Northern Right Whale Dolphin
About the Species
Northern right whale dolphins are found in the deep, cold to warm temperate waters of the Pacific Ocean. They usually travel in groups of 100 to 200 individuals but sometimes travel in groups of up to 3,000. They are “acrobatic” swimmers and can leap more than 20 feet over the surface of the water.
Northern right whale dolphins are the only species of dolphin in the North Pacific Ocean without a dorsal fin. At sea, they are sometimes mistaken for herds of fur seals and sea lions due to their dark, streamlined body.
Northern right whale dolphins, like all marine mammals, are protected under the Marine Mammal Protection Act. NOAA Fisheries and its partners are working to conserve northern right whale dolphins and further our understanding of this species through research and conservation activities.
NOAA Fisheries estimates population size in its stock assessment reports.
Scientists estimate that there are about 68,000 northern right whale dolphins in the entire North Pacific Ocean.
To manage northern right whale dolphins in U.S. waters, we have placed them into a California/Oregon/Washington stock. Based on the most recent surveys, our scientists estimate that there are about 26,000 dolphins in this stock.
Northern right whale dolphins are about 6.5 to 10 feet long and weigh about 130 to 250 pounds. Males are generally larger than females. Both males and females have a streamlined body with a short beak, sloping forehead, and a small fluke (tail). Their thin body can make them appear smaller than their actual size.
Northern right whale dolphins are one of the only species of dolphin in the North Pacific Ocean without a dorsal fin. Their dorsal side is shiny and black, while their underside is white. Young dolphins range in color from dark gray-brown to cream.
The southern right whale dolphin (Lissodelphis peronii), a related species, looks similar to the northern right whale dolphin. While both species are in the Lissodelphis genus, they differ in size, features, and color. Southern right whale dolphins are generally larger and whiter on their underside compared to their northern relatives. Southern right whale dolphins occur in cool temperate to subantarctic waters of the Southern Hemisphere.
Behavior and Diet
Northern right whale dolphins usually travel in groups of 100 to 200 individuals but are sometimes found in groups of up to 3,000. They are occasionally seen in mixed groups with other cetacean species, such as Pacific white-sided dolphins, Risso’s dolphins, and short-finned pilot whales.
Northern right whale dolphins are fast swimmers, reaching average speeds of 16 miles per hour and short bursts of 22 miles per hour. They make low, graceful leaps out of the water. When moving near the surface, they rarely show much of their body but will sometimes lift their tails out of the water and then slap them onto the surface. While they usually avoid vessels, groups of northern right whale dolphins will sometimes "surf" the waves created by vessels, especially when traveling in groups with other cetacean species.
Northern right whale dolphins can dive for up to six minutes to feed on small fish (e.g., hake and lanternfish) and cephalopods (such as squid and octopi) in deep waters. They have 37 to 54 pairs of small, cone-shaped teeth in each jaw.
Where They Live
Northern right whale dolphins are found in deep, cold and warm temperate waters from the outer continental shelf to oceanic regions throughout the North Pacific Ocean, between 30° north and 50° North. Their range includes the waters of western North America (northern Baja California to the Gulf of Alaska), Russia (Kamchatka), and Japan. They prefer water colder than 66° Fahrenheit and usually inhabit areas over the continental shelf (the edge of a continent below the ocean’s surface). They may occur in deep water close to the coast where there are submarine canyons and other features.
The distribution of northern right whale dolphins varies with the seasons. They usually migrate within their habitat as the water temperature changes. The dolphins move south during the colder winter and autumn months, then return north during the warmer spring and summer months.
Lifespan & Reproduction
Northern right whale dolphins live for 42 years or longer. Males and females become sexually mature around ten years of age. Females are pregnant for about one year and give birth to a single calf, usually during the summer. For females, there is a minimum of 2 years between each birth.
One of the main threats to northern right whale dolphins is becoming entangled or captured in fishing gear such as driftnets, gillnets, and purse seines. Entanglement in gear can injure or kill dolphins.
During the 1970s and 1980s, many northern right whale dolphins were taken in squid fisheries’ driftnets. These high mortality rates may have decreased northern right whale dolphin stocks. These squid fisheries have since been closed by international law.
Northern right whale dolphins are sometimes targeted and hunted for meat and oil in the Dall's porpoise harpoon drive fishery off of Japan.
Underwater noise pollution interrupts the normal behavior of northern right whale dolphins that rely on sound to communicate and echolocate. If loud enough, noise can cause permanent or temporary hearing loss. Noise interference from vessels, as well as industrial and military activities, disturbs northern right whale dolphins’ feeding, communication, and orientation.
In the Spotlight
Northern right whale dolphins, like all marine mammals, are protected under the Marine Mammal Protection Act.
Recovery Planning and Implementation
Overseeing Marine Mammal Health and Stranding Response
We work with volunteer networks in all coastal states to respond to marine mammal strandings including all dolphins and porpoises. When stranded animals are found alive, NOAA Fisheries and our partners assess the animal’s health and determine the best course of action. When stranded animals are found dead, our scientists work to understand and investigate the cause of death. Although the cause often remains unknown, scientists can sometimes attribute strandings to disease, harmful algal blooms, vessel strikes, fishing gear entanglements, pollution exposure, and underwater noise. Some strandings can serve as indicators of ocean health, giving insight into larger environmental issues that may also have implications for human health and welfare.
Marine Mammal Unusual Mortality Events
Northern right whale dolphins have never been part of a declared unusual mortality event. Under the Marine Mammal Protection Act, an unusual mortality event is defined as "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response." To understand the health of marine mammal populations, scientists study unusual mortality events.
Implementing the Pacific Offshore Cetacean Take Reduction Plan
In 1997, NOAA Fisheries implemented the Pacific Offshore Cetacean Take Reduction Plan. The plan requires measures to reduce bycatch of cetaceans, including northern right whale dolphins, in the California and Oregon drift gillnet fishery. The Pacific Offshore Cetacean Take Reduction Team continues to meet and recommend measures to further reduce bycatch and achieve MMPA goals.
Addressing Ocean Noise
Underwater noise threatens dolphin populations, interrupting their normal behavior and driving them away from areas important to their survival. Increasing evidence suggests that exposure to intense underwater sound in some settings may cause some dolphins to strand and ultimately die. NOAA Fisheries is investigating all aspects of acoustic communication and hearing in marine animals, as well as the effects of sound on whale behavior and hearing. In 2018, we revised our marine mammal acoustic technical guidance for assessing the effects of anthropogenic (human-caused) sound on marine mammals’ hearing.
Educating the Public
NOAA Fisheries aims to increase public awareness and support for northern right whale dolphin conservation through education, outreach, and public participation. We share information with the public about the status of northern right whale dolphins, as well as our research and efforts to promote their recovery.
All marine mammals, including northern right whale dolphins, are protected in the United States under the MMPA.
Key Actions and Documents
NOAA Fisheries conducts various research activities on the biology, behavior, and ecology of northern right whale dolphins. The results of this research are used to inform management decisions for this species.
Determining the size of northern right whale dolphin populations helps resource managers determine the success of conservation measures. Our scientists collect population information and present the data in annual stock assessment reports.
Monitoring Population Abundance and Distribution
Scientists observe northern right whale dolphins to record their numbers and distribution. By comparing numbers collected over multiple years, scientists can look for trends—i.e., whether the population is increasing, decreasing, or remaining stable during a given period.