Impacts of deglaciation on benthic marine ecosystems in Antarctica

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Environmental changes due to ice loss and deglaciation disturbances will significantly impact Antarctic ecosystems at different levels of biological complexity and spatio-temporal scales. At the lower level of biological organization, changes in key environmental parameters, such as temperature, salinity, productivity and turbidity, may have significant effects on important fitness traits such as growth, survival and fecundity of individuals. These effects may percolate to higher levels of organization such as population and community levels. Thus, lower growth, higher mortality rates and lower fecundity may affect the demographic dynamics of local populations. In addition, at a community scale, in a stressed environment some species may become locally extinct or they may be outcompeted by stronger competitors due to a decrease in individual performance. Alternatively, pioneer species with weak competition abilities would dominate highly perturbed sites. In this way, ice loss and disturbance from deglaciation may promote changes in species diversity and community structure at different directions and spatial scales, moving communities to alternate stable states. Over a longer time scale, all these ecological effects have consequences on an evolutionary scale in determining genetic diversity and gene flow, which may reduce the evolutionary potential of species. Under this scenario, this project aims to investigate the impacts of physical disturbance arising from climate-warming induced deglaciation on benthic communities around the West Antarctic Peninsula. We adopt a multidisciplinary approach across nested scales from individual to ecosystem level, and from an ecological to evolutionary scale, evaluating genetic, physiological, population, community and ecosystem impacts of this perturbation. In addition, we use sclerochronology to develop biological proxies for reconstructing long-term and short-term environmental changes in Antarctica.