9586

• UCREFRP Catalog Number: 9586
• Author: Desert Fishes Council.
• Title: Proceedings of the Desert Fishes Council Volume XXVI 1994 Annual Symposium.
• USFW Year: 1994.
• USFW - Doc Type: Furnace Creek, CA.
• Copyright Material: NO

PROCEEDINGS OF THE DESERT FISHES COUNCIL, 1994 SYMPOSIUM VOLUME XXVI - published 1995
FLAGSTAFF FISHERY RESOURCE OFFICE - The Flagstaff office conducted two spring and two summer
sampling trips into the Little Colorado River to assess/monitor stream habitat and habitat use by humpback chub
and other native fishes. Humpback chub appeared to commence spawning in mid-winter; appearance of a broad
range of YOY fishes suggested a protracted spawning season. Surveys were also conducted in Grand Canyon
tributaries (Pavia, Bright Angel, Shinumo; Tapeats, Deer, Kanab, Havasu) to assess/monitor stream habitat and
habitat use by native fishes.
A pilot study of cryopreservation of razorback sucker sperm was also carried out during the Lake Mohave
roundup, March 1994. Successfully fertilized eggs in the field with cryopreserved milt. Conducted pilot study on
cryopreservation of bonytail chub sperm at Dexter NFH in May; eggs were successfully fertilized with
cryopreserved sperm. We are preparing to conduct a pilot study on humpback chub in 1995.
Finally, a draft final report on GCES contracted studies was completed on June 30. A final version is expected
by 1 October.'
PARKER FISHERY RESOURCE OFFICE - Razorback suckers - To date, a total of 90 razorback suckers have
been released into Colorado River waters from isolated growout facilities. This includes 86 from the high levee
pond growout facility at Cibola NWR and 4 from Pittsburgh Point Cove on Lake Havasu. During a two week period
in March 230 razorback suckers were taken in the annual research on Lake Mohave by Service personnel. 24%
were recaptures.
During March-April an estimated 110,000 razorback sucker eggs were fertilized and delivered to Willow
Beach National Fish Hatchery. Currently, it is estimated that 10,000 fish ranging from one to 12 inches are being
held at the hatchery. These fish were collected from several different areas on Lake Mohave at different times of
the month. One to one matings were performed and a standard quanity of eggs were taken (25 in]) each time. These
fish were produced to determine if retrofitting of this hatchery to a warm water facility would make it feasible to
produce native fish.
Additionally, during February and March personnel from the Service participated in harvesting wild razorback
sucker larvae from Lake Mohave with other members of the native fish group. In conjunction with this 1200 larvae
were transferred to the Parker FRO and held and reared to replenish the broodstock at Dexter NFH. Two hundred
two-four inch fish were delivered to Dexter in October 1994.
During 1994 no bonytail chubs were produced from the Office Cove as it was breached shortly after
establishment allowing fish to escape into the lake and non-indigenous fish to enter the cove. When it was poisoned,
no native fish were taken. However, a total of 58 adult bonytail chub have been removed from the Hassayampa
River Preserve (The Nature Conservancy) and released into Lake Havasu during 1994. Six thousand 1-2 inch fish
were produced from 44,000 fry provided to the Parker FRO in April of 1994 and introduced into two facilities on
Lake Havasu.
During 1994, as part of the efforts of the Lake Havasu Native Fish Project in partnership with Bureau of Land
Management and other agencies, three additional barriered habitats were developed on Lake Havasu for native fish.
Additionally, a isolated habitat was developed adjacent to Lake Havasu. Two facilities in operation on Lake Havasu
in 1993 were also re- poisoned to prepare them for receiving bonytail chubs in October.
One isolated facility has also been developed on Imperial NWR. In addition to this four ponds on the La Paz
County golf course have been developed for native fish.
The Pinetop Fish Health Office examined fishes for disease from No Entry Cove and from the Hassayampa
River Preserve. Nothing of significance was found. However, upon examination of two bonytail chub which died
subsequent to the initial examination, the Asian tapeworm was found.
In summary, twelve native fish isolated habitats are in place along the lower Colorado River, below Davis
Dam. These include the following sites on or adjacent to Lake Havasu: Pittsburgh Point Cove No Entry Cove Office
Cove - Bill Williams River NWR Twin Cove South - Havasu NWR Twin Cove North - Havasu NWR Bulkhead
Cove. In addition:
Four ponds on the La Paz County golf course High Levee Pond - Cibola NWR Hidden Lake - Imperial NWR.
Currently all are stocked with bonytail chub produced by Dexter National Fish Hatchery and Technology Center.
The total acreage is estimated at 25 acres.
Besides these activities, Parker FRO has produced the Little Colorado Spinedace Recovery Plan which was
published in the Federal Register on 23 September 1994. The Lower Basin Management Plan for Indigenous Big
River Fishes was also produced and is currently under review.
11