Flexing mussels: does Mytilus edulis have the capactiy to overcome effects of ocean acidification?
Ocean acidification (OA) conditions have already been shown to affect a wide variety of marine organisms. Shoreline systems, including estuarine areas where most shellfish aquaculture is conducted, experience greater rates of change in water chemistry than are seen or projected in the open ocean. In some cases, differences among individuals within a given species in response to OA stressors have been found, indicating variation in the capacity to respond to OA. Thus, predicting the impacts of OA on coastal systems and species, including species used in aquaculture, remains challenging. Legacies of historic conditions may result in some species being more resilient to elevated carbon dioxide conditions, or more able to adapt to changing conditions. Although most studies focus on the average response within a species to experimental conditions, all studies show a variance in response; this variance may be due to measurement error, small differences in the local conditions of individuals, or it may reflect real differences in response among individuals, with some individuals being more robust than others to environmental stressors. "Winners" and "losers" will likely exist not only among species, but also among individuals within species. Studies are needed to determine what driving factors are resulting in different responses to OA stress seen within species, especially long term, cross-generational studies.
Padilla and her colleagues will use cross-generational experiments with the common blue mussel, Mytilus edulis, to test for its capacity to display resilience or adapt to different OA conditions. The blue mussel is one of the most extensively studied marine organisms, has been used as a model for physiology and a variety of other studies, and is an important aquaculture species in many northern areas in the Atlantic. The short generation time of the blue mussel relative to many other aquaculture species also makes it ideal for cross-generational studies of the impacts of OA conditions. The researchers will examine multiple metrics of performance at different life stages, test for tradeoffs in performance under different OA conditions, and assess the potential for M. edulis to show resilience or adapt to changing environments. The experimental design will allow Padilla and her team to determine if blue mussels in Long Island Sound have the capacity to acclimate or adapt to OA. The results of the experiments can then be used to develop management practices for wild populations and more robust aquaculture practices for blue mussels. From an aquaculture perspective, if animals from certain source populations are more resilient to OA stress, those locations could be targeted for collection of wild seed that will produce resilient mussels in aquaculture leases. Furthermore, the environmental characteristics of these advantageous site(s) could then be characterized to predict other sites that may also produce resilient mussels. Overall, the data obtained from this work could be used to enhance mussel culture, an economically important activity of growing importance in the Northeast region.