Northern Prairie Wildlife Research Center
Institute for Wetland and Waterfowl Research, Ducks Unlimited, Stonewall P.O. Box 1160, Oak Hammock Marsh, MB, R0C 2Z0 Canada
Research on wetland invertebrates has been hindered primarily by a combination of the absence of background information and the problems associated with quantitative sampling of wetland habitat. The Marsh Ecology Research Program studied the responses of benthic, nektonic and emerging invertebrates to water-level manipulations in a series of experimental marsh cells during 1980-89. Shifts in the abundance and distribution of aquatic invertebrates were often the result of two or more interacting factors, such as the availability of food resources and habitat. Changes in emergent vegetation as a result of water-level manipulation had a direct effect on the presence of submersed vegetation, algae communities, and the quality and quantity of litter introduced into the experimental cells. These factors, combined with abiotic influences, determine the distribution and abundance of invertebrates in wetland habitats.