Biological Monitoring
The use of a biological entity (taxon, species, assemblage) as a detector and its response to change as a measure of response in determining environmental conditions. Ambient biological surveys and toxicity tests are common biological monitoring methods; also known as "biomonitoring".
Channel Metric
A metric of the cQHEI and QHEI that assesses the features and condition (e.g., natural vs. channelized channels) of stream channels that provide habitat important to aquatic life.
Existing Use
A use that was actually attained in a waterbody on or after November 28, 1975, whether or not they are included in the state water quality standards (November 28, 1975 is the date on which U.S. EPA promulgated its first water quality standards regulation in 40CFR Part 131). Existing uses must be maintained and cannot be removed.