We studied the threshold of SLR rate and developed a new threshold of SLR acceleration rate on sustainability of coastal wetlands as SLR is likely to accelerate due to enhanced anthropogenic forces. Deriving these two thresholds depends on the temporal scale, the interaction of SLR with other environmental factors, and landscape metrics, which have not been fully accounted for before this study. We chose a representative marine-dominated estuary in the northern Gulf of Mexico, Grand Bay in Mississippi, to test the concept of SLR thresholds. We developed a mechanistic model to simulate wetland change and then derived the SLR thresholds for Grand Bay. The model results show that the threshold of SLR rate in Grand Bay is 11.9 mm/year for 2050, and it drops to 8.4 mm/year for 2100 using total wetland area as a landscape metric. The corresponding SLR acceleration rate thresholds are 3.02 × 10 -4  m/year 2 and 9.62 × 10 -5  m/year 2 for 2050 and 2100, respectively. The newly developed SLR acceleration rate threshold can help quantify the temporal lag before the rapid decline in wetland area becomes evident after the SLR rate threshold is exceeded, and cumulative SLR a wetland can adapt to under the SLR acceleration scenarios. Based on the thresholds, SLR that will adversely impact the coastal wetlands in Grand Bay by 2100 will fall within the likely range of SLR under a high warming scenario (RCP8.5), highlighting the need to avoid RCP8.5 to preserve these marshes.

Connecting Systems Model Design to Decision-Maker and Stakeholder Needs: Lessons from Louisiana's Coastal Master Plan

Science.gov (United States)

Fischbach, J. R.; Johnson, D.

2017-12-01

Louisiana's Comprehensive Master Plan for a Sustainable Coast is a 50-year plan designed to reduce flood risk and minimize land loss while allowing for the continued provision of economic and ecosystem services from this critical coastal region. Conceived in 2007 in response to hurricanes Katrina and Rita in 2005, the master plan is updated on a five-year planning cycle by the state's Coastal Protection and Restoration Authority (CPRA). Under the plan's middle-of-the-road (Medium) environmental scenario, the master plan is projected to reduce expected annual damage from storm surge flooding by approximately 65% relative to a future without action: from 5.3 billion to 2.2 billion in 2040, and from 12.1 billion to 3.7 billion in 2065. The Coastal Louisiana Risk Assessment model (CLARA) is used to estimate the risk reduction impacts of projects that have been considered for implementation as part of the plan. Evaluation of projects involves estimation of cost effectiveness in multiple future time periods and under a range of environmental uncertainties (e.g., the rates of sea level rise and land subsidence, changes in future hurricane intensity and frequency), operational uncertainties (e.g., system fragility), and economic uncertainties (e.g., patterns of population change and asset exposure). Between the 2012 and 2017 planning cycles, many improvements were made to the CLARA model. These included changes to the model's spatial resolution and definition of policy-relevant spatial units, an improved treatment of parametric uncertainty and uncertainty propagation between model components, the addition of a module to consider critical infrastructure exposure, and a new population growth model. CPRA also developed new scenarios for analysis in 2017 that were responsive to new scientific literature and to accommodate a new approach to modeling coastal morphology. In this talk, we discuss how CLARA has evolved over the 2012 and 2017 planning cycles in response to the needs

Development of a Bi-National Great Lakes Coastal Wetland and Land Use Map Using Three-Season PALSAR and Landsat Imagery

Directory of Open Access Journals (Sweden)

Laura Bourgeau-Chavez

2015-07-01

Full Text Available Methods using extensive field data and three-season Landsat TM and PALSAR imagery were developed to map wetland type and identify potential wetland stressors (i.e., adjacent land use for the United States and Canadian Laurentian coastal Great Lakes. The mapped area included the coastline to 10 km inland to capture the region hydrologically connected to the Great Lakes. Maps were developed in cooperation with the overarching Great Lakes Consortium plan to provide a comprehensive regional baseline map suitable for coastal wetland assessment and management by agencies at the local, tribal, state, and federal levels. The goal was to provide not only land use and land cover (LULC baseline data at moderate spatial resolution (20–30 m, but a repeatable methodology to monitor change into the future. The prime focus was on mapping wetland ecosystem types, such as emergent wetland and forested wetland, as well as to delineate wetland monocultures (Typha, Phragmites, Schoenoplectus and differentiate peatlands (fens and bogs from other wetland types. The overall accuracy for the coastal Great Lakes map of all five lake basins was 94%, with a range of 86% to 96% by individual lake basin (Huron, Ontario, Michigan, Erie and Superior.

Phosphorus storage and mobilization in coastal Phragmites wetlands: Influence of local-scale hydrodynamics

Science.gov (United States)

Karstens, Svenja; Buczko, Uwe; Glatzel, Stephan

2016-04-01

Coastal Phragmites wetlands are at the interface between terrestrial and aquatic ecosystems and are of paramount importance for nutrient regulation. They can act both as sinks and sources for phosphorus, depending on environmental conditions, sediment properties as well as on antecedent nutrient loading and sorption capacity of the sediments. The Darss-Zingst Bodden Chain is a shallow lagoon system at the German Baltic Sea coast with a long eutrophication history. It is lined almost at its entire length by reed wetlands. In order to elucidate under which conditions these wetlands act as sources or sinks for phosphorus, in-situ data of chemo-physical characteristics of water and sediment samples were combined with hydrodynamic measurements and laboratory experiments. Small-scale basin structures within the wetland serve as sinks for fine-grained particles rich in phosphorus, iron, manganese and organic matter. Without turbulent mixing the bottom water and the sediment surface lack replenishment of oxygen. During stagnant periods with low water level, low turbulence and thus low-oxygen conditions phosphorus from the sediments is released. But the sediments are capable of becoming sinks again once oxygen is resupplied. A thin oxic sediment surface layer rich in iron and manganese adsorbs phosphorus quickly. We demonstrate that sediments in coastal Phragmites wetlands can serve both as sources and sinks of soluble reactive phosphorus on a very short time-scale, depending on local-scale hydrodynamics and the state of the oxic-anoxic sediment interface.

Controls of Carbon Preservation in Coastal Wetlands of Texas: Mangrove vs. Saltmarsh Ecosystems

Science.gov (United States)

Sterne, A. M. E.; Louchouarn, P.; Norwood, M. J.; Kaiser, K.

2014-12-01

The estimated magnitude of the carbon (C) stocks contained in the first meter of US coastal wetland soils represents ~10% of the entire C stock in US soils (4 vs. 52 Pg, respectively). Because this stock extends to several meters below the surface for many coastal wetlands, it becomes paramount to understand the fate of C under ecosystem shifts, varying natural environmental constraints, and changing land use. In this project we analyze total hydrolysable carbohydrates, amino acids, phenols and stable isotopic data (δ13C) at two study sites located on the Texas coastline to investigate chemical compositions and the stage of decomposition in mangrove and marsh grass dominated wetlands. Carbohydrates are used as specific decomposition indicators of the polysaccharide component of wetland plants, whereas amino acids are used to identify the contribution of microbial biomass, and acid/aldehyde ratios of syringyl (S) and vanillyl (V) phenols (Ac/AlS,V) follow the decomposition of lignin. Preliminary results show carbohydrates account for 30-50 % of organic carbon in plant litter and surface sediments at both sites. Sharp declines of carbohydrate yields with depth occur parallel to increasing Ac/AlS,V ratios indicating substantial decomposition of both the polysaccharide and lignin components of litter detritus. Ecological differences (between marsh grass and mangrove dominated wetlands) are discussed to better constrain the role of litter biochemistry and ecological shifts on C preservation in these anoxic environments.

Are Predators Limiting Zebra Mussel Colonization of Unionid Mussels in Great Lake Coastal Wetlands?

Science.gov (United States)

de Szalay, F. A.; Bowers, R.

2005-05-01

Although many native mollusc populations have been eliminated in the Laurentian Great Lakes by the exotic zebra mussel, recent surveys have found abundant unionid (Bivalvia: Unionidae) populations in some coastal wetlands. Unionid burrowing in soft sediments and predation by fish have been shown to reduce numbers of attached zebra mussels, and we tested these factors in a Lake Erie coastal wetland. In 2002, we held live unionids (Leptodea fragilis, Quadrula quadrula) and Pyganodon grandis shells in exclosures with wire mesh bottoms that were buried to sediment depths of either 5, 10, or 20 cm. After 2 months, numbers of attached dreissenids on unionids were significantly higher inside all exclosure treatments than outside exclosures. This indicated that either unionid burrowing was prevented in all sediment depth treatments or molluscivores were excluded by exclosures. In 2004, we measured dreissenid colonization on Q. quadrula and PVC plates in bottomless exclosures with different mesh sizes. After 6 months, dreissenid numbers on PVC plates and on Q. quadrula in 2.5 cm X 2.5 cm and 5 cm X 10 cm mesh exclosures were significantly higher than in open exclosures. These data suggest that molluscivores are important in limiting dreissenids in Great Lake coastal wetlands.

Preliminary Evaluation of Critical Wave Energy Thresholds at Natural and Created Coastal Wetlands

National Research Council Canada - National Science Library

Shafer, Deborah

2003-01-01

This technical note presents an evaluation of the wave climate at eight natural and created coastal wetland sites in an effort to identify the existence of critical wave energy thresholds for long-term marsh stability...

Lake Superior Coastal Wetland Fish Assemblages and Habitat Conditions in Relation to Watershed Connectivity and Landcover

Science.gov (United States)

The role of the coastal margin and the watershed context in defining the ecology of even very large lakes is increasingly being recognized and examined. Coastal wetlands are both important contributors to the biodiversity and productivity of large lakes and important mediators o...

WETLAND CHANGE DETECTION IN PROTECTED AND UNPROTECTED INDUS COASTAL AND INLAND DELTA

Directory of Open Access Journals (Sweden)

M. H. Ali Baig

2017-09-01

Full Text Available Worth of wetland sites lies in their ecological importance. They enhance ecosystem via provision of ecological services like improving water quality, groundwater infiltration, flood risk reduction and biodiversity regulation. Like other parts of the world Pakistan is also facing wetlands degradation. Ecological and economic significance of wetlands was recognized officially in 1971 as Pakistan became signatory of Ramsar wetland convention. Wetlands provide habitat to species of ecological and economic importance. Despite being recognized for international importance, Ramsar figures state that almost half of Pakistan’s wetlands are at moderate or prominent level threat. Wetlands ecosystems are deteriorating at a rapid rate, if uncontrolled this trend may lead to substantial losses. Therefore, management of these resources demands regular monitoring. Present study is dedicated to assessing levels of change overtime in three distinct types of wetlands in Pakistan i.e. Indus delta a coastal wetland, Uchhali complex an inland wetland which are both protected sites while another site Nurri Lagoon which is not sheltered under any category of protected areas. Remotely sensed data has remarkable applications in change detection. Multitemporal Landsat images were used to map changes occurring from 2006 to 2016. Results reveal that wetland area has considerably decreased for all types. Both protected sites have experienced degradation though impact is comparatively lesser than unprotected Nurri lagoon. Significance of protection strategies cannot be denied, it is recommended that mere declaration of a site protected area is not sufficient. It is equally important to control non-point pollutants and ensuring the compliance of conservation strategy.

Wetland Change Detection in Protected and Unprotected Indus Coastal and Inland Delta

Science.gov (United States)

Baig, M. H. Ali; Sultan, M.; Riaz Khan, M.; Zhang, L.; Kozlova, M.; Malik, N. Abbas; Wang, S.

2017-09-01

Worth of wetland sites lies in their ecological importance. They enhance ecosystem via provision of ecological services like improving water quality, groundwater infiltration, flood risk reduction and biodiversity regulation. Like other parts of the world Pakistan is also facing wetlands degradation. Ecological and economic significance of wetlands was recognized officially in 1971 as Pakistan became signatory of Ramsar wetland convention. Wetlands provide habitat to species of ecological and economic importance. Despite being recognized for international importance, Ramsar figures state that almost half of Pakistan's wetlands are at moderate or prominent level threat. Wetlands ecosystems are deteriorating at a rapid rate, if uncontrolled this trend may lead to substantial losses. Therefore, management of these resources demands regular monitoring. Present study is dedicated to assessing levels of change overtime in three distinct types of wetlands in Pakistan i.e. Indus delta a coastal wetland, Uchhali complex an inland wetland which are both protected sites while another site Nurri Lagoon which is not sheltered under any category of protected areas. Remotely sensed data has remarkable applications in change detection. Multitemporal Landsat images were used to map changes occurring from 2006 to 2016. Results reveal that wetland area has considerably decreased for all types. Both protected sites have experienced degradation though impact is comparatively lesser than unprotected Nurri lagoon. Significance of protection strategies cannot be denied, it is recommended that mere declaration of a site protected area is not sufficient. It is equally important to control non-point pollutants and ensuring the compliance of conservation strategy.

Rising tides, rising gates: The complex ecogeomorphic response of coastal wetlands to sea-level rise and human interventions

Science.gov (United States)

Sandi, Steven G.; Rodríguez, José F.; Saintilan, Neil; Riccardi, Gerardo; Saco, Patricia M.

2018-04-01

Coastal wetlands are vulnerable to submergence due to sea-level rise, as shown by predictions of up to 80% of global wetland loss by the end of the century. Coastal wetlands with mixed mangrove-saltmarsh vegetation are particularly vulnerable because sea-level rise can promote mangrove encroachment on saltmarsh, reducing overall wetland biodiversity. Here we use an ecogeomorphic framework that incorporates hydrodynamic effects, mangrove-saltmarsh dynamics, and soil accretion processes to assess the effects of control structures on wetland evolution. Migration and accretion patterns of mangrove and saltmarsh are heavily dependent on topography and control structures. We find that current management practices that incorporate a fixed gate for the control of mangrove encroachment are useful initially, but soon become ineffective due to sea-level rise. Raising the gate, to counteract the effects of sea level rise and promote suitable hydrodynamic conditions, excludes mangrove and maintains saltmarsh over the entire simulation period of 100 years

Importance of Small Isolated Wetlands for Herpetofaunal Diversity in Managed, Young Growth Forests in the Coastal Plain of South Carolina

International Nuclear Information System (INIS)

Russell, K.R.; Guynn, D.C. Jr.; Hanlin, H.G.

2002-01-01

Assessment and comparison of richness, abundance and difference of herpetofauna at five small isolated wetlands located within a commercial forest landscape in the South Carolina Coastal Plain. Data indicates small isolated wetlands are focal points of herpetofaunal richness and abundance in managed coastal plain forest and contribute more to regional biodiversity than is implied by their small size or ephemeral hydrology

HYPERSPECTRAL REMOTE SENSING, GPS, AND GIS APPLICATIONS IN OPPORTUNISTIC PLANT SPECIES MONITORING OF GREAT LAKES COASTAL WETLANDS

Science.gov (United States)

Coastal wetlands of the Laurentian Great Lakes (LGL) are among the most fragmented and disturbed ecosystems of the world, with a long history of human-induced disturbance. LGL wetlands have undergone losses in the biological diversity that coincides with an increase in the presen...

Jiangsu coastal highland reclamation and its wetland ecological construction-a case analysis of the Tiaozini reclamation project

Science.gov (United States)

Yu, Meixiu; Xu, Xianghong

2017-04-01

Reclamation is one potential solution for the increasing demand of new land for living and development. In past centuries, many coastal countries, such as the Netherlands, UK, Japan, South Korea and Singapore, had exploited extensively sea enclosing and reclamation fordefense against storm surges,agricultural and industrial development, as well as for coastal city expansion along the coast. China has continuously reclaimed coastal sea areas from the 1950s. With rapid economic development and increasing population in coastal areas during recent decades, reclamation has been regarded as an effective measure to resolve the land shortage as cities and industries expand, particularly in South-East coastal areas. Jiangsu province, located in East China, has a similar amount of land territory area to the Netherlands, however, its population is almost fivefold instead. Since its coastal area generates large amounts of tidal flat resources due to its unique hydrodynamic and geomorphic conditions, coastal reclamation plays a vital role in guaranteeing the food security for the Jiangsu Province or even the whole nation. The Tiaozini Reclamation Project (TRP), located between N32.720°-32.882°, E120.894°-120.969°, in Jianggang county of Jiangsu coastal region, with an area of 6,746ha, was reclaimed along the prograding muddy silt coast in 2012. It should be noted that the TRP was reclaimed from theoretical bathymetrical datum of about 4.6m. It is estimated that the shoreline moves towards the sea at a rate of 100m/year and the tidal flat raises at a rate of 5 10 cm/year respectively because of the external tidal flat being continually prograding and drying. After finishing reclamation,the TRP develops with nature: for the dried tidal flat high land,developing ecological agriculture after integrated soil improvement with reducing salt and cultivating fertilizer; for the drying tidal flat,developing ecological fishery by inceasing artificial wetland area; for lower tidal flat

U.S. Pacific coastal wetland resilience and vulnerability to sea-level rise

Science.gov (United States)

Thorne, Karen M.; MacDonald, Glen M.; Guntenspergen, Glenn R.; Ambrose, Richard F.; Buffington, Kevin J.; Dugger, Bruce D.; Freeman, Chase; Janousek, Christopher; Brown, Lauren N.; Rosencranz, Jordan A.; Homquist, James; Smol, John P.; Hargan, Kathryn; Takekawa, John Y.

2018-01-01

We used a first-of-its-kind comprehensive scenario approach to evaluate both the vertical and horizontal response of tidal wetlands to projected changes in the rate of sea-level rise (SLR) across 14 estuaries along the Pacific coast of the continental United States. Throughout the U.S. Pacific region, we found that tidal wetlands are highly vulnerable to end-of-century submergence, with resulting extensive loss of habitat. Using higher-range SLR scenarios, all high and middle marsh habitats were lost, with 83% of current tidal wetlands transitioning to unvegetated habitats by 2110. The wetland area lost was greater in California and Oregon (100%) but still severe in Washington, with 68% submerged by the end of the century. The only wetland habitat remaining at the end of the century was low marsh under higher-range SLR rates. Tidal wetland loss was also likely under more conservative SLR scenarios, including loss of 95% of high marsh and 60% of middle marsh habitats by the end of the century. Horizontal migration of most wetlands was constrained by coastal development or steep topography, with just two wetland sites having sufficient upland space for migration and the possibility for nearly 1:1 replacement, making SLR threats particularly high in this region and generally undocumented. With low vertical accretion rates and little upland migration space, Pacific coast tidal wetlands are at imminent risk of submergence with projected rates of rapid SLR.

Effects of salinity and flooding on post-hurricane regeneration potential in coastal wetland vegetation.

Science.gov (United States)

Middleton, Beth A

2016-08-01

The nature of regeneration dynamics after hurricane flooding and salinity intrusion may play an important role in shaping coastal vegetation patterns. The regeneration potentials of coastal species, types and gradients (wetland types from seaward to landward) were studied on the Delmarva Peninsula after Hurricane Sandy using seed bank assays to examine responses to various water regimes (unflooded and flooded to 8 cm) and salinity levels (0, 1, and 5 ppt). Seed bank responses to treatments were compared using a generalized linear models approach. Species relationships to treatment and geographical variables were explored using nonmetric multidimensional scaling. Flooding and salinity treatments affected species richness even at low salinity levels (1 and 5 ppt). Maritime forest was especially intolerant of salinity intrusion so that species richness was much higher in unflooded and low salinity conditions, despite the proximity of maritime forest to saltmarsh along the coastal gradient. Other vegetation types were also affected, with potential regeneration of these species affected in various ways by flooding and salinity, suggesting relationships to post-hurricane environment and geographic position. Seed germination and subsequent seedling growth in coastal wetlands may in some cases be affected by salinity intrusion events even at low salinity levels (1 and 5 ppt). These results indicate that the potential is great for hurricanes to shift vegetation type in sensitive wetland types (e.g., maritime forest) if post-hurricane environments do not support the regeneration of extent vegetation. This article is a U.S. Government work and is in the public domain in the USA. © Botanical Society of America (outside the USA) 2016.

Eco-morphological Real-time Forecasting tool to predict hydrodynamic, sediment and nutrient dynamic in Coastal Louisiana

Science.gov (United States)

Messina, F.; Meselhe, E. A.; Buckman, L.; Twight, D.

2017-12-01

Louisiana coastal zone is one of the most productive and dynamic eco-geomorphic systems in the world. This unique natural environment has been alternated by human activities and natural processes such as sea level rise, subsidence, dredging of canals for oil and gas production, the Mississippi River levees which don't allow the natural river sediment. As a result of these alterations land loss, erosion and flood risk are becoming real issues for Louisiana. Costal authorities have been studying the benefits and effects of several restoration projects, e.g. freshwater and sediment diversions. The protection of communities, wildlife and of the unique environments is a high priority in this region. The Water Institute of the Gulf, together with Deltares, has developed a forecasting and information system for a pilot location in Coastal Louisiana, specifically for Barataria Bay and Breton Sound Basins in the Mississippi River Deltaic Plain. The system provides a 7-day forecast of water level, salinity, and temperature, under atmospheric and coastal forecasted conditions, such as freshwater riverine inflow, rainfall, evaporation, wind, and tide. The system also forecasts nutrient distribution (e.g., Chla and dissolved oxygen) and sediment transport. The Flood Early Warning System FEWS is used as a platform to import multivariate data from several sources, use them to monitor the pilot location and to provide boundary conditions to the model. A hindcast model is applied to compare the model results to the observed data, and to provide the initial condition to the forecast model. This system represents a unique tool which provides valuable information regarding the overall conditions of the basins. It offers the opportunity to adaptively manage existing and planned diversions to meet certain salinity and water level targets or thresholds while maximizing land-building goals. Moreover, water quality predictions provide valuable information on the current ecological

Effects of Land Use Changes on the Ecosystem Service Values of Coastal Wetlands

Science.gov (United States)

Camacho-Valdez, Vera; Ruiz-Luna, Arturo; Ghermandi, Andrea; Berlanga-Robles, César A.; Nunes, Paulo A. L. D.

2014-10-01

Changes in the coastal landscape of Southern Sinaloa (Mexico), between 2000 and 2010, were analyzed to relate spatial variations in wetlands extent with the provision and economic value of the ecosystem services (ES). Remote sensing techniques applied to Landsat TM imagery were used to evaluate land use/land cover changes while the value transfer method was used to assess the value of ES by land cover category. Five wetland types and other four land covers were found as representative of the coastal landscape. Findings reveal a 14 % decrease in the saltmarsh/forested mangrove area and a 12 % increase in the area of shrimp pond aquaculture (artificial wetland) during the study period. ES valuation shows that the total value flow increased by 9 % from 215 to 233 million (2007 USD) during the 10-year period. This increase is explained as result of the high value worldwide assigned to saltmarsh. We recognize limitations in the transfer-based approach in quantifying and mapping ES values in the region, but this method provides with value estimates spatially defined, and also provides some guidance in the preliminary screening of policies and projected development in the context of data-scarce regions.

Assessment of coastal wetland resources of central west coast, India, using LANDSAT data

Digital Repository Service at National Institute of Oceanography (India)

Jagtap, T.G.; Naik, S.; Nagle, V.L.

The part of central west coast (Maharashtra and Goa) of India has been classified and quantified for coastal wetlands using LANDSAT data of 1985-86. The classification accuracy of the maps and area estimates achieved was 84% at 90% confidence level...

Improved coastal wetland mapping using very-high 2-meter spatial resolution imagery

Science.gov (United States)

McCarthy, Matthew J.; Merton, Elizabeth J.; Muller-Karger, Frank E.

2015-08-01

Accurate wetland maps are a fundamental requirement for land use management and for wetland restoration planning. Several wetland map products are available today; most of them based on remote sensing images, but their different data sources and mapping methods lead to substantially different estimations of wetland location and extent. We used two very high-resolution (2 m) WorldView-2 satellite images and one (30 m) Landsat 8 Operational Land Imager (OLI) image to assess wetland coverage in two coastal areas of Tampa Bay (Florida): Fort De Soto State Park and Weedon Island Preserve. An initial unsupervised classification derived from WorldView-2 was more accurate at identifying wetlands based on ground truth data collected in the field than the classification derived from Landsat 8 OLI (82% vs. 46% accuracy). The WorldView-2 data was then used to define the parameters of a simple and efficient decision tree with four nodes for a more exacting classification. The criteria for the decision tree were derived by extracting radiance spectra at 1500 separate pixels from the WorldView-2 data within field-validated regions. Results for both study areas showed high accuracy in both wetland (82% at Fort De Soto State Park, and 94% at Weedon Island Preserve) and non-wetland vegetation classes (90% and 83%, respectively). Historical, published land-use maps overestimate wetland surface cover by factors of 2-10 in the study areas. The proposed methods improve speed and efficiency of wetland map production, allow semi-annual monitoring through repeat satellite passes, and improve the accuracy and precision with which wetlands are identified.

Effects of salinity and particle concentration on sediment hydrodynamics and critical bed-shear-stress for erosion of fine grained sediments used in wetland restoration projects

Science.gov (United States)

Ghose-Hajra, M.; McCorquodale, A.; Mattson, G.; Jerolleman, D.; Filostrat, J.

2015-03-01

Sea-level rise, the increasing number and intensity of storms, oil and groundwater extraction, and coastal land subsidence are putting people and property at risk along Louisiana's coast, with major implications for human safety and economic health of coastal areas. A major goal towards re-establishing a healthy and sustainable coastal ecosystem has been to rebuild Louisiana's disappearing wetlands with fine grained sediments that are dredged or diverted from nearby rivers, channels and lakes to build land in open water areas. A thorough geo-hydrodynamic characterization of the deposited sediments is important in the correct design and a more realistic outcome assessment of the long-term performance measures for ongoing coastal restoration projects. This paper evaluates the effects of salinity and solid particle concentration on the re-suspension characteristics of fine-grained dredged sediments obtained from multiple geographic locations along the Gulf coast. The critical bed-shear-stress for erosion has been evaluated as a function of sedimentation time. The sediment hydrodynamic properties obtained from the laboratory testing were used in a numerical coastal sediment distribution model to aid in evaluating sediment diversions from the Mississippi River into Breton Sound and Barataria Bay.

Pipeline corridors through wetlands - impacts on plant communities: Bayou Pointe Aux Chenes, Terrebonne Parish, Louisiana. Topical report, August 1991--April 1994

Energy Technology Data Exchange (ETDEWEB)

Van Dyke, G.D.; Shem, L.M.; Zimmerman, R.E.

1994-12-01

The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipelines on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and night- of-way management practices. This report presents the results of a survey conducted on August 22, 1991, in an emergent intertidal estuarine wetland in Terrebonne Parish, Louisiana. The site includes three pipelines installed between 1958 and 1969. Vegetation within the site comprises three native tidal marsh grasses: Spartina alterniflora, Spartina patens, and Distichlis spicata. All three species occurred over the pipelines, within the right-of-way and in both natural areas. Vegetative differences attributable to the installation or presence of the pipelines were not obvious over the pipelines or in the habitat east of the pipelines. However, because of the presence of a canal west of the 1969 pipeline, vegetation was less abundant in that area, and D. spicata was absent from all but the most distant plots of the transacts. Data obtained in the study indicate that when rights-of-way through brackish marsh are restored to their original elevations, they are revegetated with native vegetation similar to that in surrounding areas.

Combined influence of sedimentation and vegetation on the soil carbon stocks of a coastal wetland in the Changjiang estuary

Science.gov (United States)

Zhang, Tianyu; Chen, Huaipu; Cao, Haobing; Ge, Zhenming; Zhang, Liquan

2017-07-01

Coastal wetlands play an important role in the global carbon cycle. Large quantities of sediment deposited in the Changjiang (Yangtze) estuary by the Changjiang River promote the propagation of coastal wetlands, the expansion of saltmarsh vegetation, and carbon sequestration. In this study, using the Chongming Dongtan Wetland in the Changjiang estuary as the study area, the spatial and temporal distribution of soil organic carbon (SOC) stocks and the influences of sedimentation and vegetation on the SOC stocks of the coastal wetland were examined in 2013. There was sediment accretion in the northern and middle areas of the wetland and in the Phragmites australis marsh in the southern area, and sediment erosion in the Scirpus mariqueter marsh and the bare mudflat in the southern area. More SOC accumulated in sediments of the vegetated marsh than in the bare mudflat. The total organic carbon (TOC) stocks increased in the above-ground biomass from spring to autumn and decreased in winter; in the below-ground biomass, they gradually increased from spring to winter. The TOC stocks were higher in the below-ground biomass than in the above-ground biomass in the P. australis and Spartina alterniflora marshes, but were lower in the below-ground biomass in S. mariqueter marsh. Stocks of SOC showed temporal variation and increased gradually in all transects from spring to winter. The SOC stocks tended to decrease from the high marsh down to the bare mudflat along the three transects in the order: P. australis marsh > S. alterniflora marsh > S. mariqueter marsh > bare mudflat. The SOC stocks of the same vegetation type were higher in the northern and middle transects than in the southern transect. These results suggest that interactions between sedimentation and vegetation regulate the SOC stocks in the coastal wetland in the Changjiang estuary.

Using Advances in Research on Louisiana Coastal Restoration and Protection to Develop Undergraduate Hydrology Education Experiences Delivered via a Web Interface

Science.gov (United States)

Bodin, M.; Habib, E. H.; Meselhe, E. A.; Visser, J.; Chimmula, S.

2014-12-01

Utilizing advances in hydrologic research and technology, learning modules can be developed to deliver visual, case-based, data and simulation driven educational experiences. This paper focuses on the development of web modules based on case studies in Coastal Louisiana, one of three ecosystems that comprise an ongoing hydrology education online system called HydroViz. The Chenier Plain ecosystem in Coastal Louisiana provides an abundance of concepts and scenarios appropriate for use in many undergraduate water resource and hydrology curricula. The modules rely on a set of hydrologic data collected within the Chenier Plain along with inputs and outputs of eco-hydrology and vegetation-change simulation models that were developed to analyze different restoration and protection projects within the 2012 Louisiana Costal Master Plan. The modules begin by investigating the basic features of the basin and it hydrologic characteristics. The eco-hydrology model is then introduced along with its governing equations, numerical solution scheme and how it represents the study domain. Concepts on water budget in a coastal basin are then introduced using the simulation model inputs, outputs and boundary conditions. The complex relationships between salinity, water level and vegetation changes are then investigated through the use of the simulation models and associated field data. Other student activities focus on using the simulation models to evaluate tradeoffs and impacts of actual restoration and protection projects that were proposed as part of 2012 Louisiana Master Plan. The hands-on learning activities stimulate student learning of hydrologic and water management concepts by providing real-world context and opportunity to build fundamental knowledge as well as practical skills. The modules are delivered through a carefully designed user interface using open source and free technologies which enable wide dissemination and encourage adaptation by others.

Investigating The Relationship Between Structural Geology and Wetland Loss Near Golden Meadow, Louisiana By Utilizing 3D Seismic Reflection and Well Log Data

Science.gov (United States)

Johnston, A. S.; Zhang, R.; Gottardi, R.; Dawers, N. H.

2017-12-01

Wetland loss is one of the greatest environmental and economic threats in the deltaic plain of the Gulf Coast. This loss is controlled by subsidence, sea level rise, decreased sediment supply rates, movement along normal faults, salt tectonics, fluid extraction related to oil, gas and water exploration, and compaction. However, the interplay and feedback between these different processes are still poorly understood. In this study, we investigate the role of active faulting and salt tectonics on wetland loss in an area located between Golden Meadow and Leeville, Louisiana. Using industry 3D seismic and well log data, we investigate key segments of the Golden Meadow fault zone and map shallow faults that overlie the Leeville salt dome, to compare those fault planes with areas of wetland loss and subsidence. Faults were mapped to a depth of 1200 m, and well logs were tied to the upper 180 m of the seismic data to make accurate projections of the faults to the surface. Preliminary results highlight a graben structure south of a segment of the Golden Meadow fault. Well log and published data from shallow borings reveal a thicker Holocene accumulation at the center of the graben, up to 45 m than on the flanks of the graben. The location of this graben spatially correlates with Catfish Lake, and part of it overlies salt adjacent to the main fault surface. Bayou Lafourche, the main distributary channel of the Lafourche lobe of the Mississippi River delta complex, appears to have its path controlled by faults. Bayou Lafourche changes orientation and flows parallel to, and on the downthrown side of, two radial faults associated with the Leeville salt dome. These preliminary results indicate that there is a relationship between surface geomorphology and subsurface structures that, at least in part, exert a control on wetland loss in southern Louisiana.

The coupling of bay hydrodynamics with sediment supply and micro-tidal wetland stability under high rates of relative sea level rise

Science.gov (United States)

Wang, J.; Xu, K.; Restreppo, G. A.; Bentley, S. J.; Meng, X.; Zhang, X.

2017-12-01

Due to global sea level rise, local subsidence and sediment deficit, the Mississippi River (MR) deltaic plain has lost a total of 25% of coastal Louisiana's wetlands during the last century, leading to huge losses of ecological services, economic and social crises. Ecosystem-based restoration strategies which rely on coastal system processes and feedbacks are urgently needed. Understanding linkages between estuarine and coastal systems and the adjacent marshlands will help the designing strategies. To investigate bay hydrodynamics and its impacts on the adjacent micro-tidal wetland stability, hourly measurements of wave, tidal current, and benthic sediment concentration in summer, winter, and spring of 2015-2016 were conducted in Fourleague Bay, Louisiana, USA. The bay-marsh system has been stable for almost 80 years under high relative sea level rising rate, which is 11 km southeast of the Atchafalaya River mouth, with a water depth of 1-3 m. High-temporal resolution data indicate that benthic sediment resuspension is mainly caused by wind-driven waves with a dominant periodicity of 4.8 d. The sediment flux reaches 28 g·m-1·s-1 per unit depth in cm during the events. Net sediment transport is northwestward in summer, and southeastward in winter and spring. Sediment flux available for surrounding marsh varies from 0-500 g·m-1·s-1. An optimal inundation depth of 50 cm is estimated by the equilibrium wetland elevation change model under high relative sea level rising rate of 1.57 cm·yr-1. Seasonal variations of river discharge and wind direction (particularly speeds >3 m·s-1) greatly impact potential sediment contribution from bay to the surrounding wetlands. Three sediment transport regimes are concluded based on the seasonal variations of river discharge and wind direction: the `bypassing' season, the resuspension-accumulation season, and the combined `bypassing' and resuspension-accumulation season. The bay hydrodynamic processes and their impacts on the

Sources of atmospheric methane from coastal marine wetlands

International Nuclear Information System (INIS)

Harriss, R.C.; Sebacher, D.I.; Bartlett, K.B.; Bartlett, D.S.

1982-01-01

Biological methanogenesis in wetlands is believed to be one of the major sources of global tropospheric methane. The present paper reports measurements of methane distribution in the soils, sediments, water and vegetation of coastal marine wetlands. Measurements, carried out in the salt marshes Bay Tree Creek in Virginia and Panacea in northwest Florida, reveal methane concentrations in soils and sediments to vary with depth below the surface and with soil temperature. The fluxes of methane from marsh soils to the atmosphere at the soil-air interface are estimated to range from -0.00067 g CH 4 /sq m per day (methane sink) to 0.024 g CH 4 /sq m per day, with an average value of 0.0066 g CH 4 /sq m per day. Data also demonstrate the important role of tidal waters percolating through marsh soils in removing methane from the soils and releasing it to the atmosphere. The information obtained, together with previous studies, provides a framework for the design of a program based on in situ and remote sensing measurements to study the global methane cycle

Development and Application of a Cohesive Sediment Transport Model in Coastal Louisiana

Science.gov (United States)

Sorourian, S.; Nistor, I.

2017-12-01

The Louisiana coast has suffered from rapid land loss due to the combined effects of increasing the rate of eustatic sea level rise, insufficient riverine sediment input and subsidence. The sediment in this region is dominated by cohesive sediments (up to 80% of clay). This study presents a new model for calculating suspended sediment concentration (SSC) of cohesive sediments. Several new concepts are incorporated into the proposed model, which is capable of estimating the spatial and temporal variation in the concentration of cohesive sediment. First, the model incorporates the effect of electrochemical forces between cohesive sediment particles. Second, the wave friction factor is expressed in terms of the median particle size diameter in order to enhance the accuracy of the estimation of bed shear stress. Third, the erosion rate of cohesive sediments is also expressed in time-dependent form. Simulated SSC profiles are compared with field data collected from Vermilion Bay, Louisiana. The results of the proposed model agree well with the experimental data, as soon as steady state condition is achieved. The results of the new numerical models provide a better estimation of the suspended sediment concentration profile compared to the initial model developed by Mehta and Li, 2003. Among the proposed developments, the formulation of a time-dependent erosion rate shows the most accurate results. Coupling of present model with the Finite-Volume, primitive equation Community Ocean Model (FVCOM) would shed light on the fate of fine-grained sediments in order to increase overall retention and restoration of the Louisiana coastal plain.

Lafourche Parish Coastal Zone Curriculum Resource Unit. Bulletin 1834.

Science.gov (United States)

Daigle, Bobby; And Others

The Louisiana coastal zone is a unique geographic feature. Soil carried by the Mississippi River has been deposited in Louisiana for the last 6,000 years to form the coastal area. All natural features in coastal Louisiana relate to materials and processes associated with the emptying of the Mississippi River into the Gulf of Mexico. The…

AN ECOLOGICAL ASSESSMENT OF INVASIVE AND AGRESSIVE PLANT SPECIES IN COASTAL WETLANDS OF THE LAURENTIAN GREAT LAKES: A COMBINED FIELD BASED AND REMOTE SENSING APPROACH

Science.gov (United States)

The aquatic plant communities within coastal wetlands of the Laurentian Great Lakes are among the most biologically diverse and productive systems of the world. Coastal wetlands have been especially impacted by landscape conversion and have undergone a marked decline in plant com...

