Spring-Summer Movements of Bonytail in a
 

Colorado River Reservoir,
 

Lake Mohave, Arizona and Nevada
 

Open File Report 99-103 

BOlllyt3il (Gila elegans) 

U.S. Department of the Interior Prepared Jointly with Arizona State 

U.S. Geological Survey University. 
u.s. DEPARTMENT OF THE INTERIOR 

u.s. GEOLOGICAL SURVEY 

Spring-Summer Movements of Bonytail in a
 

Colorado River Reservoir,
 

Lake Mohave, Arizona and Nevada
 

By
 

lPaul C. Marsh, Arizona State University-Dept. Of Biology
 

and
 

2Gordon Mueller, U.S. Geological Survey-MESC
 

Open-File Report 99-1 03 

Prepared jointly with Arizona State University, Department of Biology. 

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey 

editorial standards (or with the North American Stratigraphic Code). Any use of trade, product, 

or firm names is for descriptive purposes only and does not imply endorsement by the U.S. 

Govenunent. 

IP.O. Box 871501, Tempe, .Arizona 85287 

2P.O. Box 25007, D-8220, Denver, Colorado 80225 
TABLE OF CONTENTS
 

EXECUTIVE SUMMARy 11 

INTRODUCTION 1 

METHODS 2 

RESULTS and DISCUSSION 6 

Patterns of Movement and Distribution 7 

Individual Tracking Histories 8 

Spatio-temporal Aspects ofFish Locations 11 

Fish Captures Associated with Tagged Bonytail 12 

CONCLUSIONS and RECOMMENDATIONS 13 

ACKl'JOWLEDGMENTS 14 

REFERENCES , 14 

APPENDIX A, 1996 Telemetry Tables and Figures 20 

APPENDIX B, 1997 Telemetry Tables and Figures 24 

TABLES 

Number 

1 Capture, implant, release and tag data for 5 pond-reared and 

5 wild-caught bonytail, Lake Mohave, Arizona-Nevada, 1996. 

Pond-reared fish were 1994-year class volunteer spawn Willow Beach 

National Fish Hatchery Arizona, and wild-caught fish were captured 

from the reservoir as indicated. .	 _. . . . . . . . . . . . .. 3
 

2	 Capture, implant, release and tag data for 3 pond-reared and 

7 wild-caught bonytail, Lake Mohave, Arizona-Nevada, 1997. 

Pond-reared fish were 1995-year class volunteer spa'WTI from 

Dexter National Fish Hatchery New Mexico reared at Cibola National 

Wildlife Refuge Arizona, and wild-caught fish were captured from 

the reservoir as indicated. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

3	 Contacts (number of observations) with cove-reared and Vvild-caught, 

sonic tagged bonytail in Lake Mohave, Arizona-Nevada, relative 

to time of day and proximity to shore, 14 May to 29 July 1996. . . . . . . . . . .. 12 

FIGURES 

Number 

Map of Lake Mohave, Arizona and Nevada, showing numbered 

waypoints 1-71 and reservoir zones l-S 5 
EXECUTIVE SUMMARY
 

The bonytail Gila elegans is a large-river miIlllow (Cyprinid) endemic to the Colorado River 

system of western North America. The species is federally listed as endangered, its biology 

poorly understood, and relatively little is known of its movements. Two short-term telemetry 

studies were conducted during 1996 and 1997 to assess spring-summer temporal and spatial 

movement patterns in Lake Mohave, Arizona and Nevada, where the largest remaining 

population of bonytail persists. A total of20 bonytail were implanted with 90-day sonic 

transmitters. Ten fish (5 wild-caught from the Lake and 5 cove-reared: 5 females and 5 males) 

were implanted in May 1996 and additional 10 (7 wild-caught and 3 pond-reared: 2 females and 

8 males) were implanted in April 1997, released into the lake immediately after surgery, and 

tracked approximately weekly through August of both years. 

Eight fish dispersed immediately after release in 1996, two moved up- and six moved down-lake. 

The five wild-caught fish moved down-lake as much as 42 kID, and four of these (all males) 

remained in the lower most 5 kID while the other (female) occupied an area about 10 krn below 

the release site. Two cove fish moved up lake 15 and 43 krn, respectively, while a third moved 

4 kID down-lake. Two fish were never contacted. Most locations were in shallow water along 

shorelines, in some instance within inundated stands of riparian vegetation. 

In 1997, three pond fish were surgically implanted with transmitters and released at Cottonwood 

Cove, Nevada. Two were not contacted again, and the other was lost 12 days post-release after 

moving approximately 1.4 krn across the lake. Seven wild fish were captured and released at two 

sites in the lower portion of the lake, and all moved to downstream areas where they remained 

for the duration of study. Contact was lost with one fish after 3 days and another remained 

stationary after 13 days; the five others were tracked for 62 to 119 days. These last fish remained 

in the lower lake and had net movement (displacement from release site to last contact location) 

that averaged 5.4 kID and ranged from 4.7 to 6.9 kID. All net displacements were downstream. 

Cumulative distance traveled averaged 28.9 krn and ranged from 19.9 to 33.0 krn. Most fish 

locations during daylight hours were in deep water adjacent to the steep Nevada shore, while 

nighttime locations were in shallow water along gently ,sloping Arizona shorelines. 

Bonytail can move substantial distances in a short time (lOs of kID in a few days). Fish in both 

years apparently favored the same areas, where they may remain for weeks. Unmarked bonytail 

were observed or captured by setting nets in places favored by tagged fish, a significant result 

since future use ofthe technique may enhance our ability to monitor reintroductions, locate and 

document spawning, examine habitat use, and acquire desperately needed brood stock for this 

critically imperiled species. External tagging techniques developed forjuvenile razorback sucker 

may provide a method ofminimizing telemetry induced stress while allowing us to focus 

sampling on congregation sites. 

J] 
INTRODUCTION
 

The native "big-river" fish fauna of the western North America's Colorado River is comprised of
 

three endemic mirulOws (Cyprinidae): bonytail (Gila elegans), humpback chub (Gila cypha), and
 

Colorado pikeminnow (Ptychocheilus lucius), and one endemic sucker (Catostomidae):
 

razorback sucker (Xyrauchen texanus). In the lower Colorado River basin (below Lees Ferry,
 

Arizona), humpback chub historically was found primarily above Black Canyon (present site of
 

Hoover [Boulder] Dam, while the other three species were widespread in the Colorado River
 

mainstream and its major tributaries including the Gila., Salt, and Verde rivers (Minckley 1973,
 

Holden 1980a, b; Holden and Minckley 1980).
 

Water development in the lower Colorado River basin during the past century has involved
 

construction of dams and diversions, creation ofimpoundments, and channelization that has
 

modified aquatic habitats and altered natural hydrography (Fradkin 1968, Minckley 1979,
 

Worster 1985). Coincident with this development was the intentional or accidental introduction
 

of a suite of non-native fishes (U.S. Fish and Wildlife Service [USFWS] 1980). These structural,
 

hydrologic, and biological changes were coincident with and continue to be associated with
 

declines in native fishes of the region (Dill 1944, Miller 1961, Minckley 1973, Minckley and
 

Deacon 1991). In Arizona., for example, more than half the 30 native fish species are now
 

federally listed as threatened or endangered (Johnson 1987); the four "big-river" fishes all fall
 

into the latter category.
 

Most native species that historically occupied springs, smaller streams, and cienegas still persist
 

in isolated "strongholds" where habitats maintain a semblance oftheir natural states and are
 

relatively free of non-native fishes (Minck1ey 1985). This is not the case for the "big-river"
 

forms, which now are restricted to only a few places, all of which are occupied by an abundance
 

of alien kinds (Miller et a1. 1982, USFWS 1982). The big rivers of the region, without
 

exception, have been modified by the activities oftechnologic man.
 

Bonytail remains only in lakes Mohave (Arizona and Nevada) and Havasu (Arizona and
 

California), and is reliably captured only in the former locale (Marsh and Minck1ey 1992).
 

Humpback chub is restricted to the Colorado and Little Colorado Rivers in Grand Canyon, where
 

a relatively large population persists (Minckley 1991). It also is found in several canyon-bound
 

segments of the Green, Colorado, and Yampa Rivers in the upper Colorado River basin (Tyus
 

and Karp 1989). Colorado pikemiIll10w is extirpated from the lower basin (Minckley 1973), and
 

persists upstream only in portions ofthe Colorado-Green River system (Tyus 1991). Razorback
 

sucker is extirpated from the Gila River system (Minckley 1983), and is widely scattered
 

elsewhere in the upper and lower basins (McAda and Wydoski 1980, Marsh and Minckley
 

1989); the largest remaining population inhabits Lake Mohave (Marsh 1994).
 

Remnant populations of big-river fishes all appear to suffer from recruitment problems. Bonytail
 

and razorback sucker are not known (few exceptions with razorback sucker) to recruit to
 
reproductive size/age anywhere in the wild (Mueller and Marsh 1995), humpback chub does so 

only within a few river reaches in and upstream of Grand Canyon (Minckley 1991), and 

Colorado pikeminnow recruitment apparently occurs only within limited stream reaches of the 

upper Green River basin (Tyus 1991). 

