Temporal range: Early Pleistocene – Recent
|Adult blue whale |
|Size compared to an average human|
|Blue whale range (in blue)|
The blue whale (Balaenoptera musculus) is a marine mammal belonging to the baleen whale parvorder, Mysticeti. At up to 29.9 meters (98 ft) in length and with a maximum recorded weight of 173 tonnes (190 short tons), it is the largest animal known to have ever existed.
Long and slender, the blue whale's body can be various shades of bluish-gray dorsally and somewhat lighter underneath. There are at least three distinct subspecies: B. m. musculus of the North Atlantic and North Pacific, B. m. intermedia of the Southern Ocean and B. m. brevicauda (also known as the pygmy blue whale) found in the Indian Ocean and South Pacific Ocean. B. m. indica, found in the Indian Ocean, may be another subspecies. As with other baleen whales, its diet consists almost exclusively of small crustaceans known as krill.
Blue whales were abundant in nearly all the oceans on Earth until the beginning of the twentieth century. For over a century, they were hunted almost to extinction by whaling until protected by the international community in 1966. A 2002 report estimated there were 5,000 to 12,000 blue whales worldwide, in at least five populations. The IUCN estimates that there are probably between 10,000 and 25,000 blue whales worldwide today. Before whaling, the largest population was in the Antarctic, numbering approximately 239,000 (range 202,000 to 311,000). There remain only much smaller (around 2,000) concentrations in each of the eastern North Pacific, Antarctic, and Indian Ocean populations. There are two more groups in the North Atlantic, and at least two in the Southern Hemisphere. The Eastern North Pacific blue whale population had rebounded by 2014 to nearly its pre-hunting population.
- 1 Taxonomy
- 2 Description
- 3 Behavior
- 4 Population and whaling
- 5 Popularity
- 6 Museums
- 7 Whale-watching
- 8 See also
- 9 References
- 10 Further reading
- 11 External links
Blue whales are rorquals (family Balaenopteridae), a family that includes the humpback whale, the fin whale, Bryde's whale, the sei whale, and the minke whale. The family Balaenopteridae is believed to have diverged from the other families of the suborder Mysticeti as long ago as the middle Oligocene (28 Ma ago). The blue whale lineage diverged from the other rorquals during the Miocene, between 7.5 and 10.5 million years ago. However, gene flow between the species appears to have continued beyond that date. The blue whale has the greatest genetic diversity of any baleen whale, and a higher than average diversity among mammals. The earliest known anatomically modern blue whale is a partial skull fossil found in southern Italy, dating to between 1.25 and 1.49 million years ago. The whale is estimated to have been between 23.4 and 26.1 meters (76.8 to 85.6 ft) long in life. This finding overturns a previous hypothesis that baleen whales rapidly reached their modern sizes at 300,000 years ago, with the most likely date being a more gradual change around 3.6 million years ago, possibly earlier.
The blue whale is usually classified as one of eight species in the genus Balaenoptera; one authority places it in a separate monotypic genus, Sibbaldus, but this is not accepted elsewhere. DNA sequencing analysis indicates that the blue whale is phylogenetically closer to the sei whale (Balaenoptera borealis) and Bryde's whale (Balaenoptera brydei) than to other Balaenoptera species, and closer to the humpback whale (Megaptera) and the gray whale (Eschrichtius) than to the minke whales (Balaenoptera acutorostrata and Balaenoptera bonaerensis).
There have been at least 11 documented cases of blue whale-fin whale hybrid adults in the wild. Arnason and Gullberg describe the genetic distance between a blue and a fin as about the same as that between a human and a gorilla. Researchers working off Fiji believe they photographed a hybrid humpback-blue whale including the discovery through DNA analysis from a meat sample found in a Japanese market.
The first published description of the blue whale comes from Robert Sibbald's Phalainologia Nova (1694). In September 1692, Sibbald found a blue whale that had stranded in the Firth of Forth – a male 24 m (78 ft) long – that had "black, horny plates" and "two large apertures approaching a pyramid in shape".
