YCT Multi-state Assessment February 1 0, 2003 



Table 2. Look-up table for type of source information used. 



This protocol is segregated into three primary components for conducting this assessment. First, 

 the historical range that was occupied by YCT at the time of the first European exploration of the 

 Northern Rocky Mountains will be estimated. Second, the current distribution, abundance and 

 genetic status information for YCT will be displayed. Lastly conservation populations, either as 

 isolated and meta-populations (networked or connected populations - e.g. interbreeding 

 populations), will be identified and population viability risk and genetic risk assessments will be 

 made for each of these populations. Risk will be assessed at two levels: 1) risk of genetic 

 introgression, and 2) population level risk. Risk assessments represent relative determinations 

 indicating a higher or lower level of concern. The mapping and risk assessments will be 

 completed for all populations including those associated with lakes that are maintained by 

 natural reproduction. Populations supported or augmented by stocking will not be included. 

 Definitions of terms used for this protocol are provided in italics as they are first used. 



Population mapping unit (segment) - each stream, or occupied segment of stream, will be 

 treated as a separate population (stock) mapping unit or segment and connectivity 

 between these segments will determine whether these segments function in terms of an 

 isolate population or as a "metapopulation ". 



Conservation Populations - those cutthroat populations existing in a geneticallv unaltered 

 condition (core consen'ation population with genetic analysis indicating greater than 99% 

 purity^) and/or populations having unique ecological, genetic and behavioral attribute of 

 significance that maybe genetically introgressed (See Cutthroat Trout Management: A Position 

 Paper - Genetic Considerations Associated with Cutthroat Trout Management). Conservation 

 populations may exist as isolates or networks of subpopulations. 



M eta-population- infers that interbreeding between subpopulations (population mapping 



segments) can occur within a generation (3-5 years). Also referred to as a connected or 

 networked population. 



Isolated Population - Some populations occupy isolated habitat fragments (isolates) and these 

 populations likely operate independently from connected groups of subpopulations. 



Genetic Risk - risk of initial or on-going genetic introgression (hybridization). 



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