Skip to main content
U.S. flag

An official website of the United States government

Prerelease stratification in tag-recovery models with time dependence

January 1, 1993

A statistical model is developed for estimating time-dependent survival and recovery rates of tagged populations that are stratified into groups at release. For populations of fish, the groups might include different sexes or stocks, or they might be distinguished by the location or method of capture. In the model developed here, survival and recovery rates are formulated as linear combinations of parameters that include the effects of time, group, and time–group interactions. Methods of testing the statistical significance of these potential sources of variation are described and illustrated with the recoveries of different stocks of anadromous striped bass (Morone saxatilis). For the striped bass data, elimination of time- and stock-specific sources of variation substantially improved the precision of survival estimates without introducing important bias. During 1988–89 the average survival of both stocks was 0.78 (SE = 0.04). Calculations of statistical power indicate that stock-specific differences in survival of ± 0.2 could have been detected about 50% of the time, given the low rates of recovery and numbers of fish released.

 

Publication Year 1993
Title Prerelease stratification in tag-recovery models with time dependence
DOI 10.1139/f93-062
Authors R.M. Dorazio
Publication Type Article
Publication Subtype Journal Article
Series Title Canadian Journal of Fisheries and Aquatic Sciences
Index ID 1008472
Record Source USGS Publications Warehouse