Salt marsh decomposition rates using Tea Bag Index in two Southeastern MA marshes in the towns of Fairhaven and Dartmouth from 2020-2022.

Natural disturbances, sea level rise, and historic human impacts to salt marshes have increased impounded water on marsh surfaces, resulting in vegetation loss and the associated loss of important ecosystem services such as carbon storage. Runnels are a climate adaptation technique designed to restore salt marsh habitat by reestablishing a tidal connection between impounded water and a nearby drainage feature. However, panne formation and runnel restoration can alter carbon decomposition. We measured decomposition using the Tea Bag Index at two marshes, one in Fairhaven and the other in Dartmouth, MA. We repeated measurements for three years: 1 year prior to runnel creation, and two years post. We measured decomposition at three spatial zones, the center of the panne, landward of the panne, and seaward of the panne.