Bioaccumulation of Some Hazardous Heavy Metals in Three Edible Fishes Caught from Gorgan Bay, Caspian Sea

A survey was conducted to evaluate heavy metal accumulation in edible fishes caught from Gorgan Bay, as a part of the Caspian Sea ecosystem. Fish samples including mullet, roach, and common carp were just randomly prepared from fishing locations in three different areas of Gorgan Bay including estuary, channel, and Miankale wetland twice the fishing seasons. A total of 135 samples were measured using an atomic absorption spectrometer to 4 heavy metals of arsenic (As), lead (Pb), cadmium (Cd), and copper (Cu) (a total of 540 metal samples). The highest accumulation of As was related to the mullet of estuary, and the lowest contamination was related to the mouth of the channel. In relation to Cd, the highest pollution in all three species related to the fishes caught from the estuary and the lowest accumulation related to the Miankaleh wetland. In the case of metal Pb, results showed the most contamination related to the Mullet caught from Miankaleh wetland and the lowest accumulation related to the roach of the mouth of the channel. In all three fish species, the highest contamination of Cu was in the estuary and the lowest was in the fish caught from Miankaleh wetland. In general, the highest accumulation belonged to all three species located in estuaries. The probable reason can be pouring river pollution to the bay more than wetlands and channel. Due to the enclosure of the Caspian Sea and consequently the Gulf of Gorgan, limiting the fishing times and points to the periods of least incoming pollutants is very helpful for public health, especially food hygiene and fishing from this ecologically sensitive and vulnerable basin.