|
Life history: Halibut spawning takes place during the winter months with the peak of activity occurring from December through February. Most spawning takes place in deep waters of 200 to 300 fathoms. Male halibut
become sexually mature at 7 or 8 years of age, and females attain sexual maturity at 8 to 12 years. Females lay two to three million eggs annually, depending on the size of the fish.Halibut are the largest of all
flatfish. The largest ever recorded for an Alaska halibut was a 495-pound fish caught near Petersburg, Alaska.
Fertilized eggs hatch after about fifteen days. Free-floating eggs and larvae float for up
to six months and are transported up to several hundred miles by currents of the North Pacific. During this stage, many changes take place in the young halibut, which rise to the surface and are carried to shallower
waters by prevailing currents. In the shallower waters, young halibut then begin life as bottom dwellers. Most young halibut ultimately spend from five to seven years in rich, shallow nursery grounds as in the Gulf
of Alaska and Cook Inlet.
Younger halibut, up to 10 years of age, are highly migratory and generally migrate in a clockwise direction east and south throughout the Gulf of Alaska. Halibut in the older age
classes tend to be much less migratory. Older fish often use both shallow and deep waters over the annual cycle, however they have much smaller “home ranges” than younger, more migratory fish.Younger halibut, up to
10 years of age, are highly migratory and generally migrate in a clockwise direction east and south throughout the Gulf of Alaska.
|