WCT Multi-state Assessment 



February 10, 2003 



Table 1 

 Rankj 



Look-up table for significant diseases risk ranking. 



Risk Characterization 



Significant diseases and the pathogens that cause these diseases have very limited 

 opportunity to interact with existing WCT population. Significant disease and 

 ipathogens are not known to exist stream or watershed associated with WCT population. 

 Barrier provides complete blockage to upstream fish movement. Stocking of fish from 

 other sources does not occur. 



Significant diseases and/or pathogens have been introduced and/or identified in same 

 stream and/or drainage further than 10 km from WCT population, but not in same 

 stream segment as WCT, or within 10 km where existing barriers exist, but may be at 

 risk of failure. Stocking offish from others source areas requires fish health screening 

 and pathogen free clearance. 



Significant diseases and/or pathogens have been introduced and/or have been identified in 

 same stream and/or drainage within 10 km of WCT population and no barriers exist 



between disease and/or pathogens and diseased fish species and the WCT population. 

 However, diseases and/or pathogens have not yet been found in same stream segment as 

 WCT population. 



Significant disease and/or pathogens and disease carrying species are sympatric with 

 WCT in same stream segment but WCT have not tested positive. 



WCT population is known to be positive for significant disease and/or pathogens are 

 present. WCT population has a history of impacts from significant diseases. 

 Environmental and/or biological conditions may have intensified disease impact. 



Conservation Population Risk Assessment 



Population risk assessments will be done for each meta- or isolate population using a ranking that includes 

 consideration of four factors. Risks will be ranked from low to high by using a 1 to 4 ranking system based on 

 four variables identified by Rieman et al. (1993) (Table 12). These four main factors will be weighted to derive 

 a final risk factor as follows: Temporal Variability = 0.7; Population Size = 1.2; Population Productivity 

 (Growth/Survival) = 1.6; and Isolation = 0.5. Take into consideration those actions and activities (Tables 13 and 

 14) that may have an influence on population risk. The level of risk should not be viewed as an absolute but 

 rather as a indicator of possible or potential risk. 



For each conservation population it is important to identify those conservation actions, past or ongoing, that 

 have been intended to protect, conserve and enhance the specific conservation population (Table 13). Each 

 watershed folder will contain summary fornis that will allow for adding quantitative information associated with 

 the conservation actions taken. It is also important to identify those land-uses (Table 14) that are or maybe 

 exerting negative impacts to the conservation population and/or the associated habitat. The information on 

 conservation actions and land-use influences can be important as genetic and population risks are assessed. For 

 land use activities level of significance is important. Identify only those activities that have either a known 

 (has been documented) or a possible influence on total population integrity (viability). DO NOT 

 IDKNTIFY ACTIMTIES THAT ONLY HA\ E AN INFLUENCE ON A MINOR NUMBER OF 

 INDIVIDUALS WITH IN A POPULATION. 



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