In this project, the principal investigator will study greenhouse gas (GHGs) emissions from coastal invertebrates in relation to nitrogen availability and temperature.
Coastal ecosystems may be significant sources of greenhouse gases, including nitrous oxide (N2O) and methane (CH4) that have 300 and 25 times the global warming potential per molecule of carbon dioxide (CO2). Marine invertebrates, in particular, may produce GHGs in coastal ecosystems either directly or indirectly, through biogenic alteration of sediments, which expands the oxicanoxic interfaces in which microbes thrive. Anthropogenic nitrogen (N) loading and warming of coastal oceans may both enhance GHG production significantly. To test the hypothesis that numerically dominant coastal invertebrates, including a tube-building amphipod (Ampelisca abdita) and bivalves (Mytilus edulis, Mercenaria mercenaria, Geukensia demissa), can emit significant quantities of CO2, N2O , CH4, manipulative experiments will be performed. Potential emissions from each species, and subpopulations (along an existing nitrogen gradient in Narragansett Bay, RI), will be assayed under standardized conditions. To test how emissions from coastal invertebrates vary in response to anthropogenic fertilization and warming of the ocean, nitrogen and temperature will then be manipulated in mesocosm experiments. Fluxes and dissolved GHG concentrations will be compared across treatments. The abundance of two key potential mediators of GHG fluxes, ammonia-oxidizing and methane-oxidizing microbes, will also be characterized. These examinations will reveal functional consequences of ocean warming and fertilization, including the potential of coastal organisms to enhance global climatic feedbacks.
The broader impacts involve broadening participation of under-represented groups in STEM. The principal investigator is committed to advancing science among all members of our diverse society. A graduate student will be recruited from a national diversity outreach program. Undergraduate researchers, via Summer Undergraduate Research Fellowships, will be mentored, and their contributions will be featured in new workshops that will be developed for high school students and teachers, and the National Society for the Advancement of Chicanos and Native Americans in Science.
This project is supported under the NSF Ocean Sciences Research Initiation Grant (OCE-RIG) program, with goals to support novel research by early career scientists and increase the diversity of the U.S. ocean sciences workforce and research community. With OCE-RIG support, this project will enable a promising early career researcher to establish themselves in an independent research career related to ocean sciences and broaden participation of under-represented groups in the ocean sciences.
