Biological and Ecosystem Science Research

Since its inception, the IPHC has had a long history of research activities devoted to describe and understand the biology of the Pacific halibut (Hippoglossus stenolepis). At present, the main objectives of the Biological and Ecosystem Science Research Program at IPHC are to: 1) identify and assess critical knowledge gaps in the biology of the Pacific halibut; 2) understand the influence of environmental conditions in the biology of the Pacific halibut and its fishery; and 3) apply the resulting knowledge to reduce uncertainty in current stock assessment models.

The primary biological research activities at the IPHC that follow Commission objectives and selected for their important management implications are identified and described in the proposed Five-Year Research Plan for the period 2017-21. These activities and their specific aims are summarized in five major areas:

1. Reproduction: Studies in this area aim at providing information on the sex ratio of the commercial catch and to improve current estimates of maturity.
2. Growth and Physiological Condition: Studies in this area aim at describing the role of some of the factors responsible for the observed changes in size-at-age and to provide tools for measuring growth and physiological condition in Pacific halibut.
3. Discard Mortality and Survival: Studies in this area aim at providing updated estimates of discard mortality rates in both the longline and the trawl fisheries.
4. Migration: Studies in this area aim at further understanding reproductive migration and identification of spawning times and locations as well as larval and juvenile dispersal.
5. Genetics and Genomics: Studies in this area aim at describing the genetic structure of the Pacific halibut population and at providing the means to investigate rapid adaptive changes in response to fishery-dependent and fishery-independent influences.

Overall, the research program at IPHC aims at providing information on factors that influence the biomass of the Pacific halibut population (e.g. distribution and movement of fish among IPHC Regulatory Areas, growth patterns and environmental influences on growth in larval, juvenile and adult fish, drivers of changes in size-at-age) and, specifically, of the spawning (female) population (e.g. reproductive maturity, skipped spawning, reproductive migrations) and resulting changes in population dynamics. Furthermore, the research activities of IPHC are also intended to provide information on the survival of bycatch and wastage Pacific halibut and eventually refine current estimates of discard mortality rates.