Nina Bednarsek is a scientist with the Southern California Coastal Water Research Project who has recently started conducting research in Alaska. She specializes in the development of biologically relevant thresholds for interpreting ocean acidification data.
Q: What element of OA do you work on in Alaska and where?
My involvement with the OA work in Alaska started after receiving North Pacific Research Board (NPRB) reward to investigate the extent of biological effect due to ocean acidification in the Gulf of Alaska and the Bering Sea. This rewards builds on almost a decade-long research on the impacts of ocean acidification on pteropods (sea butterfly), tiny shelled zooplankton that is a keystone species because it represents an important food diet for Pacific salmon, especially for pink and chum salmon in Alaskan waters.
Q: What drew you to this type of work?
I have started my research in the polar regions off the Antarctic and remained fascinated with this environment ever since. Short food chains in the polar regions are especially vulnerable to climate change and pteropods are one of the best indicator species to study how future food webs will be affected by climate change and acidification. The work I am involved with is important because it stretches all the way to human dimensions, pointing towards the vulnerabilities and adaptation strategies that Alaskan communities will undergo in the near-future.
Q: Recently you’ve been studying pteropods in the Gulf of Alaska. Could you tell us more about it?
My research in the Gulf of Alaska involves analyzing how pteropods respond to ocean acidification, mostly by looking at the extent of pteropod shells to be dissolving under corrosive OA conditions. But my focus is also to try to find genetic evidence of pteropod resilience and determine if there will be enough genetic diversity for pteropods to persist in the Gulf despite progressing ocean acidification. If we know how pteropod will respond in the future, we will have much better understanding of potential impacts on fish as well.
Q: Why are pteropods important to understand and what have you learned so far?
When exposed to ocean acidification, pteropod shells start to dissolve very quickly, with very characteristic pitting and shell corrosion patterns. From the extent of the observed patterns, it is relatively easy to determine to what level of corrosive conditions they have been exposed to and how this will impact their health and the health of the surrounding ecological community. In that sense, they are one of the most sensitive indicators for ocean acidification we know of so far, allowing us to make solid predictions about their population sustainability in the future and how this will affect salmon that heavily relies on pteropods as a food source. My initial results show that pteropods are especially compromised in the coastal waters in the Western part of Alaska, which is an indication that pteropods have been affected by ocean acidification there already. This is a OA hotspot where we it is expected that OA effects will first take place, so we need to pay particular attention to this region in our future efforts.
Q: If you could relay one piece of information to Alaskans about ocean acidification, what would it be?
Alaskan waters are rapidly changing due to climate change and ocean acidification. Over time it is going to be the effects of multiple stressors, including temperature, acidification and freshening of the coastal waters, that will restructure ocean food webs and fisheries in the future to which Alaskan communities will have to adapt. However, Alaska scientists are strong leaders in the study of vulnerability of Alaskan fisheries to these stressors. This experience will provide an excellent foundation for future resource-based climate studies, and an advice to other high-latitudinal nations with similarly vulnerable resources.
Q: Please tell us about one of your most memorable experiences in the field or in the lab.
I still clearly remember the day in the lab when I started to analyze the samples from the Southern Ocean, only to discover massive pteropod shell dissolution and be completely shocked at the realization that ocean acidification is not something that will happen in the future, but is happening here and now. I got another déjà vu moment when I was analyzing the samples collected along the US West Coast beginning in 2011, and also Alaskan waters. However, given that pteropod shell dissolution was less severe in Alaskan waters than in the other areas studied indicates that the impacted areas to date in Alaska are probably more localized, providing some suitable habitat for the rich Alaskan life now and hopefully in the future.