Until the mid-1950’s, a diverse assemblage of deepwater ciscoes including Bloater (Coregonus hoyi) inhabited Lake Ontario. Currently, only the shallow-water form of Cisco (C. artedi) remains. The Lake Ontario Committee of the GLFC has established a plan to reestablish a self-sustaining deepwater cisco population within 25 years. The work is supported by the Lake Ontario Fish Community Objectives and guided by the Joint Management Strategies for the Reestablishment of Native Deepwater Ciscoes in Lake Ontario. As part of this initiative, fertilized Lake Michigan Bloater eggs have been collected by the US Fish and Wildlife Service, raised to juvenile stages (10-19 months post-hatch) in New York and Ontario, and stocked in small numbers (16-20 thousand/year). With improvements to wild egg collections and significant progress in brood stock development, the planned target to stock 500 thousand juveniles/year may soon be possible. At present, we do not know what will happen to the stocked fish after introduction. Do hatchery fish survive in the wild and does survival change through time? Do they quickly disperse or stay close to their stocking site? Do they school closely together and move as group? Acoustic telemetry, which monitors the movement of tagged fish using receivers, has the potential to provide this information and improve the efficacy and success of the Bloater restoration project and native species restoration efforts across the Great Lakes. Through controlled hatchery studies, we have established that Bloater recover and survive well (96% through 6 months, n=150) following surgical implantation of a range a acoustic telemetry transmitters (i.e., tags). The next step is to establish if we can track hatchery reared, acoustically tagged Bloaters upon release in the wild (i.e., Lake Ontario). This project seeks to addess this question by releasing a small number (50) of tagged juvenile Bloater within a larger stocking of ~5,000 fish in early November, into a 60 receiver array that will be established in the St Lawrence Channel (40-60m deep) in eastern Lake Ontario. A current GLFC funded project is quantifying the detection range of 180 kHz telemetry equipment needed for smaller juvenile fish. The proposed array will monitor the movement and behaviour of the stocked fish for up to 1 year. Receivers will be downloaded one (December) and seven (June) months after release of the fish to provide initial data and potential to reposition the array. The methodology (surgical techniques, deepwater large scale acoustic arrays) will pave the way for development of comparative stocking and culture initiatives (other life-stages, seasons, locations, culture conditions) to inform and improve Bloater restoration outcomes and could potentially be applied to other species and issues in the Great Lakes.
CAN ACOUSTIC TELEMETRY TRACK POST-STOCKING BEHAVIOUR OF BLOATER IN LAKE ONTARIO?