Salmon forced to 'sprint' less likely to survive migration

Aug 20, 2014
Salmon forced to 'sprint' less likely to survive migration
Sockeye salmon that sprint to spawning grounds through fast-moving waters may be at risk, suggests new research by University of British Columbia scientists published in the journal Physiological and Biochemical Zoology. Credit: Nicholas J. Burnett

Sockeye salmon that sprint to spawning grounds through fast-moving waters may be at risk, suggests new research by University of British Columbia scientists.

When encounter turbulent, fast-moving water – such as rapids or areas downstream of dams – they must move upstream using a behaviour known as "burst swimming" that is similar to sprinting for humans.

"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 research biologist at UBC and lead author of the study, published in Physiological and Biochemical Zoology.

Previous UBC lab research found that burst swimming requires extra oxygen and energy, creates a build-up of stress metabolites like lactic acid in the blood, and may lead to cardiac collapse or heart attacks. This is the first study to show that excessive burst swimming can impair wild salmon and cause death later on in their migration. This phenomenon is known as 'delayed mortality'.

Researchers found that fish that chose to burst swim for long periods through the high flows downstream of a dam were more likely to die en route to their spawning grounds, after they passed through the fast flows, than those that chose to swim a bit slower. Burst swimming had a greater impact on female fish, supporting this group's research that shows female salmon are more sensitive to environmental hardships during migration.

"We now understand how this important but energetically costly swimming behaviour can impact the survival of sockeye during their upstream migration," said Burnett, who worked on this study as part of his master's research with UBC Professor Scott Hinch and Carleton University Professor Steven Cooke.

"Our work demonstrates how important it is for salmon to have easy access around obstacles in the river."

Researchers tagged fish with accelerometer transmitters, a new tracking technology that records how fast fish swim and how much oxygen they consume.

Tagged were released in the high flows downstream of a dam in southwestern British Columbia and tracked as they navigated through a fishway and two lakes to their spawning grounds.

Explore further: Dam removal improves shad spawning grounds, may boost survival rate

Related Stories

The great salmon run algorithm

Jun 24, 2014

Solving complex problems is rarely a straightforward process, there are often many variables and countless plausible solutions each one of which has its pros and cons. Mechanical engineers at the Babol University of Technology ...

Transporting juvenile salmon hinders adult migration

Dec 05, 2008

Scientists have discovered that management efforts intended to assist migrations of salmon and steelhead trout can have unintended consequences for fish populations. Juveniles that are transported downstream on boats can ...

Recommended for you

Norway plans to slash subsidies to fur farms

3 hours ago

Norwegian fur farmers denounced Tuesday a government proposal to slash financial support to the controversial industry and warned that it could lead to farm closures in vulnerable rural areas.

Hitting the borders of expansion

7 hours ago

Why does a species not adapt to an ever-wider range of conditions, gradually expanding its geographical range? In their paper published on May 5 in PNAS (Proceedings of the National Academy of Sciences), Jitka Polecho ...

Fire linked to dieback spread

8 hours ago

Fire has the potential to increase the range and severity of Phytophthora dieback in native plant communities infected with the disease, suggests a study at the Stirling Range National Park near Albany.

How mixing light with salt makes a smolt?

8 hours ago

For decades, researchers have tried to find out what regulates changes in salmon when they transform from being freshwater to saltwater fish. Now they have come a little closer to an answer.

Australia—riding on the insect's back

9 hours ago

As you may have spotted, the title of this article is a cheeky reference to the famous saying that Australia rides on the back of a particular woolly ruminant. The reference dates back to 1894, when the wool ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.