Abstract:
The numerical and proportional distributions of zoobenthos in lake Uluabat, which
is located in the Northwestern part of Turkey and having international importance
according to the Ramsar Convention, were determined from August 2004 to July
2005 at monthly intervals (except for December 2004, January and February 2005) at
12 different stations. Thirty-three taxonomic groups were recorded. It was found that
the zoobenthos consisted of 35.6% Oligochaeta, 27.7% Nematoda, 12.3% Chironomidae
larvae, 10.7% Gastropoda, 3.6% Ostracoda, and 10.1% Varia by numbers (Bivalvia,
Ceratopogonidae, Hirudinea, Odonata, Ephemeroptera, Asilidae, Hydraacarina, Hemiptera,
Argulidae, and Gammaridae). The average number of invertebrates was 160
individuals for 33 taxa at the 12 different stations. Also some environmental parameters
of the lakewater were analyzed (temperature, pH, dissolved oxygen, biochemical
oxygen demand, chemical oxygen demand, NO2–N, NO3–N, NH3–N, PO4
– 3, fecal coliform,
and total coliform). The relationships between the dynamics of the Oligochaeta
and the physicochemical variables were supported by the Pearson correlation index
and the canonical correspondence analysis (CANOCO). It was found that the relation
between the average number of P. hammoniensis and P. albicola (p a 0.05, r = 0.590 and
0.593, respectively) and L. hoffmeisteri (p a 0.01, r = 0.777) was directly proportional
while the relation between the average number of some taxa Trichodrillus sp., Rhyacodrilus
coccineus, Nais communis, N. variabilis, and N. barbata and NO3–N (p a 0.05, r = –0.685)
was inversely proportional.
