Biologists to talk about how Lake Spokane’s fish populations are changing

The fishery in Lake Spokane has been changing over the past few decades, and each change presents a trade-off.

Smallmouth bass are still thriving, and there are more trophy bronzebacks than there used to be. But that could be part of the reason largemouth bass are getting harder to find.

Meanwhile, the walleye population is booming, and there are anglers taking advantage. But those fish eat basically everything else in the lake, and they might be to blame for declines in other species.

Those are the trends Washington Department of Fish and Wildlife biologists have seen across three fish surveys from 2001 to 2024 in the lake between Long Lake Dam and the Nine Mile campground.

They will walk the public through the data at a public meeting on Thursday at Lakeside Middle School starting at 6 p.m. The data draw on extensive fish surveys done in 2001, 2015 and 2024, using electrofishing and gillnetting.

Danny Garrett, a WDFW warm water fish biologist, said the state put smallmouth bass in the lake in the 1990s at the request of local bass anglers. As a result, the lake became a fantastic smallmouth fishery, with abundant numbers.

Over time, the population has stayed strong, despite a slight decline in abundance showed by the 2024 survey. The 2024 survey also found more smallmouth in the 12- to 18-inch range.

That’s great news for anglers who like smallies, but Garrett said the fish can often outcompete largemouth bass, and that they might play a role in those fish becoming harder to find.

“They’re never going away, but there’s much fewer largemouth than there used to be in the 1990s and 2000s,” Garrett said.

Walleye present a different problem. The fish were almost certainly introduced illegally, since they are outside their range and there is little chance they found their way there naturally.

WDFW found its first walleye in the lake in 2001. The population remained at relatively low abundance for years, Garrett said. In the 2015 survey, they found a few walleye, but not enough to say the population was fully established.

That changed last year. The survey found the population had become fully established, with multiple age classes and walleye as old as 7.

Garrett said there were a lot of 2-year-old walleye, and that those fish were about 18 inches long.

“They’re really nice fish,” he said.

Of course, there’s a downside. Those 18-inch fish aren’t getting that way by eating salad.

Garrett said walleye eat whatever fish is available, and that they’re seeing declines in other fish species that could be attributed to the walleye.

Of particular concern are perch. Garrett said their gill nets found a lot of small perch last year, but that there were fewer perch in the 12 -inch range – the size anglers would like to batter and fry.

“A 12- or 10- or 14 -inch perch is a perfect meal for a 2-year -old walleye,” Garrett said.

Anglers have caught on to the walleye fishery. Garrett said his crews saw plenty of boats trolling for them last year while surveying.

He said that’s what WDFW wants to see – people taking advantage of the fishery that’s available.

And they want people to be aware of the problems illegal introductions produce.

“It’s also a cautionary tale to people who move fish around illegally,” Garrett said. “You’re not doing those other species any favors by putting a super predator in there.”