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<br />exotic species also provides that exotic species are managed within national parks so that they '
<br />will not spread or become pests on parks or adjacent lands: Exotic species are also managed so
<br />that available native species meet park management objectives. '
<br />Removal of exotic species already present is also an important aspect of Park Service
<br />management policies. All exotic plant and animals species that are not maintained to meet an '
<br />identified park purpose will be managed, including eradication if control is prudent and feasible,
<br />and the exotic species interferes with natural processes and perpetuation of natural features. The
<br />Park Service places low priority on exotic species that have almost no impact on park resources '
<br />or that probably cannot be successfully controlled.
<br />3.3 Pond Isolation and Rehabilitation '
<br />3.3.1 Colorado River Pond Reclamation (Project No. CAP-18/i9; Colorado Division of
<br />Wildlife ~CDOWJ) '
<br />An inventory of riverside ponds along the Colorado River between Rifle and Loma, Colorado,
<br />~
<br />and the Gunnison River between Austin, Colorado, and the confluence of the Colorado River '
<br />was conducted from 1997 through 2001. The objectives of the project were to:
<br />• negotiate access to private, public; and municipal ponds along the Colorado River
<br />downstream of Rifle and along the Gunnison River downstream of Austin;
<br />'
<br />• ensure cooperative lasting-working relationships with landowners;
<br />• remove unwanted nonnative fishes from riverside ponds via chemical treatment,
<br />water management, black plastic liners, or other techniques;
<br />'
<br />• install inlet/outlet screens to control movement of nonnative fish from riverside
<br />ponds into critical habitat; and
<br />
<br />• contribute to I&E efforts with interested PAI's when possible. '
<br />This inventory identified 744 ponds, similar to those reported by Mitchell (1995). Of these, 355 ,
<br />ponds were investigated, of which 198 supported fish, 39 were void offish, 21 were taken over
<br />by the river since the Mitchell (1995) report, 60 were ephemeral, and 17 were mistakenly
<br />identified as ponds by Mitchell (1995). A total of 237 private, public, and municipal ponds (total '
<br />of 737 surface acres) were sampled. A total of 15,316 fish (14,945 nonnative fish; 371 native
<br />fish) were collected in 198 ponds that supported fish (Figure 1). Nonnative non-sport, nonnative
<br />sport, and native fish comprised 84% (12,783), 14% (2,162), and 2% (371) of the total number of '
<br />fish sampled, respectively. Green sunfish (33%) was the most common fish species collected
<br />followed by fathead minnow (18%) and black bullhead (11%). Of the 24 fish species captured,
<br />totaling 15,316 fish, flannelmouth sucker, roundtail chub, and bluehead sucker comprised 1.3% '
<br />(193), 1.0% (146), and 0.2% (32) of the total number of fish, respectively. No threatened or
<br />endangered fish were collected.
<br />Treatments to control nonnative fish were applied to 75 ponds and included piscicides, water
<br />management, and black plastic pond liners. A total of 3,024,000 fish were chemically removed,
<br />including 500 native fish (<0.02%), 61,000 nonnative sport fish (2%), and 2,962,500 nonnative e
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