8055 ‎(2)‎

• UCREFRP Catalog Number: 8055
• Author: Crowl, T. A. and N. W. Bouwes.
• Title: A Population Model for Four Endangered Colorado River Fishes - Final Report.
• USFW Year: 1998.
• USFW - Doc Type: Logan, Utah.
• Copyright Material: NO

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collection as part of the Upper Basin Recovery Program; 5) use the mfldels and the
parameter estimates obtained from the data synthesis step to determine the current
status for all identifiable subpopulations of the endangered fish; and 6) make the
models available to state and federal managers to perform simulations of management
scenarios and predict possible outcomes.
A tremendous amount of effort and money go into the upper basin annually with the
intention of recovering the endangered fish species. This model should guide those
efforts in terms of providing a tool for determining which data are needed to first
understand the current status of the populations, make some assumptions about the
causes of those patterns and finally to be able to document any changes in population
trends associated with management or even environmental changes. Currently, there
seems to be a number of `sampling' procedures and protocols that provide data in
search of a question. The questions are hard, but seem straight forward: i) What are
the current population trends of the target populations; 2) Why do they look the way the
do; 3) What can be done to change those patterns if so desired and 4) What
information is needed to document any responses that may occur. A modeling
approach such as the one employed here can help in organizing and directing activities
specifically aimed at the first question of determining the population status and trends
currently and the last question of determining how future changes can be documented.
A generic model was developed (initially using Mathcad and later translated to Quattro-
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