Adaptive responses of an aquatic vertebrate to chemical pollution

Human-induced pollution features among the greatest challenges that organisms face for survival and adaptation. Aquatic ecosystems have been exposed worldwide to varying degrees of pollution, and the fitness of their communities and populations has been affected to such extent that biodiversity is compromised. We evaluate the potential adaptive response of three-spined stickleback, a model fish, to pollution after multigenerational exposure to mercury and PCB. Both chemicals feature among the most toxic pollutants that bio-accumulate in the food chain. Our first aim will be to test if exposure to metal or PCB pollution in situ has led to divergent phenotypes and genetic backgrounds. The second aim will be to test in the lab and in near-field conditions if pollutant adapted populations exposed to the original or other stressors are more resistant than naive populations. This is of importance considering the future challenges populations are facing. Our approach is unique, because it involves a real scenario of field adapted individuals and because the effects resulting from exposure to pollutants are tested over multiple generations across the full genome and at multiple levels of biological organisation from cell to population. Our findings provide novel interdisciplinary fundamental knowledge on ecotoxicology, physiology and genetics, and benefit the assessment, monitoring and follow-up of a Good Ecological Status of the European aquatic environment.