YCT Multi-state Assessment February 10, 2003 



rated as high or good. Secondly, for those segments where no quantitative fish abundance data 

 were available, YCT abundance was ranked solely from the condition of habitat relative to its 

 potential. Data quality for these cases was rated as low. Thus, when quantitative fish abundance 

 information was available both the measured abundance and habitat condition were used to rank 

 relative abundance. When no quantitative abundance data were available only habitat condition 

 was used to rank abundance. These results were also summarized by length of habitat occupied 

 and not by number of stream segments occupied. Number of stream segments was not felt to be 

 a meaningful measure because this number does not equate to number of populations and lengths 

 of stream segments varied widely. Where field data were available, abundance was rated based 

 on how similar the measured abundance was to measured abundances from areas of similar types 

 of habitat that were not impacted by human activities. Where no field data were available, 

 abundance classes were subjective and based, to a large extent, on the quality of the habitats 

 occupied. Consequently, analyses between the relative abundance levels we assigned and land- 

 use or other habitat-related variables were not independent. 



Table 2. Codes and descriptions used for 

 assessing relative abundance of 

 Yellowstone cutthroat trout in 2001 . 



Code Description 



99 Unknown 



A Abundant - viewed as being at site 

 potential or in high quality habitat 



C Common - Possibly slightly below site 

 potential or habitat less than opfimal 



R Rare - Restricted by sub-optimal habitat 

 or significantly below site potential 



Designated "Conservation Populations" 



YCT are considered a game fish by all state and federal agencies that manage this subspecies. 

 Consequently, all YCT populations have sport fish value and are managed as such by the various 

 states and national parks in which they occur, regardless of their genetic status. Many YCT are 

 managed as "conservation populafions" with addifional management emphasis placed on 

 preserving the genetic makeup and/or other important attributes of these populations. Most of 

 the western states that have management and conservation authority for cutthroat trout 

 participated in the development of a posifion paper on genetic management (Anon 2000). This 

 position paper describes a hierarchical classification for conserving cutthroat trout that includes: 

 1) a core component of genetically unaltered populafions or individuals; 2) designated 

 conservafion populations that may be either genetically unaltered or slightly introgressed but 

 have attributes worthy of conservation; and 3) populations that are managed primarily for their 

 recreational fishery value. Core populations are recognized as having important genetic value 

 and would serve as donor sources for developing either captive brood or for re-founding 



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