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<br />Assessment and <br />Applied Research <br /> <br />The presentations by biologists involved in developing or using stream assessment methods reflect the <br />challenges and tradeoffs of simplifying complex systems for use in practical but valid methods. The speakers <br />of this group vary considerably in their approaches, although all are primarily interested in stream fishes. <br />One group of speakers emphasizes the need to develop and use methods based on measures of fish com- <br />munities and natural flow regimes. These biologists believe that assessment methods need to use infor- <br />mation on all fishes rather than a few target species, and they address patterns of streamflow rather <br />than simply minimum flow. Other speakers emphasize the practical aspects of stream assessment and <br />the usefulness of assessment methods based on easily estimated and narrowly focused measures. These <br />biologists deal with stream system complexity and practical constraints by advocating the use of methods <br />that vary from simple statistical standards (e.g., median August flow, percent of mean annual flow) to <br />computer modeling. Ironically, when the management outcomes of different assessment methods were <br />compared (see Orth and Leonard), the differences were not that striking. The solution to appropriately <br />simplifying the complexities of stream communities seems to be far away but may emerge from the choice <br />of methods made by management biologists as they face future stream impact issues. <br /> <br />~ <br /> <br />~ <br /> <br />25 <br />