BC Area Fish: Pacific Halibut
The Pacific Halibut (Hippoglossus stenolepis) is found on the continental shelf of the North Pacific Ocean and Bering Sea. Halibut stocks diminish as one moves further south from Washington State through to California. Some Halibut specimens will travel up to 2,000 miles. The world record is 459 lbs. and was caught in Dutch Harbor, Alaska in June 1996.
Halibut live on or near the bottom of the ocean, preferring water temperatures between 3-8 degrees Celsius (37-46 degrees Fahrenheit). Having a relatively flat, diamond-shaped body with darker coloring on the topside and a light (whitish) underside for camouflage this avoids detection by both prey and predator.
Females grow to weights of over 470 lbs., live to a maximum age of 35-45 years and may attain a length of 9 ft. By comparison, males rarely exceed 40 lbs. and their maximum life expectancy is about 25 years. The females are more numerous than the males and grow faster, except during the early stages of development.
From November to March each year mature Halibut migrate from the shallower coastal waters to the edge of the continental shelf between depths of 600 – 1500 ft. to spawn in groups. Spawning takes place by “broadcast spawning”, a method where several females and males release their eggs and sperm into the water column at the same time. The females release between 500,000 to 4 million eggs to be fertilized.
As the eggs develop into larvae and grow, they drift slowly upward, travelling great distances with the ocean currents in a counter-clockwise direction around the Northeast Pacific. After this free-floating stage of 6 months the young fish eventually settle at the bottom of their nursery area found in shallow fertile coastal waters where they’ll feed for another 2-3 years before venturing to deeper waters to continue feeding on larger prey.
Amazingly, when they hatch from eggs, Halibut resemble normal fishes, with an eye on each side of the head. As they mature over the next few years, the bones on the left side of the skull grow significantly faster than on the right side, so the left eye and nostril slowly migrate to the right side where the Halibut will eventually have both of their eyes on the same side of their head. The jaws, however, do not change significantly, so the adults bite sideways, from right to left.
The females are more numerous than the males and grow faster, except during the early stages of development. At about 10 years of age, females reach spawning maturity and return to the same grounds where they were hatched.
As Halibut are large, active predators at the top of the food chain, few species attack and eat them. Halibut feed near the ocean bottom with prey consisting of Crabs, Squid, Herring, Mackerel and their favorite prey Octopus.
Halibut will feed on crabs, squid, herring, mackerel, geoduck and octopus. They will feed mid-water as well as the bottom.
The governments of the U.S. and Canada, through the International Pacific Halibut Commission, jointly manage the Commercial Halibut fishery in North Pacific Ocean waters. In 2013, Canada’s Pacific halibut catch was 3,746 tonnes with an export value of $44.5 million.
Canada exports over 96% of its commercial catch to the U.S. market with the remainder destined for Taiwan and Japan.