A recent research study has discovered that North Atlantic right whales, which are critically endangered, are engaging in nighttime surface feeding, putting them at higher risk of being struck by boats. The study, recently published in the peer-reviewed journal PLOS One, has documented this behavior in the whales and highlights the need for measures to prevent fatal collisions 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, a submerged valley in the southern Gulf of St. Lawrence. This area serves as a feeding ground for a portion of the North Atlantic right whale population, estimated to be around 384 whales.

The tags collected video footage and data on the whales’ movements and feeding behavior. Kirkham utilized this information to train a machine learning algorithm to identify nighttime feeding behavior, revealing that the whales feed at the same depth as large vessels at night, heightening the risk of collisions.

While these whales typically feed near the sea floor during the day, they follow their food source, zooplankton, higher up in the water column at night. This behavior increases the likelihood of overlap with passing ships, posing a threat of collisions and entanglements, which are the primary causes of death among the population.

Measures currently in place by Transport Canada and Fisheries and Oceans Canada aim to protect the whales, such as speed restrictions, vessel exclusion zones, and surveillance programs. However, the study suggests that additional tailored management measures may be necessary to safeguard the North Atlantic right whales effectively.