Lydia Paulic

Glider Pilot

RAEON

paulic@uwindsor.ca

Stocking of hatchery-raised fish is a common practice to enhance wild populations, restore extirpated species, and introduce novel species for management or recreation. Extirpated in the 1980s, bloater (Coregonus hoyi), a deep-water coregonid native to Lake Ontario, are currently the focus of a bi-national restoration effort (2012-present) with the overall goal of re-establishing a self-sustaining population in Lake Ontario to restore fauna to resemble the historic offshore prey fish community that in turn, may improve recruitment of ecologically and economically important species (e.g., Lake Trout). Current stocking occurs over deeper water to reduce predation effects and link to preferred habitat, but recent acoustic telemetry research has quantified significant mortality due to predation and potentially barotrauma.To address this, my MSc research focused on tagging hatchery-reared juvenile bloater (relevant stocking-sizes (~11-30 g)) with high resolution acoustic predation tags and were released over three bathymetric depths (5, 50, and 100 m) in southeastern Lake Ontario to quantify survival, movement, and to assess potential sources of mortality associated with depth of release or predation, or both. Addressing these objectives expands on our fundamental knowledge of bloater ecology and provides insight into the immediate post-stocking movements of a reintroduced forage fish, and will contribute to the refinement of stocking methods for other deep-water species in the Great Lakes.

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During my MSc research, we also utilized Teledyne Marine's Slocum glider, a type of autonomous underwater vehicle, and Innovasea's VR2C cabled acoustic receivers, to track tagged fish in near real-time across an expanded study area using relatively little resources. In addition to fish tracking, the gliders also collect important environmental information about the surrounding habitat of the species of interest. Following completion of my MSc, I have stepped into the role as RAEON's glider pilot.