In the warm waters emanating from Ontario’s largest nuclear plant, fish are gathering by the thousands. Ahead of an Earth Day livestream, CBC News got a rare look at what some call a ‘fish city,’ a striking scene scientists say may signal a changing Great Lakes ecosystem.

When Dublin scientist Emma Murphy got word that a dead Greenland shark had washed up on the shores of northwestern Ireland, she was gobsmacked. Not only are the massive and ancient ocean dwellers notoriously elusive, but they usually make their homes in the remote depths of the Arctic and North Atlantic oceans.

An unusually large troop of chimpanzees displayed cooperation and social cohesion for decades, until something shifted and they started to turn on each other.