Idaho Lakes Teeming With Hatchery’s Juvenile Sockeye Broodstock Program A Hope For Endangered Salmon

Thousands of tiny fish, no more than four inches long, swim in the waters of central Idaho lakes and may hold the future to the survival of endangered sockeye salmon.

The Idaho Fish and Game last month dumped 53,000 juvenile sockeye salmon to buy time for the endangered Snake River run. The fish came from an intensive hatchery broodstock program that produced a half-million eggs in 1996-97.

Fish and Game biologist Paul Kline said hatchery workers placed about 22,000 sockeye fingerlings each into Redfish and Alturas lakes and 9,000 into Pettit Lake. The fish are expected to reside in the mountain lakes through the winter and migrate downstream toward the Pacific Ocean by next spring.

The Shoshone-Bannock Indian Tribal Fisheries Department has contributed to the Stanley Basin sockeye preservation effort through a program to improve water conditions for the rearing of young sockeye.

Tribal biologists are applying fertilizer to the three lakes to replace key nutrients that historically were generated by the annual post-spawning dieoff of thousands of salmon.

Kline said another 66,000 hatchery-raised fingerlings were placed in a netpen enclosure in Redfish Lake last month, to be released into open water in October.

The netpens are a series of fine-mesh nets in the water offshore. They serve as sort of a “halfway house” to acclimate the young salmon to life in the wild. The enclosures block out predator fish while allowing tiny aquatic animal life to pass through and serve as food for the young salmon.

During their stay in the netpens, the fish also receive pelleted feed.

Kline said separating the fish into various groups minimizes the chance of a disease outbreak, hatchery accident or other event wiping out the fish.

Redfish and Alturas lakes each will receive another 66,000 fingerlings in October.

Last November, 105,000 sockeye eggs were placed into special hatching boxes in Redfish Lake. Biologists expect 10,000 smolts.

Fish and Game also will place 87,000 sockeye smolts directly into Redfish Lake Creek and the upper Salmon River next May, with hope that instinct will push them seaward soon after release.

Subtracting expected losses from the thousands of sockeye that will have been stocked in Stanley Basin lakes by next spring, Kline said up to 150,000 smolts could head toward the Pacific Ocean in 1998.

If only one in 600 smolts successfully migrates to the ocean, grow to adult size and return to Idaho to spawn, that could mean more than 200 adult fish return to Idaho to spawn in 2000.

In recent years, only a handful of sockeye have completed the 700-mile trip.