Selective action of gillnets on sockeye (Oncorhynchus nerka) and pink salmon (O. gorbuscha) stocks of the Skeena River system, British Columbia ...

• Main Author: Todd, Ian St. Pierre
• Format: Text
• Language: English
• Published: University of British Columbia 2011
• Subjects: Pink salmon
• Online Access: https://dx.doi.org/10.14288/1.0104120; https://doi.library.ubc.ca/10.14288/1.0104120

Exploitation of Skeena River sockeye salmon (Oncorhynchus nerka) has been conducted almost solely by drift gillnets since inception of the commercial fishery in 1877. Selective action of gillnets is a factor which may have contributed to a long term decline in sockeye production and to other features of the population biology. This study was designed to determine the selective properties of nylon gillnets presently in use; to compare these with properties of linen nets used prior to 1955; to adjust age composition estimates of escapement levels prior to 1946; and to re-examine brood year production. In addition, the selective action was examined of the fishery as a whole on sockeye and pink salmon (O. gorbuscha) in 1968. The selective properties of six nylon gillnets ranging in mesh size between 4-5/8 inches and 5-5/8 inches, which corresponded with sizes normally used in the commercial fishery, were to be determined through a simultaneous fishing experiment, and selectivity curves were computed by Holt's ...