9559

• UCREFRP Catalog Number: 9559
• Author: Martinez, A. M.
• Title: An Evaluation of Nonnative Fish Control Treatments in Ponds along the Colorado and Gunnison Rivers, 1996-2002.
• USFW Year: 2004.
• USFW - Doc Type: 18/19,
• Copyright Material: NO

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entitled to an access fee for both sampling and NNFC, but only accepted the fee for
sampling.
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Cost Estimate to Control Nonnative Fish
CDOW developed a matrix in 1997 (Martinez 1997) to estimate the cost of NNFC
projects within the study area based on an inventory of ponds provided by Mitchell
(1995). The original cost estimate matrix included 321 ponds of which 308 ponds were
identified by Mitchell and another 13 were added by CDOW. The 321 ponds accounted
for approximately 846 SA and 7,396 acre-feet. Pond ownership and position in the
floodplain were also documented. However, it was later determined numerous ponds
were not included in the original matrix. Among these were 141 ponds in the river
corridors examined by Mitchell (1995), and 92 ponds between Rifle and Cameo (which
were absent from the Mitchell report due to the unavailability of aerial photographs).
More-recent estimates of the cost to control 551 ponds comprising 1,416 surface acres
(449 along the Colorado River and 102 along the Gunnison River) are summarized in
Table 6. While Table 6 includes ponds inadvertently omitted in the Mitchell (1995)
report, newly-constructed ponds, and ponds documented in the original matrix, it does
not include ephemeral ponds that were taken over by the river since the Mitchell report,
ponds that are void of fish, or ponds known to contain only native fish. Similarly, ponds
owned by landowners that declined to participate in the NNFC program were not
included in the Table 6 cost estimate. Application of rotenone/KMn04 was the least
expensive treatment scenario ($2,418,996) to control fish in all 551 riverside ponds,
while the most costly scenario involved chlorine application preceded by pumping in an
area where three-phase electricity was not available ($6,534,556) (Table 6). These cost
estimates are based on chemical, supplies and labor in 1997 dollars, and therefore
most likely underestimate future costs to control nonnative fish.
Field Sampling and Nonnative Fish Control Activities
Fish Sampling --- Of the 329 ponds that were investigated, 191 ponds contained
fish. Of these 191 ponds, 147 ponds contained only nonnative fish, one pond contained
only native fish, and 43 ponds contained both native and nonnative fish. Overall,
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