Salmon escapes 'help ecosystem'

Photo / Thinkstock
Photo / Thinkstock

Allowing more Pacific salmon to escape from fishing nets could benefit both humans and bears, a US study has found.

Greater "escapement" would increase the number of salmon spawning in coastal streams. This in turn would benefit the environment and lead to more salmon in the sea, say researchers.

Salmon fisheries in the northwest Pacific are carefully managed to strike a balance between how many fish are harvested and how many allowed to spawn. But there is concern that too many salmon are being caught, causing the ecosystem to suffer.

"Salmon are an essential resource that propagates through not only marine but also creek and terrestrial food webs," said study leader Taal Levi, from the University of California at Santa Cruz.

Levi's team focused on salmon populations and 18 grizzly bear populations in British Columbia, Canada.

When salmon are plentiful, bears eat less of each fish, discarding the left-overs which enter the ecosystem and enrich the waters downstream. This provides a better environment for growing salmon.

The researchers found in most cases allowing more salmon to spawn not only helped bears but also led to more salmon in the oceans.

The research is published in the online journal Public Library of Science Biology.


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