Ontogenetic and spawning migration of Pacific halibut: a review

Pacific halibut (Hippoglossus stenolepis) supports one of the most valuable groundfish fisheries in the North Pacific Ocean and the north American component has been managed by the International Pacific Halibut Commission since 1923. From its establishment, IPHC’s work has been focused on data collection and research programs to better understand stock dynamics, extent, and behavior across its range. In this review we summarize the 100 years of migration research available for Pacific halibut, with a focus on tagging experiments. A visual representation of all tags deployed and recovered is included, and all of the information available from different research (e.g. genetic analyses, oceanographic models, catch trends, IBM) has been unified into a conceptual model of Pacific halibut movement from southern California through the Bering Sea. From spawning grounds in the Gulf of Alaska, eggs and larvae are transported westward, some crossing Aleutian Island passes into the Bering Sea. Once settled, there is compensatory migration as some juveniles move back into the Gulf of Alaska. In the Gulf of Alaska, juveniles and adults exhibit net migration eastward and southward along the continental shelf of the US and Canadian coasts. Adults undertake seasonal migrations from feeding grounds to spawning grounds. While little information is available for the western side of the Pacific halibut range, research suggests a constant exchange across the Bering Sea between the eastern and western grounds. The hypothesis of multiple migratory behaviors is suggested. This review will serve as a guide for current modeling efforts and future research planning.