Tidal Series: Tidal Energy – Pro-testing, not Protesting

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I am a Nova Scotian – a proud graduate of Acadia University (BScHon, MSc) and a professor in Acadia’s Biology Department since 2005. My perspective on the harvesting of Bay of Fundy tidal energy using stand-alone turbines (not housed within a barrage as in the Annapolis River) has been developing since 2006. At that time, the province of Nova Scotia was actively seeking opportunities to further reduce the burning of fossil fuels, considering the potential of the Bay of Fundy’s world class tidal energy resource to contribute to the mix of local sources of renewable energy.

As in Scotland, the province began to investigate this potential by initiating the establishment of an in-stream (barrage free), tidal turbine test centre. The selected test area is located in the northern region of the Minas Passage, near the town of Parrsboro. This test facility, known as the Fundy Ocean Research Centre for Energy (FORCE), is a not-for-profit organization largely funded by the federal and provincial governments and is Canada’s leading test centre for tidal energy research and development. Its purpose is to test the performance of large, commercially-ready, stand-alone devices that are cabled to the shore and connected to the province’s electrical grid. The first cable-connected turbine is expected to be installed in late 2015.

FORCE’s objectives include assessments of the environmental effects on, and of, installed turbines. Success or failure will inform decisions on the possible role (if any) of tidal energy in Nova Scotia’s energy future. To fulfill the government’s interest in representation from the environmental science community, I was invited by the province to be an independent director on the Board of FORCE when it was first established in 2009. I also conduct research that is related to the activities of FORCE.

Development of any marine industry poses potential risk to the environment and tidal energy is certainly no exception. Two strategic environmental assessments and a series of workshops and public information events have focused on the potential consequences of tidal energy development in the Bay of Fundy. Not surprisingly, the highest priority ecological components of concern are migratory fish and marine mammals. But how does one assess risk of turbine interaction with marine life in a very high flow, macro-tidal environment? I can tell you that it very challenging and that it requires a lot of funding, a lot of collaboration, and innovative, technological approaches. Monitoring the effects requires several years of baseline data on the environmental conditions and ecology of the site prior to the installation of turbines.

Some of the environmental questions raised have been: How is the FORCE test area and Minas Passage being used by migratory fish species of concern, including lobsters and marine mammals? When are they present? At what depth do swimming animals transit through the passage? For the past 6 years, Acadia students (Honours, MSc), faculty and colleagues elsewhere have been trying to answer these questions with the aid of modern, acoustic technologies. Some of these technologies have been used to track the movements of fish (Striped Bass, Atlantic Sturgeon, Atlantic Salmon, and American Eel) that were implanted with transmitters (emitting identifiable ping sequences). We have also used hydrophones to detect and record the seasonal presence and activity of harbour porpoises in the Minas Passage. Their presence is heard when they vocalize for the purposes of communication, navigation and feeding. Porpoises emit a series of high frequency echolocation clicks; bats use a similar echolocation system.

Perhaps the most difficult question we are asking, and which requires a turbine to be installed, is this: Can fish and marine mammals detect and avoid large infrastructure when moving through the passage at high speed? The answer to this question is likely to vary among species, and with both size of animal and season. Although critical, little is known about this topic largely because there have been very few stand-alone tidal turbine installations around the globe. The efficiency of some of the acoustic technologies used to detect animals is also reduced in naturally “noisy” high flow tidal environments.

Regardless, attempts are being made to collect environmental effects data. The next turbine installed at FORCE will be fitted with both imaging and listening sensors to detect animals and their behaviour in close proximity to the device. I believe that we cannot learn much (if anything) about the impacts of in-stream tidal turbines in the Bay of Fundy if we do not install and test one or more turbine technologies at FORCE. This test centre presents an exciting learning opportunity for Nova Scotia, and for Acadia faculty and students, and what we are learning with this test facility has implications for tidal energy developments worldwide.

Dr. Anna Redden

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