Effects of passive integrated transponder tag size and implantation site on age-0 walleye and muskellunge tag retention, growth and survival

Fisheries management requires an understanding of the processes regulating populations, including recruitment, growth, mortality, emigration, and immigration. Tagging provides one of the best methods for addressing these questions, and PIT tags represent one of the newest technologies. Passive integrated transponder tags generally have high retention rates and minimal effects on fish growth and survival. Multiple PIT tag sizes are available, but little is known regarding the effects of tag size on tag retention, growth, or survival in fish. Thus, our objectives were to evaluate the effects of three PIT tag sizes (12, 23, and 32 mm) and two implantation sites (dorsal muscle and body cavity) on tag retention, growth, and survival of age‐0 walleyes (Sander vitreus) and muskellunge (Esox masquinongy) . Fish (210 individuals per species per year) were randomly assigned to one of six treatments or a control during 2014 and 2015 and were held for 112 d. Walleye survival was lower in 2014 (87%) than in 2015 (>99%) but did not vary between implantation sites or among tag sizes; muskellunge survival was 100% during both years. Tag retention over 112 d was nearly 100% in walleyes regardless of tagging site or tag size. In muskellunge, tag retention was lower during 2014 (65%) than during 2015 (93%) and was lower when implanted in the body cavity (63%) than in the dorsal muscle (87%); however, tag retention was similar among tag sizes. Walleyes and muskellunge grew little over the winter, and growth was generally similar among fish with different implantation sites and tag sizes. Collectively, our results indicate that PIT tags larger than 12 mm can be successfully used in walleyes and muskellunge and will likely increase the tag detection rates for these species, particularly in studies that use stationary PIT tag antennas.