DWR to hold public meeting on proposal to treat Navajo Lake with rotenone

Dead fish after an application of rotenone in a body of water, date and location not specified. | Image courtesy of Utah Division of Wildlife Resources, St. George News / Cedar City News

SALT LAKE CITY — In an effort to restore the trout fishery at Navajo Lake and rid the waterbody of its overwhelming Utah chub population, the Utah Division of Wildlife Resources is considering a rotenone treatment later this fall. Before that fishery reset occurs, the DWR wants to meet with the public Sept. 10, explain the treatment process and answer questions about the proposed project.

Navajo Lake Trail, near Cedar City, Utah, date not specified | Photo by Jay Bartlett, St. George News / Cedar City News

According to a press release from the DWR, the proposed rotenone treatment for Navajo Lake, a popular fishing destination in Kane County, would tentatively occur mid-October.

Rotenone is a natural substance that comes from the roots of a tropical plant in the bean family. It’s a respiratory toxin to fish but isn’t dangerous to people, pets or other wildlife, especially in the extremely low quantities that biologists will use to treat the lake, the press release states.

DWR officials say Utah chubs have overrun Navajo Lake — making up over 90% of the fish in the waterbody — and currently outcompete the trout —rainbow, brook, splake and tiger trout — that are stocked there.

“Trout are the preferred species to fish for at this lake, which is why we are working to restore Navajo Lake as a prize trout fishery,” DWR Southern Region Aquatics Manager Richard Hepworth said in the press release.

“With the low water levels this year due to drought, this treatment to reset the fishery would be much more cost effective, so we thought it would be good timing. We have exhausted all our other tools and efforts to restore the fishery, so this is our last option.”

As originally reported by Cedar City News, Hepworth told the Iron County Commission in June that the treatment would likely occur sometime in September.

Rotenone treatments have proven to be an effective management tool when waterbodies are overrun by certain fish species. Hepworth told Cedar City News the last rotenone treatment of Navajo Lake took place in 1997.

Utah Chub, date and location not specified | Photo courtesy of the Utah Division of Wildlife Resources, St. George News

“So we got a little bit over 20 years out of that project,” he said, adding that he hopes this year’s treatment will last as long as 30 years, thanks to improved complement formulas and strategies.

In order to give anglers an opportunity to catch and keep additional fish from Navajo Lake prior to the proposed rotenone treatment, the DWR increased the daily fish limit to 16 trout (any size) on July 28.  That change is in effect until Oct. 31, 2021.

DWR biologists will be holding a public meeting to discuss the project and answer questions about this upcoming treatment. The informational meeting will be held Sept. 10 at 6 p.m. at the Duck Creek Village Fire Station, located at 3620 Mammoth Creek Road in Duck Creek Village. Those who can’t attend the meeting and want to provide feedback about the proposed treatment can email Hepworth at [email protected].

Copyright St. George News, SaintGeorgeUtah.com LLC, 2021, all rights reserved.

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