Although a suite of factors are cited as responsible for declines and local/regional extirpations of 

the big river fishes (e.g., Miller 1961, Minckley and Deacon 1991), direct and indirect impacts 

associated with construction and operation of main stem dams and interaction with non-native 

fishes are considered most significant (Marsh, in press a and b; Mueller and Marsh 1995). 

The present study was developed to provide information on dispersal, distribution, and habitat 

use of bonytail in Lake Mohave. In part, the effort was to replicate and hopefully corroborate 

findings of a similar study performed in 1996 (Marsh 1997b). Both endeavors were to enhance 

our understanding ofthe life history of wild bonytail in the reservoir, and to provide management 

insights that might be useful in implementing and assessing an ongoing repatriation program. 

METHODS 

Ten adult bonytail were implanted with sonic transmitters in both May 1996 and April 1997 

(Tables 1 & 2). Both wild-caught and pond-reared fish were used. Seven were produced in 

hatchery ponds and reared in captivity, and 13 were wild-caught, or resident fish from Lake 

Mohave. The pond fish were 1994-95 year-class spawn ofFl adults (Lake Mohave stock) at 

Dexter, New Mexico and came from either Willow Beach National Fish Hatchery or from ponds 

at Cibola National Wildfire Refuge, Arizona. Pond-reared fish used in 1996 included 4 females 

that were 35.5 to 42.7 em total length (TL) and a male 36.3 em long. All pond-reated fish (3) 

used in 1997 were male, and they were 35.4,39.0 and 42.0 em TL. 

Lake fish were either wild or repatriated individuals captured in trammel nets set in vicinity of 

Arrowhead, Bill Gayes, Dandy, and Yoke Coves. Four males (43.0-46.5 cm~) and one female 

(46.1 em TL) were used in 1996 compared to two females (46.9 and 47.5 cm TL), and five males 

(46.8 to 48.8 em TL) used in 1997. Size ofimplanted pond fish was substantially smaller, 

however, lake fish were similar in size to wild-caught individuals captured from the reservoir 

between 1980 and 1996 (Tables 1 & 2; Marsh 1996, 1997a). 

Cylindrical sonic tags (Sonotronics Inc, Tucson Arizona part number MT-95-2) measured 

approximately 32 mm long x 8-mm diameter, were encased in inert ABS plastic, and weighed 

5 gm. These were surgically implanted into fish anaesthetized with 125 mg/L MS-222 (tricane 

methane sulfonate), through a 12-15 mrn-long medial incision through the abdominal 

musculature into the peritoneal cavity a few mrn off the ventral midline just anterior to the pelvic 

girdle. Anesthesia was maintained by continuous irrigation of the gills, and a damp towel to 

prevent drying covered the body. A Passive Integrated Transponder (PIT) tag (codes in Tables 1 

& 2) was inserted with each sonic tag, and the incision was closed with 2-3 sutures of 2-0 metric 

2 
(Dermalon) monofilament nylon. Time from initial immersion in anesthesia to removal to fresh 

water never exceeded 8 minutes, and fish were released after 2-5 minutes recovery in fresh water. 

Table 1. Capture, implant, release and tag data for 5 pond-reared and 5 wild-caught bonytail, 

Lake Mohave, ,Arizona-Nevada, 1996, Pond-reared fish were 1994-year class volunteer spawn 

from Dexter, New Mexico and supplied by Willow Beach National Fish Hatchery, Arizona., and 

wild-caught fish were captured from the reservoir as indicated. 

Capture Capture Implant Release TL Tag Code PIT tag 

Date Location Date Location (em) Sex Frequency Number Comment 

----------_..----------------_..._-*'--------------------------------_...._-------------------...-----------------------------------_..----_..-----­

POND REARED FISH 

14 May North Ala 14 May 1st N Carpb 36.3 M 2-3(74) 7F7D223042 ASU trammel 

14 May North Ala 14 May 1st N Carp" 39,6 F 3-4(74) 7F7DlB7315 ASU trammel 

14 May North Ala 14 May 1st N Carp" 42.7 F 5-5(74) 7F7D18437E ASU trammel 

15 May North Ala 15 May North Al 42.2 F 4-4(72) One of3 ASU trammel 

23 May WBNFW 23 May 1st N 116d 35.5 F 2-2(74) 7F7D132B70 Hatchery 

WILD CAUGHT FISH 

15 May Bill Gayes IS May Acr CWC' 46.2 M 2-6(72) 2024607666 ASU/FWS 

16 May Bill Gayes 16 May Levi Cove 46.1 F 3-3 (74) None ASUiFWS 

14 May Arrowhead 16 May 1stN116 43.0 M 2-5 (72) 7F7F32170F AZGFD 

14 May Arrowhead 16 May 1st N 116 45.5 M 3-5 (72) 7F7F317603 AZGFD 

14 May Dandy 16 May IstN 116 46.5 M 2-4 (74) 7F7F320E2A USBR 

aNorth Arizona luvenile backwater Arizona 

" First small cove north of Carp Cove Arizona 

" US Fish and Wildlife Service Willow Beach National Fish Hatchery Arizona 

d First cove north of Copper Basin Cove Nevada (US National Park Service number 116) 

•On the Arizona side directly across the reservoir from Cottonwood Cove Nevada 

3 
Table 2. Capture, implant, release and tag data for 3 pond-reared and 7 wild-caught bonytail, 

Lake Mohave, Arizona-Nevada, 1997. Pond-reared fish were 1995-year class volunteer spa\Vl1 

from Dexter, New Mexico reared in ponds at Cibola National Wildlife Refuge, Arizona, and 

wild-caught fish were captured from the reservoir as indicated. 

Capture Capture Implant Release TL Tag code PIT tag 

date location date location (em) Sex frequency number Comment ... _ .._____________w _____________... _____________... __________.._____________... __.. __________________... _______________________________________________ 

POND REARED FISH 

01 Apr Cibola' 02 Apr CWCNyb 35.4 M 3-4 (70) 2038596966 ASU/FWS trammel 

01 Apr Cibola 02 Apr CWC 42.0 M 3-6 (70) 7F7A062475 ASU/FWS trammel 

01 Apr Cibola 02 Apr CWC 40.6 M 3-5 (70) 7F7A08123E ASU/FWS trammel 

WILD CAUGHT FISH 

15 Apr Yoke Cove ]5 Apr S Pt KPCc 47.5 F 2-3 (70) IF77734F28 ASUiBRD trammel 

15 Apr Yoke Cove 15 Apr S Pt KPC 46.8 M 2-4 (70) 20lD616200 ASUlBRD trammel 

]5 Apr Yoke Cove 15 Apr S Pt KPC 47.0 M 3-3 (70) 7F7A08272A ASUIBRD trammel 

IS Apr Yoke Cove 15 Apr S Pt KPC 48.8 M 4-6 (70) IF78375I61 ASUIBRD trammel 

16 Apr Yoke Cove 16 Apr Beaver Cvd 48.8 M 4-5 (70) 2038587E52 AS1JIBRD trammel 

18 Apr Yoke Cove 18 Apr S Bas Lt Cve 48.5 M 4-4 (70) 2037107029 ASUIBRD trammel 

]8 Apr Yoke Cove 18 Apr S Bas Lt Cv 46.9 F 5-6 (70) IF7A346E45 ASUIBRD trammel 

a US Fish and Wildlife Service Cibola National Wildlife Refuge, Arizona 

b Cottonwood Cove Resort & Marina Beach, Nevada (US National Park Service [NPS] cove number 107) 

, South Point of Katherine Powerline Cove, Arizona (NPS no. 39) 

d Beaver Cove, Arizona (NPS no. 20) 

e South Basin Light Cove, Arizona (NPS no. 77) 

Tracking was performed using an USR-5W receiver and DH-2 hydrophone (Sonotronics, Inc, 

Tucson, Arizona), with signals amplified and audibilized through a dual speaker headset. Tags 

were programmed to operate at a frequency in the 70 kHz range and modified by extending pulse 

interval to 1.7 sec to extend nominal life expectancy from 47-90 days. Sonic signal detection 

range depends on tag power, obstructions and other underwater structure, turbulence, wave 

action, watercraft activity, power generation status (when near dams), and other factors, and 

during this study typically was> 500 m and approached 1000 m under ideal listening conditions. 

Nominal, routine monitoring consisted of stops at each of71 listening stations or "waypoints" 

(WP) designated at approximately 1.6-km intervals and forming a grid that provided 

approximately 85% surface area coverage of the reservoir (Fig. 1). In practice, most listening 

was done at lh WP or shorter (0.5-0.8 km) intervals. Location and repetitive relocation of each 

4 
21 

lluu\ 1:, DIlI'II 

INn) IXJl,lI I 

!d{lC I ;\l",I",':\\j!! ( I~;,\tdl' ------ -_._--- - .... ---_.. 

