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ABSTRACTS OF PRESENTATIONS IN ORDER PRESENTED
<br />de la seccifin siete. La informaci6n recopilada de estos esfuerzos esta siendo incorporada en el EIS, incluyendo una
<br />opinion biol6gica que sera escrita sobre la alternativa preferida. El acuerdo costo-compartido con el Servicio Forestal
<br />proporciono financiamiento para dos actividades. La primera fue un muestreo de distribuci6n, abundancia, y use de
<br />habitat del charal de espina en extensiones de arroyos designados como habitats crlticos en los bosques de Coconino y
<br />Apache-Sitgreaves. La segunda fue una evaluaci6n actual de los peces en el arroyo Tonto del Bosque Nacional Tonto.
<br />HEINRICH, J. E.*; SJOBERG, J. C. (Nevada DepaAment of Wildlife, Region III, 4747 Vegas Drive, Las Vegas, Nevada 89108)
<br />Status and evaluation of Nevada fishes / Situaci6n actual y evaluaci6n de los peces de
<br />Nevada
<br />KEYWORDS: Nevada; Devil's Hole; poolfish; springfish; spinedace; Ash Meadows; Virgin River; razorback sucker;
<br />tui chub
<br />ABSTRACT
<br />The Nevada Department of Wildlife's Endemic Fish Program has responsibility for the monitoring, status
<br />evaluation, and program coordination for 75 species and sub-species of endemic, non-game fish within the geographic
<br />boundaries of the state of Nevada. Currently the program is staffed with one full-time biologist stationed in Las Vegas.
<br />The primary concentration of effort at this time has been on the implementation and coordination of Section 6 funded
<br />projects for federally listed species, with inventory and evaluation of state-listed sensitive species being conducted on a
<br />time-available basis. Nevada currently has 17 species or subspecies of federally Endangered fish, an additional 5 which
<br />are Threatened, and 33 which are candidates for listing.
<br />Major activities during 1991/1992 included the following, species: Cyprinodon diabolis, Empetrichthys latos latos,
<br />Crenichthys baileyi grandis, Crenichthys baileyi baileyi, Gila robusta jordani, Lepidomeda albivallis, Plagopterus
<br />argentissimus, Gila robusta seminuda, Xyrauchen teXanus, Crenichthys nevadae, Relictus solitarius, Gila bicolor ssp.,
<br />Rhinichthys osculus ssp., Crenichthys baileyi thermophilus.
<br />1. Devil's Hole pupfish, Cyprinodon diabolis - Population counts were conducted at Devil's Hole in April and
<br />October. The combined spring dive/surface counts in October 1991, averaged 472 fish. This is comparable to previous
<br />fall counts of 525 (1988) and 441 (1986). Population counts conducted in April, 1992 generated a combined dive/surface
<br />count average of 272. This compares favorably with previous spring counts of 239 (1988), 151 (1987), and 152 (1985).
<br />Since 1988, numbers of devils Hole pupfish have stabilized at an annual peak of around 500 fish.
<br />On June 28, 1992, Devils Hole was rocked by a serious earthquake that resulted in a 6-8 inch drop in water level.
<br />Counts have been made by University of Nevada, Las Vegas personnel monthly since August. Initial counts showed the
<br />population numbers still remaining stable.
<br />Surface and dive counts were also conducted in spring and fall at the Amargosa pupfish refugium in Ash Meadows.
<br />In 1991, high counts were 80 fish in October, due to a pump failure, but returned to 104 in April 1992. This last figure
<br />is within the range of past years of stable counts.
<br />Currently, the Hoover Dam pupfish refugium contains less than 5 fish. Ten fish were placed in the refugium in
<br />December of 1991, and to this date no reproduction has taken place.
<br />2. Pahrump killifish, Empetrichthys latos latos - Census work was conducted on the three populations of Pahrump
<br />killifish at Corn Creek, Spring Mountain Ranch State Park, and Shoshone Ponds Refugium. All populations are stable
<br />or increasing. The combined population estimate of killifish at the three sites is approximately 24,000 fish. Population
<br />estimates are 9,084 and 13,546 at Corn Creek and Spring Mountain Ranch. At Shoshone ponds 1600 fish were trapped
<br />over a 3 hour period. At the Corn Creek refugium, dense growth of Typhus sp. in the three ponds had completely
<br />eliminated open water areas. Fish and Wildlife personnel continue to treat the cattails with spray applications of Rodeo
<br />herbicide, which are proving to be very successful.
<br />3. Hiko White River springfish, Crenichthys baileyi grandis - Populations were monitored at Hiko, Crystal, and
<br />Blue Link Springs. The Hiko and Blue Link populations are stable or expanding. Mark and recapture estimates showed
<br />6,000 fish in Blue Link Spring and 7,450 in Hiko Spring. The springfish at Crystal Spring remain at a severely depressed
<br />level due primarily to the numbers of exotic fish present in the spring source pools and outflows. The current population
<br />is estimated at 20-30 fish. Methodology needs to be developed to control numbers of exotics at this site to effect a
<br />recovery of the springfish population.
<br />4. White River springfish, Crenichthys baileyi baileyi - Census work at Ash Spring indicates that the White River
<br />springfish population had a marked improvement in 1991/92 but continues to be depressed due, to the presence of exotic
<br />species and disturbance by public use. Restricted use over a large portion of the pool has returned it to a natural state
<br />because annual drainings have not occurred. This has allowed the springfish to better compete with exotic cichlids and
<br />mollies. The larger portion of this spring is currently for sale, and efforts are being made to acquire this property. The
<br />spring source and head pool are on public land and recent improvements by the BLM have been effective in eliminating
<br />livestock use from the area. Numbers of springfish were estimated to be 7,452 at Ash Spring.
<br />The outflow from Ash Spring, listed as critical habitat for both the springfish and the Pahranagat roundtail chub
<br />Gila robusta jordani, is located on private lands. Estimates of Pahranagat roundtail were made by establishing dive
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