Category: Fish/Shellfish Research
Published: May 2008
Author(s): Jeremy Trump and Glen Mendel, WDFW
The Snake River recreational chinook fishery opened May 9th and ran through June 30th, 2007. 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 78,500 spring/summer Chinook. The Pre-season plans for the Snake River recreational chinook fishery was to harvest up to 292 hatchery adult spring chinook, with an allowable Endangered Species Act (ESA) impact of 15 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 151 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.
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 (counts were done four times a day). Creel surveys consisted of â€�"early creelâ€ or â€�"late creelâ€ in an attempt to shorten day length for creel clerks, but still effectively monitor the fishery. Early creel had count times at 7:00am, 10:00am, 1:00pm, and 4:00pm, and late creel had count times at 10:30am, 1:30pm, 4:30pm, and 7:30pm. After each count interviews of anglers were conducted until it was time for the next count. Monitoring was conducted at least one weekday and one weekend day per 7 day period, with each two week period containing one early and one late creel for weekday and weekend categories. Creel surveys were conducted on 15 days (8 weekdays and 7 weekend days) of the season. The 53 day fishery had 37 weekdays and 16 weekend days available. We included Monday May 28th (Memorial Day) as a weekend day since it was a holiday. We sampled 21.6% of weekdays and 43.8% of weekend days. Survey data were summarized bi-weekly to average early and late creel for both weekdays and weekends. These two week averages were used 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.