Field study to compare the use of three types of artificial substrata for the quantitative sampling of benthic macroinvertebrates in lotic habitats with a coarse substratum. Two modifications to the procedures of using artificial substrata were evaluated experimentally by examining macroinvertebrate colonization on artificial substrata, with or without a natural benthic cover of fine sediment and algae, and on artificial substrata that were either embedded or placed on the natural substratum. Macroinvertebrates of the natural substratum were also sampled to compare these organisms with the fauna of the artificial substrata.