PARENT SESSION
Poster Session #23: Fish, Lakes, Streams, and Wetlands.
Wednesday, August 8, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall
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Assessing the relationship between habitat and fish communities in determining stream water quality.
PERRY, JAMES1, WOODWARD, JOSHUA1, PREVOST, LUANNA2, 1 2
ABSTRACT- The Blue Earth, Le Sueur and Lower Minnesota watersheds together generate more than 60% of the phosphorus, nitrates and suspended sediment in the Minnesota River Basin. To implement effective water resource management, stream water quality can be assessed on different spatial scales. Two measures were employed to assess stream water quality in three watersheds in south central Minnesota. The measures, Index of Biological Integrity (IBI) and habitat rating, were based on fish communities and stream physical features, respectively. We studied 31 sites in two agroecoregions, rolling moraine and wetter silts and clays. Each site was sampled by electrofishing, followed by a habitat assessment which includes measures or visual estimations of fish cover, riparian buffer, and stream substrate and depth. Statistical analysis revealed no correlation between IBI and habitat scores. However, these scores are qualitative and direct comparison may prove difficult. Although there was some relation among the components of either score, distinct patterns were not observed between components of the two scores. The uniformity of the surrounding agricultural land may impact stream water quality more than local habitat.
KEY WORDS: water quality, stream assessment, Index of Biological Integrity