Kokanee salmon run the river

The streams above Porcupine Dam were bursting with brightly colored kokanee salmon as they performed their yearly salmon run, filling the river beds with eggs. This is a tradition that will be continued by their offspring for as long as they live in the Porcupine Reservoir.   

Timothy Walsworth is an assistant professor of fish ecology and fisheries management in the Department of Watershed Sciences and the Ecology Center at Utah State University.

“Porcupine Reservoir hosts a run of kokanee salmon, which are the landlocked form of sockeye salmon (Oncorhynchus nerka),” Walsworth wrote in an email to The Utah Statesman. “While sockeye salmon are anadromous and move between freshwater and marine habitats during different life stages, kokanee salmon remain in freshwater throughout their life.”

The kokanee salmon in the Porcupine Reservoir are landlocked because they don’t have access to the ocean. They can only lay their eggs in the stream connected to the reservoir. 

According to Walsworth, the kokanee salmon are not naturally a part of Utah’s lakes and reservoirs.

“Kokanee salmon are not native to Utah, but were introduced to provide sport fishing opportunities. They are native to lakes in the Pacific Northwest (Oregon, Washington, British Columbia, Alaska), as well as in parts of Russia and Japan,” Walsworth wrote.

While the kokanee salmon can be fished for sport in the reservoir, they cannot be fished or harassed during their spawning season.

Autumn Zierenberg is studying fisheries and aquatic sciences at USU.

“It is perfectly fine to go spectate, however, it is illegal to harass the fish while spawning. Harassment includes wading through the river, letting dogs chase them, and any behaviors that might stress the salmon. It is also illegal to fish them from September 30th to November 30th,” Zierenberg wrote in an email to The Utah Statesman.

According to Walsworth, the kokanee salmon’s traditional spawning period is from September to October.

“The Utah Division of Wildlife Resources notes that peak spawning time is usually in the middle of September,” Walsworth wrote.

The kokanee salmon differ from traditional sockeye salmon because they are potamodromous, not anadromous.

“Sockeye salmon are anadromous, meaning they migrate from freshwater to saltwater as young to feed and grow, then migrate back to freshwater to spawn and then die,” Zierenberg wrote. “This life cycle for kokanee mirrors the sockeye life cycle as the fish exhibit potadromy (freshwater to freshwater migration).”

The kokanee salmon’s lifespan is around four years. In the last year of their lives, they travel upstream from a lake or reservoir and lay their eggs in the riverbed where they die. Their nutrients feed the plants and animals within the stream that rely on the fish.

They travel upstream for two major reasons: to provide oxygen for their eggs and to follow their instincts.

“Since it is upstream it is conducive to the salmon’s natural instinct to migrate up river. It is also one of the only tributaries to flow into porcupine,” Zierenberg wrote.

According to Walsworth, kokanee salmon lay their eggs in the stream to make sure they receive oxygen.

“Kokanee salmon spawn in streams where they can dig nests called redds to lay and bury their eggs. The water flowing over and through their redds provide oxygen to the eggs, allowing them to develop into the next generation of Kokanee salmon,” Walsworth wrote.

During the kokanee’s spawning season, they change color from gray to bright red. 

Walsworth wrote that the kokanee salmon turn red due to certain pigments in their diet that move to their skin when they get ready to spawn.

“These pigments give Kokanee and sockeye salmon their bright red color, and serve as a signal to potential mates of an individual salmon’s fitness,” Walsworth wrote.

If anyone wishes to see the kokanee salmon upstream from the Porcupine Reservoir, it is important that they are following the regulations set in place to protect the salmon and the fish are not disturbed during their spawning season.

“Those interested in visiting the salmon run should check with the Utah Division of Wildlife Resources for specific regulations. You are allowed to visit Porcupine Reservoir and watch the salmon in the East Fork of the Little Bear River, though you need to be careful about trespassing,” Walsworth wrote.

Specific areas around the stream are acceptable spots for viewing the fish during their spawning season

“In most years, reservoir levels drop enough that the stream extends into the land occupied by the reservoir under higher water conditions. This area at the east end of the reservoir is a great place to observe the Kokanee migration and spawning, but there is private land just upstream that you need to be careful not to trespass on without permission from the landowners,” Walsworth wrote.