Categories
vol-25DISTRIBUTIONAND ABUNDANCE OF BENTHICASSEMBLAGES·
IN EL-GAMIL BASIN (LAKE MANZALAH, EGYP1)
A) MEIOBENTHOS
BY
MOHAMED R. A. FISHAR*
*Nationallnstitute ofOceanography &Fisheries, Inland Water &,Aquaculture Branch
Key words: Meiobenthos, Lake Manzalah, distribution, composition.
ABSTRACT
Meiobenthic fauna ofEI-Gamil Basin were studied during summer
and winter of 1997 from 20 stations belonging to three sections. ‘
Sediment grain size analysis and organic matter content were
determined at each station together with some environmental
parameters ofwater.
Secchi disc readings showed a remarkable decrease in stations
affected by discharge ofwastewater. pH values were on the alkaline
side and varied between 9 and 8.1. Dissolved oxygen concentration
was high during winte,.. The highest values ofsalinity were recorded
at section opposite to Boughas EI-Gamil. Bottom sediments ofthe
area were nearly homogenous composed mainly ofclay loam at most
localities. Organic matter was relatively high and variedfrom 6.98 %
to 2.21%.-
Meiobenthic community consisted mainlyfrom four main groups,
Foraminifera, Ostracoda, Nematoda and Copepoda in addition to
small numbers ofannelids, fish eggs and larvae ofmacrobenthos. The
discharge of wastewater treatment plant decreased the number of
individuals and species (diversity) in stations opposite to the
discharge point. Distribution of meiobenthic taxa was closely
correlated with organic matter, higher muddy content in the sediment
and salinity.
