Salmon runs in hot water?

摘要

Adult salmon and trout (collectively 'salmonids') are famous for their reproductive migrations - the salmon runs. They often swim thousands of miles to reproduce in their original spawning grounds. This is a vitally important journey-not only for the fish. Migrating salmonids are a predictable food source and bring nutrients to rivers and lakes. Predators such as bears anticipate the arrival of this bounty and time their own lives around it. Salmonids are also an important economic resource for humans.