WSP04463

• File Number: 8460.500
• Description: Platte River Recovery Plan
• Basin: South Platte
• Date: 6/1/1997
• Author: Colo Div of Wildlife
• Title: Inventory and Status of South Platte River Native Fishes in Colorado
• Water Supply Pro - Doc Type: Publication

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

trout, longnose sucker, central stoneroller, and sand shiner, collectively, made up 13.5 percent of
the catch. Black crappie, carp, bluegill, brassy minnow, Iowa darter, johnny darter, rainbow trout
and plains topminnow were found in trace numbers.

Introduced species, primarily brown trout and largemouth bass totaled 6.1 percent of the
fish sampled in this segment, which was considered relatively high. However, the trout came
from the uppennost sites on Left Hand Creek, which are colder environments favored by trout.
The largemouth bass found were young-of-the-year that likely escaped from adjacent ponds aod
gravel pits, and probably pose little threat to native species populations. Several ponds were
sampled in this area as opposed to most of the other hydrounits, aod 472 of the 484 green sunfish
sampled came from these lentic environments.

While the tributaries of the St. Vrain River do not share much similarity with the mainstem
with respect to species richness, the potential for native species maoagement in this drainage is
very high. If the limiting factors which have prevented colonization of Boulder, Left Haod, Coal,
and Dry creeks, and possibly others, by rare or sensitive species can be identified and mitigated,
these tributaries may provide valuable habitat for these species. Transplaoted fish in tributary
populations could enhance stability as "buffer" populations to the St. Vrain, aod possibly create a
meta-population structure. While the St. Vrain River appears healthy from a fish diversity and
rare species presence, water quality was poor at several of the sampling sites, and continued water
quality degradation or another serious pollution event on the mainstem could have disastrous
consequences.

These findings are relatively unchanged from the 1980s. Propst (1982) had a site on Left .
Hand Creek, and several sites on Boulder Creek near our study area. Chart et al. (1986) had
three sites on Left Hand Creek, and one on Boulder Creek which are comparable to our locations.
The same abundant species we found were abundant in both Chart and Propst's collections.
Johnny darter, plains killifish and sand shiner had decreased in numbers collected from Propst's
sampling, both in Chart et al. (1986) aod this inventory. Chart reported finding over 50 each of
bigmouth shiner and gizzard shad at single locations. These species were not taken in the Propst
or 1994 inventories in this drainage.

33