See kokanee salmon at Sheep Creek

This year's Kokanee Salmon Day is set for September 22

MANILA - In the fall, biologists at Flaming Gorge Reservoir watch for flashes of bright red. But they aren't looking up at the trees - they're fisheries biologists watching the streams for the bright red flashes that indicate kokanee salmon are beginning their spawning runs up the tributary streams.

Utah's salmon populations are a completely freshwater species known as kokanee salmon. One of the most scenic kokanee runs in the state takes place in Sheep Creek, a tributary to Flaming Gorge about six miles south of Manila in northeastern Utah.

Kokanee Salmon
Kokanee salmon turn a bright red during their late summer spawning runs.
Photo by Ron Stewart

To mark the event, biologists from the Utah Division of Wildlife Resources will host Kokanee Salmon Day on Sept. 22. The event will be held at the Scenic Byway turnout where Sheep Creek flows under US-44.

The biologists will be on site from 9 a.m. to 3 p.m. to talk about this unusual fish and their remarkable spawning efforts. Displays will be set up to help viewers interpret the actions of the fish.

You may also want to bring binoculars or a spotting scope with you. Bighorn sheep are often visible from the viewing site or along the roads near Sheep Creek.

Salmon in Utah?

When people talk about salmon, it's usually about the dramatic runs Pacific salmon make into the rivers of the Northwest or Alaska, or maybe how good fresh or smoked salmon taste. Rarely do they talk about Utah's salmon runs. In fact, many people are surprised when they find out salmon live and breed in Utah.

The dramatic life cycles of the Pacific salmon have been well documented. Almost every child has seen television documentaries showing colorful red salmon fighting their way upstream through dams and past anglers, eagles, ospreys and bears. And all kids wonder why the salmon's struggles to breed in the gravel bars of fresh water streams should always result in their death. Thanks partially to those TV shows, salmon-run watching has become a major tourist attraction along the shores of many Western salmon rivers, including several in Utah.

Kokanee, a land-locked subspecies of the sockeye salmon, follow a similar life cycle. But instead of migrating downstream to the Pacific Ocean, they migrate to a fresh water lake. Kokanee are much smaller than their Pacific cousins. They probably don't create quite the dramatic pictures seen on TV, but the fish do turn red and fight their way upstream to breed and die.

Life cycle

A kokanee salmon is found in a stream for only two short periods - just after birth and just before it dies.

Its life starts as an egg, which its parents deposit in a nest they scraped out of the creek gravel in September or October. The egg hatches in December or January, and a young fish called an alevin emerges. The alevin still has part of its yolk sac attached. The alevin slowly absorbs its yolk sac while it hides in the gravel for its first few months of life.

After the yolk sack is absorbed, the young fish are known as fry. At this stage, they begin to emerge from the gravel to feed on microscopic plants and animals. When danger threatens, they return to the gravel and vegetation for cover.

The fry gain size and weight over the winter. By March and April, they're about one inch to one-and-a-half inches long. Spring runoff triggers the next stage. As the streams begin to swell with melted snow, the young fish (sometimes called parr or small fingerlings) begin to migrate, or maybe more accurately, be swept downstream to the reservoirs. Once in the reservoirs, the parr begin a more pelagic (open water) life, forming schools and feeding on floating, often microscopic, aquatic animals called zooplankton.

The schools of kokanee will follow the thermoclines of the water, clustering in the deeper 50 to 55 degree waters in the summer and winter months and using the surface waters in the fall and spring. The kokanee will spend about four years as a pelagic fish, foraging on zooplankton and growing in size until their biological clock tells them it's time to spawn.

The fish that survive the anglers and the natural hazards, such as lake trout, ospreys or sudden water quality changes, will be between 12 and 20 inches and weigh to 3 pounds when its time to spawn.

The spawning run

The early spawning runs begin in late August. The spawn reaches its peak in late September or early October. In August, spawning kokanee begin to change. The male develops a humped back and a hooked jaw, and both the male and the female begin to turn red from their head down. As these changes start to occur, they begin to stage in the reservoir where the streams enter. As the changes become more advanced, the fish begin their spawning run.

Anglers know that these physiological changes are also reflected in the quality of the salmon's meat. As the fish change and begin their run, they use up their fat reserves and begin to burn up the oils in their muscle. The meat eventually becomes mushy and has a poor flavor.

As their changes near completion, kokanee move toward the streams so they can get to the gravel bars to spawn. Some swim much farther than others as they search for the right combination of water and gravel. Biologists believe kokanee, like the sockeye salmon, also return to the gravel bar they hatched from, or close to it.

Once they've reached the gravel bar, the female picks the locations to build her nests. She will usually build several nests. Then she'll lay eggs in each one until she deposits all of her eggs. Female kokanee lay an average of 1,000 eggs.

The males fight for the right to fertilize a female's eggs. That's why the males have large jaws and a muscular, humped back. A male can fertilize eggs from more than one female, so the bigger, stronger males have the potential to be the most effective spawners.

Soon after spawning, the adults die, completing the cycle. Their bodies' decompose and fertilize the waters. That increases the plankton growth for the young fry as they start foraging for themselves. In four years, these young fry will be adult, mature salmon that will return to the creek to spawn.

Biologists have found that not all kokanee spawn in streams. Some populations use shale and gravel pockets on the banks inside a reservoir. Since quality stream habitat is limited, finding new areas to spawn can greatly enhance the total kokanee population in a reservoir. This inside-reservoir spawning has been a real bonus because these inside-reservoir spawning populations often become larger than those that risk the streams.