Mesoplodon mirus . True’s beaked whales are little known members of the beaked whale family, Ziphiidae. They can be found in deep, warm, temperate waters of the North Atlantic Ocean as well as at lea
Source: Species facts, status language, and imagery adapted from the NOAA Fisheries species profile (last updated 04/03/2026). Ocean City charter and Maryland
record notes are editorial orientation for OCEANCITY.MD readers. Always confirm current seasons, sizes, and
bag limits before you fish—rules change.
True’s beaked whales are little known members of the beaked whale family, Ziphiidae. They can be found in deep, warm, temperate waters of the North Atlantic Ocean as well as at least two other areas in the Southern Hemisphere. They receive their common name from Frederick W. True, a curator at the Smithsonian Institution, who described the species from an animal that stranded on a beach in North Carolina.
There is little information on the abundance of True’s beaked whales worldwide. The beaked whale family is cryptic and skittish and distinguishing between species in the field can be challenging.
Like all marine mammals, True’s beaked whales are protected under the Marine Mammal Protection Act and face threats from human-caused ocean noise. True’s beaked whales are considered “data deficient” by the International Union for Conservation of Nature’s list of threatened species, meaning that there is not enough information to assess their population status.
Maryland record catch
Confirm whether Maryland DNR publishes an Atlantic state-record category for True's Beaked Whale on the current sport-fish record board.
True's Beaked Whale is a protected marine species in U.S. waters. Do not harvest. This guide is biology and Ocean City context only—not a fishing target.
True's beaked whales have a relatively small- to medium-sized body with a moderately short beak, as well as a rounded, sloping forehead (known as a melon). They have a small, wide-based, slightly hooked dorsal fin located far down their back. Their coloration varies from gray to brown on the dorsal side with a paler ventral side. In the field, they are distinguished from Gervais’ beaked whales (which are similar in appearance) by the pale coloration across their melon and lack of a dark, defined dorsal stripe.
True’s beaked whales in the Southern Hemisphere have more white coloration on their back, tailstock, and underside than those in the Northern Hemisphere. Mature males may have linear scarring covering their body from battling other males for access to females during mating. This species is difficult to observe and identify at sea due to a low profile at the surface and a small, inconspicuous blow. Few have been seen alive at sea.
As adults, True's beaked whales can reach lengths of 15.5 to 17.5 feet and weigh from 2,200 to more than 3,000 pounds. Females may be slightly larger than males. Mature males can be distinguished from females and juveniles by a pair of teeth visible on the tip of their lower jaw. The mouthline is typically straight or slightly curved.
Behavior and Diet When observed, True's beaked whales are often alone or in small, closely associated groups averaging five to six animals. While diving, they use suction to feed on small fish and cephalopods (e.g., squid) in deep waters. This species has been known to breach and occasionally display surface active behaviors.
Even when dead, many species of beaked whales (especially those in the genus Mesoplodon) are difficult to distinguish from one another because they lack easily discernible or apparent physical characteristics. At sea, they are also challenging to observe and identify to the species level because of their cryptic, skittish behavior, low profile, and small, inconspicuous blow at the water’s surface. Therefore, much of the available characterization for beaked whales is to the genus level only.
Where They Live True's beaked whales prefer deep warm temperate waters of the North Atlantic Ocean as well as at least two other areas in the Southern Hemisphere (e.g., Indian Ocean). Their range, which is mostly known from strandings, includes areas off of Nova Scotia, Canada, Bay of Biscay, Ireland, Europe, the Azores, the Canary Islands, Bermuda, Florida, and the Bahamas in the Atlantic, as well as off the coasts of Brazil, Madagascar, South Africa, New Zealand, and southern Australia. It is unknown whether this species migrates or exhibits seasonal shifts in habitat use.
Appearance
When observed, True's beaked whales are often alone or in small, closely associated groups averaging five to six animals. While diving, they use suction to feed on small fish and cephalopods (e.g., squid) in deep waters. This species has been known to breach and occasionally display surface active behaviors.
Even when dead, many species of beaked whales (especially those in the genus Mesoplodon) are difficult to distinguish from one another because they lack easily discernible or apparent physical characteristics. At sea, they are also challenging to observe and identify to the species level because of their cryptic, skittish behavior, low profile, and small, inconspicuous blow at the water’s surface. Therefore, much of the available characterization for beaked whales is to the genus level only.
Where They Live True's beaked whales prefer deep warm temperate waters of the North Atlantic Ocean as well as at least two other areas in the Southern Hemisphere (e.g., Indian Ocean). Their range, which is mostly known from strandings, includes areas off of Nova Scotia, Canada, Bay of Biscay, Ireland, Europe, the Azores, the Canary Islands, Bermuda, Florida, and the Bahamas in the Atlantic, as well as off the coasts of Brazil, Madagascar, South Africa, New Zealand, and southern Australia. It is unknown whether this species migrates or exhibits seasonal shifts in habitat use.
