A recent research study has revealed that critically endangered North Atlantic right whales are engaging in nighttime surface feeding, a behavior that heightens their vulnerability to boat collisions. The study, recently published in the peer-reviewed journal PLOS One, highlighted this nocturnal feeding habit among North Atlantic right whales, offering valuable insights to mitigate fatal encounters between the whales and marine vessels.
The study’s primary investigator, Jay Kirkham, a doctoral candidate at Dalhousie University in Halifax, collaborated with the U.S.-based non-profit Ocean Alliance to attach tracking devices to 23 right whales in the Shediac Valley, an underwater valley located in the southern Gulf of St. Lawrence. Each summer, a segment of the North Atlantic right whale population, estimated at around 384 individuals, congregates in the Shediac Valley for feeding.
Kirkham explained that the tracking devices captured video footage and behavioral data, shedding light on the whales’ movements and feeding patterns. By analyzing the video recordings, Kirkham observed the distinct feeding behavior of right whales during daylight hours.
The findings were utilized to train a machine learning algorithm capable of identifying nighttime feeding behavior in right whales when visual identification was not feasible. The data demonstrated that the whales feed at depths comparable to large vessels during nighttime, increasing the risk of collisions.
While North Atlantic right whales typically feed near the ocean floor during the day, they ascend in the water column at night to pursue their primary food source, zooplankton. Kirkham emphasized that this behavior places the whales in vertical proximity to passing ships, heightening collision risks.
Collisions with ships and entanglement in fishing gear are identified as major threats to the right whale population, underscoring the importance of implementing conservation measures. Presently, Transport Canada and Fisheries and Oceans Canada oversee protective measures for the whales.
Fisheries and Oceans Canada emphasized that its current initiatives concentrate on preventing whale entanglements in fishing gear and enforcing seasonal fishing closures. They emphasized that the study findings could facilitate the development of tailored management strategies to safeguard North Atlantic right whales.
Transport Canada enforces speed restrictions and maintains a vessel exclusion zone in the Shediac Valley during the summer to reduce the likelihood of boat-whale collisions in the region. 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, Transport Canada highlighted its right whale surveillance program, which employs visual and audio detection tools to safeguard whales from collisions. The department stressed the significance of utilizing cutting-edge research, monitoring data, and stakeholder feedback to enhance protective measures for the whales.