BENTHIC FAUNA OF MARYOUT LAKE

BENTHIC FAUNA OF MARYOUT LAKE
By
SAWSAN M. ABOUL EZZ” AND NAGWA E. ABDELAZIZ
*NationalInstitute ofOceanography and Fisheries, Alexandria, Egypt.
Key words: Maryont Lake, Benthic fanna, Diversity IndeL
ABSTRACT
The Benthic community of Maryout Lake was studied bimonthly
from November 1995 to September 1996 through Alexandria.
Wastewater Project Phase II (United States Agency International
Development U USAlD ”). The Samples were collectedfrom four main
basins of the lake namely; Fishery, Main, Northwest and Southwest
Basins.
Thirty-eight taxa were identified The gastropods composedmore
than 75% ofthe total numbers ofbottomfaunafollowed by insects.
Each basin ofthe lake was somewhat identical with the exception
of the Southwest Basin, where insects dominated its community. The
Fishery, Main and Northwest Basins were dominated by the minute
gastropods specially the genus Hydrobia and less so by Paludestrina
and Pomatiopsis. The Southwest Basin differed in that its high density
of benthic animals was insect pupae or larvae ofchironomids and
large number of coarctate insect pupae that is excludedfrom
calculations.
The densities of benthic animals were nearly similar among the
Southwest, Northwest and Fishery Basins (9 x 1rf, 12 x 1(/ & 11 x
lrf organisms/m2 respectively). Density of the Main Basin was
markedly low (937 organisms/m2
). The benthic community ofthis
basin reflects the polluted condition. The high level of nutrient
inflows and extensive areas .of low or depletion ofdissolved oxygen
contribute to the relatively depauperate benthicfauna -there.