|This page uses Creative Commons Licensed content from Wikipedia (view authors).|
Eelgrass (Zostera marina) is an underwater grass that thrives in marine and estuarine water bottoms and spreads through rhizomes, or roots.It has been estimated by the Washington Department of Natural Resources (DNR) that Puget Sound is occupied by approximately 26,000 acres (105 km²) of eelgrass. Research has shown that eelgrass beds in Puget Sound can be found in two different habitats: flats, which can be described as either large, shallow bays or small "pocket" beaches, and fringe beds[clarification needed] along steep shorelines. Beds ofeelgrass provide a vital link in the nearshore foodweb, creating underwater forests for biota such as salmon, herring, sand lance, and numerous invertebrates. Eelgrass beds provide nutrients and shelter for various biota in Puget Sound. As eelgrass and other seagrasses decay, it combines with other dead matter. This rich detritus is a staple for invertebrates, which are fed upon by salmonids, birds and other predators. Eelgrass functions as a protective cover from the predators for juvenile salmon and as a nursery for herring that deposit eggs among bed. Herring, in turn, are an important food source for juvenile and adult salmon. During low tide, eelgrass beds shelters other small animals from extreme temperatures, and in tideflats the beds act as a sponge for moisture. Eelgrass monitoring is conducted throughout Puget Sound using random sampling under the Submerged Vegetation Monitoring Program, WashingtonDepartment of Natural Resources, Nearshore Program. Results for 2003–2004 were posted in 2005. Many eelgrass populations were holding steady, but sharp declines were noted in five shallow bays in the San Juan Islands and 14 smaller sites in the greater Puget Sound. Eelgrassthroughout the entire Hood Canal showed a steady decline. A number of reasons contribute to the decline in eelgrass population, including, but not limited to: Lack of appropriate substrate to grow upon Lack of or poor-quality light, impacting photosynthesis Changes in climate impacting currents, water temperature and water quality Nutrient input, spurring algae growth, reducing light and oxygen availability Sediment input, reducing light availability and quality Physical alteration of the shoreline, potentially increasing wave energy or altering substrate in the nearshore area, sometimes both The Puget Sound Conservation and Recovery Plan (2005–2007) outlines a number of goals for improving management and health of the state's eelgrass beds. These include increasing protection over eelgrass beds on state-managed aquatic lands, and developing a statewide "seagrass management conservation plan" to be used by local, state and federal agencies.