NAVIGATION

Skeena Watershed Initiative

Evaluation of a mark-recapture procedure to assess the catchability rate of the Tyee test fishing gill-net

The objective of this project is to evaluate ways to improve Skeena steelhead escapement estimates generated from the Tyee test fishery. Estimates of the Tyee test fishery catchability rate (i.e., the fraction of fish present which are captured during a fishing period) are combined with the number of steelhead captured to produce an estimate of total number of steelhead entering the Skeena. The accuracy of catchability estimates that have historically been used for steelhead at Tyee is unknown, resulting in much uncertainty about the true number of steelhead migrating up the Skeena each year. To improve the accuracy of the Tyee catchability estimate, an innovative fish-tagging program has been proposed. This project, performed by Marc Labelle of L4 Biotech, uses simulation modeling to evaluate the potential costs and benefits of different implementations of the proposed tagging program. The report identifies the most cost-effective options and discusses tradeoffs between program cost and the levels of precision and accuracy that can be achieved.

project objectives
To evaluate ways to improve Skeena steelhead escapement estimates generated from the Tyee test fishery.
related documents

report: Evaluation of a mark-recapture procedure to assess the catchability rate of the Tyee test fishing gill-net

project timeline
May 22, 2009
to September 30, 2009
project lead
L4 Biotech
subjects
stock assessment
location
Skeena River Watershed, Tyee Test Fishery
related species
steelhead