A Proposed Esturaine Classification: Analysis of Species Salinity Ranges

Nelson, David; Monaco, Mark; McCormick-Ray, M.; Hayden, Bruce; Bulger, Arthur

This report presents results of a statistical analysis of the salinity ranges of fish and invertebrates that use estuaries in the Mid-Atlantic Region. The analysis was conducted jointly by NOAA's Strategic Assessment Branch and the University of Virginia's Department of Environmental Sciences. The project was undertaken to provide additional information toNOAA's Estuarine Living Marine Resources (ELMR) project (see inside front cover). This project uses salinity zones to organize information on the spatial and temporal distribution of species within estuaries. The results presented will aid in the interpretation of the ELMR information under development, and may provide an improved framework to organize information on estuarine species distributions. Data were compiled and analyzed on the salinity ranges of 317 species/life stage combinations in the Mid-Atlantic Region. Results indicate that five over- lapping salinity zones (freshwater to 4 parts per thousand (ppt) , 2-15 ppt, 11-19 ppt,15-28ppt, and 23 ppt to marine waters) can be used to represent how fish and invertebrates are distributed within estuaries in this region. Species assemblages were also identified based on the salinity zones they use in common. The scheme presented is an attempt to develop an estuarine salinity classification based on a multivariate statistical analysis of reported field distributions of species. The analysis is compared to the Venice System (Symposium 1959) of estuarine salinity classification.