Washington, Aug 25 (IANS): Do not make the fish run, especially if they are female. Researchers have found that sockeye salmon that are forced to rush to their spawning grounds through fast-moving waters could be dying right after their "sprint".

Researchers at University of British Columbia (UBC) tagged the salmon with accelerometer transmitters, a new tracking device that recorded how fast fish swam and how much oxygen they consumed.

"Days after sockeye passed through extremely fast-moving water, we started to see fish dying only a short distance from their spawning grounds," said Nicholas Burnett, a lead researcher from UBC.

The fast-moving water could be natural rapids or areas downstream of man made dams which the fish must cross by "burst swimming" that is similar to sprinting for humans.

Burst swimming was seen to have a greater impact on female fish. "Our work demonstrates how important it is for salmon to have easy access around obstacles in the river," added Burnett.

The findings were published in the journal Physiology and Biochemical Zoology.