My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
7355
CWCB
>
UCREFRP
>
Public
>
7355
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
8/11/2009 11:32:56 AM
Creation date
8/10/2009 3:26:44 PM
Metadata
Fields
Template:
UCREFRP
UCREFRP Catalog Number
7355
Author
Wydoski, R. S.
Title
Assessment of Introduced Sport Fishes As Potential Competitors with or Predators upon the Rare Colorado River Fishes with Reference to Fishery Management in Kenney Reservoir.
USFW Year
1987.
USFW - Doc Type
Denver, Colorado.
Copyright Material
NO
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
20
PDF
Print
Pages to print
Enter page numbers and/or page ranges separated by commas. For example, 1,3,5-12.
After downloading, print the document using a PDF reader (e.g. Adobe Reader).
Show annotations
View images
View plain text
life stages of the rare fish. Various minnows have been introduced <br />intentionally as forage for sport fish or accidently from bait buckets into <br />the Upper Basin. Larger numbers of certain introduced fishes have been <br />correlated with lower numbers of some native fishes. For example, the red <br />shiner (Notropis lutrensis) is particularly abundant in the lower reaches of <br />the White River (Table 2, Green River (Table 3), and in certain habitats of <br />the Colorado River (Table 4). In these areas, the native species are not as <br />abundant. Management of sport fishes in the Upper Basin will require <br />management of forage organisms in a systematic way to minimize any potential <br />conflicts from competition. In fact, extra precautions may have to be taken <br />to ensure that recovery efforts are not hindered by stocking fishes that may <br />compete with or prey upon the rare fishes. <br />Moyle, Li, and Barton (1986) have summarized the detrimental impacts of fish <br />introductions on native species through competition and predation where the <br />native fish have become eliminated or nearly extirpated. More importantly, <br />they point out that introductions have altered fish communities throughout <br />North America and that numerous management problems have been created by the <br />resulting unstable fish communities. Magnuson (1976) summarized the problems <br />associated with animal introductions succinctly "as a game of chance". <br />Some management techniques to control nonnative species might include <br />regulation of streamflows. For example, Minckley and Meffe (1987) reported <br />that native fishes in the American southwest are favored by flooding in <br />streams. In another study, periodic, high flows in six unregulated Arizona <br />streams reduced the number of predatory sunfishes and catfishes while native <br />fishes were little affected (Meffe 1984). Streamflow manipulation will be <br />studied as part of the recovery implementation program for the rare Colorado <br />River fishes (U.S. Fish and Wildlife Service 1986). <br />The available information is sufficient to warrant caution in stocking these <br />warmwater predators or nonnative forage fishes in the Upper Colorado River <br />while recovery efforts for the rare Colorado River fishes are being <br />implemented. The studies outlined in the recovery implementation program <br />(U.S. Fish and Wildlife Service 1986) will provide information to be used in <br />making recommendations for recovery of the rare fishes. As knowledge is <br />acquired on the ecological requirements of the rare fishes and the <br />interactions of these fish with nonnative species, fishery management <br />practices can be adjusted when biologists are reasonably certain that the <br />outcomes will not have negative impacts on the rare fishes. <br />Although stocking of the rare Colorado River fishes will be a part of the <br />recovery effort (U.S. Fish and Wildlife Service 1986), recovery success to <br />develop naturally sustaining populations will depend on having available <br />suitable habitat to meet the ecological requirements of the rare fishes (Rinne <br />et al. 1986). Management practices will have to provide the best conditions <br />for survival of the rare fish, especially during the early years of life, <br />while reducing potential or actual competition and predation by nonnative <br />fishes. <br />Therefore, the FWS policy - "to oppose stocking of fish species that may <br />compete with or prey upon the rare fishes - will remain in effect until it <br />can be demonstrated that such introductions will have no significant impact on <br />the recovery of the rare fish. <br />10
The URL can be used to link to this page
Your browser does not support the video tag.