Dames & Moore, 1999 - USDA Forest Service

The invertebrate sampling was performed using a kick net of 500 micron mesh. The work
performed by Dames & Moore used an enclosed sampler with 250 micron mesh netting
and is considered a preferred sampling procedure. The invertebrates collected by Ecology
did not represent the full range of invertebrates collected by Dames & Moore and
demonstrates a lack of disturbance of the substrate when collecting.
The taxa list, metals tolerance list, and mean number of organisms provided in the Ecology
report show a nearly complete lack of invertebrate organisms at and downstream of the
Site. The Dames & Moore data demonstrate a very different picture with a change in
community structure and reduction in numbers.
The invertebrates found by Dames & Moore at and downstream of the Site are among the
most metal intolerant organisms found on the list provided by Ecology. It is not likely that
the community changed significantly between 1996 (Ecology sampling) and 1997 (Dames
& Moore sampling) but the difference is more likely a result of the collection methods
employed in the two studies.
4.6.1.4 Fish Communities '
Ecology found the sediment not toxic and the toxicity of water was uncertain.
Fish communities within Railroad Creek consist of primarily cutthroat (Oncorhynchus clarki spp.) and
rainbow trout (0. miss). Mottled sculpin (Cottus bairdt] have also been observed within Railroad Creek
(PNL, 1992). Numerous fish barriers located within the canyon relief of reach B preclude the upstream
movement of fish originating in lower Railroad Creek or Lake Chelan. Occasionally, Kokanee (0. nerh
nerh) will enter the creek from Lake Chelan iri late September or early October in search of spawning
areas. During the fall (1997) investigations, approximately 10 Kokanee salmon were observed in lower
Railroad Creek. Although a comprehensive spawning survey was not included in the 1997 investigations,
opportunistic observations were made of the stream substrate conditions during a reconnaissance of
Railroad Creek in early September and during the subsequent benthic macroinvertebrate ad fish
sampling. Upon observing Kokanee in the lower segment of Railroad Creek (within approximately 300
yards of Lake Chelan), a more thorough reconnaissance of substrate conditions was conducted within that
segment of Railroad Creek in an attempt to identify the existence of gravel suitable for spawning.
Considering female salmon usually dig redds in a riffle area in small- to medium-size gravel (Wydoski
and Whitney, 1979), the results of the reconnaissance indicated that very little, if any, substrate suitable
for spawning existed within this segment of Railroad Creek.
Fish communities were sampled by snorkeling at all ten locations while electrofishing was utilized at all
locations excluding South Fork Agnes Creek and Company Creek. The results of the snorkeling and
electrofishing sampling are presented in Table 4.6-3. A summary of the general composition and condition
of the fish at each location electrofished is presented in Table 4.6-3a.
As indicated during past fisheries studies of Railroad Creek (PNL, 1992), cutthroat trout were the most
abundant trout collected throughout all locations while rainbows and rainbowlcutthroat hybrids were
occasionally collected. Cutthroat trout were present at all ten sampling locations. Rainbow trout were
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17693-005-019Vuly 19. 1999;4:5 1 PM:DRAFT FINAL RI REPORT