Nature Center Gets New Fish

Only a few hours from the river and still full of energy from their spawning drive, four Chinook salmon arrived at the Morrison Knudsen Nature Center Tuesday afternoon, July 17. Four Chinook salmon were delivered to the Nature Center's Alpine Lake, two 3-year-old males, called jacks; and two females, 4- and 5-year-olds based on their length. Jacks spend one year in the ocean, while adult females have spent two to three years in the ocean. It is extremely rare anymore for Chinook to reach 6 years old. And it is also rare for females to return as 3-year-olds. They need size to carry 3,500 to 7,500 eggs. These fish were caught in the department's salmon trap on the South Fork of the Salmon River east of Cascade, about 740 miles inland and about 5,000 feet above sea level. Before they headed upriver, they had traveled thousands of miles in the ocean. The fish left Idaho as juveniles-the 5-year-old female in 2004, the 4-year-old female in 2005 and the two males in 2006. Adult salmon smell their way back to the streams where they were hatched. Somehow they record and replay the smells of the trip to the ocean. The fish delivered to the Nature Center are hatchery fish, identified as such by having their adipose fins clipped before they were released as smolts. This identifies them as fish that may be harvested under state fishing regulations and management. Most of Idaho's Chinook hatcheries were built to supply fish for fisheries, not to replace wild fish. These fish are surplus to hatchery needs for the hatchery program. Wild fish with adipose fins present must be released unharmed if they are caught. All native, wild runs of Idaho salmon and steelhead are at risk of extinction, either listed as endangered or threatened under the Endangered Species Act. Idaho's coho salmon are extinct. The Boise River once was home to native anadromous fish. The Hells Canyon complex of hydroelectric dams extirpated runs in this part of the Snake River drainage. The newly arrived fish probably will spawn at the Nature Center between mid-August and early September. There are three generations of Chinook at the Nature Center: juveniles from last year, the newly arrived adults, and the next generation yet to be spawned. The fish can be viewed through the large windows into the underwater world of the Alpine Lake of the Nature Center's Stream Walk.