Arctic Marine Evolution: using local adaptation to infer future evolutionary responses of Calanus copepods to a changing environment

Predicting the effects of climate change on Norwegian and Arctic marine biodiversity is central for a sustainable conservation of productive national marine resources. Increasingly, however, scientists are recognizing that model predictions of the effects of future climate change on organisms must include accurate estimations of their capacity (or lack thereof) to acclimatize or adapt to the predicted changes over time. The EvoCal project will determine the capacity of the copepod Calanus glacialis, a key species in the pelagic food web of the Arctic, to track future environmental change via acclimatization (reversible, short-term changes in physiology) and evolutionary adaptation (changes in the genetic composition of a population over time). To do this, we will compare the environmental tolerance ranges to temperature and pH of distinct populations along the significant environmental gradient of Norwegian coastlines, from productive temperate waters (Lurefjorden and Balsfjorden) to the ice-covered high Arctic (Billefjorden). If they have adapted their physiology to match these diverse environments in the past, a phenomenon called local adaptation, they may be more likely to adapt and survive in the face of future environmental change. We will 1) employ hydrographic moorings to characterize the variability and diversity of environments that Calanus experiences throughout its range in Norwegian waters and link that to its distribution, 2) use new genetic tools that have recently upended traditional Calanus distribution maps and provided increased ability to detect population genetic structure, 3) investigate intra-species, inter-population physiological variability by quantifying population-specific responses to climate-related environmental drivers: temperature and pH. Integrating these multidisciplinary tools, we will help inform better and more accurate model predictions for the future persistence of this key species in Norwegian arctic waters.

Predicting the effects of climate change on Norwegian and Arctic marine biodiversity is crucial for a sustainable conservation of productive national marine resources. Increasingly, however, scientists are recognizing that model predictions of the effects of future climate change on organisms must include accurate estimations of their capacity (or lack thereof) to acclimatize or adapt to the predicted changes over time. While difficult to quantify in real time, we can use past adaptation to environmental gradients in single species to infer their capacity to adapt to future environmental change. The EvoCal project will determine the capacity of Calanus copepods C. finmarchicus and C. glacialis, key species in the food web of the North Atlantic and the Arctic, to track future environmental change via acclimatization and adaptation. To do this, we will compare the environmental tolerance ranges to temperature, pH and salinity of distinct populations along the significant environmental gradient of Norwegian coastlines, from productive temperate waters to the ice-covered high Arctic. If they have been able to adapt their physiology to match these diverse environments in the past, a phenomenon known as local adaptation, they are likely to have the capacity to adapt to track and survive in the face of future environmental change. We will 1) employ state-of-the-art sensors to characterize the variability and diversity of environments that Calanus experiences throughout its range in Norwegian waters and link that to its distribution, 2) use new genetic tools that have recently upended traditional Calanus distribution maps and provided increased ability to detect population genetic structure, 3) investigate intra-species, inter-population physiological variability by quantifying population-specific responses to climate-related environmental drivers: temperature, pH, and salinity. If tolerance ranges vary intraspecifically, the species may be able to adapt in the future.