The Effects of Sea-Level Rise and Saltwater Intrusion on Wetland Nutrient Transport in the Atlantic Coastal Plain.

Human-accelerated sea-level rise is facilitating the movement of brackish water into low-lying agricultural lands across the Atlantic Coastal Plain. On the lower eastern shore of the Chesapeake Bay, saltwater intrusion (the landward movement of saltwater from the ocean) is increasing the potential for large pulses of nutrient release from cultivated lands - with devastating consequences for both agriculture and the environment.

We examine nutrient release from abandoned farm fields exposed to saltwater intrusion. Laboratory microcosm experiments are used to estimate potential nitrogen and phosphorus release from farmland exposed to saltwater. Field monitoring stations document the effect of storm events on nutrient release in situ. Data will be coupled with remotely sensed data on the extent of saltwater intrusion and farmland to estimate potential nutrient export to the Chesapeake Bay. We will discuss how our findings can be used to inform salt marsh conservation practices, including the management of problem species Phragmites australis, prioritize protected land acquisition, and probe the capacity of migrating wetlands and transitioning forest to buffer water quality, which could provide the basis for a best management practice for coastal farms.