The Sippewissett microbial mat is a microbial mat in the Sippewissett Salt Marsh located along the lower eastern Buzzards Bay shoreline of Cape Cod, about 5 miles north of Woods Hole and 1 mile southwest of West Falmouth, Massachusetts, in the United States. The marsh has two regions, the Great Sippewisset Marsh to the north and Little Sippewisset Marsh to the south, separated from each other by a narrow tongue of land (Saconesset Hills). The marsh extends into an estuary in which the intertidal zone provides a dynamic environment that supports a diverse ecology, including threatened and endangered species such as the roseate tern (Sterna dougallii).[1] The ecology of the salt marsh is based in and supported by the microbial mats which cover the ground of the marsh.