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Sowerby's Beaked Whale

Sowerby's Beaked Whale

Mesoplodon bidens

640x427-sowerbys-beaked-whale.jpg

Protected Status

CITES Appendix II
Throughout Its Range
MMPA Protected
Throughout Its Range

Quick Facts

Weight
2,200 to 2,900 pounds
Lifespan
Unknown
Length
14.5 to 21 feet
Threats
Commercial whaling, Entanglement in fishing gear, Ocean noise
Region
New England/Mid-Atlantic
See Regulatory Actions
Photo taken from behind showing a Sowerby's beaked whale peaking out of blue-green water. Sowerby's beaked whale. Credit: NOAA Fisheries.

Sowerby's beaked whale. Credit: NOAA Fisheries.

About the Species

Sowerby's beaked whales, sometimes known as the "North Atlantic beaked whale," are little known members of the beaked whale family, Ziphiidae. The first beaked whale to be discovered, this species prefers the deep, cold, temperate and subarctic waters throughout the North Atlantic Ocean, but has also been reported near the ice pack. Their scientific name, bidens, is derived from the Latin words bi for "two" and dens for "teeth" and refers to the pair of visible teeth that erupt from the lower jaw of mature males.  

The beaked whale family is cryptic and skittish. Due to the rarity of sightings at sea, there is little information on the abundance of Sowerby’s beaked whales worldwide. 

Like all marine mammals, Sowerby’s beaked whales are protected under the Marine Mammal Protection Act. They face threats from entanglement in fishing gear and human-caused noise.

Population Status

NOAA Fisheries estimates population size for Sowerby’s beaked whales 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. Thus, data are insufficient to estimate population trends.

Protected Status

CITES Appendix II

  • Throughout Its Range

MMPA Protected

  • Throughout Its Range

Appearance

As adults, Sowerby's beaked whales can reach estimated lengths of 14.5 to 21 feet and weigh 2,200 to 2,900 pounds. Males, which are generally larger, can be distinguished from females and juveniles by a pair of visible teeth that erupt from their slightly arched lower jaw. Females and juveniles also have teeth, but they remain hidden beneath the gum tissue, and their jawline is straight. 

Sowerby's beaked whales have a small- to medium-sized body with a very long, slender beak relative to other beaked whales, as well as a bulge on the forehead area. The beak often emerges at a steep angle when surfacing. They have a small, wide-based, slightly hooked dorsal fin located about two-thirds down their back. Most of their body is charcoal gray with a pale underside, and calves are generally darker than adults. The lower jaw is usually light gray or white. This species has less visible scarring than most other beaked whale species. 

Behavior and Diet

Sowerby's beaked whales are usually found individually or in small, closely associated groups averaging between three and 10 individuals. Regular dives range from 10 to 15 minutes, but dives of at least 28 minutes and reaching depths up to 4,920 feet have been recorded. While diving, they use suction to feed on small, deep-sea fish and cephalopods (e.g., squid) in deep waters. When surfacing, this species often lifts its head up out of the water at a 45-degree angle.

Many species of beaked whales (especially those in the genus Mesoplodon) are very difficult to distinguish from one another (even when dead) because they lack easily discernible or apparent physical characteristics. At sea, they are challenging to observe and identify to the species level because of their cryptic, skittish behavior; low profile; and a small, inconspicuous blow at the water’s surface. Therefore, much of the available characterization for beaked whales is to the genus level only, and there is relatively little information about most individual species. 

Where They Live

Sowerby's beaked whales prefer the deep, cold temperate and subarctic waters off the continental shelf edge of the North Atlantic Ocean but have also been reported near the ice pack. They are distributed throughout the North Atlantic Ocean (30° to 71° North), ranging from the Norwegian Sea, Labrador Sea, Iceland, and Baltic Sea to the north, and waters off the northeast United States, Madeira, and the Canaries to the south.  

Sowerby’s beaked whales may be  more common in the eastern than the western North Atlantic Ocean. However, they rarely occur in the Mediterranean Sea. Strandings have occurred in Florida and Italy, but these areas are considered outside their normal range. Their distribution may vary depending on the movements of oceanographic currents. It is unknown whether they undertake seasonal movements or migrations. 

Lifespan & Reproduction

Sowerby's beaked whales may reach sexual maturity at about age 7, and their breeding season may be from late winter to spring. A sexually mature female will give birth to a single newborn calf that is about 8 to 9 feet long and weighs about 375 pounds. The estimated lifespan of this species is unknown.

Threats

Entanglement in Fishing Gear

Sowerby’s beaked whales have become entangled or captured in commercial fishing gear, such as driftnets and gillnets, off the U.S. Atlantic and Canadian coasts.

Ocean Noise

Deep-diving cetaceans like Sowerby's beaked whales rely on 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.

Scientific Classification

Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Cetacea
Family Ziphiidae
Genus Mesoplodon
Species bidens

What We Do

Conservation & Management

All Sowerby’s beaked whales are protected under the MMPA. We protect this species by:

  • Reducing interactions with commercial and recreational fishing gear
  • Implementing requirements to reduce serious injuries and mortalities
  • Minimizing the effects of vessel disturbance, noise, and other human impacts
  • Educating the public about the threats beaked whales face
Learn more about our conservation efforts

Science

Our research projects have helped us better understand Sowerby’s beaked whales and the challenges they face. Our work includes: 

  • Stock assessments
  • Acoustic monitoring
  • Shipboard surveys
Learn more about our research

How You Can Help

Keep your distance.

Keep Your Distance

Be responsible when viewing marine life in the wild. Observe all large whales from a safe distance of at least 100 yards and limit your time spent observing to 30 minutes or less.

