A Brief Coeur d'Alene Lake Fishtory

This story was written by Guest author: Erin Plue, Trout Unlimited on behalf of the Our Gem Collaborative team for the CDA Press on Sunday, December 18, 2022. Read the original article.

Did you know that some of the first train car occupants traveling from the eastern United States were baby fish? Early train cars were fitted with fish tanks, allowing people to bring their favorite familiar fish species with them to the waters of the West. This is just one of many factors that have changed the shape and inhabitants of Coeur d’Alene Lake since the 1800s. Operations of the Post Falls Dam have increased the amount of shallow, warm water lake habitat; human infrastructure and mining damages have made the two major tributaries to the lake less navigable for native trout species; and stocking (legal and illegal) have changed the face of the fishery by introducing non-native fish.

Coeur d’Alene Lake is long and thin with tributaries, bays and wetlands found around much of its 28-mile length. These features create an abundance of shallow waters, but the lake also reaches depths up to 192 feet. This diversity in waterscape creates a plethora of habitats which flourish with many fish species.

Before European influence, the Coeur d’Alene Lake fishery had robust populations of bull trout, Westslope cutthroat and whitefish. These native salmonids thrived in the abundant cold water and historically low nutrient systems of North Idaho for millennia. But with changes to the basin, that have occurred in the last 150 years, many of these migratory native fish, that depend on the lake to feed and grow, are struggling to survive. Notably, non-native fish are considered a primary reason that bull trout populations have declined to very low numbers in the Upper St. Joe River Basin. Most of the abundant populations of cutthroat and whitefish that people catch in the tributaries are fish that spend their entire lives in the river system and don’t migrate to the big lake.

…And just in case you were wondering, although Chinook, steelhead and coho salmon historically migrated up the Spokane River, they did not reach Coeur d’Alene Lake because they were geologically blocked by the natural rock dam at Spokane Falls.

Today’s Coeur d’Alene Lake fishery hosts lots of species of fish including declining populations of the native fish species and many introduced species. These more recently added species include, but are not limited to…

• Chinook salmon which are stocked, starting in 1982, and now naturally reproduce and spawn in the CDA system.
• Rainbow and brook trout can be found in the lake.
• Kokanee are a landlocked sockeye salmon and were stocked into CDA lake starting in 1937. Kokanee are now a self-sufficient, naturally reproducing population in the lake.
• Largemouth and smallmouth bass are prevalent and grow to large sizes in the nearshore waters of the southern lake.
• Northern pike are a favorite sport fish and a large predatory fish. They hide out in the plant growth in shallow areas, habitat that is common at the mouth of tributaries, where they ambush fish passing by.
• Perch, pumpkin seeds and crappie, shore-fishing favorites, also live in the lake.

As you can see, the lake ecosystem has seen abundant change in the last 100 years and changes are likely to continue. What the future Coeur d’Alene Lake fishery will look like remains to be seen.

The Our Gem Coeur d’Alene Lake Collaborative is a team of committed and passionate professionals working to preserve lake health and protect water quality by promoting community awareness of local water resources through education, outreach and stewardship. Our Gem includes local experts from the University of Idaho Community Water Resource Center, Coeur d’Alene Tribe, Idaho Department of Environmental Quality, Kootenai Environmental Alliance, Coeur d’Alene Regional Chamber of Commerce, and CDA 2030.