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• Section 779.20 (c) Continued. relatively abundant and comprised 21.3 percent of the total mean density or 16 organisms/ft2. Although no damsel fly naiads were collected, several adults were noted flying in the immediate area of the stream. No sample collections were made at this station during the 1975 baseline study. Appreciable flow was present at the middle Foidel Creek Station, but the channel remained narrow (about one foot wide), steep sided, and choked with filamentous green algae and, in places, American eel grass (Vallisneria americana). The bottom was well shaded b}- streambank vegetation, largely sedges and grasses, and consisted largely of medium to fire gravel in the riffle areas and sandy silt in the pool areas. Aereal ext~nt of riffle habitat was greater than the extent of pool habitat. Lower Foidel Creek. Results of aquatic macroinvertebrates collected • from lower Foidel Creek. are presented in Table 66, Density, Percent Relative Abundance, Diversity and Equitability of Aquatic Macro- invertebrates Collected From Lower Foidel Creek. Surber samples were dominated by blackfly larvae which comprised 39.6 percent of the total mean density or 10.5 organisms/f t2. Unidentified Orthocladiini midge larvae were the next most 2bundant taxon repre- senting 34.0 percent or 9 organtsms/ft2. Naidid worms (Oligochaeta: Naididae) comprised 9]4 percent total relative abundance while tubificid worms accounted for 3.8 percent. In the Ekman grab samples tubificid worms were by far the most abundant group and comprised 63.0 percent of the total mean density or 17 organisms/ft2. Chironomid midge larvae were the second most abundant group and represented 22.2 percent of tl:e total mean density nr 5 organisms/ft2. The midge Procladius sp., a predator, was the most abundant (7.4 percent relative abundance) chironomid species. Unidentified mayflies (Ephemeroptera) comprised 11.1 • percent of the mean total relative abundance of 3 organisms/ft2. 779-228