Measures of the Health of Rivers and Streams - Hydro-Environmental Analysis: Freshwater Environments - page 195

TABLE 7.1
Examples of Criteria for Selection of Reference Conditions for a Rapid Bioassessment

Example Criteria for Reference Sites (Must Meet all Criteria)
• pH ≥ 6; if blackwater stream, then pH ≤ 6 and DOC >8 mg L -1
• Acid neutralizing capacity ≥50 μeq L -1
• Dissolved oxygen ≥4 ppm
• Nitrate ≤300 μeq L -1
• Urban land use ≤20% of catchment area
• Forest land use ≥25% of catchment area
• Instream habitat rating optimal or suboptimal
• Riparian buffer width ≥15 m
• No channelization
• No point source discharges

Source: USEPA. Watershed Academy Web: Rapid Bioassessment Protocols, USEPA Distance learning modules on
Watershed Management at www.epa.gov/waetrtrain (last accessed 11 August 2013), n.d.

TABLE 7.2
Metrics from Survey Approach for Compilation of Historical Data

Limiting Factor Probable Cause

Insuficient instream structure Agriculture

Insuficient cover Silviculture

Insuficient sinuosity Mining

Loss of riparian vegetation Grazing

Bank failure Dam

Excessive siltation Diversion

Insuficient organic detritus Channelization

Insuficient woody debris for organic detritus Urban encroachment

Frequent scouring lows Snagging

Insuficient hard surfaces Other channel modiications

Embeddedness Urbanization/impervious surfaces

Insuficient light penetration Land use changes

Toxicity Bank failure

High water temperature Point source discharges

Altered low Riparian disturbances

Overharvest Clear cutting

Underharvest Mining runoff

Fish stocking Stormwater

Nonnative species Fishermen

Migration barrier Aquarists

Other (specify)
Not limiting

Source: Barbour, M.T., Gerritsen, J., Snyder, B.D., and Stribling, J.B., Rapid Bioassessment

Protocols for Use in Streams and Wadeable Rivers: Periphyton, Benthic
Macroinvertebrates and Fish , U.S. Environmental Protection Agency, Ofice of
Water, Washington, DC, 1999.