Lifespan & Reproduction The lifespan of this species is unknown, and very little is known about their reproduction. Females generally give birth to a single calf that is about 6.5 to 8 feet long and weighs about 300 pounds.
Threats Ocean Noise Deep-diving cetaceans like True’s beaked whales use sound to feed, communicate, and navigate in the ocean. This species may be sensitive to underwater sounds and human-made noise. Sound pollution threatens them by interrupting their normal behavior and driving them away from areas important to their survival, such as breeding and feeding waters.
Scientific Classification Kingdom Animalia Phylum Chordata Class Mammalia Order Cetacea Family Ziphiidae Genus Mesoplodon Species mirus Last updated by NOAA Fisheries on 04/03/2026
Biology
True's beaked whales prefer deep warm temperate waters of the North Atlantic Ocean as well as at least two other areas in the Southern Hemisphere (e.g., Indian Ocean). Their range, which is mostly known from strandings, includes areas off of Nova Scotia, Canada, Bay of Biscay, Ireland, Europe, the Azores, the Canary Islands, Bermuda, Florida, and the Bahamas in the Atlantic, as well as off the coasts of Brazil, Madagascar, South Africa, New Zealand, and southern Australia. It is unknown whether this species migrates or exhibits seasonal shifts in habitat use.
Lifespan & Reproduction The lifespan of this species is unknown, and very little is known about their reproduction. Females generally give birth to a single calf that is about 6.5 to 8 feet long and weighs about 300 pounds.
Threats Ocean Noise Deep-diving cetaceans like True’s beaked whales use sound to feed, communicate, and navigate in the ocean. This species may be sensitive to underwater sounds and human-made noise. Sound pollution threatens them by interrupting their normal behavior and driving them away from areas important to their survival, such as breeding and feeding waters.
Scientific Classification Kingdom Animalia Phylum Chordata Class Mammalia Order Cetacea Family Ziphiidae Genus Mesoplodon Species mirus Last updated by NOAA Fisheries on 04/03/2026
Where they live
Range
True's beaked whales prefer deep warm temperate waters of the North Atlantic Ocean as well as at least two other areas in the Southern Hemisphere (e.g., Indian Ocean). Their range, which is mostly known from strandings, includes areas off of Nova Scotia, Canada, Bay of Biscay, Ireland, Europe, the Azores, the Canary Islands, Bermuda, Florida, and the Bahamas in the Atlantic, as well as off the coasts of Brazil, Madagascar, South Africa, New Zealand, and southern Australia. It is unknown whether this species migrates or exhibits seasonal shifts in habitat use.
Lifespan & Reproduction The lifespan of this species is unknown, and very little is known about their reproduction. Females generally give birth to a single calf that is about 6.5 to 8 feet long and weighs about 300 pounds.
Habitat
See the NOAA species profile for habitat detail for this entry.
Ocean City & Mid-Atlantic context
From Ocean City, Maryland, use this True's Beaked Whale profile as NOAA Mid-Atlantic directory context—not a promise you will meet the species on every charter.
True's Beaked Whale is protected. Do not harvest. Report unusual strandings or entanglements through official channels.
Source facts and imagery are adapted from the NOAA Fisheries species profile for True's Beaked Whale.
What charter to book from Ocean City
True's Beaked Whale is not a standard Ocean City charter harvest target. Use this profile for NOAA biology and Mid-Atlantic context only.
Not typical from OC
Bay guide — Not a typical Ocean City bay guide target for True's Beaked Whale.
Inshore charter — Not a typical Ocean City inshore charter target for True's Beaked Whale.
Casting / light tackle — Not a typical Ocean City casting / light tackle target for True's Beaked Whale.
Trolling charter — Not a typical Ocean City trolling charter target for True's Beaked Whale.
Nearshore wreck / bottom — Not a typical Ocean City nearshore wreck / bottom target for True's Beaked Whale.
Offshore charter — Not a typical Ocean City offshore charter target for True's Beaked Whale.
Head / party boat — Not a typical Ocean City head / party boat target for True's Beaked Whale.
Start with the charter directory trip-type picker so you compare boats inside the right
archetype—not a bay-guide quote against a canyon invoice.
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 True’s beaked whales 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.
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 technical guidance for assessing the effects of human-made sound on marine mammal hearing.
Regulatory History Like all marine mammals, True’s beaked whales are protected under the MMPA.
Harvest
See the NOAA wild-caught fishery section for landings and gear notes when published for this species.
Landings and management details matter most for the waters where True's Beaked Whale is actually fished—see the
NOAA species profile
.
