Information available on the near-field effects of tidal in-stream energy conversion (TISEC) devices on marine mammals is sparse. And data on diel activity patterns of marine mammals in the upper Bay of Fundy is lacking. The main questions addressed by this collaborative project between Acadia University and SMRU Ltd, in relation to TISEC device testing, are:
- What are the activity levels of key cetaceans, specifically porpoises and dolphins, in the Minas Passage turbine demonstration area during late summer/fall?
- How does porpoise and dolphin presence/activity near the deployed NSPI (OpenHydro) turbine compare with presence/activity at a control site?
The study involved a continuous ~3 month long passive acoustic marine mammal monitoring field study (10 August 2010 – 23 November 2010) while the NSPI (OpenHydro) tidal turbine device was deployed in the Minas Passage. Three C-POD hydrophones (autonomous cetacean echolocation click detectors, Chelonia Ltd) were deployed and recovered using custom-fitted bottom moorings with acoustic releases. Two devices were positioned in close proximity ~150m east and west of the turbine, while a third ‘control’ device was positioned ~700m west of the turbine site. Two C-PODs (east of the turbine and the control site) recorded click data continuously until the batteries expired (89 and 92 days post-deployment). The remaining C-POD only collected one day of data before stopping and its mooring sub-buoy was recovered damaged. Recommendations for deployment improvements, data loss prevention and future study design are made.