EVALUATING RESPONSE OF LARGE-SCALE SHALLOW MARINE BIODIVERSITY PATTERN TO CLIMATE CHANGE USING MICROPALEONTOLOGICAL RECORDS

Modern climate change is believed to be one of the greatest threats to marine ecosystems, however, it is difficult to assess the long-term impacts on large scale, shallow marine biodiversity patterns without isolating local human impacts. In our study, we use ostracode microfossils as a model system for evaluating modern ecosystem diversity and assessing the impacts of climate change on large-scale biodiversity pattern during the geologic past. Based on our modern equator-to-pole ostracode dataset, which covers 558 sites and >150,000 specimens in the western North Atlantic and Arctic Oceans, we observed a diversity gradient with a maximum in tropics and decreasing diversity towards the Arctic. We also compared the modern diversity patterns to those during past interglacial periods in the Pliocene (5.33-2.58 Ma) and the Pleistocene Marine Isotope Stage 5 (125,000 yrs ago), using fossil ostracode assemblages. Results suggest that Pliocene and Pleistocene climate changes affected large-scale biodiversity patterns in the North Atlantic Ocean, including geographic shifts in the location of diversity maxima.