A Rigorous Protocol for Studying Large Rorquals

August 20, 2025. This morning, the Large Rorqual Project team is gathered on the docks of Tadoussac’s marina. We slip on our hats, gloves, and “Mustangs,” the colourful dry suits so essential to staying comfortable on the water. Later, we say goodbye to our colleagues from the St. Lawrence Beluga Project, who are departing for a day aboard the Antarès just as we prepare to board the BpJAM. I’m accompanied by Laurence, today’s captain; Janie, who’s been tasked with photo-identification; and Mathieu, who will be operating the drone.

Since 1985, the Large Rorqual Project team has been carrying out long-term monitoring of large rorquals (namely blue, fin, and humpback whales) that frequent the St. Lawrence Estuary in order to better understand their habits and explore ways to co-exist with them. The project has recently been divided into two components: the photo-identification census and the Large Rorqual Observatory, the latter aiming to collect data on the physical condition of individual whales.

The GREMM team’s protocol for counting fin whales consists primarily of following transects (precise routes) on the water and stopping at various pre-established strategic points to log their observations. There are 13 pre-determined points covered by the team in this section of the Lower Estuary. Thirteen points means thirteen observation stations. Each observation station lasts 10 minutes and begins as soon as Laurence brings the inflatable boat to a stop. At this point, Janie climbs onto a platform at the bow of the boat and starts taking note of any ships, kayaks, cargo vessels, and Zodiacs within a 2,000-metre radius. All this information is recorded in real time using an iPad. This saves a great deal of time for data processing once we’re back on dry land! Wind and wave conditions (among other parameters) are also noted at each station.

Then it’s time to tally all the marine mammals within the aforementioned radius. Everything counts, from harbour seals to blue whales!

• If a fin whale is spotted, we stop noting information at the station and slowly make our way toward it.
• The same principle applies if a spout is seen while travelling between two stations.
• If no animals are seen, we wait for the full 10 minutes to pass before heading to the next observation station. The absence of any large rorquals is significant data in itself!

Once it gets close to a humpback, the BpJAM comes to a stop: Time to get out the camera and the drone! While Laurence attempts to position the craft at an optimum angle for photos, Janie gets the camera ready and Mathieu deploys the drone’s arms and propellers.

Sometimes the research team finds itself working at sites frequented by whale-watching cruises, as was the case during the encounter with H859 not far from the ferry terminal in Les Escoumins. The tour boats already present before the arrival of BpJAM have been sharing information on the animal’s behaviour on Channel 8 of the VHF marine radio. The research team takes this opportunity to share its observations of the day and the area covered. The BpJAM team uses the same channel to notify the boats of the drone’s takeoff. Camera and drone are then deployed as they were earlier with the humpback whale H943, which was encountered farther offshore this time while sailing between two stations.

The best way to spot a fin whale is to catch sight of its powerful blow as it surfaces to breathe. A little experience and a sharp eye make it easy to notice the wisps of condensation rising above the water. Experts can even identify the species simply based on the shape of the spout. And then we start all over again with a drone launch and a photo shoot!