The effect of salinity on utilization of shallow-water nursery habitats by aquatic fauna was assessed in San Antonio Bay, Texas. Overall, 272 samples were collected in a variety of marsh, vegetated, and non-vegetated habitats throughout the Bay system. Sampling began in fall 1986 and extended through fall 1989. Vegetated habitats, marsh, and submerged aquatic vegetation has significantly higher densities of fishes and decapod crustaceans than bare mud habitats.

Salt marsh habitats along the shoreline of Halls Lake are threatened by wave erosion, but the reconstruction of barrier islands to reduce this erosion will modify or destroy nonvegetated habitats in West Bay. Twenty-four 1.8-m diameter drop samples were taken in and around Halls Lake in West Galveston Bay during May, 1990 on daylight flood tides to provide information on the relative value of estuarine habitats for fishery species. Over 3,000 fish, shrimp, and crabs were collected from about 39 taxa. In conjunction with other published data on habitat value in Galveston Bay, our results indicate that for most crustacean, the Halls Lake marshes are more valuable than the other habitats examined. The relative value of the habitats for fishes was highly species-dependent. A survey of the West Bay shoreline indicated that valuable salt marsh habitats could be established on created barrier islands if direction of exposure and shoreline slope were controlled.

Terracing uses existing bottom sediments to form terraces or ridges at marsh elevation and the intertidal zone is planted with marsh vegetation. This study examined the habitat value of terracing at Sabine National Wildlife Refuge, Louisiana in the spring and fall of 1999 by quantifying and comparing nekton densities in a 9-yr old terrace field and nearby reference area using a 1 m2 drop sampler. Using density and biomass patterns and the percentage of marsh and pond area in the terrace field, we concluded that terrace fields support higher standing crops of most fishery species compared with shallow marsh ponds of similar size. Future restoration projects could include design changes to increase the proportion of marsh in a terrace field and enhance the habitat value of marsh terraces for fishery species.

During July and October 1988, a total of 42 samples were collected in salt marsh habitats of the Caminada Bay system near Grand Isle, Louisiana to evaluate the use of the marsh surface by aquatic fauna on flood tide. Differences in animal densities between the marsh surface and nonvegetated marsh edge were compared and evaluated.

Between May 5, 1993 and September 19, 1994, we collected quantitative 1-m2 area drop samples and measured a variety of habitat attributes using field surveys and aerial photography to characterize three existing marshes (Atkinson Island, Hog Island, and Cedar Point) in Galveston Bay. We also compared nekton densities among different types of intertidal and shallow subtidal habitats (pond, channel, cove, open bay, and four marsh types). The vegetated surface consistently contained more species and dominant species exhibited at least some degree of habitat selection. To maximize fishery habitat, we recommend placing greater emphasis on constructing low marsh edge habitat by creating large areas of Spartina alterniflora and Scirpus maritimus marsh interspersed with a dense network of shallow channels and interconnected ponds.

Sampled marshes and ponds along two transects within the intermediate and brackish marsh zones of Breton Sound, Louisiana, from May 7-11, 2001. Sampling followed several planned releases of freshwater from the Caernarvon diversion structure during the winter of 2000 and spring of 2001 as part of a larger study to examine the ecological effect of pulsed freshwater releases on the ecosystem.

Measured fine-scale distributions of nekton on the vegetated marsh surface using drop samplers and utilized these patterns to estimate population size. Natant decapod crustaceans were most abundant in the marsh, while densities of juvenile brown shrimp, white shrimp, and blue crabs were highest 1-m from the marsh edge interface, declining rapidly towards open water. Developed regression models to describe fine-scale density patterns and used this information to estimate the population of natant decapods in a highly fragmented marsh in the Galveston Bay system.

PURPOSE: The research survey provides a fisheries-independent source of information about all marine living organisms that are captured by the fishing trawl used to obtain samples in the southern Gulf of St. Lawrence. DESCRIPTION: Tow, catch, length frequency, and biological information for fish caught during the annual September research vessel trawl surveys in the southern Gulf of St. Lawrence (NAFO Division 4T). Abundance indices and spatial distribution patterns of commercial and non-commercial groundfish. The catch data that appear in this dataset SHOULD NOT BE USED FOR ECOLOGICAL ANALYSES INVOLVING CATCH RATES. Important factors such as vessel, fishing gear and diurnal periods must be accounted for to use these data in analyses. Please contact the data custodians if you are interested in using this data for any kind of ecological analyses involving catch rates. PARAMETERS COLLECTED: abundance estimates (ecological); distribution (ecological); species counts (ecological); gear (fishing); vessel information (fishing); point (spatial) NOTES ON QUALITY CONTROL: Scientific names listed in the survey species list have been mapped to recognized standards - marine taxa have been mapped to the World Register of Marine Species (WoRMS) using their online taxon match tool. All sampling locations were plotted on a map to perform a visual check confirming that the latitude and longitude coordinates were within the described sampling area. In 2003, because of a fire aboard the Alfred Needler, the Wilfred Templeman was used for the survey. However, no comparative fishing experiments have been conducted between the Alfred Needler and the Wilfred Templeman. We are therefore unable to integrate the indices derived for 2003 to the remainder of the survey time-series. SAMPLING METHODS: Sampling Method: Consult the "Protocols for research vessel cruises within the Gulf Region (dermersal fish) (1970-1980)" report, link provided in the citations list. USE LIMITATION: To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.

Samples were collected from October 15, 1985 through June 12, 1987 in emergent marsh and non-vegetated habitats throughout the Lavaca Bay system to characterize usage of saline coastal and brackish deltaic habitats by estuarine aquatic species. Results suggest that short term lowering of salinity does not deter estuarine organisms from using deltaic marshes, but rather long term habitat changes may cause these responses

We examined the distribution of nekton across the marsh landscape using a 1-m2 drop sampler to compare nekton densities across three different salinity zones (intermediate, brackish, saline), three pond sizes (diameter 40 msmall, 250300 mmedium, 750 mlarge), and two habitat types (pond, adjacent marsh) in the Barataria Bay Estuary, Louisiana. Nekton assemblages of ponds and the adjacent marsh appeared to be structured by the responses of individual species to the estuarine salinity gradient at the landscape scale and to pond habitat attributes locally. Our results indicate that ponds in the brackish and saline zones are more important nursery areas for most fishery species than ponds in the intermediate zone. Medium and large ponds supported higher densities of most species than small ponds. Most species of nekton were associated with vegetation structure, and individuals of these species were either concentrated among plant stems at the marsh edge or within submerged aquatic vegetation in ponds.