Snake River Sockeye Salmon Captive Broodstock Program; Hatchery Element, 1999 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 are also reported under separate cover. Captive broodstock program activities conducted between January 1, 1999 and December 31, 1999 are presented in this report. In 1999, seven anadromous sockeye salmon returned to the Sawtooth Valley and were captured at the adult weir located on the upper Salmon River. Four anadromous adults were incorporated in the captive broodstock program spawning design for year 1999. The remaining three adults were released to Redfish Lake for natural spawning. All seven adults were adipose and left ventral fin-clipped, indicating hatchery origin. One sockeye salmon female from the anadromous group and 81 females from the captive broodstock group were spawned at the Eagle Fish Hatchery in 1999. Spawn pairings produced approximately 63,147 eyed-eggs with egg survival to eyed-stage of development averaging 38.97%. Eyed-eggs (20,311), presmolts (40,271), smolts (9,718), and adults (21) were planted or released into Sawtooth Valley waters in 1999. Supplementation strategies involved releases to Redfish Lake, Redfish Lake Creek, upper Salmon River (below the Sawtooth Fish Hatchery weir), Alturas Lake, and Pettit Lake. During this reporting period, four broodstocks and three production groups were in culture at the Eagle Fish Hatchery. Two of the four broodstocks were incorporated into the 1999 spawning design and one broodstock was terminated following the completion of spawning.