Monitoring Environmental Recovery at Terminated Produced Water Discharge Sites in Coastal Louisiana Waters

Energy Technology Data Exchange (ETDEWEB)

Continental Shelf Associates, Inc.

1999-08-16

This report presents the results of a study of terminated produced water discharge sites in the coastal waters of Louisiana. Environmental recovery at the sites is documented by comparing pre-termination and post-termination (six months and one year) data. Produced water, sediments, and sediment interstitial water samples were analyzed for radionuclides, metals, and hydrocarbons. Benthic infauna were identified from samples collected in the vicinity of the discharge and reference sites. Radium isotope activities were determined in fish and crustacean samples. In addition, an environmental risk assessment is made on the basis of the concentrations of metals and hydrocarbons determined in the samples.

Pipeline corridors through wetlands - impacts on plant communities: Bayou Grand Cane, De Soto Parish, Louisiana. Topical report, August 1991--July 1993

Energy Technology Data Exchange (ETDEWEB)

Shem, L.M.; Zimmerman, R.E.; Hayes, D. [Argonne National Lab., IL (United States); Van Dyke, G.D. [Argonne National Lab., IL (United States)]|[Trinity Christian College, Palos Heights, IL (United States)

1994-12-01

The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipeline on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and night of-way (ROW) management practices. This report presents the results of a survey conducted over the period of August 12-13, 1991, at the Bayou Grand Cane crossing in De Soto Parish, Louisiana, where a pipeline constructed three years prior to the survey crosses the bayou through mature bottomland hardwoods. The sit was not seeded or fertilized after construction activities. At the time of sampling, a dense herb stratum (composed of mostly native species) covered the 20-m-wide ROW, except within drainage channels. As a result of the creation of the ROW, new habitat was created, plant diversity increased, and forest habitat became fragmented. The ROW must be maintained at an early stage of succession to allow access to the pipeline however, impacts to the wetland were minimized by decreasing the width of the ROW to 20 m and recreating the drainage channels across the ROW. The canopy trees on the ROW`s edge shaded part of the ROW, which helped to minimize the effects of the ROW.

Changes in Landscape Pattern of Wetland around Hangzhou Bay

Science.gov (United States)

Lin, Wenpeng; Li, Yuan; Xu, Dan; Zeng, Ying

2018-04-01

Hangzhou Bay is an important estuarial coastal wetland, which offers a large number of land and ecological resources. It plays a significant role in the sustainable development of resources, environment and economy. In this paper, based on the remote sensing images in 1996, 2005 and 2013, we extracted the coastal wetland data and analyzed the wetland landscape pattern of the Hangzhou Bay in the past 20 years. The results show that: (1) the area of coastal wetland is heading downwards in the recent decades. Paddy field and the coastal wetland diminish greatly. (2) the single dynamic degree of wetland of the Hangzhou Bay displays that paddy fields and coastal wetlands are shrinking, but lakes, reservoirs and ponds are constantly expanding. (3) the wetland landscape pattern index shows that total patch area of the coastal wetland and paddy fields have gradually diminished. The Shannon diversity index, the Shannon evenness index as well as the landscape separation index of the coastal wetlands in the Hangzhou Bay increase steadily. The landscape pattern in the study area has shown a trend of high fragmentation, dominance decreases, but some dominant landscape still exist in this region. (4) Urbanization and natural factors lead to the reduction of wetland area. Besides the pressure of population is a major threat to the wetland. The study will provide scientific basis for long-term planning for this region.

Diversity and composition of sediment bacteria in subtropical coastal wetlands of North Stradbroke Island, Queensland, Australia

Science.gov (United States)

Chuvochina, Maria; Sampayo, Eugenia; Welti, Nina; Hayes, Matthew; Lu, Yang; Lovelock, Catherine; Lockington, David

2013-04-01

Coastal wetlands provide a wide variety of important ecosystem services but continue to suffer disturbance, degradation and deforestation. Sediment bacteria are responsible for major nutrient transformation and recycling in these ecosystems. Insight into microbial community composition and the factors that determine them may improve our understanding of biogeochemical processes, food web dynamics, biodegradation processes and, thus, help to develop the management strategies for preserving the ecosystem health and services. Characterizing shifts in community taxa along environmental gradients has been shown to provide a useful tool for determining the major drivers affecting community structure and function. North Stradbroke Island (NSI) in Southern Queensland presents considerable habitat diversity including variety of groundwater dependent ecosystems such as lakes, swamps, sedge-like salt marshes and mangroves. Ecological responses of continuous groundwater extraction for municipal purposes and sand mining operations on NSI are still need to be assessed in order to protect its unique environment. Changes in coastal hydrology due to either climate change or human activity may directly affect microbial populations and, thus, biogeochemical cycles of nutrients. These may result in altering/losing some ecosystem services provided by coastal wetlands. In this study we examine microbial diversity and determine environmental controls on bacterial community structure along a natural transition from freshwater forested wetland (melaleuca woodland), sedge-like salt marsh and into mangroves located at NSI. The study area is characterized by significant groundwater flow, nutrient limitation and sharp transition from one ecosystem type to another. Sediment cores (0-5 cm and 20-25 cm depth) were collected from three representative sites of each zone (mangroves - salt marsh - freshwater wetland) along the salinity gradient in August 2012. Subsamples were set aside for use in

Biodiversity impacts from salinity increase in a coastal wetland.

Science.gov (United States)

Amores, Maria José; Verones, Francesca; Raptis, Catherine; Juraske, Ronnie; Pfister, Stephan; Stoessel, Franziska; Antón, Assumpció; Castells, Francesc; Hellweg, Stefanie

2013-06-18

A Life Cycle Impact Assessment method was developed to evaluate the environmental impact associated with salinity on biodiversity in a Spanish coastal wetland. The developed characterization factor consists of a fate and an effect factor and equals 3.16 × 10(-1) ± 1.84 × 10(-1) PAF · m(3) · yr · m(-3) (PAF: Potentially Affected Fraction of species) indicating a "potential loss of 0.32 m(3) ecosystem" for a water consumption rate of 1 m(3) · yr(-1). As a result of groundwater consumption with a rate of 1 m(3) · yr(-1), the PAF in the lost cubic meter of ecosystem equals 0.05, which has been proposed as the maximum tolerable effect to keep the ecosystem intact. The fate factor was calculated from seasonal water balances of the wetland Albufera de Adra. The effect factor was obtained from the fitted curve of the potentially affected fraction of native wetland species due to salinity and can be applied to other wetlands with similar species composition. In order to test the applicability of the characterization factor, an assessment of water consumption of greenhouse crops in the area was conducted as a case study. Results converted into ecosystem quality damage using the ReCiPe method were compared to other categories. While tomatoes are responsible for up to 30% of the impact of increased salinity due to water consumption on ecosystem quality in the studied area, melons have the largest impact per tonne produced.

The contrasting effects of nutrient enrichment on growth, biomass allocation and decomposition of plant tissue in coastal wetlands

NARCIS (Netherlands)

Hayes, Matthew A.; Jesse, Amber; Tabet, Basam; Reef, Ruth; Keuskamp, Joost A.; Lovelock, Catherine E.

2017-01-01

Eutrophication of coastal waters can have consequences for the growth, function and soil processes of coastal wetlands. Our aims were to assess how nutrient enrichment affects growth, biomass allocation and decomposition of plant tissues of a common and widespread mangrove, Avicennia marina, and how

Waterbird communities and seed biomass in managed and reference-restored wetlands in the Mississippi Alluvial Valley

Science.gov (United States)

Tapp, Jessica L.; Weegman, Matthew M.; Webb, Elisabeth B.; Kaminski, Richard M.; Davis, J. Brian

2018-01-01

The Natural Resources Conservation Service (NRCS) commenced the Migratory Bird Habitat Initiative (MBHI) in summer 2010 after the April 2010 Deepwater Horizon oil spill in the Gulf of Mexico. The MBHI enrolled in the program 193,000 ha of private wet- and cropland inland from potential oil-impaired wetlands. We evaluated waterfowl and other waterbird use and potential seed/tuber food resources in NRCS Wetland Reserve Program easement wetlands managed via MBHI funding and associated reference wetlands in the Mississippi Alluvial Valley of Arkansas, Louisiana, Mississippi, and Missouri. In Louisiana and Mississippi, nearly three times more dabbling ducks and all ducks combined were observed on managed than reference wetlands. Shorebirds and waterbirds other than waterfowl were nearly twice as abundant on managed than referenced wetlands. In Arkansas and Missouri, managed wetlands had over twice more dabbling ducks and nearly twice as many duck species than reference wetlands. Wetlands managed via MBHI in Mississippi and Louisiana contained ≥1.3 times more seed and tuber biomass known to be consumed by waterfowl than reference wetlands. Seed and tuber resources did not differ between wetlands in Arkansas and Missouri. While other studies have documented greater waterbird densities on actively than nonmanaged wetlands, our results highlighted the potential for initiatives focused on managing conservation easements to increase waterbird use and energetic carrying capacity of restored wetlands for waterbirds.

Coastal bathymetry and backscatter data collected in 2012 from the Chandeleur Islands, Louisiana

Science.gov (United States)

DeWitt, Nancy T.; Bernier, Julie C.; Pfeiffer, William R.; Miselis, Jennifer L.; Reynolds, B.J.; Wiese, Dana S.; Kelso, Kyle W.

2014-01-01

As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off the northern Chandeleur Islands, Louisiana, in July and August of 2012. The objective of the study is to better understand barrier island geomorphic evolution, particularly storm-related depositional and erosional processes that shape the islands over annual to interannual timescales (1-5 years). Collecting geophysical data will allow us to identify relationships between the geologic history of the island and its present day morphology and sediment distribution. This mapping effort was the second in a series of three planned surveys in this area. High resolution geophysical data collected in each of 3 consecutive years along this rapidly changing barrier island system will provide a unique time-series dataset that will significantly further the analyses and geomorphological interpretations of this and other coastal systems, improving our understanding of coastal response and evolution over short time scales (1-5 years). This Data Series report includes the geophysical data that were collected during two cruises (USGS Field Activity Numbers 12BIM03 and 12BIM04) aboard the RV Survey Cat and the RV Twin Vee along the northern portion of the Chandeleur Islands, Breton National Wildlife Refuge, Louisiana. Data were acquired with the following equipment: a Systems Engineering and Assessment, Ltd., SWATHplus interferometric sonar (468 kilohertz (kHz)), an EdgeTech 424 (4-24 kHz) chirp sub-bottom profiling system, and a Knudsen 320BP (210 kHz) echosounder. This report serves as an archive of processed interferometric swath and single-beam bathymetry data. Geographic information system data products include an interpolated digital elevation model, an acoustic backscatter mosaic, trackline maps, and point data files. Additional files include error analysis maps, Field Activity

Integrating ecosystem services and climate change responses in coastal wetlands development plans for Bangladesh

NARCIS (Netherlands)

Sarwar, M.H.; Hein, L.G.; Rip, F.I.; Dearing, J.A.

2015-01-01

This study explores the integration of ecosystem services and climate change adaptation in development plans for coastal wetlands in Bangladesh. A new response framework for adaptation is proposed, based on an empirical analysis and consultations with stakeholders, using a modified version of the

Potential increase in coastal wetland vulnerability to sea-level rise suggested by considering hydrodynamic attenuation effects

Science.gov (United States)

Rodríguez, José F.; Saco, Patricia M.; Sandi, Steven; Saintilan, Neil; Riccardi, Gerardo

2017-07-01

The future of coastal wetlands and their ecological value depend on their capacity to adapt to the interacting effects of human impacts and sea-level rise. Even though extensive wetland loss due to submergence is a possible scenario, its magnitude is highly uncertain due to limited understanding of hydrodynamic and bio-geomorphic interactions over time. In particular, the effect of man-made drainage modifications on hydrodynamic attenuation and consequent wetland evolution is poorly understood. Predictions are further complicated by the presence of a number of vegetation types that change over time and also contribute to flow attenuation. Here, we show that flow attenuation affects wetland vegetation by modifying its wetting-drying regime and inundation depth, increasing its vulnerability to sea-level rise. Our simulations for an Australian subtropical wetland predict much faster wetland loss than commonly used models that do not consider flow attenuation.

Coastal vegetation invasion increases greenhouse gas emission from wetland soils but also increases soil carbon accumulation

International Nuclear Information System (INIS)

Chen, Yaping; Chen, Guangcheng; Ye, Yong

2015-01-01

Soil properties and soil–atmosphere fluxes of CO 2 , CH 4 and N 2 O from four coastal wetlands were studied throughout the year, namely, native Kandelia obovata mangrove forest vs. exotic Sonneratia apetala mangrove forest, and native Cyperus malaccensis salt marsh vs. exotic Spartina alterniflora salt marsh. Soils of the four wetlands were all net sources of greenhouse gases while Sonneratia forest contributed the most with a total soil–atmosphere CO 2 -equivalent flux of 137.27 mg CO 2 m −2 h −1 , which is 69.23%, 99.75% and 44.56% higher than that of Kandelia, Cyperus and Spartina, respectively. The high underground biomass and distinctive root structure of Sonneratia might be responsible for its high greenhouse gas emission from the soil. Soils in Spartina marsh emitted the second largest amount of total greenhouse gases but it ranked first in emitting trace greenhouse gases. Annual average CH 4 and N 2 O fluxes from Spartina soil were 13.77 and 1.14 μmol m −2 h −1 , respectively, which are 2.08 and 1.46 times that of Kandelia, 1.03 and 1.15 times of Sonneratia, and 1.74 and 1.02 times of Cyperus, respectively. Spartina has longer growing season and higher productivity than native marshes which might increase greenhouse gas emission in cold seasons. Exotic wetland soils had higher carbon stock as compared to their respective native counterparts but their carbon stocks were offset by a larger proportion because of their higher greenhouse gas emissions. Annual total soil–atmosphere fluxes of greenhouse gases reduced soil carbon burial benefits by 8.1%, 9.5%, 6.4% and 7.2% for Kandelia, Sonneratia, Cyperus and Spartina, respectively, which narrowed down the gaps in net soil carbon stock between native and exotic wetlands. The results indicated that the invasion of exotic wetland plants might convert local coastal soils into a considerable atmospheric source of greenhouse gases although they at the same time increase soil carbon accumulation

Coastal vegetation invasion increases greenhouse gas emission from wetland soils but also increases soil carbon accumulation

Energy Technology Data Exchange (ETDEWEB)

Chen, Yaping [Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen 361102, Fujian (China); Chen, Guangcheng [Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, Fujian (China); Ye, Yong, E-mail: yeyong.xmu@gmail.com [Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen 361102, Fujian (China)

2015-09-01

Soil properties and soil–atmosphere fluxes of CO{sub 2}, CH{sub 4} and N{sub 2}O from four coastal wetlands were studied throughout the year, namely, native Kandelia obovata mangrove forest vs. exotic Sonneratia apetala mangrove forest, and native Cyperus malaccensis salt marsh vs. exotic Spartina alterniflora salt marsh. Soils of the four wetlands were all net sources of greenhouse gases while Sonneratia forest contributed the most with a total soil–atmosphere CO{sub 2}-equivalent flux of 137.27 mg CO{sub 2} m{sup −2} h{sup −1}, which is 69.23%, 99.75% and 44.56% higher than that of Kandelia, Cyperus and Spartina, respectively. The high underground biomass and distinctive root structure of Sonneratia might be responsible for its high greenhouse gas emission from the soil. Soils in Spartina marsh emitted the second largest amount of total greenhouse gases but it ranked first in emitting trace greenhouse gases. Annual average CH{sub 4} and N{sub 2}O fluxes from Spartina soil were 13.77 and 1.14 μmol m{sup −2} h{sup −1}, respectively, which are 2.08 and 1.46 times that of Kandelia, 1.03 and 1.15 times of Sonneratia, and 1.74 and 1.02 times of Cyperus, respectively. Spartina has longer growing season and higher productivity than native marshes which might increase greenhouse gas emission in cold seasons. Exotic wetland soils had higher carbon stock as compared to their respective native counterparts but their carbon stocks were offset by a larger proportion because of their higher greenhouse gas emissions. Annual total soil–atmosphere fluxes of greenhouse gases reduced soil carbon burial benefits by 8.1%, 9.5%, 6.4% and 7.2% for Kandelia, Sonneratia, Cyperus and Spartina, respectively, which narrowed down the gaps in net soil carbon stock between native and exotic wetlands. The results indicated that the invasion of exotic wetland plants might convert local coastal soils into a considerable atmospheric source of greenhouse gases although they at the

Derivation of Ground Surface and Vegetation in a Coastal Florida Wetland with Airborne Laser Technology

Science.gov (United States)

Raabe, Ellen A.; Harris, Melanie S.; Shrestha, Ramesh L.; Carter, William E.

2008-01-01

The geomorphology and vegetation of marsh-dominated coastal lowlands were mapped from airborne laser data points collected on the Gulf Coast of Florida near Cedar Key. Surface models were developed using low- and high-point filters to separate ground-surface and vegetation-canopy intercepts. In a non-automated process, the landscape was partitioned into functional landscape units to manage the modeling of key landscape features in discrete processing steps. The final digital ground surface-elevation model offers a faithful representation of topographic relief beneath canopies of tidal marsh and coastal forest. Bare-earth models approximate field-surveyed heights by + 0.17 m in the open marsh and + 0.22 m under thick marsh or forest canopy. The laser-derived digital surface models effectively delineate surface features of relatively inaccessible coastal habitats with a geographic coverage and vertical detail previously unavailable. Coastal topographic details include tidal-creek tributaries, levees, modest topographic undulations in the intertidal zone, karst features, silviculture, and relict sand dunes under coastal-forest canopy. A combination of laser-derived ground-surface and canopy-height models and intensity values provided additional mapping capabilities to differentiate between tidal-marsh zones and forest types such as mesic flatwood, hydric hammock, and oak scrub. Additional derived products include fine-scale shoreline and topographic profiles. The derived products demonstrate the capability to identify areas of concern to resource managers and unique components of the coastal system from laser altimetry. Because the very nature of a wetland system presents difficulties for access and data collection, airborne coverage from remote sensors has become an accepted alternative for monitoring wetland regions. Data acquisition with airborne laser represents a viable option for mapping coastal topography and for evaluating habitats and coastal change on marsh

Linking the historic 2011 Mississippi River flood to coastal wetland sedimentation

Science.gov (United States)

Falcini, Federico; Khan, Nicole S.; Macelloni, Leonardo; Horton, Benjamin P.; Lutken, Carol B.; McKee, Karen L.; Santoleri, Rosalia; Colella, Simone; Li, Chunyan; Volpe, Gianluca; D’Emidio, Marco; Salusti, Alessandro; Jerolmack, Douglas J.

2012-01-01

Wetlands in the Mississippi River deltaic plain are deteriorating in part because levees and control structures starve them of sediment. In Spring of 2011 a record-breaking flood brought discharge on the lower Mississippi River to dangerous levels, forcing managers to divert up to 3500 m3/s-1 of water to the Atchafalaya River Basin. Here we quantify differences between the Mississippi and Atchafalaya River inundation and sediment-plume patterns using field-calibrated satellite data, and assess the impact these outflows had on wetland sedimentation. We characterize hydrodynamics and suspended sediment patterns of the Mississippi River plume using in-situ data collected during the historic flood. We show that the focused, high-momentum jet from the leveed Mississippi delivered sediment far offshore. In contrast, the plume from the Atchafalaya was more diffuse; diverted water inundated a large area; and sediment was trapped within the coastal current. Maximum sedimentation (up to several centimetres) occurred in the Atchafalaya Basin despite the larger sediment load carried by the Mississippi. Minimum accumulation occurred along the shoreline between these river sources. Our findings provide a mechanistic link between river-mouth dynamics and wetland sedimentation patterns that is relevant for plans to restore deltaic wetlands using artificial diversions.

Terrestrial laser scanning to quantify above-ground biomass of structurally complex coastal wetland vegetation

Science.gov (United States)

Owers, Christopher J.; Rogers, Kerrylee; Woodroffe, Colin D.

2018-05-01

Above-ground biomass represents a small yet significant contributor to carbon storage in coastal wetlands. Despite this, above-ground biomass is often poorly quantified, particularly in areas where vegetation structure is complex. Traditional methods for providing accurate estimates involve harvesting vegetation to develop mangrove allometric equations and quantify saltmarsh biomass in quadrats. However broad scale application of these methods may not capture structural variability in vegetation resulting in a loss of detail and estimates with considerable uncertainty. Terrestrial laser scanning (TLS) collects high resolution three-dimensional point clouds capable of providing detailed structural morphology of vegetation. This study demonstrates that TLS is a suitable non-destructive method for estimating biomass of structurally complex coastal wetland vegetation. We compare volumetric models, 3-D surface reconstruction and rasterised volume, and point cloud elevation histogram modelling techniques to estimate biomass. Our results show that current volumetric modelling approaches for estimating TLS-derived biomass are comparable to traditional mangrove allometrics and saltmarsh harvesting. However, volumetric modelling approaches oversimplify vegetation structure by under-utilising the large amount of structural information provided by the point cloud. The point cloud elevation histogram model presented in this study, as an alternative to volumetric modelling, utilises all of the information within the point cloud, as opposed to sub-sampling based on specific criteria. This method is simple but highly effective for both mangrove (r2 = 0.95) and saltmarsh (r2 > 0.92) vegetation. Our results provide evidence that application of TLS in coastal wetlands is an effective non-destructive method to accurately quantify biomass for structurally complex vegetation.

Hurricane Matthew's Effects on Wetland Sources of Organic Matter to North Carolina Coastal Waters.

Science.gov (United States)

Rudolph, J. C.; Osburn, C. L.; Paerl, H. W.; Hounshell, A.

2017-12-01

Increased frequency and intensity of storm events such as tropical cyclones will have a major impact on estuarine and coastal biogeochemical cycling. Here, we determined the sources of dissolved and particulate organic matter (DOM and POM) as part of a larger study to quantify the short-term (several months) response of carbon and nitrogen cycling in the Neuse River Estuary-Pamlico Sound (NRE-PS) ecosystem to floodwaters associated with Hurricane Matthew. Sampling was conducted weekly in both the NRE-PS (October 2016 to January 2017), the Neuse River (NR) (October to December 2016) and in freshwater wetlands of the Neuse River above head of tide in March 2017. Specific ultraviolet (UV) absorbance at 254 nm (SUVA254) and stable carbon isotope ratios (δ13C-DOC) were used to determine the sources of DOM and POM transported to the NRE-PS in post-hurricane floodwaters. For DOM, SUVA254 values increased from 3.23 ±0.52 mg C L-1 m-1 in the NR to 4.14±0.52 mg C L-1 m-1 in the NRE and then declined to 3.63±0.32 mg C L-1 m-1 in PS. Combined with depleted δ13C-DOC values (-26 to -32‰) and elevated C:N values in the estuary and sound, these results confirm continued loading of fresh terrestrial organic matter into NRE-PS weeks after the storm. For POM, δ13C-POC and C:N ratio results likewise indicated a terrestrial source in floodwaters. SUVA254 values >3.5 mg C L-1 m-1 coupled with the depleted δ13C values and large C:N values were consistent with DOM primarily sourced from wetlands (e.g., wetland SUVA254 = 3.77±0.52 mg C L-1 m-1 in March 2017). We hypothesize that floodwaters connected riverine wetlands to the main channel of the NR, exporting DOM and POM into the NRE-PS. Our results indicate that upstream wetlands play a central and potentially significant role in organic matter enrichment and metabolism of estuarine and coastal waters, in light of increasing frequencies and intensities of tropical cyclones impacting coastal watersheds.

ENVIRONMENTAL EFFECTS OF A GOLF COMPLEX ON COASTAL WETLANDS IN THE GULF OF MEXICO

Science.gov (United States)

The increasing density of golf courses represents a potential source of contamination to nearby coastal wetlands and other near-shore areas. The chemical and biological magnitude of the problem is almost unknown. To provide perspective on this issue, the effects of golf complex r...

Wetlands and Sustainability

Directory of Open Access Journals (Sweden)

Richard Smardon

2014-11-01

Full Text Available This editorial provides an overview of the special issue “Wetlands and Sustainability”. In particular, the special issue contains a review of Paul Keddy’s book “Wetland Ecology” with specific reference to wetland sustainability. It also includes papers addressing wetland data acquisition via radar and remote sensing to better understand wetland system dynamics, hydrologic processes linked to wetland stress and restoration, coastal wetlands land use conflict/management, and wetland utilization for water quality treatment.

Palynological reconstruction of environmental changes in coastal wetlands of the Florida Everglades since the mid-Holocene

Science.gov (United States)

Yao, Qiang; Liu, Kam-biu; Platt, William J.; Rivera-Monroy, Victor H.

2015-05-01

Palynological, loss-on-ignition, and X-ray fluorescence data from a 5.25 m sediment core from a mangrove forest at the mouth of the Shark River Estuary in the southwestern Everglades National Park, Florida were used to reconstruct changes occurring in coastal wetlands since the mid-Holocene. This multi-proxy record contains the longest paleoecological history to date in the southwestern Everglades. The Shark River Estuary basin was formed 5700 cal yr BP in response to increasing precipitation. Initial wetlands were frequently-burned short-hydroperiod prairies, which transitioned into long-hydroperiod prairies with sloughs in which peat deposits began to accumulate continuously about 5250 cal yr BP. Our data suggest that mangrove communities started to appear after 3800 cal yr BP; declines in the abundance of charcoal suggested gradual replacement of fire-dominated wetlands by mangrove forest over the following 2650 yr. By 1150 cal yr BP, a dense Rhizophora mangle dominated mangrove forest had formed at the mouth of the Shark River. The mangrove-dominated coastal ecosystem here was established at least 2000 yr later than has been previously estimated.

Transplanting native dominant plants to facilitate community development in restored coastal plain wetlands.

Energy Technology Data Exchange (ETDEWEB)

De Steven, Diane; Sharitz, Rebecca R.

2007-12-01

Abstract: Drained depressional wetlands are typically restored by plugging ditches or breaking drainage tiles to allow recovery of natural ponding regimes, while relying on passive recolonization from seed banks and dispersal to establish emergent vegetation. However, in restored depressions of the southeastern United States Coastal Plain, certain characteristic rhizomatous graminoid species may not recolonize because they are dispersal-limited and uncommon or absent in the seed banks of disturbed sites. We tested whether selectively planting such wetland dominants could facilitate restoration by accelerating vegetative cover development and suppressing non-wetland species. In an operational-scale project in a South Carolina forested landscape, drained depressional wetlands were restored in early 2001 by completely removing woody vegetation and plugging surface ditches. After forest removal, tillers of two rhizomatous wetland grasses (Panicum hemitomon, Leersia hexandra) were transplanted into singlespecies blocks in 12 restored depressions that otherwise were revegetating passively. Presence and cover of all plant species appearing in planted plots and unplanted control plots were recorded annually. We analyzed vegetation composition after two and four years, during a severe drought (2002) and after hydrologic recovery (2004). Most grass plantings established successfully, attaining 15%–85% cover in two years. Planted plots had fewer total species and fewer wetland species compared to control plots, but differences were small. Planted plots achieved greater total vegetative cover during the drought and greater combined cover of wetland species in both years. By 2004, planted grasses appeared to reduce cover of non-wetland species in some cases, but wetter hydrologic conditions contributed more strongly to suppression of non-wetland species. Because these two grasses typically form a dominant cover matrix in herbaceous depressions, our results indicated that

Accelerated relative sea-level rise and rapid coastal erosion: Testing a causal relationship for the Louisiana barrier islands

Science.gov (United States)

List, J.H.; Sallenger, A.H.; Hansen, M.E.; Jaffe, B.E.

1997-01-01

The role of relative sea-level rise as a cause for the rapid erosion of Louisiana's barrier island coast is investigated through a numerical implementation of a modified Bruun rule that accounts for the low percentage of sand-sized sediment in the eroding Louisiana shoreface. Shore-normal profiles from 150 km of coastline west of the Mississippi delta are derived from bathymetric surveys conducted during the 1880s. 1930s and 1980s. An RMS difference criterion is employed to test whether an equilibrium profile form is maintained between survey years. Only about half the studied profiles meet the equilibrium Criterion this represents a significant limitation on the potential applicability of the Bruun rule. The profiles meeting the equilibrium criterion, along with measured rates of relative sea-level rise, are used to hindcast shoreline retreat rates at 37 locations within the study area. Modeled and observed shoreline retreat rates show no significant correlation. Thus in terms of the Bruun approach relative sea-level rise has no power for hindcasting (and presumably forecasting) rates of coastal erosion for the Louisiana barrier islands.

Nekton communities in Hawaiian coastal wetlands: The distribution and abundance of introduced fish species

Science.gov (United States)

Richard Ames MacKenzie; Gregory L. Bruland

2012-01-01

Nekton communities were sampled from 38 Hawaiian coastal wetlands from 2007 to 2009 using lift nets, seines, and throw nets in an attempt to increase our understanding of the nekton assemblages that utilize these poorly studied ecosystems. Nekton were dominated by exotic species, primarily poeciliids (Gambusia affinis, Poecilia...

Louisiana ESI: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for waterfowl species and shorebirds in coastal Louisiana. Vector polygons in this data set represent...

Louisiana ESI: FISH (Fish Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for freshwater (inland) fish species in coastal Louisiana. Vector polygons represent water-bodies and other...

A conceptual hydrologic model for a forested Carolina bay depressional wetland on the Coastal Plain of South Carolina, USA

Science.gov (United States)

Jennifer E. Pyzoha; Timothy J. Callahan; Ge Sun; Carl C. Trettin; Masato Miwa

2008-01-01

This paper describes how climate influences the hydrology of an ephemeral depressional wetland. Surface water and groundwater elevation data were collected for 7 years in a Coastal Plain watershed in South Carolina USA containing depressional wetlands, known as Carolina bays. Rainfall and temperature data were compared with water-table well and piezometer data in and...

A Mechanistically Informed User-Friendly Model to Predict Greenhouse Gas (GHG) Fluxes and Carbon Storage from Coastal Wetlands

Science.gov (United States)

Abdul-Aziz, O. I.; Ishtiaq, K. S.

2015-12-01

We present a user-friendly modeling tool on MS Excel to predict the greenhouse gas (GHG) fluxes and estimate potential carbon sequestration from the coastal wetlands. The dominant controls of wetland GHG fluxes and their relative mechanistic linkages with various hydro-climatic, sea level, biogeochemical and ecological drivers were first determined by employing a systematic data-analytics method, including Pearson correlation matrix, principal component and factor analyses, and exploratory partial least squares regressions. The mechanistic knowledge and understanding was then utilized to develop parsimonious non-linear (power-law) models to predict wetland carbon dioxide (CO2) and methane (CH4) fluxes based on a sub-set of climatic, hydrologic and environmental drivers such as the photosynthetically active radiation, soil temperature, water depth, and soil salinity. The models were tested with field data for multiple sites and seasons (2012-13) collected from the Waquoit Bay, MA. The model estimated the annual wetland carbon storage by up-scaling the instantaneous predicted fluxes to an extended growing season (e.g., May-October) and by accounting for the net annual lateral carbon fluxes between the wetlands and estuary. The Excel Spreadsheet model is a simple ecological engineering tool for coastal carbon management and their incorporation into a potential carbon market under a changing climate, sea level and environment. Specifically, the model can help to determine appropriate GHG offset protocols and monitoring plans for projects that focus on tidal wetland restoration and maintenance.

Environmental evolution records reflected by radionuclides in the sediment of coastal wetlands: A case study in the Yellow River Estuary wetland.

Science.gov (United States)

Wang, Qidong; Song, Jinming; Li, Xuegang; Yuan, Huamao; Li, Ning; Cao, Lei

2016-10-01

Vertical profiles of environmental radionuclides ( 210 Pb, 137 Cs, 238 U, 232 Th, 226 Ra and 4 0 K) in a sediment core (Y1) of the Yellow River Estuary wetland were investigated to assess whether environmental evolutions in the coastal wetland could be recorded by the distributions of radionuclides. Based on 210 Pb and 137 Cs dating, the average sedimentation rate of core Y1 was estimated to be 1.0 cm y -1 . Vertical distributions of natural radionuclides ( 238 U, 232 Th, 226 Ra and 40 K) changed dramatically, reflecting great changes in sediment input. Concentrations of 238 U, 232 Th, 226 Ra and 40 K all had significant positive relationships with organic matter and clay content, but their distributions were determined by different factors. Factor analysis showed that 238 U was determined by the river sediment input while 226 Ra was mainly affected by the seawater erosion. Environmental changes such as river channel migrations and sediment discharge variations could always cause changes in the concentrations of radionuclides. High concentrations of 238 U and 226 Ra were consistent with high accretion rate. Frequent seawater intrusion decreased the concentration of 226 Ra significantly. The value of 238 U/ 226 Ra tended to be higher when the sedimentation rate was low and tide intrusion was frequent. In summary, environmental evolutions in the estuary coastal wetland could be recorded by the vertical profiles of natural radionuclides. Copyright © 2016 Elsevier Ltd. All rights reserved.

Louisiana ESI: NESTS (Nest Points)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for seabird and wading bird nesting colonies in coastal Louisiana. Vector points in this data set represent...

Factors influencing CO2 and CH4 emissions from coastal wetlands in the Liaohe Delta, Northeast China

DEFF Research Database (Denmark)

Olsson, L.; Ye, S.; Wei, M.

2015-01-01

temperature and vegetation on CH4 emissions and ecosystem respiration (Reco) from five coastal wetlands in the Liaohe Delta, northeast China: two Phragmites australis (common reed) wetlands, two Suaeda salsa (sea blite) marshes and a rice (Oryza sativa) paddy. Throughout the growing season, the Suaeda...

Digging Deep: how the convergence of national-scale and field-based soil core data shines a light on sustainability of wetland carbon sequestration

Science.gov (United States)

Windham-Myers, L.; Holmquist, J. R.; Sundquist, E. T.; Drexler, J. Z.; Bliss, N.

2016-12-01

Wetland soils have long been recognized as conditional archives of past environments, including vegetation structure, nutrient status, sediment supply and the variability in those factors. Both sedimentary processes and organic accretion processes form the soil matrix that identifies wetland soils as "hydric" while also providing archival insights. As repositories of information on net biogeochemical processes, their down-core and across-site structure can show both consistency and distinction. Through several related studies, we have been exploring the use of component-level U.S. Natural Resources Conservation Service (NRCS) Soil Survey data (SSURGO) to map carbon density to 1m depth across wetlands of the US, with an emphasis on coastal wetlands. To assess the accuracy of mapped carbon data from SSURGO, several field-generated datasets (public or compiled for the NASA-funded Blue Carbon Monitoring Project) have been extracted for key metrics such as dry bulk density (g/cc), organic carbon content (%C by combustion) and the combination, soil carbon density (g C /cc) with depth. These profiles indicate ecogeomorphic feedbacks of elevation, vegetation structure and biogeochemical processes through millennia, illustrating both resilience and shifts in behavior that constrain wetland extent as well as wetland function. National datasets such as SSURGO and validation datasets such as the EPA's National Wetland Condition Assessment (NWCA) and Louisiana's Coastwide Reference Monitoring System (CRMS) are publically available and have been underutilized for predicting and/or validating changes in wetland carbon dynamics. We have explored their use for interpretating and understanding changing carbon accretion rates, changing wetland extents through elevation gain or loss, and changing methane emissions. This talk will focus on insights for wetland carbon sequestration functions as determined by soil core structure, both for coastal settings and potentially for inland

Hydrological behavior of coastal lagoons associated to wetlands, an example from southernmost bahía Samborombón (Argentina).

Science.gov (United States)

Tejada Tejada, Macarena; Carol, Eleanora; Galliari, Julieta; Richiano, Sebastian

2017-04-01

Coastal wetlands are located at a critical interface between the terrestrial and marine environments and are ideally positioned to reduce impacts from land-based sources. At the southern region of Bahía Samborombón (Argentina) the wetlands includes several small coastal lagoons developed inside of a sandy spike. The main object of this work is to analyze the hydrological behavior of the lagoons evaluating their role in the maintenances of the wetland. In order to do this, satellite image analysis was performed to identify the marshy areas, drainage features, morphology and connections of the lagoons, both with the tidal flows from the Río de la Plata estuary and from the Argentine Sea. Field surveys were carried out in one of the lagoons to define their geological and geomorphological characteristics. After that, a monitoring network was designed for sampling the superficial and the underground water, additionally electrical conductivity and pH of the water were determined in situ. In all the water samples extracted the content of majority ions was determined by standard methods. Complementary, sedimentological and malacological aspects were observed at several stations in the lagoon. The obtained results allow us to recognize that the tidal flow that enters from the sea, at least in the studied lagoon, is the main hydrological sustenance of the wetland. This flow enters mainly using one tidal channel which connects (in a semi-permanent way) the sea with the lagoon during extraordinary tide and storm events. During low tide the lagoon loses connection and the drainage towards the sea is scarce. The tidal water that accumulates in the lagoon is subsequently evaporated causing an increase in the salinity of the surface water to values higher than the sea. Groundwater that accumulates through the infiltration of rainfall in the sandy sediments of the spike also discharges to the lagoon and supports the wetland surrounding the coastal lagoon. This flow, even when it

Wetland education through cooperative programs between coastal Carolina University and Horry County public schools

Science.gov (United States)

Sharon L. Gilman

2000-01-01

Horry County, in the Coastal Plain of South Carolina, isapproximately 50 percent wetlands. The Waccamaw Region (Horry, Georgetown, and Williamsburg Counties) has experienced a 58-percent population increase during theperiod from 1960 to 1990. Population growth trends suggest that from 1990 to 2020, the total daily population will increase by 125 percent, representing...

