A note from Peter Unmack, Arizona-Nevada NANFA Regional Representative
March 19-22, 1998, saw a successful conservation trip to the southeastern portion of
Nevada. Members from several conservation orientated clubs participated in this event
including the Bay Area Killifish Association, North American Native Fishes Association,
Northern California Killifish Club, and Tropical FishKeepers Exchange. A great fun filled
weekend was had by all. Our first effort was concentrated on the Moapa River near
Glendale. Tilapia (Oreochromis aureus) had recently invaded parts of the upper
springhead near the Fish and Wildlife Service Refuge. Great gobs of tilapia were found
throughout the spring outflow along with a good numbers of mollies (Poecilia mexicana)
and damnbusia (Gambusia affinis). A few native springfish (Crenichthys
baileyi moapae) and Moapa dace (Moapa coriacea) were also seen but they were
far rarer than the section without tilapia. Further downstream near the old powerstation
diversion dam fish were virtually non existent. Electrofishing revealed virtually no fish
except a couple of exotics. Gill nets were set overnight in the ponds down at the power
plant. Last year Jim Heinrich (Nevada Division of Wildlife) caught good numbers of Virgin
River chubs (Gila seminuda) here. The only fishes caught by us were more
great gobs of tilapia (some up to 16 inches) and a few baby mollies were observed. The
Moapa is indeed a pretty sick system at this point in time.
Our second destination was the Virgin River at Mesquite. Both woundfin (Plagopterus
argentissimus) and Virgin River chubs have been released here from hatchery stocks
here. The fish have small metal tags which allow them to be distinguished from wild fish.
Good numbers of most native fish were found including speckled dace (Rhinichthys osculus),
flannelmouth sucker (Catostomus latipinnis), and desert sucker (Pantosteus
clarki) as well as the two stocked natives. Red shiners (Cyprinella lutrensis)
were present, but in lower numbers than usual. While the riverine environment looked to be
in really healthy shape it doesn't last very long. According to Jim Heinrich, water
diversions during summer virtually dry this stretch of river leaving the fish little
suitable habitat and elevated water temperatures. We moved upstream into Arizona to the
mouth of Beaver Dam Wash primarily to collect desert suckers for genetic work by Carol
Secor, a graduate student at Arizona State University. Fortunately good numbers of suckers
were found along with hundreds of speckled dace! That evening saw us camp further upstream
in Beaver Dam Wash at a delightful campground. Here we were finally able to see some
Virgin River spinedace (Lepidomeda mollispinis), the rarest native fish in this
drainage.
All in all a great time was had by all participants. I'd like to thank all those who made
the effort to come along and help. Special thanks go to Ellen Siegal who did a fantastic
job feeding the group. Also, thanks again to Jim Heinrich for allowing us the opportunity
to get involved and for making arrangements. All collecting in Nevada was done under his
supervision, collecting in Arizona was conducted under state and federal permits.
Best Fishes
Peter J Unmack
peter.unmack@asu.edu