February 25, 2014
This is Fish Radio. I’m Laine Welch – Pink salmon could be first to feel the effects of off kilter ocean acidity levels — More after this —
The At-sea Processors Association’s Alaska pollock fishing companies fund marine research programs at Alaska’s universities to improve our understanding of the environment, and to promote conservation of our ocean resources. Learn more about APA’s conservation efforts at www.atsea.org.
Researchers are measuring the ways sea creatures are responding to hostile changes in the ocean. The biggest threat comes from off kilter carbon dioxide levels that are absorbed by the oceans, making them more acidic. Water samples collected this spring from the Gulf of Alaska show that acid levels are increasing more quickly and more severely than previously thought. The Gulf findings are similar to those seen in the Chukchi and Bering Seas.
It does seem to be more accelerated in Alaska because of the colder water temperatures. Cold water naturally holds more CO2 which controls the pH (acidity) in the water.
Jeremy Mathis is a chemical oceanographer at the University of Alaska/Fairbanks. Scientists estimate the ocean is 25 percent more acidic now than it was 300 years ago. Increased acidity robs the ocean of calcium carbonate, the building block of sea creatures’ skeletons and shells.
Crabs, corals…these animals aren’t’ going to just dissolve one day. What will happen long before that is their physiology will be affected, they’re not going to be able to grow. We‘ll have recruitment failures.
Bob Foy is director of the NOAA Fisheries Science Center at Kodiak. The increased acidity will directly affect the entire marine eco system.
What’s going to happen to animals living in this environment? Understanding the impacts on fish, marine mammals and sea birds… It’s not only going to directly impact some animals but it is going to impact the ecosystem and food webs. And that may be more important to us than we realize.
Researchers already are seeing signs of corrosion in tiny shrimp-like pteropods – which make up 45% of the diet of Alaska pink salmon. Jeremy Mathis followed by Bob Foy —
They are probably going to be one of the first organisms to be negatively impacted from this additional acidification that’s going on.
In a 10% increase in water temperature, which is what most people fear in terms of climate change, there would be about a 3% drop in mature salmon body weight. On the other hand, a 10% drop in pteropod production would lead to about a 20% drop in body weight. Obviously the system is fairly dynamic, but the loss of pteropod population would be extremely detrimental to pink salmon populations.
Alaska researchers are leading the world in ocean acidification studies. The only thing that’s certain is Alaska’s fisheries will take a hit. Jeremy Mathis —
Fish Radio is also brought to you by Ocean Beauty Seafoods, celebrating 101 years of partnership with Alaska’s coastal communities. www.oceanbeauty.com In Kodiak, I’m Laine Welch.