ALL THAT "PHRAG": BRINGING ENGINEERING, WETLAND ECOLOGY, ENVIRONMENTAL SCIENCE, AND LANDSCAPE ECOLOGY TO BEAR ON THE QUESTION OF COMMON REED IN GREAT LAKES COASTAL WETLANDS

Science.gov (United States)

Coastal wetlands are among the most fragmented and disturbed ecosystems and the Great Lakes are no exception. One possible result is the observed increase in the presence and dominance of invasive and other opportunistic plant species, such as the common reed (Phragmites australi...

High spatial variability in biogeochemical rates and microbial communities across Louisiana salt marsh landscapes

Science.gov (United States)

Roberts, B. J.; Chelsky, A.; Bernhard, A. E.; Giblin, A. E.

2017-12-01

Salt marshes are important sites for retention and transformation of carbon and nutrients. Much of our current marsh biogeochemistry knowledge is based on sampling at times and in locations that are convenient, most often vegetated marsh platforms during low tide. Wetland loss rates are high in many coastal regions including Louisiana which has the highest loss rates in the US. This loss not only reduces total marsh area but also changes the relative allocation of subhabitats in the remaining marsh. Climate and other anthropogenic changes lead to further changes including inundation patterns, redox conditions, salinity regimes, and shifts in vegetation patterns across marsh landscapes. We present results from a series of studies examining biogeochemical rates, microbial communities, and soil properties along multiple edge to interior transects within Spartina alterniflora across the Louisiana coast; between expanding patches of Avicennia germinans and adjacent S. alterniflora marshes; in soils associated with the four most common Louisiana salt marsh plants species; and across six different marsh subhabitats. Spartina alterniflora marsh biogeochemistry and microbial populations display high spatial variability related to variability in soil properties which appear to be, at least in part, regulated by differences in elevation, hydrology, and redox conditions. Differences in rates between soils associated with different vegetation types were also related to soil properties with S. alterniflora soils often yielding the lowest rates. Biogeochemical process rates vary significantly across marsh subhabitats with individual process rates differing in their hotspot habitat(s) across the marsh. Distinct spatial patterns may influence the roles that marshes play in retaining and transforming nutrients in coastal regions and highlight the importance of incorporating spatial sampling when scaling up plot level measurements to landscape or regional scales.

An Initial Assessment of the Economic Value of Coastal and Freshwater Wetlands in West Asia

Directory of Open Access Journals (Sweden)

Florian V. Eppink

2014-06-01

Full Text Available Many countries in West Asia, defined in this study as the Arabic-speaking countries of the Arabian Peninsula plus Turkey and Iran, have enacted environmental conservation laws but regional underlying drivers of environment change, such as rising incomes and fast-growing populations, continue to put pressure on remaining wetlands. This paper aims to inform conservation efforts by presenting the first regional assessment of the economic value of coastal and freshwater wetlands in West Asia. Using scenario analysis we find that, dependent on the discount rate used, the present value of the regional economic loss of not protecting wetlands by 2050 is between US dollar 2.3 billion and US dollar 7.2 billion (expressed in 2007 US dollars. The method used for this assessment, however, is not suitable for expressing national realities adequately. We therefore suggest that detailed localized studies are conducted to improve insight into the drivers and the social and economic effects of wetland loss in West Asia.

Applicability Assessment of Uavsar Data in Wetland Monitoring: a Case Study of Louisiana Wetland

Science.gov (United States)

Zhao, J.; Niu, Y.; Lu, Z.; Yang, J.; Li, P.; Liu, W.

2018-04-01

Wetlands are highly productive and support a wide variety of ecosystem goods and services. Monitoring wetland is essential and potential. Because of the repeat-pass nature of satellite orbit and airborne, time-series of remote sensing data can be obtained to monitor wetland. UAVSAR is a NASA L-band synthetic aperture radar (SAR) sensor compact pod-mounted polarimetric instrument for interferometric repeat-track observations. Moreover, UAVSAR images can accurately map crustal deformations associated with natural hazards, such as volcanoes and earthquakes. And its polarization agility facilitates terrain and land-use classification and change detection. In this paper, the multi-temporal UAVSAR data are applied for monitoring the wetland change. Using the multi-temporal polarimetric SAR (PolSAR) data, the change detection maps are obtained by unsupervised and supervised method. And the coherence is extracted from the interfometric SAR (InSAR) data to verify the accuracy of change detection map. The experimental results show that the multi-temporal UAVSAR data is fit for wetland monitor.

Scientific, Social, and Institutional Constraints Facing Coastal Restoration in Louisiana

Science.gov (United States)

Kleiss, B.; Shabman, L. A.; Brown, G.

2017-12-01

Due to multiple stressors, including subsidence, accelerated sea level rise, canal construction, tropical storm damages, and basin-wide river management decisions, southern Louisiana is experiencing some of the world's highest rates of coastal land loss. Although ideas abound, the solutions proposed to mitigate for land loss are often uncertain, complex, expensive, and difficult. There are significant scientific uncertainties associated with fundamental processes including the spatial distribution of rates of subsidence, the anticipated impacts of increased inundation on marsh plant species and questions about the resilience of engineered solutions. Socially and politically, there is the need to balance navigation, flood risk management and environmental restoration with the fact that the land involved is largely privately owned and includes many communities and towns. And layered within this, there are federal and state regulatory constraints which seek to follow a myriad of existing State and Federal laws, protect the benefits realized from previous federal investments, and balance the conflicting interests of a large number of stakeholders. Additionally, current practice when implementing some environmental regulations is to assess impacts against the baseline of current conditions, not projected future, non-project conditions, making it difficult to receive a permit for projects which may have a short-term detriment, but hope for a long-term benefit. The resolution (or lack thereof) of these issues will serve to inform similar future struggles in other low lying coastal areas around the globe.

Developing Remote Sensing Products for Monitoring and Modeling Great Lakes Coastal Wetland Vulnerability to Climate Change and Land Use

Science.gov (United States)

Bourgeau-Chavez, L. L.; Miller, M. E.; Battaglia, M.; Banda, E.; Endres, S.; Currie, W. S.; Elgersma, K. J.; French, N. H. F.; Goldberg, D. E.; Hyndman, D. W.

2014-12-01

Spread of invasive plant species in the coastal wetlands of the Great Lakes is degrading wetland habitat, decreasing biodiversity, and decreasing ecosystem services. An understanding of the mechanisms of invasion is crucial to gaining control of this growing threat. To better understand the effects of land use and climatic drivers on the vulnerability of coastal zones to invasion, as well as to develop an understanding of the mechanisms of invasion, research is being conducted that integrates field studies, process-based ecosystem and hydrological models, and remote sensing. Spatial data from remote sensing is needed to parameterize the hydrological model and to test the outputs of the linked models. We will present several new remote sensing products that are providing important physiological, biochemical, and landscape information to parameterize and verify models. This includes a novel hybrid radar-optical technique to delineate stands of invasives, as well as natural wetland cover types; using radar to map seasonally inundated areas not hydrologically connected; and developing new algorithms to estimate leaf area index (LAI) using Landsat. A coastal map delineating wetland types including monocultures of the invaders (Typha spp. and Phragmites austrailis) was created using satellite radar (ALOS PALSAR, 20 m resolution) and optical data (Landsat 5, 30 m resolution) fusion from multiple dates in a Random Forests classifier. These maps provide verification of the integrated model showing areas at high risk of invasion. For parameterizing the hydrological model, maps of seasonal wetness are being developed using spring (wet) imagery and differencing that with summer (dry) imagery to detect the seasonally wet areas. Finally, development of LAI remote sensing high resolution algorithms for uplands and wetlands is underway. LAI algorithms for wetlands have not been previously developed due to the difficulty of a water background. These products are being used to

Utilizing NASA EOS to Assist in Determining Suitable Planting Locations for Bottomland Hardwood Trees in St. Bernard Parish, Louisiana

Science.gov (United States)

Reahard, R. R.; Arguelles, M.; Ewing, M.; Kelly, C.; Strong, E.

2012-12-01

St. Bernard Parish, located in southeast Louisiana, is rapidly losing coastal forests and wetlands due to a variety of natural and anthropogenic disturbances (e.g. subsidence, saltwater intrusion, low sedimentation, nutrient deficiency, herbivory, canal dredging, levee construction, spread of invasive species, etc.). After Hurricane Katrina severely impacted the area in 2005, multiple Non-Governmental Organizations (NGOs) have focused not only on rebuilding destroyed dwellings, but on rebuilding the ecosystems that once protected the citizens of St. Bernard Parish. Volunteer groups, NGOs, and government entities often work separately and independently of each other and use different sets of information to choose the best planting sites for restoring coastal forests. Using NASA Earth Observing Systems (EOS), Natural Resource Conservation Service (NRCS) soil surveys, and ancillary road and canal data in conjunction with ground truthing, the team created maps of optimal planting sites for several species of bottomland hardwood trees to aid in unifying these organizations, who share a common goal, under one plan. The methodology for this project created a comprehensive Geographic Information System (GIS) to help identify suitable planting sites in St. Bernard Parish. This included supplementing existing elevation data using Digital Elevation Models derived from LIDAR data, and determining existing land cover in the study area from classified Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data from a single low-altitude swath was used to assess the health of vegetation over an area near the Mississippi River Gulf Outlet Canal (MRGO) and Bayou La Loutre. Historic extent of coastal forests was also mapped using aerial photos collected between 1952 and 1956. The final products demonstrated yet another application of NASA EOS in the rebuilding and monitoring of coastal ecosystems in

Louisiana ESI: MGT (Management Area Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains boundaries for managed lands in coastal Louisiana. Vector polygons in this data set represent the management areas. Location-specific type and...

How to preserve coastal wetlands, threatened by climate change-driven rises in sea level.

Science.gov (United States)

Ivajnšič, Danijel; Kaligarič, Mitja

2014-10-01

A habitat transition model, based on the correlation between individual habitats and micro-elevation intervals, showed substantial changes in the future spatial distributions of coastal habitats. The research was performed within two protected areas in Slovenia: Sečovlje Salina Nature Park and Škocjan Inlet Nature Reserve. Shifts between habitats will occur, but a general decline of 42 % for all Natura 2000 habitats is projected by 2060, according to local or global (IPCC AR4) sea level rise predictions. Three different countermeasures for the long-term conservation of targeted habitat types were proposed. The most "natural" is displacement of coastal habitats using buffer zones (1) were available. Another solution is construction of artificial islets, made of locally dredged material (2); a feasible solution in both protected areas. Twenty-two islets and a dried salt pan zone at the desired elevations suitable for those habitats that have been projected to decease in area would offer an additional 10 ha in the Sečovlje Salina. Twenty-one islets and two peninsulas at two different micro-altitudes would ensure the survival of 13 ha of three different habitats. In the area of Sečovlje Salina, abandoned salt pans could be terrestrialized by using permanent, artificial sea barriers, in a manner close to poldering (3). By using this countermeasure, another 32 ha of targeted habitat could be preserved. It can be concluded that, for each coastal area, where wetland habitats will shrink, strategic plans involving any of the three solutions should be prepared well in advance. The specific examples provided might facilitate adaptive management of coastal wetlands in general.

An Improved Ocean Observing System for Coastal Louisiana: WAVCIS (WAVE-CURRENT-SURGE Information System )

Science.gov (United States)

Zhang, X.; Stone, G. W.; Gibson, W. J.; Braud, D.

2005-05-01

WAVCIS is a regional ocean observing and forecasting system. It was designed to measure, process, forecast, and distribute oceanographic and meteorological information. WAVCIS was developed and is maintained by the Coastal Studies Institute at Louisiana State University. The in-situ observing stations are distributed along the central Louisiana and Mississippi coast. The forecast region covers the entire Gulf of Mexico with emphasis on offshore Louisiana. By using state-of-the-art instrumentation, WAVCIS measures directional waves, currents, temperature, water level, conductivity, turbidity, salinity, dissolved oxygen, chlorophyll, Meteorological parameters include wind speed and direction, air pressure and temperature visibility and humidity. Through satellite communication links, the measured data are transmitted to the WAVCIS laboratory. After processing, they are available to the public via the internet on a near real-time basis. WAVCIS also includes a forecasting capability. Waves, tides, currents, and winds are forecast daily for up to 80 hours in advance. There are a number of numerical wave and surge models that can be used for forecasts. WAM and SWAN are used for operational purposes to forecast sea state. Tides at each station are predicted based on the harmonic constants calculated from past in-situ observations at respective sites. Interpolated winds from the ETA model are used as input forcing for waves. Both in-situ and forecast information are available online to the users through WWW. Interactive GIS web mapping is implemented on the WAVCIS webpage to visualize the model output and in-situ observational data. WAVCIS data can be queried, retrieved, downloaded, and analyzed through the web page. Near real-time numerical model skill assessment can also be performed by using the data from in-situ observing stations.

Soil color indicates carbon and wetlands: developing a color-proxy for soil organic carbon and wetland boundaries on sandy coastal plains in South Africa.

Science.gov (United States)

Pretorius, M L; Van Huyssteen, C W; Brown, L R

2017-10-13

A relationship between soil organic carbon and soil color is acknowledged-albeit not a direct one. Since heightened carbon contents can be an indicator of wetlands, a quantifiable relationship between color and carbon might assist in determining wetland boundaries by rapid, field-based appraisal. The overarching aim of this initial study was to determine the potential of top soil color to indicate soil organic carbon, and by extension wetland boundaries, on a sandy coastal plain in South Africa. Data were collected from four wetland types in northern KwaZulu-Natal in South Africa. Soil samples were taken to a depth of 300 mm in three transects in each wetland type and analyzed for soil organic carbon. The matrix color was described using a Munsell soil color chart. Various color indices were correlated with soil organic carbon. The relationship between color and carbon were further elucidated using segmented quantile regression. This showed that potentially maximal carbon contents will occur at values of low color indices, and predictably minimal carbon contents will occur at values of low or high color indices. Threshold values can thus be used to make deductions such as "when the sum of dry and wet Value and Chroma values is 9 or more, carbon content will be 4.79% and less." These threshold values can then be used to differentiate between wetland and non-wetland sites with a 70 to 100% certainty. This study successfully developed a quantifiable correlation between color and carbon and showed that wetland boundaries can be determined based thereon.

The origin and disappearance of the late Pleistocene-early Holocene short-lived coastal wetlands along the Carmel coast, Israel

Science.gov (United States)

Sivan, Dorit; Greenbaum, Noam; Cohen-Seffer, Ronit; Sisma-Ventura, Guy; Almogi-Labin, Ahuva

The formation of short-lived backswamps along the Carmel coast of Israel coincides with the rapid global sea-level rise during the late Pleistocene-early Holocene transition. The current study shows that the wetland phenomena originated around 10,000 yr ago and dried up shortly before the local Pre-Pottery Neolithic humans settled on the wetland dark clay sediments 9430 cal yr BP. Palaeontological and stable-isotope data were used in this study to elucidate previously published sedimentological reconstruction obtained from a core drilled into the western trough of the Carmel coastal plain. The water body contained typical brackish calcareous fauna, with variable numerical abundance and low species richness of ostracods and foraminifera. The δ 18O and δ 13C of the ostracod Cyprideis torosa show close similarity to the present Pleistocene coastal aquifer isotopic values. This study therefore concludes that the wetlands were shallow-water bodies fed by groundwater, with no evidence of sea-water mixing. It seems that they developed as the result of high groundwater levels, transportation of sediments landward, and deposition of sand bars at the paleo-river mouths. It is still not fully understood why these wetlands deteriorated abruptly and disappeared within less than 1000 yr.

Marsh collapse thresholds for coastal Louisiana estimated using elevation and vegetation index data

Science.gov (United States)

Couvillion, Brady R.; Beck, Holly

2013-01-01

Forecasting marsh collapse in coastal Louisiana as a result of changes in sea-level rise, subsidence, and accretion deficits necessitates an understanding of thresholds beyond which inundation stress impedes marsh survival. The variability in thresholds at which different marsh types cease to occur (i.e., marsh collapse) is not well understood. We utilized remotely sensed imagery, field data, and elevation data to help gain insight into the relationships between vegetation health and inundation. A Normalized Difference Vegetation Index (NDVI) dataset was calculated using remotely sensed data at peak biomass (August) and used as a proxy for vegetation health and productivity. Statistics were calculated for NDVI values by marsh type for intermediate, brackish, and saline marsh in coastal Louisiana. Marsh-type specific NDVI values of 1.5 and 2 standard deviations below the mean were used as upper and lower limits to identify conditions indicative of collapse. As marshes seldom occur beyond these values, they are believed to represent a range within which marsh collapse is likely to occur. Inundation depth was selected as the primary candidate for evaluation of marsh collapse thresholds. Elevation relative to mean water level (MWL) was calculated by subtracting MWL from an elevation dataset compiled from multiple data types including light detection and ranging (lidar) and bathymetry. A polynomial cubic regression was used to examine a random subset of pixels to determine the relationship between elevation (relative to MWL) and NDVI. The marsh collapse uncertainty range values were found by locating the intercept of the regression line with the 1.5 and 2 standard deviations below the mean NDVI value for each marsh type. Results indicate marsh collapse uncertainty ranges of 30.7–35.8 cm below MWL for intermediate marsh, 20–25.6 cm below MWL for brackish marsh, and 16.9–23.5 cm below MWL for saline marsh. These values are thought to represent the ranges of

Louisiana ESI: REPTILES (Reptile and Amphibian Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for reptiles and amphibians in coastal Louisiana. Vector polygons represent reptile and amphibian habitats,...

Managing for No Net Loss of Ecological Services: An Approach for Quantifying Loss of Coastal Wetlands due to Sea Level Rise.

Science.gov (United States)

Kassakian, Jennifer; Jones, Ann; Martinich, Jeremy; Hudgens, Daniel

2017-05-01

Sea level rise has the potential to substantially alter the extent and nature of coastal wetlands and the critical ecological services they provide. In making choices about how to respond to rising sea level, planners are challenged with weighing easily quantified risks (e.g., loss of property value due to inundation) against those that are more difficult to quantify (e.g., loss of primary production or carbon sequestration services provided by wetlands due to inundation). Our goal was to develop a cost-effective, appropriately-scaled, model-based approach that allows planners to predict, under various sea level rise and response scenarios, the economic cost of wetland loss-with the estimates proxied by the costs of future restoration required to maintain the existing level of wetland habitat services. Our approach applies the Sea Level Affecting Marshes Model to predict changes in wetland habitats over the next century, and then applies Habitat Equivalency Analysis to predict the cost of restoration projects required to maintain ecological services at their present, pre-sea level rise level. We demonstrate the application of this approach in the Delaware Bay estuary and in the Indian River Lagoon (Florida), and discuss how this approach can support future coastal decision-making.

New Orleans to Venice, Louisiana. Hurricane Protection Project. Appendixes.

Science.gov (United States)

1985-03-01

or Fill Material. (1) General Characteristics of Material. The primary construction materials are clays and sands. Soil borings disclose that * - clay...Vegetation, water and soil characteristics of the Louisiana coastal region. Louisiana State University Agricultural Experiment Station Bulletin 664. 72pp...caused by pesticide accumulation through the food chain. It appears that high residue levels, especially of dieldrin, have resulted in thin eggshells

Louisiana ESI: PARISH (Parish Management Area Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains boundaries for parishes in coastal Louisiana. Vector polygons in this data set represent parish management areas. Location-specific type and...

Effects of Spartina alterniflora invasion on biogenic elements in a subtropical coastal mangrove wetland.

Science.gov (United States)

Yu, Xiaoqing; Yang, Jun; Liu, Lemian; Tian, Yuan; Yu, Zheng

2015-02-01

The invasion by exotic cordgrass (Spartina alterniflora) has become one of the most serious and challenging environmental and ecological problems in coastal China because it can have adverse effects on local native species, thereby changing ecosystem processes, functions, and services. In this study, 300 surface sediments were collected from 15 stations in the Jiulong River Estuary, southeast China, across four different seasons, in order to reveal the spatiotemporal variability of biogenic elements and their influencing factors in the subtropical coastal mangrove wetland. The biogenic elements including carbon, nitrogen, and sulfur (C, N, and S) were determined by an element analyzer, while the phosphorus (P) was determined by a flow injection analyzer. The concentrations of biogenic elements showed no significant differences among four seasons except total phosphorus (TP); however, our ANOVA analyses revealed a distinct spatial pattern which was closely related with the vegetation type and tidal level. Values of total carbon (TC) and total nitrogen (TN) in the surface sediment of mangrove vegetation zones were higher than those in the cordgrass and mudflat zones. The concentrations of TC, TN, TP, and total sulfur (TS) in the high tidal zones were higher than those in the middle and low tidal zones. Redundancy analysis (RDA) revealed that tidal level, vegetation type, and season had some significant influence on the distribution of biogenic elements in the Jiulong River Estuary, by explaining 18.2, 7.7, and 4.9 % of total variation in the four biogenic elements, respectively. In conclusion, S. alterniflora invasion had substantial effects on the distributions of biogenic elements in the subtropical coastal wetland. If regional changes in the Jiulong River Estuary are to persist and much of the mangrove vegetation was to be replaced by cordgrass, there would be significant decreases on the overall storage of C and N in this coastal zone. Therefore, the native

Defining restoration targets for water depth and salinity in wind-dominated Spartina patens (Ait.) Muhl. coastal marshes

Science.gov (United States)

Nyman, J.A.; LaPeyre, Megan K.; Caldwell, Andral W.; Piazza, Sarai C.; Thom, C.; Winslow, C.

2009-01-01

Coastal wetlands provide valued ecosystem functions but the sustainability of those functions often is threatened by artificial hydrologic conditions. It is widely recognized that increased flooding and salinity can stress emergent plants, but there are few measurements to guide restoration, management, and mitigation. Marsh flooding can be estimated over large areas with few data where winds have little effect on water levels, but quantifying flooding requires hourly measurements over long time periods where tides are wind-dominated such as the northern Gulf of Mexico. Estimating salinity of flood water requires direct daily measurements because coastal marshes are characterized by dynamic salinity gradients. We analyzed 399,772 hourly observations of water depth and 521,561 hourly observations of water salinity from 14 sites in Louisiana coastal marshes dominated by Spartina patens (Ait.) Muhl. Unlike predicted water levels, observed water levels varied monthly and annually. We attributed those observed variations to variations in river runoff and winds. In stable marshes with slow wetland loss rates, we found that marsh elevation averaged 1 cm above mean high water, 15 cm above mean water, and 32 cm above mean low water levels. Water salinity averaged 3.7 ppt during April, May, and June, and 5.4 ppt during July, August, and September. The daily, seasonal, and annual variation in water levels and salinity that were evident would support the contention that such variation be retained when designing and operating coastal wetland management and restoration projects. Our findings might be of interest to scientists, engineers, and managers involved in restoration, management, and restoration in other regions where S. patens or similar species are common but local data are unavailable.

Responses of Isolated Wetland Herpetofauna to Upland Forest Management

International Nuclear Information System (INIS)

Russell, K.R.; Hanlin, H.G.; Wigley, T.B.; Guynn, D.C. Jr.

2002-01-01

Measurement of responses of herpetofauna at isolated wetlands in the Coastal Plain of South Carolina to disturbance of adjacent loblolly pine forest. Many species of isolated wetland herpetofauna in the Southeastern Coastal Plain may tolerate some disturbance in adjacent upland stands. Responses of isolated wetland herpetofauna to upland silviculture and the need for adjacent forested buffers likely depend on the specific landscape context in which the wetlands occur and composition of the resident herpetofaunal community

Characterization of labile organic carbon in coastal wetland soils of the Mississippi River deltaic plain: Relationships to carbon functionalities

Energy Technology Data Exchange (ETDEWEB)

Dodla, Syam K. [School of Plant, Environmental and Soil Sciences, Louisiana State Univ. Agricultural Center, Baton Rouge, LA 70803 (United States); Wang, Jim J., E-mail: jjwang@agcenter.lsu.edu [School of Plant, Environmental and Soil Sciences, Louisiana State Univ. Agricultural Center, Baton Rouge, LA 70803 (United States); DeLaune, Ronald D. [Department of Oceanography and Coastal Sciences, School of the Coast and Environment, Louisiana State University, Baton Rouge, LA 70803 (United States)

2012-10-01

Adequate characterization of labile organic carbon (LOC) is essential to the understanding of C cycling in soil. There has been very little evaluation about the nature of LOC characterizations in coastal wetlands, where soils are constantly influenced by different redox fluctuations and salt water intrusions. In this study, we characterized and compared LOC fractions in coastal wetland soils of the Mississippi River deltaic plain using four different methods including 1) aerobically mineralizable C (AMC), 2) cold water extractable C (CWEC), 3) hot water extractable C (HWEC), and 4) salt extractable C (SEC), as well as acid hydrolysable C (AHC) which includes both labile and slowly degradable organic C. Molecular organic C functional groups of these wetland soils were characterized by {sup 13}C solid-state nuclear magnetic resonance (NMR). The LOC and AHC increased with soil organic C (SOC) regardless of wetland soil type. The LOC estimates by four different methods were positively and significantly linearly related to each other (R{sup 2} = 0.62-0.84) and with AHC (R{sup 2} = 0.47-0.71). The various LOC fractions accounted for {<=} 4.3% of SOC whereas AHC fraction represented 16-49% of SOC. AMC was influenced positively by O/N-alkyl and carboxyl C but negatively by alkyl C, whereas CWEC and SEC fractions were influenced only positively by carboxyl C but negatively by alkyl C in SOC. On the other hand, HWEC fraction was found to be only influenced positively by carbonyl C, and AHC positively by O/N-alkyl and alkyl C but negatively by aromatic C groups in SOC. Overall these relations suggested different contributions of various molecular organic C moieties to LOC in these wetlands from those often found for upland soils. The presence of more than 50% non-acid hydrolysable C suggested the dominance of relatively stable SOC pool that would be sequestered in these Mississippi River deltaic plain coastal wetland soils. The results have important implications to the

Development of an indicator to monitor mediterranean wetlands.

Science.gov (United States)

Sanchez, Antonio; Abdul Malak, Dania; Guelmami, Anis; Perennou, Christian

2015-01-01

Wetlands are sensitive ecosystems that are increasingly subjected to threats from anthropogenic factors. In the last decades, coastal Mediterranean wetlands have been suffering considerable pressures from land use change, intensification of urban growth, increasing tourism infrastructure and intensification of agricultural practices. Remote sensing (RS) and Geographic Information Systems (GIS) techniques are efficient tools that can support monitoring Mediterranean coastal wetlands on large scales and over long periods of time. The study aims at developing a wetland indicator to support monitoring Mediterranean coastal wetlands using these techniques. The indicator makes use of multi-temporal Landsat images, land use reference layers, a 50m numerical model of the territory (NMT) and Corine Land Cover (CLC) for the identification and mapping of wetlands. The approach combines supervised image classification techniques making use of vegetation indices and decision tree analysis to identify the surface covered by wetlands at a given date. A validation process is put in place to compare outcomes with existing local wetland inventories to check the results reliability. The indicator´s results demonstrate an improvement in the level of precision of change detection methods achieved by traditional tools providing reliability up to 95% in main wetland areas. The results confirm that the use of RS techniques improves the precision of wetland detection compared to the use of CLC for wetland monitoring and stress the strong relation between the level of wetland detection and the nature of the wetland areas and the monitoring scale considered.

Quantifying Sediment Characteristics and Infilling Rate within a Ship Shoal Dredge Borrow Area, Offshore Louisiana

Science.gov (United States)

Xue, Z.; Wilson, C.; Bentley, S. J.; Xu, K.; Liu, H.; Li, C.; Miner, M. D.

2017-12-01

Barrier islands provide protection to interior wetlands and maintain estuarine gradients. Mississippi River delta plain barrier islands are undergoing rapid disintegration due to high rates of subsidence and a deficit in the coastal sand supply. To mitigate for barrier island land loss, Louisiana has implemented a restoration program that intends to supplement coastal sand deficits by introducing sand from outside of the active coastal system. Inner-shelf shoals offshore Louisiana are one of the only sand resource options containing large volumes of restoration quality sand. Ship Shoal is one of these inner-shelf shoals that was produced by marine reworking of former Mississippi River Delta barrier island sediments during late Holocene time. Though indirect effects to protected areas or infrastructure adjacent to excavations have been considered, there is a paucity of observational data on their evolution. Caminada borrow area, dredged in 2013-2016 for the Caminada Headland Restoration Project, provides a valuable opportunity to validate and improve predictive models for how borrow areas evolve. In July 2017, a subbottom and bathymetric geophysical survey was conducted and sediment cores were collected to test the hypothesis that sedimentation within the excavation is affected by lateral bedload transport after initial rapid infill as slopes equilibrate. Preliminary results show the sediment within the excavation is predominantly very fine sand with isolated mud drapes. These sediments overlay older delta complex muddy strata. This contrasts strongly with other dredge pits outside of shoal areas and closer to shore, which have been infilled largely by advection of fine suspended sediments of fluvial origin. Laboratory work on cores will include laser grain size, x-ray analyses of sedimentary structures, and radiochemistry analyses for rates and age of deposition. With the knowledge of stratigraphy and sediment dynamics surrounding the dredge pit, we can quantify

Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Atlantic and Gulf Coastal Plain Region (Version 2.0)

Science.gov (United States)

2010-11-01

35 Figure 4. At the toe of a hill slope, the gradient is only slightly inclined or nearly level. ..................... 35...marshes, beach/ dune systems, and wet flats are typical of the outer coastal plain on recent or Holocene sediments, while mixed evergreen/hardwood...mangrove shrublands are also found along the Texas and Louisiana coasts (NatureServe 2006). Beach/ dune systems are typically associated with barrier

Analysis of environmental constraints on expanding reserves in current and future reservoirs in wetlands. Final report

Energy Technology Data Exchange (ETDEWEB)

Harder, B.J.

1995-03-01

Louisiana wetlands require careful management to allow exploitation of non-renewable resources without destroying renewable resources. Current regulatory requirements have been moderately successful in meeting this goal by restricting development in wetland habitats. Continuing public emphasis on reducing environmental impacts of resource development is causing regulators to reassess their regulations and operators to rethink their compliance strategies. We examined the regulatory system and found that reducing the number of applications required by going to a single application process and having a coherent map of the steps required for operations in wetland areas would reduce regulatory burdens. Incremental changes can be made to regulations to allow one agency to be the lead for wetland permitting at minimal cost to operators. Operators need cost effective means of access that will reduce environmental impacts, decrease permitting time, and limit future liability. Regulators and industry must partner to develop incentive based regulations that can provide significant environmental impact reduction for minimal economic cost. In addition regulators need forecasts of future E&P trends to estimate the impact of future regulations. To determine future activity we attempted to survey potential operators when this approach was unsuccessful we created two econometric models of north and south Louisiana relating drilling activity, success ratio, and price to predict future wetland activity. Results of the econometric models indicate that environmental regulations have a small but statistically significant effect on drilling operations in wetland areas of Louisiana. We examined current wetland practices and evaluated those practices comparing environmental versus economic costs and created a method for ranking the practices.

Characterization and modeling of sediment settling, consolidation, and suspension to optimize coastal Louisiana restoration

Science.gov (United States)

Sha, X.; Xu, K.; Bentley, S. J.; Robichaux, P. A.

2018-04-01

Many research efforts have been undertaken over many decades in the field of Louisiana coastal restoration, but long-term experiments for sediment suspension and consolidation in diversion-receiving basins are still limited, despite significance of this topic to ongoing restoration strategies. Sediment samples were collected from two active diversions on the Mississippi River: West Bay, a semi-enclosed bay located on the Mississippi River Delta and fed by the West Bay Diversion, and from Big Mar pond, a receiving basin of the Caernarvon freshwater diversion from the lower Mississippi River, Louisiana, USA. A dual-core Gust Erosion Microcosm System was used to measure time-series (0.5, 1, 2, 3, 4, 5, and 6-months after initial settling) erodibility at seven shear stress regimes (0.01-0.60 Pa) using experimental cores prepared with two initial sediment concentrations (60 and 120 kg m-3). A 230-cm tall settling column with nine sampling ports was used to measure the consolidation rates for initial sediment concentrations ranging from fluid mud (10 kg m-3) to dredge effluent (120 kg m-3), in combination with two levels of salinity (1 and 5). The erodibility of West Bay sediment decreased with increasing time of consolidation. The critical shear stress for resuspension increased from 0.2 Pa after 2 months to 0.45 Pa after 4 months of consolidation. The consolidation rates were inversely and exponentially related to initial sediment concentrations. Consolidation tests in salinity of 1 generally settled faster than that in salinity of 5, and consolidation tests with low sediment concentration tests generally settled faster than high-concentration tests. An exponential coefficient was added in the Sanford (2008) model to better predict the consolidation profile of both rapid early settling and slow self-weight consolidation processes. Our study suggests that enclosed basin, low salinity, relatively low sediment concentration and minimized disturbance for 4 months all favor

Blue Carbon Sequestration in Florida Coastal Wetlands - Response to Recent Climate Change and Holocene Climate Variability

Science.gov (United States)

Vaughn, D.; Bianchi, T. S.; Osborne, T.; Shields, M. R.; Kenney, W.

2017-12-01

Intertidal forests and salt marshes represent a major component of Florida's coasts and are essential to the health and integrity of coastal Florida's ecological and economic systems. In addition, coastal wetlands have been recognized as highly efficient carbon sinks with their ability to store carbon on time scales from centuries to millennia. Although losses of salt marshes, mangroves, and seagrass beds through both natural and anthropogenic forces are threatening their ability to act as carbon sinks globally, the poleward encroachment of mangroves into higher latitude salt marshes may lead to regional increases in carbon sequestration as mangroves store more carbon than salt marshes. For Florida, this encroachment of mangroves into salt marshes is prominent along the northern coasts where fewer freeze events have coincided with an increase in mangrove extent over the past several decades. Soil cores collected from a northeastern Florida wetland will allow us to determine whether the recent poleward encroachment of mangroves into northern Florida salt marshes has led to an increase in belowground carbon storage. The soil cores, which are approximately two to three meters in length, will also provide the first known record of carbon storage in a northern Florida wetland during the Holocene. Initial results from the top 40 cm, which represents 100 years based on dating of other northern Florida wetland cores, suggest more carbon is currently being stored within the transition between marsh and mangrove than in areas currently covered by salt marsh vegetation or mangroves. The transitional zone also has a much larger loss of carbon within the top 40 cm compared to the mangrove and marsh cores. Lignin-based degradation indices along with other biomarker data and 210Pb/137Cs ages will be presented to demonstrate how much of this loss of carbon may be related to degradation and how much may be related to changes in carbon sources.

Using Coupled Models to Study the Effects of River Discharge on Biogeochemical Cycling and Hypoxia in the Northern Gulf of Mexico

Science.gov (United States)

Penta, Bradley; Ko, D.; Gould, Richard W.; Arnone, Robert A.; Greene, R.; Lehrter, J.; Hagy, James; Schaeffer, B.; Murrell, M.; Kurtz, J.;

Landscape Evolution of the Oil Spill Mitigation Sand Berm in the Chandeleur Islands, Louisiana

Science.gov (United States)

2016-09-01

Survey (USGS) National Wetlands Research Center 700 Cajundome Boulevard Lafayette, LA 70506 Adrienne L. Garber University of Louisiana at Lafayette...amount of oil from reaching the Chandeleur Islands and inland wetlands ; thereby protecting these sensitive ecosystem resources. This study was...change from as- built to 360–day post-construction. The berm boundary represents the berm footprint above the -2 ft NAVD (Figure 2

Direct and indirect controls on organic matter decomposition in four coastal wetland communities along a landscape salinity gradient

Science.gov (United States)

Stagg, Camille L.; Baustian, Melissa M.; Perry, Carey L.; Carruthers, Tim J.B.; Hall, Courtney T.

2018-01-01

Coastal wetlands store more carbon than most ecosystems globally. As sea level rises, changes in flooding and salinity will potentially impact ecological functions, such as organic matter decomposition, that influence carbon storage. However, little is known about the mechanisms that control organic matter loss in coastal wetlands at the landscape scale. As sea level rises, how will the shift from fresh to salt-tolerant plant communities impact organic matter decomposition? Do long-term, plant-mediated, effects of sea-level rise differ from direct effects of elevated salinity and flooding?We identified internal and external factors that regulated indirect and direct pathways of sea-level rise impacts, respectively, along a landscape-scale salinity gradient that incorporated changes in wetland type (fresh, oligohaline, mesohaline and polyhaline marshes). We found that indirect and direct impacts of sea-level rise had opposing effects on organic matter decomposition.Salinity had an indirect effect on litter decomposition that was mediated through litter quality. Despite significant variation in environmental conditions along the landscape gradient, the best predictors of above- and below-ground litter decomposition were internal drivers, initial litter nitrogen content and initial litter lignin content respectively. Litter decay constants were greatest in the oligohaline marsh and declined with increasing salinity, and the fraction of litter remaining (asymptote) was greatest in the mesohaline marsh. In contrast, direct effects of salinity and flooding were positive. External drivers, salinity and flooding, stimulated cellulytic activity, which was highest in the polyhaline marsh.Synthesis. Our results indicate that as sea level rises, initial direct effects of salinity will stimulate decay of labile carbon, but over time as plant communities shift from fresh to polyhaline marsh, litter decay will decline, yielding greater potential for long-term carbon storage

Food Web Response to Habitat Restoration in Various Coastal Wetland Ecosystems

Science.gov (United States)

James, W. R.; Nelson, J. A.

