The main threat to the welfare of individual marine animals and the conservation of their species is human activity.
100 million sharks are killed each year for fins (for soup and ‘trophies’ in the Far East), but also for flesh, liver oil and skin. Local basking shark populations have been hunted near to extinction. They have UK protection but none elsewhere. Since 2002 they are CITES* Appendix II, but this only monitors not prohibits trade so better safeguards are needed.
Over-exploitation for meat, shells and eggs, plus disturbance of nesting beaches and marine pollution have decimated global populations of all seven species. Populations recover slowly; turtles do not mature until 30 years and one egg in a thousand survives to adulthood.
The gentle dugong is defenceless against exploitation and has been extensively hunted for meat and oil. Other dangers include accidental entanglement in fishing nets and habitat disturbance by destructive fishing practices. Thought to be Africa’s most endangered large mammal.
Tens of thousands of dolphins drown each year in fishing nets, plus over-fishing has diminished their food stocks. Other threats include their accumulation of toxins, habitat destruction and noise pollution. Wild dolphins are regularly caught for the captive industry, and while whaling was banned in 1986, Japan and Norway ignore the ban and campaign to legalise whaling again.
All seven species of marine turtles and are endangered. Basking sharks and dugongs are IUCN1 listed as ‘vulnerable to extinction’. The orca is not thought to be endangered but local populations are under threat.