Paul Watson, the founder of Sea Shepherd Conservation Society, is best known for using direct action to protect whales from Japanese whaling vessels, but he’s also a world-renowned advocate for the oceans and all of its other inhabitants. During an interview with TheirTurn in New York City, Watson explained why protecting the oceans is not only vital to sea animals but also to the very survival of the human species. “If the oceans die, we die.”

Watson explains that oceans, which he describes as the “blue lungs” of the Earth, produce 70% of the oxygen that we breathe and that the source of the oxygen are phytoplankton. Since 1950, the amount of phytoplankton in the oceans has dropped by 40% due to whaling, commercial fishing, animal agriculture and other forms of pollution.

Watson is the subject of new award-winning documentary film, Watson, that chronicles his career as an eco-warrior on the high seas. Watson is available on Animal Planet.