The white-beaked dolphin, Lagenorhynchus albirostris, is a robust oceanic dolphin found in the North Atlantic Ocean. The species was first formally described in 1846. Its scientific name, albirostris, translates to “white beak,” referencing a common identifying feature.
Physical Characteristics and Identification
The white-beaked dolphin has a compact body and a short, thick beak. Adults measure between 2.3 and 3.1 meters (7.5 to 10.2 feet) in length and weigh from 180 to 354 kilograms (397 to 780 pounds), with males being slightly larger than females. Their coloration is dark gray or black on their upper sides and back, transitioning to white on their belly.
Light gray or white patches appear on their sides and flanks, including an elongated white streak that starts above the flipper and extends along the flanks and over the back behind the dorsal fin. The beak is typically white, but can also be light gray or mottled with darker spots. They possess a large, tall, and curved dorsal fin located near the middle of their back, along with dark flippers and flukes.
Habitat and Behavior
White-beaked dolphins inhabit the cold temperate and subpolar waters of the North Atlantic Ocean. Their range extends from eastern North America, including areas like Massachusetts and Newfoundland, across to northern Europe, Scandinavia, Greenland, the United Kingdom, and the Barents Sea. They prefer waters less than 200 meters (650 feet) deep, favoring continental shelf seas. Seasonal movements occur, with dolphins moving south and offshore during winter and returning north and closer to shore as ice recedes in warmer months.
These dolphins are social animals, found in groups ranging from five to 30 individuals. They can form much larger aggregations, numbering up to 1,500 dolphins, particularly in areas with abundant food. These larger groups often consist of numerous smaller subgroups and include other species like fin whales, humpback whales, or Atlantic white-sided dolphins. White-beaked dolphins are known for energetic surface behaviors, frequently breaching, leaping, and riding the bow waves of vessels.
Communication among white-beaked dolphins involves a variety of sounds. They produce high-frequency clicks, used for echolocation. They also emit whistles, used for social communication.
Diet and Hunting Strategies
The diet of white-beaked dolphins consists of schooling fish species. Common prey include gadoids such as cod, haddock, and whiting, as well as herring and mackerel. They also consume cephalopods like squid and octopi, leading some fishermen in Canada to call them “squidhounds.”
White-beaked dolphins employ cooperative hunting strategies to capture their prey. They work together in pods to herd schools of fish, sometimes into tight “bait balls,” making it easier for individuals to feed. They hunt both near the water’s surface and along the ocean bottom. Echolocation is a primary tool for locating prey, especially in murky waters, allowing them to detect food sources by emitting clicks and interpreting the returning echoes.
Conservation Status and Threats
The white-beaked dolphin is classified as “Least Concern” by the IUCN Red List. Despite this, several threats impact their populations. Accidental entanglement in commercial fishing gear, known as bycatch, is a significant danger. Dolphins can become caught in gillnets, cod traps, and trawl nets, leading to injury or death.
Marine pollution poses a risk to white-beaked dolphins, including plastics and chemical contaminants that can impact their health and habitat. Climate change affects their environment by altering prey distribution and habitat availability, which can disrupt their foraging patterns. Underwater noise pollution, originating from shipping, industrial activities, and seismic surveys, interferes with their ability to communicate and echolocate, potentially disrupting feeding and navigation. White-beaked dolphins are also subject to targeted hunting in some areas, including waters off Canada, Greenland, Iceland, and Norway, where they are hunted for meat and oil. Ongoing monitoring and conservation efforts are undertaken to better understand and mitigate these threats.