Speaker/Affiliation: Ciara Willis, Monterey Bay Aquarium Research Institute (MBARI)
Title: Marine Predators as Archives of Earth System Change
When: Wednesday, February 11 12:00pm PST
Location: EMS B214
Abstract: Predators integrate variability across space and time, effectively averaging the flow of nutrients and energy from the physical environment through food webs. As a result, archival samples of predator tissues (such as bones or scales) provide a valuable record of past conditions, capturing environmental change alongside shifts in food webs that support species of commercial, ecological, and cultural importance.Compound-specific stable isotope analysis of carbon and nitrogen offers a powerful framework for interpreting these archives, allowing us to disentangle changes in the physical environment, biogeochemical cycling at the base of the food web, and trophic structure. In this talk, I highlight a century-long archive of haddock scales and otoliths from Georges Bank in the northwest Atlantic, collected by the National Marine Fisheries Service. Using amino acid–specific isotope approaches, this record reveals long-term warming and “tropicalization” of the regional ocean system over the 20th century, followed by an abrupt shift in the early 2000s toward strong influence from Arctic freshwater inputs.Together, these results demonstrate how molecular isotope tools applied to historical biological archives can illuminate changing oceanographic regimes and their propagation through ecosystems, offering a multi-faceted lens on climate-driven change that bridges physical oceanography, biogeochemistry, and marine ecology.
