8032

• UCREFRP Catalog Number: 8032
• Author: Desert Fishes Council.
• Title: Proceedings of the Desert Fishes Council Volume XI - The Eleventh Annual Symposium.
• USFW Year: 1979.
• USFW - Doc Type: E. P. Pister, ed. November 15-17, 1979.
• Copyright Material: NO

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Rogers: The spring pool itself contains under 150 fish (probably due to
its size), but the outflow has several hundred pupfish in the area before the
irrigation diversion. Gambusia is also very abundant in the outflow and is
the most abundant fish in these waters. The whole system supports upward of
500 fish, and probably a much higher estimate can be expected if the adjacent
marsh lands are considered.
Cyprinodon nevadensis pectoralis: Warm Springs pupfish
Population estimates were also carried out for this subspecies in May
of 1979 except for School Springs. The fish population in this spring was
censused on December 20, 1979• Each habitat is treated in order of occurrence
in Table 1.
Indian: The pupfish population in this spring is rather small and
reflects the small amount of available habitat. This system maintains a
population of approximately 250 pupfish mostly confined to the outflow in
and adjacent to the wooded area below the spring.
Marsh: The pool habitat below the spring has an excellent population
of pupfish of all size classes. Both young of the year and fry were observed
in this area as well as in the outflow below the dike. The total estimate
for this system probably exceeds 3000.
School: The main pool system at this spring has over 300 fish at the
present time, and the small observation pool in the lower enclosure has over
100. The emergent vegetation continues to proliferate through these springs,
and control measures are scheduled for this April. This will include a
coordinated study to assess various techniques of vegetation control and
subsequent response of the pupfish population.
Scruggs 1,2: The large pool habitat below the outflow of the spring head
contains several hundred pupfish, and reproduction has occurred as young-of-
the-year and many fry were observed. The immediate outflow below the pool
habitat also contained good numbers of pupfish, and the system collectively
supports approximately 2000 fish.
Rhinichthys osculus nevadensis: Ash Meadows speckled dace
The dace population at Springdale and Beatty continues to survive in the
intermittent portions of the Amargosa River, although they fluctuate widely.
Current taxonomic studies on these and other Death Valley system dace are
continuing to determine subspecific status. The populations present in Ash
Meadows were treated under the springs listed for C.n. mionectes and C.n.
pectoralis. The total population of dace in the Ash Meadows area cannot
exceed 3000. The two highest populations are at Jackrabbit and Big Spring.
Jackrabbit is the only system where the dace is not heavily impacted by
exotic fishes. The intermittent nature of the Springdale and Beatty
populations, in conjunction with the reduced numbers in the Ash Meadows area,
warrant that this fish be listed as threatened or endangered. Continued
development in the area will no doubt continue to impact this species.