Coral reefs the world over are threatened by pollution, rising ocean temperatures, and over fishing. In Cuba, however, reefs are flourishing. This video from Nature follows a marine biologist as he explores the variety of corals, fish and other wildlife in Cuba’s tropical waters, and considers why Cuba’s reefs are so healthy in comparison with those in the rest of the world.

This video is available in both English and Spanish audio, along with corresponding closed captions.