Lake Ontario Deepwater Cisco
Project Title
Post-stocking behaviour, distribution and survival of deepwater cisco in eastern Lake Ontario
Project Code
Project Duration
November 2015 - December 2020
Project Description
The LODWC project ran from 2015 through 2020. Annual or twice-annual stocking events between 2015 and 2018 saw acoustically tagged bloater (Coregonus hoyi) released with large numbers (15,000 to 32,000) of untagged bloater during normal stocking procedures. In total, 364 bloater carrying a mix of V6, V9, V9-P, V9-PT, and V9-D transmitters were released in either spring or fall. The project specific receiver array consisted of a network of 80 acoustic receivers encircling a deep-water channel to measure their post-release behaviour, dispersal, habitat use, and survival. At it’s peak, the LODWC array included 144 kHz receivers. In 2017, extensive physical, chemical and biological data in and around our array were assimilated from partners to inform behaviour and survival analyses. In 2019 receivers in the core of the St Lawrence channel were thinned to ~50% density (based on a redundancy analysis informed by range testing). The "liberated" receivers were used to complete the "Duck-Galloo" double line running continuously (~2.5 km offset spacing) from the Ontario to NY coastlines. In 2020, the original LODWC array was decommissioned as the bloater post-stocking assessment project was completed. Receivers were re-deployed in Lake Ontario, conforming to a 7.5 km square grid while still retaining the "Duck-Galloo" double line to enhance our understanding of multi-species interbasin movement through corridors. In 2021, a small 9 receiver array was established off Cobourg, in central Lake Ontario, to assess post-stocking movement and survival of 3 age-classes of bloater released during the daytime and at night. This work evaluated hypotheses related to behaviour and physiologic responses seen in our previous work. GLFC funding awarded in 2021 will investigate compression barotrauma in bloater and other deepwater cultured fishes, as this mechanism was determined to be a significant source of mortality for cultured bloater. Predation, possibly accentuated by the barotrauma, was also a significant source of mortality. In 2022, the Duck-Galloo double line was decommissioned, with receivers again being re-deployed elsewhere in Lake Ontario
Participating Organizations