2005 CHINOOK SALMON SONAR ENUMERATION ON THE BIG SALMON RIVER CRE-41-05. Prepared For: The Yukon River Panel Restoration and Enhancement Fund
Dates
Year
2006
Citation
Mercer, B., and Wilson, J. K., 2006, 2005 CHINOOK SALMON SONAR ENUMERATION ON THE BIG SALMON RIVER CRE-41-05. Prepared For: The Yukon River Panel Restoration and Enhancement Fund: J. Wilson & Associates: Whitehorse, Yukon, v. CRE-41-05, p. 25-25.
Summary
A long range dual frequency identification sonar (DIDSON-LR) was used to enumerate the chinook salmon escapement to the Big Salmon River in 2006, as well as determine associated run timing, and diel migration patterns. This was the second year of sonar operation at this site. The sonar site was located on the Big Salmon River at the same location as in 2005, approximately 1.5 km upstream of the confluence with the Yukon River. Partial weirs placed on both sides of the river were used to restrict fish passage through a 34 m opening. The sonar was configured to provide a 29º conical ensonified field, 40 m wide that covered the water column within the fish passage opening. A total of 7,308 (7,298 counted plus 10 extrapolated) targets [...]
Summary
A long range dual frequency identification sonar (DIDSON-LR) was used to enumerate the chinook salmon escapement to the Big Salmon River in 2006, as well as determine associated run timing, and diel migration patterns. This was the second year of sonar operation at this site. The sonar site was located on the Big Salmon River at the same location as in 2005, approximately 1.5 km upstream of the confluence with the Yukon River. Partial weirs placed on both sides of the river were used to restrict fish passage through a 34 m opening. The sonar was configured to provide a 29ยบ conical ensonified field, 40 m wide that covered the water column within the fish passage opening. A total of 7,308 (7,298 counted plus 10 extrapolated) targets identified as chinook salmon was counted past the sonar station between July 15 and August 23, 2006. A peak daily migration of 496 fish occurred on August 5, and 90% of the run had passed the station on August 12. The cumulative daily run pattern exhibited a normal distribution. The 2006 run timing was approximately 3 days later than was observed in 2005. The 2006 Big Salmon sonar project, as in the previous year, demonstrated that the DIDSON-LR sonar unit could produce observable images of fish swimming through the ensonified field at distances up to 40 m. At ranges >20 m, however, the resolution of target images was poor and the relative size of the targets beyond this distance could only be determined qualitatively. The results indicated that migrating chinook salmon were readily distinguishable from resident fish species by the relative size of the image and difference in swimming behaviour. The fish images produced total counts that correlated well with past chinook salmon passage data from the Big Salmon River and were concordant with the 2006 DFO derived upper Yukon River chinook escapement estimates. A carcass pitch was conducted over the total length of the Big Salmon River that yielded 234 chinook carcasses. Each carcass was sexed, and sampled for age determination, size and DNA analysis. Spaghetti tags were retrieved and the date of retrieval and tag number recorded. Of the 234 fish sampled, 110 (47%) were male and 124 (53%) were female. The mean fork length of males and females sampled was 825 mm and 891 mm, respectively. Ninety percent of the sampled fish were from the 1-3 and 1-4 age classes. A total of 5 spaghetti tags was collected. - from publication
