Image: Acoustic tags (1) are small transmitters that allow researchers to track fish underwater; this data is captured by acoustic receivers (2)

The risk assessment program (RAP) for tidal stream energy is intended to create a detailed, credible assessment tool to gauge the probability that a fish will encounter a tidal device.

“That way, the risks are better understood,” says FORCE science director Dr. Dan Hasselman, “We’re building a tool to give us a better understanding of any potential risks to marine life in advance of turbine deployment”.

RAP involves assembling the largest ever data set of fish distribution in the Bay of Fundy.

“Over the last decade, hydroacoustic receivers deployed throughout the Bay of Fundy have collected movement data from a variety of fish species carrying acoustic tags,” says Dr. Fred Whoriskey, executive director of the Ocean Tracking Network at Dalhousie University. “These data originate from a diverse series of separate research programs based in Canada and the United States, and our goal is to collaborate with all of the principal investigators to put them all together.”

RAP provides an opportunity for an ecosystem-wide approach: connecting a diversity of studies with observations on everything from large predators (like white sharks) to small zooplankton filter feeders (such as alewives). The information from these fish tagging projects will help to assess potential impacts on animals at multiple trophic levels.

The work builds on existing fish monitoring work at FORCE: ocean technologists have already collected over 400 hours of hydroacoustic sensor data, running transects up and down the entire test site to measure the distribution of fish.

Says Hasselman: “Our turbine monitoring work remains critical to measuring any potential environmental effects, but the RAP tool, using tagging data, gives everyone an early idea of what fish are doing at a particular site. We’re coming at the problem in a whole new way.”

Dr. Charles Bangley, a marine biologist working on the RAP tool with both MCG and Dalhousie University says: “So far, we’ve be able to add data on seven different species, including alewife, American shad, Atlantic salmon, Atlantic sturgeon, striped bass, white sharks, and Atlantic tomcod. We’re also hoping to add data on American eel and spiny dogfish.”

The list includes anadromous species, that move up freshwater rivers to spawn, like American shad, as well as purely saltwater, migratory species found mostly in the open ocean – some of which are culturally significant to the Mi’kmaq and/or endangered, like the inner Bay of Fundy Atlantic salmon.

“The goal is species-specific risk assessment,” says Joe Beland, fisheries advisor and marine biologist for the Mi’kmaw Conservation Group (MCG). “We’re acquiring new acoustic tags and receivers for the study – our aim is to prep first the first round of tagging in spring 2021, and then follow-up for round two in 2022.”

Adds Bangley: “Ultimately we’re trying to generate a map that shows us where we expect certain species of fish to be.”

RAP is funded in part by the Government of Canada and the Province of Nova Scotia. Key partners include Acadia University, Fundy Ocean Research Centre for Energy (FORCE), Marine Renewables Canada (MRC), Mi’kmaw Conservation Group (MCG), Confederacy of Mainland Mi’kmaq, Ocean Tracking Network (OTN), and Dalhousie University. Read more about RAP here.