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INFO: Mammoth Creek closed for Bonneville Cutthroat Trout restoration

Posted at 1:09 PM, Sep 09, 2015
and last updated 2015-09-09 15:09:28-04

Information from Utah Division of Wildlife Resources:  

The Utah Division of Wildlife Resources will conduct a native Bonneville cutthroat trout restoration project using the piscicide rotenone within the Mammoth Creek drainage on the Dixie National Forest, beginning September 9, 2015.

The project is consistent with the conservation strategy for the species, which is designed to prevent the fish from being listed under the Endangered Species Act. The rotenone treatment is aimed to rid all species of fish in targeted streams, ponds, lakes and tributaries in order to restore the native Bonneville cutthroat trout to a portion of the Mammoth Creek drainage.

A temporary closure of these areas during the piscicide application will be necessary to allow ground crews to safely work in and around the lakes and streams without harm or injury to the public. All use of the water (wading, fishing, swimming, etc.) within the project area will be prohibited during piscicide application and neutralization.

Mammoth Creek is one of the primary tributaries of the Sevier River. In 2012, genetic testing confirmed that upper Mammoth Creek has a remnant population of native Bonneville cutthroat trout, the only known remnant population in the entire Upper Sevier River drainage. “Finding this native population is significant because despite the competition with the non-native fish, the Bonneville cutthroat have continued to survive,” said Angelita Bulletts, Forest Supervisor.

“Restoring Bonneville cutthroat trout in Mammoth Creek will help to improve the status of the species, the ecology of the stream and the quality of recreational fishing,” said Mike Golden, Dixie National Forest Fish Biologist.

The first phase of the project will begin in 2015 when two of Mammoth Creek’s tributaries, Castle Creek and Lowder Creek, will be chemically treated with rotenone to remove non-native brook trout. Treatment of Castle Creek is scheduled for September 9-September 11, 2015. The Lowder Creek treatment, which will include Lowder Pond, is scheduled for the week of September 21-25. Bonneville cutthroat trout will be transferred from Mammoth Creek to Lowder Creek and Castle Creek, following a second treatment of both streams in summer 2016.

The active ingredient in liquid rotenone is a powder derived from the roots of South American plant. Rotenone is specifically poisonous to gilled organisms because it interrupts oxygen uptake from the water at the cellular level. After the rotenone has been applied, potassium permanganate, an oxidizing agent, will be applied to treated waters below the target area to neutralize the rotenone in those areas. Although liquid rotenone (product names: Prenfish and CFT Legumine) is relatively benign to humans, fish treated with the chemical have not been cleared by the Food and Drug Administration for human consumption. For that reason, fish that die during the project cannot be salvaged.

The 2015 area closures are Pursuant to Title 36 Code of Federal Regulations 261.50 (a) and (b), the following areas will be closed during the treatments for protection of public health and safety:

  • Within 100 feet of Castle Creek and its tributaries from the confluence of Castle Creek with Mammoth Creek upstream through all Castle Creek drainage headwaters and the Deer Creek ditch conveyance (T36S, R8W, Sections 5, 6, 7, 8, 14, 15, 16, 17, 21 22, 23, 26 and 27, Salt Lake City Baseline and Meridian).
  • Within 100 feet of Lowder Creek (including Lowder Pond) and its tributaries from the confluence of Lowder Creek with Mammoth Creek upstream through all Lowder Creek drainage headwaters (T36S, R8W, Section 18, 19, 20, 28, 29, Salt Lake City Baseline and Meridian).

The temporary closure order is anticipated to be cancelled September 11, 2015 for Castle Creek and September 25, 2015 for the Lowder Creek project area.

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For more information on the Bonneville cutthroat trout restoration project please contact Lynn Chamberlain, DWR Southern Region Conservation Outreach Manager, 435-680-0059 or 435-613-6100 or Marcia Gilles, Dixie National Forest Public Affairs Officer, 435-865-3700.