A Lesser Known Dolphin Found In BC Waters
Many of us assume that Pacific white-sided dolphins and killer whales are the only type of dolphin to be found in BC waters, but this is not the case! If one ventures far enough offshore, the distinctive northern right whale dolphin can be spotted. The BC Cetacean Sightings Network only has a handful of northern right whale dolphin sightings, and not surprisingly all but one of these reports are located offshore. In 1998, a solo northern right whale dolphin was spotted in McNeill Bay, north of Oak Bay near Victoria (see photo on the right).
Northern right whale dolphins have a characteristic black and white coloration with a white patch that runs along the underside of the body from the flukes to the throat and widens at the urogenital region. There is another white patch underneath the rostrum and the flippers. One of the most striking features (or lack thereof) is that they do not have a dorsal fin. This feature alone can make them relatively easy to identify. In fact, northern right whale dolphins were named after the massive right whale, another species lacking a dorsal fin. Because this species of dolphin lives so far from the coast in oceanic environments, details of their overall biology, life history, and behavior is poorly understood. Northern right whale dolphins also have a southern counterpart, the southern right whale dolphin. This species is quite similar in appearance, but with more extensive white markings, and they live in the southern hemisphere.
Northern right whale dolphins are roughly 3m long, with males being larger than females. They can be found in cool, temperate waters and sub Arctic regions from the Gulf of Alaska to Southern California. Like the Pacific white-sided dolphin, the northern right whale dolphin is a highly gregarious species- and can be seen travelling in pods numbering 2000-3000 animals! They are also extremely fast swimmers, reaching speeds of 40km/hr. Observing aerial behavior like breaching and belly flops is common. Similar to other toothed cetaceans, northern right whale dolphins rely on echolocation to navigate dark seas and locate prey. Hydrophone recordings of these animals reveal pulsed vocalizations and clicks with high repetition.
Mating behavior is rarely observed in northern right whale dolphins; what scientists do know is that females reach sexual maturity slightly earlier than males, but both sexes are ready to mate around at 10 years of age. Calves are seen in winter and early spring and born a grayish-brown color before developing the black and white adult coloration after 1 year.
Northern right whale dolphins have also been known to interact with other species; it is not uncommon for them to be spotted with Pacific white-sided dolphins, pilot whales, and Risso’s dolphin as they all occupy similar habitat which is typically deep water off the continental shelf or where deep waters approach the coast. These areas tend to be highly productive in terms of food supply, and it is here where the dolphins can forage for their prey of choice- squid, and also hake, saury, and lanternfish. The dolphins themselves have few predators, but killer whales and large sharks have been known to prey on them. Unfortunately for northern right whale dolphins, accidental catch in the fisheries operations is their number one threat. In fact, in the mid-1980’s, incidental takes of northern right whale dolphins by the squid driftnet fishery operated by Japan, Korea and Taiwan numbered 15,000-24,000 dolphins per year. The good news is that in 1993, the UN issued a moratorium on large-scale high-seas driftnets. This has reduced the danger to offshore cetaceans, however, the continued use of driftnets to catch billfish, sharks, squid, and tuna inside the exclusive economic zones of North Pacific countries, and some continued illegal fishing on the high-seas, may result in the killing of unknown numbers of northern right whale dolphins each year.
Reporting your sightings helps researchers understand the distribution and abundance of BC’s cetaceans. You can participate directly in whale and dolphin conservation by reporting your sightings here. So if you’re lucky enough to spot a northern right whale dolphin, or any type of whale, dolphin, or porpoise for that matter, let us know!