A recent research study has discovered that critically endangered North Atlantic right whales are engaging in nighttime surface feeding, which poses an increased risk of collisions with boats. The study, recently published in the peer-reviewed journal PLOS One, identified this behavior in the whales and suggests potential strategies to prevent fatal encounters between the whales and vessels.
The lead author of the study, Jay Kirkham, a PhD student at Dalhousie University in Halifax, collaborated with the U.S.-based non-profit Ocean Alliance to tag 23 North Atlantic right whales in the Shediac Valley, located in the southern Gulf of St. Lawrence. The Shediac Valley serves as a feeding ground for a portion of the estimated 384 North Atlantic right whale population during the summer months.
By utilizing tags that captured video footage and movement data of the whales, Kirkham observed and recorded the whales’ feeding behavior during both day and night. He explained that when right whales feed, they open their mouths creating a “parachute-like” effect that slows them down, leading to increased tail movements to compensate for the drag.
The study further employed machine learning algorithms to identify nighttime feeding behavior in the whales, revealing that they feed at similar depths to large vessels during the night, heightening the risk of collision incidents. While right whales typically feed near the sea floor during the day, they follow their food source, zooplankton, to higher levels in the water column at night.
Collisions with ships and entanglements in fishing gear are identified as the primary causes of mortality in the North Atlantic right whale population. The findings of this study could potentially guide conservation efforts aimed at protecting these whales. Presently, Transport Canada and Fisheries and Oceans Canada are responsible for implementing protective measures for the whale population, focusing on reducing entanglements in fishing gear and enforcing seasonal fishing closures.
Transport Canada enforces speed restrictions and a vessel exclusion zone in the Shediac Valley during the summer to minimize the risk of boat-whale collisions. Despite these measures, Kirkham noted that the tagged whales spent a significant portion of their feeding time outside the exclusion zone, exposing them to ship traffic.
In response to the study, Fisheries and Oceans Canada stated that the research could aid in developing tailored management measures to safeguard North Atlantic right whales. Transport Canada highlighted its surveillance program dedicated to whale protection, utilizing visual and audio detection tools to mitigate collision risks. The department emphasized the use of current scientific research, monitoring data, and stakeholder feedback to inform protective strategies.
Overall, the study sheds light on the behavioral patterns of North Atlantic right whales, underscoring the importance of conservation efforts to ensure the survival of this endangered species.