A recent research study has discovered that critically endangered North Atlantic right whales are engaging in surface feeding behavior at night, heightening their vulnerability to collisions with boats. The study, recently published in the scientific journal PLOS One, highlighted the occurrence of nighttime surface feeding among North Atlantic right whales, offering valuable insights for preventing fatal collisions between the whales and marine vessels.
Lead author of the study, Jay Kirkham, a PhD student affiliated with Dalhousie University in Halifax, collaborated with the U.S.-based non-profit organization Ocean Alliance to attach tracking devices to 23 North Atlantic right whales in the Shediac Valley, an underwater valley located in the southern Gulf of St. Lawrence. This particular region serves as a feeding ground for a segment of the North Atlantic right whale population, estimated to be around 384 individuals, who congregate there during the summer months.
Kirkham explained that the tracking devices captured video footage and behavioral data, shedding light on the whales’ movement patterns and feeding habits. By analyzing the video footage, Kirkham observed the distinctive feeding behavior of right whales during daylight hours.
Utilizing these observations, Kirkham developed a machine learning algorithm capable of identifying nighttime feeding behavior in right whales when visual identification was not possible. The data revealed that the whales feed at a depth similar to that of large vessels during nighttime, thereby increasing the risk of collisions.
While North Atlantic right whales typically feed near the seabed during the day, Kirkham noted that they ascend in the water column at night in pursuit of their primary food source, zooplankton. This behavior brings them into close proximity with large ships navigating the area, leading to the heightened risk of collisions.
According to Kirkham, collisions with vessels and entanglement in fishing gear are the primary causes of mortality among the North Atlantic right whale population. The findings from this study could contribute to the development of conservation strategies aimed at protecting these endangered marine mammals.
Presently, Transport Canada and Fisheries and Oceans Canada are responsible for implementing protective measures for the North Atlantic right whale population. Fisheries and Oceans Canada emphasized that their efforts are focused on preventing whale entanglements in fishing gear and enforcing seasonal fishing closures, with the study providing valuable insights for tailoring management strategies to safeguard the whales.
Transport Canada, on the other hand, enforces speed restrictions and maintains a vessel exclusion zone in the Shediac Valley during the summer season to minimize the risk of collisions between boats and right whales. However, Kirkham highlighted that a significant portion of the tagged whales spent a considerable amount of their feeding time outside the designated vessel exclusion zone, leaving them vulnerable to ship traffic.
In response to these challenges, Transport Canada stated that they have implemented a right whale surveillance program utilizing visual and acoustic detection tools to mitigate the risk of collisions. The department emphasized the importance of employing advanced technologies and research findings to enhance protective measures for the whales.
Overall, the study’s findings underscore the critical importance of understanding the feeding behavior of North Atlantic right whales to mitigate the risks posed by maritime traffic and facilitate targeted conservation efforts for this endangered species.