Table 4-6. Summary of procedures to obtain measurement data and indicator values at each sampling site. 



Field Procedures: 



Standard sampling gears and techniques: 



"Best Effort" sampling using a combination of gear types, standardized sampling times and 

 distances (40 times mean channel width (Lyons 1992) or 150 m, whichever is greater). 



• Electrofishing 



• Seining 



Identify individual fish to species and enumerate. 



Documented Protocols: 



Lazorchak et al. (1998): EMAP Surface Waters-Streams Methods Manual 

 Similar protocols used by other large-scale monitoring programs. 



• Meador ef al. (1993): National Water Quality Assessment Program (NAWQA) 



Laboratory Procedures: 



Confirm species identifications from voucher specimens. 



Compile autecological information for each species from published sources of life history data. 

 Obtain information regarding assemblage composition and structure under conditions of minimal 

 human disturbance. 



Data Analysis Procedures: 



Standard approaches for multimetric-based indicators (Karr et al. 1986, Plafkin ef al. 1989, 

 Klemm ef al. 1993, Barbour ef al. 1995, Simon and Lyons 1995). 



Compute response values for each metric (e.g., species richness, proportion of tolerant individuals) 

 based on abundance data and autecological information for each fish species. 



Determine expected conditions for each metric response. 



• Metrics based on numbers of species require calibration for stream size. 



Develop "maximum species richness lines" (Fausch ef al. 1984) 



Data from all sites used, rather than just "reference sites" (Simon and Lyons 1995). 



• Metrics based on proportion of individuals require expectations based on composition 

 of a fish assemblage under conditions of minimal human disturbance. 



Expectations modified when possible, based on knowledge of historical assemblages 

 prior to European settlement (Hughes 1995). 



Compute scores for each metric based on deviation of response from expectations. 



• to 10 scale: Differs from standard approach (1,3, 5): Provides more continuous 

 distribution of scores (Hughes ef al. 1998). 



Sum metric scores to produce indicator value. 



• Rescale to be between and 100: differs from standard approach (no rescaling) 



Use EMAP techniques (e.g., Diaz-Ramos et al. 1995) to calculate distribution of indicator values in 

 estimated resource populations based on probability sample. 



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