Novel Marine Monitoring Network Could Improve Environmental Protections and Shipping Regulations in the Lower St. Lawrence

Researchers from McGill University and several partner institutions have developed an experimental monitoring network in the Lower St. Lawrence capable of simultaneously tracking seismic activity, water behavior, and marine traffic. The system utilizes ocean-bottom seismometers and land-based stations to provide a comprehensive view of the estuary's environment, detecting significantly more earthquakes than existing national systems. This integrated approach offers critical data for the shipping industry, as it highlights the intersection of vessel noise and whale habitats in one of Canada's busiest maritime corridors.

The experimental network was deployed between Rimouski and Sept Îles from September to May during the 2023–2025 period, strategically avoiding the summer fishing season to protect equipment from trawling damage. Led by Professor Yajing Liu of McGill’s Department of Earth and Planetary Sciences, the team utilized ocean-bottom seismometers from the National Facility for Seismological Investigations alongside coastal and land-based stations. These sensors recorded data continuously at a rate of 250 points per second, allowing researchers to use spectral analysis to distinguish between various signals, including whale calls, ship traffic, and mining blasts.

A primary finding of the study is the direct overlap between shipping activity and marine life. The researchers observed that ship noise and whale calls often occur at the same time and place, suggesting that vessel traffic may be interfering with whale communication. This is particularly significant for the Lower St. Lawrence, which serves as both a critical whale habitat and a major shipping corridor. The network also proved more sensitive than the National Earthquake Monitoring System, detecting twice as many seismic events and identifying shallow blast events that were previously unrecorded.

Beyond seismic and acoustic monitoring, the system captured clear signals related to tidal activity, which could significantly improve ocean circulation models. Current models often rely on surface measurements, but the ocean-bottom sensors provide insights into the bottom of the water column where nutrient-rich currents influence whale feeding and migration patterns. The researchers, including contributors from Natural Resources Canada, UQAM, and Dalhousie University, believe this multi-purpose dataset will be instrumental in shaping future marine policy and traffic regulations to better balance commercial shipping needs with environmental conservation.