Comparing self-reported incidental catch among fishermen targeting Pacific halibut and a fishery independent survey

Abstract This paper compares observations of commercial fishermen with a fishery-independent survey, and explores putative relationships between characteristics of fishing operations and incidental catchin the Pacific halibut fisheryin Southeast Alaska. Results from a multiple factor analysisdemonstrate statistically significant relationships between fishing characteristics and the incidental catchof various species. Results from a proportional odds logistic regression model indicate the presence of a strong unavoidable component of incidental catchin the halibut fishery. Consequently, patterns of incidental catchin this fisherygenerally paralleled patterns of incidental catchin a fishery-independent stock assessmentsurvey that uses similar gear. This suggests that increased onboard monitoring of this fleet by cameras or human observers is unlikely to reveal broad trends in incidental catchthat are not already apparent in the fishery-independent stock assessmentsurvey. Nevertheless, weaker statistically significant relationships in the model indicate that incidental catchmay be influenced by observable and controllable characteristics of fishing operations (e.g., fishing grounds, season, vessel length, gear configuration). This suggests a proportional odds model like the one presented in this paper could be used to generate operation-specific estimates of incidental catchby species from incidental catchesobserved in fishery-independent surveys based on known characteristics of fishing operations.