Water Shrew 



123 



were quantified over a 100-m stretch following the general methodology of 

 Platts et al. (1983). Values for in-channel parameters are reported as the mean of 

 measurements made at 5- or 10-m intervals along the entire 100-m stretch. Com- 

 position of the riparian vegetation was made from surveys of canopy trees along 

 both banks. All habitat analyses were conducted in a three-day period in June 

 1995 when streams were at base flow. 



The second approach to characterizing stream and riparian habitat was 

 a formal assessment using the U.S. Environmental Protection Agency's (EPA) 

 Rapid Habitat Assessment Protocol (Plafkin et al. 1989). Twelve metrics were 

 used to score habitat condition at each stream (Table 2). All metrics were scored 

 on a 20-point scale, 20 points indicting the best or preferred condition. A portion 

 of the riparian zone and near-channel watershed of one of the sites at which S. 

 palustris was collected was timbered between the time that the shrews were col- 

 lected and the habitat analysis was conducted. Habitat data from this site were 

 not included in our summary. 



Table 2. Parameters measured for the habitat assessment of streams where S. 

 palustris was found in Virgina. Methodology follows that of Plafkin et al. (1989). 



Parameter 



General Description 



In-stream cover 

 Epifaunal substrate 



Embeddedness 



Velocity /depth ranges 



Channel alteration 

 Sediment deposition 

 Frequency of riffles 

 Channel flow status 



Condition of banks 

 Bank vegetative cover 



Disturbance pressure 



Riparian vegetation 



abundance of submerged logs, undercut 



banks, and other forms of stable habitat 



abundance of the "most productive 



benthic habitat," typically riffle areas 



and/or submerged snags 



degree to which the primary substrate 



was surrounded by fine sediment 



variety of water velocity and depth 



regimes in the stream 



evidence of stream channelization 



evidence of recent sediment deposition 



prevalence and size of riffles 



percentage of the channel bed that was 



wetted 



evidence of bank stability versus erosion 



percentage of bank that was covered with 



vegetation 



degree of disruption of riparian vegetation 



by grazing or other processes 



width of riparian zone that was vegetated 



and with minimal human disturbance 