The specific name musculus is Latin and could mean "muscle", but it can also be interpreted as "little mouse". Carl Linnaeus, who named the species in his seminal Systema Naturae of 1758, would have known this and may have intended the ironic double meaning. Herman Melville called this species "sulphur-bottom" in his novel Moby-Dick (1851) due to an orange-brown or yellow tinge on the underparts from diatom films on the skin. Other common names for the blue whale have included "Sibbald's rorqual" (after Sibbald, who first described the species), the "great blue whale" and the "great northern rorqual". These names have now fallen into disuse. The first known usage of the term "blue whale" was in Melville's Moby-Dick, which only mentions it in passing and does not specifically attribute it to the species in question. The name was really derived from the Norwegian blåhval, coined by Svend Foyn shortly after he had perfected the harpoon gun; the Norwegian scientist G. O. Sars adopted it as the Norwegian common name in 1874.
Authorities classify the species into three or four subspecies: B. m. musculus, the northern blue whale consisting of the North Atlantic and North Pacific populations, B. m. intermedia, the southern blue whale of the Southern Ocean, B. m. brevicauda, the pygmy blue whale found in the Indian Ocean and South Pacific, and the more problematic B. m. indica, the great Indian rorqual, which is also found in the Indian Ocean and, although described earlier, may be the same subspecies as B. m. brevicauda.
The pygmy blue whale formed from a founder group of Antarctic blue whales about 20,000 years ago, around the Last Glacial Maximum. This is likely because blue whales were driven north by expanding ice, and some have stayed there ever since. The pygmy blue whale's evolutionarily recent origins cause it to have a relatively low genetic diversity.
The blue whale has a long tapering body that appears stretched in comparison with the stockier build of other whales. The head is flat, U-shaped and has a prominent ridge running from the blowhole to the top of the upper lip. The front part of the mouth is thick with baleen plates; around 300 plates, each around one meter (3.3 feet) long, hang from the upper jaw, running 0.5 m (20 in) back into the mouth. Between 70 and 118 grooves (called ventral pleats) run along the throat parallel to the body length. These pleats assist with evacuating water from the mouth after lunge feeding (see feeding below).
The dorsal fin is small; its height averages about 28 centimeters (11 in), and usually ranges between 20 and 40 cm (7.9 and 15.7 in), though it can be as small as 8 cm (3.1 in) or as large as 70 cm (28 in). It is visible only briefly during the dive sequence. Located around three-quarters of the way along the length of the body, it varies in shape from one individual to another; some only have a barely perceptible lump, but others may have prominent and falcate (sickle-shaped) dorsals. When surfacing to breathe, the blue whale raises its shoulder and blowhole out of the water to a greater extent than other large whales, such as the fin or sei whales. Observers can use this trait to differentiate between species at sea. Some blue whales in the North Atlantic and North Pacific raise their tail fluke when diving. When breathing, the whale emits a vertical single-column spout, typically 9 meters (30 ft) high, but reaching up to 12 meters (39 ft). Its lung capacity is 5,000 liters (1,300 U.S. gal). Blue whales have twin blowholes shielded by a large splashguard.
The flippers are 3–4 meters (9.8–13.1 ft) long. The upper sides are gray with a thin white border; the lower sides are white. The head and tail fluke are generally uniformly gray. The whale's upper parts, and sometimes the flippers, are usually mottled. The degree of mottling varies substantially from individual to individual. Some may have a uniform slate-gray color, but others demonstrate a considerable variation of dark blues, grays and blacks, all tightly mottled.
Blue whales can reach speeds of 50 kilometers per hour (31 mph) over short bursts, usually when interacting with other whales, but 20 kilometers per hour (12 mph) is a more typical traveling speed. Satellite telemetry of Australian pygmy blue whales migrating to Indonesia has shown that they cover between 0.09 and 455.8 kilometers (0.056 and 283.221 miles) per day. When feeding, they slow down to 5 kilometers per hour (3.1 mph).
