Morphology and Distinctive Features: Recognizing the North Atlantic Right Whale at Sea
The North Atlantic right whale (Eubalaena glacialis) stands out from all other large cetaceans in the North Atlantic by a combination of stable visual characteristics, usable from a boat deck or coastal promontory.
The Massive Body Without a Dorsal Fin
This is the first elimination criterion. No dorsal fin is visible on the back, unlike the fin whale (Balaenoptera physalus) or the humpback whale (Megaptera novaeangliae). The body is stocky, dark brown to black, with variable white ventral patches depending on the individual. The head represents about one third of the total length, which is disproportionate even from a distance. Adult size ranges from 13 to 17 meters for a weight of 40 to 80 tons.
Head Callosities
These are keratinized skin thickenings colonized by cyamids (parasitic crustaceans called whale lice) that give them a characteristic yellow-orange color. They are distributed on the rostrum, periorbital area, and lower lip. Their shape and position are unique to each individual, making them the most reliable photo-ID tool for the species. The New England Aquarium manages the reference catalog; images can be submitted via Happywhale to contribute to identification.
The V-Shaped Blow
The presence of two widely spaced blowholes produces a characteristic V-shaped blow, visible up to 5 km in calm weather. It is often the first sign detected from a promontory. No other North Atlantic species produces this blow profile as regularly.
Silhouette Compared to Other Mysticetes
The North Atlantic right whale is shorter and more massive than the fin whale, and differs from the Sei whale (Balaenoptera borealis) by the total absence of a dorsal fin and the presence of callosities. The strongly arched upper lip is visible in profile even from medium distance.
Feeding and Surface Behavior: Slow Skimming as a Behavioral Signature
The North Atlantic right whale is a surface filter feeder. Its feeding behavior is slow, predictable, and prolonged, making it both easy to observe and particularly vulnerable.
Continuous Skimming Technique and Ultra-Long Baleen Plates
It advances with its mouth partially open, at the surface or just below, continuously filtering large volumes of water through its baleen plates, which can reach 2.8 meters in length. This is the skimming technique (skim feeding in English). The slowness of this swim, between 1 and 3 knots, was precisely what made the animal so accessible to historical whalers.
Copepods as Almost Exclusive Prey
The North Atlantic right whale feeds almost exclusively on copepods, particularly Calanus finmarchicus. It can ingest up to 1,100 kg of zooplankton per day during intense feeding periods (MICS). This narrow dietary specialization makes it very sensitive to variations in copepod swarm distribution, especially under climate change effects.
Short Dives, Prolonged Surface Time
Dives rarely last more than 10 to 20 minutes. The animal thus spends a large part of its time at the surface, visible and exposed. An attentive observer can follow an individual skimming for several minutes uninterrupted, facilitating photo-ID but also increasing collision risk with ships.
Social Behaviors: SAG and Breaches
SAG (Surface Active Groups, surface active groups) gather several individuals in intense interactions, likely reproductive. These groups are noisy and visually spectacular. Breaches out of the water (breaching) are also documented, with their function still debated (communication, parasite removal, social play).
Seasonal Distribution and Observation Sites: Where and When to Look
The North Atlantic right whale follows a north-south migratory cycle between its summer feeding grounds and winter calving and breeding areas. Distribution has shifted over recent decades due to copepod swarm movements.
Bay of Fundy and Stellwagen Bank
Bay of Fundy (New Brunswick, Canada) and Stellwagen Bank (Massachusetts, USA) are the historical summer feeding grounds. Local operators and NOAA document concentrations of individuals from April to October. GREMM (Groupe de recherche et d'éducation sur les mammifères marins) publishes updated presence data each season for the entire Gulf of St. Lawrence.
Gulf of St. Lawrence
Since the mid-2010s, a growing proportion of individuals has moved to the Gulf of St. Lawrence in summer, where Calanus finmarchicus concentrations are now denser. This shift caught managers off guard: protective measures (speed reductions, fishery closures) were not yet in place during the first mass mortalities of 2017 (NOAA, Fisheries and Oceans Canada). Canadian authorities have since strengthened rules in this area.
Wintering and Calving Grounds in Florida-Georgia
From December to March, pregnant females migrate to the warm coastal waters of Florida and Georgia to calve. These areas are under close NOAA surveillance. Observations are possible but strictly regulated, as uncontrolled human presence can disrupt births.
Why the Species is Virtually Absent from European Waters
Historical sources attest to past presence in the Bay of Biscay and off Iberian coasts, exploited by Basque whalers from the 12th century. No confirmed sightings have been recorded in these waters for decades. The population is now confined to the Northwest Atlantic. A European traveler wishing to see this species must go to North America.
