Captive Rearing Program for Salmon River Chinook Salmon. Annual Report 2002.

Venditti, D. A. ; Willard, C. ; Looney, C. ; Sline, P.

Technical Information Center Oak Ridge Tennessee

关键词: Salmon;    Fisheries;    Idaho;    Salmon river;    Chinhook salmon;   

RP-ID  :  DE2004820048

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

During 2000, the Idaho Department of Fish and Game (IDFG) continued to develop techniques to rear chinook salmon Oncorhynchus tshawytscha to sexual maturity in captivity and to monitor their reproductive performance under natural conditions. Eyed-eggs were collected to establish captive cohorts from three study streams and included 503 eyed-eggs from East Fork Salmon River (EFSR), 250 from the Yankee Fork Salmon River, and 304 from the West Fork Yankee Fork Salmon River (WFYF). After collection, the eyed-eggs were immediately transferred to the Eagle Fish Hatchery, where they were incubated and reared by family group. Juveniles collected the previous summer were PIT and elastomer tagged and vaccinated against vibrio Vibrio spp. and bacterial kidney disease before the majority (approximately 75%) were transferred to the National Marine Fisheries Service, Manchester Marine Experimental Station for saltwater rearing through sexual maturity. Smolt transfers included 158 individuals from the Lemhi River (LEM), 193 from the WFYF, and 372 from the EFSR. Maturing fish transfers from the Manchester facility to the Eagle Fish Hatchery included 77 individuals from the LEM, 45 from the WFYF, and 11 from the EFSR. Two mature females from the WFYF were spawned in captivity with four males in 2000. Only one of the females produced viable eggs (N = 1,266), which were placed in in-stream incubators by personnel from the Shoshone-Bannock Tribe. Mature adults (N = 70) from the Lemhi River were released into Big Springs Creek to evaluate their reproductive performance. After release, fish distributed themselves throughout the study section and displayed a progression of habitat associations and behavior consistent with progressing maturation and the onset of spawning. Fifteen of the 17 suspected redds spawned by captive-reared parents in Big Springs Creek were hydraulically sampled to assess survival to the eyed stage of development. Eyed-eggs were collected from 13 of these, and survival ranged from 0% to 96%, although there was evidence that some eggs had died after reaching the eyed stage. Six redds were capped in an attempt to document fry emergence, but none were collected. A final hydraulic sampling of the capped redds yielded nothing from five of the six, but 75 dead eggs and one dead fry were found in the sixth. Smothering by fine sediment is the suspected cause of the observed mortality between the eyed stage and fry emergence.