Animalia Life

Pollachius virens
FAMILY
Gadidae
TAXONOMY
Pollachius virens Linnaeus, 1758, Oceano Europeo.
OTHER COMMON NAMES
English: Coalfish, saithe.
PHYSICAL CHARACTERISTICS
Three separate dorsal fins, two separate anal fins. Dorsal and anal fins separated by narrow gaps. A very small chin barbel present. Lateral line pale. Brownish-green dorsally, slightly paler ventrally. Fins same color as body.
DISTRIBUTION
The pollock occurs on both sides of the North Atlantic. In the western North Atlantic, it is found from the Hudson Strait to Cape Hatteras, North Carolina. In the eastern North Atlantic, from Spitzbergen to Bay of Biscay. Also found in Barents Sea and around Iceland.
HABITAT
The pollock is strongly pelagic and occurs most frequently over depths of 361–590 ft (110–180 m), although its range can vary with food supply and season. Adult fishes occur in temperatures as low as 32°F (0°C), and they do not tolerate temperatures >52°F (11°C). Young stages are known as harbor pollock and are commonly found in bays and estuaries throughout their range.
BEHAVIOR
The pollock is a schooling species and is found throughout the water column, not just near bottom. Pollock engage in short migrations associated with temperature changes or for spawning, but otherwise remain fairly stationary within their range.
FEEDING ECOLOGY AND DIET
The pollock feeds most actively on pelagic prey. Important prey items include euphausiids (especially Meganyctiphanes norvegica), fishes, and molluscs (especially the squid Loligo). Crustaceans are most important in juveniles’ diets. Fishes comprise only 12% of juveniles’ diets and 28% of adults’ diets.
REPRODUCTIVE BIOLOGY
In the western Atlantic, spawning occurs from September to April with peaks between December and February. Both sexes reach sexual maturity during their third year, at lengths of 19.9 and 18.9 in (50.5 cm and 47.9 cm) in males and females, respectively. Spawners occasionally form huge aggregations. Spawning occurs over hard, rocky bottoms, and activity peaks when temperatures are between 40.1 and 42.8°F (4.5 and 6.0°C). Eggs and larvae develop pelagically, and small pelagic juveniles begin to enter inlets in February and March, when they are <2.0 in (50 mm) long.
CONSERVATION STATUS
Not listed by the IUCN. Although there are recognized western Atlantic centers of abundance of pollock on the Scotian Shelf, Georges Bank, and Gulf of Maine, tagging studies suggest considerable movement of pollock between these centers and accordingly, pollock from Cape Breton, Nova Scotia, and south continue to be assessed as a single, unit stock by United States scientists. The total nominal catch from this stock, including commercial and recreational, has been steadily declining since 1986, and the 1996 total represents an 82% reduction from 1986 landings. Spawning biomass is increasing, but within the Gulf of Maine, stock abundance and biomass remain low. Overall the stock is considered to be fully exploited, but not yet in an overfished condition.
SIGNIFICANCE TO HUMANS
Pollock is an important commercial species, and it is marketed in several ways: fresh, as chilled fillets, frozen, canned, dried and salted, and in brine. A large percentage of the 1987 total landings 524,680 tn (475,981 t) was landed in the northeast Atlantic by Norway, Iceland, France, Germany, the United Kingdom, and Denmark. Most of the catch in the northwest Atlantic is landed by Canada, the United Kingdom, and France.

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