Q: You work on groundfish response to OA, among other things. What are the main takeaways that you’ve learned so far?
One of the main takeaways from my own work and from that of colleagues is that the response to OA is more varied than we initially thought it might be. We are finding that even closely related species can differ in their sensitivity. For example, Pacific cod and walleye pollock are closely related, but we saw effects of OA on growth of larval Pacific cod that were not apparent in walleye pollock.
The other lesson we learned is that you need to take a pretty broad approach to evaluating the sensitivity of a given species. This may involve repeating experiments to confirm results or look for different types of effects. As I said, while our early studies did not find effects on growth of walleye pollock larvae, more recent follow-up studies suggest impacts on lipid metabolism and development which could have negative impacts later in life.
Q: How do you go about setting up experiments to measure OA responses in groundfish? Are there factors that make it particularly tricky?
Now that we have a number of experiments under our belt, the technical aspects of running the experiments go a little more smoothly each time. But the difficult part that persists is deciding exactly what types of responses we are going to measure in each experiment. We always measure factors like growth rates, but then we have to choose among other factors like evaluating developmental deformities, metabolic processes, behavioral and sensory biology, and even genetics. Each of these aspects costs money and requires partnering with different experts. We have to balance applying all these tools to a single species or even a single life stage with gathering some information for the range of species that we are interested in. In making these decisions we try to provide the greatest overall understanding of the impacts of OA on Alaska and Arctic ecosystems and fisheries. We also set aside samples from the experiments, so that we can go back later to examine things that weren’t included in the first set of analyses.
Q: The lab and the wild are vastly different environments. How do you approach this when running experiments and interpreting results?
Yes, that is a great question and something that we think about a lot. We generally think of the lab as being a pretty good environment for fish to grow up because there is plenty of food and there aren’t any predators around. But, there are other differences between the lab and the ocean whose impacts on our observations are harder to evaluate. While there is plenty of food available to the fish in the lab, it isn’t exactly the same as they would find in nature. In the lab we have the ability to focus on one or two factors at a time while controlling other things that might vary in the field. When we interpret our observations and apply them to fishes in the wild, we want to focus on the most fundamental aspects of the responses that we can be confident will be robust to those differences. So we accept that the fish might not grow at the same rates in the lab as in the field, but if we see that exposure to high CO2 levels in the lab affects growth rates, we can be pretty confident that the same basic response would occur in the wild.
Q: What led you to the field of OA and groundfish?
Most of my work since graduate school has focused on environmental and habitat effects on fishes with an emphasis on temperature effects. In the early to mid-2000s, the idea emerged that ocean acidification was something that biologists needed to pay attention to, not just the ocean chemists. The lab where I worked (and now lead) has great facilities for doing the exact kind of experiments that were needed to study the issue for Alaska fishes (clean seawater and chilling capacity for cold-water experiments). So, in collaboration with others from across the Alaska Fisheries Science Center, we drafted a broad OA research plan and formed collaborations with chemists at the University of Alaska and NOAA’s Pacific Marine Environmental Laboratory. We did our first experiments in my lab in 2009 with some support from the Pollock Conservation Cooperative Research Center, and we have been working on it ever since, now with funding from NOAA.
Q: Do you have any particularly memorable moments from the lab or in the field?
My work on OA has all been based in the laboratory, and my favorite moments almost all involve the graduate students and undergraduate interns that I have worked with over the years. They frequently come in with an understanding of what OA is, but not how we study it. It is great to see them figure out how their summer project fits into the big picture and our growing understanding of this world-wide concern.
Q: Do you have hope for groundfish in the future in our changing climate?
I believe there is always reason for optimism. The recent declines of Pacific cod in the Gulf should definitely serve as an indication of the potential sensitivity of some of our critical fisheries to changing climate conditions. But, Alaska’s oceans are extremely productive systems that have supported fisheries and communities for generations. The key will be continuing to monitor ocean conditions and fish stocks while improving our understanding of climate impacts, and incorporating these into our robust management practices so we can adapt to changing conditions. I am confident that we can do that. So, yes, I am optimistic about the future of groundfish populations and the fisheries and people they support.