Category: Fish

A highly compelling mating drama is taking place now in select mountain reservoirs. Utah’s colorful kokanee salmon are at the very peak of their upstream migration. Yearning to find the gravel bar in which they were born, these fish follow their noses. For the smell of that gravel birthplace–and the surrounding stream–is imprinted in young kokanee brains. Biologists call this smell the “home stream olfactory bouquet.”

Once a female kokanee is satisfied with the surrounding “olfactory bouquet,” she digs a nest in the gravel with her tail. As she digs one or more of these nests, individual males will try to guard her in order to secure their paternity. Part of the spectacle of kokanee-watching comes from the darting and biting and jostling among males attempting to get access to females. Once the eggs are laid and fertilized the female covers them with gravel.

This is the end of the line for the new parents. Within a few days of egg laying the female will die. And the male will follow soon after. Expired fish provide food for predators and scavengers such as gulls, ravens, and coyotes. Any leftover salmon will decompose and fertilize the stream waters, leading to plankton growth, which—in turn–will nourish the new crop of young salmon.

In Utah, kokanee eggs hatch between November and January. The tiny new salmon will spend their first weeks of life hiding in the gravel feeding off the remains of their egg yolk sack. After a few weeks they will emerge from the gravel to feed on plankton. By spring, these youngsters—called fingerlings– will be an inch and a half long. During spring runoff the fingerlings are swept downstream until they spill into a lake or reservoir. Now they will stay here in the open water for 2-4 years, feeding on zooplankton until they reach maturity.

For these first stages of life kokanee are dark to greenish blue on the head and back, silver on the sides and silvery or white underneath.
But at summer’s end, the spawning salmon will undergo their astonishing transformation. The males’ bodies will turn a bright red-orange. Their shape will change as well. They will acquire humped backs, hooked jaws, and elongated teeth. The females also turn red although the color may not be as striking. By late August both males and females are congregating at the mouth of the spawning stream preparing to embark on the final–and most important–mission of their lives.

For more information and locations for kokanee viewing go to www.wildaboutUtah.org. You’ll also see a video of kokanee spawning in the Little Bear River*, the main tributary of Porcupine Reservoir.

For Wild About Utah, I’m Holly Strand.

* Many people call this Cinnamon Creek. However the Little Bear River feeds Porcupine reservoir. Cinnamon creek joins the Little Bear, as a tributary, a little bit up stream and East of Porcupine reservoir.

Credits:

Photo: Courtesy and Copyright 2008 Mary-Ann Muffoletto, Photographer
Video: Courtesy and Copyright 2013 Charles Hawkins, Photographer
Video: Courtesy and Copyright 2013 Holly Strand, Photographer
Text: Holly Strand, Quinney College of Natural Resources at Utah State University

Where to see kokanee salmon spawning (adapted from Utah Div. of Wildlife Resources website)

The Kokanee spawning runs in Sheep Creek, Indian Creek, Strawberry River and the upper East Fork Little Bear River occur in late August through early October. Flaming Gorge Reservoir has a late-season spawning population which spawns in the Green River and along the shores of the reservoir in late October through November.

Sheep Creek is in northeastern Utah, about six miles south of Manila. The viewing site is at the Scenic Byway turnout where Sheep Creek crosses under state Route 44.

Porcupine Reservoir: Just pass Avon, turn left (there’s a sign) and head east to the reservoir. Pass the dam and follow the shelf road past the end of the reservoir. There will be a wide level area where you can park and walk down to the Little Bear River to see the salmon.

Sept. 22 is Kokanee Salmon Viewing Day.at the U.S. Forest Service visitor center at Strawberry Reservoir. Utah Div. of wildlife Biologists will be on hand to show you the salmon and answer any questions. https://wildlife.utah.gov/dwr/news/42-utah-wildlife-news/906-see-kokanee-at-strawberry.html Even if you can’t make it to this event, salmon should be visible in the Strawberry River, and other tributaries to Strawberry, from now until the first part of October.

Sources & Additional Reading

Sept. 22 is Kokanee Salmon Viewing Day.at the U.S. Forest Service visitor center at Strawberry Reservoir. Utah Div. of wildlife Biologists will be on hand to show you the salmon and answer any questions.
https://wildlife.utah.gov/dwr/news/42-utah-wildlife-news/906-see-kokanee-at-strawberry.html [Accessed September 19, 2013]

Resources:
Fuller, P., G. Jacobs, J. Larson, and A. Fusaro. 2013. Oncorhynchus nerka. USGS Nonindigenous Aquatic Species Database, Gainesville, FL.
https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=915 Revision Date: 3/7/2012 Note: Oct 29, 2024 New link https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=915

Sigler, John W. and William F. Sigler. 1987. Fishes of the Great Basin: A Natural History. Reno, NV: University of NV Press. https://unpress.nevada.edu/9780874176940/fishes-of-the-great-basin/

Sloman, Katherine A., Rod W. Wilson, Sigal Balshine. 2006. Behaviour and Physiology of Fish. San Diego, CA: Elsevier Academic Press. https://shop.elsevier.com/books/fish-physiology-behaviour-and-physiology-of-fish/sloman/978-0-12-350448-7

Steward, Ron. 1994. Kokanee. Utah Division of Wildlife Resources. Wildlife Notebook Series No. 10. https://utah.ptfs.com/awweb/main.jsp?flag=collection&smd=1&cl=all_lib&lb_document_id=12657&itype=advs&menu=on
[accessed September 19, 2013] Downloaded and found at https://wildaboututah.org/wp-content/uploads/kokanee-dwr-booklet1.pdf

Ross, Crystal, Where to see Utah’s spawning kokanee salmon, Wildlife Blog, Utah Division of Wildlife Resources, August 29, 2019, https://wildlife.utah.gov/news/wildlife-blog/755-where-to-see-utah-s-spawning-kokanee-salmon.html [accessed October 29, 2024]