PHOENIX - The Arizona Game and Fish Department, the U.S. Forest Service, and the U.S. Fish and Wildlife Service have completed initial efforts to rid Fossil Creek, in north-central Arizona, of unwanted smallmouth bass. Non-native smallmouth bass had invaded Fossil Creek following floods during the winter of 2009/2010 that deposited rocks and boulders below a fish barrier and allowed bass to swim up and over it. Last week, field staff reported successfully removing some bass. A second treatment to remove any straggling bass is being conducted this week. Monitoring will follow.

In 2004, non-native species were removed from Fossil Creek to create a unique sanctuary for native aquatic species, including roundtail and headwater chub, which are two native sportfish species.

Last week, agency biologists used rotenone, a naturally occurring chemical piscicide, to remove smallmouth bass. The current treatment area of Fossil Creek is located between the Sally May Wash confluence (2 miles below the FS Road 708 crossing) and the repaired fish barrier in the Mazatzal Wilderness, approximately 2.6 miles downstream.

Fossil Creek, from just below Fossil Springs to the confluence with the Verde River has been temporarily closed to public access Sept. 10-28 to accommodate the renovation effort.

Rotenone affects gill-breathing species such as fish, has a short life span, and quickly biodegrades into harmless substances. As an additional precaution, potassium permanganate is applied below the treated area to expeditiously neutralize rotenone.  The neutralized water can temporarily take on a purple or pinkish-hue. Additional uses of potassium permanganate include treatment of canker sores (ulcers), and fungal infections of the hands or feet.  It is used extensively in the water treatment industry and by back-country hikers to disinfect drinking water.