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starfish in eelgrass (King County)

Eelgrass is found both in large meadows in embayments and as a narrower fringing meadows on beaches with muddy to sandy substrate. Along with Bull Kelp and other macroalgae eelgrass is part of a class of vegetation called "submerged aquatic vegetation" or SAV. This vegetation increases habitat services both capturing sun energy and releasing it into food webs and by increasing structural complexity. Of particular importance, eelgrass and other macroalgae are used by Pacific herring as attachment surfaces for their eggs.


  • DNR has a Eelgrass Monitoring Program that prepares regular reports and are tracking status and trends as part of Puget Sound Vital Signs.
    • DNR works with local governments and tribes, and have a lot more data than represented in their annual monitoring reports.
    • Informal results from their website suggest that maximum depth of eelgrass increases as you move from within Puget Sound towards the Strait.
    • Rapid large scale loss of eelgrass meadows (Wolcott Bay) have been observed by the WDNR eelgrass monitoring program, but have not been explained.
    • Change in eelgrass cover is one of the Puget Sound Vital Signs. Efforts to increase eelgrass cover are focussed on river delta mouths, and the effects of river channelization on delta sediment dynamics.
  • Mumford 2007 provides a synthesis of knowledge about about eelgrass.
    • Mumford 2007 speculates that summer mid-day exposure controls the upper range, while light penetration (lux?) controls the lower range. The absence of Eelgrass west of Nisqually Reach is a result of late day summer low tides, and high tidal range resulting in deep water.
    • Mumford 2007 provides qualitative peer observations that eelgrass density is highest on the fringes of freshwater inputs (like river deltas) where turbidity is still low, but nutrient availability is high.
  • The ShoreZone Geodatabase, produced by DNR provides a sound wide eelgrass and kelp survey.
    • This survey may underestimate eelgrass distribution particularly deeper meadows.
    • It suggests that Puget Sound eelgrass is roughly divided between narrow fringing beds, and large beds in embayments, the largest of which is is Padilla Bay.
  • Pacific Northwest National Laboratory has provided technical leadership on multiple eelgrass mitigation and transplanting projects (mostly associated with ferry docks) which provide the basis for modern eelgrass transplanting methods.
  • Monitoring following eelgrass transplanting at the Northwest Maritime Center Dock observed potential displacement of eelgrass by macroalgae from the presence of anthropogenic rubble as holdfasts.
  • The concept of eelgrass seeding using buoys has been proposed to restoration funders. No known evidence of effectiveness from the Salish Sea.


  • To what extent do eelgrass and macrolagae provide an equivalent set of ecosystem services?

Eelgrass Pages and Files[edit]

The following pages concern eelgrass:

The following on-wiki documents concern eelgrass:

The following off-wiki documents concern eelgrass: