Tidal Energy Development in the Bay of Fundy - Pro-testing, not Protesting
The Bay of Fundy is renowned for the highest tides in the world (17m in range) and equally impressive current speeds — up to 6 meters per second in the Minas Passage. The Bay is ecologically rich, with diverse and abundant migratory species, and has been recognized as exceptionally productive and sensitive, inspiring two UNESCO World Heritage Site designations.
Numerous high flow sites in the Bay of Fundy have been identified as suitable for tidal energy development. The responsible harvesting of energy from these sites requires examination of the power potential, the environmental effects of harvesting tidal energy, and the associated socio-economic benefits and impacts on communities, fishers, and other users.
My perspective on the harvesting of Bay of Fundy tidal energy using stand-alone turbines (not housed within a barrage or dam as in the Annapolis River, Nova Scotia) 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 and was 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, Bay of Fundy, 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 center for tidal energy research and development. Its purpose is to test the performance of large, commercially-ready, stand-alone devices that are cabled to shore and connected to the province's electrical grid. In-stream turbine testing at the FORCE site will serve to inform decisions made on the role (if any) of tidal energy in Nova Scotia's energy future. FORCE also has a stewardship role, with an active environmental monitoring and research program, and engagement with the general public largely via the FORCE Visitor Centre.
The first test to demonstrate tidal turbine installation and recovery at FORCE took place in 2009-2010. Since then, subsea electrical cables have been installed on the seafloor. Two cable-connected OpenHydro turbines are expected to be deployed at FORCE in late 2016, followed by other device types as shown below.
Figure 1. Location of the FORCE test site in the Minas Passage, Bay of Fundy. The picture on the right shows the towing of the OpenHydro turbine and barge before turbine installation on the seafloor in late 2009.
Figure 2. FORCE Visitor Centre overlooking the Minas Passage and FORCE test site (red arrow).
Figure 3. Proposed in-stream tidal energy turbines for testing at FORCE, commencing with Cape Sharp Tidal's new OpenHydro design (bottom right).
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 identified potential consequences of tidal energy development in the Bay of Fundy. Not surprisingly, the highest priority biological 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 was very challenging and that it requires much funding, much collaboration, and innovative, technological approaches.
Monitoring environmental effects require several years of baseline data on the environmental conditions and ecology of the site before the installation of turbines. Some of the environmental questions we have been addressing include: How is the FORCE test area and Minas Passage being used by migratory fish (focused on species of concern), lobsters and marine mammals? When are they present? At what depth do swimming animals transit through the passage? For the past seven years, Acadia faculty and students, 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 that emit identifiable signals (ping sequences). We have also used hydrophones to detect and record the seasonal presence and activity of harbor porpoises in Minas Passage. Their presence is heard when they vocalize for communication, navigation, and feeding. Porpoises emit a series of unique 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 massive infrastructure when moving at high speed through the FORCE test area? The answer to this question is likely to vary among species and with both sizes 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 of the challenges and technical limitations, attempts are being made to collect environmental effects monitoring data. The next turbine installed at FORCE (late 2016) will be fitted with both imaging and listening sensors to detect animals and their behavior near the device. It is clear that we will not learn much (if anything) about the impacts of in-stream tidal turbines in the Bay of Fundy if we do not install, test and observe the environmental interactions of a range of turbine technologies at FORCE. This test center presents an exciting learning opportunity for Nova Scotia and the Gulf of Maine bioregion, and what we are learning with this test facility has implications for tidal energy initiatives in the Bay of Fundy-Gulf of Maine system and elsewhere in the world.
We have a responsibility to future generations to be pro-testing (versus protesting) all available renewable energy options. And when there are success and commercial development proceeds, we must ensure that development happens responsibly and sustainably. My advice to all readers is this… stay informed, communicate and educate, and be an active steward of your region!
Anna Redden is a Marine Biology Professor at Acadia University in Nova Scotia. She is also the Director of the Acadia Centre for Estuarine Research, which is primarily focused on the estuaries and nearshore coastal waters of the Bay of Fundy. Anna is the co-founder and Director of the Acadia Tidal Energy Institute and also serves as the Chair of the Fundy Energy Research Network. During the last decade, Dr. Redden has led some tidal energy environmental projects at the Fundy Ocean Research Center for Energy (FORCE) test site in Minas Passage. Anna’s research activities with collaborators and students have involved understanding how marine animals utilize high flow environments. This includes tracking the movements of coastal fishes and lobsters, assessing marine mammal activity patterns and investigating sediment-animal relationships in the Minas Passage. She has been involved with the delivery of GOMI stewardship programs for many years, and currently, provides support for the L2SG teacher's program in Nova Scotia.