7891

• UCREFRP Catalog Number: 7891
• Author: Vinson, M.
• Title: A Sampling Strategy For Assessing Aquatic Invertebrate Communities Associated With Endangered Fish Populations In The Upper Colorado River Basin.
• USFW Year: 1996.
• USFW - Doc Type: \
• Copyright Material: NO

different sampling dates using strategies one or two.

Disadvantage: Like the previous strategy,.this strategy does not allow for the detennination

of the variability among similar habitats within the same reach. Another

disadvantage of this strategy is that it assumes a representative location of

each habitat exists and that it was selected.

Recommendation: I recommend carrying out strategy one on the initial sampling trip and

strategy two on subsequent trips. Strategy one will give us an understanding

of the variability in invertebrate communities among similar habitat types

within the same reach and allow to calculate appropriate sample sizes for

each habitat type. Use of strategy two after this initial trip will save money

and still provide substantial information on the variability in invertebrate

assemblages among habitats and among reaches over time.

Thus, during the initial sampling trip a subset of sampling locations of each habitat type within
each reach would be sampled. All samples collected from the same habitat type within the same
reach would be kept separate. This procedure would be repeated for each habitat type present in
each reach. Within lengthy reaches sampling sites should be selected such that samples are
collected from upper, mid, and lower sections of each reach. On subsequent trips, samples from
like habitats within the same strata would be coinbined. The same locations need not be sampled
on subsequent sampling trips. A summary of the number of samples to be collected is shown in
Table 3.

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