An estuarine benthic index of biotic integrity for the Mid-Atlantic region of the United States. I. Classification of assemblages and habitat definition

摘要: An objective of the Mid-Atlantic Integrated Assessment Program (MAIA) U.S. Environmental Protection Agency is to develop an index for assessing benthic community condition in estuaries mid-Atlantic region United States (Delaware Bay through Pamlico Sound). To such index, natural unimpaired communities must first be identified and variability related factors accounted for. This study focused on these two objectives; Lnanso et al. (2002) describe index. Using existing data sets from multiple years, classification analyses species abundance discriminant analysis were employed identify major habitat types MAIA evaluate physical characteristics that structure infaunal assemblages. Sampling was restricted soft bottoms development period, July early October. The revealed salinity sediment composition as structuring assemblages estuaries. Geographical location a secondary factor. Nine classes distinguished combination 6 classes, 2 types, separation North Carolina Delaware-Chesapeake polyhaline sites. effect faunal sites, which separated into groups above below 90% sand content. Assemblages corresponding each 9 habitats context widely recognized patterns dominant taxa. Differences between attributed relative contributions not differences composition. No zoogeographic discontinuities could identified. Our results reinforce findings recent studies suggest that, with respect estuarine assemblages, boundary Virginian Carolinian Provinces moved new south Sound.