The North Pacific hake, Pacific hake, Pacific whiting, or jack salmon (Merluccius productus) is a ray-finned fish in the genus Merluccius, found in the northeast Pacific Ocean from northern Vancouver Island to the northern part of the Gulf of California. It is a silver-gray fish with black speckling, growing to a length of . It is a migratory offshore fish and undergoes a daily vertical migration from the surface to the seabed at depths down to about . It is the object of an important commercial fishery off the West Coast of the United States, and annual quotas are used to prevent overfishing.
Description
Its length is about 3 ft (90 cm) and it can live up to 20 years. Its coloration is metallic silver-gray with black speckling and pure silvery white on the belly. The North Pacific hake has two dorsal fins and a truncated caudal fin. Its pectoral fin tips usually reach to or beyond the origin of its anal fin. The caudal fin is always concave.
Reproduction
North Pacific hake spawn from January to June. They may spawn more than once per season, so absolute fecundity is difficult to determine. Historically, inshore female Pacific hake matured at 15 in (37 cm) and 4–5 years of age. Currently, length at 50% maturity for females in the Port Susan North Pacific hake population is about 8.5 in (21.5 cm), compared to 11.7 in (29.8 cm) in the 1980s. Females mature at 3–4 years of age and 13.4 to 15.7 in (34–40 cm), and nearly all males are mature by age three and as small as 11 in (28 cm).
Ecology
They occur from the surface to depths of . North Pacific hake are nocturnal feeders that undergo daily vertical migrations off the bottom to feed on a variety of fishes and invertebrates. Their diet includes shrimp, plankton, and smaller fish such as lanternfish. They are an important prey item for sea lions, small cetaceans, and dogfish sharks.
The three recognized stocks of Pacific hake are a highly migratory offshore (or coastal) stock that ranges from southern California to Queen Charlotte Sound, a central-south Puget Sound stock, and a Strait of Georgia stock. The offshore North Pacific hake stock spawned off south-central California to Baja California in January and February during the 1960s, 1970s, and 1980s. In spring and summer, adults migrated northward to feed to as far as central Vancouver Island (and as far as Queen Charlotte Sound in some years). In the fall, adults migrated southward toward spawning grounds. Since the early 1990s, a percentage of the offshore stock has remained off the west coast of Canada year round and some Pacific hake have been observed spawning off the west coast of Vancouver Island. Resident Pacific hake in Puget Sound spawn in Port Susan and Dabob Bay from February through April. The Strait of Georgia resident stock aggregates to spawn in the deep basins of the south-central strait, where peak spawning occurs from March to May.
Fisheries and conservation
Pacific hake support one of the most important commercial fisheries off the West Coast of the United States. Of the three recognized stocks mentioned, the latter two stocks are managed by state and local management agencies, but the offshore, or coastal, fishery in U.S. waters is managed by the Pacific Fishery Management Council through its Pacific Coast Groundfish Fishery Management Plan. Originally approved in 1982, the plan now manages over 90 different species through a number of measures, including harvest guidelines, quotas, trip and landing limits, area restrictions, seasonal closures, and gear restrictions (such as minimum mesh size for nets). Annual quotas are the primary management tool used to limit the catch of hake. Pacific hake were declared overfished by the US government in 2002. The stock was declared rebuilt and no longer depleted in 2004. The coast-wide (U.S. and Canada) Pacific hake stock is assessed annually by a joint technical team of scientists from both countries.
In 2003, the U.S. and Canada signed an agreement that allocates a set percentage of the Pacific hake catch to American and Canadian fishermen over the next decade, and established a process for the review of science and the development of management recommendations. Beginning in late 2007, management of Pacific hake and related science activities was coordinated under the provisions of this international treaty with Canada.