Adaptive potential for changes in environmental conditions in exploited fish species.

Global change is threatening life at the seas by changing the physical, chemical, and biological conditions of the environment. Thus, marine species will need to adapt to the new environmental conditions to thrive. This adaptation depends on the genetic variation within species, as it is the raw material on which natural selection works. Because environmental conditions at the sea are heterogeneous and most marine species are distributed across these diverse marine environments, it is likely that the genetic variation making possible the adaptation to changes in the environment is currently present within populations. Thus, the genetic flow among populations (or environments) can be one of the most important factors enabling adaptation to future environmental conditions in fish. However, harvesting fish populations is likely eroding their capacity to adapt to changes in the environment where they live. Thus, the goal of this study is to quantify the adaptive potential and likelihood of adaptation to environmental change in exploited fish populations, contributing with clear transferable knowledge to fisheries management strategies towards long-term sustainability. To do this we will use neutral and functional genetic variation data of two fish species from different environments presenting different degrees of exploitation. Potentially adaptive genetic variation will be revealed by looking for signals of both, adaptive and balancing selection among environments. Then, we will quantify the amount of potentially adaptive genetic variation and the effect of harvesting on it. Finally, we will investigate the strength of selection to get a likelihood of adaptation to future environmental change. Overall, the expected results of this study will set up theoretical and methodological frameworks for the evaluation of the current levels of adaptive potential for future environmental change in exploited fisheries.