2017-12-01

Coastal wetland habitats provide important ecosystem services, including supporting coastal food webs. These habitats are being lost rapidly. To combat the effects of these losses, millions of dollars have been invested to restore these habitats. However, the relationship between restoring habitat and restoring ecosystem functioning is poorly understood. Analyzing energy flow through food web comparisons between restored and natural habitats can give insights into ecosystem functioning. Using published stable isotope values from organisms in restored and natural habitats, we assessed the food web response of habitat restoration in salt marsh, mangrove, sea grass, and algal bed ecosystems. We ran Bayesian mixing models to quantify resource use by consumers and generated habitat specific niche hypervolumes for each ecosystem to assess food web differences between restored and natural habitats. Salt marsh, mangrove, and sea grass ecosystems displayed functional differences between restored and natural habitats. Salt marsh and mangrove food webs varied in the amount of each resource used, while the sea grass food web displayed more variation between individual organisms. The algal bed food web showed little variation between restored and natural habitats.

Effects of tidal cycles on shorebird distribution and foraging behaviour in a coastal tropical wetland: Insights for carrying capacity assessment

Science.gov (United States)

Fonseca, Juanita; Basso, Enzo; Serrano, David; Navedo, Juan G.

2017-11-01

Wetland loss has driven negative effects on biodiversity by a reduction in potential available habitats, directly impacting wetland-dependent species such as migratory shorebirds. At coastal areas where tidal cycles can restrict food access, the degree to which density of foraging birds is mediated by conspecific abundance or by the available areas is crucial to understanding patterns of bird distribution and wetland carrying capacity. We used the bathymetry of two sectors modeled with two numerical matrices to determine the availability of intertidal foraging areas in relation to tidal level (spring and neap tides), and this information was used to estimate shorebird density and foraging activity throughout the low-tide cycle in a tropical coastal lagoon in northwestern Mexico. Relative to spring tides, an 80% reduction in available foraging areas occurred during neap tides. Overall shorebird abundance was significantly reduced during neap tide periods, with differences between species. Densities of shorebirds increased during neap tides, particularly in one sector, and remained similar throughout the low-tide period (i.e. 4 h) either during spring or neap tides. Time spent foraging was consistently lower during neap-tides relative to spring-tides, especially for Long-billed curlew (44% reduction), Willet (37% reduction) and Black-necked stilt (29% reduction). These decreases in foraging activity when available habitats became reduced can hamper the opportunities of migratory shorebirds to reach their daily energy requirements to survive during the non-breeding season. This study shows that when intertidal habitats are severely reduced an important fraction of shorebird populations would probably be forced to find alternative areas to forage or increase foraging time during the night. Serving an essential function as top-predators, these results can have important implications on carrying capacity assessment for shorebirds at coastal wetlands.

Dissolved organic matter dynamics in the oligo/meso-haline zone of wetland-influenced coastal rivers

Science.gov (United States)

Maie, Nagamitsu; Sekiguchi, Satoshi; Watanabe, Akira; Tsutsuki, Kiyoshi; Yamashita, Youhei; Melling, Lulie; Cawley, Kaelin M.; Shima, Eikichi; Jaffé, Rudolf

2014-08-01

Wetlands are key components in the global carbon cycle and export significant amounts of terrestrial carbon to the coastal oceans in the form of dissolved organic carbon (DOC). Conservative behavior along the salinity gradient of DOC and chromophoric dissolved organic matter (CDOM) has often been observed in estuaries from their freshwater end-member (salinity = 0) to the ocean (salinity = 35). While the oligo/meso-haline (salinity DOC and CDOM optical properties determined by UV absorbance at 254 nm (A254) and excitation-emission matrix (EEM) fluorescence coupled with parallel factor analysis (PARAFAC) along the lower salinity range (salinity DOC and A254 was observed, while these parameters showed similar conservative behavior for the third. Three distinct EEM-PARAFAC models established for each of the rivers provided similar spectroscopic characteristics except for some unique fluorescence features observed for the Judan River. The distribution patterns of PARAFAC components suggested that the inputs from plankton and/or submerged aquatic vegetation can be important in the Bekanbeushi River. Further, DOM photo-products formed in the estuarine lake were also found to be transported upstream. In the Harney River, whereas upriver-derived terrestrial humic-like components were mostly distributed conservatively, some of these components were also derived from mangrove inputs in the oligo/meso-haline zone. Interestingly, fluorescence intensities of some terrestrial humic-like components increased with salinity for the Judan River possibly due to changes in the dissociation state of acidic functional groups and/or increase in the fluorescence quantum yield along the salinity gradient. The protein-like and microbial humic-like components were distributed differently between three wetland rivers, implying that interplay between loss to microbial degradation and inputs from diverse sources are different for the three wetland-influenced rivers. The results presented here

Assessment of Mud-Capped Dredge Pit Evolution Offshore Louisiana: Implications to Sand Excavation and Coastal Restoration

Science.gov (United States)

Xu, K.; Miner, M. D.; Bentley, S. J.; Li, C.; Obelcz, J.; O'Connor, M. C.

2016-02-01

The shelf offshore Louisiana is characterized by a dominantly muddy seafloor with a paucity of restoration-quality sand proximal to shore. Discrete sand deposits associated with ancient rivers that incised the shelf during lower sea-level positions occur close to shore. These shelf channel sands have been targeted for coastal restoration projects resulting in significant cost savings over more distal deposits. Several recent projects targeted shelf paleo-fluvial deposits comprising relatively deep (10 m) channel sands underlying a muddy overburden. Because of contrasting characteristics of cohesive mud vs. non-cohesive sand and potential modern fluvial mud supply from the Mississippi and Atchafalaya Rivers, long term pit evolution is poorly understood relative to their more common sand-only counterparts. Alterations to seafloor topography from dredging shelf sediment resources can potentially affect oil and gas infrastructure or other resources of concern (i.e. historic shipwrecks) located proximal to dredge pits. Site-specific data required to make accurate predictions and empirical measurements to test and validate predictive models were only available for Peveto Channel offshore Holly Beach, Louisiana. Here we present new geophysical and geological data (bathymetry, sidescan, subbottom, and radionuclide of sediment cores) and physical oceanographic observations (hydrodynamics and sediment dynamics) collected at Raccoon Island (dredged in 2013) dredge pit in Louisiana. These field data collections along with pre-existing data provide a time-series to capture evolution at Raccoon Island post-excavation. Conceptual morphological models will be developed for dredge pit evolution and testing effectiveness of setback buffers protecting pipelines, habitats, and cultural resources. Our results will increase decision making ability regarding safety and protecting environmental and cultural resources, and better management of valuable sand resources.

Flora characteristics of Chenier Wetland in Bohai Bay and biogeographic relations with adjacent wetlands

Science.gov (United States)

Zhao, Yanyun; Lu, Zhaohua; Liu, Jingtao; Hu, Shugang

2017-12-01

A key step towards the restoration of heavily disturbed fragile coastal wetland ecosystems is determining the composition and characteristics of the plant communities involved. This study determined and characterized the community of higher plants in the Chenier wetland of Bohai Bay using a combination of field surveys, quadrat approaches, and multivariate statistical analyses. This community was then compared to other adjacent wetlands (Tianjin, Qinhuangdao, Laizhouwan, Jiaozhouwan, and Yellow River Delta wetland) located near the Huanghai and Bohai Seas using principal coordinate analysis (PCoA). Results showed a total of 56 higher plant species belonging to 52 genera from 20 families in Chenier wetland, the majority of which were dicotyledons. Single-species families were predominant, while larger families, including Gramineae, Compositae, Leguminosae, and Chenopodiaceae contained a higher number of species (each⩾6 species). Cosmopolitan species were also dominant with apparent intrazonality. Abundance (number of species) of temperate species was twice that of tropical taxa. Species number of perennial herbs, such as Gramineae and Compositae, was generally higher. Plant diversity in the Chenier wetland, based on the Shannon-Wiener index, was observed to be between the Qinhuangdao and Laizhouwan indices, while no significant difference was found in other wetlands using the Simpson index. Despite these slight differences in diversity, PCoA based on species abundance and composition of the wetland flora suggest that the Bohai Chenier community was highly similar to the coastal wetlands in Tianjin and Laizhouwan, further suggesting that these two wetlands could be important breeding grounds and resources for the restoration of the plant ecosystem in the Chenier wetland.

Ecosystem level methane fluxes from tidal freshwater and brackish marshes of the Mississippi River Delta: Implications for coastal wetland carbon projects

Science.gov (United States)

Holm, Guerry O.; Perez, Brian C.; McWhorter, David E.; Krauss, Ken W.; Johnson, Darren J.; Raynie, Richard C.; Killebrew, Charles J.

2016-01-01

Sulfate from seawater inhibits methane production in tidal wetlands, and by extension, salinity has been used as a general predictor of methane emissions. With the need to reduce methane flux uncertainties from tidal wetlands, eddy covariance (EC) techniques provide an integrated methane budget. The goals of this study were to: 1) establish methane emissions from natural, freshwater and brackish wetlands in Louisiana based on EC; and 2) determine if EC estimates conform to a methane-salinity relationship derived from temperate tidal wetlands with chamber sampling. Annual estimates of methane emissions from this study were 62.3 g CH4/m2/yr and 13.8 g CH4/m2/yr for the freshwater and brackish (8–10 psu) sites, respectively. If it is assumed that long-term, annual soil carbon sequestration rates of natural marshes are ~200 g C/m2/yr (7.3 tCO2e/ha/yr), healthy brackish marshes could be expected to act as a net radiative sink, equivalent to less than one-half the soil carbon accumulation rate after subtracting methane emissions (4.1 tCO2e/ha/yr). Carbon sequestration rates would need case-by-case assessment, but the EC methane emissions estimates in this study conformed well to an existing salinity-methane model that should serve as a basis for establishing emission factors for wetland carbon offset projects.

Post-Hurricane Isaac coastal oblique aerial photographs collected along the Alabama, Mississippi, and Louisiana barrier islands, September 2–3, 2012

Science.gov (United States)

Morgan, Karen L. M.; Karen A. Westphal,

2016-04-21

The U.S. Geological Survey (USGS), as part of the National Assessment of Coastal Change Hazards project, conducts baseline and storm-response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms (Morgan, 2009). On September 2-3, 2012, the USGS conducted an oblique aerial photographic survey along the Alabama, Mississippi, and Louisiana barrier islands aboard a Cessna 172 (aircraft) at an altitude of 500 feet (ft) and approximately 1,000 ft offshore. This mission was flown to collect post-Hurricane Isaac data for assessing incremental changes in the beach and nearshore area since the last survey, flown in September 2008 (central Louisiana barrier islands) and June 2011 (Dauphin Island, Alabama, to Breton Island, Louisiana), and the data can be used in the assessment of future coastal change.The photographs provided in this report are Joint Photographic Experts Group (JPEG) images. ExifTool was used to add the following to the header of each photo: time of collection, Global Positioning System (GPS) latitude, GPS longitude, keywords, credit, artist (photographer), caption, copyright, and contact information. The photograph locations are an estimate of the position of the aircraft at the time the photograph was taken and do not indicate the location of any feature in the images (see the Navigation Data page). These photographs document the state of the barrier islands and other coastal features at the time of the survey. Pages containing thumbnail images of the photographs, referred to as contact sheets, were created in 5-minute segments of flight time. These segments can be found on the Photos and Maps page. Photographs can be opened directly with any JPEG-compatible image viewer by clicking on a thumbnail on the contact sheet.In addition to the photographs, a Google Earth Keyhole Markup Language (KML) file is provided and can be used to view the images by clicking on the marker and then clicking on

78 FR 32237 - Draft Initial Comprehensive Plan and Draft Programmatic Environmental Assessment

Science.gov (United States)

2013-05-29

...), which is chaired by the Secretary of Commerce and includes the Governors of Alabama, Florida, Louisiana..., marine and wildlife habitats, beaches, coastal wetlands, and economy of the Gulf Coast region...

Vegetation cover, tidal amplitude and land area predict short-term marsh vulnerability in Coastal Louisiana

Science.gov (United States)

Schoolmaster, Donald; Stagg, Camille L.; Sharp, Leigh Anne; McGinnis, Tommy S.; Wood, Bernard; Piazza, Sarai

2018-01-01

The loss of coastal marshes is a topic of great concern, because these habitats provide tangible ecosystem services and are at risk from sea-level rise and human activities. In recent years, significant effort has gone into understanding and modeling the relationships between the biological and physical factors that contribute to marsh stability. Simulation-based process models suggest that marsh stability is the product of a complex feedback between sediment supply, flooding regime and vegetation response, resulting in elevation gains sufficient to match the combination of relative sea-level rise and losses from erosion. However, there have been few direct, empirical tests of these models, because long-term datasets that have captured sufficient numbers of marsh loss events in the context of a rigorous monitoring program are rare. We use a multi-year data set collected by the Coastwide Reference Monitoring System (CRMS) that includes transitions of monitored vegetation plots to open water to build and test a predictive model of near-term marsh vulnerability. We found that despite the conclusions of previous process models, elevation change had no ability to predict the transition of vegetated marsh to open water. However, we found that the processes that drive elevation change were significant predictors of transitions. Specifically, vegetation cover in prior year, land area in the surrounding 1 km2 (an estimate of marsh fragmentation), and the interaction of tidal amplitude and position in tidal frame were all significant factors predicting marsh loss. This suggests that 1) elevation change is likely better a predictor of marsh loss at time scales longer than we consider in this study and 2) the significant predictive factors affect marsh vulnerability through pathways other than elevation change, such as resistance to erosion. In addition, we found that, while sensitivity of marsh vulnerability to the predictive factors varied spatially across coastal Louisiana

Discrimination of coastal wetland environments in the Amazon region based on multi-polarized L-band airborne Synthetic Aperture Radar imagery

Science.gov (United States)

Souza-Filho, Pedro Walfir M.; Paradella, Waldir R.; Rodrigues, Suzan W. P.; Costa, Francisco R.; Mura, José C.; Gonçalves, Fabrício D.

2011-11-01

This study assessed the use of multi-polarized L-band images for the identification of coastal wetland environments in the Amazon coast region of northern Brazil. Data were acquired with a SAR R99B sensor from the Amazon Surveillance System (SIVAM) on board a Brazilian Air Force jet. Flights took place in the framework of the 2005 MAPSAR simulation campaign, a German-Brazilian feasibility study focusing on a L-band SAR satellite. Information retrieval was based on the recognition of the interaction between a radar signal and shallow-water morphology in intertidal areas, coastal dunes, mangroves, marshes and the coastal plateau. Regarding the performance of polarizations, VV was superior for recognizing intertidal area morphology under low spring tide conditions; HH for mapping coastal environments covered with forest and scrub vegetation such as mangrove and vegetated dunes, and HV was suitable for distinguishing transition zones between mangroves and coastal plateau. The statistical results for the classification maps expressed by kappa index and general accuracy were 83.3% and 0.734 for the multi-polarized color composition (R-HH, G-HV, B-VV), 80.7% and 0.694% for HH, 79.7% and 0.673% for VV, and 77.9% and 0.645% for HV amplitude image. The results indicate that use of multi-polarized L-band SAR is a valuable source of information aiming at the identification and discrimination of distinct geomorphic targets in tropical wetlands.

Seasonal movements and multiscale habitat selection of Whooping Crane (Grus americana) in natural and agricultural wetlands

Science.gov (United States)

Pickens, Bradley A.; King, Sammy L.; Vasseur, Phillip L.; Zimorski, Sara E.; Selman, Will

2017-01-01

Eleven of 15 species of cranes (family: Gruidae) are considered vulnerable or endangered, and the increase of agriculture and aquaculture at the expense of natural wetlands and grasslands is a threat to Gruidae worldwide. A reintroduced population of Whooping Crane (Grus americana) was studied in coastal and agricultural wetlands of Louisiana and Texas, USA. The objectives were to compare Whooping Crane movements across seasons, quantify multiscale habitat selection, and identify seasonal shifts in selection. Whooping Cranes (n = 53) were tracked with satellite transmitters to estimate seasonal core-use areas (50% home range contours) via Brownian bridge movement models and assess habitat selection. Whooping Crane core-use areas (n = 283) ranged from 4.7 to 438.0 km2, and habitat selection changed seasonally as shallow water availability varied. Whooping Crane core-use areas were composed of more fresh marsh in spring/summer, but shifted towards rice and crawfish (Procambarus spp.) aquaculture in the fall/winter. Within core-use areas, aquaculture was most strongly selected, particularly in fall when fresh marsh became unsuitable. Overall, the shifting of Whooping Crane habitat selection over seasons is likely to require large, heterogeneous areas. Whooping Crane use of agricultural and natural wetlands may depend on spatio-temporal dynamics of water depth.

Wetlands of the Gulf Coast

Science.gov (United States)

2001-01-01

This set of images from the Multi-angle Imaging SpectroRadiometer highlights coastal areas of four states along the Gulf of Mexico: Louisiana, Mississippi, Alabama and part of the Florida panhandle. The images were acquired on October 15, 2001 (Terra orbit 9718)and represent an area of 345 kilometers x 315 kilometers.The two smaller images on the right are (top) a natural color view comprised of red, green, and blue band data from MISR's nadir(vertical-viewing) camera, and (bottom) a false-color view comprised of near-infrared, red, and blue band data from the same camera. The predominantly red color of the false-color image is due to the presence of vegetation, which is bright at near-infrared wavelengths. Cities appear as grey patches, with New Orleans visible at the southern edge of Lake Pontchartrain, along the left-hand side of the images. The Lake Pontchartrain Bridge runs approximately north-south across the middle of the lake. The distinctive shape of the Mississippi River Delta can be seen to the southeast of New Orleans. Other coastal cities are visible east of the Mississippi, including Biloxi, Mobile and Pensacola.The large image is similar to the true-color nadir view, except that red band data from the 60-degree backward-looking camera has been substituted into the red channel; the blue and green data from the nadir camera have been preserved. In this visualization, green hues appear somewhat subdued, and a number of areas with a reddish color are present, particularly near the mouths of the Mississippi, Pascagoula, Mobile-Tensaw, and Escambia Rivers. Here, the red color is highlighting differences in surface texture. This combination of angular and spectral information differentiates areas with aquatic vegetation associated with poorly drained bottom lands, marshes, and/or estuaries from the surrounding surface vegetation. These wetland regions are not as well differentiated in the conventional nadir views.Variations in ocean color are apparent in

Pipeline corridors through wetlands

International Nuclear Information System (INIS)

Zimmerman, R.E.; Wilkey, P.L.; Isaacson, H.R.

1992-01-01

This paper presents preliminary findings from six vegetational surveys of gas pipeline rights-of-way (ROW) through wetlands and quantifies the impacts of a 20-year-old pipeline ROW through a boreal forest wetland. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the Row approximated or exceeded those in the adjacent natural area. The boreal forest study showed that (1) adjacent natural wetland areas were not altered in type; (2) water sheet flow restriction had been reversed by nature; (3) no nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity

Gas Research Institute wetland research program

International Nuclear Information System (INIS)

Wilkey, P.L.; Zimmerman, R.E.; Isaacson, H.R.

1992-01-01

As part of three ongoing research projects, the Gas Research Institute (GRI) is studying the natural gas industry's impacts on wetlands and how to manage operations so that impacts can be minimized or eliminated. The objective of the first project is to gain a better understanding of the causes and processes of wetland loss in the Louisiana deltaic plain and what role gas pipeline canals play in wetland loss. On the basis of information gathered from the first projects, management and mitigation implications for pipeline construction and maintenance will be evaluated. The objective of the second project is to assess the floral and faunal communities on existing rights-of-way (ROWs) that pass through numerous types of wetlands across the United States. The emphasis of the project is on pipelines that were installed within the past five years. The objective of the third project is to evaluate the administrative, jurisdictional, technical, and economic issues of wetland mitigation banking. This paper discusses these projects, their backgrounds, some of the results to date, and the deliverables

Spatial an temporal analysis of chloride concentrations in underground water in the coastal wetland of l'Albufera, Spain

Science.gov (United States)

Puhakka, Evelina; Pascual-Aguilar, Juan Antonio; Andreu, Vicente

2010-05-01

Mediterranean coastal wetlands are of great interest for their richness in biodiversity. They are also fragile systems because they are exposed to various human pressures, such as farming systems and urban sprawl. Most Mediterranean coastal wetlands have a transient underground inter phase of continental and marine water. In many cases, the variations of the rain regime towards an increasing dryness and the overexploitation of aquiphers in these zones could favour the marine water intrusion, being a source of continental water salinisation and loss of its quality. This process can directly affect the ecosystems and produce loss of biodiversity. Thus, studies to assess the dynamics in time and space of the possible marine intrusion are necessary to evaluate coastal environment health and quality. The study has been applied to L'Albufera Natural Park, the largest Coastal Wetland in eastern Spain. Due to its importance, it has been included in the list of Wetlands of the RAMSAR Convention. In the area there is a complex relationship between the intrinsic natural importance (endemicity and biodiversity) and the human activities (traditional agriculture and hinterland industrial and settlement development). The methodological approach is based in the analysis of chloride concentrations time series of thirteen sample water points distributed in and around the boundaries of the Natural Park. All time series, between 1982 and 2008, have been analysed to establish trends both in time and space. Results show that in samples close to the see (between 1500 and 2000 metres) chloride concentrations are not too high, with values between 37 mg/l and 213 mg/l. Nonetheless, the shorter is the distance to the see the higher are the chloride levels, with values between 58 mg/l and 1131 mg/l. For longer distances, more than 2000 from the coast line, values are quite similar in most sample points, from 52 mg/l to 691 mg/l. Among all the thirteen time series analysed trends are detected

Measurement and modelling of evaporation from a coastal wetland in Maputaland, South Africa

Directory of Open Access Journals (Sweden)

A. D. Clulow

2012-09-01

Full Text Available The surface renewal (SR method was used to determine the long-term (12 months total evaporation (ET from the Mfabeni Mire with calibration using eddy covariance during two window periods of approximately one week each. The SR method was found to be inexpensive, reliable and with low power requirements for unattended operation.

Despite maximum ET rates of up to 6.0 mm day⁻¹, the average summer (October to March ET was lower (3.2 mm day⁻¹ due to early morning cloud cover that persisted until nearly midday at times. This reduced the daily available energy, and the ET was lower than expected despite the available water and high average wind speeds. In winter (May to September, there was less cloud cover but the average ET was only 1.8 mm day⁻¹ due to plant senescence. In general ET was suppressed by the inflow of humid air (low vapour pressure deficit and the comparatively low leaf area index of the wetland vegetation. The accumulated ET over 12 months was 900 mm. Daily ET estimates were compared to the Priestley-Taylor model results and a calibration α = 1.0 (R² = 0.96 was obtained for the site. A monthly crop factor (K_c was determined for the standardised FAO-56 Penman-Monteith. However, K_c was variable in some months and should be used with caution for daily ET modelling.

These results represent not only some of the first long-term measurements of ET from a wetland in southern Africa, but also one of the few studies of actual ET in a subtropical peatland in the Southern Hemisphere. The study provides wetland ecologists and hydrologists with guidelines for the use of two internationally applied models for the estimation of wetland ET within a coastal, subtropical environment and shows that wetlands are not necessarily high water users.

Spatial Patterns in Biogeochemical Processes During Peak Growing Season in Oiled and Unoiled Louisiana Salt Marshes: A Multi-Year Analysis

Science.gov (United States)

Chelsky, A.; Marton, J. M.; Bernhard, A. E.; Giblin, A. E.; Setta, S. P.; Hill, T. D.; Roberts, B. J.

2016-02-01

Louisiana salt marshes are important sites for carbon and nitrogen cycling because they can mitigate fluxes of nutrients and carbon to the Gulf of Mexico where a large hypoxic zone develops annually. The aim of this study was to investigate spatial and temporal patterns of biogeochemical processes in Louisiana coastal wetlands during peak growing season, and to investigate whether the Deepwater Horizon oil spill resulted in persistent changes to these rates. We measured nitrification potential and sediment characteristics at two pairs of oiled/unoiled marshes in three regions across the Louisiana coast (Terrebonne and east and west Barataria Bay) in July from 2012 to 2015, with plots along a gradient from the salt marsh edge to the interior. Rates of nitrification potential across the coast (overall mean of 901 ± 115 nmol gdw-1 d-1 from 2012-2014) were high compared to other published rates for salt marshes but displayed high variability at the plot level (4 orders of magnitude). Within each region interannual means varied by factors of 2-5. Nitrification potential did not differ with oiling history, but did display consistent spatial patterns within each region that corresponded to changes in relative elevation and inundation, which influence patterns of soil properties and microbial communities. In 2015, we also measured greenhouse gas (CO2, N2O and CH4) production and denitrification enzyme activity rates in addition to nitrification potential across the region to investigate spatial relationships between these processes.

Rapid Stable Isotope Turnover of Larval Fish in a Lake Superior Coastal Wetland: Implications for Diet and Life History Studies

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Trophic linkages of larval fish in Lake Superior coastal wetlands, rivers and embayments can be identified using naturally occurring differences in the stable isotope ratios of nitrogen (15N:14N, ?15N) and carbon (13C:12C, ?13C). We sampled pelagic fish larvae weekly during sprin...

Working group report on wetlands, wildlife and fisheries

International Nuclear Information System (INIS)

Maltby, L.

1990-01-01

A workshop was held to discuss the impacts of climatic change on wetlands, wildlife and fisheries. Impacts that could occur as a result of climatic change include: sea level rise affecting coastal wetlands by inundation, erosion and saltwater intrusion; temperature rise/moisture balance changes on other wetlands; lake level changes affecting shoreline wetlands; vegetation species/community modification of biological systems; and changes in values derived from wetlands impacting socio-economic systems. The Great Lakes shoreline is considered to be at high risk, and it is predicted that there will be profound effects on the ecological and socio-economic value of the Great Lakes wetlands. Presentations were given on wildlife as biological indicators, modelling the effects of climate warming on the stream habitats of brook trout, and the effects of an altered water regime on Great Lakes coastal wetlands. It was concluded that a fundamental research program of an interdisciplinary nature be established to determine current linkages of climatic variables to the function, distribution and productivity of wetlands and associated fish and wildlife resources. A national wetlands monitoring network should be established to trace the influence of climatic variables on wetlands and fish, to identify environmental indicators for reporting and to complement other monitoring programs

China's natural wetlands: past problems, current status, and future challenges

Science.gov (United States)

Shuqing An; Harbin Li; Baohua Guan; Changfang Zhou; Zhongsheng Wang; Zifa Deng; Yingbiao Zhi; Yuhong Liu; Chi Xu; Shubo Fang; Jinhui Jiang; Hongli Li

2007-01-01

Natural wetlands, occupying 3.8% of China's land and providing 54.9% of ecosystem services, are unevenly distributed among eight wetland regions. Natural wetlands in China suffered great loss and degradation (e.g., 23.0% freshwater swamps, 51.2% coastal wetlands) because of the wetland reclamation during China's long history of civilization, and the...

The surface elevation table and marker horizon technique: A protocol for monitoring wetland elevation dynamics

Science.gov (United States)

James C. Lynch,; Phillippe Hensel,; Cahoon, Donald R.

2015-01-01

The National Park Service, in response to the growing evidence and awareness of the effects of climate change on federal lands, determined that monitoring wetland elevation change is a top priority in North Atlantic Coastal parks (Stevens et al, 2010). As a result, the NPS Northeast Coastal and Barrier Network (NCBN) in collaboration with colleagues from the U.S. Geological Survey (USGS) and The National Oceanic and Atmospheric Administration (NOAA) have developed a protocol for monitoring wetland elevation change and other processes important for determining the viability of wetland communities. Although focused on North Atlantic Coastal parks, this document is applicable to all coastal and inland wetland regions. Wetlands exist within a narrow range of elevation which is influenced by local hydrologic conditions. For coastal wetlands in particular, local hydrologic conditions may be changing as sea levels continue to rise. As sea level rises, coastal wetland systems may respond by building elevation to maintain favorable hydrologic conditions for their survival. This protocol provides the reader with instructions and guidelines on designing a monitoring plan or study to: A) Quantify elevation change in wetlands with the Surface Elevation Table (SET). B) Understand the processes that influence elevation change, including vertical accretion (SET and Marker Horizon methods). C) Survey the wetland surface and SET mark to a common reference datum to allow for comparing sample stations to each other and to local tidal datums. D) Survey the SET mark to monitor its relative stability. This document is divided into two parts; the main body that presents an overview of all aspects of monitoring wetland elevation dynamics, and a collection of Standard Operating Procedures (SOP) that describes in detail how to perform or execute each step of the methodology. Detailed instruction on the installation, data collection, data management and analysis are provided in this report

Hydrographic and chemical water parameters collected by CTD and other instruments from the Pelican and the Tommy Munro in coastal waters of Louisiana from 1994-07-24 to 1997-07-29 (NCEI Accession 0164298)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Hydrographic and chemical data were collected for a week in late July between 1994-1997 in order to survey the coastal hypoxia on Louisiana continental shelf....

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from time series observations using Bubble type equilibrator for autonomous carbon dioxide (CO2) measurement, Carbon dioxide (CO2) gas analyzer and other instruments from MOORING CoastalMS_88W_30N in the Coastal Waters of Louisiana and Gulf of Mexico from 2009-05-12 to 2014-05-03 (NODC Accession 0100068)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0100068 includes chemical, meteorological, physical and time series data collected from MOORING CoastalMS_88W_30N in the Coastal Waters of Louisiana...

Modeling the impacts of climate variability and hurricane on carbon sequestration in a coastal forested wetland in South Carolina

Science.gov (United States)

Zhaohua Dai; Carl C. Trettin; Changsheng Li; Ge Sun; Devendra M. Amatya; Harbin Li

2013-01-01

The impacts of hurricane disturbance and climate variability on carbon dynamics in a coastal forested wetland in South Carolina of USA were simulated using the Forest-DNDC model with a spatially explicit approach. The model was validated using the measured biomass before and after Hurricane Hugo and the biomass inventories in 2006 and 2007, showed that the Forest-DNDC...

Assessment of the content, structure, and source of soil dissolved organic matter in the coastal wetlands of Jiaozhou Bay, China

Science.gov (United States)

Xi, Min; Zi, Yuanyuan; Wang, Qinggai; Wang, Sen; Cui, Guolu; Kong, Fanlong

2018-02-01

The contents and the spectral analysis of dissolved organic matter (DOM) in four typical wetlands, such as naked tidal, suaeda salsa, reed and spartina, were conducted to investigate the content, structure, and source of DOM in coastal wetland soil. The soil samples were obtained from Jiaozhou Bay in January, April, July, and October of 2014. Results showed that the DOM contents in soil of four typical wetland were in order of spartina wetland > naked tidal > suaeda salsa wetland > reed wetland in horizontal direction, and decreased with the increase of soil depth on vertical section. In addition, the DOM contents changed with the seasons, in order of spring > summer > autumn > winter. The structural characteristics of DOM in Jiaozhou Bay wetland, such as aromaticity, hydrophobicity, molecular weight, polymerization degree of benzene ring carbon frame structure and so on were in order of spartina wetland > naked tidal > suaeda salsa wetland > reed wetland in the horizontal direction. On the vertical direction, they showed a decreasing trend with the increase of soil depth. The results of three dimensional fluorescence spectra and fluorescence spectrum parameters (FI, HIX, and BIX) indicated that the DOM in Jiaozhou Bay was mainly derived from the biological activities. The contents and structure of DOM had certain relevance, but the contents and source as well as the structure and source of DOM had no significant correlation. The external pollution including domestic sewage, industrial wastewater, and aquaculture sewage affected the correlation among the content, structure and source of DOM by influencing the percentage of non-fluorescent substance in DOM and disturbing the determination of protein-like fluorescence.

Degradation State and Sequestration Potential of Carbon in Coastal Wetlands of Texas: Mangrove Vs. Saltmarsh Ecosystems

Science.gov (United States)

Sterne, A. M. E.; Kaiser, K.; Louchouarn, P.; Norwood, M. J.

2015-12-01

The estimated magnitude of the organic carbon (OC) stocks contained in the first meter of US coastal wetland soils represents ~10% of the entire OC stock in US soils (4 vs. 52 Pg, respectively). Because this stock extends to several meters below the surface for many coastal wetlands, it becomes paramount to understand the fate of OC under ecosystem shifts, varying natural environmental constraints, and changing land use. In this project we analyze the major classes of biochemicals including total hydrolysable neutral carbohydrates, enantiomeric amino acids, phenols, and cutins/suberins at two study sites located on the Texas coastline to investigate chemical composition and its controls on organic carbon preservation in mangrove (Avicennia germinans) and saltmarsh grass (Spartina alterniflora) dominated wetlands. Results show neutral carbohydrates and lignin contribute 30-70% and 10-40% of total OC, respectively, in plant litter and surface sediments at both sites. Sharp declines of carbohydrate yields with depth occur parallel to increasing Ac/AlS,V ratios indicating substantial decomposition of both the polysaccharide and lignin components of litter detritus. Contrasts in the compositions and relative abundances of all previously mentioned compound classes are further discussed to examine the role of litter biochemistry in OC preservation. For example, the selective preservation of cellulose over hemicellulose in sediments indicates macromolecular structure plays a key role in preservation between plant types. It is concluded that the chemical composition of litter material controls the composition and magnitude of OC stored in sediments. Ultimately, as these ecosystems transition from one dominant plant type to another, as is currently observed along the Texas coastline, there is the potential for OC sequestration efficiency to shift due to the changing composition of OC input to sediments.

Studying the impact of climate change on coastal aquifers and adjacent wetlands

Science.gov (United States)

Stigter, Tibor; Ribeiro, Luís.; Oliveira, Rodrigo; Samper, Javier; Fakir, Younes; Fonseca, Luís.; Monteiro, José Paulo; Nunes, João. Pedro; Pisani, Bruno

2010-05-01

program, assessing the impact of climate change on coastal groundwater resources and dependent ecosystems. These resources are often intensively exploited, potentially leading to saltwater intrusion and the degradation of groundwater and dependent wetlands. Climate change may increase this problem in Mediterranean regions, due to the combined effect of rising sea levels and decreasing aquifer recharge. CLIMWAT aims to address this problem by employing a multimethodological approach involving climate scenarios, surface and groundwater flow and transport modeling, as well as hydrochemical indicator and ecological diversity indices. Research is performed in three coastal areas: the Central Algarve in Portugal, the Ebro delta in Spain and the Atlantic Sahel in Morocco. The mean annual temperatures are 17.4 ° C, 17.2 ° C and 17.5 ° C, respectively, whereas mean annual rainfall is lower in the Atlantic Sahel (390 mm) than in the Ebro Delta (520 mm) and the Central Algarve (660 mm). Work package (WP) 1 involves the collection of existing data (in a GIS environment), baseline characterization and the selection of monitoring locations. These include wells and springs of official (water level/quality) monitoring networks, as well as additional observation points selected at strategic locations, including the wetlands receiving groundwater and adjacent aquifer sectors. In WP2 the climate scenarios are selected and integrated in hydrological models (SWAT, GISBALAN), which are developed and calibrated with existing data, prior to scenario modeling. The main focus of this WP is to estimate the evolution of surface runoff and groundwater recharge under climate change. Data on climate change scenarios and model projections are compiled from: (i) the PRUDENCE project; (ii) the ENSEMBLES project; (iii) IPCC scenarios and projections, AR4; (iv) AEMet (Spanish Meteorological Agency) for generation of regional scenarios of climate change in Spain. For Morocco, where runoff is

A conceptual approach to integrate management of ecosystem service and disservice in coastal wetlands

Directory of Open Access Journals (Sweden)

Jon Knight

2017-04-01

Full Text Available Management of coastal wetlands is increasingly difficult because of increasing pressure arising from anthropogenic causes. These include sea level and climate change as well as coastline development caused by population growth and demographic shifts, for example, amenity migration where people move to coastal communities for lifestyle reasons. Management of mangroves and salt marshes is especially difficult because maintaining ecosystem values, including the goods and services provided, is countered by the potential of enhancing or even creating ecosystem disservices, such as unpleasant odour and mosquito hazards. Here we present, explain and apply a conceptual model aimed at improving understanding of management choices that primarily focus on mitigation of disservice while enabling improvement in ecosystem services. The model was developed after more than 30 years of habitat management following modification of a salt marsh to control mosquito production. We discuss the application of the model in a mangrove forest known to produce mosquitoes and outline the benefits arising from using the model.

A comparison of resident fish assemblages in managed and unmanaged coastal wetlands in North Carolina and South Carolina

Science.gov (United States)

Robinson, Kelly F.; Jennings, Cecil A.

