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5.0 Benthic Macro-organism Studies <br />• 5 •1 Methods <br />ks part of the biological sampling prc¢•am benthlc organisms were sampled <br />three times during the 1976-77 period; October 1976, March 1977 and July 1977. <br />The same four sampling stations were used or. the North Fork as were used for <br />wale-- quality studies. No samples were taken in Stevens Gulch because of its <br />intermittent nature. <br />Organisms were sampled xith a Ness-type bottom sampler constructed <br />out of a 55 gallon drum. Thls device sampled a large effective stream <br />bottom area (2.85 ft.` 0.26 N,ZJ and was very useful in surrounding the <br />large cobbl6 of the stream bed. The sampler was placed so that the outer <br />teeth encompassed completely most of the cobblesxithin its circumference. <br />kith two people, the sampler was then worked down into the substrate ~+-6 inches <br />• from the top o° the cobbles. Stores that we^e mainly inside the circumference <br />were included in the simple and stones that were mainly outside'of the cir- <br />cumference were excluded from the sample. <br />Fach of the large= stones was then individually picked up and all sides <br />vigorous'-y xas!ied and rubbed to remove organisms. The sma'_ler gravel and <br />sand was disturbed and swirled around to a depth of approximately 3-4 inches <br />below the cobbles. Org`zisms and debris were collected in a fine-mesh bag* <br />downstream of the dist+.L~bed area,& samples were then transferred to labelled <br />0 <br />jars containing 70 ethyl alcohol. <br />Laboratory procedures involved staining of the sample with a 1:1 mix- <br />tu=e o'_' i~.osin b and 3ietrich scarlet at a concentration of 1:500 in 5~ <br />farmalin (Williams, 1974), picking out the stained organisms from <br />• * mesh fine enough to capture small chironomids <br />5-1 <br />