GEOCHEMICAL AND ENVIRONMENTAL STUDIES OF RECENT MARINE SEDIMENTS AND SOME HARD CORALS OF WADI EL-GEMAL AREA OF THE RED SEA, EGYPT

GEOCHEMICAL AND ENVIRONMENTAL STUDIES
OF RECENT MARINE SEDIMENTS AND SOME
HARD CORALS OF WADI EL-GEMAL AREA
OF THE RED SEA, EGYPT
HASHEM ABBAS MADKOUR
Marine Geologist (Researcher), National Institute of Oceanography and Fisheries, Hurghada
Research Station, Red Sea branch.
Keywords: Geochemical, Marine sediments, Hard corals, Wadi El-Gemal, Heavy metals,
Natural impact.
ABSTRACT
The distribution of (Fe, Mn, Zn, Cu, Pb, Ni, Co and Cd) concentrations were
determined in surface marine sediments and coral reefs at Wadi El-Gemal in the Red Sea
area. There were significant differences in concentrations of heavy metals in the marine
sediments relative to the coral reefs. Some heavy metal concentrations in sediments and
coral reefs in the study area are high compared to that in the impact areas of the Egyptian
Red Sea coast. The results indicate that the high concentrations of heavy metals in marine
sediments and coral reefs are particularly affected by the high contribution of terrigenous
materials through the stream of Wadi El-Gemal. Generally, heavy metals concentration in
the sediments decreased with increasing distance from the shoreline with the exception of
Pb, which increased with increasing distance from the shoreline. On the other hand, Pb
concentration in coral reefs is high compared to that in some sediment samples at Wadi ElGemal area.
The grain size, carbonate, organic matter, phosphorus and heavy metals distribution
reflect marked changes in lithology, biological activities in the sea and land geology of the
study area. Carbonate content mainly of biogenic origin varies from 5.7 –69.5% of the
sediments. Organic matter contents of the sediments (1.7 to 6.5%) and phosphorus content
(110 to 5097ppm) usually reflect significant terrigenous influences. On the other hand,
heavy metals show an increasing tendency in the mud fraction of Wadi El-Gemal area.
The present work reflects how much the marine sediments and coral reefs are
influenced by natural impacts from this wadi. The collected data will be useful in
management and suitable development of the area, beside being helpful as database in the
future