Risk Assessment Program fish tagging underway

Published October 7, 2021

Photo credit: Nicolas Winkler Photography

The Risk Assessment Program (RAP) for Tidal Energy is designed to create a tool to assess the probability that fish will encounter a tidal device in the Bay of Fundy’s Minas Passage. This probability will be determined by combining two data sets: physical (ocean movements) and biological (fish movements) to build encounter rate models. 

As part of the project, researchers tagged 50 Alewife, 26 American Shad and 15 Spiny dogfish between June and October, and tagging of Atlantic sturgeon remains underway.

Why are fish being tagged as part of the RAP project?
RAP is building the largest data set of fish movement in the Bay of Fundy, and developing a simple user interface to make this data available to people for the first time. 

To build this fish “atlas” for the Bay of Fundy, researchers are building maps of fish distributions using existing acoustic telemetry fish tagging data for nine species. The species selected are based on expected availability, conservation concern or value to commercial, recreation, and Mi’kmaq fisheries. In addition, new tags will be deployed on five of the species, with the goal of using the new data to verify the accuracy of the atlas. 

Both the integration and accessibility of this data set is unprecedented, and can serve as an important tool for considering the potential impacts of any activity in the Bay of Fundy on the marine ecosystem. 

The focus of RAP is tidal energy development. The Bay of Fundy has enormous potential to be a source of clean, renewable electricity and help respond to the impacts of climate change (like ocean acidification, sea level rise, and coastal erosion). While international research around tidal stream technology (which often resemble windmills under the water) suggests fish and marine mammals generally avoid these devices, more research is required to understand any potential effects in Fundy’s unique ecosystem.

That’s where RAP can help, giving regulators, Rights holders, community stakeholders, and technology developers a better understanding of the potential risks to fishes of commercial, cultural, and conservation value in the Bay of Fundy in advance of tidal turbine deployments, and informing future monitoring programs.

RAP is a collaborative effort between Acadia University, the Fundy Ocean Research Centre for Energy (FORCE), Marine Renewables Canada (MRC), the Confederacy of Mainland Mi’kmaq / Mi’kmaw Conservation Group (MCG), the Ocean Tracking Network (OTN) at Dalhousie University, and a number of Mi’kmaq and local fishers.

How does acoustic telemetry work?
Acoustic telemetry involves using sound (acoustics) to relay information across open space (telemetry). Researchers implant acoustic transmitters (or “tags”) in the fish they study. Each tag emits a unique pattern of sound pulses that are heard and understood by underwater tracking stations (receivers). These pulses are recorded by the receiver as the ID code for that individual fish, along with the date and time that it was detected. As fish swim through our network of over 12 tracking stations, data is generated that helps us better understand their distribution and behaviour.

What are the different fish species that are being tagged and how many?
The program is tagging five species with a total of 111 individual tags: 50 Alewife, 26 American shad, 10 Atlantic sturgeon (will be double tagged [20 total] with 69 kHz and 180 kHz tags) and 15 Spiny dogfish in 2021.

When is the fish tagging happening?
Researchers tagged 50 Alewife and 26 American Shad in June 2021, and tagging of Atlantic sturgeon and Spiny dogfish is taking place in October.

What is the location of the fish tagging?
Field work during the first year of the project is predominantly occurring in the Minas Basin and adjacent tributaries.

Who is conducting the fish tagging work as part of this project?
The Mi’kmaw Conservation Group, Acadia University, Dalhousie University, and a number of Mi’kmaw and local fishers.

Does fish tagging hurt the fish?
No.  The fish are anesthetized prior to tag implantation and are allowed a recovery period prior to being released.  Those conducting the tagging have taken the University of Prince Edward Island's fish surgery course, and these procedures are in line with the established Animal Care Protocols at Acadia and Dalhousie.

What types of tags are being used?
Acoustic tags come in a variety of styles and can last up to a decade. Some tags also contain sensors that relay environmental conditions such as water temperature and depth. A variety of acoustic tags are being used as part of the RAP project, and divided between the commonly used frequencies of 69 kHz and 180 kHz. The type of tag is largely dependent on the size of the fish (smaller fish like alewife get smaller tags) and guided by previous research selections. For each species, some of the tags will also be carrying a pressure sensor to provide information on the fish’s vertical position in the water column.

Where are the receivers located?
The receivers are deployed in the Minas Passage, extending from the FORCE tidal demonstration site in a southerly direction towards the deeper channel near the center of the passage.

What do I do if I catch a tagged fish?
Here are a couple rules of thumb and steps to take if you catch a tagged fish:

  • ​Take note of the TAG number on the external tag. This is the fish’s ID number in the study. If possible, get a close-up picture of the tag number, measure the fish, and take note of the location where it was caught.
  • Release or Return. You have two choices when you catch a tagged fish:
    • Release the fish safely with the tag intact so it continues to provide data to the study (after recording the tag number, catch location and size); or
    • Return the tag to the MCG after you harvest the fish.

Whether you choose to release the fish or harvest it, please contact Joe Beland at the MCG (jbeland@mikmawconservation.ca; 902-890-6237) to report the location of catch and tag number. You’ll be asked to provide your name and a mailing address so that a $50 gift card can be provided in appreciation of you releasing the fish, or harvesting it and returning the tag.

Is the meat from a tagged fish safe to consume?
Yes. The anesthetic that is used during the implantation procedure is worn off (metabolized) by the fish after 24-hours.  Most of the tagged fish will be held in tanks for 24-hours before they are released. When you report the tag to the MCG we’ll be able to tell you when the fish was tagged.

If you have more questions about the RAP project please contact us