Evaluation of Techniques for the Marking of Mummichogs with Emphasis on Visible Implant Elastomer

Abstract

AbstractWe conducted two experiments to determine the most appropriate method for use in a mark–recapture study of movements of the mummichog Fundulus heteroclitus in the southern Gulf of St. Lawrence. In the first experiment, 315 mummichogs were marked with fin clips, fingerling tags, acrylic paint, or visible implant elastomer (VIE) and were held for 144 d. Percent tag retention (98.5%) and survival (100%) were highest for the VIE group, and no negative effect was observed on length growth. This led to a more detailed experiment (167 d) to assess potential negative effects of VIE on the growth and survival of 144 mummichogs marked on various body locations; we also assessed mark retention and readability in this experiment. No negative effects on growth were detected; mean daily length increases ranged from 0.04 to 0.12 mm, and specific growth rates for all groups ranged from 0.129% to 0.470%. Mean survival of all groups was 90.8% (range = 66.7–100%) and was higher in marked groups than controls. All marks were retained and visible without the aid of a light‐emitting diode light at the end of the experiment, thus demonstrating that VIE is a suitable method for the marking of mummichogs.