In these waters the richest halibut grounds are found around the Faroe Islands, the southwest coast of Iceland and in the cold waters off the coast of Norway. Investigations carried out in the northwest Atlantic indicate that halibut spend the winter months in deeper water and move to shallower waters during the summer. Two fisheries research cruises, carried out in the deep waters along the edge of the Scotian Shelf in March and November of 1982, corroborate these earlier results. During the spring cruise, halibut were caught in far greater numbers than during the late fall cruise. These results again indicate that halibut move into and out of these deep waters on a seasonal basis.
European investigations show similar migrations of halibut occurring in the northeastern Atlantic.
There is some evidence to suggest that fish which spend the summer months in the North Sea, Barents Sea, and Bear Island area migrate into the deep fjords off the coast of Norway during the winter. At all times of the year on both sides of the Atlantic, halibut prefer to inhabit areas of relatively hard bottom made up of rock, sand, clay, or gravel. They have been found in water ranging from less than 1 C to water as warm as 15 C but seem to prefer temperatures ranging between 3 C and 9 C. Halibut which have been tagged, released, and subsequently recaptured indicate that they are capable of moving great distances. Life History Halibut spawn between February and May in water ranging from 700 to 1000 meters deep over bottom consisting of clay or soft mud. These depths and bottom types are usually found on the deep water edges of banks, the continental slopes, and in some fjords.