Documentation of methods for the estimation of run-size of Fraser River sockeye and documentation of assessments of catchability in purse seine test fisheries

Since 1992, a series of inquiries have been directed towards the management of Fraser River sockeye. The 1994 Management Season was notable for the difficulties identified in the estimation of the abundance of adult returns of Fraser River sockeye. The run-size estimation models and run-reconstruction methodology in use in 1994 have been documented (Anon 1995) however subsequent changes to methodology have not been updated.

In 2008 a Bayesian version of the cumulative normal model was develop by Catherine Michielsens. Further developments addressed the uncertainty in estimates of catchability, principally for purse seine test fisheries for summer and late-run sockeye, but also secondarily for gillnet test fisheries for Early Stuart and Early Summer run sockeye. These important achievements have been presented to the Fraser River Panel, its Technical Committee as well as the scientific community and have received general acceptance but remain otherwise undocumented in detail in the peer-reviewed literature. This leaves the Fraser River Panel, the Staff and data collection programs vulnerable to scrutiny in the event of a future formal inquiry into their methodology.

This concept proposal is to assist PSC Staff to document these methods in the peer reviewed literature. Since the Panel is currently reviewing the test fishing program on Fraser River sockeye and pink salmon, this proposal is timely as we will document the importance of consistent test fishing operations as well as its application in important models in fishery management in the peer reviewed literature of the scientific community.

S16-I22 In-season assessment and management of salmon stocks using a Bayesian time–density model Report 2016