- Zone 4 [nleIface Zone f)U\ I~ I )<)!!, 

MAP OF LAKE MOHA VE 

- Zone 2- Cottonwood BaslO - lone :) J31<l(~ Cam un 30 

N 

t 

o 5Km I ---l 

Figure "1 M;:-Jp of L3kc MOf'13ve Arizona and Nevac1a, showing numbered waypoints 1-71 and reservoir zones 1-5 
WP was accomplished by use of a Magellan NAV 5000 DX Geographical Positioning System 

(GPS) instrument. Once a signal was detected, the fish location was determined by triangulation, 

identified by GPS output, and recorded as degrees, minutes and seconds oflatitude and longitude 

(later translated into DTMs for graphical interpretation). A visual estimate was made of distance 

to shore, and anecdotal notes also were recorded. 

The reseDioir was examined in entirety (all 71 WPs) at least once every 2 weeks from fish release 

(Appendixes A & B, Table 1) until tag expiration. In addition, several complete or partial "cove 

surveys" were conducted that examined all or a portion of the lakes coves and shorelines. These 

latter surveys were performed in an attempt to locate fish/tags in places from which signals might 

not propagate well, such as the backs of long coves. 

The reservoir was sub-divided into 5 zones or areas, each characterized by similar limnological 

and morphological features (Figure 1). Designated areas were Black Canyon (Hoover Dam to 

WP 13), Interface (WP 13 to 24), Castle Cliff Basin (24 to 40), Cottonwood Basin (40 to 61), 

and ReseDioir Canyon (WP 61 to Davis Dam). These correspond with zones used by Foster et 

al. (1997), Knowles (1997) and Marsh (1997b), but not by Marsh (l997c). 

Fish movement was assessed quantitatively on the basis of point-to-point distance (the linear 

distance in Ian between successive contacts), net distance (the total linear distance between point 

of release and each successive contact), and cumulative distance (the sum of all point-to-point 

distances). We plotted each contact location on a map of Lake Mohave and examined direction 

of movement (up- or down-lake) and movement between reservoir zones. 

Lake Mohave surface elevation varied slightly less than 2 m (6+ ft) from 194.65 to 196.52 m 

(638.63 to 644.75 ft) MSL, daily discharge from Hoover Dam averaged 471 and 500 CMS 

(16,633-17,675 CFS) (range 189 to 736 CMS [6,670 to 26,000 CFS]), and daily release from 

Davis Dam averaged 462 and 498 CMS (16,313 CFS) (range 270 to 603 CMS [9,520 to 21,300 

CFS]) during the study period between April and September 1996 and 1997 (U.S. Bureau of 

Reclamation, unpublished data). 

RESULTS and DISCUSSION 

All fish survived the anesthesia and surgery, and swam vigorously away when released into the 

lake. All releases were in quiet, protected coves. Nine fish were released in 1995 between WP 

36 and 40 in the lower portion of Castle Cliff Basin and one was released in Cottonwood Basin, 

at ,L\rizona Juvenile backwater, Arizona. In 1997 three pond-reared fish were released from the 

campground beach at the back of Cottonwood Cove, Nevada, in Castle Cliff Basin immediately 

upstream from the Cottonwood Basin transition, and the seven wild-caught fish were released 

between Beaver and South Basin Light Coves, Arizona in the Reservoir Canyon portion ofthe 

lake. Tracking was conducted from the first releases (14 May-1996/ 02 April-1997) for 

6 
approximately 4 months (August 1996-September 1997), after which time batteries presumably 

expired (no contacts were made during the last comprehensive, reservoir wide survey). 

Individual fish were contacted once (at time of release) to two dozen times over monitoring 

period (Appendix A & B: Table 1A-J, Figures 2-11). 

Patterns of Movement and Distribution 

1996 - Generally, wild-caught fish moved dovmstream into the lowermost portion of the 

Reservoir Canyons zone (Appendix A, Table 3A-E and Figures 1-6), and, if a pattern existed, 

cove-reared fIsh moved upstream (Appendix A, Table 3F-J and Figures 7-11). 

Four of five wild-caught fish moved down-lake about 56 km from release locations near \V1'-35­

38 to positions in the lowermost portion ofthe reservoir between WP 67 and 71. This movement 

was accomplished in the first 4 to 14 days after release, and all fish remained in the lower reaches 

of the Reservoir Canyon area until contact was lost up to 10 weeks later. This reach is 

characterized by a relatively narrow channel (1 OOs of m), steep, rocky shorelines with extensive 

development, and the deepest water anywhere in the lake (to near 40 m during the survey 

period). Summertime water surface temperatures in this portion ofthe reservoir exceeded 25 c C 

and may approach 30°C, while those below 10 m depth may remain near 15°C (Paulson et al. 

1980). 

There were no other evident patterns. The other wild-caught fish moved down-lake about 14 km 

immediately after release and remained mostly near-shore within a few km of WP 54 for the next 

5-plus weeks until contact was lost. Among cove-reared fish, one moved dowll-lake 

approximately 14 km and the other two moved up-lake 16 and 48 em, respectively. At no time 

were the latter two fish found in proximity to one another; for example, they were separated by 

more than 11 kID when both were contacted on 21 May. 

There was no post-release contact with two fish; both cove-reared. Explanations include 

immediate failure of the tag, or removal ofthe fish from the system (for example, by avian 

predators or scavengers such as bald eagles, ospreys or ravens, or by coyotes). There is no 

information to support or refute either alternative. 

1997 - Generally, wild-caught fish with which contact was maintained moved downstream from 

their respective release sites into the lowermost portion ofthe Reservoir Canyon zone (Appendix 

B, Table 2D-H and Figures 6-10). This pattern of movement and distribution was consistent for 

both years. This gross movement in both years was accomplished in the first 4 to 14 days after 

release, and all fish remained in the lower reaches of the Reservoir Canyon area until contact was 

lost up to 17 weeks later). 

Most contacts were made during evening hours and little information on diel changes in 

7 
distribution is available from this study. However, contacts made during daylight were generally 

with fish in deep water associated with the steep Nevada shoreline, while during evening fish 

were found in a variety of habitats and depths, often in shallow water along the Arizona 

shoreline. Similar results were reported by Marsh (1997b) for bonytail tracked during 1996. 

Two or more tagged bonytail were contacted in close proximity on several occasions, and visual 

contact was made during one such encounter. Previous speculation that tagged fish might lead 

researchers to other, unmarked bonytail was confirmed in 1996 (see Marsh 1997b), and similar 

efforts were expended during spring-summer 1997 as part of this study. Indeed, wild-caught 

bonytail used here were obtained primarily from the same sites occupied by fish that were tagged 

and tracked during 1996. Only non-native species were otherwise captured in net sets made 

during 1997, however, effort was limited to relatively few nets deployed on only a few dates. 

The capture of unmarked bonytail adults in an area used by marked fish remains a significant 

result because it suggests a potential mechanism to enhance sampling efforts in behalf of brood 

fish acquisition. 

Individual Tracking Histories 

1996 - Refer generally to Appendix A, Figure 1 for WP locations, and to Appendix A, Table IAJ, and Appendix A, Figures 2-11 for data on each fish. Individuals are identified by their source 

(i.e., \vild-caught or cove-reared) and sonic tag code number. 

Wild 2-4. Released 16 May 1996 at the first cove north of Copper Mountain Cove, Nevada in 

the lower portion of Castle Cliff Basin. Contacted upstream <1 kIn near WP 35 on day 8, then 

downstream 31.5 kIn at WP 67.5 in the lower Reservoir Canyons on day 15. Fish remained there 

(contact between WP 68 and 70.3 on 12 occasions from day 19 to day 75. Last contact was on 

29 July. YIaximum linear displacement downstream from point of release was 35.3 kIn, and total 

cumulative point to point distance moved was 42.7 km. 

Wild 2-5. Released 16 May 1997 at the first cove north of Copper Mountain Cove, Nevada in 

the lower portion of Castle Cliff Basin. Next contacted 31.3 kIn downstream near \VP 68 in the 

lower Reservoir Canyons on day 15. Fish remained in vicinity at \VP 67-69.3 on days 19-21, 28 

and 33. Last contact was 17 June. Maximum linear displacement downstream from point of 

release was 32.9 km, and total cumulative point-to-point distance moved was 36.4 kIn. 

Wild 2-6. Released 16 May 1996 on the Arizona side directly across the lake from Cottonwood 

Cove Marina in the Lower portion of Castle Cliff Basin. Contacted 32.6 km downstream near 

\VP 71 on day 5, then 2.1 kIn further downstream days 6 and 8 at WP 70 in the lower Reservoir 

Canyons. Fish remained there (contacted at WP 70.5 on day 16). Last contact was on 30 May. 

Maximum linear displacement downstream from point of release was 32.6 kIn, and total 

cumulative point-to-point distance moved was 34.6 km. 

8 
Wild 3-3. Released 16 May 1996 at Levi Cove, Arizona upstream from WP 39 in the lower 

portion of Castle Cliff Basin. Contacted 7.8 kIn downstream near WP 53 on day 4, on the 

Nevada shoreline oflower Cottonwood Basin. The fish remained in the vicinity ofWP 52-54, 

where it was recontacted 8 times between days 5 and 43. Lake contact was on 27 June. 

Maximum linear displacement downstream from point of release was 9.9 kIn, and total 

cumulative point-to-point distance moved was 18.1 kIn. 