Blue whales most commonly live alone or with one other individual. It is not known how long traveling pairs stay together. In locations where there is a high concentration of food, as many as 50 blue whales have been seen scattered over a small area. They do not form the large, close-knit groups seen in other baleen species.
Blue whales are difficult to weigh because of their size. They were never weighed whole, but cut into blocks 0.5–0.6 meters (1.6–2.0 ft) across and weighed by parts. This caused a considerable loss of blood and body fluids, estimated to be about 6% of the total weight. As a whole, blue whales from the Northern Atlantic and Pacific are smaller on average than those from Antarctic waters. Adult weights typically range from 45–136 tonnes (50–150 short tons). There is some uncertainty about the biggest blue whale ever found, as most data came from blue whales killed in Antarctic waters during the first half of the twentieth century, which were collected by whalers not well-versed in standard zoological measurement techniques. The standard measuring technique is to measure in a straight line from the upper jaw to the notch in the tail flukes. This came about because the edges of the tail flukes were typically cut off, and the lower jaw often falls open upon death. Many of the larger whales in the whaling records (especially those over 100 ft (30.5 m)) were probably measured incorrectly or even deliberately exaggerated. The heaviest weight ever reported was 173 tonnes (190 short tons); for a southern hemisphere female in 1947, it is likely that the largest blue whales would have weighed over 200 short tons (181 t). The longest whales ever recorded were two females measuring 33.6 and 33.3 meters (110 and 109 ft), but in neither of these cases was the piecemeal weight gathered. Possibly the largest recorded male was killed near the South Shetland Islands in 1926 and was measured at 31.7 m (104 ft).
Females are generally a few feet longer than males. However, males may be slightly heavier on average than females of the same length, owing to heavier muscles and bones. Verified measurements rarely exceed 28 meters (92 ft). The longest measured by Macintosh and Wheeler (1929) was a female 28.50 meters (93.5 ft), while the largest male was 26.45 meters (86.8 ft); one of the same authors later found a male of 26.65 meters (87.4 ft) and stated that those lengths may be exceeded. The longest whale measured by scientists was 29.9 meters (98 ft) long. Lieut. Quentin R. Walsh, USCG, while acting as whaling inspector of the factory ship Ulysses, verified the measurement of a 29.9 m (98 ft) pregnant blue whale caught in the Antarctic in the 1937–38 season. A 26.8 meters (88 ft) male was verified by Japanese scientists in the 1947–48 whaling season. The longest reported in the North Pacific was a 27.1 meters (89 ft) female taken by Japanese whalers in 1959, and the longest reported in the North Atlantic was a 28 meters (92 ft) female caught in the Davis Strait. The average weight of the longest scientifically verified specimens (29.9 meters (98 ft)) would be calculated to be 176.5 tonnes (194.6 tons), varying from 141 tonnes (155.4 tons) to 211.5 tonnes (233.1 tons) depending on fat condition. One study found that a hypothetical 33 meters (108 ft) blue whale would be too large to exist in real life, due to metabolic and energy constraints.
Due to its large size, several organs of the blue whale are the largest in the animal kingdom. A blue whale's tongue weighs around 2.7 tonnes (3.0 short tons) and, when fully expanded, its mouth is large enough to hold up to 90 tonnes (99 short tons) of food and water. Despite the size of its mouth, the dimensions of its throat are such that a blue whale cannot swallow an object wider than a beach ball. The heart of an average sized blue whale weighs 400 pounds (180 kg) and is the largest known in any animal. During the first seven months of its life, a blue whale calf drinks approximately 380 liters (100 U.S. gal) of milk every day. Blue whale calves gain weight quickly, as much as 90 kilograms (200 lb) every 24 hours. Even at birth, they weigh up to 2,700 kilograms (5,950 lb)—the same as a fully grown hippopotamus. Blue whales have proportionally small brains, only about 6.92 kilograms (15.26 lb), about 0.007% of its body weight, although with a highly convoluted cerebral cortex. The blue whale penis is the largest penis of any living organism and also set the Guinness World Record as the longest of any animal's. The reported average length varies but is usually mentioned to have an average length of 2.4 to 3.0 m (8 to 10 ft).
