Trends in methods for assessing freshwater habitats

Habitat assessment is an important form of management for species conservat ion, mitigation planning, environmental regulation, and impact assessment. As part of an American Fisheries Society and U.S. Fish and Wildlife Service project, we surveyed state, provincial, federal, and private organizations to obtain documentation about methods being used to assess,aquatic habitat s in the inland waters;of North America. We then used this information to c haracterize attributes of established methods. We found that most methods t arget habitats;associated with flowing waters, but a significant number of methods deal exclusively with lakes and reservoirs. The survey showed that the dominant purpose for having an established method was to standardize me asurements and data collection techniques. Methods for stream habitats incl uded a wide array of measurements emphasizing channel structure, water move ment, substrate, cover, and riparian zones. The lentic habitat methods emph asized the littoral zone, hallow-water physical structure, and riparian are as. Data. analyses were primarily numerical summaries and calculations of d escriptive;statistics usually presented using databases, Assessment methods focused on aquatic environmental quality-more so than fishery resource eva luations-although methods associated with fishery investigations remain pro minent. The overall characteristics of currently used methods suggest that many dr most: agencies are actively advancing their practices, and rapid ch ange can be expected in most methods.