Outwelling of Dissolved Organic Carbon from Salt Marshes

Florida Agricultural And Mechanical University, Tallahassee FL

Investigators

Abstract

Although ocean margins cover only 5% of the ocean surface, they play a disproportionate role in ocean productivity. Of particular interest is the 14,500 km2 of estuarine wetlands that border the Gulf of Mexico, about 2/3 of which are intertidal salt marshes. Very little is known about the magnitude and fate of organic matter that originates in coastal marshes and enters the coastal ocean. While "outwelling," or flux of organic carbon from land to sea, of significant amounts of organic carbon was hypothesized over 25 years ago, little progress has been made in quantifying this potentially significant source. In this study, researchers at Florida A&M University will continue their research to combine discrete biogeochemical and hydrologic measurements together with modeling to quantify salt marsh derived dissolved organic carbon flux to offshore Gulf of Mexico waters. Results from this study will provide the first quantitative estimates of dissolved organic carbon outwelling fluxes from salt marshes, resulting in a better understanding of the coupled terrestrial and oceanic carbon cycle. Broader Impacts: As intertidal environments have declined rapidly over the past century due to human pressures, ever-smaller quantities of terrestrial organic matter are available for the formation and export of dissolved organic carbon to the ocean. Results from this research will provide the data to accurately evaluate the importance of these intertidal ecosystems, and help to inform policy on conserving these habitats. In addition, this project will provide a broad range of interdisciplinary learning opportunities for a diversity of students in middle through graduate school. The researchers will collaborate with COSEE-Florida, COSEE-New England, and Watershed-Integrated Sciences Partnership (GK12) programs to conduct outreach to the community.