Forage fish are an assemblage of small schooling species also known as bait fish. These include Pacific herring, Northern anchovy, Pacific sand lance, and surf smelt. They are important prey species for Chinook salmon, groundfish and other fish, birds, and mammals. Zooplankton are in turn important prey for forage fish.  

Forage fish depend on clean water and natural shorelines and are susceptible to water quality and habitat degradation. Some species like anchovy spawn in the open water, while others leave their eggs along the shoreline, either in the sand and gravel or in shallow water on submerged aquatic vegetation.  

While all forage fish are important to the Puget Sound food web, our knowledge on abundance and distribution varies between species. Pacific herring are monitored in a Vital Sign indicator, harvested commercially and recreationally in Puget Sound, and serve as one of the only locally harvested baitfish for the salmon and groundfish fisheries.  

The size and timing of Pacific herring spawning varies regionally and from year to year. Despite an overall increase in total spawn biomass in Puget Sound from 2010 to 2020, some populations remain below their 25-year average abundance. These declines in spawning result in reduced prey available for the species that feed on them.   

Although researchers lack official population estimates, reports of anchovy in predator diets and commercial landings in Puget Sound suggest that anchovy abundance increased during 2015 and has remained high since then. There is evidence that this led to shifts in marine mammal distribution and impacted juvenile salmonid survival rates. 

Like anchovy, there are no official estimates for sand lance or surf smelt abundance in the Salish Sea. The Washington Department of Fish and Wildlife and several partners of the PSEMP Forage Fish and Food Webs work group continue to monitor spawning habitat for both species, and have also been investigating sand lance burying habitat.