Stejneger's Beaked Whale
About The Species
Stejneger's beaked whales, sometimes known as the "Bering Sea beaked whale" or "saber-toothed whale," are little known members of the beaked whale family (Ziphiidae). They receive their common and scientific name from Leonhard Stejneger, a naturalist and curator at the Smithsonian Institution, who first described the species from a single skull discovered on Bering Island in 1885. This species prefers the cold, temperate, and subarctic waters of the North Pacific Ocean and is generally found in deep, offshore waters on or beyond the continental slope.
There is little information on the abundance of Stejneger's beaked whales worldwide due to the rarity of sightings at sea. Overall, the beaked whale family is cryptic and skittish, and individual species lack any easily discernable physical characteristics, making it difficult to distinguish between them.
Although they face threats from entanglement in fishing gear, human-caused noise, and marine debris, Stejneger's beaked whales in the United States are not endangered or threatened. Like all marine mammals, they are protected under the Marine Mammal Protection Act.
NOAA Fisheries estimates population size for each stock of Stejneger's beaked whale in its stock assessment reports. A stock is a group of animals that occupy the same area and interbreed. There is little information on the abundance of this species worldwide due to the rarity of sightings at sea. Thus, data are insufficient to estimate population trends.
CITES Appendix II
- Throughout Its Range
- Throughout Its Range
As adults, Stejneger's beaked whales can reach lengths of about 18.7 feet and weigh up to 3,527 pounds. Females may be slightly larger than males. Males can be easily distinguished from females and juveniles by a pair of large, visible, forward-and-inward-pointing, tusk-like teeth that erupt from their arched lower jaw. Females and juveniles also have teeth, but they remain hidden beneath the gum tissue of the mouth, and their jawline is generally less curved.
Stejneger's beaked whales have a relatively medium-sized, round body with a small, wide-based, slightly hooked dorsal fin located about two-thirds down their back. They have a low-sloping, indistinct forehead (known as a melon). Their coloration varies from dark gray to brownish and black. A dark cap that extends across the top of the head from eye to eye, and the lower jaw is usually white or pale gray. The dark cap and light belly are more prominent on juveniles than adults. The ventral surface of the flukes of adults has a series of gray or white concentric lines, radiating from the midpoint of the trailing edge. The skin may be covered with linear and oval-shaped scars and other markings. Individuals, especially mature males, accumulate more scars and scratches with age. Mature males will battle each other for access to females.
Behavior and Diet
Stejneger's beaked whales are usually found individually or in small, tight social groups averaging between five and 15 individuals. These groups may contain animals of mixed sexes, ages, and life stages, or they can be segregated. Like most beaked whales, this species is difficult to approach and generally avoids vessels.
Stejneger's beaked whales usually make five to six shallow dives followed by a longer dive that lasts 10 to 15 minutes and may reach depths of 4,920 feet. While diving, they use suction to feed on small deep-water fish, tunicates, and cephalopods (e.g., squid).
Where They Live
Stejneger's beaked whales prefer the cold, temperate, and subarctic waters of the North Pacific Ocean. They are generally found in deep, offshore waters between 2,500 and 5,000 feet on or beyond the continental slope.
Stejneger's beaked whales have a distribution throughout the North Pacific that includes California, the Aleutian Islands, the southwest Bering Sea, Kamchatka, the Okhotsk Sea, and the Sea of Japan. There may be a resident population in the Sea of Japan and southern Okhotsk Sea. Strandings of this species have commonly occurred in the Aleutian Islands of Alaska and on the west coasts of Japan. Scientists speculate that Stejneger's beaked whales may migrate north in the summer. Information on their distribution mostly comes from stranding records.
Lifespan & Reproduction
Stejneger's beaked whales may become sexually mature when they reach about 14.8 feet in length. A sexually mature female will give birth to a single calf that is about 7.2 to 8 feet long and weighs about 175 pounds. The calving season is generally between spring and early autumn. The estimated lifespan of this species is at least 35 years.
Entanglement in Fishing Gear
Stejneger’s beaked whales can become entangled or captured in commercial fishing gear, particularly in driftnet and gillnet fisheries in the Sea of Japan and off the west coast of North America.
This species is hunted in a Japanese fishery that targets beaked whales.
Stejneger’s beaked whales are known to have ingested dangerous items such as plastic bags and string.
