Environmental Influences on Estuarine Benthic Community Dynamics

Benthic invertebrate communities, composed of sessile, relatively long-lived species, provide a record of effects of short- and long-term environmental changes through species composition and abundance changes. Thus, they are often used as water-quality indicators. However, their use in water-quality studies requires assumptions that communities remain at steady state except when influenced by human activity. Long-term studies show that natural variation over a variety of time scales often masks human-induced changes. Estuarine benthic communities, often dominated by suspension feeders, have an unknown but potentially large controlling effect on phytoplankton biomass, and thus may be important in limiting eutrophication. Objectives of this project are (1) to characterize long-term patterns in estuarine and coastal benthic communities in order to determine the contribution of natural factors (climatic events, seasonal/interannual patterns of runoff, water chemistry, and circulation, sediment texture and stability, and food availability) to community variability, and to assess the contribution of human activity (waste contamination, control of river runoff) to the remaining unexplained variability in community dynamics; and (2) to measure, through field and laboratory studies, the processes which determine the rates at which invertebrates remove phytoplankton from the water column.

REPORTS PUBLISHED 2000-2003

Nichols, F.H., 2003, Interdecadal change in the deep Puget Sound benthos: Hydrobiologia, v. 493, p. 95-114. (on-line abstract)

Brown, R.L., Nichols, F.H., and Smith, R.L., 2000, CalFed Bay-Delta Program science conference 2000 summary: Summary of a meeting held on October 3-5, 2000, in Sacramento, California, 48 p. (on-line report)

Hornberger, M.I., Luoma, S.N., Cain, D., Parchaso, F., Brown, C., Bouse, R., Wellise, C., and Thompson, J., 2000, Linkage of bioaccumulation and biological effects to changes in polutant loads in South San Francisco Bay: Environmental Science and Technology, v. 34, p. 2401-2409. (on-line abstract or on-line pdf file - published by the American Chemical Society; not subject to U.S. copyright.)

For information on current projects in the National Research Program, see Indexes to NRP projects and bibliographies