8063 - Laserfiche WebLink

Home Browse Search

Annual report Colorado River Fish and Wildlife Council Colorado River Cutthroat Trout Conservation April 21, 1998 The second task remaining to be accomplished is the evaluation of these populations for acceptable levels of "viability" or "probability of persistence". Colorado and Wyoming have approached the issue using adult size and population abundance criteria similar to that adopted for the greenback cutthroat trout recovery program. Utah has favored population size criteria for other fish species based on extrapolation of "effective population size". At issue is which is the best way to define healthy population status and how should small headwater stream populations with relatively small numbers of adult fish fit into conservation goals. This remains a significant issue that could be difficult to reconcile among the participants, but it is also a key to providing credibility to the strategic plan. The Biology and Coordination Committees are scheduled to meet May 5, 1998 to discuss the draft lists of conservation and restoration populations and to initiate the consensus-building process. Discussion will likely continue to center on questions of how the various kinds of information related to genetic purity should be used in developing the baseline. A range of opinion exists about use of various types of background data for designation of purity levels and about the use of "less-than-pure" populations in conservation planning. Although a technical definition of viability will probably not be a part of the baseline development process, questions are also expected about appropriate designation for populations that are extremely small or otherwise have a a very low probability of persistance. Depending on final resolution of an acceptable level of purity for conservation purposes, the draft population data suggests 35-61 existing CRN populations may be included in the baseline for Colorado across 10 geographic management units and 37-66 populations for Wyoming across five geographic management units. Based on greenback criteria, "viable" populations occupy up to 90 stream miles and 350 lake acres in Colorado and 90 stream miles and 99 lake acres in Wyoming. Due to the relevance of the issues of acceptable genetic purity and population viability to FWS considerations for listing, and the implications of the outcome of this tri-state strategic planning process to establishing the range-wide status of CRN, a suggestion has been made that an Fish and Wildlife Service representative with decision-making authority for the agency over the tri-state area be assigned to the Coordination Committee to provide administrative continuity. There has also been feedback concerning a need for caution in committing the group to an unreasonable timeline. This is especially an issue if the inter-agency part of the objective-setting process for each GMU is to be accomplished in more than a cursory fashion. When consensus has been reach among the participants concerning an acceptable baseline of pure populations and their role in 4 1 u J U