Ocean waters wash and feed Alaska’s shores and let fish swim inland, sustaining people living off rivers. When oceans change, so does life across the state.
With the Earth warming, the atmosphere gets saturated with carbon dioxide, and “just like in a carbonated soda drink, it makes the ocean more acidic,” explained Hajo Eicken, director of the International Arctic Research Center at the University of Alaska Fairbanks.
The chemistry of oceans impacts all the organisms in it. From oysters to crabs, mussels to snails, from shellfish to salmon, all are affected by ocean acidification, and all are important for subsistence, commercial and sport fishing in Alaska.
When oceans have less calcium carbonate, a snail might struggle to build its shell. For salmon, acidification adds more stress, on top of heat waves in recent years.
To understand how fast the ocean chemistry is changing and what can be done to predict and prepare for the episodes of a more acidic ocean, the lab of Claudine Hauri, a research assistant professor with the International Arctic Research Center, focuses on the chemistry of the water in the Gulf of Alaska. Graduate student Addie Norgaard joined Hauri’s lab in August and will be primarily focusing on the project.
“The goal is to study ocean acidification in the Gulf of Alaska and how changes caused by human activity — like increased freshwater levels, higher sea surface temperatures and increased atmospheric carbon dioxide — are contributing to conditions that are stressful,” Norgaard said.
Originally from California, Norgaard grew up going to the ocean, and that’s how she developed her love for science.
“The ocean is something that’s always been there,” she said. “It starts from being a kid and being really excited about the outdoors and loving the outdoors. And then when I got older, I started being interested in science and learned how important oceans are for our climate, our food and our weather patterns. I just fell in love with the ocean.”
This month, Norgaard is going on her first cruise to the Gulf of Alaska to start looking at changes in the ocean.
Studying ocean acidification
To study carbon dioxide effects on the oceans, the researchers in Hauri’s lab combine different tools that aren’t always used together, Norgaard said with excitement.
First come the shipboard measurements. Three times a year, Hauri’s lab collects measurements in the northern Gulf of Alaska and Prince William Sound. Additionally, they use the data they get from a mooring — the Gulf of Alaska ecosystem observatory that has sensors to monitor the salinity of the water, temperature and other ecosystem variables. Hauri’s lab is specifically interested in carbon dioxide and pH measurements that give them a high-resolution view of what the carbon chemistry is doing throughout the year when they are not at sea.
Lastly, the lab uses a regional ocean model, which “is basically a big three-dimensional — physical, biological and chemical — model that we’re using to kind of reproduce what has happened between 1980 and now,” Hauri explained.
To add even more ways to observe the change, the research group is developing a sensing glider that would remotely sense carbon dioxide levels, Hauri said. This is particularly important because it will give an idea about the seasonal variability of the system across a larger area.
“We can send the glider to place and at a time where and when otherwise measurements would be impossible, even during stormy weather in winter,” Hauri said.
To understand ocean acidification, researchers need years or even decades of data. After one year, they can get a better understanding of the natural components of the system, but to see how quickly the ocean is changing, it’s not enough, Hauri said.
“It’s kind of like climate change, ” Hauri said. “Sometimes, if you look at a few years, you’re like, ‘Oh, it has gotten colder.’ But if you actually look at the mean over a very long time series, you realize that the world is warming. That’s exactly the same in the ocean.”
Fortunately, back in 2008, another research group started analyzing carbon chemistry in the Gulf of Alaska, and now Hauri’s group is continuing that research.
The data from other places help too. Since ocean acidification is happening all over the world, measurements from places like Hawaii and Bermudas give researchers an idea about the approximate rate of change in the long term. But, as it usually goes, Alaska is unique.
“In the Gulf of Alaska, you have huge natural variability,” Hauri said. “That’s why you just need a very, very long-time series to be sure that what you’re measuring has to do with the long-term trends, with ocean acidification, rather than with large variability.”
On top of this, organisms living in Alaska waters face issues just “because we are so far north, and the waters are so cold,” Hauri said.
“Naturally, we are already closer to thresholds that are harmful to organisms, just because carbon dioxide is more soluble in cold waters,” Hauri said. “We are already closer to a habitat that’s not suitable anymore.”
As the ocean surface gets fresher from glacier melt, acidification then also becomes more severe, putting aquatic organisms into a vulnerable position, Eicken added.
“There are also these so-called ocean heatwaves in the Gulf of Alaska and the Bering Sea in recent years,” he added. “Those can already stress out some of the animals such as the salmon. Then, on top of that, you put an ocean that’s more acidic — that can add additional stress.”
The University of Alaska is able to focus on the emerging problem of ocean acidification because the late Roger Markle invested $2.1 million in the UAF International Arctic Research Center to fund climate change research that makes a difference in the lives of Alaskans.
Eicken said that the research center uses the funds ”to support small teams of researchers working on pressing problems.” He explained that while federal grants usually focus on larger-scale issues, gifts such as the Roger Markle Endowment give the university flexibility to quickly “address problems that emerge from within the community, at the local or regional level.”
While looking at changing permafrost and wildfire behavior are other examples of adapting to climate change in Alaska and the Interior, ocean acidification research is the first IARC project funded by the endowment.
“This endowment is already helping us tremendously to expand that sampling to just get a better idea of what’s happening across the northern Gulf of Alaska,” Hauri said.
The Gulf of Alaska is a huge territory, and getting more data will help scientists understand what is happening on a natural basis and what will happen, in terms of ocean acidification but also climate change, Hauri said.
“What will happen with stronger melt rates of glaciers? What will happen with the stronger precipitation that we’re expecting?” she said. “In order to be able to make predictions, you need to understand what’s going on right now.”