Snake River Spring Chinook Salmon Fishery Report, 2006

This 2006 harvest monitoring summary is for the sixth consecutive year of spring chinook fisheries in the Snake River in southeast Washington (first year was 2001). The Snake River recreational chinook fishery opened May 17 and ran through June 30, 2006. The Snake River was open from the Texas Rapids boat launch upstream to the Corps of Engineers boat launch (approximately one mile) upstream of Little Goose Dam on the south bank of the river; referred to as the Little Goose (LGO) fishery in this report. The fishery was open seven days per week, with daily fishing hours set from one hour before sunrise to one hour after sunset. The daily limit consisted of one hatchery (adipose fin-clipped) chinook salmon (adult or jack) per day, with a minimum size of 12 inches. Anglers were required to use barbless hooks, with hooks of no more that 5/8-inch from point to shank.

The pre-season forecast for upriver spring chinook was estimated (entering the mouth of the Columbia River) at 88,400 spring/summer Chinook. The Pre-season plans for the Snake River recreational chinook fishery was to harvest up to 876 hatchery adult spring chinook, with an allowable Endangered Species Act (ESA) impact of 29 wild fish mortalities (0.2% ESA impact on wild chinook estimated at Columbia River mouth). Assuming a 10% mortality rate on released fish, this allowed for 292 wild adult encounters. ESA impacts for this fishery are included as part of the non-Indian rate of 2.0% allowable impact which also includes recreational and commercial fisheries downstream. However, the run came in at a higher rate than expected from pre-season estimates. An in-season estimate on May 22nd updated the adult upriver spring chinook forecast to 125,000 fish based primarily on counts at Bonneville Dam. Another estimate in the middle of June again increased the number to 130,000, with 67,864 of these fish entering the Snake River. This increased the amount for a harvest (at 0.2% ESA impact on wild chinook estimated at Columbia River mouth) to 1,287 hatchery chinook adults and increased the number of encounters (or �"handle”) of wild chinook adults to 429. Total ESA impact for this fishery was expected to be 43 wild adult mortalities or an impact rate of approximately 0.20%.

The Washington Department of Fish and Wildlife monitored the fishery using a roving creel survey which included: boat ramp and shore interviews to collect catch rate, completed trip and biological information; and effort counts of shore anglers, boat anglers, and the number of boats (angler effort counts were conducted five times a day). Monitoring was conducted at least one weekday and one weekend day per 7 day period, utilizing a dawn to dusk survey format. Creel surveys were conducted on 15 days (6 weekend days and 9 weekdays) of the season. The 45-day fishery had 32 weekdays and 13 weekend days available. We included Monday May 29th (Memorial Day) as a weekend since it was a holiday. We sampled 46.2% of weekend days and 28.1% of weekdays. Survey data were summarized weekly to estimate number of fish harvested, released, and total encounters (harvested and fish released), and to assure compliance with the ESA impact level that had been set for the fishery.