Among the many egregious scientific inaccuracies of 'Finding Nemo' - fish can talk, sharks form support groups, turtles wax their shells - perhaps none is more glaring than the conceit of fish maintaining friendships. As many a marine biologist has noted, fish aren’t in it to make friends - they’re in it to survive and reproduce.

But scientists are uncovering a fascinating exception in coral reefs, not unlike the one Nemo called home: Here fish of various species band together, developing social networks exactly to survive and reproduce. By arranging underwater cameras on a plastic scaffolding above reefs, and using algorithms inspired by video games to determine where the fish are looking, the researchers modeled how individual fish monitor each other’s movements to determine whether an area is safe or dangerous. These social networks make it safer for fish to gobble up the algae that would otherwise choke coral reefs if they weren’t around to keep it in check. If too much algae grows, it keeps light from reaching the corals, preventing them from harvesting the sun’s energy. Break up this social network by overfishing, and the consequences ripple across the whole ecosystem, the researchers argue in a new paper published Monday in the Proceedings of the National Academy of Sciences.