The study of benthic fauna: Maple River impoundment project.

Abstract

From the qualitative and quantitative study of the benthic fauna of the impoundment, we may determine that the impoundment area is rather rich in productivity, especially in the west branch. In the impoundment itself very productive in the central area through the eastern part bay. The sandy littoral zone around the impoundment quite low in productivity and organisms, and always steep in profile. A large number of empty sandy cases of caddisflies (Pseudostenophylas sp.) are found in this area. The distribution of benthic animals in the impoundment can be determined as follows: Planaria - found at vegetation zone; shallow and silty sediments. Oligochaeta - only deeper part; sand and clay bottom; no vegetation. Isopoda - widely distributed in every depth, but very condensed at vegetation zone and shallow. Amphipoda - small in number but widely distributed at various depths. Chironomidae - widely distributed; found in every depth and every kind of sediment in the large number. Clam - abundant along the littoral zone only (sandy place). Snails - very few in number, mostly at the littoral zone. Hydracarina - widely distributed and rather constant in number.