The University of B. C. researchers have found that sprinting among sockeye salmon through fast and turbulent water can lead to the fish having cardiac arrest. The research is part of five-year study funded by BC Hydro, a Canadian electric utility in the province of British Columbia.

To discover about the fish, scientists of University of British Columbia tagged accelerometer transmitters to 63 fish. The transmitter records the swimming speed of fish and the level of oxygen they consume. The fish were released to swim in Seton Dam, dam on the Seton River in British Columbia. The fish were then tracked to their spawning grounds.

Research biologist at University of British Columbia and lead author, Nicholas Burnett, said that when the fish passed through fast and turbulent water, they started to die of cardiac arrest. Only 25 fish reached their spawning grounds. The study has found that the fish that preferred burst swim through fast water died of cardiac arrest.

Burst swimming is an act of swimming fast when fish pass through fast and turbulent water. To swim in that water, fish require extra oxygen and energy. The act increases lactic acid in the blood of fish that could lead to heart attack.

Nicholas Burnett said, "We were focusing on just one challenge or hardship these fish face so these fish had already travelled about 400 kilometres and then they encounter the dam".

Burnett said it was the first time when they have noticed salmon dying due to burst swimming. Scientists have also found that high temperature of water could increase problems for fish.

Burnett have suggested that in order to keep sockeye salmon away from facing burst swimming, dams should change their operations. He said last week Seton Dam near Lillooet has altered its flows and now researchers will check how it affects the run.