Implantation with a novel micro-acoustic tag impairs aerobic metabolism of postmetamorphic sea lamprey

One of the challenges in managing the invasion of sea lamprey in the Laurentian Great Lakes is understanding the early behaviour of parasitic juveniles. The eel-and-lamprey acoustic tag (ELAT; 12mm × 2mm, 0.08g in air; akin to a 12mm PIT tag), may finally open the possibility of tracking this poorly understood life-stage. Understanding if the ELAT alters the physiology and behaviour of the tagged animals is essential prior to wide application in the field. We implanted migrating juvenile sea lamprey (4.95±0.41g) of wild and lab-reared origin with a mock ELAT and used intermittent-flow respirometry to quantify resting and maximum metabolic rates of control, sham surgery, and tagged groups. We found that ELAT implantation led to a 14% reduction in the maximum oxygen consumption capacity and a respective 15% reduction in aerobic scope of juvenile sea lamprey over untagged controls, and also that juvenile sea lamprey of lab-origin had lower aerobic metabolic capacity than their wild counterparts. These physiological effects could translate to behaviour alterations after tagging and release, influencing management decisions if not accounted for.