NSERC grants at Laurentian University Subventions du CRSNG `a l ...

27Mery Martinez GarciaPhysiological bases of hypoxia tolerance in fish: The role ofphenotypic plasticity in patterns of intraspecific andinterdemic variationA grant of $23,304 per year.Une subvention de 23 304 $ par année.Discovery Grant – Subvention à la découvertePeriods of low dissolved oxygen, or hypoxia, are found in a great variety ofaquatic environments. Due to human activities, hypoxic episodes have increasedin recent years in area, duration and frequency in coastal regions, lakesand wetlands. Fish develop different strategies and mechanisms to survivehypoxia, including adjustment in behaviour, physiology and biochemistry.It is currently difficult to make generalisations on physiological responsesto hypoxia because of the widely different environments that are consideredand the plasticity of the response. My research program aims to develop predictivemodels regarding fish adaptive mechanisms to low dissolved oxygen.More specifically, I propose to conduct a cross-species field and laboratorystudy from fish in Northern Ontario to determine whether different fish speciesliving in a single environment subject to periodic hypoxia share commonmetabolic adaptations and what is the plasticity of this response. Second,using an African species as a model, I will determine experimentally whetherdifferences in metabolic responses of fish exist between populations fromnormoxic versus hypoxic habitats, and to what degree any difference is aconsequence of phenotypic plasticity versus genetic differentiation. Finally, Ipropose to conduct an experiment on the effects of hypoxia at egg and larvalstages of a single fish species from Northern Ontario in order to establish thedegree of phenotypic plasticity of fish during early development.This entire research will increase our understanding of hypoxia toleranceon a global level as well as the underlying physiological mechanisms. In thelong term, it will also increase our understanding of the detrimental effectsof hypoxia in all aquatic habitats. As a result, this research will be invaluableto aquatic biologists and environmental scientists. Once we understand theindividual responses to hypoxia, and the plasticity of these responses, we willbe in a better position to assess negative impacts of hypoxia and potentiallycontrol the biological impacts of hypoxia in aquatic ecosystems.