Pinctada radiata (Pearl Oyster) : A bioindicator for metal pollution monitoring in the qatari waters (Arabian Gulf)

Bivalves are extensively used in monitoring programmes in the marine environment due to their ability to concentrate pollutants to several orders of magnitude above ambient levels in sea water. Commonly, the levels of contaminants accumulated in the tissues has been used to indicate the degree of chemical contamination in the environment. Trace metals are the main sources of metals toxicity in the marine environment by entering the food chain and thus affecting the ecosystem. The marine ecosystem off Qatar has been recently subjected to the direct release of urban and industrial runoff from major centres. Such inputs are known to contain trace metals which lead to increased metals concentrations in the coastal zone, some of which are toxic and can endanger human health. A wealth of knowledge exists for heavy metals in bivalves in many areas of the world while little appears for the Arabian Gulf species. In the present study an attempt has been made to analyse the metal accumulation in the abundant bivalve P. radiata in order to test its potentiality as sentinel accumulator of heavy metals from the marine environment around Qatar. It could be considered as a first step in developing a regional programme for monitoring metals in the Gulf environment.