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Research biologists speak of 'jewels' of Bristol Bay

April 12th 1:51 pm | Margaret Bauman Print this article   Email this article   Create a Shortlink for this article

From the perspective of veteran University of Washington fisheries biologist Tom Quinn, there is no doubt that the wild red salmon stocks that return in abundance annually to Bristol Bay are "the jewels and crown of wild salmon"

And what makes these jewels shine is stock diversity, echoes Daniel Schindler, Quinn's colleague in fisheries research at UW.

"If one stream is a bust in one year, the predators will move to another stream and chances are that stream will do better that year," Schindler said.

It is the careful balance that stock diversity has created over thousands of years that has returned annually millions of wild salmon to Bristol Bay, a phenomenon that is the source of great concern to Quinn and Schindler, least that diversity be somehow disturbed.

Both researchers were to invited by The Nature Conservancy to speak in Anchorage in mid-April on their findings on salmon stock diversity, at the Southwest Alaska Science Forum . They spoke earlier with Alaska Newspapers about their work.

The salmon populations of the Bristol Bay region are self-sustaining and highly productive," Quinn said. "You can live off that interest forever. Future climate conditions will if anything be more favorable," he said.

But the complex of populations and the whole intact ecosystems on which they rely is such that if one piece is removed and the rest remains intact, it won't work, because the system functions based on the whole system being intact, he said.

Because various salmon populations come back at different times, predators can only actually access the salmon when they are spawning, Schindler said. "That extends the season. They sort of work their way down the cafeteria line."

Qunn and Schindler discussed their research findings in detail last summer in an article on population diversity published in the magazine Nature, speaking of the "portfolio effect" in the exploited salmon species.

"Variability in annual Bristol Bay salmon returns is 2.2 times lower than it would be if the system consisted of a single homogenous population rather than the several hundred discrete population sit currently consists of," they wrote in the paper, on which they collaborated with several other UW researchers. "Furthermore, if it were a single homogeneous population, such increased variability would lead to ten times more frequent fisheries closures. Portfolio effects are also evident in watershed food webs, where they stabilize and extend predator access to salmon resources."

Their research, the authors concluded, demonstrates the critical importance of maintaining population diversity for stabilizing ecosystem services and securing the economies and livelihoods that depend on them.

The prospect of developing a large scale copper-gold-molybdenum mine at the headwaters of the salmon spawning streams poses the likelihood of adversely affecting the balance of stock diversity, they said in interviews. Such a mine is going to change the ecosystem and Alaskans must decide what kind of trade-offs they are willing to accept, they said.

It is clear that seafood processors are concerned about the future of this valuable resource and the image that a large-scale mine could impose on the public regarding compromises related to Bristol Bay sockeye salmon, Schindler said.

The UW fisheries research program itself dates back to the 1940s, in the wake of a climate shift in the 1930s which had Washington State based canneries concerned about where all the salmon were going. To date, UW fisheries researchers have compiled six decades of information on the Bristol Bay fisheries.

What the future holds for these fisheries, is uncertain. Trying to estimate how productive salmon will be 100 years from now is an exercise in uncertainty, given the factors of climate change, they said.

It is important at this point to hedge our bets against climate change and develop management strategies that give the salmon a fighting chance, they said.

 

Margaret Bauman can be reached at mbauman@alaskanewspapers.com, or by phone at 907-348-2438

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