Cooperative Ecosystem Studies Unit, Gulf Coast CESU

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This CESU solicitation is offering a funding opportunity to a CESU partner for research to develop exactly dated chronologies from the shells of Serripes groenlandicus and Nuculana radiata as indicators of benthic production for comparisons with potential environmental drivers, including sea ice. The decline of Arctic sea ice is predicted to promote an ecosystem shift from benthic-dominated to pelagic-dominated communities on Arctic shelves, raising concern for species like walrus and eiders that feed on benthic organisms. Sea ice dynamics are thought to support a rich benthic ecosystem by promoting the export of surface primary production to the ocean floor. As sea ice extent diminishes, more prolonged open-water phytoplankton blooms and increased zooplankton grazing may increasingly route surface primary production to pelagic consumers. The pace of declining benthic production has been difficult to quantify, leaving resource managers with much uncertainty. To relate annually resolved growth increments in benthic bivalves with satellite derived sea ice records to develop a predictive relationship between sea ice and benthic production. Bivalves are a key prey item for both walrus and eiders. The relative contributions of sea ice algae and phytoplankton, the two major sources of surface primary production, will also be described for bivalves using stable isotope analysis. Changes in bivalve size will be converted to differences in caloric content available to predators. Combining these products with model projections of future sea ice cover will allow to predict the pace of community shifts, clarify the underlying mechanism, and provide an early warning system for DOI managed species that rely on benthic habitats.

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