Bob Foy is the Director of the NOAA Alaska Fisheries Science Center Laboratory in Kodiak. He has spent over 20 years working on marine biological and ecological research, and currently studies the effects of OA on crab.
Q: How did you get into the field of ocean acidification and crab?
Before working with commercial crab species, my research focused on the effects of environmental variability on the physiological processes in fish. In 2007, I was lucky to join an active crab research group starting to discuss ocean acidification in the NOAA Shellfish Assessment Program with a mission to look at the abiotic and biotic factors that influence the management of crab stocks in Alaska. Researchers at the Pacific Marine Environmental Laboratory and other large ocean chemistry laboratories were publishing about the increases in anthropogenic CO2 in seawater and the potential effects on shell building organisms. We could see that in order to adequately manage crab stocks, we needed to assess the potential risks of ocean acidification on commercial crab species. We built a research team, a research program, and a CO2 dosing and experimental system in a state of the art seawater laboratory. We continue to work with colleagues at other agency laboratories and universities to broaden the response variables we measure with each experiment.
Q: What are you seeing so far?
Our initial hypotheses were that nearshore, shallower species such as red king crab would be more resilient in their physiological response to increased pCO2 because they live in a more variable environment. We found significant effects of ocean acidification conditions on red king crab such as decreased survival at embryo, larval, and juvenile stages. These effects were scaled to population level effects that may be expected in the absence of acclimation or adaptation. Studies on Tanner crab, another nearshore, shallow water species suggested that the crossover effects of exposure during oocyte development were important to consider and led to decreased survival at later life stages. Recent results from snow crab suggest that ocean acidification conditions may have limited effects on snow crab stocks which is hopeful given the commercial importance of this species.
Q: What are some of the most surprising findings you’ve discovered?
We expected that deeper species (~400 m) such as golden king crab would be resilient to increased pCO2 because deep waters in Alaska are naturally corrosive. Lower survival was found during exposure experiments where treatments included surface ambient pH, possibly providing some clues on the potential for acclimation if crab are exposed at early developmental stages. Another surprising finding has been the dominant effect of lower pH over the saturation state of calcium carbonate. Effects found for many crab species at saturation states above 1 suggest that the stress associated with decreased pH may be more important in king and Tanner crab species. Results from hemocyte and genetic response variables measured by colleagues at the NOAA Northeast Fisheries Science Center and the University of California also suggest that significant energy resources are put into maintaining cellular pH and cuticle (new shell) formation in crab.
Q: What are the challenges of working with crab?
The challenges of working with crab are many. First of all…they like to eat each other. High rates of cannibalism means that samples sizes and experimental designs require additional logistics. Most of the species we study are located hundreds of miles away, even more challenging if you consider the boat ride and numerous plane rides that are necessary before reaching Kodiak Island. Adult female crab are caught in the Bering Sea multiple days from the nearest port, packed in coolers with some wet burlap and ice packs, transported by charter or commercial airlines through Anchorage, and eventually make it to their new home. Sometimes these challenges affect our ability to run experiments or limit our experimental design. Finally, crab have long embryo development periods so assessing complete early life history effects requires multi-year projects.
Q: Based on your research, what would you tell a crab fishermen in the Bering Sea about the future?
Ocean acidification conditions have been shown to negatively affect many species of commercial crab species at various life stages. Initial experimental results and subsequent estimates of population level effects suggest that crab recruitment will eventually decrease. However, laboratory experiments are not adequate for assessing the acclimation or adaptation potential for a species to respond to an environmental stressor that is changing over time. Regardless, as ocean acidification conditions increase in Alaskan waters, crab and other marine species will need to cope physiologically. Fisheries managers will need to consider the effects of ocean acidification as well as other environmental stressors such as increased temperature to sustain fisheries.
Q: Please tell us about a memorable time in the lab or in the field
In our earliest experiments, we had few scientific staff to dedicate to ocean acidification projects and we had not yet developed a flow-through CO2 dosing system. We had a NOAA Hollings undergraduate intern working in the lab to conduct one of our first experiments and she did a great job learning about ocean acidification with us. It was quickly apparent that we were not skilled marine chemists as we tried to stabilize carbonate chemistry inside 100 small beakers. It was also apparent that manually moving 23 L carboys in and out of a walk-in experimental rooms maintained at 6 °C was not going to lead to a long term sustainable program (especially if we wanted to keep students).