Dam alterations allow June sucker to spawn farther upstream

PROVO — When the Fort Field Diversion dam was built on the lower Provo River in the early 1900s, it was designed to rechannel some of the water for irrigation.

But it also prevented the June sucker, a fish that lives only in Utah Lake, from swimming upstream to spawn and contributed to the decline of the fish population.

Now, wildlife officials are reporting that as many as 300 June suckers were seen moving upstream on the Provo River to spawn on a single night last month, after the century-old diversion dam was replaced to make it easier for the once-endangered fish to return to its traditional spawning grounds.

In the mid-1980s, when the June sucker was listed as an endangered species, the entire fish population was as low as 100 to 500.

"We were confident that we would see the fish spawning farther up the lake. The surprise is that it happened so fast," said Mike Mills, coordinator of the June Sucker Recovery Implementation Program.

The changes in the diversion, which were made in September, are part of an overall plan to help the June sucker recover. Mills said saving the June sucker may also be the key to saving Utah Lake.

"Today, the June Sucker Recovery Program provides us a mechanism to go out and make many improvements," Mills said. "And it appears to be helping."

Jackie Watson, a Utah Division of Wildlife Resources biologist, said she was impressed with the June sucker's rapid response to the diversion modifications.

"I have never seen June sucker this far upstream," Watson said. "We are thrilled to see this many June sucker spawn past the diversion. We thought it would take years before we would see fish this far up the river."

Mills said during the weeklong spawning, the fish were observed upstream of I-15.

"It was kind of an interesting year," he said. "They showed up late, the water cleared up, and within a week they were gone."

The recovery efforts are relying on an aggressive stocking program that has restored the lake's June sucker population to the tens of thousands.

"Right now, 90 percent of the June suckers in the lake were produced in a hatchery," Mills said. "We are planning on stocking another 30,000 June sucker this year. We'd like to change that by working on what we can. Eventually we'll get good habitat."

In addition to making changes in the diversion dam, the June Sucker Recovery Implementation Program, a cooperative effort of several state and federal agencies, has other programs under way, including an attempt to remove up to 5 million pounds of carp from the lake each year.

Carp, which were introduced into the lake by early settlers and have become the dominant fish species in the lake, are one of the main reasons for the June sucker's decline. Mills said the carp removal program is one of the things that will also help restore Utah Lake to its natural clear water state.

e-mail: mhaddock@desnews.com