Regional Variation in the Size of Maturity of Two Species of Tanner Crab ( Chionoecetes bairdi and C . opilio ) in the Eastern Bering Sea, and Its Use in Defining Management Subareas

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Author: Somerton, David A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1981
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Bering Sea; Chionoecetes opilio; Chionoecetes bairdi; Tanner crab
• Online Access: http://dx.doi.org/10.1139/f81-022; http://www.nrcresearchpress.com/doi/pdf/10.1139/f81-022

Minimum size limits for the commercial harvest of tanner crab (Chionoecetes bairdi and C. opilio) are based on the sizes of sexual maturity. Establishing such size limits in the eastern Bering Sea is complicated by a large regional variation in the size of maturity. A computer technique was developed which partitioned the eastern Bering Sea into subareas that were relatively homogeneous with respect to the size of maturity. The best partitioning for C. bairdi was a separation of the eastern Bering Sea into two subareas along 167°15′N longitude. No acceptable partitioning could be found for C. opilio. The size of 50% maturity for male C. bairdi was estimated to be 108.9 mm carapace width in the western subarea and 117.0 mm in the eastern subarea. The size of maturity upon which the current minimum size for C. bairdi is based is nearly the same as the size estimated for the western subarea but significantly less than the size estimated for the eastern subarea.Key words: crabs, size of maturity, Chionoecetes bairdi, Chionoecetes opilio, tanner crab, eastern Bering Sea