The Elliott Bay Nearshore Substrate Enhancement Project was undertaken by the Elliott Bay/Duwamish Restoration Program Panel (Panel) in March 1998 at selected sites northeast of Duwamish Head on Washington Department of Natural Resources (WDNR) property and seaward of Seattle tidelands north of Seacrest Park in West Seattle. The King County Department of Natural Resources (King Co, DNR) was selected as project manager subsequent to site investigations by the Washington Department of Fish and Wildlife (WDFW) in 1996. The Panel’s Habitat Development Technical Working Group provided guidance during the project design phase and in the development of the monitoring plan.
Four materials (cobble, quarry spall, pea gravel and oyster shell) were placed in eight plots (four plots each at two sites) to enhance productivity of benthic infauna, increase the distribution and density of macroalgae and other primary producers, and improve the attributes that support resident and migratory marine and estuarine fish species. Specific objectives were identified as follows:
- Increase diversity of bottom substrates
- Increase area of limiting hard bottom substrates
- Provide intertidal substrates for bait fish spawning
- Provide suitable substrates at proper horizons for eelgrass
- Increase volume of physical and protective structures for juvenile and adult resident invertebrates and fishes
- Increase hard structure surfaces for macroalgae
- Remove undesirable bottom debris