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

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The tributary system of the Big Thompson River was sampled at 140 locations (Table 23).
Eighty-six of those locations were dry, and an additional 26 wet sites contained no fish.
Approximately half of the 28 locations where fish were found were within the Little Thompson
River drainage. Sampling efficiency was good throughout the drainage with the exceptions of
several of the Little Thompson sites where irrigation returns kept the water turbid throughout the
sampling period.

Fathead minnow, longnose dace, and creek chub dominated the tributary collection,
comprising 81 percent of the catch. Johnny darter and white sucker provided an additional 14
percent. The remaining 4 percent of the sample consisted mostly of sand shiner, carp, brown
trout and rainbow trout (Table 24). Longnose sucker, central stoneroller, green sunfish, plains
topminnow, yellow perch, and pumpkinseed sunfish were found in trace numbers. Approximately
8 percent of the fish sampled were uncommon or environmentally-sensitive species. Introduced
species accounted for 2 percent of the collections.

The most notable difference between the mainstem results and the tributary fish
populations is the virtual absence of central stoneroller in the tributaries. This species is sensitive
to water quality degradation and excessive siltation. The stoneroller was the most abundant fish
taken in mainstem sampling (Table 22). The number of species found per site was generally lower
throughout the tributaries compared to mainstem sites.

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