Habitat and Conservation

Habitat

Sharks are found in all seas. They generally do not live in freshwater. Sharks are common down to depths of 2,000 metres and some live even deeper, but they are almost entirely absent below 3,000 metres. However, the deepest confirmed report of a shark is a Portuguese dogfish at 3,700 metres.

Conservation

The majority of shark fisheries around the globe have little monitoring or management. The rise in demand for shark products increases pressure on fisheries. Stocks decline and collapse because it is difficult for sharks to breed rapidly enough to maintain population levels, given the long interval between birth and sexual maturity. Major declines in shark stocks have been recorded—some species have been depleted by over 90% over the past 20–30 years with a population decline of 70%. Other threats include habitat alteration, damage and loss from coastal development, pollution and the impact of fisheries on the seabed and prey species. Shark finning attracts much controversy and regulations are being enacted to prevent it from occurring. Even though many governments and the UN have acknowledged the need for shark fisheries management, little progress has been actually made due to their low economic value.