SREL Reprint #2325

Abundance, biomass and production of aquatic invertebrates in Rainbow Bay, a temporary wetland in South Carolina, USA

Douglas A. Leeper and Barbara E. Taylor

University of Georgia Savannah River Ecology Laboratory

Abstract: The abundance, biomass and production of aquatic invertebrates were determined for 1992 and 1993 at Rainbow Bay, a small (maximum inundated area ~1.5 ha), shallow (maximum depth ~1 m) depression wetland in South Carolina, USA, which dries annually. Estimates were based on invertebrates collected from benthic substrates and the water column, including those associated with macrophytes. Mean invertebrate density during the periods of inundation was 7.1 x 105 animals/m2 in 1992 and 7.7 x 105 animals/m2 in 1993. Small taxa, including nematodes, rotifers and microcrustaceans dominated numerically. Biomass was 2.1 g dry mass/m2 in 1992, and 0.9 g/m2 in 1993. Oligochaetes, insects (mostly chironomids) and crustaceans dominated the biomass. The lower biomass in 1993 was the result of significant reductions in the biomass of oligochaetes and benthic chironomids. Laboratory-derived daily growth rates of oligochaetes and chironomids collected from Rainbow Bay, along with daily production rates for crustaceans and rotifers derived from other studies were used to estimate secondary production. Production in 1993 (14.7g dry mass/m2) was less than in 1992 (36.7g/m2) , due primarily to lower biomass of oligochaetes and chironomids in 1993. Differences between years in abundance, biomass and production were associated with differences in hydrology of the wetlands including duration of inundation, and abundances of salamanders.

SREL Reprint #2325

Leeper, D.A. and B.E. Taylor. 1998. Abundance, biomass and production of aquatic invertebrates in Rainbow Bay, a temporary wetland in South Carolina , USA. Arch. Hydrobiol. 143:335-362.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).