We know directly the negative impacts that a warming ocean has on salmon all across Alaska. But what about the other big threat – increased acidity?

Extensive studies for years have been underway by Alaska scientists on impacts to major fish and shellfish stocks. But for Alaska salmon, only two studies have been done, both out of state.

That’s changing with a federally funded, multi-year, collaborative project underway with Alaska’s universities and the Alaska Ocean Observing System.

 “We don’t really have concrete evidence that it’s already affecting our fisheries. But what is certainly affecting our fisheries is temperature in the Gulf of Alaska, as well as in the Bering Sea, and what those temperature changes have done to our fishery stocks is certainly under investigation right now and we’re learning more and more about it. But the ocean acidification is certainly a larger, further down the line risk that’s going to compound with all the other changes that are currently occurring. It is certainly a risk we want to look at ahead of time.”  

Toby Schwoerer is an economist with the Institute of Social and Economic Research at UAA/Anchorage.

He’s part of a team that is formally evaluating the risks of ocean acidity to Gulf of Alaska salmon, and assessing responses that will be needed to plan and adapt.

 “Because it’s important for us to be prepared. The better we can prepare for ocean change, the better we’re going to end up managing our resources which are going to need to adapt to that rapid ocean change. We need to take advantage of the great gene pools that we have to adapt to the rapid changes, but we need to do it in a way that allows the resource to adapt, and allows not only the resource to adapt, but also allows our salmon management system, the human dimensions of our fisheries, to adapt to this and be part of the solution, which means mitigation, and I can’t stress this more.”

Studies elsewhere have shown that acidity impairs coho salmon’s sense of smell and slows pink salmon growth rates. Other impacts remain unknown. Schwoerer says new findings could eventually change the way that Alaska salmon fishermen fish.

 “We know we are having some of the best management practices in the world. But the question is, will they be the best management practices in the future? That’s the big question that we want to raise.”

He points out that Alaska’s salmon fleets are contributing to the problem. Increased acidity stems from ocean absorption of carbon dioxide emissions caused primarily by burning of fossil fuels. In the race for fish, average horsepower throughout the entire salmon fleet has doubled.