Shoreline Restoration Design to Facilitate Spawning Activity of Forage Fish

Shoreline restoration is an action agenda item for the Puget Sound Partnership, Puget Sound Initiative, and other Washington State agencies.  Projects range from small bulk head removal and shoreline modifications, to large-scale remediation and restoration. We conducted a variety of projects over the past several years, and results are beginning to take shape.  Traditional requirements for forage fish spawning habitat include adequate shading, proper substrate grain size, and beach access to specific tidal ranges.  Designing a beach restoration to meet these requirements is important, but does not guarantee forage fish will return to spawn.  Surveys from restoration monitoring have found that factors such as beach orientation, localized tidal activity, and beach slope gradient also contribute to spawning presence and successful egg development.  We have found strong spawning activity even in the absence of shading, when other factors were met.  Sediment size was found to be especially important for egg survival, as surf smelt eggs that become buried just below the surface of the substrate, as a result of moderate wave action, experienced decreased desiccation.  These results are important as continued efforts to restore Puget Sound shorelines are funded and researched.