Many marine species are at risk from overfishing, climate change and harmful fishing methods. Endangered sea turtles are caught unintentionally, as bycatch, by fishing boats around the world. Shark populations are plummeting as they are killed for their meat, fins and liver oil. Coveted seafood species including tuna and salmon are threatened by overfishing, and corals are increasingly threatened by bottom trawls and climate change. Learn about more ocean creatures in the Explore the Oceans section.