BRC-BIO: Estuarine food web responses to urbanization and restoration

About This Grant

Oyster reefs are critical habitats that serve as nursery grounds for economically important species while also providing key ecosystem services such as sediment trapping, water filtration, and reduction of coastal erosion. Yet, oyster reefs have declined by over 85% globally in recent years. Given the urgent need to protect and re-establish oyster reefs, a better understanding of the response of these food webs to urbanization threats and restoration efforts is needed. This research will assess the relative importance of predatory crabs in the food webs of restored versus degraded oyster reef habitats. The results of this research will provide insights into the resilience of coastal systems and should inform future restoration. This project features graduate and undergraduate student training, and the development of an immersive course-based undergraduate research experience (CURE) where students gain training in field ecology, data visualization, and science communication. Findings from this research will be shared through academic publications, public outreach activities, and student training programs to maximize impact. This project is co-funded by the Biological Oceanography Program, Population and Community Ecology in the Division of Environmental Biology, and the Historically Black Colleges and Universities Undergraduate Program (HBCU-UP), which provides awards to strengthen STEM undergraduate education and research at HBCUs. Ecological communities are comprised of many species in complex webs of interactions. These interactions may vary among environments that differ in thermal regime and across an environmental gradient of increasing urbanization. This project connects three aims to determine how warming and urbanization interact with each other and with body size of crab predators to affect a shift in crab diet with cascading effects to the trophic, and overall community, structures of oyster reefs in estuarine habitats. First, mesocosm experiments will be used to test the hypothesis that temperature and crab body size interact to induce a shift in crab diets. A second hypothesis will test the strength of predation by crabs in situ using manipulative caging experiments across 8 paired urbanized and rural oyster reefs in the Chesapeake Bay to evaluate the extent to which urbanization of estuarine sites impacts community structure. The third hypothesis will test whether urbanization of estuaries induces a shift in crab diets that changes both the strength of predation and the nature of estuarine community trophic structure by comparing stable isotope ratios at 8 paired restored and degraded oyster reefs. Outcomes of tests of these three hypotheses will advance understanding of how environmental changes in temperature and land use (urbanization, habitat restoration) affect the strength of top-down control of community structure through shifts in consumer diets and how altered trophic structure may, in turn, influence ecosystem resilience differently in restored, unmanipulated or urbanized habitats. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.