It is estimated that up to a third of shark species are under threat of extinction. Human activities such as shark finning and commercial fishing are the main reason for the decline in populations. Fins from up to 73 million sharks end up in shark fin soup yearly and you see sharks being caught up in fishing nets unintentionally.
Another of the seas creatures, fish, are under threat. An estimated 5 percentage of the worlds known fish species are endangered. The main reason is overfishing but issues like pollution and habitat loss also play a significant role in their decline.