Lissodelphis borealis

With no dorsal fin, a slender body shape that tapers steadily toward the tail, and small flippers and flukes, the northern right whale dolphin appears to be built for speed. It has been clocked at 34 km per hour and can dive as deep as 200 m to feed on deepwater fish. The species is common in deep waters of the continental shelf, or offshore waters, and it also occurs in large numbers where undersea canyons bring deep waters near the coast. It is known only from temperate North Pacific waters.

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Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

The northern right whale dolphin is found in deep, temperate waters of the North Pacific Ocean, between about 30°N and 50°N.

These cetaceans are found only in the northern Pacific Ocean, between the latitudes 35 degrees North and 51 degrees North.

Biogeographic Regions: pacific ocean (Native )

North Pacific

occurs (regularly, as a native taxon) in multiple nations

Global Range: North Pacific Ocean, mainly in moderate temperate waters. Mainly British Columbia to Baja California, Kuril Islands to Japan in western Pacific; sometimes north to Aleutians and Gulf of Alaska; in the eastern Pacific, apparently most common off central and southern California; at least as far south as 35 degrees north in the central Pacific (Jefferson and Newcomer 1993). Rare in Canadian waters (Baird and Stacey 1991). Eastern and western Pacific populations may be separated by an area of very low density south of the western Aleutians (Leatherwood and Reeves 1983).

Northern right whale dolphins have an unusually slender body shape, and they do not have a dorsal fin or ridge. They have small, curved flippers, and small flukes. They are mostly black, but they have a well defined white band on their belly. Males and females have the same body shape and color pattern, the only sexually dimorphism being that males can attain greater length (up to 3 meters) and weight than females.

Range mass: 90 to 113 kg.

Length: 310 cm

Length:
Range: 2-3.1 m males; 2-2.6 m females

Weight:
Range: up to 113 kg

Habitat and Ecology

Systems

• Marine

These animals live in deep continental shelf and offshore waters where the temperatures vary between 8 and 24 degrees C. They approach shore only where very deep water can be found near the coast.

Aquatic Biomes: benthic

oceanic, cold and warm temperate

Depth range based on 631 specimens in 1 taxon.
Water temperature and chemistry ranges based on 446 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): 11.144 - 16.503
  Nitrate (umol/L): 0.204 - 4.675
  Salinity (PPS): 30.381 - 33.496
  Oxygen (ml/l): 5.646 - 6.583
  Phosphate (umol/l): 0.330 - 0.800
  Silicate (umol/l): 1.436 - 16.169

Graphical representation

Temperature range (°C): 11.144 - 16.503

Nitrate (umol/L): 0.204 - 4.675

Salinity (PPS): 30.381 - 33.496

Oxygen (ml/l): 5.646 - 6.583

Phosphate (umol/l): 0.330 - 0.800

Silicate (umol/l): 1.436 - 16.169
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Habitat Type: Marine

Comments: Relatively deep continental shelf and offshore waters with temperatures of 8-24 C (see Jefferson and Newcomer 1993). Favors deeper-water habitats but does approach shore at the heads of deep canyons, especially in winter (Leatherwood and Reeves 1983).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Distribution tends to shift south and inshore during cooler months, north and offshore summer through fall; movement possibly are related to the availability of spawning squid (Leatherwood and Reeves 1983, Jefferson and Newcomer 1993).

Northern right whale dolphins feed mainly on squid and lanternfish, but they also eat other kinds of fish.

Animal Foods: fish; mollusks

Primary Diet: carnivore (Piscivore , Molluscivore )

Comments: Most common food items are market squid and lanternfish; other prey includes other squids, Pacific hake, saury, and epi- and mesopelagic fishes of the families Centrolophidae, Melamphaidae, Bathylagidae, and Paralepididae (Leatherwood and Reeves 1983, Jefferson and Newcomer 1993).

100,000 - 1,000,000 individuals

Comments: One of the most abundant oceanic dolphins in the temperate North Pacific (Leatherwood and Reeves 1983). Preliminary estimate of total population: 247,000-535,000 (Mangel, cited by Jefferson and Newcomer 1993). Hiramatsu (1991) estimated the population at 535,000 (95% confidence interval 394,000-738,000). Several 10,000s off California (see Jefferson and Newcomer 1993).

Travels in groups of up to several thousand; average group size about 100 (eastern Pacific) to 200 (western Pacific). Commonly associates with other cetaceans, especially the Pacific white-sided dolphin. Tends to avoid boats but may bowride. Fast swimmer.

Virtually nothing is known about reproduction or mating in this species.

Newborn are most commonly reported in winter or early spring; sexually mature at length of about 2 m (Leatherwood and Reeves 1983, Jefferson and Newcomer 1993). Based on samples caught in squid driftnets in the central North Pacific, about half of females were mature; among mature females, 16% were pregnant, 3% were pregnant and lactating, 33% were post partum, 24% were lactating (no recent pregnancy), 10% were resting, and 14% were of unknown condition; gestation period was 12.1-12.3 months; calving appeared to peak in July and August; average of sexual maturity was 10 years; the oldest male was 27 years old, the oldest female 42 years old; minimum calving interval was 2 years (Ferrero and Walker 1993).

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There is 1 barcode sequence available from BOLD and GenBank.   Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen.  Other sequences that do not yet meet barcode criteria may also be available.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1

Canada

Rounded National Status Rank: N4 - Apparently Secure

United States

Rounded National Status Rank: NU - Unrankable

Year Assessed

Assessor/s

Reviewer/s

Justification

History

• 1996
  Lower Risk/least concern
• 1994
  Insufficiently Known
  (Groombridge 1994)

The North Pacific squid driftnet fishery operated out of Japan, Korea, and Taiwan targets northern right whale dolphins. It is estimated that between 1985 and 1990 this fishery took 15,000 to 20,000 dolphins per year. The population has been depleted to anywhere from 24 to 73 percent of its pre-exploitation size. A moratorium on high seas driftnets could allow population levels to increase to previous levels. This species is listed on CITES Appendix II.

IUCN Red List of Threatened Species: least concern

Rounded Global Status Rank: G4 - Apparently Secure

Global Short Term Trend: Decline of 10 to >90%

Comments: Current abundance is 24 to 73 percent of the abundance in 1978, depending on which estimate of current population is assumed (Mangel 1993).

Population

Population Trend

Major Threats

Comments: This is the major marine mammal taken incidently in the extensive squid driftnet fishery that operates out of Japan, Korea, and Taiwan, which probably has greatly reduced the population in the western Pacific (take was estimated at 15,000-20,000 per year in the late 1980s); occasionally taken in salmon gillnet fisheries and in driftnets set for sharks and swordfish (Jefferson and Newcomer 1993).

Conservation Actions

The blubber from these animals is used to make oil.

Comments: Sometimes taken in Japanese harpoon fisheries (for human consumption) and Japanese and Russian purse-seine fisheries, but there is no fishery in which this species has been the main target (see Jefferson and Newcomer 1993). Generally has not done well in captivity.

Least Concern (LC)