A recent research study has discovered that critically endangered North Atlantic right whales are engaging in surface feeding at night, heightening their vulnerability to boat collisions. The study, recently published in the peer-reviewed journal PLOS One, highlighted the nocturnal surface feeding behavior of these whales, offering valuable insights to mitigate fatal encounters between the whales and vessels.
The 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 to 23 right whales in the Shediac Valley, located in the southern Gulf of St. Lawrence. The population of North Atlantic right whales, estimated at around 384 individuals, congregates in the Shediac Valley during the summer for feeding.
Utilizing these tags, Kirkham’s team captured video footage and collected data on the whales’ movements and swimming directions. The video recordings were crucial in observing the feeding behavior of right whales during daylight hours.
Kirkham employed these observations to train a machine learning algorithm capable of identifying nocturnal feeding behavior in right whales when visual identification was not feasible. The analysis revealed that the whales feed at the same depth as large vessels at night, increasing the risk of collisions.
While right whales typically feed near the sea floor during the day, they follow their primary food source, zooplankton, higher up in the water column at night. This behavior puts them in close proximity to large ships, heightening the likelihood of collisions.
Collisions with vessels and entanglements in fishing gear are the primary causes of mortality in the North Atlantic right whale population. This study could aid in shaping conservation strategies for the protection of these whales. Transport Canada and Fisheries and Oceans Canada are currently responsible for implementing protective measures for the whale population.
Fisheries and Oceans Canada stated that their efforts focus on preventing whale entanglements in fishing gear and enforcing seasonal fishing closures, with the study providing insights for tailored management measures. Transport Canada enforces speed restrictions and maintains a vessel exclusion zone in the Shediac Valley during the summer to reduce collision risks. However, Kirkham noted that the tagged whales spent a significant portion of their feeding time outside the exclusion zone, exposing them to vessel traffic.
In response, Transport Canada mentioned a right whale surveillance program employing visual and audio detection tools to safeguard whales from collisions, emphasizing the use of advanced technologies to detect whales and inform protective measures.
The government departments rely on the latest scientific research, monitoring data, and stakeholder feedback to formulate and enhance protective measures for the North Atlantic right whales.