Deep-diving cetaceans like Stejneger’s beaked whales use sound to feed, communicate, and navigate in the ocean. Sound pollution threatens them by interrupting their normal behavior and driving them away from areas important to their survival. Anthropogenic loud noise such as active sonar or seismic activity can disorient or drive beaked whales to the surface too rapidly, leading to decompression sickness or death.
In the Spotlight
Like all marine mammals, the Stejneger’s beaked whale is protected under the Marine Mammal Protection Act. NOAA Fisheries is working to conserve this species to ensure populations remain stable.
Reducing Interactions with Fishing Gear
Stejneger’s beaked whales are caught as bycatch in fishing gear, leading to deaths and serious injuries, particularly in the driftnet and gillnet fisheries in the Sea of Japan and off the west coast of North America. NOAA Fisheries is committed to minimizing bycatch in U.S. fisheries to ensure these fisheries remain sustainable and to protect species such as the Stejneger’s beaked whale.
Addressing Ocean Noise
NOAA Fisheries is investigating all aspects of acoustic communication and hearing in marine animals, as well as the effects of sound on beaked whale behavior and hearing. In 2016, we issued technical guidance for assessing the effects of anthropogenic sound on marine mammal hearing.
Overseeing Marine Mammal Health and Stranding Response
We work with volunteer networks in all coastal states to respond to marine mammal strandings. When stranded animals are found alive, NOAA Fisheries and its partners assess the animal’s health and try to return it to the water. 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 identify strandings due 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 can have implications for human health and welfare.
Marine Mammal Unusual Mortality Events
Under the Marine Mammal Protection Act, an unusual mortality event (UME) 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.
Stejneger's beaked whales are protected under the MMPA.
Key Actions and Documents
Incidental Take Authorization: Lamont-Doherty Earth Observatory Marine Geophysical Survey in the Aleutian Islands
- Issued IHA (PDF, 18 pages)
- Application (PDF, 126 pages)
- Final Environmental Assessment
- Finding of No Significant Impact (PDF, 14 pages)
- Biological Opinion
- Public Comments
- References (PDF, 6 pages)
- Issued IHA (pdf, 19 pages)
- IHA Application (pdf, 124 pages)
- References (pdf, 23 pages)
- Environmental Assessment (pdf, 176 pages)
- FONSI (pdf, 14 pages)
- Biological Opinion (pdf, 208 pages)
- Draft EA (pdf, 168 pages)
- Monitoring Report (pdf, 94 pages)
Incidental Take Authorization: NOAA Fisheries NWFSC Fisheries and Ecosystem Research Activities in the Pacific Ocean
- Final Rule
- Notice of Proposed Rule
- Notice of Receipt of Application for LOA
- Notice of Availability of Draft Environmental Assessment
- Issued LOA (pdf, 12 pages)
- LOA Application (pdf, 206 pages)
- References cited (pdf, 25 pages)
- Programmatic EA (pdf, 415 pages)
- FONSI (pdf, 5 pages)
- Comments Received on Notice of Receipt (pdf, 6 pages)
- Biological Opinion (pdf, 324 pages)
- Comments Received on Proposed Rule (pdf, 7 pages)
- 2018 Monitoring Report (pdf, 3 pages)
- 2019 Monitoring Report (pdf, 4 pages)
- 2020 Monitoring Report (pdf, 1page)
Incidental Take Authorization: Lamont-Doherty Earth Observatory Marine Geophysical Survey in the North Pacific Ocean
- Issued IHA (pdf, 19 pages)
- IHA Application (pdf, 134 pages)
- References Cited (pdf, 39 pages)
- Public Comments (pdf, 29 pages)
- EA (pdf, 209 pages)
- FONSI (pdf, 14 pages)
- Biological Opinion (pdf, 220 pages)
- Monitoring Report (pdf, 93 pages)
Determining the size of Stejneger's beaked whale populations helps resource managers gauge the success of NOAA Fisheries’ conservation measures. Our scientists collect and present these data in annual stock assessment reports.
NOAA Fisheries conducts research cruises to collect information on beaked whale stocks, such as habit preferences and feeding ecology. These studies also help us estimate the abundance of beaked whales. Information from this research can be used in management actions to protect these animals.
Our research is also focused on acoustics—the physics of the properties of sound. We study the basic acoustic behavior of cetaceans and fish, mapping the acoustic environment and finding better ways to find cetaceans using acoustic technologies. Our acoustic research also assesses the degree to which human-caused activities are changing the underwater soundscape, how these changes may potentially impact marine animals in their acoustic habitat, and what measures can be taken to mitigate these potential impacts.