Wild 3-5. Released 16 May 1996 at the flrst cove north of Copper Mountain Cove, Nevada in 

the lower portion of Castle Cliff Basin. Next contacted 2.4 kIn upstream near WP 34 on day 3. 

Fish moved 24 km downstream and was contacted near WP 62 in the lower Reservoir Canyons 

on day 5, and 10.3 kIn further downlake near WP 68 on day 7 where it was recontacted on day 

15. Last contact was on 30 May. Maximum linear displacement downstream from point of 

release was 31.9 kIn, and total cumulative point-to-point distance moved was 36.7 kIn. 

Wild 5-5. Released 14 May 1996 from the first cove north of Carp Cove AZ (due E ofWP 40), 

in the lower portion of Castle Cliff Basin. Contact 15.3 kIn upstream at WP 29 on Day 8, and 

11.5 kIn back down the lake at WP 36 on day 10. Last contact was on 23 May. Maximum linear 

upstream displacement from point of release was 15.3 kIn, and total cumulative point-to-point 

distance moved was 26.8 km. 

Cove 2-2. Released 23 May 1996 from the first cove north of Copper Mountain Cove, Nevada in 

the lower portion of Castle Cliff Basin. No post-release contact. 

Cove 2-3. Released 14 May 1996 from the first cove north of Carp Cove, Arizona (due E of 

WP 40), in the lower portion of Castle Cliff Basin. Contacted upstream at WP 36 on day 8, 17.5 

(day 36),19.3 (day 37), 9.3 (day 46), and there after at WP 17 (days 57, 64, and 72). The tag 

malfunctioned by 16 July and last contact was on 24 July. Maximum linear upstream 

displacement from point of release was 55 kIn, and total cumulative point-to-point distance 

moved was 75 cm. 

Cove 3-4. Released 14 May 1996 from the first cove north of Carp Cove, Arizona (due E of WP 

40), in the lower portion of Castle Cliff Basin. No post-release contact. 

Cove 4-4. Released 15 May 1996 at "North Arizona Juvenile" backwater (on the Arizona shore 

E of WP 50) in the lower portion of Cottonwood Basin. Contacted across the lake and 4 km 

dovmstream near WP 59 on day 29. Last contact was on 12 June. Maximum linear upstream 

displacement from point of release was 4 km, and total cumulative point-to-point distance moved 

was 26.8 km. 

1997 - Refer generally to Figure 1 for WP locations and reservoir zones, and to Appendix B, 

Tables 1A-J, and Figures 2-11 for data on individual fish. Individuals are identifIed by their 

9 
source (i.e., wild-caught or cove-reared) and two-digit sonic tag code number. 

Pond-reared 3-4. Released 02 April 1997 at the campground beach at Cottonwood Cove Resort 

and Marina, Nevada, in the lowermost portion of Castle Cliff Basin. Contacted twice on day 12: 

first in mid-channel ca. 1 lan from the release site, and later near the Arizona shore adjacent to 

WP 38.75 at Airport Cove. Last contact was on 13 April. Maximum linear displacement from 

point of release was 1.60 lan, and total cumulative point to point distance moved was 2.02 lan. 

Either the tag failed or this fish died and was removed from the system after April 13. There 

were no obvious indications ofmortality factors during the surgical procedure or at time of 

release. 

Pond-reared 3-5. Released 02 April 1997 at 1997 at the campground beach at Cottonwood Cove 

Resort and Marina, Nevada, in the lowermost portion of Castle Cliff Basin. There was no postrelease contact with this fish. Either the tag failed or this fish died and was removed from the 

system after April 2. There were no obvious indications of mortality factors during the surgical 

procedure or at time of release. 

Pond-reared 3-6. Released 02 April 1997 at the campground beach at Cottonwood Cove Reson 

and Marina, Nevada, in the lowermost portion of Castle Cliff Basin. There was no post-release 

contact with this fish. 

Wild-caught 2-3. Released 15 April 1997 at Katherine Powerline Cove, Arizona adjacent to WP 

66.6 in the Reservoir Canyon portion of the lake. Contacted about 4.8 lan downstream near WP 

69.5 on day 7, along the Arizona shoreline. The fish remained in vicinity ofWPs 66-71 in the 

Reservoir Canyon, where it was re-contacted on 17 occasions between days 17 and 80. This fish 

was detected in deep water along the Nevada cliffs, in open water of mid-channel, and in shallow 

water near the .Arizona shore. It was visually contacted on day 28 on the south point of Yoke 

Cove, Arizona (near \VP 68.1), where it was accompanied by wild-caught 3-3 (see below). On 

day 37, this fish and wild-caught 4-5 were detected in close proximity to each other near 

WP 70.4. Last contact was on 03 July. Maximum linear displacement from point of release was 

6.78 lan dov-mstream, and total cumulative point to point distance moved was 32.35 lan. 

Wild-caught 2-4. Released 15 April 1997 at Katherine Powerline Cove, Arizona adjacent to \VP 

66.6 in the Reservoir Canyon portion of the lake. Next contacted 5.7 kIn downstream in midchannel near \VP 70 on day 17. Fish moved only locally thereafter, and was contacted on 11 

occasions between days 17 and 98 near \VPs 67-71 in the lower Reservoir Canyon. It was 

detected along with wild-caught 3-3 in shallow water near \VP 68 on day 23, and with 3-3 and 4­

4 inside Telephone Cove, Arizona on day 98. This fish occupied a variety of depths and habitats 

over the 3+ months of contact. Last contact was on 21 July (day 98). Maximum linear 

displacement downstream from point of release was downstream 8.35 lan, and total cumulative 

point-to-point distance moved was 31.32 lan. 

10 
Wild-caught 3-3. Released 15 April 1997 at Katherine Powerline Cove, Arizona adjacent to 

WP 66.6 in the Reservoir Canyon portion ofthe lake.. This fish was first contacted on day 7 

about 5.6 krn downstream from the release site about 50 m off the Nevada shore adjacent to sheer 

cliffs near VIP 70. Most movements thereafter were ofrelatively shore distance. The fish was 

re-contacted on 19 subsequent occasions between VIPs 68 and 71, almost always in association 

with the Arizona shoreline. It was detected on day 28 along with wild-caught 2-4 in shallow 

water along the south point of Arrowhead Cove, Arizona, with 4-4 in 10-12 m depth in 

Telephone Cove, Arizona on day 91, with 2-4 and 4-4 in the same area on day 98, and again with 

4-4 near shore along the north point of Telephone Cove, Arizona on day 119. Last contact was 

on 11 August (day 119). Maximum linear displacement from point of release was 7.24 km 

downstream, and total cumulative point-to-point distance moved was 27.57 lan. 

Wild-caught 4-4. Released 18 April 1997 at South Basin Light Cove, Arizona (adjacent to VIP 

60) in the lower portion of Cottonwood Basin, immediately upstream from the Reservoir Canyon 

transition. Contacted on day 4 downstream 8.30 lan in deep water near WP 71 near the mouth of 

Davis Cove, Arizona. The fish was subsequently contacted on 13 occasions between days 14 

and 116. It remained between ViPs 69 and 71 and was detected on both sides ofthe river, in 

deep and shallow water. On 11 August (day 116) it was associated with wild-caught 3-3 near 

WP 69.5 in 5-6 m of water fewer than 15 m from the Arizona shore. Last contact was on 111 

August (day I 16). Maximum linear upstream displacement from point of release was 8.30 lan, 

and total cumulative point-to-point distance moved was 19.88 lan. 

Wild-caught 4-5. Released 16 April 1997 at Beaver Cove, Arizona, near WP 69.25 in the 

Reservoir Canyon portion ofthe lake. The fish moved downstream about 2.5 lan by day 6, when 

it was contacted in mid-chamiel near WP 68. It was detected on 12 subsequent occasions 

between WPs 67 and 71. It was found on both the Arizona and Nevada sides ofthe reservoir, in 

coves and open water, and both shallow and deep. The fish was associated with wild-caught 2-3 

on day 36 in deep water near WP 70.4. Last contact was on 16 June (day 62) inside the cove at 

Katherine Landing, Arizona. Maximum linear displacement from point of release was 

downstream 6.85 lan, and total cumulative point-to-point distance moved also was 32.97 lan. 

Wild-caught 4-6. Released 15 April 1997 at Katherine Powerline Cove, Arizona adjacent to 

WP 66.6 in the Reservoir Canyon portion ofthe lake. Last contact was on 17 April (day 3) 

adjacent to the Arizona shore near WP 60. Maximum linear displacement from point ofre1ease 

was downstream 7.5 lan, and total cumulative point-to-point distance moved also was 7.5 km. 

Wild-caught 5-6. Released 18 April 1997 at South Basin Light Cove, Arizona (adjacent to 

WP 60) in the lower portion of Cottonwood Basin, immediately upstream from the Reservoir 

Canyon transition. The fish apparently moved after release into mid-channel, where it either died 

or shed the tag. The immobile signal was contacted on 6 occasions (not shown in Table 2-J) at 

the same location (WP 60). 

