Diversity is the Strength of Bristol Bay’s Sockeye Run

A University of Washington professor who has spent years researching the Bristol Bay watershed in Southwest Alaska says it’s important to maintain the diversity of the waters contributing to the world’s largest sockeye salmon run.

The river systems flowing into the watershed compensate for each other, much like a diversified investment portfolio, Daniel Schindler told the Matanuska-Susitna Salmon Science and Conservation Symposium in Palmer, Alaska, on Nov. 17.

Within that watershed, habitat variation is important down to the very small scales, with each set of habitat having its own features, Schindler told biologists, conservationists, and commercial, sport and subsistence harvesters attending the symposium.

Schindler is a principal investigator of the university’s Alaska Salmon Program, which has studied Pacific salmon, their ecosystems and their fisheries in western Alaska since the 1940s. The program’s current research is focused on understanding how watersheds function in areas ranging from processing nutrients and carbon to how geomorphic attributes of watersheds regulate these ecosystem processes and services.

“We can do a lot of tangible things now to protect ecosystems, to make ecosystems resilient to climate change,” he said. “Protecting habitat networks is a way to build climate resilience. Stability and productivity of fishery systems is derived from diverse and changing habitat.”

In the some 130 years that people have fished commercially in Bristol Bay, that fishery has been sustainable because the commercial fishery interacts with a sustainable population, because individual rivers compensate for each other, he said.

Climate change notwithstanding, the fishery remains resilient because each river within the watershed is genetically distinct, down to the smaller rivers and tiny streams, he said. Removing some of those streams would weaken the strength of that diversity, he said.

The US Environmental Protection Agency has expressed concern that the proposed Pebble copper, gold and molybdenum mine in the area of the Bristol Bay watershed could result in potential loss of 1,100 or more acres of wetlands, lakes and ponds that connect with streams and tributaries of those streams where salmon are documented.

Final decisions regarding the permitting of that mine are still pending.