Document Type

Conference Paper

Publication Date


Publication Title

Proceedings of the Back Bay Ecological Symposium



Conference Name

Back Bay Ecological Symposium


A study of the subtidal macrobenthos in Back Bay, Virginia was conducted to examine community structure in relation to sedimentary and water quality characteristics. Samples were collected in August and November of 1987 and February and May of 1988 at ten stations.

From a cluster analysis of ten collection stations, three site groups were identified. Species composition between site groups was relatively homogeneous. Discriminant analysis indicated that eight species accounted for most of the variation between site groups. A comparison of plots of the biological and environmental variables in discriminant space suggested that variation in the biological data between site groups was related in part to silt-day content, organic cont~nt, and particle size of the sediment.

Three temporal groups were identified from a second cluster analysis of data averaged over all collection stations by collection date. Discriminant analysis indicated that six species accounted for most of the variation between temporal groups. Temporal variation in macrobenthic community structure was the result of reproductive and recruitment events of these six species.

Species diversity indices were similar to values obtained in oligohaline regions of the Chesapeake Bay (Dauer 1988; 1989). Community density was higher and community biomass was lower than values found in the Chesapeake Bay oligohaline areas (Dauer, 1988; 1989). Major changes in total community density and biomass were related to spatial and temporal changes in two dominant species: Chironomus riparius (Onsecta) and Scolecolepides viridis (Polychaeta).