II 
Spatio-temporal Aspects of Fish Locations 

Tagged bonytail tended to be found near shore more often than not. A..mong all contacts, 76% 

were associated with shoreline habitat; 24% were in deeper, open waters of the reservoir (Table 

3, Appendix A, Figures 2-11). All cove-reared fish contacts were near shore while wild-caught 

fish were found 70% along shore and the remainder were pelagic. 

Most contacts with tagged bonytail were during daylight or darkness; relatively few contacts 

were made during crepuscular periods (none during dawn and only 6 of 45 [13%J during dusk; 

see Table 3 for definitions). However, this may have been simply an artifact of when surveys 

were conducted rather than a true indication offish dispersal in space. Regardless, for both covereared and wild-caught bonytail, about half of all contacts were during daylight and half during 

darkness (Table 3). 

On the other hand, when day and shore orientation are considered simultaneously there was a 

clear indication that wild-caught bonytail spend most ofthe daylight hours in deeper, open 

waters (73% of deep water contacts were during the day) and most of their night or low-light 

hours (69% of shore contacts were at night or during crepuscular periods) in shallow water along 

shore (Table 3). This observation was made repeatedly for several individuals (e.g., sonic codes 

2-4,2-5, and 3-3) and seemed a general pattern of behavior and habitat use. 

Table 3.	 Contacts (number of observations) with cove-reared and wild-caught, sonic tagged 

bonytail in Lake Mohave, Arizona-Nevada, relative to time of day and proximity to 

shore, 14 May to 29 July 1996. 

Number of Observations 

Near shore Deep water 

Time of daya cove wild cove wild Totals 

Dawn 0 0 0 0 0 

Day 4 8 0 8 20 

Dusk 1 5 0 0 6 

Night 3 13 0 3 19 

Totals	 8 26 0 11 45 

Dawn = 0430-0559 hrs MST, Day = 0600-1859 hrs MST, Dusk = 1900-2029 hrs MST, 

Night = 2030-0429 hrs MST. 

Fish Captures Associated with Tagged Bonytail 

Tagged fish were used to direct net sets in an area used by sonic tagged bonytail along Arizona 

12 
shoreline near WP 67 (vicinity of Arrowhead Cove, Gasoline Ally, and Yoke Coves). Two, 

wild-caught bonytail (codes 2-4 and 2-5, see Appendix A, Tables 2 and 3) were located by 

telemetry in shallow water fewer than 20 m from shore on a gravel point between Gasoline Alley 

and Yoke Cove on the evening of 03 June, and again on 04 June 1996. Trammel nets (lOO-m 

long, 2.5 cm inter and 30-cm outer meshes) were set at about 2030 hrs on 04 June along the N 

points of Arrowhead and Yoke Coves (perpendicular to shore) and inspected at 1200 M, 0300, 

and 0600 hrs. A total of 4 unmarked, adult bonytail were captured in these two, shore-term sets. 

Fish were transported to Willow Beach National Fish Hatchery, Arizona and turned over to 

USFWS personnel. 

The capture of unmarked bonytail adults in an area used by marked fish is a significant result 

because it suggests a potential mechanism to enhance sampling efforts in behalf of brood fish 

acquisition. Additional sampling should be conducted in areas frequented by tagged bonytail 

(e.g., Arrowhead Cove-Gasoline Alley-Yolk Cove, Arizona area, Nine-Mile to Nellis Coves, 

Nevada, and as indicated by future telemetry work). 

CONCLUSIONS AND RECOMMENDATIONS 

Results of previous investigations (Minckley 1983, Marsh and Minckley 1992) are corroborated 

in that bonytail captures were along shallow, gravel points. However, most captures prior to 

1988 were during stormy periods in winter-early spring, and until the past decade little sampling 

has been conducted during warmer, late-spring to summer months. And, most earlier sampling 

was concentrated in the upper portion of Cottonwood Basin (for example, Carp Cove to 

Cottonwood East, Arizona and Tequila to Hog Farm Coves, Nevada). Sampling in these 

"traditional" areas now is augmented by efforts in the lower portions of the Reservoir Canyons 

(NFWG, unpublished data). Telemetry results clearly go hand in hand with existing information 

to provide a clear picture of bonytail habitat use, in a general sense, and should prove valuable in 

obtaining additional brood stock of the critically imperiled species. 

To this end we recommend that future attempts to capture additional wild fish be directed toward 

shallow points and gravel bars along the Arizona shoreline in the lowermost Reservoir Canyon 

zone of Lake Mohave. Other areas of the lake also deserve attention in this regard, since bOnyiail 

are not found exclusively in the lower lake. 

Wilile a recommendation of additional studies may seem trivial, important questions nonetheless 

remain without answers. Foremost is the need for information on post-stocking dispersal, 

distribution, and habitat use of hatchery-produced bonytail, which is necessary to provide 

management recommendations and to assess repatriation program success. Telemetry work can 

contribute to filling this information gap. 

13 
ACKNOWLEDGMENTS
 

B. E. Bagley, J. Best, T. Burke, S. Coleman, 1. Fenstermacher, D. K. Foster, M. & M. Gregor, C. 

Head, J. Healy, M. J. Horn, T. C. Inman, J. Kahl, G. W. Knowles, C. O. Minckley, D. Mueller, 

W. Pelle, A. Rollo, A. Sandoval, G. H. Schiffmiller, C. Sevidal, P. A. Sowka, C. Stutz, M. 

Thorsen, T. Tuchak, T. Wolters (representing ASU, USBR, USFWS, USGS, and USNPS) 

variously participated in fish collection, surgery, and tracking and provided needed support - all 

are thanked for their efforts. T. Chart and C. Minckley reviewed the report. Work was 

performed under permitting authority of Arizona Game and Fish Department, Phoenix; U.S. Fish 

and Wildlife Service, Albuquerque New Mexico; and U.S. National Park Service - Lake Mead 

National Recreation Area, Boulder City, Nevada and funded by USGS-BRD. 

REFERENCES 

Dill, W. A. 1944. The fishery of the lower Colorado River. California Fish and Game 30: 109­

211. 

Foster, D. K., P. C. Marsh, and G. Mueller. 1997. Bonytail chub telemetry in Lake Mohave, 

iuizona and Nevada. Proceedings of the Desert Fishes Council 29(l997). 

Fradkin, P. L. 1968. A River No More. The Colorado River and the West. University of 

Arizona Press, Tucson. 360 p. 

Holden, P. B. 1980a. Gila elegans Baird and Girard Bonytail chub. Page 167 in D. S. Lee, C. 

R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister, and J. R. Stauffer, Jr. (editors).
 

Atlas of North American Freshwater Fishes. North Carolina Biological Survey, Raleigh.
 

Holden, P.B. 1980b. Xyrauchen texanus (Abbott) Humpback sucker. Page 435 in D. S. Lee, 

C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister, and 1. R. Stauffer, Jr. (editors). 

Atlas ofNorth American Freshwater Fishes. North Carolina Biological Survey, Raleigh. 

Holden, P. B. and W. L. Minckley. 1980. Gila cypha Miller Humpback chub. Page 165 in D.S. 

Lee, C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister, and J. R. Stauffer, Jr. 

(editors). Atlas of North American Freshwater Fishes. North Carolina Biological Survey, 

Raleigh. 

Johnson, J. E. 1987. Protected fishes of the U.S. and Canada. American Fisheries Society,
 

Bethesda, MD. 47 p.
 

14 
Knowles, G. W. 1997. Movements of adult razorback suckers Xyrauchen texanus in Lake 

Mohave, Arizona-Nevada. Master of Science Thesis, Arizona State University, Tempe. 

Marsh, P. C. 1994. Abundance, movements, and status of adult razorback sucker in Lake 

Mohave, Arizona and Nevada. Proceedings ofthe Desert Fishes Council 25(1993):65. 

Marsh, P. C. 1996. Bonytai1 Gila elegans stocking records for Lake Mohave, Arizona and 

Nevada. Report, U.S. Bureau of Reclamation, Boulder City NV, Order Number 1425-96­

PG-30-07870. Arizona State University, Tempe. 

Marsh, P. C. 1997a. Age estimation from otoliths of bonytail chub Gila elegans from Lake 

Mohave, Arizona and Nevada. Report, U.S. Fish and Wildlife Service, Parker AZ, Order 

Number 22340-5-0033. Arizona State University, Tempe. 

Marsh, P. C. 1997b. Sonic telemetry ofbonytail in Lake Mohave, Arizona and Nevada. Report, 

U.S. Geological Survey, Denver Colorado, Cooperative Agreement 1445-0009-94-1108, 

task 2. Arizona State University, Tempe. 

Marsh, P.c. 1997c. Razorback sucker monitoring in Lake Mohave, Arizona and Nevada, for the 

period 01 November 1995 to 31 October 1996. Report, U.S. Bureau of Reclamation, 

Boulder City, Nevada, order number 1425-97-PG-30-06390. Arizona State University, 

Tempe. 

Marsh, P. C. In press, b. Threatened fishes of the world: Xyrauchen texanus (Abbott), 1860 

(Catostomidae). Environmental Biology of Fishes. 

