Another year, another record breaking run of sockeye salmon in Bristol Bay. Last year’s run of 67.7 million fish was a record and a rallying cry to protect this watershed. As of July 21, more than 76 million fish returned to Bristol Bay and its tributaries.
The run is so large that reports are coming that boats and fishing gear are literally sinking due to an overwhelming amount of sockeye salmon. And before people wonder about the sustainability of such seemingly gluttonous catches, fishermen cannot harvest salmon until their respective escapement goals have been met–i.e. enough fish have made it upriver to successfully spawn.
“After a record-breaking season like this year, there’s no question that Bristol Bay is an exceptional place that deserves exceptional protection,” said Elizabeth Herendeen of Businesses for Bristol Bay. “It’s an economic engine that pumps out billions of dollars of annual revenue, supports more than 15,000 renewable fishing jobs, and supplies millions of pounds of nutritious wild protein. That’s why businesses around the country are calling on the EPA to finalize Clean Water Act protections for Bristol Bay by the end of this year; it’s a national treasure that we can’t afford to lose.”
However, other salmon runs throughout Alaska and Bristol Bay are not seeing the same productivity. Bristol Bay’s Chinook and coho runs are experiencing comparatively poor runs, and some tributaries in Alaska are seeing record-low runs on the verge of collapse. The Yukon River Chinook run in one of them, where “the drainage-wide run may be under 50,000 fish, which is so small that escapement goals may not be met in any tributaries.”
So, what is causing the boom for Bristol Bay sockeye and the bust for other runs? Well, it’s complicated and multi-faceted. Dr. Daniel Schindler is a fisheries science professor at the University of Washington and has spent extensive time in Bristol Bay studying sockeye. He shared his thoughts with KYUK, a news source for Alaska’s Yukon Delta. Schindler offered several insights to what may be contributing to the up and down runs, but the exact scientific explanations will be difficult to pinpoint.
“What we have is correlations,” said Schindler. “And the correlations are that when we’ve had really warm—too hot, even—eastern Bering Sea sea surface temperatures, Bristol Bay sockeye have done really well. And other species in the region haven’t.” The different behaviors and life histories of these different species “are making chinook and chums vulnerable to something that sockeye aren’t–at least sockeye that are returning to Bristol Bay.”
Another aspect that may be contributing to the stellar sockeye runs in Bristol Bay is the water conditions at the rearing lakes. As they become warmer, plankton production increases in these lakes increase which has direct impacts for juvenile sockeye. “So over the last 60 years, we actually see that juvenile sockeye are growing much faster now than they were 30 or 40 years ago, which means they’re leaving for the ocean as bigger smolts. And presumably, that has something to do with their higher survival rates in the ocean.”
It’s a bitter-sweet reminder that climate change will produce winners and losers for fisheries around the world. The communities of Bristol Bay are no doubt greatly benefiting from thew booming sockeye runs. But fishermen targeting Chinook in the Yukon drainage may not even be allowed to fish this season, because of historically poor runs. In the near future, climate and fisheries science will become more and more important. But in the meantime, protecting these wild places, ensuring our fisheries remain abundant and sustainable, and keeping these watersheds intact is the best insurance policy we have to the variable impacts of climate change.