by Alaska Dept. of Fish and Game, Division of Sport Fish in Anchorage, Alaska .
Written in English
The abundance of medium and large chinook salmon Oncorhynchus tshawytscha that returned to spawn in the Unuk River in 1997 was estimated using a mark-recapture experiment. Fish were captured in the lower Unuk River using set gillnets from June through July, and each healthy fish was individually marked with a solid-core spaghetti tag sewn through its back and was given two secondary marks in the form of an upper-left operculum punch and removal of the left axillary appendage. Spawning grounds sampling took place from July through August to estimate the fraction of the escapement that had been marked. During this study, 404 chinook salmon were captured in the lower Unuk River, and 382 of these were marked and released alive. Three hundred seven (307) fish were considered large (660 mm mid-eye to fork [MEF]) and 75 were considered medium (401659 mm MEF) in size. At the spawning grounds, 965 fish were sampled; 761 were considered large fish, and of these, 78 were recaptures which had been previously marked in the lower river with spaghetti tags. One hundred fifty-six (156) medium fish were sampled, and 16 of these were recaptures. A modified Petersen model was used to estimate that 2,970 (SE = 277, M = 307, C = 761, R = 78) large, 701 (SE = 158, M = 75, C = 156, R = 16) medium, and 3,671 (SE = 320) fish >400 mm MEF in length immigrated into the Unuk River in 1997. An estimated 32% of this immigration was sampled during the project. Peak survey counts in August totaled 636 large chinook salmon, about 21% of the mark-recapture estimate of large fish, a trend seen in similar studies. Of the spawning population >400 mm MEF, 38% were estimated to be age-1.4 fish from the 1991 brood year, 34% were estimated to be age-1.3 fish, and 25% were estimated to be age-1.2 fish.
|Statement||by Edgar L. Jones III, Scott A. McPherson and David L. Magnus.|
|Series||Fishery data series -- no. 98-23.|
|Contributions||McPherson, Scott A., Magnus, David L., Alaska. Division of Sport Fish.|
|The Physical Object|
|Pagination||ii, 35 p. :|
|Number of Pages||35|
Coupled with aerial surveys, a mark-recapture study takes place annually to estimate the spawning abundance of Chinook salmon in the Unuk River. Since , abundance has ranged between large fish, with an average of 4, large fish. Mark-recapture estimates of escapements of masu salmon in a small river. A Mark-Recapture Experiment to Estimate the Escapement of Chinook Salmon in the Unuk River, Elk River hatchery stock has a continuous history of CW-tagged fish released and a continuous monitoring program to estimate the terminal run. A mark-recapture experiment conducted in serves as the calibration for development of 2 predictive models to estimate the run for both wild and hatchery origin chinook. The Skeena River is host to the second largest aggregate of Chinook salmon in British Columbia. While the aggregate is a PSC escapement indicator stock, there are no biologically based escapement goals for this population.
survey lives for male (telemetry) and female (telemetry and tower observation) chinook salmon in the Lower Shuswap River. Mark-recapture based survey lives were directly estimated by dividing the mark-recapture escapement estimate by the AUC estimate of total spawner days. Observer efficiency was estimated by comparing observer counts. Estimating Salmon Spawning Escapement Using Capture–Recapture Methods Article (PDF Available) in Canadian Journal of Fisheries and Aquatic Sciences 50(6) . Mark-recapture experiment for the Chinook salmon spawning escapement in the Atnarko River Technical Report (PDF Available) January with 83 Reads How we measure 'reads'. Figure 18 summarizes the various estimates of escapement. Mark-recapture Chinook Salmon Escapement The mark-recapture was the largest estimate of escapement annually (Table 18 and Figure 18). Previous studies have shown that closed population Petersen mark-recapture method often exhibits a positive bias (Cousens et al., ) caused by File Size: 1MB.
Mark-Recapture Experiments to Estimate the Abundance of Fish A Short Course Given by the Division of Sport Fish Alaska Department of Fish and Game in David R. Bernard and Patricia A. Hansen November Alaska Department of Fish and Game Division of Sport Fish ˜is document was revised 10/30/; See corrected pa 22, and The objectives of the upper Sacramento River fall-run chinook salmon escapement survey were: # To estimate the , in-river, fall-run chinook salmon spawning population for the upper Sacramento River upstream of Cottonwood Creek. # To evaluate egg-retention, and sex and age composition of fall-run chinook salmon. Escapement and Productivity of Spring Chinook Salmon and Summer Steelhead in the John Day River Basin Annual Technical Report December 1, –Novem Prepared by. A MARK-RECAPTURE EXPERIMENT TO ESTIMATE THE ABUNDANCE OF KUSKOKWIM RIVER SOCKEYE, CHUM, AND COHO SALMON, By Carol M. Kerkvliet Jason Pawluk Toshihide Hamazaki Karen E. Hyer and David Cannon Regional Information Report No. 1/ 3A Alaska Department of Fish and Game Commercial Fisheries Division, AYK Region .