Recovery of Marked Fish in Cove Rotenone Samples

The use of fin-clips and dart tags for detennining recovery efficiency in summer cove rotenone samples was compared. Using a standardized cove sampling methodology, fin-clipped fish were recovered from 69 coves at an overall rate (%) of 52.4 ± 4.7 (2 S. E.), while in 21 coves 73.6 ± 3.0% of the dart-tagged fish were recovered. As the sample season progressed recovery efficiencies for fin-clipped fish showed a consistent improvement, however, neither seasonal nor year-to-year means was as high as dart-tagged estimates. End of season values with both marking methods showed a recovery efficiency of about 70 percent in the reservoirs surveyed.