Document Type

Thesis

Degree Name

Master of Science (MSc)

Department

Biology

Program Name/Specialization

Integrative Biology

Faculty/School

Faculty of Science

First Advisor

Michael Wilkie

Advisor Role

Supervisor

Abstract

Sea lamprey (Petromyzon marinus) are jawless fishes that invaded the Laurentian Great Lakes in the early 20th century. Predation of fishes by blood-feeding juvenile sea lamprey contributed to major declines in populations of native fish species including economically and culturally important species of lake trout and whitefishes. Sea lamprey continue to threaten fisheries and biodiversity in the Great Lakes, making it necessary to control their populations using chemical control methods that target larval sea lamprey, and the use of barriers and dams to prevent adults from spawning. While current control methods effectively target mainly the larval and adult life-stages, juvenile sea lamprey are much more elusive and difficult to control. More effective control of sea lamprey during their juvenile life stage will require greater knowledge of their movements and behaviour during their downstream migration following metamorphosis, and their movements in the near-shore areas after they enter the Great Lakes. Biotelemetry tags could be used to track juvenile sea lamprey, but their small and elongated body plan makes it difficult using typical radio-tags or acoustic technology, without impeding their anguilliform swimming. The eel/lamprey acoustic tag (ELAT) is a miniaturized acoustic tag suitable for the body plan of small, elongated fishes, that has the potential to provide insights into the behaviour and migratory patterns of juvenile sea lamprey. However, it is important to ensure that ELAT implantation does not cause physiological and behavioural changes that would cause inaccurate representations of wild populations.

The physiological effects of surgery and ELAT implantation in fasted juvenile sea lamprey were investigated for 30 days following tagging. Surgery and ELAT implantation in did not cause any reductions in gross energy content, based on stable carcass protein content and lipid concentrations. Nor were there any differences in the concentrations of glycogen, ATP or PCr in the muscle, and liver glycogen reserves were similarly unaffected.  Collectively, these findings suggests that the basal energetic costs of carrying the ELAT were minimal. Additionally, there was no evidence that the implantation of the ELAT resulted in chronic stress to the animals since no differences were observed in plasma 11-deoxycortisol and glucose. In conclusion, ELAT implantation did not impact the metabolic capacity and stress response in juvenile sea lamprey, which suggests ELAT implantation is a suitable method for tracking this life-stage during their downstream migration and in nearshore areas prior to the onset of feeding. Improved understanding of juvenile sea lamprey behaviour and movements using the ELAT could inform novel strategies for their control at the most destructive stage of their life history in the Great Lakes.  ELAT tagging could also benefit efforts to conserve native species of sea lamprey in their native range along the Atlantic coasts of North America and Europe, where many populations are imperiled.

Convocation Year

2027

Convocation Season

Spring

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Available for download on Monday, March 29, 2027

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