2014-01-01

The dominant fish species within impounded coastal wetlands in the southeastern US may be different from the species that dominate natural marshes. We tested the hypothesis that resident fish assemblages inhabiting impounded coastal wetlands in South Carolina would differ from resident assemblages in natural marshes of the southeastern United States. We used rarefied species richness, Shannon's H' diversity,J' evenness, Morisita's index of similarity, and the percent similarity index to compare resident fish assemblages from two impoundments to 12 open-marsh resident fish assemblages from previously published studies in North and South Carolina. We used rotenone to sample fish assemblages in impoundments. The assemblages in natural marsh habitat had been sampled with rotenone and seines. We classified comparisons yielding a similarity index ≥0.50 as moderately similar and those with an index ≥0.75 as very similar. Fifty-three percent of the among-impoundment comparisons (Morisita's index) were at least moderately similar, whereas 7% of impoundment—natural marsh comparisons were moderately similar. A difference in tidal influence was the only parameter in the best-fitting model describing the observed Morisita's indices. The index of similarity decreased by 63% when tidal influence differed between compared assemblages. Species richness and diversity were greater in impoundments than natural marshes, but evenness was similar between habitat types. Our results support the hypothesis that resident fish assemblages in impounded wetlands and natural marshes are different, and suggest that a degree of tidal influence is the most important factor behind the difference.

Seawater and Freshwater Circulations through Coastal Forested Wetlands on a Caribbean Island

Directory of Open Access Journals (Sweden)

Luc Lambs

2015-07-01

Full Text Available Structure and composition of coastal forested wetlands are mainly controlled by local topography and soil salinity. Hydrology plays a major role in relation with tides, seaward, and freshwater inputs, landward. We report here the results of a two-year study undertaken in a coastal plain of the Guadeloupe archipelago (FWI. As elsewhere in the Caribbean islands, the study area is characterized by a micro-tidal regime and a highly seasonal climate. This work aimed at understanding groundwater dynamics and origin (seawater/freshwater both at ecosystems and stand levels. These hydrological processes were assessed through 18O/16O and 2H/1H isotopic analyses, and from monthly monitoring of water level and soil salinity at five study sites located in mangrove (3 and swamp forest (2. Our results highlight the importance of freshwater budget imbalance during low rainfall periods. Sustained and/or delayed dry seasons cause soil salinity to rise at the mangrove/swamp forest ecotone. As current models on climate change project decreasing rainfall amounts over the inner Caribbean region, one may expect for this area an inland progression of the mangrove forest to the expense of the nearby swamp forest.

New Orleans to Venice, Louisiana Hurricane Protection Project, Draft Supplemental Environmental Impact Statement. Appendixes.

Science.gov (United States)

1984-02-01

General Characteristics of Material. The primary " construction materials are clays and sands. Soil borings disclose that the clay to be removed from the...Chabreck, Robert. 1972. Vegetation, water and soil characteristics of the Louisiana coastal region. Louisiana State University Agricultural ,. Experiment...levels, especially of dieldrin, have resulted in thin eggshells . Other factors affecting the population are shooting, elec- trocution, severe weather

A Carbon Monitoring System Approach to US Coastal Wetland Carbon Fluxes: Progress Towards a Tier II Accounting Method with Uncertainty Quantification

Science.gov (United States)

Windham-Myers, L.; Holmquist, J. R.; Bergamaschi, B. A.; Byrd, K. B.; Callaway, J.; Crooks, S.; Drexler, J. Z.; Feagin, R. A.; Ferner, M. C.; Gonneea, M. E.; Kroeger, K. D.; Megonigal, P.; Morris, J. T.; Schile, L. M.; Simard, M.; Sutton-Grier, A.; Takekawa, J.; Troxler, T.; Weller, D.; Woo, I.

2015-12-01

Despite their high rates of long-term carbon (C) sequestration when compared to upland ecosystems, coastal C accounting is only recently receiving the attention of policy makers and carbon markets. Assessing accuracy and uncertainty in net C flux estimates requires both direct and derived measurements based on both short and long term dynamics in key drivers, particularly soil accretion rates and soil organic content. We are testing the ability of remote sensing products and national scale datasets to estimate biomass and soil stocks and fluxes over a wide range of spatial and temporal scales. For example, the 2013 Wetlands Supplement to the 2006 IPCC GHG national inventory reporting guidelines requests information on development of Tier I-III reporting, which express increasing levels of detail. We report progress toward development of a Carbon Monitoring System for "blue carbon" that may be useful for IPCC reporting guidelines at Tier II levels. Our project uses a current dataset of publically available and contributed field-based measurements to validate models of changing soil C stocks, across a broad range of U.S. tidal wetland types and landuse conversions. Additionally, development of biomass algorithms for both radar and spectral datasets will be tested and used to determine the "price of precision" of different satellite products. We discuss progress in calculating Tier II estimates focusing on variation introduced by the different input datasets. These include the USFWS National Wetlands Inventory, NOAA Coastal Change Analysis Program, and combinations to calculate tidal wetland area. We also assess the use of different attributes and depths from the USDA-SSURGO database to map soil C density. Finally, we examine the relative benefit of radar, spectral and hybrid approaches to biomass mapping in tidal marshes and mangroves. While the US currently plans to report GHG emissions at a Tier I level, we argue that a Tier II analysis is possible due to national

Barrier-island and estuarine-wetland physical-change assessment after Hurricane Sandy

Science.gov (United States)

Plant, Nathaniel G.; Smith, Kathryn E.L.; Passeri, Davina L.; Smith, Christopher G.; Bernier, Julie C.

2018-04-03

IntroductionThe Nation’s eastern coast is fringed by beaches, dunes, barrier islands, wetlands, and bluffs. These natural coastal barriers provide critical benefits and services, and can mitigate the impact of storms, erosion, and sea-level rise on our coastal communities. Waves and storm surge resulting from Hurricane Sandy, which made landfall along the New Jersey coast on October 29, 2012, impacted the U.S. coastline from North Carolina to Massachusetts, including Assateague Island, Maryland and Virginia, and the Delmarva coastal system. The storm impacts included changes in topography, coastal morphology, geology, hydrology, environmental quality, and ecosystems.In the immediate aftermath of the storm, light detection and ranging (lidar) surveys from North Carolina to New York documented storm impacts to coastal barriers, providing a baseline to assess vulnerability of the reconfigured coast. The focus of much of the existing coastal change assessment is along the ocean-facing coastline; however, much of the coastline affected by Hurricane Sandy includes the estuarine-facing coastlines of barrier-island systems. Specifically, the wetland and back-barrier shorelines experienced substantial change as a result of wave action and storm surge that occurred during Hurricane Sandy (see also USGS photograph, http://coastal.er.usgs.gov/hurricanes/sandy/photo-comparisons/virginia.php). Assessing physical shoreline and wetland change (land loss as well as land gains) can help to determine the resiliency of wetland systems that protect adjacent habitat, shorelines, and communities.To address storm impacts to wetlands, a vulnerability assessment should describe both long-term (for example, several decades) and short-term (for example, Sandy’s landfall) extent and character of the interior wetlands and the back-barrier-shoreline changes. The objective of this report is to describe several new wetland vulnerability assessments based on the detailed physical changes

Monitoring the chemical nature of the carbon pool of Louisiana wetland soils undergoing erosion: carbon speciation and redox processes

Science.gov (United States)

Haywood, B.; Cook, R. L.; Hayes, M. P.; White, J. R.

2017-12-01

Wetlands account for approximately one third of all the soil carbon on the planet; however, due to erosion caused by a range of factors, including sea level rising, they are also some of the most vulnerable carbon pools. Small changes within this sequestered carbon pool can have a large impact on atmospheric CO2 levels. Thus, it is essential to understand how this sequestered carbon reacts to wetland loss in order to gain deeper insight into the global carbon cycle. In the study to be presented, Barataria Bay, Louisiana, USA is used as a model system for wetland loss. A sampling site and sampling grid has been established, and consists of three transects on and from an individual island. Each transect has five different distances ranging from 2 m inland to 8 m outland (into the water). At each of these different distances, depth profiles from 0 to 100 cm for inland samples, and 0-70 cm for submerged samples, were collected in order to identify spatial trends not only from inland to submerged, but also through the depth of the soil profile. Three types of samples were collected, namely water, pore water, and soil samples, with the latter being obtained from the combined collection of water and core samples. Samples have undergone spectroscopic characterizing including UV/Vis, fluorescence (excitation emission matrices, EEMs, and parallel factor, PARAFAC, analysis of the EEMs), nuclear magnetic resonance (NMR, solid state 13C), and electron pair resonance (EPR) spectroscopy in concert with inductively coupled plasma atomic emission spectroscopy to monitor the initial state of carbon speciation as well as redox processes. The data are used to establish a starting point on which to monitor changes within the carbon pool as the sampling site experience erosion over the next few years. The discussion will focus on the lability of different carbon pools and the potential lability-inducing mechanisms as well as the initial carbon speciation and redox state of the sampling

Nutrient and salt relations of Pterocarpus officinalis L. in coastal wetlands of the Caribbean: assessment through leaf and soil analyses.

Science.gov (United States)

Ernesto Medina; Elvira Cuevas; Ariel Lugo

2007-01-01

Pterocarpus officinalis L. is a dominant tree of freshwater coastal wetlands in the Caribbean and the Guiana regions. It is frequently associated with mangroves in areas with high rainfall and/or surface run-off. We hypothesized that P. officinalis is a freshwater swamp species that when occurring in association with mangroves occupies low-salinity soil microsites, or...

From frequent hurricanes to the Deepwater Horizon oil spill in coastal Louisiana: the impact of regulatory change

Directory of Open Access Journals (Sweden)

So-Min Cheong

2014-06-01

Full Text Available The issue of whether adaptations to past disasters can impede adaptation to new disasters of a different type or intensity will be analyzed by examining the transition from frequent hurricanes to the Deepwater Horizon oil spill in coastal Louisiana. In particular, the effects of changed regulatory structures from the Stafford Act to the Oil Pollution Act of 1990 in response to the Deepwater Horizon oil spill are investigated. The article describes how the federal, state, and local governments adjust. In addition, it illustrates the shifting focus on the environment with the activation of the Oil Pollution Act and the Clean Water Act. It wraps up with a discussion of the uncertainty that is pervasive in the case of the oil spill derived from changed regulations and the novelty of the disaster.

Complex community of nitrite-dependent anaerobic methane oxidation bacteria in coastal sediments of the Mai Po wetland by PCR amplification of both 16S rRNA and pmoA genes.

Science.gov (United States)

Chen, Jing; Zhou, Zhichao; Gu, Ji-Dong

2015-02-01

In the present work, both 16S rRNA and pmoA gene-based PCR primers were employed successfully to study the diversity and distribution of n-damo bacteria in the surface and lower layer sediments at the coastal Mai Po wetland. The occurrence of n-damo bacteria in both the surface and subsurface sediments with high diversity was confirmed in this study. Unlike the two other known n-damo communities from coastal areas, the pmoA gene-amplified sequences in the present work clustered not only with some freshwater subclusters but also within three newly erected marine subclusters mostly, indicating the unique niche specificity of n-damo bacteria in this wetland. Results suggested vegetation affected the distribution and community structures of n-damo bacteria in the sediments and n-damo could coexist with sulfate-reducing methanotrophs in the coastal ecosystem. Community structures of the Mai Po n-damo bacteria based on 16S rRNA gene were different from those of either the freshwater or the marine. In contrast, structures of the Mai Po n-damo communities based on pmoA gene grouped with the marine ones and were clearly distinguished from the freshwater ones. The abundance of n-damo bacteria at this wetland was quantified using 16S rRNA gene PCR primers to be 2.65-6.71 × 10(5) copies/g dry sediment. Ammonium and nitrite strongly affected the community structures and distribution of n-damo bacteria in the coastal Mai Po wetland sediments.

Transgressive Shoreface Response in the Mississippi River DeltaShoreface Sediment Budget Influence on Barrier Island Evolution, Louisiana, USA

Science.gov (United States)

Beasley, B.; Georgiou, I. Y.; Miner, M. D.

2017-12-01

In Louisiana barrier islands are undergoing rapid morphological change due to shoreface retreat and increasing bay tidal prism driven by high rates of relative sea-level rise (RSLR) (1 cm/yr) and interior wetland loss, respectively. Previous works utilized historical region-scale bathymetry change and shoreline change analyses to assess large-scale coastal evolution. However, more localized assessments considering the role of sediment transport processes in regional evolution are lacking. This is essential to predicting coastal change trajectories and allocating limited sand resources for nourishment. Using historic bathymetric and shoreline data dating to the 1890s for the Louisiana coast, 100-m spaced shore-normal transects were created to track meter-scale elevation change for 1890, 1930, 1980, 2006, and 2015. An automated framework was used to quantify and track barrier island evolution parameters such as shoreline change, area, width, bathymetric contour migration, and shoreface slope. During the 125 yr analysis period, shoreline erosion mean rates slowed from 12 to 6 m/yr while lower shoreface migration mean rates increased from 5 to 25 m/yr. Locally, retreat rates for the Caminada Headland upper shoreface slowed from 18 to 8 m/yr while lower shoreface retreat rates increased from 8 to 14m/yr. The Timbalier Islands experienced increased migration rates along the entire shoreface, while the lower shoreface of the Isles Dernieres transitioned from progradational to erosional (-5 m/yr in 1890 to 20 m/yr in 2006). Our analysis suggests that although shoreline erosion rates decreased, overall landward migration of the barrier system increased as the shoreface steepened. Our results illustrate that monitoring subaerial island erosion rates are insufficient for evaluating regional dynamics of transgressive coastal systems. The longevity of barriers appears diminished due to a reduction in the shoreface sediment available and further corroborates the role of the

Question of uncertainty : Transitioning from hurricanes to the BP Deepwater Horizon oil spill in coastal Louisiana

Science.gov (United States)

Cheong, S.

2013-12-01

Uncertainty is highlighted in the case of the oil spill. Hurricane is considered a known factor that people are used to and know how to handle. This uncertainty is primarily attributed to the magnitude of the spill. As the largest spill in the U.S., the long-term effects of the spill are difficult to assess. Uncertainty, however, has more to do with the novelty of the disaster and the accompanying regulatory change than the specific characteristics of this spill such as the size and longevity of the spill. The unfamiliarity with the Oil Pollution Act results in a lack of knowledge and uncertainty about local and state responses to the spill. The unpreparedness and unfamiliarity of this spill accompanied by different regulations underlie people's sense of uncertainty. This paper examines coastal Louisiana's shift from frequent hurricanes to the BP Deepwater Horizon oil spill in 2010, particularly focusing on the effects of changed regulations from the Stafford Act to the Oil Pollution Act. It documents how the federal, state, and local governments adjust, and discusses the shifting emphasis to the environment with the activation of the Oil Pollution Act and the Clean Water Act. One assumption is that people's established ways of behavior are commonly shaped by their previous experience of disasters, but this can paradoxically hinder their timely adaptation to new or different, high- impact environmental change. This leads to testing the hypothesis whether greater vulnerabilities result from adaptations to previous and well-known disasters. Results: The structural differences in regulations dictate the way governments and communities respond and adapt to the oil spill. The new set of regulations during the BP Deepwater Horizon oil spill unlike the ones during hurricanes served as barriers to adaptation. Governments at federal, state, and local levels had difficulties adjusting to new rules and changed authorities, and they, in turn, generated uncertainty and

Late-Holocene Environmental Reconstruction and Depositional History from a Taxodium Swamp near Lake Pontchartrain in Southern Louisiana

Science.gov (United States)

Ryu, J.; Bianchette, T. A.; Liu, K. B.; Yao, Q.; Maiti, K.

2017-12-01

The hydrological and environmental history of estuarine wetlands in Louisiana is not well-documented. To better understand the depositional processes in coastal wetlands, this study aims to reconstruct the environmental changes and document the occurrence of event deposits found in a bald cypress (Taxodium distichum) swamp approximately 800 m west of Lake Pontchartrain, a site susceptible to wind-generated storm surges as well as inundation from other fluvial and lacustrine processes. 210Pb analysis of a 59 cm sediment core (WMA-1) suggests that it has a sedimentation rate of 0.39 cm/year, consistent with the detection of a 137Cs peak at 17 cm from the core top. Results of sedimentological, geochemical, and palynological analyses reveal that the core contains two distinct sediment facies: an organic-rich dark brown peat unit from 0 to 29 cm containing low concentrations of terrestrial elements (e.g., Ti, Fe, and K), and a clay unit from 30 to 59 cm with elevated concentrations of most elements. Two thin clay layers, at 3-5 cm and 14-19 cm, embedded in the upper peat section are probably attributed to two recent storm events, Hurricane Isaac (2012) and Hurricane Gustav (2008), because both hurricanes caused heavy rain and significant storm-surge flooding at the study site. The pollen assemblage in the clay section is dominated by TCT (mainly Taxodium), but it is replaced by Salix and wetland herbaceous taxa in the overlying peat section. The multi-proxy data suggest that a cypress swamp has been present at the site for at least several hundred years but Taxodium was being replaced by willow (Salix) and other bottomland hardwood trees and wetland herbs as the water level dropped. Human activities may have been an important factor causing the hydrological and ecological changes at the site during the past century.

A Regional Guidebook for Applying the Hydrogeomorphic Approach to Assessing Wetland Functions of Depression Wetlands in the Upper Des Plaines River Basin

Science.gov (United States)

2006-05-01

Wetlands and Coastal Ecology Branch; Dr. David J. Tazik, Chief, Eco- system Evaluation and Engineering Division; and Dr. Edwin A. Theriot, Direc- tor, EL...wetlands (Euliss and Mushet 1996, Azous and Horner 2001, Bhaduri et al. 1997) and nutrient loading into those wetlands. The overall LU score is...Euliss, N. H., and Mushet , D. M. (1996). “Water-level fluctuation in wetlands as a function of landscape condition in the prairie pothole region

Biological and geochemical data along Indian Point, Vermilion Bay, Louisiana

Science.gov (United States)

Richwine, Kathryn A.; Marot, Marci E.; Smith, Christopher G.; Osterman, Lisa E.; Adams, C. Scott

2015-09-14

Scientists from the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center collected shallow sediment cores and surface samples from a coastal salt marsh environment next to Vermilion Bay in southwest Louisiana in January 2013. The sampling was part of a larger USGS study to gather data for assessing environmental changes over the past 150 years. The objective of the study was to expand upon the historical context of sea level and storms affecting coastal systems and how these systems might change under persistent or varying conditions. The data from this report add to a regional environmental change database that aids with the continuing effort to understand the evolution of coastal systems.

Monitoring Ecological and Environmental Changes in Coastal Wetlands in the Yellow River Delta from 1987 to 2010 Using Remote Sensing Techniques

Science.gov (United States)

Shang, Kun; Zhao, Dong; Gan, Fuping; Xiao, Chenchao

2016-04-01

Many wetlands in the world have degraded rapidly in recent years, especially in China. The Yellow River Delta (YRD) is one of the largest deltas in China. The YRD Nature Reserve is one of China's most complete, broadest, and youngest wetland ecological systems in the warm-temperate zone. Most previous studies have placed particular emphasis on ecological environment or landscape of the YRD based on the distribution of wetlands. In recent years, with the rapid development of the city of Dongying, located in the YRD, the impacts of human activities are increasingly significant, so that monitoring changes in the wetlands has become especially important. In this research, we applied an improved Support Vector Machine (SVM) approach to wetland classification based on feature band set construction and optimization using seven Landsat images. By extracting waterlines, classifying wetlands and deriving landscape parameters, we have achieved high-frequency comprehensive monitoring of the wetlands in the YRD over a relatively long period. It offers a better estimate of wetland change trends than certain previous studies. From 1987 to 2010, the natural waterline primarily experienced erosion due to precipitation abnormalities, as well as coastal exploitation, as the co-analyzed meteorological data suggest. Meanwhile, the artificial waterline barely changed. The wetland area decreased rapidly from approximately 4,607 km2 to 2,714 km2 between 1987 and 2000. Ecological resilience and landscape diversity also decreased significantly during this period. The major impact factors were most likely urbanization, population expansion and the exploitation of the wetlands. After 2000, ecological resilience exhibited a positive trend. However, because newly built aquatic farms and salt works caused serious damages and threatened the natural beach landscape, the landscape fragmentation of muddy and sandy beaches increased after 2000. According to the results, more effective policies and

Wetland shoreline recession in the Mississippi River Delta from petroleum oiling and cyclonic storms

Science.gov (United States)

Rangoonwala, Amina; Jones, Cathleen E.; Ramsey, Elijah W.

2016-01-01

We evaluate the relative impact of petroleum spill and storm surge on near-shore wetland loss by quantifying the lateral movement of coastal shores in upper Barataria Bay, Louisiana (USA), between June 2009 and October 2012, a study period that extends from the year prior to the Deepwater Horizon spill to 2.5 years following the spill. We document a distinctly different pattern of shoreline loss in the 2 years following the spill, both from that observed in the year prior to the spill, during which there was no major cyclonic storm, and from change related to Hurricane Isaac, which made landfall in August 2012. Shoreline erosion following oiling was far more spatially extensive and included loss in areas protected from wave-induced erosion. We conclude that petroleum exposure can substantially increase shoreline recession particularly in areas protected from storm-induced degradation and disproportionally alters small oil-exposed barrier islands relative to natural erosion.

Eten's Coastal Wetland, its geomorphology, water quality and biodiversity

Science.gov (United States)

Rojas Carbajal, T. V.; Bartl, K.; Loayza Muro, R.; Abad, J. D.

2017-12-01

The Eten's wetland is located in the lower part of the Chancay-Lambayeque River basin at the Peruvian coast. This wetland contains salt and fresh marshes, swamps, lagoons and an estuary which is the result of Reque River's morphodynamics. It provides a great source of totora (Schoenoplectus californicus), a native plant that is used for knitting hats which are an ancient cultural expression in Lambayeque. UNESCO recognized this wetland as one of the ecosystems with the greatest biodiversity along the South Pacific Coast, providing a unique habitat for migratory birds, such as the Peruvian Tern (Sternula lorata). This bird has been classified as endangered in 2005, by the International Union for Conservation of Nature (IUCN). When the area of a wetland is reduced, the resting point function is affected leading to loss in biodiversity due to the habitat conditions are not the same. In 2005, Lambayeque's government established an area of 1377 Ha in order to preserve wetland's ecosystem and Eten's archeological value but wet areas were reduced to 200 Ha. This reduction was promoted by agriculture, urbanization and an inadequate urban waste disposal. The scope of the study is to assess the environmental impacts that affect Eten's wetland. Preliminary results of an assessment with remote sensing indicate that: 1) the Reque River's geomorphic activity was reduced by urbanization, thus, the connection between surface water bodies has been lost, leading the drying out of ponds, 2) the conversion of wet areas to agricultural land, and 3) the natural interaction between the Reque River and the Pacific Ocean was modified due to water control upstream, resulting in a dryer wetland during the last years. Furthermore, the aquatic biodiversity of the wetland was assessed through a biomonitoring method in order to study the impact of water contamination. Four benthic macroinvertebrate Families (Hydrophilidae, Baetidae, Planorbidae and Palaemonidae) were found. The quality of the

Monitoring Coastal Marshes for Persistent Flooding and Salinity Stress

Science.gov (United States)

Kalcic, Maria

2010-01-01

Our objective is to provide NASA remote sensing products that provide inundation and salinity information on an ecosystem level to support habitat switching models. Project born out of need by the Coastal Restoration Monitoring System (CRMS), joint effort by Louisiana Department of Natural Resources and the U.S. Geological Survey, for information on persistence of flooding by storm surge and other flood waters. The results of the this work support the habitat-switching modules in the Coastal Louisiana Ecosystem Assessment and Restoration (CLEAR) model, which provides scientific evaluation for restoration management. CLEAR is a collaborative effort between the Louisiana Board of Regents, the Louisiana Department of Natural Resources (LDNR), the U.S. Geological Survey (USGS), and the U.S. Army Corps of Engineers (USACE). Anticipated results will use: a) Resolution enhanced time series data combining spatial resolution of Landsat with temporal resolution of MODIS for inundation estimates. b) Potential salinity products from radar and multispectral modeling. c) Combined inundation and salinity inputs to habitat switching module to produce habitat switching maps (shown at left)

Restoration of freshwater Cypress-Tupelo Wetlands in the southeastern U.S. following severe hurricanes

Science.gov (United States)

Conner, William H.; Krauss, Ken W.; Shaffer, Gary P.

2012-01-01

Freshwater forested wetlands commonly occur in the lower Coastal Plain of the southeastern US with baldcypress (Taxodium distichum [L.] L.C. Rich.) and water tupelo (Nyssa aquatica L.) often being the dominant trees. Extensive anthropogenic activities combined with eustatic sea-level rise and land subsidence have caused widespread hydrological changes in many of these forests. In addition, hurricanes (a common, although aperiodic occurrence) cause wide-spread damage from wind and storm surge events, with impacts exacerbated by human-mediated coastal modifications (e.g., dredging, navigation channels, etc.). Restoration of forested wetlands in coastal areas is important because emergent canopies can greatly diminish wind penetration, thereby reducing the wind stress available to generate surface waves and storm surge that are the major cause of damage to coastal ecosystems and their surrounding communities. While there is an overall paucity of large-scale restoration efforts within coastal forested wetlands of the southeastern US, we have determined important characteristics that should drive future efforts. Restoration efforts may be enhanced considerably if coupled with hydrological enhancement, such as freshwater, sediment, or sewage wastewater diversions. Large-scale restoration of coastal forests should be attempted to create a landscape capable of minimizing storm impacts and maximizing wetland sustainability in the face of climate change. Planting is the preferred regeneration method in many forested wetland sites because hydrological alterations have increased flooding, and planted seedlings must be protected from herbivory to enhance establishment. Programs identifying salt tolerance in coastal forest tree species need to be continued to help increase resilience to repetitive storm surge events.

Interactions Between Wetlands and Tidal Inlets

National Research Council Canada - National Science Library

Sanchez, Alejandro

2008-01-01

This Coastal and Hydraulics Engineering Technical Note (CHETN) presents numerical simulations investigating how the loss of wetlands in estuaries modifies tidal processes in inlet navigation channels...

Fringe wetlands

International Nuclear Information System (INIS)

Lugo, A.E.

1990-01-01

Fringe wetlands are characterized by the dominance of few species, a clear species zonation, synchrony of ecological processes with episodic events, and simplicity in the structure of vegetation. The structure and ecosystem dynamics of fringe forested wetlands are presented with emphasis on saltwater wetlands because they have been studied more than freshwater ones. The study areas were Caribbean and Florida mangroves. Fringe wetlands are found on the water edge of oceans, inland estuaries, and lakes. Water motion in the fringe is bi-directional and perpendicular to the forest and due mostly to tidal energy in oceanic and estuarine fringes. in lakes, water moves in and out of the fringe under the influence of wind, waves, or seiches. some fringe forests are occasionally flushed by terrestrial runoff or aquifer discharge. In contrast, fringe forests located on small offshore islands or steep coastal shroes are isolated from terrestrial runoff or aquifer discharge, and their hydroperiod is controlled by tides and waves only. Literature reviews suggest that ecosystem parameters such as vegetation structure, tree growth, primary productivity, and organic matter in sediments respond proportionally to hydrologic energy. Human activity that impacts on fringe forested wetlands include harvesting of trees, oil pollution and eutrophication. 72 refs., 12 figs., 9 tabs

Subsidence Contours for South Louisiana; UTM 15N NAD83; LRA (2005); [subsidence_contours

Data.gov (United States)

Louisiana Geographic Information Center — The GIS data shapefile represents average subsidence contour intervals (0.02 cm/year over 10,000 years) for Coastal LA derived from the following: Kulp, M.A., 2000,...

Associations between the molecular and optical properties of dissolved organic matter in the Florida Everglades, a model coastal wetland system

Science.gov (United States)

Wagner, Sasha; Jaffe, Rudolf; Cawley, Kaelin; Dittmar, Thorsten; Stubbins, Aron

2015-11-01

Optical properties are easy-to-measure proxies for dissolved organic matter (DOM) composition, source and reactivity. However, the molecular signature of DOM associated with such optical parameters remains poorly defined. The Florida coastal Everglades is a subtropical wetland with diverse vegetation (e.g., sawgrass prairies, mangrove forests, seagrass meadows) and DOM sources (e.g., terrestrial, microbial and marine). As such, the Everglades is an excellent model system from which to draw samples of diverse origin and composition to allow classically-defined optical properties to be linked to molecular properties of the DOM pool. We characterized a suite of seasonally- and spatially-collected DOM samples using optical measurements (EEM-PARAFAC, SUVA254, S275-295, S350-400, SR, FI, freshness index and HIX) and ultrahigh resolution mass spectrometry (FTICR-MS). Spearman’s rank correlations between FTICR-MS signal intensities of individual molecular formulae and optical properties determined which molecular formulae were associated with each PARAFAC component and optical index. The molecular families that tracked with the optical indices were generally in agreement with conventional biogeochemical interpretations. Therefore, although they represent only a small portion of the bulk DOM pool, absorbance and fluorescence measurements appear to be appropriate proxies for the aquatic cycling of both optically-active and associated optically-inactive DOM in coastal wetlands.

Across Hydrological Interfaces from Coastal Watersheds to the Open Lake: Finding Landscape Signals in the Great Lakes Coastal Zone

Science.gov (United States)

Over the past decade, our group has been working to bring coastal ecosystems into integrated basin-lakewide monitoring and assessment strategies for the Great Lakes. We have conducted a wide range of research on coastal tributaries, coastal wetlands, semi-enclosed embayments an...

Modeled CO2 Emissions from Coastal Wetland Transitions to Other Land Uses: Tidal Marshes, Mangrove Forests, and Seagrass Beds

Directory of Open Access Journals (Sweden)

Catherine E. Lovelock

2017-05-01

Full Text Available The sediments of coastal wetlands contain large stores of carbon which are vulnerable to oxidation once disturbed, resulting in high levels of CO2 emissions that may be avoided if coastal ecosystems are conserved or restored. We used a simple model to estimate CO2 emissions from mangrove forests, seagrass beds, and tidal marshes based on known decomposition rates for organic matter in these ecosystems under either oxic or anoxic conditions combined with assumptions of the proportion of sediment carbon being deposited in either oxic or anoxic environments following a disturbance of the habitat. Our model found that over 40 years after disturbance the cumulative CO2 emitted from tidal marshes, mangrove forests, and seagrass beds were ~70–80% of the initial carbon stocks in the top meter of the sediment. Comparison of our estimates of CO2 emissions with empirical studies suggests that (1 assuming 50% of organic material moves to an oxic environment after disturbance gives rise to estimates that are similar to CO2 emissions reported for tidal marshes; (2 field measurements of CO2 emissions in disturbed mangrove forests were generally higher than our modeled emissions that assumed 50% of organic matter was deposited in oxic conditions, suggesting higher proportions of organic matter may be exposed to oxic conditions after disturbance in mangrove ecosystems; and (3 the generally low observed rates of CO2 emissions from disturbed seagrasses compared to our estimates, assuming removal of 50% of the organic matter to oxic environments, suggests that lower proportions may be exposed to oxic conditions in seagrass ecosystems. There are significant gaps in our knowledge of the fate of wetland sediment carbon in the marine environment after disturbance. Greater knowledge of the distribution, form, decomposition, and emission rates of wetland sediment carbon after disturbance would help to improve models.

Assessing biomass of diverse coastal marsh ecosystems using statistical and machine learning models

Science.gov (United States)

Mo, Yu; Kearney, Michael S.; Riter, J. C. Alexis; Zhao, Feng; Tilley, David R.

2018-06-01

The importance and vulnerability of coastal marshes necessitate effective ways to closely monitor them. Optical remote sensing is a powerful tool for this task, yet its application to diverse coastal marsh ecosystems consisting of different marsh types is limited. This study samples spectral and biophysical data from freshwater, intermediate, brackish, and saline marshes in Louisiana, and develops statistical and machine learning models to assess the marshes' biomass with combined ground, airborne, and spaceborne remote sensing data. It is found that linear models derived from NDVI and EVI are most favorable for assessing Leaf Area Index (LAI) using multispectral data (R2 = 0.7 and 0.67, respectively), and the random forest models are most useful in retrieving LAI and Aboveground Green Biomass (AGB) using hyperspectral data (R2 = 0.91 and 0.84, respectively). It is also found that marsh type and plant species significantly impact the linear model development (P biomass of Louisiana's coastal marshes using various optical remote sensing techniques, and highlights the impacts of the marshes' species composition on the model development and the sensors' spatial resolution on biomass mapping, thereby providing useful tools for monitoring the biomass of coastal marshes in Louisiana and diverse coastal marsh ecosystems elsewhere.

Land area change analysis following hurricane impacts in Delacroix, Louisiana, 2004--2009

Science.gov (United States)

Palaseanu-Lovejoy, Monica; Kranenburg, Christine J.; Brock, John C.

2012-01-01

The purpose of this project is to provide improved estimates of Louisiana wetland land loss due to hurricane impacts between 2004 and 2009 based upon a change detection mapping analysis that incorporates pre- and post-landfall (Hurricanes Katrina, Rita, Gustav, and Ike) fractional water classification of a combination of high resolution (QuickBird, IKONOS and Geoeye-1) and medium resolution (Landsat) satellite imagery. This second dataset focuses on Hurricanes Katrina and Gustav, which made landfall on August 29, 2005, and September 1, 2008, respectively. The study area is an approximately 1208-square-kilometer region surrounding Delacroix, Louisiana, in the eastern Delta Plain. Overall, 77 percent of the area remained unchanged between 2004 and 2009, and over 11 percent of the area was changed permanently by Hurricane Katrina (including both land gain and loss). Less than 3 percent was affected, either temporarily or permanently, by Hurricane Gustav. A related dataset (SIM 3141) focused on Hurricane Rita, which made landfall on the Louisiana/Texas border on September 24, 2005, as a Category 3 hurricane.

Analysis and Synthesis of WAVCIS Data for Characteristics of Waves and Currents on Louisiana Coast

Science.gov (United States)

Li, C.; Gibson, B.; Huang, W.; Luo, Y.; Milan, B.

2017-12-01

Texas-Louisiana coastal currents have been studied before, with a generally well-known pattern that is quasi steady except during the summer when it may weaken or reverse briefly. In the past decade, lot more efforts have been made and there is a large quantity of current velocity data accumulated. Among these data are those from the long-term mooring observations from the Wave Current-Surge Information System (WAVCIS), with a focus on the Louisiana coastal waters. More specifically, velocity and wave time series from current meters and pressure sensors or directional wave sensors at several locations on Louisiana coast provided unique opportunity to analyze and synthesize the characteristics of waves and currents on both east and west side of the Birdfoot Delta. In this study, we assembled all available WAVCIS data for a thorough analysis and synthesis of the characteristics of waves and coastal current in the area as a function of weather during different seasons. Year-to-year variabilities and seasonal variations are discussed. Spectrum, harmonic, and EOF analyses allowed a description and comparison of circulation patterns, wave and flow energy regimes, vertical shear of horizontal flows, tidal characteristics, synoptic weather effect, and severe weather impact. We provide basic statistics, as well as classifications of type of flows/circulations, and the major mechanisms that contribute to the variability.

Understanding Coastal Wetland Vulnerability to Sea-Level Rise Enhanced Inundation Using Real-Time Stage Monitoring, LiDAR, and Monte Carlo Simulation in Everglades National Park

Science.gov (United States)

Cooper, H.; Zhang, C.

2017-12-01

Coastal wetlands are one of the most productive ecological systems in the world, providing critical habitat area and valuable ecosystem services such as carbon sequestration. However, due to their location in low lying areas, coastal wetlands are particularly vulnerable to sea-level rise (SLR). Everglades National Park (ENP) encompasses the southern-most portion of the Greater Everglades Ecosystem, and is the largest subtropical wetland in the USA. Water depths have shown to have a significant relationship to vegetation community composition and organization while also playing a crucial role in vegetation health throughout the Everglades. Live plants play a vital role in maintaining soil structure (i.e. elevation), and decreases in vegetation health can cause peat collapse or wetland loss resulting in dramatic habitat, organic soil, and elevation loss posing concerns for Everglades management and restoration. One suspected mechanism for peat collapse is enhanced inundation due to SLR, thus mapping and modeling water depths is a critical component to understanding the potential impacts of future SLR. Previous research in the Everglades focused on a conventional Water Depth Model (WDM) approach where a Digital Elevation Model (DEM) is subtracted from a Water Table Elevation Model (WTEM). In this study, the conventional WDM approach is extended to a more rigorous WDM technique so that the accuracy and precision of the underlying data may be considered. Monte Carlo simulation is used to propagate probability distributions through our SLR depth model using our Random Forest-based LiDAR DEM, Empirical Bayesian Kriging-based WTEMs, uncertainties in vertical datums, soil accretion projections, and regional sea-level rise projections. Water depth maps were produced for the wet and dry seasons in April and October, which successfully revealed the potential spatial and temporal water depth variations due to future SLR. It is concluded that a more rigorous WDM technique helps

Forested Wetlands: Functions, Benefits and the Use of Best Management Practices

Science.gov (United States)

David J. Welsch; David L. Smart; James N. Boyer; Paul Minken; Howard C. Smith; Tamara L. McCandless

1995-01-01

Wetlands are complex and fascinating ecosystems that perform a variety of functions of vital importance to the environment and to the society whose very existence depends on the quality of the environment. Wetlands regulate water flow by detaining storm flows for short periods thus reducing Wetlands protect lake shore and coastal areas by buffering the erosive action...

