Adult Sockeye Salmon Released to Redfish Lake

On September 7, 2005 program managers for the Redfish Lake Sockeye Salmon Captive Broodstock Program completed one of their annual fish reintroduction activities. Workers released 173 sockeye into Redfish Lake to spawn naturally. Adult release is one of five strategies used to return fish to the wild. All adults released on September 7 were reared by NOAA Fisheries in Manchester, Washington. The 173 adults released represent maturing sockeye from brood years 2000, 2001, and 2002 (age-3 through age-5 fish). Six captive-reared sockeye received radio transmitters before release to allow research biologists to monitor spawning behavior. Snake River sockeye salmon Oncorhynchus nerka were listed as Endangered under the U.S. Endangered Species Act in 1991. Conservation experts have described Snake River sockeye salmon as a prime example of a species on the threshold of extinction. In Idaho, the lakes of the upper Salmon River represent the only potential habitat for sockeye salmon. Historically, five Sawtooth Valley lakes (Redfish, Alturas, Pettit, Stanley, and Yellow Belly) supported sockeye. By 1962, sockeye salmon were no longer returning to Stanley, Pettit, and Yellow Belly lakes. Currently, only Redfish Lake receives a remnant run of sockeye returning from the Pacific Ocean; between 1990 to 1998, only 16 wild adults returned to Redfish Lake. Snake River sockeye salmon travel the longest distance (900 miles one way) and to the highest elevation (almost 7,000 ft) of any population of sockeye salmon in the world. In addition, they are the most southerly population of sockeye salmon in the world. Due to the precipitous decline of returning anadromous adults, the Idaho Department of Fish and Game began the Snake River Sockeye Salmon Captive Broodstock Program in 1991. The program generates hatchery-produced eggs, juveniles, and adults for reintroduction to Sawtooth Valley waters. Genetically diverse broodstocks remain in the hatchery to supplement the fish that migrate to and from the ocean. The reintroduction plan follows a "spread-the-risk" philosophy. Progeny from the captive broodstock program are reintroduced to Sawtooth Valley waters at different life stages using a variety of release options including: 1) eyed-egg plants to in-lake incubator boxes, 2) presmolt releases direct to lakes, 3) presmolt transfers to net pens for in-lake rearing and release in Redfish Lake, 4) smolt releases to the outlet of Redfish Lake and to the upper Salmon River and 5) adult releases directly to lakes. All sockeye salmon spawning and early rearing is conducted at the IDFG Eagle Fish Hatchery and at NOAA Fisheries facilities in Washington State. Juveniles produced from in-lake spawning will begin migrating downstream toward the Pacific primarily as one year old smolts in 2007. Adults could return to Redfish Lake as early as 2009. The program is coordinated by the Stanley Basin Sockeye Technical Oversight Committee, a team of biologists representing the Idaho Department of Fish and Game, the Shoshone-Bannock Tribes, the National Oceanic and Atmospheric Administration (NOAA), and the University of Idaho. The Bonneville Power Administration is the coordinating and funding agency for Snake River sockeye salmon recovery actions.