PSI Research Scientist Tessa Francis sends us this photo of herring eggs on eelgrass (click photo to enlarge), part of a new forage fish study in collaboration with NOAA’s Northwest Fisheries Science Center and the Washington Department of Fish and Wildlife. The study, which began earlier this month examines the possible link between eelgrass abundance and herring populations in Puget Sound.

Eelgrass is a key substrate used by Pacific herring for spawning in the nearshore habitats of Puget Sound. Because some patches of eelgrass are shrinking, some scientists have postulated that recovery of Puget Sound herring is linked to increasing eelgrass abundance.

Francis and her collaborators are testing this hypothesis by measuring herring use of eelgrass and other substrates around Puget Sound. Herring also use other species of submerged vegetation, like Gracillariopsis, Sargassum, and Ulva; as well as rock and gravel in some locations. The team will measure egg mortality rates on each substrate type.

The study is part of a larger research effort to understand the status and health of forage fish populations in the region.