Aquaculture FAQ - Why are oysters considered a keystone species?

Filter-feeding bivalve molluscs are considered to be a "keystone species" because of the important ecological services they provide to maintain or improve water quality and clarity, and cycle nutrients between the water column and bottom dwelling species. The diversity and abundance of molluscan shellfish populations are often cited as indicators of the environmental quality and overall health of coastal ecosystems.

Delaware is undergoing a period of unprecedented population growth and development in southernmost Sussex County and the Inland Bays watershed. Nutrient input from commercial and residential development, municipal, agricultural activities and other non-point sources has led to increased eutrophication and reduced water quality in Delaware's Inland Bays (Rehoboth, Indian River, and Little Assawoman). Degradation of water quality has resulted in episodic fish kills and toxic algal blooms, habitat loss and other environmental problems.