North Pacific hake

North Pacific Hake Fish
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Gadiformes
Family:	Merlucciidae
Subfamily:	Merlucciinae
Genus:	Merluccius
Species:	M. productus
Binomial name
Merluccius productus (Ayres, 1855)

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 90 cm (3 ft). 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. An expansion of the range of the Humboldt squid is causing concern because it is a voracious predator of the North Pacific hake.

Description

File:Merluccius productus1.jpg

Merluccius productus California, Cordell Bank National Marine Sanctuary

Its length is about 3 ft (90 cm) and it can live up to 15 years. Its coloration is metallic silver-gray with black speckling and pure silvery white on the belly. North Pacific hake have two dorsal fins and a truncated caudal fin. Their pectoral fin tips usually reach to or beyond the origin of their anal fin. The caudal fin is always concave.

Reproduction

The North Pacific hake spawns 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 four to five 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 three to four years of age and 13.4 to 15.75 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 1,000 m (3,300 ft). North Pacific hake are nocturnal feeders that undergo daily vertical migrations off the bottom to feed on a variety of fishes and invertebrates. Its diet includes shrimp, plankton, and smaller fishes. 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 (SOG) stock. The offshore North Pacific hake stock spawned off south-central California to Baja California in the winter months of 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 SOG resident stock aggregates to spawn in the deep basins of the south-central Strait of Georgia, where peak spawning occurs from March to May.

Fisheries

Pacific whiting supports 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 (FMP).

Originally approved in 1982, the Groundfish FMP 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 whiting. Pacific whiting was 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 whiting 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 whiting 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 whiting and related science activities was coordinated under the provisions of this international treaty with Canada.

The Marine Stewardship Council (www.MSC.org) certified the midwater Pacific hake (whiting) fishery as sustainable on 21 October, 2009.

The local and state-managed Puget Sound and SOG stocks are "species of concern" - species that NOAA Fisheries Service has concerns about regarding population status and threats, but has insufficient information to indicate a need to list the species under the Endangered Species Act. No directed commercial fishery for this stock has occurred since 1991.

Conservation

Overharvesting is the main threat to North Pacific hake. The National Marine Fisheries Service received a petition to list the North Pacific hake under the Endangered Species Act (ESA). The petition was denied on 24 November 2000 (65 FR 70514), but concerns and uncertainties remained. During the review for ESA listing, the Georgia Basin distinct population segment (DPS) was identified to include both the Puget Sound and Strait of Georgia stocks. The Georgia Basin DPS of the North Pacific hake (called Pacific hake by NMFS) was made a US National Marine Fisheries Service Species of Concern. Species of Concern are those species about which the National Oceanic and Atmospheric Administration, National Marine Fisheries Service, has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the Endangered Species Act.

The expanding range of the Humboldt squid is also a cause for concern, because they are voracious predators of hake and can substantially reduce their populations.

Further reading

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External links

• Froese, Rainer and Pauly, Daniel, eds. (2006). "Merluccius productus" in FishBase. April 2006 version.