Scientists investigate climate change impact on fisheries


Climate Change is affecting Alaska more than any other place in the U.S.; EPA statistics indicate the state has warmed twice as fast as the rest of the country over the past 60 years. Terry Johnson, Marine Advisory Agent and professor with the university’s Alaska Sea Grant, is trying to find out how this warming could affect the state’s valuable fisheries.

Johnson was a commercial fisherman before joining the College of Fisheries and Ocean Sciences faculty and has lived in Alaska for over 35 years.

“Fish were always my passion as well as my work,” Johnson said.

On Oct. 7, people gathered in the O’Neill building and several other places around Alaska to listen to “A summary of recent research and current thinking on climate change and Alaska’s fisheries,” a seminar by Terry Johnson of the College of Fisheries & Ocean Sciences’ Marine Advisory Program in Anchorage. The web-based seminar was derived from an industry report Johnson wrote entitled “Climate Change and Alaska Fisheries” and broadcast live to an audience of community members and students from Juneau, Fairbanks, Homer and Kodiak.

Terry Quinn, a professor with the college, is coordinator for the seminar series this semester, which included Johnson’s presentation. The series is put on by the Department of Fisheries in Juneau.

“It’s a teaching tool, a research tool, and a service tool, all wrapped into one,” Quinn said.

Oceans are storage containers for man-made heat and carbon dioxide. This heat increases ocean temperature, Johnson said. Although long-term impacts of climate change have only mildly affected Alaska’s fisheries, he said, rising ocean temperatures lead to an increased frequency of storms, changes in current flows and loss of sea ice. Ocean acidification is also a problem, particularly for shellfish.

Ocean acidification occurs when carbon dioxide reacts with seawater to create acid. The acid leads to reductions in carbonate, which shellfish rely on to grow and strengthen their shells. Crab species, especially king crab in the Bearing Sea, are so threatened by ocean acidification that NOAA Fisheries predicts Alaska’s king crab fishery may collapse.

Fish stocks show a dramatic response to temperature increases, so fisheries are concerned with changes in abundance, distribution and behaviors Alaska’s stocks of salmon. Each respond differently to environmental change and researchers are unsure how well different species can adapt.

Some salmon have extended their range, making them accessible to people who couldn’t access them before. Pink and Chum Salmon production may increase if their spawning streams don’t dry up with increased global temperatures, but Chinook and Coho Salmon populations may decline, Johnson said.

Johnson said the fishing and seafood industry is “a cornerstone of the Alaska economy and of the cultural lives of residents.”

Alaska houses the nation’s largest commercial fisheries and drives an estimated $5.8 billion in economic activity. But change is underway even if we drastically revised our technology to reduce carbon emissions, so we need to develop ways to realistically adapt to climate change, rather than waiting, Johnson said.

Johnson’s presentation highlighted ways individuals and communities are trying to diversify their fisheries and mitigate risk. They can adapt and increase resilience to change by thinking creatively. They can engage in mitigate strategies such as reducing carbon emissions and conduct research and monitoring.

“It’s not a faith-based issue, it’s simply data,” Johnson said.

People who don’t believe in climate change or are unaware of the issue should review and read the data and pay closer attention to our natural world. We all have a responsibility to seek out reliable sources of information, he said.

Johnson hopes for stability, despite radical change being a more “fashionable” topic. Climate change could bring opportunity to Alaska’s fisheries, as it has to fisheries in other parts of the world, but it comes at a cost of being expensive and harmful to many people, he said.

“I’d like the industry and the public to think ahead and look for ways to maintain as much product and market stability as possible,” Johnson said.

A PDF of Johnson’s industry report Climate Change and Alaska Fisheries can be downloaded for free from the Sea Grant Alaska Bookstore’s website.

This article was corrected on Oct. 14, 2016. The article originally wrote that Terry Johnson was in the Juneau Center.  

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