A recent research study has discovered that critically endangered North Atlantic right whales are engaging in nighttime surface feeding, which puts them at a higher risk of being struck by vessels. The study, recently published in the peer-reviewed journal PLOS One, highlights this behavior shift in the whales and its potential implications for preventing fatal collisions with boats.
Led by Jay Kirkham, a PhD student at Dalhousie University in Halifax, the research team collaborated with the U.S.-based non-profit Ocean Alliance to tag 23 right whales in the Shediac Valley, an underwater valley in the southern Gulf of St. Lawrence. This region serves as a feeding ground for a portion of the approximately 384 North Atlantic right whales during the summer months.
The tags attached to the whales captured video footage and data on their movement patterns and feeding behavior. Kirkham utilized this footage to observe the whales’ feeding habits during both day and night. He explained that the whales exhibit different feeding behaviors at night, where they feed closer to the ocean’s surface, potentially leading to increased collision risks with vessels.
While these whales typically feed near the sea floor during the day, they adjust their feeding behavior at night to pursue zooplankton at higher depths in the water column. Kirkham emphasized that this change in behavior places the whales in vertical proximity to large ships passing through the area, heightening the chances of collisions.
Vessel collisions and fishing gear entanglements are major threats to the North Atlantic right whale population. The study’s findings could aid in the development of conservation strategies to safeguard these endangered marine mammals. Current protection measures overseen by Transport Canada and Fisheries and Oceans Canada include speed restrictions, seasonal fishing closures, and a vessel exclusion zone in the Shediac Valley to minimize the risk of interactions between boats and right whales.
Despite these measures, Kirkham noted that the tagged whales spent a significant portion of their feeding time outside the designated vessel exclusion zone, leaving them vulnerable to ship traffic. Transport Canada employs a surveillance program utilizing visual and audio detection tools to enhance whale protection efforts. The department emphasized the importance of integrating scientific research and stakeholder feedback to continually improve protection measures for North Atlantic right whales.