The Diet, Energy Budget and Predation Impact of Early-Juvenile Coastal Pacific Hake in the Northern California Current

The coastal Pacific hake stock is the largest of the three distinct stocks (coastal, Puget Sound and Strait of Georgia) of Merluccius productus in the eastern Pacific Ocean. The stock ranges from the coast of southern California to British Columbia and supports a major commercial fishery. Coastal Pacific hake have historically been assumed to spawn within the southern California Bight between January and March, and migrate north to coasts of Oregon, Washington and British Columbia during the summer to feed. In the fall, they are thought to return to southern California. There is recent evidence, however, that during warm El NiƱo years, the spawning grounds and distribution of pre-recruit Pacific hake can be found further north, off Oregon and northern California, resulting in high densities of early-juvenile (Age-0 and Age-1) Pacific hake off the Oregon coast. The implications of this are not yet clear, though it is possible that juvenile Pacific hake will compete for food with the juveniles of other species, including salmon and rockfish. In the southern California Current, the diet of early-juvenile Pacific hake has included calanoid copepods and euphausiids and it is likely that these remain important prey items off the coast of Oregon, but this has not yet been determined. In this project, we will assess the diet, energy budget and predation impact of early-juvenile Pacific hake off the Oregon Coast. This research is funded by Oregon Sea Grant.