The Salmon Terminal Fishery: a Practical, Comprehensive Timing Model

Abstract

This paper presents a comprehensive model for analysis of data from a salmon terminal fishery. The model includes a new description of salmon run curves, tailored form earlier models of biological growth. It also includes a new equation to describe the process of fishing from a pool of fish that belong to various stages of the salmon run. It allows for variable run timing between fishery and hatchery, and it incorporates test fishery data in a systematic way. A likelihood function is derived that gives an objective criterion for estimating parameters associated with run timing, the fishery, and the test fishery. The model is applied to 4 yr of historical data on the chinook (Oncorhynchus tshawytscha) fishery in Barkley Sound and Alberni Inlet, British Columbia, Canada. Run timing proves to be remarkably consistent from year to year. Time spent by the fish in the fishery is ill-determined from the data, but most other important parameters are relatively insensitive to this uncertainty.