Documenting Intertidal Forage Fish Spawning on the Washington State Outer Coast to Support Long-Term Marine Spatial Planning

Obligate intertidal-spawning forage fish are an important part of the marine food web, yet little is known about the spatiotemporal distribution of spawning on the Washington outer coast. As part of a coast-wide marine spatial planning process, the Washington Department of Fish and Wildlife, in collaboration with the Hoh, Makah, Quileute Indian Tribes, and Quinault Indian Nation, conducted a 24-month (October 2012 – October 2014) survey in an effort to document the presence of eggs deposited by forage fishes spawning in the intertidal, primarily surf smelt Hypomesus pretiosus. Using existing shoreline sediment composition and geoform classifications of beaches, a total of 158 miles of likely spawning beaches were identified. Over the two-year survey period, 89% of possible spawning beaches were sampled and 40 smelt spawning sites were documented. Smelt spawn was documented in each month from January through October, and peak spawn abundance occurred from May to September. Spawning sites were located in the northern central coast, ranging as far south as 47.27483, -124.23372 and as far north as 47.93226, -124.64301 (WGS84). These results expand the known spawning window 5 months and 30 miles northward of what had been documented as a result of limited survey effort prior to 2012.