Artificial Marker Selection and Subsequent Tagging Evaluations with Juvenile Burbot

Abstract

AbstractA conservation program developed by regional stakeholders incorporates stock enhancement as one of several approaches to restore an imperiled Burbot Lota lota population native to Idaho and British Columbia. Tagging juvenile fish is pivotal to stock enhancement monitoring; however, limited information is currently available on marks or tags applied to Burbot. We identified six criteria to guide artificial marker selection that are specific to imperiled juvenile fish. A short‐term experiment with age‐0 Burbot (65–92 mm TL) tested fin clips, freeze brands, visible implant elastomer, passive integrated transponders, and an unmarked control group. At 4 weeks posttagging, no significant differences were found between marking treatments with respect to fish survival (100%), absolute growth rate (0.15 ± 0.06 mm/d), specific growth rate (0.55 ± 0.32 g·g−1·d−1), or condition factor (0.64 ± 0.05). Mean tag retention ranged from 88% to 100%, and no significant differences were detected between treatments. Recognition of dorsal freeze brands differed significantly between two independent tag assessments. Overall, we found no adverse short‐term effects and high tag retention in this preliminary trial of seven artificial marks applied to hatchery‐reared Burbot.