Document Type



Virginia Institute of Marine Science

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The disposal of dredged material from channel deepening projects is a major anthropogenic process influencing· benthic communities of coastal aquatic systems. Such activities are important because benthic subsystems and component organisms play major roles in the functioning of estuarine ecosystems. Benthic invertebrates are major prey items in the diets of fishes and crabs (Arntz and Brunswig 1975, Virnstein 1977, Arntz 1978, Blundon and Kennedy 1982, Lunz and Kendall 1982, Moeller et al. 1985, Pihl et al. 1992). As secondary producers capable of utilizing trophic resources from a variety of sources (e.g. detritus, algae, bacteria), they provide important links to higher trophic levels. From microbes to macrofauna, benthic organisms also have major impacts on the cycling of nutrients (Diaz and Schaffner 1990, Mayer et al. in review), contaminants (Lee and Swartz 1980, Diaz and Schaffner 1990, and Schaffner et al. 1992), and sediments (Rhoads and Boyer 1982, Diaz and Schaffner 1990).

Macrobenthic organisms exhibit many properties that make them good indicators of environmental conditions (e.g. limited mobility, a variety of life histories, a range of physiological tolerances). Numerous studies have demonstrated that spatial and temporal comparisons of the kinds and abundances of benthic organisms are sensitive and important methods for assessing dredge material disposal effects on aquatic systems.

This study documents changes in the structure of lower Chesapeake Bay macrobenthic communities affected by dredged material disposal. The Corps is completing an assessment of changes in benthic resource value at the Wolf Trap Alternate Disposal Site using the Benthic Resource Assessment Technique (BRAT).


Dredging spoil -- Environmental aspects -- Chesapeake Bay (Md. and Va.), Benthos -- Chesapeake Bay (Md. and Va.)