EFFECT OF ECOLOGICAL AND BIOLOGICAL FACTORS ON THE UPTAKE AND CONCENTRATION OF TRACE ELEMENTS BY AQUATIC ORGANISMS AT EDKU LAKE

EFFECT OF ECOLOGICAL AND BIOLOGICAL FACTORS ON
THE UPTAKE AND CONCENTRATION OF TRACE ELEMENTS
BY AQUATIC ORGANISMS AT EDKU LAKE
LAILA M. SHAKWEER AND M.M. ABBAS
National Institute of Oceanography and Fisheries, Alexandria, Egypt
Key words: Trace elements – Edku Lake – Fish – Aquatic plants – pollution.
ABSTRACT
The effect of temperature, pH and trace elements concentration in the ambient water on
the uptake and accumulation of Cu, Zn, Ni and Pb in various organs of fish and parts of
aquatic plants of Edku Lake were studied. It was found that higher water temperature and
lower pH during summer increased the rates of trace metals uptake by the most common
fish species Oreochromis niloticus.
The concentrations of Cu, Zn, and Ni in the various organs of fish were affected by the
concentrations of these elements in the water.
Cu, Zn, Ni and Pb attained higher concentrations in the roots of Eichormia crassipes if
compared with their concentrations in the other parts of this aquatic plant. Sex of fish can
be considered as an important factor affecting the accumulation of trace elements in
different organs of fish. The accumulation of Cu, Zn, and Ni in the flesh, liver, gonads and
bones of fish were negatively correlated with length of the fish.