Both docks and moored boats can cause eelgrass decline by blocking light, studies suggest. Docks along Bainbridge Island. While each dock and boat may be small, the combined effect of many overwater structures can add up. Pilings can also create depressions in sediments that discourages eelgrass growth. Alternative building materials for docks such as metal grating may let more light into the water and allow more eelgrass to survive.
More study is needed, scientists say, on what materials work best.
Puget Sound Research 95, Overwater Structures and Impacts On Eelgrass in Puget Sound, K. Fresh, et. Everyone who uses this pristine cruising ground has a responsibility to take care of it. Protect Puget Sound Puget Sound is a prime boating place. Over 500,000 boats are moored in the Puget Sound area permanently. An estimated 300,000 to 600,000 boats may be on the Sound annually.