The effect of the substrate status on bottom fauna in Aswan reservoir, Egypt

The effect of the substrate status on bottom fauna
in Aswan reservoir, Egypt
Isaac A. Iskaros and Nazeh N. Gindy
National Institute of Oceanography and Fisheries, Aswan, Egypt
Received 19th July 2009, Accepted 30th August 2009
Abstract
This study is carried out to assess the response of benthic fauna to water quality variables as well as the substrate
status of bottom sediments in Aswan Reservoir during spring, summer and autumn of 2008 and winter of 2009. Nineteen
bottom fauna species belonging to Oligochaetae (3 species), Chironomidae (7 species), Mollusca (7 species), Hirudinea
(1 species) and Decapoda (1 species) were identified from Aswan Reservoir, of which Oligochaetae was the most
common group. The magnitude of the standing crop of bottom fauna showed that the highest counts and biomass
occurred during summer (avg. 2827 org./m2
& 11.1 gm/m2
) and autumn (avg. 5269 org./m2 & 31.0 gm/m2
) associated
with the increased amount of organic carbon (avg. 3.4 & 3.3 wt%, respectively) and calcium carbonate in the sediments
(avg. 10.06 & 9.06%, respectively). The study shows that the physico-chemical parameters and the substrate status of
bottom sediments give high standing crop of bottom fauna in Aswan Reservoir. The selection of Aswan Reservoir for
construction of a fish farm could be an important mean for increasing fish production.
Keywords: Aswan Reservoir, water quality, bottom sediments, bottom fauna, community composition