Marsh, P. C. In press, a. Threatened fishes of the world: Gila elegans Baird and Girard 1853 

(Cyprinidae). Environmental Biology of Fishes. 

Marsh, P. C. and W. L. Minckley. 1992. Status of bonytail (Gila elegans) and razorback sucker 

(Xyrauchen texanus) in Lake Mohave, Arizona-Nevada. Proceedings of the Desert Fishes 

Council (1991): 18-23. 

McAda, C. W. and R. S. Wydoski. 1980. The razorback sucker, Xyrauchen texanus, in the 

upper Colorado River basin, 1974-1976. U.S. Fish and Wildlife Service Technical Paper 

99: 1-15. 

Miller, R. R. 1961. Man and the changing fish fauna ofthe American southwest. Papers ofthe 

Michigan Academy ofArts, Science and Letters 46: 365-404. 

15 
Miller, W. H., H. M. Tyus, and C. A. Carlson. 1982. Fishes ofthe upper Colorado River 

system: Present and future. American Fisheries Society, Bethesda, MD. 131 pages. 

Minckley, W. L. 1973. Fishes of Arizona. Arizona Game and Fish Department, Phoenix. 293 

pages. 

Minckley, W. L. 1979. Aquatic habitats and fishes of the lower Colorado River, southwestern 

United States. U.S. Bureau of Reclamation Contract 14-06-300-2529, Arizona State 

University, Tempe. 478 pages. 

Minckley, W. L. 1985. Native fishes and natural aquatic habitats of U.S. Fish and Wildlife 

Service Region II, west of the continental divide. U.S. Fish and Wildlife Service 

Interagency Personnel Act Agreement, l\.rizona State University, Tempe. 185 pages. 

Minckley, W. L. 1983. Status ofthe razorback sucker, Xyrauchen texanus (Abbott), in the lower 

Colorado River basin. Southwestern Naturalist 28: 165-187. 

Minckley, W. L. 1991. Native fishes of the Grand Canyon region: An obituary? Pages 124-177 

in Colorado River Ecology and Dam Management. National Academy Press, 

Washington, DC. 

Minckley, W. L. and J. E. Deacon, editors. 1991. Battle Against Extinction: Native Fish 

Management in the American West. University of Arizona Press, Tucson. 517 pages. 

Mueller, G. and P. C. Marsh. 1995. Bonytail and razorback sucker in the Colorado River basin. 

Pages 324-326 In E. T. LaRoe, G. S. Farris, C. E. Puckett, P. D. Doran and M. J. Mac, 

editors. Our living resources: A report to the nation on the distribution, abundance, and 

health of U.S. plants, animals, and ecosystems. U.S. Department of the Interior, National 

Biological Service, Washington, D.C. 

Tyus, H. M. 1991. Ecology and management of Colorado squawfish. Pages 379-402 in W.L. 

Minckley and J. E. Deacon, editors. Battle Against Extinction: Native Fish Management 

in the American West. University ofArizona Press, Tucson. 

Tyus, H. M. and K. A. Karp. 1989. Habitat use and streamflow needs ofrare and endangered
 

fishes, Yampa River, Colorado. U.S. Fish and Wildlife Service Biological Report 89(14):
 

1-27.
 

U.S. Fish and Wildlife Service (USFWS). 1980. Aquatic study of the lower Colorado River. 

U.S. Water and Power Resources Service Contract 9-07-30-X0066, U.S. Fish and
 

Wildlife Service, Phoenix, Arizona. 278 pages.
 

16
 
U.S. Fish and Wildlife Service (USFWS).	 1982. Part 2, Colorado River fishery project, final 

report fieldinvestigations.· U.S. Bureau of Reclaination Contract 9-06-40-L-I016, U.S. Fish 

and Wildlife Service, Salt Lake City, Utah. 365 pages. 

Worster, D. 1985. Rivers of Empire. Water, Aridity and the Growth of the American West. 

Pantheon Books, New York. 402 pages. 

17 
APPENDIX A 

1996
 

Telemetry Tables and Figures
 

18
 
Appendix A, Table 1. Individual tracking summaries for sonic telemetry ofbonytail in Lake 

Mohave, Arizona and Nevada, 14 May to 12 August 1996. Fish are individually identified by 

their source (i.e., pond-reared or wild-caught) and two digit sonic tag code number (see Table 1 

for additional information). Waypoints (WP) as in Figure 1. Distances in km are between 

successive contact points (Pt to pt), net displacement from release site (net), and cumulative 

distance traveled, the sum of all point to point distances (cumulative). 

A. Cove reared 2-2 Released 23 May 1996 at 1st cove N of Copper Basin Cove NV 

Date Day Location Pt to pt Net Cumulative 

23 May 1st N 116 no post-release contact 

B. Cove-reared 2-3. Released 14 May 1996 at 1st cove N of Carp Cove AZ 

Date Day Location Pt to pt Net Cumulative 

14 May lIstN Carp 

21 May 8 WP 36 5.6 5.6 5.6 

18 June 36 WP 17.5 35.3 40.9 40.9 

19 June 37 WP 19.3 3.8 37.1 44.7 

28 June 46 WP 9.3 17.9 55.0 62.6 

09 July 57 WP 17 12.4 42.6 75.0 

16 July 64 WP 17 0 42.6 75.0 

24 July 72 WP 17 0 42.6 75.0 

C. Wild-caught 2-4. Released 16 May 1996 at 1st cove N of.Copper Basin Cove NV 

Date Day Location Pt to pt Net Cumulative 

16 May 1 IstN 116 

23 May 8 WP 35 0.9 0.9 0.9 

03 June 19 WP67.5 31.5 31.5 32.4 

04 June 20 WP 67.5 0.8 31.3 33.2 

05 June 21 WP 68 0 31.3 33.2 

12 June 28 WP68.3 0.5 31.9 33.7 

17 June 33 WP 69 1.2 33.1 34.9 

25 June 41 WP68 1.8 31.3 36.7 

27 June 43 WP 68.3 0.6 31.9 37.3 

30 June 46 WP 68 1.2 33.1 38.5 

09 July 55 WP 70.3 2.2 35.3 40.7 

17 July 63 WP 69.7 2.0 33.3 42.7 

22 July 68 WP 69.7 2.0 33.3 42.7 

29 July 75 \VP 69.7 2.0 33.3 42.7 

19
 
D. Wild-caught 2-5. Released 16 May 1996 at 1st cove N of Copper Basin Cove NV 

Date Day Location Pt to pt Net Cumulative 

16 May 1 1st N 116 

30 May 15 WP68 31.3 31.3 31.1 

03 June 19 WP67 1.6 32.9 32.9 

04 June 20 WP68 1.6 31.3 34.5 

05 June 21 WP68 0 31.3 34.5 

12 June 28 WP 68.3 0.4 31.7 34.9 

17 June 33 WP 68.3 1.5 33.2 36.4 

E. Wild-caught 2-6. Release 15 May 1996 across from Cotton Wood Cove NYT. 

Date Day Location Pt to pt Net Cumulative 

15 May 1 Acr CWCM 

19 May 5 WP71 32.6 32.6 32.6 

20 May 6 WP70 2.1 30.5 33.7 

22 May 8 WP70 0 30.5 33.7 

30 May 16 WP70.5 0.9 31.4 34.6 

F. Wild-caught 3-3. Released 16 May 1996 at Levi Cove AZ. 

Date Day Location Pt to pt Net Cumulative 

16 May 1 Levi Cove 

19 May 4 WP 53 7.8 7.8 7.8 

20 May 5 WP52 1.5 7.9 9.3 

22 May 7 WP 53 1.5 8.1 10.8 

30 May 15 WP54 2.1 9.9 12.9 

03 June 19 WP53 1.8 8.1 ·14.7 

05 June 20 WP53 0 8.1 14.7 

12 June 28 WP 47-52 1.8 7.4 16.5 

",.., 17 June .:u WP 53.3 1.6 8.8 18.1 

27 June 43 WP 53.3 0 8:8 18.1 

G. Cove-reared 3-4. Release 14 May 1996 at 15t cove N of Carp Cove AZ 

Date Day Location Pt to pt Net Cumulative 

16 May 1 1st N 116 no post-release contact 

H. Wild-caught 3-5. Release 16 May 1996 at 1st cove N of Copper Basin Cove NY. 

Date Day Location Pt to pt Net Cumu1ative 

16 May 1 1st N 116 

18 May .)" WP34 2.4 2.4 2.4 

20 May 5 WP62 24.0 21.6 26.4 

22 May 7 WP68 10.3 31.9 36.7 

30 May 15 WP68 0 31.9 36.7 

20
 
L Cove-reared 4-4. Release 15 May '1996 at North Arizona Juvenile backwater AZ 

Date Day Location Pt to pt Net Cu..'Uulative 

16 May 1 North AJ 

12 June 29 WP 58 4.0 4.0 4.0 

J. Cove-reared 5-5. Release 14 May 1996 at 1st cove N of Carp Cove AZ 

Date Day Location Pt to pt Net Cumulative 

14 May 1 1st N Carp 

21 May 8 WP 29 15.3 15.3 15.3 

23 May 10 WP 36 11.5 5.1 26.8 

21 
12 June 

Lake Mohave	 17 June 

Bonytail Tag No. 2-4	 17 July, 22 July,
 

29 JUly
 465 M/Wild
 

9 July
 

- Zone 1. Reservoir Canyon 

- Zone 4: Interface Zone Davis Dam 

lone 2: Cottonwood Basin 

!

