Trace elements in offshore and inshore fish from the mediterranean coast of Israel

A baseline survey of the levels of heavy metals in selected species of fish was conducted from 1975 in offshore, and since 1980 in inshore commercial species. The area of study covered the coastal waters of the Mediterranean between 30–90 m depth. Ranges of concentrations (μg g^‐1 wet wt.) of mercury (<0.01–1.12), cadmium (<0.01–0.11), chromium (<0.01–0.70), copper (0.05–1.39), zinc (1.94–10.0) and iron (1.89–7.72) were determined in twelve trawl fish species collected from five locations offshore by deep trawl. The levels of lead and nickel were generally near the detection limit, so no analysis for these elements in the edible muscle tissues was carried out. The mercury concentration was found to increase with length and weight of the fish. Mercury levels did not vary in the fish among the five stations sampled.

Non‐migratory species were selected for the study of inshore fish (Diplodus sargus, Lithognathus mormyrus and other commercial species). Ranges of mercury varied between < 0.005–1.02, cadmium <0.01–0.06, copper 0.17–1.01, zinc 2.05–8.87 and iron 1.72–10.8. Lead was undetectable. Mercury levels were higher in fish from Haifa Bay than in the same species collected south of the bay. Mercury in the fish increased with size, as in the trawl species.

The detailed data on the concentration of six elements in the commercial sea fish do not show inordinately high levels in the muscle tissue.

Key words:

• Heavy metals
• marine fish
• eastern Mediterranean