7108

• UCREFRP Catalog Number: 7108
• Author: Johnson, J. E.
• Title: Reintroducing the Natives
• USFW Year: 1985.
• USFW - Doc Type: Colorado Squawfish and Woundfin.
• Copyright Material: YES

121
Discussion
Decline of the Colorado squawfish in the tower basin of the Colorado
River has been well documented by Hinckley (1973). Once widespread in
in the lacer Colorado River basin (Fig. 1), little habitat remains for
this speries because of physical changes in habitats both above and
below mainstream impoundments. No spawning has been reported from
reservoirs or the cold, hypolimnetic waters below dams. Exotic fish
Species may also affect squawfish survival (IJSFWS 1978). squawfish were
last reported in the lower basin of the Colorado River in the early
197U's, at the base of Glen Canyon Dam. The last squawfish collected
from the Gila River in Arizona was by R.R. Miller and party in 19517
(?tiller 1961 ). In spite of repeated collecting of forts throughout
the period 1965-1985, in w11at appears to be suitable habitat in the
Salt, Verde and Gila rivers; no squawfish have been found. Colorado
sgnawfisi~ still. maintain SPawi-ng populations i.n the upper Colorado and
lower Crum rivers of Colorado and Illr~l,. '1'lae rcasnn~ fo:- the extc~rpatiun
of Colorado squawfish from the mainstream Gila, Salt and Verde rivers
above the uppermost dams is not known, although recent studies in the
upper Colorado River hasi n (Tyus, e_t at. 1981) indicate long distance
spawning) movements may he more important then was earlier he l.i.eved.
Woundfin w~>re once found throughout the lower reaches of the Cila River,
the ma instrea,n C~~lorado River at Yuma and likely upstream to the Virgin
River, and the 'Jirgin River and its tributaries upstream to LaVerkin
Spring; (Fig. 2)(Hinckley 1973). Since the turn of the century the species
has bean restricted to the Virgin River and a single tributary, LaVerkin
Creek (USF4JS 1985). Sven though the historic range of the woundf in in
the Gila River basin included only the m<;instream Gila River and the
Salt River below Tempe, the species was Probably also found in the upper
Gila and Salt rivers and their tributaries, the Agua Fria and llassayampa
rivers and perhaps even the San Pedro and Santa Cruz rivers. While
woundfin were never taken from these reaches, t11is can partially he
explained by a lack of early col lec_tions. '~o known barriers, including;
elevation, prevented the fish from reaching or occupying these localities.
it is believed that habitat in these streams was suitable for woundfin
and that at least periodically, the species was found there. These
habitats are included in the probable his [uric ranti;e of the woundf in.
Reintroduction of forts for Colorado squawfish and woundfin were
proposed in Arizona during 1976-1979 by the Ii, S. Fish and Wildlife Service.
No fish of either species was introduced durin;; [hat period because of
the apprehension of. several public and private agencies. These agencies
believed that once thP_ fish were re-established, the Endangered Species
Act (Act) would prevent ongoing and planned actions ~.ri thin the streams
as weL1 as the sur.ruunding watersheds (Johnson 198, 1985; Johnson and
Rinne 1982). At its meeting; in Las Cruces, Ni`l in 1978, the nesert Fishes
Council passed a resolution recommending; the addition of a new listing
catag;ary to the Act, cal led ex heri,~,ental', that .would eliminate manv of
the staunch protective regulations Eor reintroduced populations and
thus reduce opposition to those reintroducti.ons. That resolution was
supported by many agencies, and was eventually acted upon by Congress