Two Centuries of Whaling and a Decline That Has Never Truly Reversed
The history of the North Atlantic right whale is one of a species first exploited to collapse by humans, then protected too late and too partially for true recovery.
Why Whalers Called It the "Right Whale"
Slow, floating after death thanks to its thick blubber layer, rich in marketable oil and baleen: the North Atlantic right whale had all the qualities sought by whalers. Basques exploited it in the Bay of Biscay from the 12th century, then in the Northwest Atlantic from the 16th century. Its slow, predictable surface skimming behavior made it particularly accessible to oar-powered boats.
19th-Century Collapse and 1935 Protection
Intensive 19th-century whaling reduced the population to a few dozen individuals. International protection was granted in 1935 by the League of Nations, but populations were already so low that recovery has been extremely slow.
Partial Rise Until 2010, Then New Decline
The population gradually reached about 500 individuals around 2010, before starting a new decline. From 2017, a series of abnormally high mortalities, especially in the Gulf of St. Lawrence, accelerated the drop. Recent estimates place the population between 356 and 370 individuals (NOAA, New England Aquarium, 2022-2024).
The Current Number and Its Demographic Meaning
The raw number hides an even more worrying reality. Fewer than 100 females are of reproductive age. The inter-birth interval is long, around 3 to 5 years. Each lost breeding female thus represents an irreplaceable loss of reproductive capacity in the short term. The current anthropogenic mortality rate exceeds what the species' demography can absorb (NOAA, 2023).
Current Threats: Collisions and Entanglements Dominate the Mortality Table
A multi-agency study published in 2019 (Sharp et al., IFAW) established that nearly 90% of deaths whose cause could be determined between 2003 and 2018 were directly anthropogenic. Two causes dominate.
Collisions with Ships
The North Atlantic right whale's slow skimming and prolonged surface time place it directly in commercial shipping lanes. Fatal collisions mainly occur at speeds over 10 knots. NOAA and Fisheries and Oceans Canada have implemented mandatory speed reduction zones on the busiest routes, but enforcement is uneven and geographic coverage insufficient given the species' recent shifts to the Gulf of St. Lawrence.
Entanglement in Fishing Gear
Vertical ropes from lobster and crab traps are the main entanglement source. An animal caught in this gear can survive for months, dragging equipment that exhausts, starves, and causes deep injuries. Field studies show most individuals bear entanglement scars (New England Aquarium, photo-ID catalog). Ropeless gear is under development and gradual deployment, but adoption remains limited.
Climate Change and Copepod Shifts
Warming waters shift Calanus finmarchicus concentrations northward, pushing right whales into less protected, more trafficked areas. This shift makes spatial management measures harder to calibrate (NOAA, 2022).
Recent Regulatory Initiatives
The US and Canada have strengthened regulations since 2017: seasonal fishery closures, reporting obligations, maritime route deviations in certain corridors. These measures have reduced some risks, but experts agree their implementation remains insufficient to reverse the current demographic trend (Whale and Dolphin Conservation, 2023).
Responsibly Observing the North Atlantic Right Whale: Distances, Regulations, and Ethics
For a species whose total population fits in a small village, every uncontrolled human interaction has real statistical weight. Responsible approach is not optional.
US and Canadian Regulations
In the United States, regulations require a minimum distance of 500 yards (about 450 m) for any vessel or person. This is one of the strictest cetacean protection distances worldwide. In Canada, rules vary by zone and season, with enhanced measures in the Gulf of St. Lawrence. These distances apply to all, including kayakers and swimmers.
Choose a Certified Operator
I systematically recommend operators adhering to the High Quality Whale Watching (HQWW) charter or equivalent national program. These operators train their crews, respect legal distances, and contribute to scientific monitoring programs. Certified operators generally publish presence data in partnership with organizations like GREMM or NOAA.
Contribute to Citizen Science
Photos of head callosities enable individual identification. Any clear image can be submitted to Happywhale or directly to the New England Aquarium, which manages the species' reference photo-ID catalog. Any sighting report must also be sent to NOAA (US) or Fisheries and Oceans Canada (DFO) depending on the area. These data feed real-time management models.
What Never to Do
Never approach head-on an animal skimming: it forces it to deviate from its feeding path and can trigger an energy-costly flight response. Never leave the engine running in close proximity. Never position between a mother and her calf. For a species with fewer than 400 individuals, these rules are not symbolic.
