An edition of: WaterAtlas.orgPresented By: Sarasota County, USF Water Institute

Sarasota County Water Atlas


Oyster reefs are vital structural components of estuarine and bay ecosystems. Not only are they important commercial and recreational resources, they are a keystone species in that they play a vital role in sustaining the structure of an ecological community. Without them, many organisms dependent upon oyster reefs for survival would probably not be able to subsist. As a keystone species, oyster reefs provide critical habitat and cover for wide variety of aquatic organisms; the larvae, spat, and adult oysters are an important food source for birds, fish, and other aquatic organisms; they play a crucial role in water quality improvement through their capacity to filter 30 to 60 gallons of water per adult oyster, per day; and, as a result of their sessile nature and adaptation to a wide salinity range, they function as key bioindicators of the relative health of aquatic ecosystems in bays, estuaries, and the tidal extent of coastal creeks.

But, according to a recent global assessment of oyster reef habitat (Shellfish Reefs at Risk) conducted by the Nature Conservancy and its partners, oyster reefs are one of, and likely the most, imperiled marine habitat on earth. It estimates that about 85% of the earth's oyster reefs have been lost through stressors such as destructive fishing practices, coastal development activities such as dredging and filling, hydrological alterations, construction of dams, poorly managed agriculture, and urban development.

Because of their valuable attributes and the need for a comprehensive data set of oyster habitat, Sarasota County initiated a project to map different types of Eastern Oyster (Crassostrea virginica) habitat in county bays and creeks. In recent years, projects had been conducted by the Sarasota Bay Estuary Program, Charlotte Harbor National Estuary Program, Sea Grant, and Sarasota County to develop historical and current maps depicting the location and extent of oyster habitat in county bays. But, there had been limited efforts to map oysters in the county coastal creeks. The project was completed in 2013, and data collected will serve as a baseline to compare with future trends as watersheds are altered through development or restoration processes. The data may also aid in the identification of restoration sites; future oyster reef restoration projects may be the key to the long-term survival of oysters in the region.