A recent research study indicates that critically endangered North Atlantic right whales are now feeding closer to the ocean’s surface during nighttime, which heightens their vulnerability to collisions with boats. The study, recently published in the peer-reviewed journal PLOS One, focuses on documenting the behavior of North Atlantic right whales as they feed near the surface at night. This new insight could help in developing strategies to prevent fatal encounters between the whales and marine vessels.
The primary researcher of the study, Jay Kirkham, a doctoral student at Dalhousie University in Halifax, collaborated with the U.S.-based non-profit organization Ocean Alliance to attach tracking devices to 23 right whales in the Shediac Valley, an underwater valley situated in the southern Gulf of St. Lawrence. This specific area attracts a portion of the North Atlantic right whale population, estimated to be around 384 whales, each summer for feeding.
Utilizing the data collected by the tags, including video footage and movement patterns of the whales, Kirkham observed the whales’ feeding behavior during both day and night. His analysis revealed that the whales tend to feed at a similar depth as large vessels during the night, which increases the risk of collisions. Although right whales typically feed near the sea floor during daylight hours, they shift their feeding habits to follow zooplankton higher up in the water column at night.
Kirkham employed machine learning algorithms to recognize nighttime feeding behaviors when direct observation was not feasible. This data underscores the potential danger of overlap between whales and ships in the same depth range. Collisions with vessels and entanglements in fishing gear are identified as significant threats to the whale population, emphasizing the importance of implementing conservation measures.
Current protection measures for North Atlantic right whales are overseen by Transport Canada and Fisheries and Oceans Canada. These measures include speed restrictions and a vessel exclusion zone in the Shediac Valley during the summer to minimize the risk of collisions. However, Kirkham noted that a substantial portion of the tagged whales’ feeding activities occur outside the designated exclusion zone, exposing them to ship traffic.
Both departments leverage the latest scientific research and stakeholder feedback to inform their protective measures. Fisheries and Oceans Canada highlighted the study’s potential role in designing tailored management strategies to safeguard North Atlantic right whales, focusing on preventing entanglements and enforcing fishing closures. Transport Canada employs a surveillance program utilizing visual and audio detection tools to enhance whale protection efforts, especially during periods of increased ship traffic.