Goliath Grouper: Cows of the Sea - David Doubilet

In biology, appearances are often deceiving. National Geographic photographer David Doubilet tells the story of how goliath grouper, which are endangered, gather by the hundreds to spawn. The slow-moving fish had been targets for spear-fishermen for years because they weigh up to 400 pounds and don't avoid humans in the way that other fish would. Their meat is now full of mercury, so they're bad eating anyway, but Doubilet calls fishing for the goliath grouper a "fool's quest," because they put up as much resistance to being hunted as a cow in a field would.