Summary report of Bulkley/Morice River steelhead data collected by the Wet’suwet’en Fisheries during the 2012 Moricetown Tagging Project

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Summary

Since 1999, the Moricetown Salmon Tagging Project has been conducted on the Bulkley River by the Wet’suwet’en Fisheries and Fisheries and Oceans Canada, with the inclusion of data collection for steelhead (Oncorhynchus mykiss) under assistance from the Skeena Fish and Wildlife Branch of the British Columbia Ministry of Forests, Lands and Natural Resource Operations, the Pacific Salmon Foundation, and the British Columbia Living Rivers Trust Fund. This mark and recapture project has involved sampling by beach seine for tag application immediately downstream of Moricetown Canyon (i.e. referred to as “campground”) and re-sampling by dip net at the base of Moricetown Falls and fishway (i.e. referred to as “canyon”). In 2012, steelhead catch at both the campground and at the canyon were respectable in comparison to the earlier years of this study, but somewhat lower than the highest year (i.e. 2010) as a result of fewer steelhead arriving and reduced sampling effort due to budget constraints. Of the 2890 steelhead that were examined at the canyon, 125 were recaptures of the 1196 steelhead tagged at the campground. The stratified abundance estimates for steelhead arriving at Moricetown from July 30th to October 18th, with a 2.5% correction for tag loss, were 21 926 (95% C.I. 16 456 – 27 395) using Maximum Likelihood Darroch and 22 931 using Schaefer methods. The stratified abundance estimates are provided to identify potential inaccuracies, bias and misleading precision of an estimate of 27 465 steelhead (95% C.I. 23 709 – 33 167) using the pooled Petersen estimate for inter-annual comparisons of steelhead abundance to previous years. In general, the pooled Petersen estimate for steelhead abundance in 2012 was significantly lower than the highest and most precise estimate of steelhead arriving at Moricetown in 2010 (i.e. 41 140 with 95% C.I.: 38 058 – 44 934) and significantly higher than estimates made for 2003, 2004, 2005, 2006, and 2011.

–Excerpt from the report’s Executive Summary

The appendices to this report can be found here.