9554

• UCREFRP Catalog Number: 9554
• Author: Monroe, L. and T. Hedrick.
• Title: Northern Pike ‎(Esox lucius)‎ Control in the Middle Green River, Utah 2001-2006.
• USFW Year: 2008.
• USFW - Doc Type: 109,
• Copyright Material: NO

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Yampa River downstream into the middle Green River, into critical habitat for razorback sucker.

These fish moved down from between Yampa River Kilometer (RKM) 119.7 - 242.9 (River

Mile (RM) 74.4 - 150.9) for total movements between 192.1 and 306.5 river kilometers (119.4

and 190.5 river miles).

Capture rates of northern pike in the Green River in the late 1990's indicated a rapid

increase in the adult population: the number of northern pike captured during basin-wide

monitoring increased from 48 collected in 1997 to 202 in 1999. In addition, in 2002, U.S. Fish

and Wildlife Service crews observed numerous young-of-year (YOY) northern pike in Old

Charley Wash on the Ouray National Wildlife Refuge (Green River RKM 401.0 (RM 249.2)) (K.

Christopherson, pers. comm.) (Figure 1). This was dealt with through the use of Rotenone, a

piscicide; however, the possibility of an established northern pike population was still quite

alarming. Northern pike tend to prefer soft-rayed food fishes to pan fish or bullheads (Beyerle

and Williams 1968) and because of the potential predatory threat to native, endangered species,

the Program became very concerned and initiated a northern pike removal program in 2001. The

Program was also concerned that northern pike would pose a predatory threat to all native fishes,

including the non-endangered, "at risk" species such as roundtail chub (Gila robusta),

tlannelmouth sucker (Catostomus latipinnis) and bluehead sucker (Catostomus discobolus).

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