Seafood, in particular fish are a good source of protein and omega 3 fatty acids. As well these beneficial nutrients, seafood can contain trace amounts of different metals. Heavy metals present in water both naturally and introduced to the water system are absorbed by animals living in that environment. While trace elements are found in most seafood, much higher levels are found in predatory sea animals, due to the cumulative effect of their consumption. Analysis of trace metals is important to remain compliant with different countries food laws.