Sometime around 2010, a ferocious beast appeared in Utah Lake.
Growing more than four feet in length, northern pike lurk near the bottom of the shallow lake’s murky waters, motionlessly waiting to dine on some hapless fish swimming past. Pike, with their mouthful of teeth, are revered as a sport fish for their fight, but the fast-growing predatory fish don’t belong in Utah Lake.
Anglers are to kill any pike they catch here, according to the Utah Division of Wildlife Resources, unless it bears a red plastic tag hanging from its body. In that case, the fish has been implanted with a transmitter as part of a telemetry study DWR is conducting to better understand this species’ population, feeding habits and movements.
Pike are just the latest in a string of nonnative organisms to invade the lake and upset its ecology. While valued by the angling community, pikes’ predatory habits threaten to unwind years of progress toward recovering June and Utah suckers, the last of the lake’s known 13 native fish species to still inhabit its waters.
“For that reason, we are asking anglers to assist us when they catch these fish, notifying us when they catch a tagged one,” said DWR biologist Keith Lawrence, a regional native aquatics program director. “That information will be extremely helpful toward our efforts to document their impact and control their spread.”
They also need to return tagged fish back to the lake alive.
While pike are unlikely to ever saturate the lake the way carp did, fisheries officials want to control their numbers before they seriously disrupt the lake’s already stressed ecosystem.
Every year, the catch rate for pike goes up, indicating their numbers in the lake are probably increasing, according to Dale Fonken, DWR’s leading June sucker biologist. That does not bode well for recovering native June and Utah sucker, the only native species that remain in the lake. Nonnative predatory fish are hard on suckers and other young fish and make for an easy meal.
“Walleye and bass, they eat a lot of fish, too, but pike are capable of eating larger fish than any other predator,” Fonken said. “We call it the gape limitation. Some predators are limited by the size of their mouth. Unfortunately, northern pike are much less gape-limited than other species.”
In the northern pike study’s completed first phase, biologists studied the stomach contents of pike brought in by anglers. These bellies yielded young June sucker, including adults as long as 16 inches, according to Fonken.
Other nonnatives fish in Utah Lake include perch, walleye, bass, bluegill channel catfish and black bullhead catfish.
The proliferation of northern pike in Utah Lake is a story playing out across the West where nonnative sport fish have been introduced, oftentimes illegally, into lakes and streams. In the absence of factors that would naturally keep their numbers in check, these can fish proliferate and displace cutthroat trout, suckers and other native fish.
Without some kind of control program, Utah Lake’s northern pike population is predicted to increase tenfold over the next 20 years, according to Lawrence.
This possibility prompted DWR to undertake the telemetry study in 2020. Since, biologists have captured 50 pike and surgically equipped them with transmitters and will track their movements around the lake for five years.
“We also have stationary sonic receivers out there that collect signals form fish that swim within a quarter mile,” Fonken said. “We have learned that these fish can move really far over a short period of time.”
The data the study generates will be help DWR keep their numbers in check.
Unchecked proliferation is what happened with Asian carp, which were deliberately introduced into Utah Lake in 1883 by well-intentioned people who hoped to boost pioneers’ food supply. Within a few decades, carp overwhelmed the lake, ravaged the lakebed and helped drive out native trout and push June sucker to the brink of extinction.
Today, the state spends hundreds of thousands of dollars netting carp and landfilling the carcasses, representing a huge waste of protein. Not even the cat-food and mink industries will buy these fish.
Unlike carp, people enjoy catching and eating pike, which are native to the Upper Midwest and have been planted all over the West. In Utah, they also inhabit Utah’s Yuba and Recapture reservoirs. Some have been observed in Lake Powell, where their numbers are believed to remain very low, according to Fonken.
The pike that got into Utah Lake were probably individuals illegally moved from Yuba Lake, he said.
So far, three tagged pike have been caught and released, including one in the Provo River.
For those interested in catching pike, try Lincoln Beach, Provo Bay and the mouth of Hobble Creek. That’s where the highest concentrations are found.
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