Evaluation of Iraqi coasts using littoral and marine bivalve shells

الملخص EN

The geochemical analysis of both of Crassostrea cucullata and Chione californensis shells and hydrochemical analyses of water are carried out to study the environmental evaluation in the Iraqi coasts.

Shells and water are collected during low tide period (March to August 2011), from seven different stations (Fadakia, Rass AlBishah, Khor Abdullah, Khor Shytianah, Hacham Island, Khor AlZubair and Shatt AlBasrah).

The hydrochemical analyses reflect two zones of water salinity, Fadakia and Shatt AlBasrah of brackish water with TDS range (15148 – 18130 ppm), and the other marine coastal sites of saline water with TDS range (34123 – 45220 ppm).

XRD of shells of Chione californensis reveals that they have two layers, an inner layer constitutes of aragonite and outer layer constitutes of calcite, while the shells of Crassostrea cucullata have only calcite layer.

Water salinity increasing associate with increase of major chemical constituents of oyster shells.

Mg/Ca and Sr/Ca values in the coastal line Crassostrea cucullata shells are higher than Fadakia and Shatt AlBasrah shells that may be due to increment of salinity in the coastal line compared with Fadakia and Shatt AlBasrah areas.

Zn, Cu, Pb, Sr, and Cr metals in Khor Shytianah Crassostrea cucullata are higher than the other areas may attribute to higher contamination in this area.

The chemical constituents of CaO%, MgO, Sr/Ca and Mg/Ca in Khor Shytianah and Hacham Island Chione californensis shells are higher than Khor Abdullan shells, this result may be indicator to higher salinity of sea water in Khor Shytianah and Hacham Island compare with the sea water of Khor Abdullah.

Heavy metals (Co, Ni, Rb, Sr, Zn, Ba, Cr, Th, Mo, and Pb) in Khor Shytianah Chione californensis shells were more than the other shells may be due to high range of contamination of sea water by this metal.