My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
WSP08914
CWCB
>
Water Supply Protection
>
Backfile
>
8001-9000
>
WSP08914
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
1/26/2010 2:50:10 PM
Creation date
10/12/2006 3:21:16 AM
Metadata
Fields
Template:
Water Supply Protection
File Number
8240.200.10.C.5
Description
UCRBRIP
Basin
Colorado Mainstem
Date
1/1/1992
Author
USFWS
Title
Designating Critical Habitat Under the Endangered Species Act
Water Supply Pro - Doc Type
Publication
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
36
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
<br />sucker, bluehead sucker, razorback sucker, moapa White River sprlngfish, desert pupfish, monkey <br />spring pupfish, gila topminnow, striped mullet. <br /> <br />The Las Vegas Valley dace and the monkey spring pupfish are extinct. <br /> <br />5. Why are the fish considered .endangered" if they can easily be raised in hatcheries? <br /> <br />Hatchery-raised endangered fish are an Important part-but not all-of the solution. The purpose <br />ofthe Endangered Species Act Is to conserve, not only rare species of animals and plants, but also <br />the ecosystem on which they depend. Recovery goals call for "self-sustaining" populations of fish; <br />having to stock hatchery fish on an ongoing basis would not reach these goals or achieve the <br />purpose of the Endangered Species Act. Currently, the role of hatchery fish also Is limited for the <br />following reasons: <br /> <br />Some biologists believe that Colorado squawfish become .imprlnted" to a specific <br />spawning site at an early age and will spawn In that sIte only. Unless properly Imprinted, <br />hatchery-raised squawfish may not know where to go to spawn In the wild. <br /> <br />Existing' pop illations of hirtchli;y.ralsed 'eridangered'fish have been bred from a' very , <br />limited number of adult fish. The lack of variation In their .genetlc makeup" may reduce <br />their ability to survive In the wild. Also the stocked fish could harm wild fish populations <br />by competing with them for food or by Introducing new fish diseases and parasites. <br /> <br />In-stream flows must be maintained, and suitable habitat, such as protected backwaters <br />for young fish, must be available to support the fish's various stages of life. Without <br />Impr,ovlng the river habitat. it is unlikely that many of the fish that were stocked would <br />survive and successfully reproduce. <br /> <br />6. How will hatchery fish be used in recovery? <br /> <br />The use of hatchery-raised endangered fish Is an Important tool. Hatchery fish can be used In <br />studies that will aid the fishes' recovery. Hatchery facilities can be used to maintain captive or <br />"refuge" populations of wild fish to prevent such populations from going extinct In the event of an <br />011 spill or other nBlural disaster. To help establish self-sustaining populBllons, hatchery-raised <br />fish can be stocked In stretches of river where fish populations have severely dwindled or <br />disappeared. <br /> <br />Researchers are developing methods for "artificially imprinting" hatchery fish to spawning areas <br />,in the natural river environment. Also, biologists have captured small "brood stocks" of razorback <br />suckers and Colorado squawfish from the wild. These fish will be held In protective_ponds or <br />hatcheries for breeding. Biologists are working to improve techniques for raising endangered fish <br />in hatcheries. Other studies will determine whether fish from one river are genetically different <br />from those in another. Researchers hope that by applying the findings from these studies, they <br />will improve the chances for hatchery-raised endangered fish to survive and reproduce in the wild. <br /> <br />7. Why is there so much concern about Colorado squawfish when other squawfish are <br />abundant in California and the Northwest? <br /> <br />The answer Is simple: Just as the golden eagle and bald eagle are different species, the squawfish <br />found In California and the Northwest are distinct species from the Colorado squawfish. Each fish <br />species evolved In a different river system and now has different characteristics and different <br />responses to environmental changes. <br /> <br />None of the other species-the northern squawflsh (also called the Columbia River squawfish), <br />Sacramento squawfish and Umpqua squawflsh-has been known to grow to the size of the <br />Colorado squawflsh. which historically reached lengths of 6 feet. Also, the other species <br />populations are- doing well despite habitat alterations from the construction of dams and <br />Introductions of non-native fish species. The northern squawfish originally evolved in lakes and <br />appears to adapt easily to man-made reservoirs. In fact. unlike the Colorado squawflsh, the <br />northern squawflsh prey effectively on game fish and often become the dominant species in <br />reservoirs, despite biologists' efforts to limit their population size. <br />
The URL can be used to link to this page
Your browser does not support the video tag.