9615

• UCREFRP Catalog Number: 9615
• Author: Miller, W. J., D. E. Rees and J. A. Ptacek.
• Title: Draft Summary of 2001 Tasks Fryingpan/Roaring Fork Rivers Fishery Study.
• USFW Year: 2001.
• USFW - Doc Type: Fort Collins, CO.
• Copyright Material: NO

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The results provided by macroinvertebrate sampling efforts and accurate identifications
can provide a great deal of valuable information pertaining to the flow regime and other
aquatic conditions.
Sampling was conducted during spring and fall of 2001. Four sites were sampled in the
spring and five sites in the fall. At each location three samples were taken in riffle
habitat. All samples at a given site location were taken in areas of similar size substrate
to avoid bias that may be directly related to substrate size. Because of its effectiveness at
various flows, a Hess Sampler was used during sampling to provide quantitative
invertebrate data. Macroinvertebrates were preserved in ethanol and transported to the lab
where they were sorted, enumerated and identified to the lowest practical taxonomic level
(Merritt and Cummins 1984; Ward and Kondratieff 1992). The "lowest practical taxonomic
level" means that all specimens will be identified down to the level that is permitted by the
available physical characteristics. Early life stages of many species sometimes lack certain
anatomical characteristics that allow the specimen to be identified to the genus or species
level. In these cases the "lowest practical taxonomic level" may mean only the family level.
In instances where proper identification is possible, the Orders Ephemeroptera, Plecoptera,
and Trichoptera were identified to genus (and many down to species). Most specimens of
other Orders, including Diptera, were identified to the genus level, however, members of the
family Chironomidae were only identified to subfamily or tribe. Further identification
would require mounting of head capsules - an expensive and time-consuming process. As a
means of QA/QC, Dr. Boris Kondratieff (Professor of Entomology at Colorado State
University) confirmed identifications in all cases where the identification of a species is
difficult or questionable. Population densities and species lists were developed for each
sampling site. Data collected will be used in various indices recommended by the Rapid
Bioassessment Protocols (Plafkin et al. 1989) to provide information regarding
macroinvertebrate community structure, function, and general aquatic conditions.
Indices used include Shannon-Weaver diversity and evenness, Family Biotic Index, EPT
index, and description of functional feeding groups. Shannon-Weaver diversity and
evenness values will be used to detect changes in macroinvertebrate community structure.
Draft 2001 Task Summary Report Page 16
Miller Ecological Consultants, Inc. December 18, 2001