ALP 3

Contents
Brown trout (Salmo trutla), rainbow trout (Oncorhynchus mykiss), and Snake River cutthroat
trout (O. clarki) are introduced regularly as game fish. Channel catfish (Ictalurus punctatus),
largemouth bass (Micropterus salmoides), and green sunfish (L. cyanellus) have been
sporadically released for many years as game fish but are found primarily in the San Juan River
below the Farmington Lake Diversion (nearest downstream passage barrier from Animas River
confluence). Fathead minnow (Pimephales promelas) and mosquitofish (Gambusia afnis) are
more common throughout the San Juan River Basin and the white sucker has established
populations in various tributaries and occurs as small concentratitts in the Animas River. Black
bullhead (I. melas) and common carp (Cyprinus carpio) constitute` slightly more than 1 percent
of the total fish sampled (Valdez 2008).
The bluehead and flannelmouth suckers are likely a desitable prey " item for some nonnative
piscivores where they occur together. Large nonnative predators occur" many of the drainages
that contain bluehead and flannelmouth suckers: 'Wiese include brown trout rainbow trout,
channel catfish, and smallmouth bass (M dolor u)_ (Ptacek et al. 2005). predation on native
suckers has been documented in the San Juan River ih;New M and in the iatapa and Green
Rivers within Colorado (Brooks et al, 2000, Rupport et" i(J. 1993). In the Animas bluer between
the city of Durango, CO. and the cotlfluen,W with the San'"3uan River in New Mexico there are
eight nonnative predator fish species. "They ttactude; brown tip t (14.32 percent), rainbow trout
(13.72 percent), cutthroat x rainbow hybrid trout (p,4t ">percent),`hake River cutthroat trout (6.59
percent), black bullhead (fl,A "percent), largemouth bassf0.20 per66* green sunfish (0.03
percent), and two ehatme1 catfish "individuals that werd"also captured out of a total of 43,038 fish
sampled over a ten"year,period (Valdez 2008).""
Lake Nighthorse is in the trnmediate' cinity of the city of Durango, CO. where it is easily
accessible tt, anglers. The Animas River „' passes from north to south through the town and is a
well known recreational area'for fly fishing and river rafting. As a result of outdoor recreational
opportunities a town's hiric features, tourism has become the cornerstone to the local
economy and Lake N%lithorse t=vill further augment local commerce. Lake Nighthorse has been
stocked with nonnative game,,Ash during 2010 and 2011. The Colorado Parks and Wildlife
(CPW) released 50,000 aduk rainbow trout into the reservoir during the fall of 2010 and another
50,000 adult rainbow trout in the fall of 2011. Also, approximately 75,000 juvenile kokanee
salmon (O. nerka) were stocked by CPW in April 2011. Fathead minnow and crayfish
(Orconectes spp.) were present in Basin Creek before the reservoir filled. Since the reservoir
filled CPW has also documented; mottled sculpin (Cottus bairdi), Johnny dater (Etheostoma
nigrum), white, bluehead, and flannelmouth suckers in the reservoir, these fish species are also
found in the Animas River (Jim White, CPW, personal communication, 2012).
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