Commercial Fish and shellfish

Commercially exploited fish and shellfish are all living marine resources targeted for economic profit such as the bony fish, sharks and rays (known as elasmobranchs), crustacean such as lobsters and shrimps, and molluscs (including bivalves, cuttlefish and squid). It also includes other creatures such as jellyfish and starfish.

Good Environmental Status is achieved for a particular stock only if all of the three attributes are fulfilled. This implies that all commercially exploited stocks should be in a healthy state and that exploitation should be sustainable, yielding the Maximum Sustainable Yield (MSY). MSY is the maximum annual catch, which can be taken year after year without reducing the productivity of the fish stock.

Heavy fishing pressures, such as overexploitation or overfishing, can have very negative environmental impacts. They can result in the loss of significant potential yield of the stocks being fished and can even precede severe stock depletion and fisheries collapse. Because of overfishing, fish stocks can reduce dramatically to the point where they lose internal diversity and with it, their capacity to adapt to environmental changes. Fish communities can be altered in a number of ways, for example they can decrease if particular-sized individuals of a species are targeted, as this affects predator and prey dynamics .