Land Use in Korean Tidal Wetlands: Impacts and Management Strategies

Science.gov (United States)

Hong, Sun-Kee; Koh, Chul-Hwan; Harris, Richard R.; Kim, Jae-Eun; Lee, Jeom-Sook; Ihm, Byung-Sun

2010-05-01

The coastal landscapes in southwestern Korea include a diverse array of tidal wetlands and salt marshes. These coastal zones link the ecological functions of marine tidal wetlands and freshwater ecosystems with terrestrial ecosystems. They are rich in biological diversity and play important roles in sustaining ecological health and processing environmental pollutants. Korean tidal wetlands are particularly important as nurseries for economically important fishes and habitats for migratory birds. Diking, draining, tourism, and conversion to agricultural and urban uses have adversely affected Korean tidal wetlands. Recent large development projects have contributed to further losses. Environmental impact assessments conducted for projects affecting tidal wetlands and their surrounding landscapes should be customized for application to these special settings. Adequate environmental impact assessments will include classification of hydrogeomorphic units and consideration of their responses to biological and environmental stressors. As is true worldwide, Korean laws and regulations are changing to be more favorable to the conservation and protection of tidal wetlands. More public education needs to be done at the local level to build support for tidal wetland conservation. Some key public education points include the role of tidal wetlands in maintaining healthy fish populations and reducing impacts of nonpoint source pollution. There is also a need to develop procedures for integrating economic and environmental objectives within the overall context of sustainable management and land uses.

Dissolved Organic Matter (DOM) Export from Watersheds to Coastal Oceans

Science.gov (United States)

Chen, R. F.; Gardner, G. B.; Peri, F.

2016-02-01

Dissolved organic matter (DOM) from terrestrial plants and soils is transported by surface waters and groundwaters to coastal ocean waters. Along the way, photochemical and biological degradation can remove DOM, and in situ processes such as phytoplankton leaching and sediment sources can add to the DOM in the river water. Wetlands, especially coastal wetlands can add significant amounts of DOM that is carried by rivers and is exported through estuaries to coastal systems. We will present observational data from a variety of coastal systems (San Francisco Bay, Boston Harbor, Chesapeake Bay, Hudson River, the Mississippi River, and a small salt marsh in the Gulf of Mexico). High resolution measurements of chromophoric dissolved organic matter (CDOM) can be correlated with dissolved organic carbon (DOC) so can be used to estimate DOC in specific systems and seasons. Gradients in CDOM/DOC combined with water fluxes can be used to estimate DOC fluxes from a variety of coastal watersheds to coastal systems. Influences of land use, system size, residence time, DOM quality, and photochemical and biological degradation will be discussed. The significance of coastal wetlands in the land-to-ocean export of DOC will be emphasized.

Climate change: Potential impacts and interactions in wetlands of the United States

Science.gov (United States)

Burkett, Virginia; Kusler, Jon

2000-01-01

Wetlands exist in a transition zone between aquatic and terrestrial environments which can be altered by subtle changes in hydrology. Twentieth century climate records show that the United States is generally experiencing a trend towards a wetter, warmer climate; some climate models suggest that his trend will continue and possibly intensify over the next 100 years. Wetlands that are most likely to be affected by these and other potential changes (e.g., sea-level rise) associated with atmospheric carbon enrichment include permafrost wetlands, coastal and estuarine wetlands, peatlands, alpine wetlands, and prairie pothote wetlands. Potential impacts range from changes in community structure to changes in ecological function, and from extirpation to enhancement. Wetlands (particularly boreal peatlands) play an important role in the global carbon cycle, generally sequestering carbon in the form of biomass, methane, dissolved organic material and organic sediment. Wetlands that are drained or partially dried can become a net source of methane and carbon dioxide to the atmosphere, serving as a positive biotic feedback to global warming. Policy options for minimizing the adverse impacts of climate change on wetland ecosystems include the reduction of current anthropogenic stresses, allowing for inland migration of coastal wetlands as sea-level rises, active management to preserve wetland hydrology, and a wide range of other management and restoration options.

Exploring drivers of wetland hydrologic fluxes across parameters and space

Science.gov (United States)

Jones, C. N.; Cheng, F. Y.; Mclaughlin, D. L.; Basu, N. B.; Lang, M.; Alexander, L. C.

2017-12-01

Depressional wetlands provide diverse ecosystem services, ranging from critical habitat to the regulation of landscape hydrology. The latter is of particular interest, because while hydrologic connectivity between depressional wetlands and downstream waters has been a focus of both scientific research and policy, it remains difficult to quantify the mode, magnitude, and timing of this connectivity at varying spatial and temporary scales. To do so requires robust empirical and modeling tools that accurately represent surface and subsurface flowpaths between depressional wetlands and other landscape elements. Here, we utilize a parsimonious wetland hydrology model to explore drivers of wetland water fluxes in different archetypal wetland-rich landscapes. We validated the model using instrumented sites from regions that span North America: Prairie Pothole Region (south-central Canada), Delmarva Peninsula (Mid-Atlantic Coastal Plain), and Big Cypress Swamp (southern Florida). Then, using several national scale datasets (e.g., National Wetlands Inventory, USFWS; National Hydrography Dataset, USGS; Soil Survey Geographic Database, NRCS), we conducted a global sensitivity analysis to elucidate dominant drivers of simulated fluxes. Finally, we simulated and compared wetland hydrology in five contrasting landscapes dominated by depressional wetlands: prairie potholes, Carolina and Delmarva bays, pocosins, western vernal pools, and Texas coastal prairie wetlands. Results highlight specific drivers that vary across these regions. Largely, hydroclimatic variables (e.g., PET/P ratios) controlled the timing and magnitude of wetland connectivity, whereas both wetland morphology (e.g., storage capacity and watershed size) and soil characteristics (e.g., ksat and confining layer depth) controlled the duration and mode (surface vs. subsurface) of wetland connectivity. Improved understanding of the drivers of wetland hydrologic connectivity supports enhanced, region

Restored Drill Cuttings for Wetlands Creation: Results of Mesocosm Approach to Emulate Field Conditions Under Varying Salinity and Hydrologic Conditions

Energy Technology Data Exchange (ETDEWEB)

Hester, Mark W.; Shaffer, Gary P.; Willis Jonathan M.; DesRoches, Dennis J.

2001-02-21

This study builds upon earlier research conducted by Southeastern Louisiana University concerning the efficacy of utilizing processed drill cuttings as an alternative substrate source for wetland rehabilitation (wetland creation and restoration). Previous research has indicated that processed drill cuttings exhibit a low degree of contaminant migration from the process drill cuttings to interstitial water and low toxicity, as tested by seven-day mysid shrimp chronic toxicity trials.

Pre-Construction Biogeochemical Analysis of Mercury in Wetlands Bordering the Hamilton Army Airfield (HAAF) Wetlands Restoration Site. Part 2

National Research Council Canada - National Science Library

Best, Elly P; Fredrickson, Herbert L; Hintelmann, Holger; Clarisse, Olivier; Dimock, Brian; Lutz, Charles H; Lotufo, Gui R; Millward, Rod N; Bednar, Anthony J; Furey, John S

2007-01-01

...) is working with the San Francisco Basin Regional Water Board, California State Coastal Conservancy, and San Francisco Bay Conservation and Development Commission to reconstruct wetlands at the former...

Hurricane storm surge and amphibian communities in coastal wetlands of northwestern Florida

Science.gov (United States)

Gunzburger, M.S.; Hughes, W.B.; Barichivich, W.J.; Staiger, J.S.

2010-01-01

Isolated wetlands in the Southeastern United States are dynamic habitats subject to fluctuating environmental conditions. Wetlands located near marine environments are subject to alterations in water chemistry due to storm surge during hurricanes. The objective of our study was to evaluate the effect of storm surge overwash on wetland amphibian communities. Thirty-two wetlands in northwestern Florida were sampled over a 45-month period to assess amphibian species richness and water chemistry. During this study, seven wetlands were overwashed by storm surge from Hurricane Dennis which made landfall 10 July 2005 in the Florida panhandle. This event allowed us to evaluate the effect of storm surge overwash on water chemistry and amphibian communities of the wetlands. Specific conductance across all wetlands was low pre-storm (marine habitats are resistant to the effects of storm surge overwash. ?? 2010 Springer Science+Business Media B.V.

Coastal Massachusetts Submerged Aquatic Beds 1994-1996 Geodatabase

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Coastal Change Analysis Program (C-CAP) at NOAA Office for Coastal Management partnered with The Massachusetts Department of Environmental Protection Wetlands...

Coastal Massachusetts Submerged Aquatic Beds 1994-1996 Biotic

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Coastal Change Analysis Program (C-CAP) at NOAA Office for Coastal Management partnered with The Massachusetts Department of Environmental Protection Wetlands...

Coastal Massachusetts Submerged Aquatic Beds 1994-1996 Substrate

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Coastal Change Analysis Program (C-CAP) at NOAA Office for Coastal Management partnered with The Massachusetts Department of Environmental Protection Wetlands...

Coastal Massachusetts Submerged Aquatic Beds 1994-1996 Geoform

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Coastal Change Analysis Program (C-CAP) at NOAA Office for Coastal Management partnered with The Massachusetts Department of Environmental Protection Wetlands...

Associations between the molecular and optical properties of dissolved organic matter in the Florida Everglades, a model coastal wetland system

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Sasha eWagner

2015-11-01

Full Text Available Optical properties are easy-to-measure proxies for dissolved organic matter (DOM composition, source and reactivity. However, the molecular signature of DOM associated with such optical parameters remains poorly defined. The Florida coastal Everglades is a subtropical wetland with diverse vegetation (e.g., sawgrass prairies, mangrove forests, seagrass meadows and DOM sources (e.g., terrestrial, microbial and marine. As such, the Everglades is an excellent model system from which to draw samples of diverse origin and composition to allow classically-defined optical properties to be linked to molecular properties of the DOM pool. We characterized a suite of seasonally- and spatially-collected DOM samples using optical measurements (EEM-PARAFAC, SUVA254, S275-295, S350-400, SR, FI, freshness index and HIX and ultrahigh resolution mass spectrometry (FTICR-MS. Spearman’s rank correlations between FTICR-MS signal intensities of individual molecular formulae and optical properties determined which molecular formulae were associated with each PARAFAC component and optical index. The molecular families that tracked with the optical indices were generally in agreement with conventional biogeochemical interpretations. Therefore, although they represent only a small portion of the bulk DOM pool, absorbance and fluorescence measurements appear to be appropriate proxies for the aquatic cycling of both optically-active and associated optically-inactive DOM in coastal wetlands.

Comparison of the quantitative determination of soil organic carbon in coastal wetlands containing reduced forms of Fe and S

Science.gov (United States)

Passos, Tassia R. G.; Artur, Adriana G.; Nóbrega, Gabriel N.; Otero, Xosé L.; Ferreira, Tiago O.

2016-06-01

The performance of the Walkley-Black wet oxidation chemical method for soil organic carbon (SOC) determination in coastal wetland soils (mangroves, coastal lagoons, and hypersaline tidal flats) was evaluated in the state of Ceará along the semiarid coast of Brazil, assessing pyrite oxidation and its effects on soil C stock (SCS) quantification. SOC determined by the chemical oxidation method (CWB) was compared to that assessed by means of a standard elemental analyzer (CEA) for surficial samples (mangroves, whereas lower values were found in the other settings. CWB values were higher than CEA values. Significant differences in SCS calculations based on CWB and CEA were recorded for the coastal lagoons and hypersaline tidal flats. Nevertheless, the CWB and CEA values were strongly correlated, indicating that the wet oxidation chemical method can be used in such settings. In contrast, the absence of correlation for the mangroves provides evidence of the inadequacy of this method for these soils. Air drying and oxidation decrease the pyrite content, with larger effects rooted in oxidation. Thus, the wet oxidation chemical method is not recommended for mangrove soils, but seems appropriate for SOC/SCS quantification in hypersaline tidal flat and coastal lagoon soils characterized by lower pyrite contents.

Climate Change, Coastal Vulnerability and the Need for Adaptation Alternatives: Planning and Design Examples from Egypt and the USA

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S Jeffress Williams

2015-07-01

Full Text Available Planning and design of coastal protection for high-risk events with low to moderate or uncertain probabilities are a challenging balance of short- and long-term cost vs. protection of lives and infrastructure. The pervasive, complex, and accelerating impacts of climate change on coastal areas, including sea-level rise, storm surge and tidal flooding, require full integration of the latest science into strategic plans and engineering designs. While the impacts of changes occurring are global, local effects are highly variable and often greatly exacerbated by geophysical (land subsidence, faulting, oceanographic (ocean circulation, wind patterns and anthropogenic factors. Reducing carbon emissions is needed to mitigate global warming, but adaptation can accommodate at least near future change impacts. Adaptation should include alternatives that best match region-specific risk, time frame, environmental conditions, and the desired protection. Optimal alternatives are ones that provide protection, accommodate or mimic natural coastal processes, and include landforms such as barrier islands and wetlands. Plans are often for 50 years, but longer-term planning is recommended since risk from climate change will persist for centuries. This paper presents an assessment of impacts of accelerating climate change on the adequacy of coastal protection strategies and explores design measures needed for an optimum degree of protection and risk reduction. Three coastal areas facing similar challenges are discussed: Abu-Qir Bay, Nile River delta plain, Egypt; Lake Borgne, New Orleans, Louisiana delta plain; and the New York City region.

Innovative techniques cut costs in wetlands drilling

International Nuclear Information System (INIS)

Navarro, A.R.

1991-01-01

This paper reports on an approach to drilling oil and gas wells in sensitive wetlands areas contributed to a savings of over $1.2 million on a three-well, $3 million drilling project in south Louisiana. ARCO Oil and Gas Co. drilled a three-well project in the Bayou Sale field with a truck-mounted workover rig and a modified solids-control system. This smaller equipment eliminated the need to build a large location in the marsh. Traditional drilling techniques require a large drillsite to accommodate all the equipment of a modern drilling complex. However, recently imposed environmental regulations substantially limit, and in some cases prohibit, the use of these conventional techniques for drilling wells in wetlands areas. Based on the potentially huge economic and operational impact on the drilling industry because of these stricter regulations, alternatives to these traditional practices are essential

Assessing the cumulative impacts of geographically isolated wetlands on watershed hydrology using the SWAT model coupled with improved wetland modules.

Science.gov (United States)

Lee, S; Yeo, I-Y; Lang, M W; Sadeghi, A M; McCarty, G W; Moglen, G E; Evenson, G R

2018-06-07

Despite recognizing the importance of wetlands in the Coastal Plain of the Chesapeake Bay Watershed (CBW) in terms of ecosystem services, our understanding of wetland functions has mostly been limited to individual wetlands and overall catchment-scale wetland functions have rarely been investigated. This study is aimed at assessing the cumulative impacts of wetlands on watershed hydrology for an agricultural watershed within the Coastal Plain of the CBW using the Soil and Water Assessment Tool (SWAT). We employed two improved wetland modules for enhanced representation of physical processes and spatial distribution of riparian wetlands (RWs) and geographically isolated wetlands (GIWs). This study focused on GIWs as their hydrological impacts on watershed hydrology are poorly understood and GIWs are poorly protected. Multiple wetland scenarios were prepared by removing all or portions of the baseline GIW condition indicated by the U.S. Fish and Wildlife Service National Wetlands Inventory geospatial dataset. We further compared the impacts of GIWs and RWs on downstream flow (i.e., streamflow at the watershed outlet). Our simulation results showed that GIWs strongly influenced downstream flow by altering water transport mechanisms in upstream areas. Loss of all GIWs reduced both water routed to GIWs and water infiltrated into the soil through the bottom of GIWs, leading to an increase in surface runoff of 9% and a decrease in groundwater flow of 7% in upstream areas. These changes resulted in increased variability of downstream flow in response to extreme flow conditions. GIW loss also induced an increase in month to month variability of downstream flow and a decrease in the baseflow contribution to streamflow. Loss of all GIWs was shown to cause a greater fluctuation of downstream flow than loss of all RWs for this study site, due to a greater total water storage capacity of GIWs. Our findings indicate that GIWs play a significant role in controlling hydrological

IMPACTS OF WETLAND DEGRADATION IN NIGER DELTA NIGERIA AND ITS SIGNIFICANCE IN FLOOD CONTROL

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Enwere Chidimma Loveline

2015-08-01

Full Text Available  Wetlands perform a wide variety of functions that include flood control, ground water recharge, shore line stabilization, storm protection and climate moderation. However, despite these huge wetland functions, it has witnessed poor appreciation and dreadful conditions. Niger Delta has witnessed constant coastal erosion and rising sea level, this has led to large portions of the landmass being eroded. This paper aims to review some environmental effects of flooding in the Niger Delta region of Nigeria to provide the desired knowledge of role that wetlands play in reducing flood impacts. However, having witnessed the flood, the experience opened my eyes to the environmental challenges facing Niger Delta with respect to Wetlands degradation, poor perception of wetland values and functions, poor environmental practices and non-implementation of environmental regulations. This memorable experience rekindled the desire and motivation to seek a solution to wetland degradation with the aim of recognizing significance of wetlands at the centre of achieving both livelihood and biodiversity improvements to address coastal flooding problem.The study therefore concludes that wetlands are very significant in flood control and thus the conservation and restoration of wetlands, should put in place measures to reduce wetland destruction.International Journal of EnvironmentVolume-4, Issue-3, June-August 2015Page: 177-184

Dramatic decline of the bearded reedling, Panurus biarmicus, in Spanish Mediterranean wetlands

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Belenguer Barrionuevo, R.

2016-02-01

Full Text Available The apparent stability of the bearded reedling in Spanish inland wetlands contrasts with its threatened status in Spanish coastal wetlands. The species has already disappeared from some coastal areas in Catalonia and its situation is critical in the region of Valencia. In 2013 we studied the breeding populations in three wetlands in Valencia using two methods: census by exhaustive search of individuals (territory mapping and distance sampling using line transects. We estimated the trend of these populations from data obtained in previous censuses (2005 and 2006, and assessed their viability in the medium and short term using count–based population viability analysis (PVA. Results were alarming in the three studied wetlands, especially in the Albufera de Valencia, where only one breeding pair was found. The percentage of decrease of estimated pairs was similar in all wetlands: ca. 90% between 2005 and 2013. Results from the PVAs predicted a 90% probability of reaching the quasi–extinction threshold before 2024 or 2028 for the largest population of bearded reedling in the Valencia region, El Hondo, while for the Santa Pola population this threshold would be reached before 2016 or 2017. The parallel trend and generalized decline in the Spanish coastal wetlands suggests that these Mediterranean wetlands probably share some specific factors that have adversely affected its populations. Given that all these natural spaces are surrounded by intensively irrigated crops that are subjected to the intense use of pesticides, we hypothesize that these products could have had a detrimental effect on the bearded reedling. This hypothesis is supported by the fact that the healthiest populations are situated in Iberian inland wetlands that are surrounded by dry crops, where the use of pesticides is less intense. We propose cataloguing the species as Endangered at regional level.

Dramatic decline of the bearded reedling, Panurus biarmicus, in Spanish Mediterranean wetlands

Energy Technology Data Exchange (ETDEWEB)

Belenguer Barrionuevo, R.; Lopez-Iborra, G. M.; Dies, J.I.; Castany i Alvaro, J.

2016-07-01

The apparent stability of the bearded reedling in Spanish inland wetlands contrasts with its threatened status in Spanish coastal wetlands. The species has already disappeared from some coastal areas in Catalonia and its situation is critical in the region of Valencia. In 2013 we studied the breeding populations in three wetlands in Valencia using two methods: census by exhaustive search of individuals (territory mapping) and distance sampling using line transects. We estimated the trend of these populations from data obtained in previous censuses (2005 and 2006), and assessed their viability in the medium and short term using count–based population viability analysis (PVA). Results were alarming in the three studied wetlands, especially in the Albufera de Valencia, where only one breeding pair was found. The percentage of decrease of estimated pairs was similar in all wetlands: ca. 90% between 2005 and 2013. Results from the PVAs predicted a 90% probability of reaching the quasi–extinction threshold before 2024 or 2028 for the largest population of bearded reedling in the Valencia region, El Hondo, while for the Santa Pola population this threshold would be reached before 2016 or 2017. The parallel trend and generalized decline in the Spanish coastal wetlands suggests that these Mediterranean wetlands probably share some specific factors that have adversely affected its populations. Given that all these natural spaces are surrounded by intensively irrigated crops that are subjected to the intense use of pesticides, we hypothesize that these products could have had a detrimental effect on the bearded reedling. This hypothesis is supported by the fact that the healthiest populations are situated in Iberian inland wetlands that are surrounded by dry crops, where the use of pesticides is less intense. We propose cataloguing the species as Endangered at regional level. (Author)

Evaluation of wetlands designed to transfer and transform selected metals in an aqueous matrix

International Nuclear Information System (INIS)

Hawkins, W.B.; Gillespie, W.B. Jr.; Rodgers, J.H. Jr.

1995-01-01

Constructed wetlands can be used as an alternative to traditional wastewater treatment. Two wetlands were constructed at a Louisiana petroleum refinery and were used to study transfers and transformations of selected metals (Zn, Pb, and Cu) in a refinery effluent. In order to optimize metal removal from the aqueous matrix and subsequently decrease metal bioavailability, the hydroperiod, hydrosoil, and vegetation were specifically selected and incorporated into the wetland design. To test the metal removal efficiency of the constructed wetlands, refinery effluent was amended with 4 mg Zn/L as ZnCl 2 for 150 d. From influent to effluent, average total recoverable and soluble zinc concentrations decreased by 41 and 72%, respectively. Toxicity tests (7 d) using Ceriodaphnia dubia and Pimephales promelas illustrated a decrease in zinc bioavailability. Average C. dubia survival increased from 0--73% as a result of wetland treatment; for P. promelas, the increase in average survival was 37--94%. Based upon this field experiment, constructed wetlands can be specifically designed for zinc removal and concomitant decreases in toxicity

Effect of redox conditions on bacterial and fungal biomass and carbon dioxide production in Louisiana coastal swamp forest sediment

International Nuclear Information System (INIS)

Seo, Dong Cheol; DeLaune, Ronald D.

2010-01-01

Fungal and bacterial carbon dioxide (CO 2 ) production/emission was determined under a range of redox conditions in sediment from a Louisiana swamp forest used for wastewater treatment. Sediment was incubated in microcosms at 6 Eh levels (-200, -100, 0, + 100, + 250 and + 400 mV) covering the anaerobic range found in wetland soil and sediment. Carbon dioxide production was determined by the substrate-induced respiration (SIR) inhibition method. Cycloheximide (C 15 H 23 NO 4 ) was used as the fungal inhibitor and streptomycin (C 21 H 39 N 7 O 12 ) as the bacterial inhibitor. Under moderately reducing conditions (Eh > + 250 mV), fungi contributed more than bacteria to the CO 2 production. Under highly reducing conditions (Eh ≤ 0 mV), bacteria contributed more than fungi to the total CO 2 production. The fungi/bacteria (F/B) ratios varied between 0.71-1.16 for microbial biomass C, and 0.54-0.94 for microbial biomass N. Under moderately reducing conditions (Eh ≥ + 100 mV), the F/B ratios for microbial biomass C and N were higher than that for highly reducing conditions (Eh ≤ 0 mV). In moderately reducing conditions (Eh ≥ + 100 mV), the C/N microbial biomass ratio for fungi (C/N: 13.54-14.26) was slightly higher than for bacteria (C/N: 9.61-12.07). Under highly reducing redox conditions (Eh ≤ 0 mV), the C/N microbial biomass ratio for fungi (C/N: 10.79-12.41) was higher than for bacteria (C/N: 8.21-9.14). For bacteria and fungi, the C/N microbial biomass ratios under moderately reducing conditions were higher than that in highly reducing conditions. Fungal CO 2 production from swamp forest could be of greater ecological significance under moderately reducing sediment conditions contributing to the greenhouse effect (GHE) and the global warming potential (GWP). However, increases in coastal submergence associated with global sea level rise and resultant decrease in sediment redox potential from increased flooding would likely shift CO 2 production to bacteria

The dirt on sediments

Science.gov (United States)

Smith, Loren M.; Euliss, Ned H. "Chip"

2010-01-01

In the wetland science field, sediment deposition is often thought of as being beneficial especially when one thinks of coastal estuarine systems. For example, sediments deposited from streams and rivers are necessary to naturally build and maintain tidal marshes. These sediments come from eroded upland soils in the interior of the continent. When these sediments are diverted from natural coastal deposition areas, such as occurs from river channelization, we lose marshes through subsidence as is happening throughout coastal Louisiana. However, the value of eroded soils is all a matter of hydrogeomorphic perspective.

A brief review of remote sensing data and techniques for wetlands identification

CSIR Research Space (South Africa)

Ritchie, M

2015-09-01

Full Text Available of geoprocessing and simulation modeling to estimate impacts of sea level rise on the northeast coast of Florida, Photogrammetric Engineering and Remote Sensing, 58, 1579-1586. McEwan, R., Kosco, W. and Carter, V., 1976, Coastal Wetland Mapping..., it is estimated that about 33 230 acres of wetland were lost between 1998-2004 [Klemas 2011], with a majority of this loss being due to coastal salt marsh being converted to open saltwater [Klemas 2011], suggesting that rising sea levels could be problematic...

Hydrology of Fritchie Marsh, coastal Louisiana

Science.gov (United States)

Kuniansky, E.L.

1985-01-01

Fritchie Marsh, near Slidell, Louisiana, is being considered as a disposal site for sewage effluent. A two-dimensional, finite element, surface water modeling systems was used to solve the shallow water equations for flow. Factors affecting flow patterns are channel locations, inlets, outlets, islands, marsh vegetation, marsh geometry, stage of the West Pearl River, flooding over the lower Pearl River basin, gravity tides, wind-induced currents, and sewage discharge to the marsh. Four steady-state simulations were performed for two hydrologic events at two rates of sewage discharge. The events, near tide with no wind or rain and neap tide with a tide differential across the marsh, were selected as worst-case events for sewage effluent dispersion and were assumed as steady state events. Because inflows and outflows to the marsh are tidally affected, steady state simulations cannot fully define the hydraulic characteristics of the marsh for all hydrologic events. Model results and field data indicate that, during near tide with little or no rain, large parts of the marsh are stagnant; and sewage effluent, at existing and projected flows, has minimal effect on marsh flows. (USGS)

Ecological Effects of Roads on the Plant Diversity of Coastal Wetland in the Yellow River Delta

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Yunzhao Li

2014-01-01

Full Text Available The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of βT and Jaccard’s coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20 m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing β-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20 m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion.

Ecological Effects of Roads on the Plant Diversity of Coastal Wetland in the Yellow River Delta

Science.gov (United States)

Li, Yunzhao; Du, Siyao; Han, Guangxuan; Qu, Fanzhu; Wang, Guangmei; Fu, Yuqin; Zhan, Chao

2014-01-01

The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of β T and Jaccard's coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20 m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing β-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20 m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion. PMID:25147872

Tracing multi-habitat support of coastal fishes

Science.gov (United States)

Hydrologic linkages among coastal wetland and nearshore areas allow coastal fish to move among the habitats, which has led to a variety of habitat use patterns. In the Great Lakes, fine-scale microchemical analyses of yellow perch otoliths have revealed life-history categories th...

Modeling the Hydrologic Processes of a Depressional Forested Wetland in South Carolina, U.S.A.

Science.gov (United States)

Ge Sun; Timothy Callahan; Jennifer E. Pyzoha; Carl C. Trettin; Devendra M. Amatya

2004-01-01

Depressional forested wetlands or geographically isolated wetlands such as cypress swamps and Carolina bays are common land features in the Atlantic Coastal Plain of the southeastern US. Those wetlands play important roles in providing wildlife habitats, water quality improvement, and carbon sequestration. Great stresses have been imposed on those important ecosystems...

Organic Carbon and Trace Element Cycling in a River-Dominated Tidal Coastal Wetland System (Tampa Bay, FL, USA)

Science.gov (United States)

Moyer, R. P.; Smoak, J. M.; Engelhart, S. E.; Powell, C. E.; Chappel, A. R.; Gerlach, M. J.; Kemp, A.; Breithaupt, J. L.

2016-02-01

Tampa Bay is the largest open water, river-fed estuary in Florida (USA), and is characterized by the presence of both mangrove and salt marsh ecosystems. Both coastal wetland systems, and small rivers such as the ones draining into Tampa Bay have historically been underestimated in terms of their role in the global carbon and elemental cycles. Climate change and sea-level rise (SLR) are major threats in Tampa Bay and stand to disrupt hydrologic cycles, compromising sediment accumulation and the rate of organic carbon (OC) burial. This study evaluates organic carbon content, sediment accumulation, and carbon burial rates in salt marsh and mangrove ecosystems, along with measurements of fluxes of dissolved OC (DOC) and trace elements in the water column of the Little Manatee River (LMR) in Tampa Bay. The characterization of OC and trace elements in tidal rivers and estuaries is critical for quantitatively constraining these systems in local-to-regional scale biogeochemical budgets, and provide insight into biogeochemical processes occurring with the estuary and adjacent tidal wetlands. Material fluxes of DOC and trace elements were tied to discharge irrespective of season, and the estuarine habitats removed 15-65% of DOC prior to export to Tampa Bay and the Gulf of Mexico. Thus, material is available for cycling and burial within marsh and mangrove peats, however, LMR mangrove peats have higher OC content and burial rates than adjacent salt marsh peats. Sedimentary accretion rates in LMR marshes are not currently keeping pace with SLR, thus furthering the rapid marsh-to-mangrove conversions that have been seen in Tampa Bay over the past half-century. Additionally, wetlands in Tampa Bay tend to have a lower rate of carbon burial than other Florida tidal wetlands, demonstrating their high sensitivity to climate change and SLR.

New Orleans, Louisiana Coastal Digital Elevation Model

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions in the Gulf of Mexico....

How a clogged canal impacts ecological health in a tropical urban wetland ecosystem

Science.gov (United States)

The coastal city of San Juan, Puerto Rico is a tropical urban ecosystem interwoven among a series of interconnected bays, lagoons, canals, and mangrove wetlands. As the city has expanded, infilling and urban encroachment on what was previously mangrove wetland and open estuarine ...

Baseline coastal oblique aerial photographs collected from Calcasieu Lake, Louisiana, to Brownsville, Texas, September 9-10, 2008

Science.gov (United States)

Morgan, Karen L. M.; Karen A. Westphal,

2016-04-28

The U.S. Geological Survey (USGS), as part of the National Assessment of Coastal Change Hazards project, conducts baseline and storm-response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms (Morgan, 2009). On September 9-10, 2008, the USGS conducted an oblique aerial photographic survey from Calcasieu Lake, Louisiana, to Brownsville, Texas, aboard a Cessna C-210 (aircraft) at an altitude of 500 feet (ft) and approximately 1,000 ft offshore. This mission was flown to collect baseline data for assessing incremental changes of the beach and nearshore area, and the data can be used in the assessment of future coastal change.The photographs provided in this report are Joint Photographic Experts Group (JPEG) images. ExifTool was used to add the following to the header of each photo: time of collection, Global Positioning System (GPS) latitude, GPS longitude, keywords, credit, artist (photographer), caption, copyright, and contact information. The photograph locations are an estimate of the position of the aircraft at the time the photograph was taken and do not indicate the location of any feature in the images (see the Navigation Data page). These photographs document the state of the barrier islands and other coastal features at the time of the survey. Pages containing thumbnail images of the photographs, referred to as contact sheets, were created in 5-minute segments of flight time. These segments can be found on the Photos and Maps page. Photographs can be opened directly with any JPEG-compatible image viewer by clicking on a thumbnail on the contact sheet.In addition to the photographs, a Google Earth Keyhole Markup Language (KML) file is provided and can be used to view the images by clicking on the marker and then clicking on either the thumbnail or the link above the thumbnail. The KML file was created using the photographic navigation files. The KML file can be found in the kml folder.

Marsh loss due to cumulative impacts of Hurricane Isaac and the DWH oil spill in Louisiana

NARCIS (Netherlands)

Khanna, Shruti; Ferreira Dos Santos, M.J.; Shapiro, Kristen; Lay, Mui; Ustin, Susan L.

Coastal ecosystems are greatly endangered due to anthropogenic development and climate change. Multiple disturbances may erode the ability of a system to recover from stress if there is little time between disturbance events. We evaluated the ability of the saltmarshes in Barataria Bay, Louisiana,

Floral diversity in the wetlands of Ibeju-Lekki Area, Lagos, Nigeria ...

African Journals Online (AJOL)

Until very recently poor attention has been given to the management of wetlands in Nigeria despite their significance in the global food and water supply, energy needs and disaster management. Due to the rapid development of the Lagos coastal areas for commerce and industrial purposes, the natural coastal vegetation ...

Wetlands in a changing climate: Science, policy and management

Science.gov (United States)

Moomaw, William R.; Chmura, G.L.; Davies, Gillian T.; Finlayson, Max; Middleton, Beth A.; Natali, Sue M.; Perry, James; Roulet, Nigel; Sutton-Grier, Ariana

2018-01-01

Part 1 of this review synthesizes recent research on status and climate vulnerability of freshwater and saltwater wetlands, and their contribution to addressing climate change (carbon cycle, adaptation, resilience). Peatlands and vegetated coastal wetlands are among the most carbon rich sinks on the planet sequestering approximately as much carbon as do global forest ecosystems. Estimates of the consequences of rising temperature on current wetland carbon storage and future carbon sequestration potential are summarized. We also demonstrate the need to prevent drying of wetlands and thawing of permafrost by disturbances and rising temperatures to protect wetland carbon stores and climate adaptation/resiliency ecosystem services. Preventing further wetland loss is found to be important in limiting future emissions to meet climate goals, but is seldom considered. In Part 2, the paper explores the policy and management realm from international to national, subnational and local levels to identify strategies and policies reflecting an integrated understanding of both wetland and climate change science. Specific recommendations are made to capture synergies between wetlands and carbon cycle management, adaptation and resiliency to further enable researchers, policy makers and practitioners to protect wetland carbon and climate adaptation/resiliency ecosystem services.

Dynamic characteristics of soil respiration in Yellow River Delta wetlands, China

Science.gov (United States)

Wang, Xiao; Luo, Xianxiang; Jia, Hongli; Zheng, Hao

2018-02-01

The stable soil carbon (C) pool in coastal wetlands, referred to as "blue C", which has been extensively damaged by climate change and soil degradation, is of importance to maintain global C cycle. Therefore, to investigate the dynamic characteristics of soil respiration rate and evaluate C budgets in coastal wetlands are urgently. In this study, the diurnal and seasonal variation of soil respiration rate in the reed wetland land (RL) and the bare wetland land (BL) was measured in situ with the dynamic gas-infrared CO2 method in four seasons, and the factors impacted on the dynamic characteristics of soil respiration were investigated. The results showed that the diurnal variation of soil respiration rate consistently presented a "U" curve pattern in April, July, and September, with the maximum values at 12:00 a.m. and the minimum values at 6:00 a.m. In the same season, the diurnal soil respiration rate in RL was significantly greater than those in BL (P respiration rate was 0.14, 0.42, and 0.39 μmol m-2 s-1 in RL, 0.05, 0.22, 0.13, and 0.01 μmol m-2 s-1 in BL, respectively. Soil surface temperature was the primary factor that influenced soil respiration, which was confirmed by the exponential positive correlation between the soil respiration rate and soil surface temperature in BL and RL (P respiration, confirming by the significantly negative correlation between soil respiration rate and the content of soluble salt. These results will be useful for understanding the mechanisms underlying soil respiration and elevating C sequestration potential in the coastal wetlands.

Review of the Distribution of Waterbirds in Two Tropical coastal

African Journals Online (AJOL)

Administrator

Areview of waterbirds was undertaken in two coastal Ramsar lagoons, namely the Keta and Muni Ramsar ... waterbirds, the East Atlantic Flyway and the ... In fact, Ghana‟s coastal wetlands are ...... such as mangrove forests, which serve as.

Restoring Tides to Avoid Methane Emissions in Degraded Wetlands: A Potent and Untapped Climate Intervention

Science.gov (United States)

Kroeger, K. D.; Crooks, S.; Moseman-Valtierra, S.; Tang, J.

2016-12-01

To date, activity related to carbon (C) management in coastal marine ecosystems (sometimes referred to as "Blue Carbon") has been concerned primarily with preserving existing C stocks or creating new wetlands to increase CO2 uptake and sequestration. Here we show that the globally-widespread occurrence of hydrologically-altered, degraded wetlands, and associated enhanced GHG emissions, presents an opportunity to reduce an anthropogenic GHG emission through restoration. We model the climatic forcing associated with carbon sinks in natural wetlands and with GHG emissions in altered and degraded wetlands, as well as compile geographic data on tidal restrictions to show that substantial methane (CH4) and CO2 emission reductions can be achieved through restoration of saline tidal flows in diked, impounded and tidally-restricted coastal wetlands. Despite high rates of carbon storage in coastal ecosystems, tidal restoration has dramatically greater potential per unit area as a climate intervention than most other ecosystem management actions. We argue that such emissions reductions represent avoided anthropogenic emissions, equivalent in concept to reduced fossil fuel emissions. Once the emissions have been avoided, the benefit of that action cannot be eliminated, even if emissions resume in the future due to degradation of the ecosystem. The avoided emissions therefore have inherent "permanence", obviating concerns associated with vulnerability of C stocks in land-use based interventions that enhance C sequestration in wood or soil. Further, emissions reductions are likely to be rapid, and given the high radiative efficiency of avoided CH4, wetland tidal restorations can provide near-term climate benefit. The U.S. has recently initiated an effort to include coastal wetlands in the Inventory of U.S. Greenhouse Gas Emissions and Sinks, and the analysis presented here indicates that tidally restricted wetlands meet the primary criteria for inventoried ecosystems in that

How a clogged canal effects ecological and human health in a tropical urban wetland ecosystem

Science.gov (United States)

The coastal city of San Juan, Puerto Rico is a tropical urban ecosystem interwoven among a series of interconnected bays, lagoons, canals, and mangrove wetlands. As the city has expanded, infilling and urban encroachment on what was previously mangrove wetland and open estuarine ...