North Atlantic, Southern, and North Pacific Right Whales: Three Species, Three Fates
The genus Eubalaena includes three species, morphologically very similar but with radically different demographic trajectories. A table allows direct comparison.
| Species | Common Name | Estimated Population | IUCN Status | Main Areas of Presence |
|---|---|---|---|---|
| Eubalaena glacialis | North Atlantic right whale | 356-370 individuals (NOAA, 2024) | Critically Endangered | Northwest Atlantic (Canada, USA) |
| Eubalaena australis | Southern right whale | ~10,000 individuals (IUCN, 2022) | Least Concern | Southern Hemisphere (Argentina, South Africa, Australia, New Zealand) |
| Eubalaena japonica | North Pacific right whale | ~30-40 individuals (IUCN, 2022) | Critically Endangered | North Pacific (Sea of Okhotsk, Japanese coasts) |
Why the Southern Population is Doing Better
The southern right whale (Eubalaena australis) benefited from historically less intense whaling pressure in some Southern Hemisphere areas, and its feeding and calving grounds overlap less with the busiest commercial shipping routes. Its population is growing moderately, making it a reference case for biologists studying the potential natural recovery trajectory of the North Atlantic population.
North Pacific Right Whale: An Even More Critical Situation
The North Pacific right whale (Eubalaena japonica) is probably the world's most threatened large cetacean species, with an estimated population of only 30 to 40 individuals (IUCN, 2022). Sightings are extremely rare. Field operators and Japanese and Russian researchers document sporadic appearances in the Sea of Okhotsk, but the long-term viability of this population is seriously questioned by specialist demographers.
Frequently asked
How many North Atlantic right whales remain in the world?
Recent estimates place the population between 356 and 370 individuals (NOAA, New England Aquarium, 2022-2024). Among them, fewer than a hundred are females of reproductive age, making each birth and each death critical for the species' survival. The current anthropogenic mortality rate exceeds what the species' demography can absorb.
How to recognize a North Atlantic right whale at sea?
Three cumulative criteria allow identification: total absence of dorsal fin, yellow-orange callosities on the head (rostrum, periorbital area, lower lip), and the V-shaped blow from two widely spaced blowholes. The body is stocky, dark brown to black, sometimes with white ventral patches. The head represents about one third of the total length, visible even from a distance.
Where to observe the North Atlantic right whale?
Main sites are Bay of Fundy (New Brunswick, Canada) in summer, Stellwagen Bank (Massachusetts, USA) in spring, and the Gulf of St. Lawrence. Local operators and GREMM publish updated presence data each season. Wintering areas are off Florida and Georgia, but observations there are strictly regulated.
Why is the North Atlantic right whale so threatened?
Two causes dominate: ship collisions and entanglements in fishing gear. A 2019 multi-agency study (Sharp et al., IFAW) established that nearly 90% of deaths whose cause could be determined between 2003 and 2018 were directly anthropogenic. Climate change worsens the situation by shifting prey to less protected areas.
Does the North Atlantic right whale exist in Europe?
The population is now virtually absent from European waters. Historical sources attest to past presence in the Bay of Biscay and off Iberian coasts, exploited by Basque whalers from the 12th century. No confirmed sightings have been recorded there for decades. The population is now confined to the Northwest Atlantic.
What is the difference between North Atlantic right whale and southern right whale?
They are two distinct species. Eubalaena australis (southern right whale) numbers about 10,000 individuals with IUCN status "Least Concern". Eubalaena glacialis (North Atlantic right whale) is "Critically Endangered" with fewer than 400 individuals. Morphologically very similar, they differ mainly in distribution and population dynamics.
Can amateurs contribute to North Atlantic right whale research?
Yes. Photos of head callosities enable individual identification via photo-ID. Images can be submitted to Happywhale or directly to the New England Aquarium, which manages the species' reference catalog. Any sighting report must also be sent to NOAA (US) or Fisheries and Oceans Canada (DFO) depending on the area.
What does the North Atlantic right whale eat?
Mainly copepods, particularly Calanus finmarchicus. It feeds by continuous skimming at or just below the surface, mouth partially open, filtering water through its long baleen plates that can reach 2.8 meters. It can ingest up to 1,100 kg of zooplankton per day during intense feeding periods (MICS).
What minimum distance to maintain from a North Atlantic right whale?
US regulations require a minimum distance of 500 yards (about 450 m) for vessels and people, among the strictest worldwide for a cetacean. In Canada, enhanced measures apply in the Gulf of St. Lawrence by season. These distances are legally binding and apply to all users, including small craft.