Clean Boater Program

Sensitive Habitats

Long Island Sound provides invaluable habitats for many different species of birds, mammals, fish, and shellfish. It is home to lobsters and clams, herring and striped bass, eagles and terns, harbor seals and more. Rocky shores, salt marshes, mud flats, and eelgrass beds provide important nursery areas, feeding grounds, and refuges from predators. The health of these habitats depends on water quality.

Impacts from Boating

These habitats are particularly sensitive to impacts from boating-related activities. Boat propellers and wakes can destroy eelgrass and can cause bank erosion. Hazardous materials, sewage, and marine debris affect water quality and degrade habitat. The resulting pollution can close shellfish beds, cause algal blooms and fish kills, and trap, injure or kill wildlife. Choices you make as a boater will affect the water quality of LIS and its impact on marine life.

Submerged Aquatic Vegetation

Submerged aquatic vegetation (SAV) are rooted, vascular plants that grow completely underwater in coastal waters and inland lakes. SAV represent some of the most productive shallow water habitats on the earth. Barnacles, scallops, mussels, and eggs of aquatic organisms attach to the surface of the plants’ leaves and stems. Beds of these plants serve as nursery areas for commercially important finfish and shellfish and provide shelter for juvenile scallops, fish and animals because their dense underwater canopy provides refuge from predators. Motorboat propellers crossing through beds can "mow" the vegetation or leave long scars that can persist for years or decades. Turbulence from propeller wash and vessel wakes can dislodge sediments, break off leaves, or uproot plants. Also, mooring chains swinging around their mooring blocks can denude circular patches within a bed.


Eelgrass is a type of SAV found in Connecticut waters, which are among the most productive marine habitats, providing shelter and feeding opportunities for a wide variety of fish and invertebrates including winter flounder, bluefish, striped bass and blue crabs. Eelgrass abundance has declined dramatically in the past 20-30 years, most likely from a combination of natural and human factors (disease, water clarity, nutrient loading, mechanical damage and water temperature).

Tips for Sensitive Habitats
  • Proceed slowly in shallow areas and minimize your wake to avoid erosion.
  • Do not disturb wildlife.
  • Avoid contact with submerged aquatic vegetation. (SAV)
  • Use marked navigational channels and obey speed limits.
  • Avoid anchoring in eelgrass beds.
  • Buoy your mooring lines to keep them from scraping away SAVs on the bottom.
Content Last Updated on December 26, 2019.