IMIS

Benthic Grab Information, Benthic Replicate Abundance data, Benthic Summary Data by station characterize the benthic grab data from samples collected in National Coastal Assessment (NCA) Estuaries. These data were collected from 2000-2004 for the marine coastal states of the contiguous United States, Alaska, Hawaii, and the US territories of Puerto Rico and the Virgin Islands. For Benthic Grab Information, one record is presented for each grab collected at a station. The size of the grab sampler used to collect the sediment is reported, as well as the size of the area sampled. The Benthic Replicate Abundance data report the abundance of each benthic taxon found in grab, including the taxonomic name. The Benthic Summary Data reports summary data for each station, including total number of taxa and infauna taxa identified, total abundance of all organisms and total abundance of infaunal organisms. The National Coastal Assessment (NCA) is a national monitoring and assessment program with the primary goal of providing a consistent evaluation of the estuarine condition in U.S. estuaries. It is an initiative of the Environmental Monitoring and Assessment Program (EMAP), and is a partnership of several federal and state environmental agencies, including: EPA's Regions, Office of Research and Development, and Office of Water; state environmental protection agencies in the 24 marine coastal states and Puerto Rico; and the United States Geological Survey (USGS) and the National Oceanic and Atmospheric Agency (NOAA). The five-year NCA program was initiated in 2000, and is also known as the Coastal 2000 Program. Stations were randomly selected using EMAP's probabilistic sampling framework and were generally sampled once during a summer index period (June to October). A consistent suite of indicators was used to measure conditions in the water, sediment, and in benthic and fish communities. The measured data may be used by the states to meet their reporting requirements under the Clean Water Act, Section 305(b). The data will also be used to generate a series of national reports characterizing the condition of the Nation's estuaries. A general overview of sampling procedures follows. One 'grab' sample was collected from each station using a Young-modified Van Veen or other comparable grab sampler. The grabs were nominally 440 cm2 in area and 10 cm deep. A sub-sample 2.5 cm in diameter and the depth of the grab was taken from each grab for grain-size analysis. The remaining sediments were live-sieved in the field with a 0.5 mm mesh screen. Organisms retained on the screen were placed in plastic containers and fixed in 10% buffered formalin with rose bengal stain for preservation. All taxa in a grab sample were sorted by a technician and then identified and counted by a skilled taxonomist. Only organisms larger than 0.5 mm were processed.