N 

23 May	 l. 

Released: lsI cove N. of 

river mile 116. 

16 May '96 30May~ 27 June 25 June • 

Figure 2. Map of Lake Mohave, Arizona and Nevada, showing locations of bonytaij' Gila elegkns determined by sonic telemetry 

between 14 May to 12 August 1996. Release location and date, and loeation(s) and date(s) of subsequent telemetry contacts 

indicated on map. Wild-caught fish, tag number 2-4, total length 46.5 em, sex M. 

o 5km I ! 
12 June 

Lake Mohave 17 June

Bony tail Tag No. 2-5
 

430 M/Wild
 

- Zone 1. Reservoir Canyon 

- Zone 4: Interface Zone Davis Dam 

A Zone 2: Cottonwood Basin 

N 

J
 

Released: 1sl cove N. of 
 

river mile 116. 16 May"96:
 

30 May \. 

Figure 3. Map of Lake Mohave, Arizona and Nevada, shOWing locations of bonytail Gila elegans determined by sonic telemetry 

between 14 May to 12 August 1996. Release location and date, and location(s) and date(s) of subsequent telemetry contacts 

indicated on map. Wild-caught fish, tag number 2-5. total length 43.0 em, sex M. 

o I 5kmI 
Zone ). Reservoir Canx.0n 

- Zone 4: Interface Zone 

Releucd; ACfOlII from
 Lake Mohave Col1onwood Cove.
 

15 May '96
 Bonytail Tag No. 2-6 ... Zone 3: Castle Cliff Basin
 

462 MlWild
 

-

N 

1 

Zone 2: Cottonwood Basin 

-

Davis Dam 

20 May 

. """ 30 MHy 

19 May 

Figure 4. Map of Lake Mohave, Arizona and Nevada, showing locations of bonytaij Gila elegans determined by sonic telemetry 

between 14 May to 12 August 1996. Release location and date, and localion(s) and date(s) of subsequent telemetry contacts 

indicated on map. Wild-caught fish, tag number 2-6, total length 46.2 em, sex M. 

o 5km 

I I 
Zone 3: Castie Cliff Basin 

Lake Mohave	 RelelL$ed: L~vi COy 

16 MIIy 96 Bonytail Tag No. 3-3 

461 F/Wild 

- Zone I' Reservoir Canyon 

- Zone 4: Interface Zone Davis Dam 

J2 June 20 May 

19 May , 

27 June 22 May 

- Zone 2: Cottonwood Basin 

!

N 

o 

I 5kmI 

Figure 5, Map of Lake Mohave, Arizona and Nevada, showing locations of bonytail Gila efegans determined by sonic telemetry 

between 14 May !o 12 August 1996. Release location and date, and location(s) and date(s) of subsequent telemetry contacts 

indicated on map Wild-caught fish, tag number 3-3, total length 46.1 cm, sex F. 
Lake Mohave
 

Bonytail Tag No. 3-5
 

455 M/Wild 

30 May 

- Zone 1 Reservoir Canyon 

- Zone 4: Interface Zone Davis Dam 

- Zone 2: Cottonwood Basin 

""1' 20 May 

1 

N 18May ---. jJ 

Released: Ist cove N. of 

river mile 116. 16 May '96 

I 

Figure 6. Map of Lake Mohave, Arizona and Nevada, showing locations of bonytail Gila elegans determined by sonic telemetry 

between 14 May to 12 August 1996. Release location and date, and location(s) and date(s) of subsequent telemetry contacts 

indicated on map. Wild-caught fish, tag number 3~5, total length 45.5 em, sex M. 

o 5km I I 
Lake Mohave 

Bonytail Tag No. 2-2 

355 F/Cove 

N 

1 

Zone 4: Interface Zone 

Released: 1st cove N. of 

river mile 116. 

23 May '96 

- Zone 2: Cottonwood Basin 

- Zone I: Reservoir Canyon 

Davis Dam 

o 

I 5kmI 

Figure 7. Map of Lake Mohave, Arizona and Nevada, showing locations of bonytail Gila elegans determined by sonic telemetry 

between 14 May to 12 Augusl 1996. Release location and date, and location(s) and date(s) of subsequent telemetry contacts 

indicated on map Cove-reared fish, tag number 2-2, total length 35.5 em, sex F. 
Released: Ist cove: N. of 

Carp Cove. 

Zone 3: Castle Cliff Basin 

Lake Mohave 

Bonytail Tag No. 2-3 

363 M/Cove 

- Zone 4: Interface Zone 

---28June 

N 

1 --- 18 June 

o 5km , I 

14 May '96 

- Zone I Reservoir Canyon 

Davis Dam 

:"" Zon,e 2: Cottonwood Basin 

. 21 May 

Figure 8. Map of Lake Mohave, Arizona and Nevada, showing locations of bonytail Gila elegans determined by sonic telemetry 

between 14 May to 12 August 1996. Release location and dats, and loeation(s) and date(s) of subsequent telemetry contacts 

indicated on map. Cove-reared fish, tag number 2-3, total length 36.6 em, sex M. 
- lone I: Reservoir Canyon 

Released: Isl cove N. i;:Jf. Lake Mohave Carp Cove. 14 May '96 

Bonytail Tag No. 3~4 .... Zone 3: Castle Cliff Basin 

396 F/Cove 

lone 4: Interface lone Davis Dam 

- Zone 2: Cottonwood Basin 

N 

1 

o ! 5km, 

Figure 9. Map of Lake Mohave, Arizona and Nevada, showing locations of bonytail Gila elegans determined by sonic telemetry 

between 14 May to 12 August 1996. Release location and dale, and loeation(s) and date(s) of subsequent telemetry contacts 

indicated on map. Cove-reared fish, lag number 3-4, total length 39.6 em, sex F. 
Lake Mohave 

Bonytail Tag No, 4-4 

422 FICove 

N 

1 

- Zone 4: Interface Zone 

Released: North AJ _,,+----­

15 May '96 

- Zone 2; Cottonwood Basin 

Zone 1: Reservoir Canyon 

Davis Dam 

\ 12 June 

o 5km 

t I 

Figure 10. Map of Lake Mohave, Arizona and Nevada, showing locations of bonytail Gila elegans determined by sonic teleme!ry 

between 14 May to 12 August 1996. Release location and date, and location(s) and date(s) of subsequent telemetry contacts 

indicated on map Cove-reared fish, tag number 4-4, total length 42,2 em, sex F. 
- Zone 1. Reservoir Canyon 

Released: 1st cove N. of Lake Mohave Carp Cove. 14 May '96 

Bonytail Tag No. 5-5 .... Zone 3: Castle Cliff Basin 

427 FICove 

- Zone 4: Interface Zone Davis Dam 

21 May .... A~

- Zone 2: Cottonwood Basin 

! 

N 

23 May ,}. 

o 5km 

I J 

Figure 11. Map of Lake Mohave, Arizona and Nevada, showing locations of bonytail Gila elegans delermined by sonic lelemetry 

between 14 May to 12 August 1996, Release location and date, and location(s) and date(s) of subsequent telemetry contacts 

indicated on map Cove-reared fish, lag number 5-5, lolallength 42.7 em, sex F. 
APPENDIXB
 

1997
 

Telemetry Tables and Figures
 

22
 
Appendix B, Table 1. Individual tracking summaries for sonic telemetry of bonytail in Lake 

Mohave, Arizona and Nevada, 02 April to 28 September 1997. Fish are individually identified 

by their source (i.e., pond-reared or wild-caught) and two digit sonic tag code number (see Table 

1 for additional information). Waypoints (WP) as in Figure 1. Distances in km are between 

successive contact points (Pt to pt), net displacement from release site (net), and cumulative 

distance traveled, the sum of all point to point distances (cumulative). 

