Periphyton samples were collected concurrently with macroinvertebrate samples at the 11 sites according to a modified method described in Porter and others (1993). A device called an SG-92, which is constructed from part of a syringe body, a toothbrush, and a rubber O-ring, was used to scrub the attached periphyton from a rock surface and allow that solution of water and algae to be collected in a hand pipette for transfer to a wide-mouth plastic jar. The device has an area of 3.66 cm2, which is used in density calculations. Five rocks were collected at each of the five cross sections, and the SG-92 was used on five separate spots on each rock at streamside. The cumulative sample area then was 458 cm2 for the composited periphyton sample. Formalin was added to each composite sample to equal 3 to 5 percent of the total sample volume for preservation.

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