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 [...]
Summary
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.