Monitoring man's impact in the coastal zone

International Nuclear Information System (INIS)

Benton, A.R. Jr.; Snell, W.W.

1979-01-01

The paper examines the monitoring of man's impact in the coastal zone. Color infrared photography shows destroyed or degraded wetlands or beaches, and makes possible relevant linear or aerial measurements with aerial photography. It can also categorize the environmental impacts which have accrued as the result of completion of water development projects. Aerial photography of the Texas coastal zone illustrates the nature and degree of damage likely to occur as a result of construction or maintenance projects. It is concluded that the method of assigning realistic values to unit areas of wetlands and beaches will make it feasible to incorporate the cost of estuarine damages into the cost estimates of water development schemes

Chinese Tallow (Triadica sebifera (L.) Small) Population expansion in Louisiana, East Texas, and Mississippi

Science.gov (United States)

Sonja N. Oswalt

2010-01-01

Chinese tallow (Triadica sebifera) is a nonnative invasive species with high fecundity rates that has naturalized from the coastal prairies of east Texas along the Gulf and Atlantic coasts as far north as North Carolina. Population differences were computed for two forest inventory periods (mid-1990s and late 2000s) in Louisiana, east Texas, and Mississippi using data...

Changing Course: navigating the future of the Lower Mississippi River

Science.gov (United States)

Cochran, S.

2016-02-01

Changing Course is a design competition to reimagine a more sustainable Lower Mississippi River Delta, bringing teams together from around the world to create innovative visions for one of America's greatest natural resources. Building off of Louisiana's Coastal Master Plan, and answering a key question from that plan, three winning teams (Baird & Associates, Moffatt & Nichol and Studio Misi-Ziibi) have generated designs for how the Mississippi River's water and sediment can be used to maximize rebuilding of delta wetlands while also continuing to meet the needs of navigation, flood protection, and coastal industries and communities. While each of the winning teams offered a different vision, all three identified the same key requirements as critical to sustaining the Mississippi River Delta today and into the future: Reconnecting the Mississippi River to its wetlands to help restore southeast Louisiana's first line of defense against powerful storms and rising sea levels. Planning for a more sustainable delta, including a gradual shift in population to create more protected and resilient communities. Protecting and maximizing the region's port and maritime activities, including a deeper more sustainable navigation channel upriver from Southwest Pass. Increasing economic opportunities in a future smaller delta through expanding shipping capacity, coastal restoration infrastructure, outdoor recreation and tourism and commercial fishing. This session will give a high level overview of the design competition process, results and common themes, similarities and differences in their designs, and how the ideas generated will inform coastal stakeholders and official government processes.

Geomorphic and ecological effects of Hurricanes Katrina and Rita on coastal Louisiana marsh communities

Science.gov (United States)

Piazza, Sarai C.; Steyer, Gregory D.; Cretini, Kari F.; Sasser, Charles E.; Visser, Jenneke M.; Holm, Guerry O.; Sharp, Leigh A.; Evers, D. Elaine; Meriwether, John R.

2011-01-01

Hurricanes Katrina and Rita made landfall in 2005, subjecting the coastal marsh communities of Louisiana to various degrees of exposure. We collected data after the storms at 30 sites within fresh (12), brackish/intermediate (12), and saline (6) marshes to document the effects of saltwater storm surge and sedimentation on marsh community dynamics. The 30 sites were comprised of 15 pairs. Most pairs contained one site where data collection occurred historically (that is, prestorms) and one Coastwide Reference Monitoring System site. Data were collected from spring 2006 to fall 2007 on vegetative species composition, percentage of vegetation cover, aboveground and belowground biomass, and canopy reflectance, along with discrete porewater salinity, hourly surface-water salinity, and water level. Where available, historical data acquired before Hurricanes Katrina and Rita were used to compare conditions and changes in ecological trajectories before and after the hurricanes. Sites experiencing direct and indirect hurricane influences (referred to in this report as levels of influence) were also identified, and the effects of hurricane influence were tested on vegetation and porewater data. Within fresh marshes, porewater salinity was greater in directly impacted areas, and this heightened salinity was reflected in decreased aboveground and belowground biomass and increased cover of disturbance species in the directly impacted sites. At the brackish/intermediate marsh sites, vegetation variables and porewater salinity were similar in directly and indirectly impacted areas, but porewater salinity was higher than expected throughout the study. Interestingly, directly impacted saline marsh sites had lower porewater salinity than indirectly impacted sites, but aboveground biomass was greater at the directly impacted sites. Because of the variable and site-specific nature of hurricane influences, we present case studies to help define postdisturbance baseline conditions in

Relating groundwater to seasonal wetlands in southeastern Wisconsin, USA

Science.gov (United States)

Skalbeck, J.D.; Reed, D.M.; Hunt, R.J.; Lambert, J.D.

2009-01-01

Historically, drier types of wetlands have been difficult to characterize and are not well researched. Nonetheless, they are considered to reflect the precipitation history with little, if any, regard for possible relation to groundwater. Two seasonal coastal wetland types (wet prairie, sedge meadow) were investigated during three growing seasons at three sites in the Lake Michigan Basin, Wisconsin, USA. The six seasonal wetlands were characterized using standard soil and vegetation techniques and groundwater measurements from the shallow and deep systems. They all met wetland hydrology criteria (e.g., water within 30 cm of land surface for 5% of the growing season) during the early portion of the growing season despite the lack of appreciable regional groundwater discharge into the wetland root zones. Although root-zone duration analyses did not fit a lognormal distribution previously noted in groundwater-dominated wetlands, they were able to discriminate between the plant communities and showed that wet prairie communities had shorter durations of continuous soil saturation than sedge meadow communities. These results demonstrate that the relative rates of groundwater outflows can be important for wetland hydrology and resulting wetland type. Thus, regional stresses to the shallow groundwater system such as pumping or low Great Lake levels can be expected to affect even drier wetland types. ?? Springer-Verlag 2008.

Essential coastal habitats for fish in the Baltic Sea

DEFF Research Database (Denmark)

Kraufvelin, Patrik; Pekcan-Hekim, Zeynep; Bergström, Ulf

2018-01-01

Many coastal and offshore fish species are highly dependent on specific habitat types for population maintenance. In the Baltic Sea, shallow productive habitats in the coastal zone such as wetlands, vegetated flads/lagoons and sheltered bays as well as more exposed rocky and sandy areas are utili...

Ghost forest creation and the conversion of uplands to wetlands

Science.gov (United States)

Kirwan, M. L.; Schieder, N. W.; Reay, W.

2017-12-01

Global sea level rise rates began accelerating sharply in the late 19th century, with an approximate tripling in sea level rise rates in many regions of the world. Some portions of the coastal landscape, such as marshes and barrier islands, survive relative sea level rise by natural eco-geomorphic processes that allow them to build elevation vertically and migrate landward. In contrast, adjacent uplands typically occupied by forests and agricultural fields have limited ability to resist the impacts of sea level rise. This portion of the coastal landscape consists of mostly salt intolerant plants, receives little mineral sediment deposition, and rarely builds elevation through the accumulation of soil organic matter. Thus, ghost forests- dead trees surrounded by marshland- are a prominent feature of many low-relief coastal landscapes, and represent a striking visual indicator of upland to wetland conversion. Here, we report preliminary results of several efforts designed to quantify rates and drivers of upland to wetland conversion in the mid-Atlantic region of the United States. Drone based canopy monitoring and ground-based seedling experiments suggest that ghost forests are created by episodic, storm-driven adult tree mortality paired with continuous seedling mortality. Preliminary comparisons between sediment cores and historical photographs from 5 sites in Maryland, Virginia, and North Carolina suggest that modern coastal forest retreat is 2-10 times faster than late-Holocene retreat rates, and that rates have accelerated in most decades since the 1930's. Finally, historical T-Sheet maps suggest that approximately 100,000 acres (400 km2) of uplands have converted to wetlands in the Chesapeake region, and that about 1/3 of all present-day marsh was created by upland drowning since the late 19th Century. Together, these observations indicate rapid coastal transgression, where low-relief, terrestrial portions of the coastal landscape are perhaps more sensitive to

Wetlands in changed landscapes: the influence of habitat transformation on the physico-chemistry of temporary depression wetlands.

Science.gov (United States)

Bird, Matthew S; Day, Jenny A

2014-01-01

Temporary wetlands dominate the wet season landscape of temperate, semi-arid and arid regions, yet, other than their direct loss to development and agriculture, little information exists on how remaining wetlands have been altered by anthropogenic conversion of surrounding landscapes. This study investigates relationships between the extent and type of habitat transformation around temporary wetlands and their water column physico-chemical characteristics. A set of 90 isolated depression wetlands (seasonally inundated) occurring on coastal plains of the south-western Cape mediterranean-climate region of South Africa was sampled during the winter/spring wet season of 2007. Wetlands were sampled across habitat transformation gradients according to the areal cover of agriculture, urban development and alien invasive vegetation within 100 and 500 m radii of each wetland edge. We hypothesized that the principal drivers of physico-chemical conditions in these wetlands (e.g. soil properties, basin morphology) are altered by habitat transformation. Multivariate multiple regression analyses (distance-based Redundancy Analysis) indicated significant associations between wetland physico-chemistry and habitat transformation (overall transformation within 100 and 500 m, alien vegetation cover within 100 and 500 m, urban cover within 100 m); although for significant regressions the amount of variation explained was very low (range: ∼2 to ∼5.5%), relative to that explained by purely spatio-temporal factors (range: ∼35.5 to ∼43%). The nature of the relationships between each type of transformation in the landscape and individual physico-chemical variables in wetlands were further explored with univariate multiple regressions. Results suggest that conservation of relatively narrow (∼100 m) buffer strips around temporary wetlands is likely to be effective in the maintenance of natural conditions in terms of physico-chemical water quality.

Wetlands in changed landscapes: the influence of habitat transformation on the physico-chemistry of temporary depression wetlands.

Directory of Open Access Journals (Sweden)

Matthew S Bird

Full Text Available Temporary wetlands dominate the wet season landscape of temperate, semi-arid and arid regions, yet, other than their direct loss to development and agriculture, little information exists on how remaining wetlands have been altered by anthropogenic conversion of surrounding landscapes. This study investigates relationships between the extent and type of habitat transformation around temporary wetlands and their water column physico-chemical characteristics. A set of 90 isolated depression wetlands (seasonally inundated occurring on coastal plains of the south-western Cape mediterranean-climate region of South Africa was sampled during the winter/spring wet season of 2007. Wetlands were sampled across habitat transformation gradients according to the areal cover of agriculture, urban development and alien invasive vegetation within 100 and 500 m radii of each wetland edge. We hypothesized that the principal drivers of physico-chemical conditions in these wetlands (e.g. soil properties, basin morphology are altered by habitat transformation. Multivariate multiple regression analyses (distance-based Redundancy Analysis indicated significant associations between wetland physico-chemistry and habitat transformation (overall transformation within 100 and 500 m, alien vegetation cover within 100 and 500 m, urban cover within 100 m; although for significant regressions the amount of variation explained was very low (range: ∼2 to ∼5.5%, relative to that explained by purely spatio-temporal factors (range: ∼35.5 to ∼43%. The nature of the relationships between each type of transformation in the landscape and individual physico-chemical variables in wetlands were further explored with univariate multiple regressions. Results suggest that conservation of relatively narrow (∼100 m buffer strips around temporary wetlands is likely to be effective in the maintenance of natural conditions in terms of physico-chemical water quality.

Environmental assessment of proposed geothermal well testing in the Tigre Lagoon Oil Field, Vermilion Parish, Louisiana

Energy Technology Data Exchange (ETDEWEB)

1976-03-01

An environmental assessment is made of the proposed testing of two geopressured, geothermal aquifers in central coastal Louisiana. On the basis of an analysis of the environmental setting, subsurface characteristics, and the proposed action, potential environmental impacts are determined and evaluated together with potential conflicts with federal, state, and local programs. (LBS )

Surrounding land cover types as predictors of palustrine wetland vegetation quality in conterminous USA

Science.gov (United States)

Stapanian, Martin A.; Gara, Brian; Schumacher, William

2018-01-01

The loss of wetland habitats and their often-unique biological communities is a major environmental concern. We examined vegetation data obtained from 380 wetlands sampled in a statistical survey of wetlands in the USA. Our goal was to identify which surrounding land cover types best predict two indices of vegetation quality in wetlands at the regional scale. We considered palustrine wetlands in four regions (Coastal Plains, North Central East, Interior Plains, and West) in which the dominant vegetation was emergent, forested, or scrub-shrub. For each wetland, we calculated weighted proportions of eight land cover types surrounding the area in which vegetation was assessed, in four zones radiating from the edge of the assessment area to 2 km. Using Akaike's Information Criterion, we determined the best 1-, 2- and 3-predictor models of the two indices, using the weighted proportions of the land cover types as potential predictors. Mean values of the two indices were generally higher in the North Central East and Coastal Plains than the other regions for forested and emergent wetlands. In nearly all cases, the best predictors of the indices were not the dominant surrounding land cover types. Overall, proportions of forest (positive effect) and agriculture (negative effect) surrounding the assessment area were the best predictors of the two indices. One or both of these variables were included as predictors in 65 of the 72 models supported by the data. Wetlands surrounding the assessment area had a positive effect on the indices, and ranked third (33%) among the predictors included in supported models. Development had a negative effect on the indices and was included in only 28% of supported models. These results can be used to develop regional management plans for wetlands, such as creating forest buffers around wetlands, or to conserve zones between wetlands to increase habitat connectivity.

Delineation of marsh types and marsh-type change in coastal Louisiana for 2007 and 2013

Science.gov (United States)

Hartley, Stephen B.; Couvillion, Brady R.; Enwright, Nicholas M.

2017-05-30

The Bureau of Ocean Energy Management researchers often require detailed information regarding emergent marsh vegetation types (such as fresh, intermediate, brackish, and saline) for modeling habitat capacities and mitigation. In response, the U.S. Geological Survey in cooperation with the Bureau of Ocean Energy Management produced a detailed change classification of emergent marsh vegetation types in coastal Louisiana from 2007 and 2013. This study incorporates two existing vegetation surveys and independent variables such as Landsat Thematic Mapper multispectral satellite imagery, high-resolution airborne imagery from 2007 and 2013, bare-earth digital elevation models based on airborne light detection and ranging, alternative contemporary land-cover classifications, and other spatially explicit variables. An image classification based on image objects was created from 2007 and 2013 National Agriculture Imagery Program color-infrared aerial photography. The final products consisted of two 10-meter raster datasets. Each image object from the 2007 and 2013 spatial datasets was assigned a vegetation classification by using a simple majority filter. In addition to those spatial datasets, we also conducted a change analysis between the datasets to produce a 10-meter change raster product. This analysis identified how much change has taken place and where change has occurred. The spatial data products show dynamic areas where marsh loss is occurring or where marsh type is changing. This information can be used to assist and advance conservation efforts for priority natural resources.

Sediment Transport and Slope Stability of Ship Shoal Borrow Areas for Coastal Restoration of Louisiana

Science.gov (United States)

Liu, H.; Xu, K.; Bentley, S. J.; Li, C.; Miner, M. D.; Wilson, C.; Xue, Z.

2017-12-01

Sandy barrier islands along Louisiana coast are degrading rapidly due to both natural and anthropogenic factors. Ship Shoal is one of the largest offshore sand resources, and has been used as a borrow area for Caminada Headland Restoration Project. Our knowledge of sediment transport and infilling processes in this new sandy and dynamic borrow area is rather limited. High resolution sub-bottom seismic data, side scan sonar images, multi-beam bathymetry and laser sediment grain size data were used to study seafloor morphological evolution and pit wall stability in response to both physical and geological processes. The multi-beam bathymetry and seismic profiling inside the pit showed that disequilibrium conditions led to rapid infilling in the pits at the beginning, but this process slowed down after the pit slope became stable and topography became smooth. We hypothesize that the erosion of the adjacent seabed sediment by energetic waves and longshore currents, the supply of suspended sediment from the rivers, and the erodible materials produced by local mass wasting on pit walls are three main types of infilling sediments. Compared with mud-capped dredge pits, this sandy dredge pit seems to have more gentle slopes on pit walls, which might be controlled by the angle of repose. Infilling sediment seems to be dominantly sandy, with some mud patches on bathymetric depressions. This study helps us better understand the impacts of mining sediment for coastal restoration and improves sand resource management efforts.

Corrosion Map for Metal Pipes in Coastal Louisiana

Science.gov (United States)

2017-12-01

Transportation agencies often allow metal pipes as an option for cross drains under/along roads and highways. Metal culverts can corrode over time at various rates based on their environmental conditions (e.g., corrosive nature of coastal soils, high...

Climatic change and variability: The effects of an altered water regime on Great Lakes coastal wetlands

International Nuclear Information System (INIS)

Mortsch, L.

1990-01-01

Wetlands of Canada are disappearing at a rapid rate due to urban encroachment and agricultural land drainage. Climatic change may be another threat to their continued viability. Wetlands perform numerous functions such as providing wildlife habitat, enhancing water quality, providing recreation opportunities and supporting commercial activities. Impact scenarios of global warming on Great Lakes hydrology and wetland ecosystem response to water level changes are tabulated. Wetland response to lower annual water levels depends on the type of wetland, its geomorphology and bathymetry. Marshes and open water wetland adapt more readily to lower levels than swamps. Swamps are less resilient since trees cannot regenerate and colonize quickly. Enclosed and barrier beach wetlands are more prone to drying out and loosing wetland vegetation during low water periods. In open shoreline wetlands, the areal extent could increase if there is a gentle slope and other suitable conditions. Precambrian Shield wetlands are located in areas of irregular slope and rocky substrate, and would have fewer sites for successful colonization. 15 refs., 2 tabs

Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise

Science.gov (United States)

Cherry, J.A.; McKee, K.L.; Grace, J.B.

2009-01-01

1. Sea-level rise, one indirect consequence of increasing atmospheric CO2, poses a major challenge to long-term stability of coastal wetlands. An important question is whether direct effects of elevated CO 2 on the capacity of marsh plants to accrete organic material and to maintain surface elevations outweigh indirect negative effects of stressors associated with sea-level rise (salinity and flooding). 2. In this study, we used a mesocosm approach to examine potential direct and indirect effects of atmospheric CO2 concentration, salinity and flooding on elevation change in a brackish marsh community dominated by a C3 species, Schoenoplectus americanus, and a C4 grass, Spartina patens. This experimental design permitted identification of mechanisms and their role in controlling elevation change, and the development of models that can be tested in the field. 3. To test hypotheses related to CO2 and sea-level rise, we used conventional anova procedures in conjunction with structural equation modelling (SEM). SEM explained 78% of the variability in elevation change and showed the direct, positive effect of S. americanus production on elevation. The SEM indicated that C3 plant response was influenced by interactive effects between CO2 and salinity on plant growth, not a direct CO2 fertilization effect. Elevated CO2 ameliorated negative effects of salinity on S. americanus and enhanced biomass contribution to elevation. 4. The positive relationship between S. americanus production and elevation change can be explained by shoot-base expansion under elevated CO 2 conditions, which led to vertical soil displacement. While the response of this species may differ under other environmental conditions, shoot-base expansion and the general contribution of C3 plant production to elevation change may be an important mechanism contributing to soil expansion and elevation gain in other coastal wetlands. 5. Synthesis. Our results revealed previously unrecognized interactions and

Modeling the climatic and subsurface stratigraphy controls on the hydrology of a Carolina bay wetland in South Carolina, USA

Science.gov (United States)

Ge Sun; Timothy J. Callahan; Jennifer E. Pyzoha; Carl C. Trettin

2006-01-01

Restoring depressional wetlands or geographically isolated wetlands such as cypress swamps and Carolina bays on the Atlantic Coastal Plains requires a clear understanding of the hydrologic processes and water balances. The objectives of this paper are to (1) test a distributed forest hydrology model, FLATWOODS, for a Carolina bay wetland system using seven years of...

Modeling the climatic and subsurface stratigraphy controls on the hydrology of a Carolina Bay wetland in South Carolina, USA

Science.gov (United States)

Ge Sun; Timothy J. Callahan; Jennifer E. Pyzoha; Carl C. Trettin

2006-01-01

Restoring depressional wetlands or geographically isolated wetlands such as cypress swamps and Carolina bays on the Atlantic Coastal Plains requires a clear understanding of the hydrologic processes and water balances. The objectives of this paper are to (1) test a distributed forest hydrology model, FLATWOODS, for a Carolina bay wetland system using seven years of...

The mangrove tangle: short-term bio-physical interactions in coastal mangroves

NARCIS (Netherlands)

Horstman, Erik

2014-01-01

Mangroves are coastal wetland ecosystems in the upper intertidal area. Salt-tolerant mangrove vegetation dwells on fine substrates in sheltered, low-energy coastal environments such as estuaries and lagoons. At the interface between land and sea, mangroves provide a plethora of regulating, habitat

Study on Ecological Risk Assessment of Guangxi Coastal Zone Based on 3s Technology

Science.gov (United States)

Zhong, Z.; Luo, H.; Ling, Z. Y.; Huang, Y.; Ning, W. Y.; Tang, Y. B.; Shao, G. Z.

2018-05-01

This paper takes Guangxi coastal zone as the study area, following the standards of land use type, divides the coastal zone of ecological landscape into seven kinds of natural wetland landscape types such as woodland, farmland, grassland, water, urban land and wetlands. Using TM data of 2000-2015 such 15 years, with the CART decision tree algorithm, for analysis the characteristic of types of landscape's remote sensing image and build decision tree rules of landscape classification to extract information classification. Analyzing of the evolution process of the landscape pattern in Guangxi coastal zone in nearly 15 years, we may understand the distribution characteristics and change rules. Combined with the natural disaster data, we use of landscape index and the related risk interference degree and construct ecological risk evaluation model in Guangxi coastal zone for ecological risk assessment results of Guangxi coastal zone.

Remote sensing and aerial photography for delineation and management of coastal ecosystems

Digital Repository Service at National Institute of Oceanography (India)

Jagtap, T.G.

sensing data. may provide necessary information to the planners and researchers. interested in the 11 .. coastal ecosystems. Mismanagement or lack of management of coastal zones may result in the loss of marine ecosystems, influencing erosion and the sea..., topographic maps and other resources. The effective management and research of coastal zones, require information on coastal landforms, wetlands, shoreline changes, sediment and current pattern, which can easily be obtained from the satellite data. Coastal...

Soil physicochemical conditions, denitrification rates, and nosZ abundance in North Carolina Coastal Plain restored wetlands

Science.gov (United States)

Ever since the United States adopted a national policy of wetland “No Net Loss”, a variety of measures have been aimed at restoring wetland biogeochemical function to former wetland areas. Nitrogen is a key element controlled by properly functioning wetlands, particularly when they are located adjac...

Preface: Remote Sensing in Coastal Environments

Directory of Open Access Journals (Sweden)

Deepak R. Mishra

2016-08-01

Full Text Available The Special Issue (SI on “Remote Sensing in Coastal Environments” presents a wide range of articles focusing on a variety of remote sensing models and techniques to address coastal issues and processes ranging for wetlands and water quality to coral reefs and kelp habitats. The SI is comprised of twenty-one papers, covering a broad range of research topics that employ remote sensing imagery, models, and techniques to monitor water quality, vegetation, habitat suitability, and geomorphology in the coastal zone. This preface provides a brief summary of each article published in the SI.

Phosphorus sorption-desorption and effects of temperature, pH and salinity on phosphorus sorption in marsh soils from coastal wetlands with different flooding conditions.

Science.gov (United States)

Bai, Junhong; Ye, Xiaofei; Jia, Jia; Zhang, Guangliang; Zhao, Qingqing; Cui, Baoshan; Liu, Xinhui

2017-12-01

Wetland soils act as a sink or source of phosphorus (P) to the overlaying water due to phosphorus sorption-desorption processes. Litter information is available on sorption and desorption behaviors of phosphorus in coastal wetlands with different flooding conditions. Laboratory experiments were conducted to investigate phosphorus sorption-desorption processes, fractions of adsorbed phosphorus, and the effects of salinity, pH and temperature on phosphorus sorption on soils in tidal-flooding wetlands (TW), freshwater-flooding wetlands (FW) and seasonal-flooding wetlands (SW) in the Yellow River Delta. Our results showed that the freshly adsorbed phosphorus dominantly exists in Occluded-P and Fe/AlP and their percentages increased with increasing phosphorus adsorbed. Phosphorus sorption isotherms could be better described by the modified Langmuir model than by the modified Freundlich model. A binomial equation could be properly used to describe the effects of salinity, pH, and temperature on phosphorus sorption. Phosphorus sorption generally increased with increasing salinity, pH, and temperature at lower ranges, while decreased in excess of some threshold values. The maximum phosphorus sorption capacity (Q max ) was larger for FW soils (256 mg/kg) compared with TW (218 mg/kg) and SW soils (235 mg/kg) (p < 0.05). The percentage of phosphorus desorption (P des ) in the FW soils (7.5-63.5%) was much lower than those in TW (27.7-124.9%) and SW soils (19.2-108.5%). The initial soil organic matter, pH and the exchangeable Al, Fe and Cd contents were important factors influencing P sorption and desorption. The findings of this study indicate that freshwater restoration can contribute to controlling the eutrophication status of water bodies through increasing P sorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

EAARL coastal topography and imagery–Western Louisiana, post-Hurricane Rita, 2005: First surface

Science.gov (United States)

Bonisteel-Cormier, Jamie M.; Wright, Wayne C.; Fredericks, Alexandra M.; Klipp, Emily S.; Nagle, Doug B.; Sallenger, Asbury H.; Brock, John C.

2013-01-01

These remotely sensed, geographically referenced color-infrared (CIR) imagery and elevation measurements of lidar-derived first-surface (FS) topography datasets were produced by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, Virginia. This project provides highly detailed and accurate datasets of a portion of the Louisiana coastline beachface, acquired post-Hurricane Rita on September 27-28 and October 2, 2005. The datasets are made available for use as a management tool to research scientists and natural-resource managers. An innovative airborne lidar instrument originally developed at the National Aeronautics and Space Administration (NASA) Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multispectral color-infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for sub-meter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL

Assessment of Remote Sensing Products and Hydrologic Simulation of the 2016 Louisiana Flood in the Amite River Basin

Science.gov (United States)

Gao, S.; Bilskie, M. V.; Hagen, S. C.; Braud, D.

2017-12-01

Riverine and coastal flooding are one of the most common environmental hazards that affect millions of people around the world. For example, in August 2016, a slow-moving upper level low-pressure system with a high amount of atmospheric moisture brought heavy rains from August 11 to August 13. The torrential downpours led to widespread flash flooding and river flooding across multiple parishes in Southeast Louisiana and Southwest Mississippi (NWS, 2016; Watson et al., 2017). Precipitation totals as high as 26 inches were recorded during the two-day event. A Louisiana Economic Development report documented that the state of Louisiana suffered more than eight billion dollars in damage from the catastrophic flooding (LED, 2016). According to the National Weather Service (NWS) in New Orleans, the rainfall caused the Amite River, Comite River, Tangipahoa River and Tickfaw River to rise to record-setting levels. Some of the most serious flooding occurred along the Amite River, which runs between Baton Rouge and the nearby city of Denham Springs, and has its headwaters in southwestern Mississippi and drains into Lake Maurepas (Mossa et al., 1997). To develop an understanding of the driving mechanisms that caused the catastrophic flooding a campaign was initiated to collect and rigorously examine all possible remote sensing products in order to derive the flooding extent and depth within the Amite River basin. In addition, a Soil and Water Assessment Tool (SWAT) has been developed for the Amite River watershed to simulate runoff from the 2016 Louisiana flood event. The developed and assimilated remote sensing and modeling products will enhance understanding of the hydrological processes within the Amite River basin. This will provide further insight into conceptualization of flood risk across river deltas that are vulnerable to both riverine and coastal flooding. Reference:LED. (2016). The economic impact of the august 2016 floods on the state of Louisiana. Mossa, J., & Mc

Coastal ecosystems for protection against storm surge

Digital Repository Service at National Institute of Oceanography (India)

Mascarenhas, A.

and infrastructure in single catastrophe exceeded Rs. 2750 crore. Economic loss is thus prohibitive and hence unsustainable. This paper acknowledges the intrinsic protective value of coastal sand dunes, vegetation and wetlands as a functional natural defence...

Influence of Black Mangrove Expansion on Salt Marsh Food Web Dynamics in Coastal Louisiana

Science.gov (United States)

Powell, C.; Baustian, M. M.; Polito, M. J.

2017-12-01

The range of black mangroves (Avicennia germinans) is projected to expand in the northern Gulf of Mexico due to reduced winter freeze events and an increased rate of droughts. The colonization of mangroves in salt marshes alters habitat structure and creates a novel basal carbon source for consumers. This addition may modify trophic linkages and the structure of estuarine food webs. To understand the implications of mangrove expansion on food web dynamics of traditional Spartina alterniflora marshes, two sites in coastal Louisiana with three habitat types, marsh-dominated, mangrove-dominated, and a transition or mix of the two, were studied. Community composition of juvenile nekton was sampled using fyke nets, minnow traps, and suction sampling and analyzed for abundance and diversity. Primary carbon sources (emergent vegetation, phytoplankton, macroalgae, benthic microalgae, submerged aquatic vegetation, and soil organic matter) and consumers ((blue crabs (Callinectes sapidus), brown shrimp (Farfantepenaeus aztecus), grass shrimp (Palaemonetes spp.), Gulf killifish (Fundulus grandis), periwinkle snails (Littoraria irrorata), eastern oysters (Crassostrea virginica), and southern ribbed mussels (Geukensia granosissima)) collected at each habitat type were measured using stable isotope analysis (δ13C, δ15N, δ34S) to identify trophic level, basal carbon sources, and assess how mangrove carbon is incorporated into salt marsh food webs. While data analysis is ongoing, preliminary results indicate that basal carbon sources supporting some marsh consumers (e.g., periwinkle snails) shift between habitat types, while others remain static (e.g., grass shrimp). This research will further develop our understanding of how climate induced shifts in vegetation influences valued marsh-dependent consumers in the estuarine ecosystems of northern Gulf of Mexico.

STUDY ON ECOLOGICAL RISK ASSESSMENT OF GUANGXI COASTAL ZONE BASED ON 3S TECHNOLOGY

Directory of Open Access Journals (Sweden)

Z. Zhong

2018-05-01

Full Text Available This paper takes Guangxi coastal zone as the study area, following the standards of land use type, divides the coastal zone of ecological landscape into seven kinds of natural wetland landscape types such as woodland, farmland, grassland, water, urban land and wetlands. Using TM data of 2000–2015 such 15 years, with the CART decision tree algorithm, for analysis the characteristic of types of landscape’s remote sensing image and build decision tree rules of landscape classification to extract information classification. Analyzing of the evolution process of the landscape pattern in Guangxi coastal zone in nearly 15 years, we may understand the distribution characteristics and change rules. Combined with the natural disaster data, we use of landscape index and the related risk interference degree and construct ecological risk evaluation model in Guangxi coastal zone for ecological risk assessment results of Guangxi coastal zone.

A Model for Wetland Hydrology: Description and Validation

Science.gov (United States)

R.S. Mansell; S.A. Bloom; Ge Sun

2000-01-01

WETLANDS, a multidimensional model describing water flow in variably saturated soil and evapotranspiration, was used to simulate successfully 3-years of local hydrology for a cypress pond located within a relatively flat Coastal Plain pine forest landscape. Assumptions included negligible net regional groundwater flow and radially symmetric local flow impinging on a...

Early Maori settlement impacts in northern coastal Taranaki, New Zealand

International Nuclear Information System (INIS)

Wilmshurst, J.M.; Higham, T.F.G.; Allen, H.; Johns, D.; Phillips, C.

2004-01-01

Pollen and charcoal analyses of sediments from northern coastal Taranaki, New Zealand, show that Maori settlement impacts on the vegetation began with the burning of tall coastal forest in the mid-17th century. Forest was replaced with a fern-shrubland, and small wetlands expanded with changing hydrological conditions. This forest clearance was much later than in most regions of the country, where major forest disturbance and clearance began between AD 1200 and AD 1400. However, Maori were known to be using the forested coastal Taranaki landscape from at least AD 1300 to hunt the now extinct moa, and to collect shellfish, but neither of these activities necessarily required forest clearance or permanent settlement. Preserved rat-gnawed seeds in the wetland deposits provide evidence for the presence of the introduced kiore (Polynesian rat, Rattus exulans) in coastal Taranaki from about AD 1200, significantly before forest clearance or permanent human settlement. Although kiore were present in the coastal forests for as much as 400 years before forest clearance, the pollen records do not show any changes in forest composition during this time. (author). 58 refs., 4 figs., 5 tabs

Coastal Marsh Longevity, Ecological Succession, and Organic Carbon Dynamics During Early Holocene Sea-Level Rise

Science.gov (United States)

Vetter, L.; Schreiner, K. M.; Rosenheim, B. E.; Tornqvist, T. E.

2016-02-01

Coastal marsh environments perform essential ecosystem services, including nutrient filtering, soil organic matter storage, and storm surge abatement, yet much is still unknown about their formation and fate under periods of sea-level change. During the early Holocene (7-10 ka), rapid sea-level rise in coastal Louisiana was one of the primary controls over marsh development and longevity. Here, we investigate plant community composition and succession and soil organic matter storage in early Holocene coastal marshes in Louisiana using bulk elemental ratios, lignin phenol biomarkers and stable isotopes from peat layers. Sediment cores were collected in southeastern Louisiana and contain a record of an early Holocene transgressive sea-level sequence 16-25 m below present sea-level. The sedimentary record consists of an immature paleosol overlain by basal peat that accumulated in an estuarine marsh, overlain by marine lagoonal muds. A re-established marsh peat is present 1-4 m above the initial transition to marine conditions, indicating a sequence of marsh development, sea-level rise and onset of marine conditions, and then further marsh development as the rate of relative sea-level rise decelerated. Plant community composition in coastal marshes was determined through cupric oxide oxidation and lignin-phenol and non-lignin-phenol biomarker abundances. The degradation state of soil organic matter and the specific source of stabilized organic matter within the sedimentary peats were determined through lignin-phenol biomarker ratios. Organic matter sources ranged from terrestrial to marine over the course of sea-level rise, and different sites showed different amounts of marine organic matter influence and different levels of terrestrial organic matter degradation. These results have important implications for reconstructing the response of coastal marshes and their plant communities to accelerated rates of sea-level rise projected through 2100.

AIRBORNE HYPERSPECTRAL IDENTIFICATION OF INVASIVE AND OPPORTUNISTIC WETLANDS PLANT SPECIES

Science.gov (United States)

Coastal wetlands are among the most fragmented and disturbed ecosystems and the Great Lakes are no exception. One possible result is the observed increase in the presence and dominance of invasive and other opportunistic plant species, such as the common reed (Phragmites australi...

Coastal Risk Management in a Changing Climate

DEFF Research Database (Denmark)

Existing coastal management and defense approaches are not well suited to meet the challenges of climate change and related uncertanities. Professionals in this field need a more dynamic, systematic and multidisciplinary approach. Written by an international group of experts, "Coastal Risk...... Management in a Changing Climate" provides innovative, multidisciplinary best practices for mitigating the effects of climate change on coastal structures. Based on the Theseus program, the book includes eight study sites across Europe, with specific attention to the most vulnerable coastal environments...... such as deltas, estuaries and wetlands, where many large cities and industrial areas are located. Integrated risk assessment tools for considering the effects of climate change and related uncertainties. Presents latest insights on coastal engineering defenses. Provides integrated guidelines for setting up...

Bat Response To Carolina Bays and Wetland Restoration in the Southeastern U.S. Coastal Plain

Science.gov (United States)

Jennifer M. Menzel; Michael A. Menzel; John C. Kilgo; W. Mark Ford; John W. Edwards

2005-01-01

Bat activity in the southeastern United States is concentrated over riparian areas and wetland habitats. The restoration and creation of wetlands for mitigation purposes is becoming common in the Southeast. Understanding the effects of these restoration efforts on wetland flora and fauna is thus becoming increasingly important. Because bats (Order: Chiroptera) consist...

Understanding Coastal Carbon Cycling by Linking Top-Down and Bottom-Up Approaches

Science.gov (United States)

Barr, Jordan G.; Troxler, Tiffany G.; Najjar, Raymond G.

2014-09-01

The coastal zone, despite occupying a small fraction of the Earth's surface area, is an important component of the global carbon (C) cycle. Coastal wetlands, including mangrove forests, tidal marshes, and seagrass meadows, compose a domain of large reservoirs of biomass and soil C [Fourqurean et al., 2012; Donato et al., 2011; Pendleton et al., 2012; Regnier et al., 2013; Bauer et al., 2013]. These wetlands and their associated C reservoirs (2 to 25 petagrams C; best estimate of 7 petagrams C [Pendleton et al., 2012]) provide numerous ecosystem services and serve as key links between land and ocean.

