| |
Presented at the NABS Annual meeting, Pittsburgh, Pennsylvania, 2002
in Bioassessment
DEVELOPMENT OF A HABITAT ASSESSMENT PROTOCOL FOR MICHIGAN’S LARGE RIVERS – DIFFERENTIATING IMPACTED FROM NON-IMPACTED RIVER SEGMENTS.
J.G.O. Wilhelm1, J.D. Allan1, K.J. Wessell2, R.W. Merritt2, and K.W. Cummins3. 1School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109-1115 USA, 2Department of Entomology, Michigan State University, East Lansing, MI 48824 USA, 3California Cooperative Fisheries Unit, Department of Fisheries, Humboldt State University, Arcata, CA 95521 USA
Stream assessment protocols to evaluate the ecological integrity of streams and describe trends over time based on water quality, biota, and habitat quality are widely available for small rivers. However, the development of large river assessment protocols is in its infancy. By modifying small-steam habitat methods, we assessed habitat at reach, riparian, and landscape scales on ten non-wadeable rivers in Michigan’s lower peninsula during 2000 and 2001. Habitat measures were validated against landscape characteristics and macroinvertebrate biotic integrity. We selected the Manistee as representative of unimpacted rivers, and the Grand as a more highly impacted river, to determine which habitat variables might be important in distinguishing impacted from non-impacted reaches. Two sites on the Manistee received high scores for riparian composition, quantity of large woody debris, and fish cover composition compared to four sites on the Grand. The two Manistee sites scored higher than three of the four Grand sites for the visual metric of human disturbance. These four measurements emerged as variables which most effectively differentiate site quality and which will likely influence the composition and distribution of stream biota.
|
|