A Pond-reared 3-4. Release 02 April 1997 at Cottonwood Cove NY 

Date Day Pt to pt Net Cumulative 

02 Apr 1 0 0 0 

13 Apr 12 1.4 1.4 1.4 

13 Apr 12 0.6 1.6 2.0 

Last contact: WP 38.75 at Airport Cove AZ 

B. Pond-reared 3-5. Release 02 April 1997 at Cottonwood Cove NY 

Date Day Pt to pt Net Cumulative 

02 Apr 1 o 0 0 

No post-release contact 

C. Pond-reared 3-6. Release 02 April 1997 at Cottonwood Cove NY 

Date Day Pt to pt Net Cumulative 

02 Apr 1 o 0 0 

No post-release contact 

D. Wild-caught 2-3. Release 15 April 1997 at Katherine Powerline Cove AZ 

Date Day Pt to pt Net Cumulative 

15 Apr 1 0 0 0 

21 Apr 7 4.8 4.8 4.8 

01 May 17 3.0 1.8 7.8 

01 May 17 0.4 1.5 8.2 

09 May 25 0.9 2.4 9.2 

09 May 25 0.3 2.6 9.4 

09 May 25 0.7 3.2 10.1 

09 May 25 0.8 2.5 10.9 

12 May 28 1.1 1.5 12.0 

Date Day Pt to pt Net Cumulative 

21 May 37 5.4 6.8 17.3 

21 May 37 5.7 1.2 23.0 

22 May 38 0.4 0.8 23.4 

22 May 38 0.3 0.5 23.7 

27 May 43 3.6 4.1 27.4 

27 May 43 0.6 4.7 28.0 

23 
02 June 49 1.5 6.2 29.5 

16 June 63 0.4 6.6 30.0 

23 June 70 0.2 6.7 30.1 

03 July 80 2.2 4.7 32.4 

Last contact: 0.17 kIn N ofN point at Telephone Cove .1\2 

E. Wild-caught 2-4. Release 15 April 1997 at Katherine Powerline Cove AZ 

Date Day Pt to pt Net Cumulative 

15 Apr 1 0 0 0 

01 May 17 5.7 . 5.7 5.7 

01 May 17 2.6 3.0 8.3 

07 May 23 0.9 2.2 9.2 

09 May 25 6.1 8.4 15.3 

09 May 25 2.9 7.2 18.2 

12 May 28 1.4 5.7 19.6 

12 May 28 0.3 5.5 19.9 

21 May 37 0.3 5.8 20.2 

22 May 38 4.9 1.0 25.1 

14 June 61 4.7 5.6 29.7 

23 June 70 1.4 5.3 31.1 

21 July 98 0.2 5.4 31.3 

Last Contact: Back (east end) of Telephone Cove AZ 

F. Wild-caught 3-3. Release 15 April 1997 at Katherine Powerline Cove AZ 

Date Day Pt to pt Net Cumulative 

15 Apr 1 000 

21 Apr 7 5.6 5.6 5.6 

01 May 17 2.6 3.1 8.2 

01 May 17 0.8 2.4 9.0 

07 May 23 0.1 2.3 9.0 

09 May 25 0.1 2.1 9.2 

09 May 25 0.3 2.5 9.5 

09 May 25 0.4 2.7 9.9 

12 May 28 0.7 2.1 10.6 

24
 
Date Day Pt to pt Net Cumulative 

21 May 37 5.2 7.2 15.8 

21 May 37 3.2 4.1 19.0 

27 May 43 1.7 2.4 20.7 

02 June 49 0.3 2.4 20.9 

14 June 61 0.4 2.6 21.4 

16 June 63 1.4 4.0 22.7 

23 June 70 1.8 2.3 24.5 

03 July 80 1.7 4.0 26.2 

14 July 91 0.8 4.8 27.0 

14 July 91 0.4 4.8 27.3 

21 July 98 0.1 4.9 27.4 

11 Aug 119 0.2 5.0 27.6 

Last contact: N point of Telephone Cove AZ 

G. Wild-caught 4-4. Release 18 Apr 1997 at South Basin Light Cove AZ 

Date Day Pt to pt Net Cumulative 

18 Apr 1 0 0 0 

21 Apr 4 8.3 8.3 8.3 

01 May 14 3.6 4.0 11.9 

01 May 14 0.9 4.8 12.7 

09 May 22 0.9 4.9 13.6 

09 May 22 0.9 5.6 14.5 

12 May 25 0.4 6.1 14.9 

21 May 34 0.4 5.7 15.3 

21 May 34 0.3 5.8 15.6 

27 May 40 1.7 4.1 17.3 

27 May 40 1.0 5.1 18.3 

16 June 60 0.3 4.8 18.6 

14 July 88 0.3 4.9 18.9 

21 July 95 0.8 5.4 19.7 

11 Aug 116 0.2 4.8 19.9 

Last contact: N point of Telephone Cove AZ 

H. Wild-caught 4-5. Release 16 April 1997 at Beaver Cove AZ 

Date Day Pt to pt Net Cumulative 

16 Apr 1 0 0 0 

21 Apr 6 2.5 2.5 2.5 

01 May 16 4.2 6.6 6.6 

07 May 22 4.2 2.5 10.8 

25 
Date' Day Pt to pt Net Cumulative 

09 May 24 0.7 2.4 11.5 

12 May 27 0.9 3.2 12.4 

12 May 27 0-3 3.6 12.7 

21 May 36 3.0 6.8 15.7 

21 May 36 0.4 6.4 16.1 

22 May 37 2.1 5.1 18.2 

27 May 42 3.6 3.2 21.8 

02 June 48 2.6 5.8 24.4 

14 June 60 3.8 2.1 28.2 

16 June 62 4.8 6.9 33.0 

Last contact: Inside Katherine Landing AZ 

1. Wild-caught 4-6. Release 15 April 1997 at Katherine Powerline Cove AZ 

Date Day Pt to pt Net Cumulative 

15 Apr 1 0 0 0 

17 Apr 3 7.5 7.5 7.5 

Last contact: WP 60 (FLR "2") AZ 

Wild-caught 5-6. Release 18 April1997 at South Basin Light Cove AZ 

Date Day Pt to pt Net Cumulative 

18 Apr 1 000 

14 July 88 0 0 0 

Last contact: WP 60 AZ side (no post release movement detected) 

26
 
Lake Mohave Bonytail Movements 

River Mile 1 - 6 


 4/15/97------'~~/I~
 I '? 

5/22/97~~~- ~~/12/97

5/22/97 5/1/97

5/21/97 

5/1/97 

5/9/97 5/9/97 

--5/9/97 

5/9/97 5/27/97 

5/27/97 7/3/97 

6/2/97 4/21/~

6/16/97 6/23/97

5/21/97 

N
 

Figure 2. Map of lower Lake Mohave, Arizona and 

Nevada, showing post-release locations and dates for 

wild-caught bonytail 2-3 determined by sonic telemetry 

during spring-summer 1997. See Table 1 for release 

data. 

s 
Lake Mohave Bonytail Movements 

River Mile 1 - 6 

4/15/97
 

5/22/97
 

5/7/97 

5/1/97 

7/14/97
 

/Z) 

,JS 

~l

4

E
 

i 

? 

o 

~~

O~'1.~

2 
 .~
 .~	 6/23/97 

7/21/97 

6/14/97----&5~_~5/12/97 

5/1/97 '~5/12/97

5/21/97 r' 5/9/97 

~5/9/97 r; , 

1 0 1 2 3 4 Kilometers ~i~~~~__~~~.....! 

N 

Figure 3. Map of lower Lake Mohave, Arizona and 

Nevada, showing post-release locations and dates for 

wild-caught bonytail 2-4 determined by sonic telemetry 

during spring-summer 1997. See Table 1 for release 

data. 

s
 
Lake Mohave Bonytail Movements 

River Mile 1 - 6 ' 

1 o 1 2 3 4 Kilometers 

5/9/97 

4/15/97---~--''9/_-

~~< 

( 

?:!.. 

8/12197 

5/1/97 

7/3/97 

5/21/97 

~=t------c~~7/14/97

7/21/97 

8/11/97 

4/21/97 

N
 

Figure 4. Map of lower lake Mohave, Arizona and 

Nevada, showing post-release locations and dates for 

wild-caught bonytail 3-3 determined by sonic telemetry 

during spring-summer 1997. See Table 1 for release 

data. 

s
 
Lake Mohave Bonytail Movements 

River Mile 20 - 22 

\ 

~---~)

4/13/97 

4/13/97 t! 

1 o 1 

N
 

Figure 5. Map of lower Lake Mohave, Arizona and 

Nevada, showing post-release locations and dates for 

wild-caught bonytail 3-4 determined by sonic telemetry 

during spring-summer 1997. See Table 1 for release 

data. s 
Lake Mohave Bonytail Movements 

River Mile 1 - 6 

4/15/97 .d'~

.2, 

<-' 

4 

6/16/97-

5/1/97 5/27/97 7/14/97 

8/11/97

6/23/9,~ 5/27/97 

5/1/97~\ _ 5/21/97 7/21/97 

5/9/97 5/12/97

5/9/97 J 

S- 
 

5/21/9 :S ~4/21197

1 « ( 

1 o 1 2 3 

N 

Figure 6. Map of lower Lake Mohave, Arizona and 

Nevada, showing post-release locations and dates for 

wild-caught bonytail 4-4 determined by sonic telemetry 

during spring-summer 1997. See Table 1 for release 

data 

s
 
Lake Mohave Bonyta.il Movements 

River Mile 1 - 6 

6/14/97 

5/7/97 

4/21/97 

5/27/97 

, 

5/9/97 

( 

5/12/97~7 

5/12/97 0,? 

r-F , 

{ 

~J'0'1t.., 5/22/97

6/2/97 J ·0, ~\./5\ 6/16/97 

5/21/97~~ .
 

5/1/97 / 7:;;~ 5/21/97
 

1 o 1 2 3 

Figure 7. Map of lower Lake Mohave, Arizona and 

Nevada, showing post-release locations and dates for 

wild-caught bonytail 4-5 determined by sonic telemetry 

during spring-summer 1997. See Table 1 for release 

data. 

N 

s