Gussenhoven Lecture: Elizabeth Canuel, Virginia Institute of Marine Sciences (VIMS)

UNC Marine Sciences’ is proud to host Dr. Elizabeth Canuel as the Gussenhoven sponsored lecturer.

Presenter Affiliation: Virginia Institute of Marine Sciences (VIMS)

Title: Ecosystems on the Edge: Carbon Composition and Dynamics at the Marsh-Estuary Interface

Abstract: Recent studies have advanced our understanding of major terms in the carbon budget of the coastal ocean, including riverine input to estuaries, exchange between the major aquatic reservoirs, sediment burial, air-sea exchange, primary production and respiration. However, gaps remain in quantifying carbon fluxes and associated uncertainties at key interfaces in the coastal zone such as the marsh-estuary interface. This presentation will highlight an ongoing study that is measuring the amounts, sources, and composition of dissolved and particulate organic carbon exchanged at the marsh-estuarine interface of a representative temperate system, Taskinas Creek, VA. Water samples were collected over a tidal cycle on a monthly basis from Taskinas Creek over ~2 years, to determine the concentrations and sources of carbon pools over a range of timescales (e.g., tidal, monthly, seasonal). Concentrations of three carbon pools were determined: particulate organic carbon (POC), dissolved organic carbon (DOC), and dissolved inorganic carbon (DIC). Sources of POC were determined using lipid biomarker compounds (fatty acids and n-alkanes), stable isotopes, and C:N ratios, while optical properties and C:N ratios were used to study the source, composition, and degradation state of DOC. Results from this study demonstrate the value of high-resolution studies for estimating the role of marsh and estuarine environments as sources and sinks for carbon.