The wetland boundary between terrestrial and coastal ocean environments is a dynamic and highly productive zone, but its role in biogeochemical cycling and ocean productivity is not well understood.

Dittmar et al. (2006) estimate that >10% of the terrestrial DOC fluxes to the world oceans are derived from mangrove wetlands alone.

Material exchange with marshes and groundwater are two key sources for carbon to the coastal ocean.

Along the northern Gulf of Mexico coast, prolific point and non-point sources of carbon and nitrogen exist in the form of major rivers and expansive wetland ecosystems that extend from Florida to Texas.

Most notably, the Mississippi River and its associated deltaic estuaries have been linked to carbon and nitrogen storage and offshore transfer of energy.

Relative sea level rise due to subsidence and eustatic changes in sea level has enhanced coastal wetland destruction. Inundation frequency and duration of marsh water levels as sea level rises will have a strong impact on the net retention or release of C, N and P in accreted organic matter.

Extended low water or dry periods in a marsh can lead to a net export of nutrients and a loss of carbon.

Rapid wetland loss due to rising sea levels combined with landscape-scale hydrologic alterations indicate these buried carbon repositories (marshes) may be vulnerable to remineralization processes and ultimately contribute to ocean-atmosphere carbon pools.