| Abstract/Description or Keywords |
During the summer and fall of 2009, Wet’suwet’en Fisheries continued the Moricetown Canyon steelhead tagging program that was initiated in 1999, in coordination with an ongoing coho, sockeye and chinook tagging program. Coho, sockeye and chinook data were analysed separately by Fisheries and Oceans Canada. The data collected for steelhead migration from July 27th to October 1st in 2009 and are summarized in this report. The continued objectives of this steelhead tagging program have been to standardize the sampling methodologies, to evaluate in-season population estimates or indices and to monitor the run-timing and relative returns of steelhead migrating upstream of Moricetown Canyon. In 2009, 1390 steelhead were marked by beach seining downstream of Moricetown Canyon (i.e. campground) and 2297 steelhead, including 127 recaptures were handled at Moricetown Canyon for census. Tagging at the campground ended on September 25th, and tagging effort was reduced by one crew from September 22nd to September 25th. Sampling by dip net at the canyon ended on October 1st, but was reduced to one crew on September 21st. The Schaeffer estimate for steelhead abundance at Moricetown Canyon up to October 1st is 23,986 steelhead and the Maximum likelihood Darroch estimate for is 23,886 steelhead (95% confidence interval = 14,639-33,133). For comparison of 2009 abundance to historical records, the adjusted Petersen estimate for 2009 was also calculated and comes to 24,973 with a 95% confidence interval from 21,578 to 30,112. This estimate was only the fifth highest estimate since 1999, but is well within the 95% lower confidence interval of all the other higher estimates. However, this Petersen estimate is significantly greater than the Petersen estimates for 2003, 2005, and 2006 (i.e. 12150, 15341, and 15138) which suggest that the general ranking of this abundance is moderate and potentially high. These estimates should be viewed in light of constraints of the study, including low recapture rates (2.8%), and non-random sampling at the beach seine and dipnet locations. The estimated number of steelhead moving through Moricetown Canyon in the study period is the highest estimate since 2001, when the numbers of recaptures increased from very low initial recapture rates in 1999 and 2000. |
