A study has found that climate change is forcing hundreds of commercially valuable fish stocks north.
The paper, published by a scientist at the University of British Columbia, says that Arctic waters are likely to see more species of valuable fish in greater numbers.
But the same effect could hollow out fisheries in the tropics, where people depend heavily on seafood.
Author William Cheung says fish species are moving north at the rate of at least 15 kilometres a decade.
He says that movement has been happening for years and is already creating fisheries issues in some countries.