Northern Prairie Wildlife Research Center
South Dakota Cooperative Fish and Wildlife Research Unit, South Dakota State University, Wildlife and Fisheries Sciences Department, P.O. Box 2206, Brookings, SD 57007
Wetlands are considered among the most productive habitats on earth. Prairie pothole wetlands have historically produced much of the waterfowl in North America. These wetlands support a diverse community of aquatic invertebrates which are thought to represent a high protein food source for nesting ducks and ducklings. However, production of aquatic invertebrates in northern prairie wetlands has not been measured previously.
We investigated aquatic invertebrate abundance, biomass, and production of four semipermanent northern prairie wetlands in 1989. The objectives of this study were to determine aquatic invertebrate community production in these wetlands and productivity/biomass ratios of common taxa. Aquatic invertebrates were collected from May through October 1989 using a 7.6 cm diameter core. Animals were enumerated to genus or species and measured to nearest 0.1 mm. Biomass was calculated from length to dry-weight relationships for specific taxa. The size-frequency method was used to calculate production. Seventy-four taxa were collected. Annual mean abundance among the four wetlands ranged from 4,782 to 20,063 individuals/m2. Mean biomass ranged from 1,543 to 5,428 mg/m2. Community production ranged from 4,604 to 21,800 mg/m2 and was correlated (r2 = 0.77) with duration of flooding. Chironomidae, Oligochaeta, and Gastropoda were the most abundant taxa and contributed the most to total biomass and production.