A Comparative Analysis of Age Estimates for Greenland Halibut, Reinhardtius hippoglossoides matsuurae, from the Northwestern Pacific Ocean based on Different Methodological Approaches

Abstract

The significant decline in the abundance of the Greenland halibut Reinhardtius hippoglossoides matsuurae in the Northwest Pacific was one of the impetuses to scrutinize the age determination methods for this species based on different age-recording structures. The present study was carried out in accordance with recommendations of the Northwest Atlantic Fisheries Organization (NAFO) and the International Council for the Exploration of the Sea (ICES). An analysis of age determination data for the Greenland halibut has shown underestimation of age estimated using scales or whole otoliths compared to the technique using otolith sections through the peri-sulcular tuberosity. A resource exploitation strategy based on incorrect age determination can either be the major cause of negative trends in the status of the Greenland halibut stock or have a combined effect with natural factors.