Enumeration of Salmonids in the Okanogan Basin Using Underwater Video, Performance Period: October 2005 (Project Inception) - 31 December 2006.

Johnson, Peter N. ; Rayton, Michael D. ; Nass, Bryan L. ; Arterburn, John E.

Bonneville Power Administration (BPA), Portland, OR

关键词: Abundance;    Adults;    Monitoring;    Salmon;    Rivers;   

DOI  :  10.2172/949218
RP-ID  :  P105814
RP-ID  :  31582
RP-ID  :  949218

美国|英语

来源: UNT Digital Library

【 摘 要 】

The Confederated Tribes of the Colville Reservation (Colville Tribes) identified the need for collecting baseline census data on the timing and abundance of adult salmonids in the Okanogan River Basin in order to determine basin and tributary-specific spawner distributions, evaluate the status and trends of natural salmonid production in the basin, document local fish populations, and augment existing fishery data. This report documents the design, installation, operation and evaluation of mainstem and tributary video systems in the Okanogan River Basin. The species-specific data collected by these fish enumeration systems are presented along with an evaluation of the operation of a facility that provides a count of fish using an automated method. Information collected by the Colville Tribes Fish & Wildlife Department, specifically the Okanogan Basin Monitoring and Evaluation Program (OBMEP), is intended to provide a relative abundance indicator for anadromous fish runs migrating past Zosel Dam and is not intended as an absolute census count. Okanogan Basin Monitoring and Evaluation Program collected fish passage data between October 2005 and December 2006. Video counting stations were deployed and data were collected at two locations in the basin: on the mainstem Okanogan River at Zosel Dam near Oroville, Washington, and on Bonaparte Creek, a tributary to the Okanogan River, in the town of Tonasket, Washington. Counts at Zosel Dam between 10 October 2005 and 28 February 2006 are considered partial, pilot year data as they were obtained from the operation of a single video array on the west bank fishway, and covered only a portion of the steelhead migration. A complete description of the apparatus and methodology can be found in 'Fish Enumeration Using Underwater Video Imagery - Operational Protocol' (Nass 2007). At Zosel Dam, totals of 57 and 481 adult Chinook salmon were observed with the video monitoring system in 2005 and 2006, respectively. Run timing for Chinook in 2006 indicated that peak passage occurred in early October and daily peak passage was noted on 5 October when 52 fish passed the dam. Hourly passage estimates of Chinook salmon counts for 2005 and 2006 at Zosel Dam revealed a slight diel pattern as Chinook passage events tended to remain low from 1900 hours to 0600 hours relative to other hours of the day. Chinook salmon showed a slight preference for passing the dam through the video chutes on the east bank (52%) relative to the west bank (48%). A total of 48 adult sockeye salmon in 2005 and 19,245 in 2006 were counted passing through the video chutes at Zosel Dam. The 2006 run timing pattern was characterized by a large peak in passage from 3 August through 10 August when 17,698 fish (92% of total run observed for the year) were observed passing through the video chutes. The daily peak of 5,853 fish occurred on 4 August. Hourly passage estimates of sockeye salmon counts for 2005 and 2006 at the dam showed a strong diel pattern with increased passage during nighttime hours relative to daytime hours. Sockeye showed a strong preference for passing Zosel Dam on the east bank (72%) relative to the west bank (28%). A total of 298 adult upstream-migrating steelhead were counted at Zosel Dam in 2005 and 2006, representing the 2006 cohort based on passage data from 5 October 2005 through 15 July 2006. Eighty-seven percent (87%) of the total steelhead observed passed the dam between 23 March and 25 April with a peak passage occurring on 6 April when 31 fish were observed. Steelhead passage at Zosel Dam exhibited no diel pattern. In contrast to both Chinook and sockeye salmon, steelhead were shown to have a preference for passing the dam on the west bank (71%) relative to the east bank (29%). Both Chinook and sockeye passage at Zosel Dam were influenced by Okanogan River water temperature. When water temperatures peaked in late July (daily mean exceeded 24 C and daily maximum exceeded 26.5 C), Chinook and sockeye counts went to zero. A subsequent decrease in water temperature resulted in sharp increases in both Chinook and sockeye passage. A total of six steelhead were observed with the video monitoring system at Bonaparte Creek in 2006, with three passage events occurring on 29 March and one each on 20, 21, and 23 April. This system was operational for only a portion of the migration.