Fish accustomed to the salty water of the Arctic may have to think about finding a new home.

As a result of global warming, the Arctic Ocean has been getting less salty over the past half century and the trend looks set to continue. The culprits are a massive increase in rainfall over the Arctic and faster melting of sea ice and glaciers.

Bruce Peterson of the Marine Biological Laboratory in Woods Hole, Massachusetts, and his team gathered decades’ worth of meteorological, river, sea-ice and glacier data from the Arctic region and used it to calculate the increase in fresh …