Prepared by the University of Connecticut and the Connecticut DEP, with the support of researchers and organizations throughout the Long Island Sound watershed.
Establishing restoration objectives for eelgrass in Long Island Sound


Zostera marina is a vascular, rooted plant found along the east coast of the United States, south to North Carolina and all along the West coast, including Alaska. (photo courtesy of P. Auster, University of Connecticut)

The Connecticut Department of Environmental Protection (CTDEP), the U.S. Geological Survey (USGS) and the Long Island Sound Study (LISS) are implementing a project to establish restoration objectives for eelgrass (Zostera marina) beds in the coastal waters of Long Island Sound. Both the LISS Habitat Restoration Work Group and CTDEP are concerned about the long-term, demise of eelgrass in Long Island Sound (LIS). Eelgrass restoration is one of the habitat restoration goals listed in the 1994 LISS Comprehensive Conservation and Management Plan.

The project focused primarily on how nitrogen loading may be affecting eelgrass in Connecticut’s coves, embayments and tidal rivers and management measures that can be taken as appropriate. Scientific research has established a strong relationship between nitrogen loading and eelgrass growth and survival. Excess nitrogen favors the growth of phytoplankton, epiphytes and macroalgae, which out-compete eelgrass for light and space. There are other biotic and abiotic factors that affect eelgrass, but the current body of research indicates that the degree of nitrogen loading, either alone or in concert with other factors such as temperature, can often explain the loss of eelgrass. In Connecticut’s waters, this relationship has not yet been established with the certainty needed to develop and implement management measures.

The goal of the project was to provide a literature review of the current knowledge of eelgrass biology with specific reference to Long Island Sound. A second goal of the project was to evaluate three case study sites in Long Island Sound and develop recommendations for habitat criteria guidelines for eelgrass and elucidate the effects of nitrogen loading on eelgrass distribution in Long Island Sound. The results of the projects are presented in two reports available for download and are summarized in this website.