In the News

Kokanee Salmon Differ from Other Lake Tahoe Trout
date posted: December 22 2005

Lake Tahoe Report #86
Sept. 27, 2004
By John Cobourn and Heather Segale

One of Tahoe’s premiere annual outdoor spectacles is occurring this fall at the USDA Forest Service’s Taylor Creek Visitors Center, three miles northwest of South Lake Tahoe on California Route 89. The kokanee salmon have begun to spawn in Taylor Creek, and the Kokanee Salmon Festival will be held there 10 a.m. – 4 p.m., Oct. 2 – 3. At this family event, visitors will be able to view the bright red fish as they fill the creek in order to lay and fertilize their eggs. Forest Service biologists will stroll along the creek to explain the life cycle of the fish.

The kokanee salmon is actually the land-locked cousin of the sockeye salmon, which lives in the Pacific Ocean. The two fish are in the same genus and species, but the kokanee was introduced into Lake Tahoe in 1944. All Pacific salmon are anadromous, meaning that they are born in inland streams, live to adulthood in the ocean, and then return to the same freshwater stream to spawn, after which they die. Kokanee, on the other hand, have adapted to living their entire lives in fresh water. They spend their lives in the lake, and go up their home stream to spawn and die.

Salmon, including the kokanee salmon, are in the same biological family (salmonidae) as trout, whitefish, char, and grayling. The main difference between trout and Pacific salmon is that the trout live after spawning to spawn again.

The story of the kokanee salmon in Lake Tahoe is part of the history of commercial fishing in the first half of the 20th century. The two native trout in the lake were the Lahontan cutthroat trout and the mountain whitefish. The Lahontan cutthroat trout are now extinct in the Tahoe Basin due to over-fishing, dam-building, habitat destruction, and the introduction of nonnative aquatic species. Lake trout, called Mackinaws, from the Great Lakes were introduced, along with rainbow, brook and brown trout. Kokanee salmon were introduced as game and food fish. They also became forage fish for the large lake trout, which are now the top predators.

At present, kokanee salmon are suffering from the decline of their favorite food species, three native “water fleas,” two daphnia and a bosmina. The near-extinction of these tiny crustaceans was caused by the introduction of another small crustacean, the opossum shrimp, which ate the water fleas. Because of this, the average size of kokanees has declined in recent decades. Nevertheless, about 99 percent of kokanee spawning still occurs in Taylor Creek, and their abundance has made the fall festival a popular event.

Kokanee salmon generally spawn and die two to three years after they hatch and swim out into the lake. Each autumn, adult males develop a humped back and a heavy, hooked jaw, equipping them for the inevitable battles over both mates and territory. Both sexes turn from their usual silver-blue color to a brilliant red. Then, over a period of several weeks, the fish migrate to their mating grounds. The salmon fight their way up the shallow stream, displaying their colors to attract a mate. They then battle to protect the small patch of gravel streambed where they make their “redds” or nests and lay their eggs. Other trout also spawn in Tahoe creeks, such as the spring-spawning rainbows and the fall-spawning German browns. These fish spawn in Taylor Creek and other streams suitable for their needs.

The Taylor Creek Visitors Center gives students and other visitors a chance to see large numbers of salmon in the creek, both from above and the water. The stream profile chamber allows people to look through a glass wall right into the channel where the fish are spawning. During October, 100 to 150 children come each day from surrounding communities on school field trips to learn about the salmon. This year, perhaps due to the early September cold snap, the spawning began a little early, on Sept.18. It should continue through the month of October. For details about the festival, contact the Lake Tahoe Visitor Center at Taylor Creek, (530) 543-2674.