Oxbow lakes, off-river coves, quarries and other backwater environments are common along the floodplain of many tidal rivers, and provide the accommodation space necessary for significant amounts of fine-grained storage. This process-based study will quantitatively evaluate the manner in which these tidal floodplain waterbodies infill. The project is motivated by the important role these environments play in the storage of sediments and associated contaminants, and the broad significance of these understudied systems to local ecosystems and human populations. The overarching goals of this study are to: 1) quantify the dominant processes governing the timing and magnitude of transport and trapping within tidal floodplain waterbodies; 2) evaluate the role these environments play in the storage of a river?s fine grained sedimentary budget; and 3) assess how sediment and associated contaminant storage rates vary in response to land-use changes, industrial development, and tidal influence. The lower reach of the Connecticut River exemplifies a tidal river with prominent tidal floodplain waterbodies and will serve as our field site. Our research approach combines water column observations, numerical model simulations, and an extensive coring campaign, and is designed to encompass all of the primary spatial and temporal scales necessary to constrain fine-grained trapping and storage.
Similar to low-lying coastlines around the world, the east coast of the U.S. is rich with tidal rivers and fringing tidal settings. This project will gain essential information on how sediment and associated heavy metal contaminants are distributed within these tidal environments. The study has additional significance in that our field site (the Connecticut River), is the largest river system in the northeast, one of only 14 American Heritage Rivers designated by the U.S. EPA, among only 26 U.S. wetlands recognized for international significance by the United Nations, and among 40 of the ?Last Great Places? in the Western Hemisphere designated by The Nature Conservancy. Educational outreach includes undergraduate presentations to high school classes, and the opportunity for high school seniors to work with the research team over a six-week internship in the summer. We will train one Ph.D. student with funding from this project.