Fish is an extremely important component of the human diet in many parts of the world and provide nutrients such as protein,omega-3 (n-3) fatty acids (that reduce cholesterol levels and the incidence of heart disease, stroke, and preterm delivery) and others that are not easily replaced Fish can be preserved in so many ways including reezing,salting, pickling, smoking and drying.But the most useful way of preserving seafood is through canning.Canned products especially canned fish have been found to contain increasingly high amounts of Hg, Pb and Cd as well as some other heavy metals. These metals are considered the most important form of pollution of the aquatic environment because of their toxicity and accumulation by marine organisms; and also because of their persistent and being not easily biodegradable in nature.Metal pollution of the sea is less visible and direct than other types of marine pollution but its effects on marine ecosystems and humans are intense and very extensive