Learn more about our marine life viewing guidelines >

Marine Life In Distress

Report Marine Life in Distress

Report a sick, injured, entangled, stranded, or dead animal to make sure professional responders and scientists know about it and can take appropriate action. Numerous organizations around the country are trained and ready to respond. Never approach or try to save an injured or entangled animal yourself—it can be dangerous to both the animal and you.

Learn who you should contact when you encounter a stranded or injured marine animal >

Report a Violation

Report a Violation

Call the NOAA Fisheries Enforcement Hotline at (800) 853-1964 to report a federal marine resource violation. This hotline is available 24 hours a day, 7 days a week for anyone in the United States.

You may also contact your closest NOAA Office of Law Enforcement field office during regular business hours.

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Related Species

In the Spotlight

Management Overview

Sowerby's beaked whales, like all marine mammals, are protected under the Marine Mammal Protection Act.

Conservation Efforts

Reducing Interactions with Fishing Gear 

Sowerby’s beaked whales are caught as bycatch in fishing gear, such as driftnets and gillnets, off the U.S. Atlantic coast. NOAA Fisheries is committed to minimizing bycatch in U.S. fisheries to ensure that fisheries remain sustainable and to protect species such as the Sowerby’s beaked whale.

Learn more about bycatch and fisheries interactions

Overseeing Marine Mammal Health and Stranding Response

We work with volunteer networks in all coastal states to respond to marine mammal strandings including all whales. 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.

Learn more about the Marine Mammal Health and Stranding Response Program

Marine Mammal Unusual Mortality Events

Sowerby’s beaked whales have been part of a declared unusual mortality event in the past. 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.

Get information on active and past UMEs

Get an overview of marine mammal UMEs

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. For example, the use of at least some types of shipboard echosounders decreases the acoustic detection rates of multiple species of beaked whales, indicating that they change their behavior when they hear these echosounders. In 2018, we revised the technical guidance for assessing the effects of anthropogenic sound on marine mammal hearing.

Learn more about ocean noise

Regulatory History

Sowerby’s beaked whales are protected under the MMPA.

Key Actions and Documents

Incidental Take

Incidental Take Authorization: Scripps Institution of Oceanography Low-energy Marine Geophysical Survey in the Northwest Atlantic Ocean

NOAA Fisheries issued an incidental harassment authorization (IHA) to Scripps Institution of Oceanography to incidentally harass, by Level B and Level A harassment, marine mammals during a low-energy marine geophysical survey in the Northwest Atlantic…
Notice
,
New England/Mid-Atlantic
Published
06/15/2018

Incidental Take Authorization: United States Geological Survey Geophysical Survey in the Northwest Atlantic Ocean

NOAA Fisheries issued an incidental harassment authorization (IHA) to USGS to incidentally harass, by Level B harassment only, marine mammals during geophysical survey activities associated with a the USGS’s Mid-Atlantic Resource Imaging Experiment …
Notice
,
New England/Mid-Atlantic
Published
08/10/2018

Incidental Take Authorization: U.S. Navy Atlantic Fleet Training and Testing (AFTT) along Atlantic and Gulf Coasts (2018-2025)

NOAA Fisheries has issued regulations pursuant to the Marine Mammal Protection Act (MMPA) to govern the taking of marine mammals incidental to the training and testing activities conducted in the Atlantic Fleet Training and Testing (AFTT) Study Area…
Proposed Rule
,
New England/Mid-Atlantic
Southeast
Foreign
Effective
11/14/2018

Incidental Take Authorization: U.S. Navy Atlantic Fleet Training and Testing (2013 -2018)

NOAA Fisheries issued regulations under the MMPA to govern the unintentional taking of marine mammals incidental to training and testing activities conducted in the Atlantic Fleet Training and Testing (AFTT) Study Area from November 2013 through…
Final Rule
,
New England/Mid-Atlantic
Southeast
Foreign
Published
12/04/2013

More Information

Science Overview

NOAA Fisheries conducts a variety of research on the biology, behavior, and ecology of Sowerby’s beaked whales. The results of this research are used to inform management decisions and enhance protection efforts for this species.

Stock Assessments

Determining the size of Sowerby’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.

Shipboard Studies

NOAA Fisheries conducts research cruises to collect information on beaked whale stocks, including distribution, habitat 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.

Acoustic Science

Our research is also focused on acoustics—using underwater sound to learn more about species. We study the basic acoustic behavior of cetaceans and fish, mapping the acoustic environment and finding better ways to study cetaceans using passive acoustic technologies. For example, we tow hydrophones behind ships to acoustically detect and locate Sowerby’s beaked whales during surveys. We also use archival bottom-mounted recorders to monitor long-term occurrence of the species at specific recording sites. 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, and what measures can be taken to mitigate these potential impacts.

Learn more about acoustics science

Research & Data

Passive Acoustic Cetacean Map

This mapping tool shows when and where specific whale, dolphin, and other…
June 03, 2021 - Query Tool ,
New England/Mid-Atlantic
This illustration shows the variety of technologies that NOAA Fisheries researchers use to record underwater sounds and study marine animals. The seascape shows bottom- mounted and drifting acoustic recorders, underwater autonomous vehicles, Atlantic cod and humpback whale with tags, and instruments deployed from a NOAA ship and small boat. Colored circles show a zoomed-in view of the instruments and indicate the type of data collected: green for real-time data, orange for archival data, and blue for active
View More

More Information

Data & Maps

Data

Passive Acoustic Cetacean Map

This mapping tool shows when and where specific whale, dolphin, and other cetacean species were…

New England/Mid-Atlantic
More Data and Maps