A recent research study has discovered that North Atlantic right whales, a critically endangered species, are engaging in surface feeding at night, which puts them at a higher risk of being struck by boats. The study, recently published in the peer-reviewed journal PLOS One, observed this nighttime feeding behavior in North Atlantic right whales and suggests the findings could help prevent 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 attach tags to 23 right whales in the Shediac Valley, an underwater valley in the southern Gulf of St. Lawrence. This valley serves as a summer feeding ground for a portion of the North Atlantic right whale population, estimated to consist of around 384 whales.
The tags collected video footage and data on the whales’ movements and feeding behavior. Kirkham utilized the video footage to analyze the whales’ feeding patterns during daylight hours. He described how the whales slow down significantly when they open their mouths to feed on zooplankton, necessitating increased effort as they kick their tails faster to compensate.
Through the collected data, it was revealed that at night, the whales feed at a depth similar to that of large vessels, heightening the risk of collisions. While the whales typically feed closer to the sea floor during the day, they follow their food source higher up in the water column at night.
Collisions with ships and entanglement in fishing gear are major causes of death among North Atlantic right whales. The study aims to contribute valuable insights for conservation efforts aimed at protecting these endangered animals. Current protection measures for the whale population are overseen by Transport Canada and Fisheries and Oceans Canada.
Fisheries and Oceans Canada stated that their measures focus on preventing whale entanglements in fishing gear and enforcing seasonal fishing closures, emphasizing the importance of tailored management strategies to safeguard North Atlantic right whales. Transport Canada, on the other hand, implements speed restrictions and a vessel exclusion zone in the Shediac Valley during the summer to reduce the risk of collisions between boats and whales in the area.
Despite these measures, Kirkham noted that the tagged whales spent a considerable amount of their feeding time outside the vessel exclusion zone, exposing them to ship traffic. Transport Canada highlighted their right whale surveillance program, which utilizes visual and audio detection tools to protect the whales from collisions and inform protective measures when whales are present.
The department stressed the use of the latest scientific research, monitoring data, and stakeholder feedback to shape their protection measures and ensure the welfare of North Atlantic right whales.