Abstract
Tidal stream energy has the potential to become a significant contributor to clean energy targets and an important response to climate change. Canada is now witnessing a new wave of tidal energy activity in the Bay of Fundy, by companies such as Sustainable Marine, BigMoon Power, and Nova Innovation. But uncertainty around potential impacts on marine life has left the federal regulator, Fisheries and Oceans Canada (DFO), challenged to adequately assess the risk, particularly to fish. This uncertainty challenges the regulatory permitting process; without regulatory approval, developers cannot execute the planned project scope nor raise additional private sector funding to move forward.
Many perceive the greatest potential risk of tidal turbine operations as collisions between marine animals and turbines blades. These types of interactions are difficult to observe directly: both because of the fast flowing, turbid waters of tidal energy sites and because of the limitations of monitoring instruments which have been designed for use in more benign marine environments. The Risk Assessment Program (RAP) for tidal stream energy is designed to create a detailed, credible assessment tool to gauge the probability that fish will encounter a tidal device. RAP is a collaborative effort between the Fundy Ocean Research Centre for Energy (FORCE), Ocean Tracking Network at Dalhousie University, the Mi’kmaw Conservation Group, Acadia University, and Marine Renewables Canada.
A key deliverable of RAP is an encounter rate model (ERM): a mathematical model that estimates the frequency with which a stationary entity encounters a moving one — in this case, the probability that a fish will occupy the same volume of water as tidal stream turbine, thereby encountering the device (assuming no avoidance behavior by the fish). ERMs have become a standardized permitting tool for assessing the risk of offshore wind projects; until now, little work has been done to apply the concept to tidal turbine projects. The development of an ERM tailored specifically to tidal devices in the Bay of Fundy’s Minas Passage will be game changing. The probability of fish-turbine encounters will be determined by combining two complementary data sets: physical oceanographic (hydrodynamics), and biological (fish distribution). A radar-based flow atlas is the key input for determining water movement and direction; acoustic fish-tagging provides the data of central interest on different fish species and their location. With unprecedented reach and accuracy, RAP combines data on water flow with fish location to understand fish movement in the Minas Passage, in real time.
RAP partners will be able to estimate, for the first time, the probability that a fish will encounter a turbine at specific locations in Minas Passage. That will give regulators, Rights Holders, fishers, developers and other stakeholders a clearer understanding of the potential risks to fishes of commercial, cultural, and conservation value in the Bay of Fundy in advance of tidal turbine deployments. The inclusive design of RAP, which brings together many participants with diverse interests and concerns around the Fundy ecosystem, is also establishing the foundation for future environmental effects monitoring programs and best practices. The RAP project is entering its third and final year. This report provides an update of the key program components: 1) flow atlas; 2) fish atlas; and 3) modelling.