Benthic studies of waterfowl breeding habitat in south-western New South Wales. I. The fauna

Abstract

Murrumbidgil Swamp and Lake Menimajeel are shallow waterbodies associated with the Lachlan River and are typical of waterfowl breeding habitat offered by the Murray-Darling Rivers system. Chironomid larvae dominated the benthic fauna of mud, stick and plant substrata at both sites, numerically accounting for 96% and 49% of all animals sampled from mud in Murrumbidgil Swamp and Lake Memmajeel, respectively, 91% and 96% of animals sampled from sticks, and 96% of animals sampled from plants (Lake Memmajeel only). Lurnbriculus variegatus and ceratopogonid larvae were also important in the fauna of mud. Mud supported higher densities of animals than did sticks or plants. Over the whole study, average biomass of animals from mud of Murrumbidgil Swamp was 3600 (2860 excluding shells) mg dry wt m-2 and Lake Memmajeel 3230 (2970) mg dry wt m-2, with annual differences occurring within each waterbody and associated with stages of the wetting-drying cycle.