Evaluating Satellite and Supercomputing Technologies for Improved Coastal Ecosystem Assessments

Science.gov (United States)

McCarthy, Matthew James

Water quality and wetlands represent two vital elements of a healthy coastal ecosystem. Both experienced substantial declines in the U.S. during the 20th century. Overall coastal wetland cover decreased over 50% in the 20th century due to coastal development and water pollution. Management and legislative efforts have successfully addressed some of the problems and threats, but recent research indicates that the diffuse impacts of climate change and non-point source pollution may be the primary drivers of current and future water-quality and wetland stress. In order to respond to these pervasive threats, traditional management approaches need to adopt modern technological tools for more synoptic, frequent and fine-scale monitoring and assessment. In this dissertation, I explored some of the applications possible with new, commercial satellite imagery to better assess the status of coastal ecosystems. Large-scale land-cover change influences the quality of adjacent coastal water. Satellite imagery has been used to derive land-cover maps since the 1960's. It provides multiple data points with which to evaluate the effects of land-cover change on water quality. The objective of the first chapter of this research was to determine how 40 years of land-cover change in the Tampa Bay watershed (6,500 km2) may have affected turbidity and chlorophyll concentration - two proxies for coastal water quality. Land cover classes were evaluated along with precipitation and wind stress as explanatory variables. Results varied between analyses for the entire estuary and those of segments within the bay. Changes in developed land percent cover best explained the turbidity and chlorophyll-concentration time series for the entire bay (R2 > 0.75, p Ocean-color satellite imagery was used to derive proxies for coastal water with near-daily satellite observations since 2000. The goal of chapter two was to identify drivers of turbidity variability for 11 National Estuary Program water bodies

Louisiana Coastal Marsh Vegetative Type, Geographic NAD83, LDWF (2001) [marsh_veg_type_pts_LDWF_2001

Data.gov (United States)

Louisiana Geographic Information Center — This data set contains vector point information. The orignal data set was collected through visual field observation by Greg Linscombe of LDWF and Robert H. Chabreck...

Observation of Wetland Dynamics with Global Navigation Satellite Signals Reflectometry

Science.gov (United States)

Zuffada, C.; Shah, R.; Nghiem, S. V.; Cardellach, E.; Chew, C. C.

2015-12-01

Wetland dynamics is crucial to changes in both atmospheric methane and terrestrial water storage. The Intergovernmental Panel on Climate Change's Fifth Assessment Report (IPCC AR5) highlights the role of wetlands as a key driver of methane (CH4) emission, which is more than one order of magnitude stronger than carbon dioxide as a greenhouse gas in the centennial time scale. Among the multitude of methane emission sources (hydrates, livestock, rice cultivation, freshwaters, landfills and waste, fossil fuels, biomass burning, termites, geological sources, and soil oxidation), wetlands constitute the largest contributor with the widest uncertainty range of 177-284 Tg(CH4) yr-1 according to the IPCC estimate. Wetlands are highly susceptible to climate change that might lead to wetland collapse. Such wetland destruction would decrease the terrestrial water storage capacity and thus contribute to sea level rise, consequently exacerbating coastal flooding problems. For both methane change and water storage change, wetland dynamics is a crucial factor with the largest uncertainty. Nevertheless, a complete and consistent map of global wetlands still needs to be obtained as the Ramsar Convention calls for a wetlands inventory and impact assessment. We develop a new method for observations of wetland change using Global Navigation Satellite Signals Reflectometry (GNSS-R) signatures for global wetland mapping in synergy with the existing capability, not only as a static inventory but also as a temporal dataset, to advance the capability for monitoring the dynamics of wetland extent relevant to addressing the science issues of CH4 emission change and terrestrial water storage change. We will demonstrate the capability of the new GNSS-R method over a rice field in the Ebro Delta wetland in Spain.

Louisiana Speaks Regional Vision Transit Corridors, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_vision_transit_corridors

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates the primary and secondary transit corridors included in the Louisiana Speaks Regional Plan Vision. This network accommodates a...

Towards a macrosystems approach for successful coastal management

Science.gov (United States)

Managing coastal resources for resiliency and sustainability often requires integrative, multi-disciplinary approaches across varying spatial and temporal scales to engage stakeholders and inform decision-makers. We discuss case studies integrating wetland ecology, economics, soc...

HYDROGEOMORPHIC INFLUENCES ON MACROPHYTES AS HABITAT IN GREAT LAKES WETLANDS

Science.gov (United States)

We used rapid survey techniques to map saubmergerd, floating and emergent vegetation in 10 coastal wetlands of Lake Superior. Density and structure of plant beds in "bay," "main channel," and "side channel" areas was evaluated from cover indices and presence/dominance by growth f...

Mid term monitoring of heavy metals content in soils of Mediterranean coastal wetlands. La Albufera de Valencia Natural Park, Spain

Science.gov (United States)

Pascual-Aguilar, Juan Antonio; Andreu, Vicente; Gimeno-García, Eugenia

2014-05-01

Coastal wetlands, in general, and Mediterranean ones, in particular, suffer from differente anthropogenic pressures that may affect their intrinsic environmental and ecological functions. Most, if not all, Mediterranean wetlands are not natural spaces were preservation of habitat and wildlife is the only management policy achieved, bur rather their terriroty is a combination of land units with different activities and influences, such as farming, environmental protection and connectivities with urban and industrial areas. Therefore, the need of periodical monitoring is required whenever pressures and environmental health of wetlands is assessed, particularly of those processes that affect the interconnection of environmental compartiments involving water, soils and biota. In agro-ecological protected wetlands soils play and important role because they are potential sources of pollutants due to farming practices. In this case, presence of heavy metals in soils is and indicator of both environmental health and anthtopogenic direct (farming activities) and indirect (neighbour urban areas) pressures. In this work a mid term (17 year) monitoring of seven heavy metals (Cd, Co, Cr, Cu, Pb, Ni and Zn) in soils of coastal Mediterranean wetlands (La Albufera Natural Park, Spain) are analyzed. Two monitoring campaings were achieved in 1991 and 2008. In both cases the same 20 points were visited which were distributed in the natural park according two four different sectors of potential anthropogenic pressure and land use. At each point two soil samples were collected at differente depths (0 to 20 cm and 20 to 40 cm). The selected metals were analyzed to determine its total and extractable fractions by treatment with EDTA. Atomic Absorption Spectrometry, using graphite furnace when necessary, was used for the determination of metals. In general, there is a reduction of metal contents in the study area in both dates. The trend of metals according to average concentration (mg

Coastal Sea Level and Estuary Tide Modeling in Bangladesh Using SAR, Radar and GNSS-R Altimetry

Science.gov (United States)

Jia, Y.; Shum, C. K.; Sun, J.; Li, D.; Shang, K.; Yi, Y.; Calmant, S.; Ballu, V.; Chu, P.; Johnson, J.; Park, J.; Bao, L.; Kuo, C. Y.; Wickert, J.

2017-12-01

Bangladesh, located at the confluence of three large rivers - Ganges, Brahmaputra and Meghna, is a low-lying country. It is prone to monsoonal flooding, potentially aggravated by more frequent and intensified cyclones resulting from anthropogenic climate change. Its coastal estuaries, the Sundarbans wetlands, have the largest Mangrove forest in the world, and exhibits complex tidal dynamics. In order to study flood hazards, ecological or climate changes over floodplains, it is fundamentally important to know the water level and water storage capacity in wetlands. Inaccurate or inadequate information about wetland water storage will cause significant errors in hydrological simulation and modeling for understanding ecological and economic implications. However, in most areas, the exact knowledge of water level change and the flow patterns is lacking due to insufficient monitoring of water level gauging stations on private and public lands within wetlands or floodplains, due to the difficulty of physical access to the sites and logistics in data gathering. Usage of satellite all-weather remote sensing products provides an alternative approach for monitoring the water level variation over floodplains or wetlands. In this study, we used a combination of observations from satellite radar altimetry (Envisat/Jason-2/Altika/Sentinel-3), L-band synthetic aperture radar (ALOS-1/-2) backscattering coefficients inferred water level, GNSS-R altimetry from two coastal/river GNSS sites, for measuring coastal and estuary sea-level and conducting estuary ocean tide modeling in the Bangladesh delta including the Sundarbans wetlands.

Design of a semi-autonomous boat for measurements of coastal sedimentation and erosion

Directory of Open Access Journals (Sweden)

D. Smith

2015-03-01

Full Text Available Measurement of sediment deposition and erosion in coastal areas is a challenge due to soft shifting sediments, but is critical to assessing loss or restoration of coastal sediments and wetlands. The aim of this project was to design and construct a semi-autonomous boat with water depth measuring capabilities. It was intended to map the depth of coastal wetlands to determine erosion rates and assess coastal restoration effects. Depth-measuring equipment was incorporated into an autonomous pontoon boat powered by solar panels. The propulsion system consisted of two paddlewheels and two-way motors to allow movement and positioning for measurements. Modifications included a lightweight, hard coating on the pontoons and powder-coating the frame to extend their usable life. A microcontroller controlled the boat and captured depth data from sensors and location data with a GPS system. The depth measuring system consisted of a pulley and counter system that completed each measurement in less than 45 seconds. This allowed the boat to take approximately 400 measurements per day. Net accuracy was approximately 3 cm in the tested configuration. The boat can continually measure the depth of specified areas in the wetlands; with this data, the change in depth can be monitored to see the effects of restoration projects.

Louisiana Speaks Regional Plan Vision Reinvestment Centers, UTM Zone 15N NAD83, Louisiana Recovery Authority (2007), [louisiana_speaks_vision_reinvestment_centers

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates reinvestment centers included in the Louisiana Speaks Regional Plan Vision. Reinvestment centers highlight communities that...

Resilience from coastal protection.

Science.gov (United States)

Ewing, Lesley C

2015-10-28

Coastal areas are important residential, commercial and industrial areas; but coastal hazards can pose significant threats to these areas. Shoreline/coastal protection elements, both built structures such as breakwaters, seawalls and revetments, as well as natural features such as beaches, reefs and wetlands, are regular features of a coastal community and are important for community safety and development. These protection structures provide a range of resilience to coastal communities. During and after disasters, they help to minimize damages and support recovery; during non-disaster times, the values from shoreline elements shift from the narrow focus on protection. Most coastal communities have limited land and resources and few can dedicate scarce resources solely for protection. Values from shore protection can and should expand to include environmental, economic and social/cultural values. This paper discusses the key aspects of shoreline protection that influence effective community resilience and protection from disasters. This paper also presents ways that the economic, environmental and social/cultural values of shore protection can be evaluated and quantified. It presents the Coastal Community Hazard Protection Resilience (CCHPR) Index for evaluating the resilience capacity to coastal communities from various protection schemes and demonstrates the use of this Index for an urban beach in San Francisco, CA, USA. © 2015 The Author(s).

Component greenhouse gas fluxes and radiative balance from two deltaic marshes in Louisiana: Pairing chamber techniques and eddy covariance

Science.gov (United States)

Krauss, Ken W.; Holm, Guerry O.; Perez, Brian C.; McWhorter, David E.; Cormier, Nicole; Moss, Rebecca; Johnson, Darren; Neubauer, Scott C; Raynie, Richard C

2016-01-01

Coastal marshes take up atmospheric CO2 while emitting CO2, CH4, and N2O. This ability to sequester carbon (C) is much greater for wetlands on a per-area basis than from most ecosystems, facilitating scientific, political, and economic interest in their value as greenhouse gas sinks. However, the greenhouse gas balance of Gulf of Mexico wetlands is particularly understudied. We describe the net ecosystem exchange (NEEc) of CO2 and CH4 using eddy covariance (EC) in comparison with fluxes of CO2, CH4, and N2O using chambers from brackish and freshwater marshes in Louisiana, USA. From EC, we found that 182 g C m-2 y-1 was lost through NEEc from the brackish marsh. Of this, 11 g C m-2 y-1 resulted from net CH4 emissions and the remaining 171 g C m-2 y-1 resulted from net CO2 emissions. In contrast, -290 g C m2 y-1 was taken up through NEEc by the freshwater marsh, with 47 g C m-2 y-1 emitted as CH4 and -337 g C m-2 y-1 taken up as CO2. From chambers, we discovered that neither site had large fluxes of N2O. Sustained-flux greenhouse gas accounting metrics indicated that both marshes had a positive (warming) radiative balance, with the brackish marsh having a substantially greater warming effect than the freshwater marsh. That net respiratory emissions of CO2 and CH4 as estimated through chamber techniques were 2-4 times different from emissions estimated through EC requires additional understanding of the artifacts created by different spatial and temporal sampling footprints between techniques.

Seasonality and flux estimates of dissolved organic carbon in tidal wetlands and estuaries in the U.S. Mid- Atlantic Bight and Gulf of Mexico from ocean color

Science.gov (United States)

Cao, F.; Tzortziou, M.; Hu, C.; Najjar, R.

2016-02-01

Tidal wetlands and estuaries are dynamic features of coastal ocean and play critical roles in the global carbon cycle. Exchanges of dissolved organic carbon (DOC) between tidal wetlands and adjacent estuaries have important implications for carbon sequestration in tidal wetlands as well as biogeochemical cycling of wetlands derived material in the coastal zones. Recent studies demonstrated that the absorption coefficients of chromophoric dissolved organic matter at λ= 275 and 295 nm, which can be derived from satellite ocean color observations, can be used to accurately retrieve dissolved organic carbon (DOC) in some coastal waters. Based on a synthesis of existing field observations collected covering wide spatial and temporal variability in the Mid-Atlantic Bight and the Gulf of Mexico, here we developed and validated new empirical models to estimate coastal DOC from remotely sensed bio-optical properties of the surface water. We focused on the interfaces between tidal wetland-estuary and estuary-shelf water domains. The DOC algorithms were applied to SeaWiFs and MODIS observations to generate long-term climatological DOC distributions from 1998 to 2014. Empirical orthogonal function analysis revealed strong seasonality and spatial gradients in the satellite retrieved DOC in the tidal wetlands and estuaries. Combined with field observations and biogeochemical models, satellite retrievals can be used to scale up carbon fluxes from individual marshes and sub-estuaries to the whole estuarine system, and improve understanding of biogeochemical exchanges between terrestrial and aquatic ecosystems.

Effects of disturbance associated with seismic exploration for oil and gas reserves in coastal marshes

Science.gov (United States)

Howard, Rebecca J.; Wells, Christopher J.; Michot, Thomas C.; Johnson, Darren J.

2014-01-01

Anthropogenic disturbances in wetland ecosystems can alter the composition and structure of plant assemblages and affect system functions. Extensive oil and gas extraction has occurred in wetland habitats along the northern Gulf of Mexico coast since the early 1900s. Activities involved with three-dimensional (3D) seismic exploration for these resources cause various disturbances to vegetation and soils. We documented the impact of a 3D seismic survey in coastal marshes in Louisiana, USA, along transects established before exploration began. Two semi-impounded marshes dominated by Spartina patens were in the area surveyed. Vegetation, soil, and water physicochemical data were collected before the survey, about 6 weeks following its completion, and every 3 months thereafter for 2 years. Soil cores for seed bank emergence experiments were also collected. Maximum vegetation height at impact sites was reduced in both marshes 6 weeks following the survey. In one marsh, total vegetation cover was also reduced, and dead vegetation cover increased, at impact sites 6 weeks after the survey. These effects, however, did not persist 3 months later. No effects on soil or water properties were identified. The total number of seeds that germinated during greenhouse studies increased at impact sites 5 months following the survey in both marshes. Although some seed bank effects persisted 1 year, these effects were not reflected in standing vegetation. The marshes studied were therefore resilient to the impacts resulting from 3D seismic exploration because vegetation responses were short term in that they could not be identified a few months following survey completion.

Effects of Disturbance Associated With Seismic Exploration for Oil and Gas Reserves in Coastal Marshes

Science.gov (United States)

Howard, Rebecca J.; Wells, Christopher J.; Michot, Thomas C.; Johnson, Darren J.

2014-07-01

Anthropogenic disturbances in wetland ecosystems can alter the composition and structure of plant assemblages and affect system functions. Extensive oil and gas extraction has occurred in wetland habitats along the northern Gulf of Mexico coast since the early 1900s. Activities involved with three-dimensional (3D) seismic exploration for these resources cause various disturbances to vegetation and soils. We documented the impact of a 3D seismic survey in coastal marshes in Louisiana, USA, along transects established before exploration began. Two semi-impounded marshes dominated by Spartina patens were in the area surveyed. Vegetation, soil, and water physicochemical data were collected before the survey, about 6 weeks following its completion, and every 3 months thereafter for 2 years. Soil cores for seed bank emergence experiments were also collected. Maximum vegetation height at impact sites was reduced in both marshes 6 weeks following the survey. In one marsh, total vegetation cover was also reduced, and dead vegetation cover increased, at impact sites 6 weeks after the survey. These effects, however, did not persist 3 months later. No effects on soil or water properties were identified. The total number of seeds that germinated during greenhouse studies increased at impact sites 5 months following the survey in both marshes. Although some seed bank effects persisted 1 year, these effects were not reflected in standing vegetation. The marshes studied were therefore resilient to the impacts resulting from 3D seismic exploration because vegetation responses were short term in that they could not be identified a few months following survey completion.

Sharing the earth: case studies on population, wildlife, and the environment.

Science.gov (United States)

Waak-strom, P

1994-01-01

In 1988 the National Audubon Society's population program began to develop a joint project on the issues of human population growth and wildlife management by comparing sites in the United States and overseas to identify actions necessary for a sustainable ecosystem. Eight US sites were matched with eight sites in other countries. The Audubon wildlife managers visited their partners' international settings and then hosted their counterparts at their own sanctuaries in the US. All sites involved water resources: three were coastal systems, two had major rivers, and three were freshwater wetlands. Coastal systems comprised Tampa Bay sanctuaries, Florida, Wat Phai Lom, Wat Asokaram, and Ban Lung Jorm, Thailand. In Thailand wildlife sanctuaries have been set aside within monastery grounds, hence Thai bird colonies are more secure than those of Rookery Bay Sanctuary, Florida and Pulau Rambut, Indonesia. An Audubon warden patrols southwest Florida's Rookery Bay, whereas in Pulau Rambut there is insufficient government staff to protect it from human disturbance. Along the Yucatan Peninsula, Louisiana's Rainey Sanctuary and Mexico's Rio Lagartos system both encompass great tracts of fertile wetlands teeming with wildlife. However, Louisiana is losing 130 square kilometers of coastal wetland a year, the most rapid loss on earth. Population growth, poverty, and unsustainable economic activities put pressure on the Sabal Palm Grove Sanctuary, Texas, and the Biotopo del Manati, Guatemala, river systems. Deforestation is a serious problem in both areas. Platte River, Nebraska, and Indus River, Pakistan. Indus River, Pakistan, still maintains much of its pristine quality, while Platte River, Nebraska, has been dammed and diverted. Freshwater Wetlands include the Corkscrew Swamp Sanctuary, Florida, Lake Nakuru, Kenya, Alkali Lake Sanctuary, North Dakota, and Estancia Caiman, Brazil. The Corkscrew area's growth is caused by migration, while Nakuru's growth is a result of migration

Louisiana 2011 Lidar Coverage, USACE National Coastal Mapping Program

Data.gov (United States)

Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Gulf of Mexico in 2011. The data types collected...

Louisiana 2010 Lidar Coverage, USACE National Coastal Mapping Program

Data.gov (United States)

Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Gulf of Mexico in 2010. The data types collected...

78 FR 69664 - Proposed Information Collection Request; Comment Request; Approval of State Coastal Nonpoint...

Science.gov (United States)

2013-11-20

... Collection Request; Comment Request; Approval of State Coastal Nonpoint Pollution Control Programs AGENCY... to submit an information collection request (ICR), ``Approval of State Coastal Nonpoint Pollution... Watershed Protection Division, Office of Wetlands Oceans and Watersheds, Mail Code 4503-T, Environmental...

Louisiana 2006 Lidar Coverage, USACE National Coastal Mapping Program

Data.gov (United States)

Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Gulf of Mexico in the summer of 2006. The data...

Louisiana 2007 Lidar Coverage, USACE National Coastal Mapping Program

Data.gov (United States)

Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) has performed a coastal survey along the Gulf of Mexico, in the summer of 2007. The data...

Limitations and potential of satellite imagery to monitor environmental response to coastal flooding

Science.gov (United States)

Ramsey, Elijah W.; Werle, Dirk; Suzuoki, Yukihiro; Rangoonwala, Amina; Lu, Zhong

2012-01-01

Storm-surge flooding and marsh response throughout the coastal wetlands of Louisiana were mapped using several types of remote sensing data collected before and after Hurricanes Gustav and Ike in 2008. These included synthetic aperture radar (SAR) data obtained from the (1) C-band advance SAR (ASAR) aboard the Environmental Satellite, (2) phased-array type L-band SAR (PALSAR) aboard the Advanced Land Observing Satellite, and (3) optical data obtained from Thematic Mapper (TM) sensor aboard the Land Satellite (Landsat). In estuarine marshes, L-band SAR and C-band ASAR provided accurate flood extent information when depths averaged at least 80 cm, but only L-band SAR provided consistent subcanopy detection when depths averaged 50 cm or less. Low performance of inundation mapping based on C-band ASAR was attributed to an apparent inundation detection limit (>30 cm deep) in tall Spartina alterniflora marshes, a possible canopy collapse of shoreline fresh marsh exposed to repeated storm-surge inundations, wind-roughened water surfaces where water levels reached marsh canopy heights, and relatively high backscatter in the near-range portion of the SAR imagery. A TM-based vegetation index of live biomass indicated that the severity of marsh dieback was linked to differences in dominant species. The severest impacts were not necessarily caused by longer inundation but rather could be caused by repeated exposure of the palustrine marsh to elevated salinity floodwaters. Differential impacts occurred in estuarine marshes. The more brackish marshes on average suffered higher impacts than the more saline marshes, particularly the nearshore coastal marshes occupied by S. alterniflora.

Floodplain and Wetland Assessment for the Mortandad Wetland Enhancement and the DP Dissipater Projects at Los Alamos National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Hathcock, Charles Dean [Los Alamos National Laboratory

2017-03-31

This floodplain and wetland assessment was prepared in accordance with 10 Code of Federal Regulations (CFR) 1022 Compliance with Floodplain and Wetland Environmental Review Requirements, which was promulgated to implement the U.S. Department of Energy (DOE) requirements under Executive Order 11988 Floodplain Management and Executive Order 11990 Wetlands Protection. According to 10 CFR 1022, a 100-year floodplain is defined as “the lowlands adjoining inland and coastal waters and relatively flat areas and flood prone areas of offshore islands” and a wetland is defined as “an area that is inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances does support, a prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs, and similar areas.” In this action, DOE is proposing two projects to improve wetland and floodplain function at Los Alamos National Laboratory (LANL). The proposed work will comply with corrective action requirements under the Settlement Agreement and Stipulated Final Compliance Order (Settlement Agreement)1 Number HWB-14-20. The first project is located in Technical Areas (TA)-03 in upper Mortandad Canyon. The upper Mortandad wetlands have existing stormwater controls that need to be rehabilitated. Head-cut formation is occurring at the downstream portion of the wetland. This project will repair damages to the wetland and reduce the future erosion potential. The second project is located in TA-21 in Delta Prime (DP) Canyon. The intent of the DP Dissipater Project in DP Canyon is to install stormwater control structures in DP Canyon to retain low channel flows and reduce downstream sediment transport as well as peak flows during low and moderate storm events. Due to increased erosion, the stream bank in this area has unstable vertical walls within the stream channel. The DOE prepared this floodplain and wetland

Comparison of Qinzhou bay wetland landscape information extraction by three methods

Directory of Open Access Journals (Sweden)

X. Chang

2014-04-01

and OO is 219 km2, 193.70 km2, 217.40 km2 respectively. The result indicates that SC is in the f irst place, followed by OO approach, and the third DT method when used to extract Qingzhou Bay coastal wetland.

Assessment of marine debris on the coastal wetland of Martil in the North-East of Morocco.

Science.gov (United States)

Alshawafi, Adel; Analla, Mohamed; Alwashali, Ebrahim; Aksissou, Mustapha

2017-04-15

Plastic waste at the coastal wetland in Martil beach in the North-East of Morocco is one of the problems that have appeared recently. This study aims to characterize the marine debris in the coast of Martil during the year 2015. The sampling is seasonally by type and size. The result shows, for the macro debris, the abundance of plastic (57%), lumber and paper (21.93%), cloth and fabric (7.8%), glass (5.42%), metal (4.40%), and rubber (3.4%). Micro debris is also present in the area in several forms such as wood, plants, and others by 75,63%. This was followed by the foam (26,95%), line (7,8%), and the film (1,23%). The seasonal variation (S1: January-March and S3: July to September) are the most polluted months of the year. The sources of marine debris are mainly tourism (beach users), land (run off), and commercial fishing in the four seasons of the year. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ecological health status of the Lagos wetland ecosystems: Implications for coastal risk reduction

Science.gov (United States)

Agboola, Julius I.; Ndimele, Prince E.; Odunuga, Shakirudeen; Akanni, Adeniran; Kosemani, Bosede; Ahove, Michael A.

2016-12-01

Lagos, a major urban agglomeration in the world is characterized by wetlands and basin for upstream rivers such as Ogun, Oshun and Yewa Rivers. Ongoing environmental pressures exerted by large-scale land reclamation for residential quarters, refuse and sewage dumping, and other uses, however, are suspected to have had a substantial impact on ecological health of the Lagos wetland ecosystems over the last few decades. To determine the impact of these pressures, we examined spatial changes in three wetlands areas- Badore/Langbasa (BL), Festac/Iba/Ijegun (FI) and Ologe/Otto-Awori (OO) through field sample collection and analyses of surface water, sediments, air-water interface gas fluxes and vegetations. Surface water conductivity, total suspended solids (TSS), alkalinity, chloride, biological oxygen demand (BOD), nitrate, phosphate and heavy metals (Zn, Cu, Fe, Na, Mn, Pb, Cd, K and Ni) exhibited relative spatial stability while other water quality parameters varied significantly (P International Union for Conservation of Nature (IUCN). There are indications of steady rise in greenhouse gas levels in Lagos since air CO2 value at BL have reached global threshold of 400 ppm with OO and FI closely approaching. We conclude that the Lagos wetland ecosystems, especially OO and FI still have some semblance of natural habitat. However, further destruction and unwise use of the resources could cause damage to physical, chemical, geological and biological processes in nature, which could result to grave socio-economic and cultural consequences to the local communities whose livelihood and lifestyle depend on these valued wetlands.

Patterns and drivers for wetland connections in the Prairie Pothole Region, United States

Science.gov (United States)

Vanderhoof, Melanie; Christensen, Jay R.; Alexander, Laurie C.

2017-01-01

Ecosystem function in rivers, lakes and coastal waters depends on the functioning of upstream aquatic ecosystems, necessitating an improved understanding of watershed-scale interactions including variable surface-water flows between wetlands and streams. As surface water in the Prairie Pothole Region expands in wet years, surface-water connections occur between many depressional wetlands and streams. Minimal research has explored the spatial patterns and drivers for the abundance of these connections, despite their potential to inform resource management and regulatory programs including the U.S. Clean Water Act. In this study, wetlands were identified that did not intersect the stream network, but were shown with Landsat images (1990–2011) to become merged with the stream network as surface water expanded. Wetlands were found to spill into or consolidate with other wetlands within both small (2–10 wetlands) and large (>100 wetlands) wetland clusters, eventually intersecting a stream channel, most often via a riparian wetland. These surface-water connections occurred over a wide range of wetland distances from streams (averaging 90–1400 m in different ecoregions). Differences in the spatial abundance of wetlands that show a variable surface-water connection to a stream were best explained by smaller wetland-to-wetland distances, greater wetland abundance, and maximum surface-water extent. This analysis demonstrated that wetland arrangement and surface water expansion are important mechanisms for depressional wetlands to connect to streams and provides a first step to understanding the frequency and abundance of these surface-water connections across the Prairie Pothole Region.

Geopressured-geothermal well activities in Louisiana

International Nuclear Information System (INIS)

John, C.J.

1992-10-01

Since September 1978, microseismic networks have operated continuously around US Department of Energy (DOE) geopressured-geothermal well sites to monitor any microearthquake activity in the well vicinity. Microseismic monitoring is necessary before flow testing at a well site to establish the level of local background seismicity. Once flow testing has begun, well development may affect ground elevations and/or may activate growth faults, which are characteristic of the coastal region of southern Louisiana and southeastern Texas where these geopressured-geothermal wells are located. The microseismic networks are designed to detest small-scale local earthquakes indicative of such fault activation. Even after flow testing has ceased, monitoring continues to assess any microearthquake activity delayed by the time dependence of stress migration within the earth. Current monitoring shows no microseismicity in the geopressured-geothermal prospect areas before, during, or after flow testing

Fish utilisation of wetland nurseries with complex hydrological connectivity.

Directory of Open Access Journals (Sweden)

Ben Davis

Full Text Available The physical and faunal characteristics of coastal wetlands are driven by dynamics of hydrological connectivity to adjacent habitats. Wetlands on estuary floodplains are particularly dynamic, driven by a complex interplay of tidal marine connections and seasonal freshwater flooding, often with unknown consequences for fish using these habitats. To understand the patterns and subsequent processes driving fish assemblage structure in such wetlands, we examined the nature and diversity of temporal utilisation patterns at a species or genus level over three annual cycles in a tropical Australian estuarine wetland system. Four general patterns of utilisation were apparent based on CPUE and size-structure dynamics: (i classic nursery utlisation (use by recently settled recruits for their first year (ii interrupted peristence (iii delayed recruitment (iv facultative wetland residence. Despite the small self-recruiting 'facultative wetland resident' group, wetland occupancy seems largely driven by connectivity to the subtidal estuary channel. Variable connection regimes (i.e. frequency and timing of connections within and between different wetland units (e.g. individual pools, lagoons, swamps will therefore interact with the diversity of species recruitment schedules to generate variable wetland assemblages in time and space. In addition, the assemblage structure is heavily modified by freshwater flow, through simultaneously curtailing persistence of the 'interrupted persistence' group, establishing connectivity for freshwater spawned members of both the 'facultative wetland resident' and 'delayed recruitment group', and apparently mediating use of intermediate nursery habitats for marine-spawned members of the 'delayed recruitment' group. The diversity of utilisation pattern and the complexity of associated drivers means assemblage compositions, and therefore ecosystem functioning, is likely to vary among years depending on variations in hydrological

Bat response to carolina bays and wetland restoration in the southeastern U.S. Coastal Plain.

Energy Technology Data Exchange (ETDEWEB)

Menzel, Jennifer M.; Michael A. Menzel; John C. Kilgo; W. Mark Ford; ; John W. Edwards.

2005-09-01

Abstract: Bat activity in the southeastern United States is concentrated over riparian areas and wetland habitats. The restoration and creation of wetlands for mitigation purposes is becoming common in the Southeast. Understanding the effects of these restoration efforts on wetland flora and fauna is thus becoming increasingly important. Because bats (Order: Chiroptera) consist of many species that are of conservation concern and are commonly associated with wetland and riparian habitats in the Southeast (making them a good general indicator for the condition of wetland habitats), we monitored bat activity over restored and reference Carolina bays surrounded by pine savanna (Pinus spp.) or mixed pine-hardwood habitat types at the Savannah River Site in South Carolina. In order to determine how wetland restoration efforts affected the bat community, we monitored bat activity above drained Carolina bays pre- and post-restoration. Our results indicate that bat activity was greater over reference (i.e., undrained) than drained bays prior to the restorative efforts. One year following combined hydrologic and vegetation treatment, however, bat activity was generally greater over restored than reference bays. Bat activity was also greater over both reference and restored bays than in random, forested interior locations. We found significantly more bat activity after restoration than prior to restoration for all but one species in the treatment bays, suggesting that Carolina bay restoration can have almost immediate positive impacts on bat activity.

Louisiana Coastal Marsh Vegetative Type (poly), Geographic NAD83, LDWF (2001) [marsh_veg_type_poly_LDWF_2001

Data.gov (United States)

Louisiana Geographic Information Center — This data set contains vector line information. The original data set was collected through visual field observation by Greg Linscombe of LDWF and Robert H. Chabreck...

Adaptation to Sea Level Rise in Coastal Units of the National Park Service (Invited)

Science.gov (United States)

Beavers, R. L.

2010-12-01

83 National Park Service (NPS) units contain nearly 12,000 miles of coastal, estuarine and Great Lakes shoreline and their associated resources. Iconic natural features exist along active shorelines in NPS units, including, e.g., Cape Cod, Padre Island, Hawaii Volcanoes, and the Everglades. Iconic cultural resources managed by NPS include the Cape Hatteras Lighthouse, Fort Sumter, the Golden Gate, and heiaus and fish traps along the coast of Hawaii. Impacts anticipated from sea level rise include inundation and flooding of beaches and low lying marshes, shoreline erosion of coastal areas, and saltwater intrusion into the water table. These impacts and other coastal hazards will threaten park beaches, marshes, and other resources and values; alter the viability of coastal roads; and require the NPS to re-evaluate the financial, safety, and environmental implications of maintaining current projects and implementing future projects in ocean and coastal parks in the context of sea level rise. Coastal erosion will increase as sea levels rise. Barrier islands along the coast of Louisiana and North Carolina may have already passed the threshold for maintaining island integrity in any scenario of sea level rise (U.S. Climate Change Science Program Synthesis and Assessment Program Report 4.1). Consequently, sea level rise is expected to hasten the disappearance of historic coastal villages, coastal wetlands, forests, and beaches, and threaten coastal roads, homes, and businesses. While sea level is rising in most coastal parks, some parks are experiencing lower water levels due to isostatic rebound and lower lake levels. NPS funded a Coastal Vulnerability Project to evaluate the physical and geologic factors affecting 25 coastal parks. The USGS Open File Reports for each park are available at http://woodshole.er.usgs.gov/project-pages/. These reports were designed to inform park planning efforts. NPS conducted a Storm Vulnerability Project to provide ocean and coastal

Louisiana Speaks Regional Plan Vision Special Economic Zones, UTM Zone 15N NAD83, Louisiana Recovery Authority (2007), [louisiana_speaks_vision_special_economic_zones

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates special economic zones included in the Louisiana Speaks Regional Plan Vision. Special economic zones include existing national,...

Louisiana Speaks Transportation Option C Transit Stations, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_c_transit_stations

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates potential fixed-transit stations included in the Louisiana Speaks Regional Plan community growth option of compact development...

A multigear protocol for sampling crayfish assemblages in Gulf of Mexico coastal streams

Science.gov (United States)

William R. Budnick; William E. Kelso; Susan B. Adams; Michael D. Kaller

2018-01-01

Identifying an effective protocol for sampling crayfish in streams that vary in habitat and physical/chemical characteristics has proven problematic. We evaluated an active, combined-gear (backpack electrofishing and dipnetting) sampling protocol in 20 Coastal Plain streams in Louisiana. Using generalized linear models and rarefaction curves, we evaluated environmental...

Intraspecific variation in growth of marsh macrophytes in response to salinity and soil type: Implications for wetland restoration

Science.gov (United States)

Howard, R.J.

2010-01-01

Genetic diversity within plant populations can influence plant community structure along environmental gradients. In wetland habitats, salinity and soil type are factors that can vary along gradients and therefore affect plant growth. To test for intraspecific growth variation in response to these factors, a greenhouse study was conducted using common plants that occur in northern Gulf of Mexico brackish and salt marshes. Individual plants of Distichlis spicata, Phragmites australis, Schoenoplectus californicus, and Schoenoplectus robustus were collected from several locations along the coast in Louisiana, USA. Plant identity, based on collection location, was used as a measure of intraspecific variability. Prepared soil mixtures were organic, silt, or clay, and salinity treatments were 0 or 18 psu. Significant intraspecific variation in stem number, total stem height, or biomass was found in all species. Within species, response to soil type varied, but increased salinity significantly decreased growth in all individuals. Findings indicate that inclusion of multiple genets within species is an important consideration for marsh restoration projects that include vegetation plantings. This strategy will facilitate establishment of plant communities that have the flexibility to adapt to changing environmental conditions and, therefore, are capable of persisting over time. ?? Coastal and Estuarine Research Federation 2009.

Louisiana Speaks Transportation Option B Transit Corridors, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_b_transit_corridors

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional, subregional, and local transit corridors included in the Louisiana Speaks Regional Plan community growth option of...

Louisiana Speaks Transportation Option B Roadway Improvements, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_b_roadway_improvements

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional roadways included in the Louisiana Speaks community growth option of compact and dispersed development (Option B)....

Louisiana Speaks Transportation Option C Roadway Improvements, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_c_roadway_improvements

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional roadways included in the Louisiana Speaks community growth option of compact development (Option C). This network...

Louisiana Speaks Transportation Option C Transit Corridors, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_c_transit_corridors

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional, subregional, and local transit corridors included in the Louisiana Speaks Regional Plan community growth option of...

Louisiana Speaks Transportation Option B Transit Stations, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_b_transit_stations

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates potential fixed-transit stations included in the Louisiana Speaks Regional Plan community growth option of compact and dispersed...

Louisiana Speaks Transportation Option A Roadway Improvements, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_a_roadway_improvements

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional roadways included in the Louisiana Speaks Regional Plan community growth option of dispersed development (Option A)....

Louisiana Speaks Regional Plan Vision New Growth Areas, UTM Zone 15N NAD83, Louisiana Recovery Authority (2007), [louisiana_speaks_vision_new_growth_areas

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates new growth areas included in the Louisiana Speaks Regional Plan Vision. New growth areas include a mix of industrial, single...

Louisiana Speaks Regional Plan Vision New or Improved Roadways, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_vision_roadway_improvements