A recent study has discovered that critically endangered North Atlantic right whales are now feeding closer to the ocean’s surface at night, which raises their vulnerability to boat collisions. Published in the peer-reviewed journal PLOS One, the study highlights the shift in the feeding behavior of these whales, offering valuable insights to mitigate fatal encounters with vessels.
The study’s lead author, Jay Kirkham, a PhD student at Dalhousie University in Halifax, collaborated with the U.S.-based non-profit Ocean Alliance to track 23 right whales in the Shediac Valley, a submerged valley in the southern Gulf of St. Lawrence. This region serves as a summer feeding ground for a segment of the North Atlantic right whale population, estimated at around 384 individuals.
Utilizing tags that captured video footage and movement data of the whales, Kirkham observed their feeding habits both during the day and at night. He noted that the whales exhibit different feeding patterns at night, aligning their feeding depth with that of large vessels, heightening the risk of collisions.
While these whales typically feed near the seafloor during the day, they ascend in the water column at night to pursue their main food source, zooplankton. This nocturnal feeding behavior places them in a vertical overlap with vessels passing through the area, increasing the likelihood of accidents.
Collisions with ships and entanglements in fishing gear pose significant threats to the North Atlantic right whale population. Kirkham’s study aims to inform conservation strategies to safeguard these endangered whales. Currently, Transport Canada and Fisheries and Oceans Canada oversee protective measures for the whales, including vessel speed restrictions and exclusion zones in critical habitats.
Fisheries and Oceans Canada highlighted that the study findings could aid in tailoring management strategies to shield North Atlantic right whales. Transport Canada emphasized its ongoing surveillance program, utilizing visual and audio detection tools to mitigate collisions and protect the whales effectively. Leveraging the latest research and stakeholder feedback, these departments continue to refine their protection measures for the whales.