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Fish Populations Increase in Baker and Lehman Creeks
by Rob Colvin

During August 2003 fish populations were surveyed in Baker and Lehman Creeks with volunteer assistance from the Southern Nevada Chapter of Trout Unlimited (SNCTU). The surveys used backpack electrofishing equipment to perform three pass surveys. For each stream, a 100m section was blocked off with nets, and staff attempted to remove all the fish from that section by stunning them with an electrical current and netting them. Fish were then identified, measured, weighed, and returned to the stream at the end of the survey. The number of fish found in each 100m section were extrapolated to estimate the number of fish per mile.

Baker Creek
The 1990 survey electrofished 500ft with one pass between the Grey Cliff Narrows and Baker Creek trailhead, and estimated 598 brown trout, 367 brook trout and 123 rainbow trout per mile. The 2003 survey took place approximately 50m upstream of Baker Creek Campground. Fish per mile estimates were 692 for brown trout, 756 for brook trout, 531 for rainbow trout and 547 for young of the year (YOY). Average length for all trout species was approximately six inches. Fish per mile totals in the 2003 survey were slightly higher for BNT and much higher for BKT and RBT. Although the methods varied between the two surveys, an increase in the population reveals Baker Creek has suitable spawning, feeding, and rearing habitat and can provide ample opportunities for recreational anglers.

Lehman Creek
A population survey conducted in 1990 on Lehman Creek between the park boundary and Lehman Creek Campground using one pass electrofishing projected 15 brown trout, 243 brook trout and 516 rainbow trout per mile. A 2002 survey at the same location predicted 106 brown trout, 275 brook trout, 381 rainbow trout and 42 YOY per mile, using the three-pass method. In 2003 a 100m section was surveyed at the Lower Lehman Creek Campground, with estimates of 209 brown trout, 627 brook trout, 595 rainbow trout and 466 YOY per mile. Brown trout lengths averaged seven and a half inches (190mm), with rainbow trout at six inches (162mm) and brook trout at five inches (137 mm). All trout species and YOY populations showed large increases in population size from 1990 to 2003.

Summary
Comparing the 2003 fish population surveys, more fish were caught in Baker Creek, with 157, than in Lehman Creek, with 118. The proportion of each species caught for each creek was similar, except for brown trout, which were found in more abundance in Baker Creek. This is possibly due to a lower-elevation survey site in Baker Creek, and larger pools and riffles in the 100m section. The 2003 fish population surveys showed larger overall population sizes than previous surveys.

Acknowledgements
A special thanks goes to the members of SNCTU for volunteering over 400 hours of their time to help with various fisheries projects during the 2003 field season.

Reference
GRBA/NDOW Trout Survey Field Trip Reports, 1988-1991.

Rob Colvin was the lead fisheries biological science technician during the 2003 field season.