A recent research study has discovered that critically endangered North Atlantic right whales are engaging in nighttime surface feeding, which puts them at a higher risk of being struck by boats. The study, recently published in the peer-reviewed journal PLOS One, highlighted this behavior in the whales and presented new findings that could aid in preventing fatal collisions between the whales and 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 tag 23 right whales in the Shediac Valley, located in the southern Gulf of St. Lawrence. This valley serves as a feeding ground for a segment of the North Atlantic right whale population, estimated at around 384 individuals during the summer months.
Kirkham explained that the tags collected video footage and data on the whales’ movements and swimming patterns. By analyzing the video footage, he observed the whales’ feeding behavior during daylight hours. He described how the whales slow down when feeding by opening their mouths, requiring them to exert more effort by increasing the movement of their tails.
Utilizing these observations, Kirkham trained a machine learning algorithm to identify nighttime feeding behavior in right whales when visual identification was not feasible. The data revealed that the whales feed at a similar depth to large vessels during the night, heightening the risk of collisions.
While right whales typically feed near the sea floor during the day, they follow their food source, zooplankton, higher up in the water column at night. This behavior puts them in close proximity to passing ships, increasing the likelihood of collisions. Kirkham emphasized that ship collisions and entanglement in fishing gear are the primary causes of death among the right whale population, underscoring the importance of conservation efforts.
Both Transport Canada and Fisheries and Oceans Canada are actively involved in overseeing protection measures for the North Atlantic right whales. Fisheries and Oceans Canada focuses on preventing entanglements in fishing gear and enforcing seasonal fishing closures based on the study’s insights. Meanwhile, Transport Canada implements speed restrictions and a vessel exclusion zone in the Shediac Valley during the summer to mitigate collision risks.
Despite these measures, Kirkham noted that a significant portion of the tagged whales spent a quarter of their feeding time outside the vessel exclusion zone, leaving them vulnerable to ship traffic. Transport Canada highlighted its right whale surveillance program, which utilizes visual and audio detection tools to safeguard the whales from collisions and enhance protective measures during their presence.
The department emphasized its commitment to leveraging the latest scientific research, monitoring data, and stakeholder feedback to inform and enhance protection measures for the vulnerable North Atlantic right whales.
