Krill are sinking and Antarctic land fauna may be suffering eye damage as a result of a seasonal hole in the ozone layer over the Antarctic. The hole isn't new. In fact, it has form. It was discovered in the mid-1980s by scientists from the British Antarctic Survey and was much bigger then than now, caused mainly by chlorofluorocarbons used in household fridges. CFCs were outlawed by the Montreal Protocol of 1987, which is considered the most effective environmental treaty ever and led to a dramatic shrinkage of the hole. But it couldn’t prevent a sharp increase in forest fires in Australia as a result of climate change, which seem to be to blame for a recent expansion of the hole. (It appears smoke particles, like CFCs, can start chemical reactions in the atmosphere that destroy ozone especially quickly in the ultra-cold air over Antarctica.) The krill are moving deeper to get out of the sun, making them harder for whales, seals and penguins to find.