Snake River Sockeye Salmon Captive Broodstock Program; Hatchery Element, 2001 Annual Report.

Abstract

On November 20, 1991, the National Marine Fisheries Service listed Snake River sockeye salmon Oncorhynchus nerka as endangered under the Endangered Species Act of 1973. In 1991, the Idaho Department of Fish and Game, the Shoshone-Bannock Tribes, and the National Marine Fisheries Service initiated efforts to conserve and rebuild populations in Idaho. Initial steps to recover sockeye salmon included the establishment of a captive broodstock program at the Idaho Department of Fish and Game Eagle Fish Hatchery. Sockeye salmon broodstock and culture responsibilities are shared with the National Marine Fisheries Service at two locations adjacent to Puget Sound in Washington State. Activities conducted by the Shoshone-Bannock Tribes and the National Marine Fisheries Service are reported under separate cover. Idaho Department of Fish and Game monitoring and evaluation activities of captive broodstock program fish releases (annual report to the Bonneville Power Administration for the research element of the program) are also reported separately. Captive broodstock program activities conducted between January 1, 2001 and December 31, 2001 for the hatchery element of the program are presented in this report. In 2001, 26 anadromous sockeye salmon returned to the Sawtooth Basin. Twenty-three of these adults were captured at adult weirs located on the upper Salmon River and on Redfish Lake Creek. Three of the anadromous sockeye salmon that returned were observed below the Sawtooth Fish Hatchery weir and allowed to migrate upstream volitionally (following the dismantling of the weir on October 12, 2001). Nine anadromous adults were incorporated into the captive broodstock program spawning design in 2001. The remaining adults were released to Redfish Lake for natural spawning. Based on their marks, returning adult sockeye salmon originated from a variety of release options. Two sockeye salmon females from the anadromous group and 152 females from the brood year 1998 captive broodstock group were spawned at the Eagle Hatchery in 2001. Spawn pairings produced approximately 118,121 eyed-eggs with egg survival to eyed stage of development averaging 42.0%. Presmolts (106,166), smolts (13,915), and adults (79) were planted or released into Stanley Basin waters in 2001. Supplementation strategies involved releases to Redfish Lake, Redfish Lake Creek, Alturas Lake, and Pettit Lake. During this reporting period, five broodstocks and two unique production groups were in culture at Idaho Department of Fish and Game facilities (Eagle Fish Hatchery and Sawtooth Fish Hatchery). Two of the five broodstocks were incorporated into the 2001 spawning design, and one broodstock was terminated following the completion of spawning.