A recent research study has revealed that critically endangered North Atlantic right whales are engaging in surface feeding at night, a behavior that elevates their vulnerability to collisions with boats. The study, recently published in the peer-reviewed journal PLOS One, presents new findings on nighttime feeding habits of North Atlantic right whales, offering insights to mitigate fatal encounters with vessels.
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 attach tags on 23 right whales in the Shediac Valley, an underwater valley located in the southern Gulf of St. Lawrence, where a portion of the estimated 384 North Atlantic right whale population congregates during the summer months.
Utilizing tags equipped with video recording capabilities and tracking data, the research team monitored the whales’ movements and feeding behaviors. Kirkham explained that the video footage captured during the day illustrated the unique feeding mechanisms of right whales, showcasing how they adapt their swimming patterns to feed efficiently.
By employing machine learning algorithms trained on these observations, the researchers identified that the whales feed at a similar depth to large vessels at night, heightening the risk of collisions. While the whales traditionally feed near the seabed during the day, they ascend in the water column at night to pursue their primary food source, zooplankton.
Kirkham emphasized that the overlap in feeding locations between whales and ships poses significant dangers, as collisions and entanglements with vessels and fishing gear are major contributors to the whales’ mortality rates. The findings from this study could aid in developing tailored conservation strategies for the protection of North Atlantic right whales.
Current protection efforts for the whale population are overseen by Transport Canada and Fisheries and Oceans Canada, focusing on measures to prevent 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 collisions between boats and right whales in the area.
Despite these protective measures, Kirkham noted that the tagged whales spent a significant portion of their feeding time outside the exclusion zone, exposing them to potential ship traffic. Transport Canada mentioned employing a comprehensive right whale surveillance program that utilizes visual and audio detection tools to safeguard the whales from collisions, emphasizing the importance of leveraging scientific research and stakeholder feedback to enhance protective measures.
The study findings are expected to guide the development of targeted management strategies to safeguard North Atlantic right whales, emphasizing the urgency of addressing the risks associated with their nighttime feeding behaviors.