Today, the blue whale is renowned for being the largest animal ever to have lived. In part because of its legendary status, many misconceptions still exist. For example, its size is often exaggerated. Many popular sources give the maximum length as 110 feet (34 meters) or more. While such lengths were reported in the whaling records, they were not scientifically verified and were probably exaggerated. Virtually all books and articles that mention the blue whale claim that it can reach 100 feet (30 meters). This is probably true (the largest verified specimen was 30 meters, 98 feet) but is highly misleading as the average size is much smaller.
Blue whales feed almost exclusively on krill, though they also take small numbers of copepods. The species of this zooplankton eaten by blue whales varies from ocean to ocean. In the North Atlantic, Meganyctiphanes norvegica, Thysanoessa raschii, Thysanoessa inermis and Thysanoessa longicaudata are the usual food; in the North Pacific, Euphausia pacifica, Thysanoessa inermis, Thysanoessa longipes, Thysanoessa spinifera, Nyctiphanes simplex and Nematoscelis megalops; and in the Southern Hemisphere, Euphausia superba, Euphausia crystallorophias, Euphausia valentini, and Nyctiphanes australis.
An adult blue whale can eat up to 40 million krill in a day. The whales always feed in the areas with the highest concentration of krill, sometimes eating up to 3,600 kilograms (7,900 lb) of krill in a single day. The daily energy requirement of an adult blue whale is in the region of 1.5 million kilocalories (6.3 GJ). Their feeding habits are seasonal. Blue whales gorge on krill in the rich waters of the Antarctic before migrating to their breeding grounds in the warmer, less-rich waters nearer the equator. The blue whale can take in up to 90 times as much energy as it expends, allowing it to build up considerable energy reserves.
Because krill move, blue whales typically feed at depths of more than 100 meters (330 ft) during the day and only surface-feed at night. Dive times are typically 10 minutes when feeding, though dives of up to 21 minutes are possible. The whale feeds by lunging forward at groups of krill, taking the animals and a large quantity of water into its mouth. The water is then squeezed out through the baleen plates by pressure from the ventral pouch and tongue. Once the mouth is clear of water, the remaining krill, unable to pass through the plates, are swallowed. The blue whale also incidentally consumes small fish, crustaceans and squid caught up with krill.
Mating starts in late autumn and continues to the end of winter. Little is known about mating behavior or breeding grounds. In the fall, males will follow females for prolonged periods of time. Occasionally, a second male will attempt to displace the first, and the whales will race each other at high speed, ranging from 17 miles per hour (27 km/h) to 20 miles per hour (32 km/h) in New Zealand. This often causes the racing whales to breach, which is rare in blue whales. This racing behavior may even escalate to physical violence between the males. Scientists have observed this behavior in multiple parts of the world, including the Gulf of St. Lawrence in Canada and the South Taranaki Bight in New Zealand.
Females typically give birth once every two to three years at the start of the winter after a gestation period of 10 to 12 months. The calf weighs about 2.5 tonnes (2.8 short tons) and is around 7 meters (23 ft) in length. Blue whale calves drink 380–570 liters (100–150 U.S. gallons) of milk a day. Blue whale milk has an energy content of about 18,300 kJ/kg (4,370 kcal/kg). The calf is weaned after six months, by which time it has doubled in length. The first video of a calf thought to be nursing was filmed on 5 February 2016. Blue whales have been occasionally known to hybridize with fin whales, and a well-documented case exists of a humpback-blue whale hybrid in the South Pacific, despite the considerable differences in size and morphology between the two species.
Sexual maturity is typically reached at five to ten years of age. In the Northern Hemisphere, whaling records show that males averaged 20–21 m (66–69 ft) and females 21–23 m (69–75 ft) at sexual maturity, while in the Southern Hemisphere it was 22.6 and 24 m (74 and 79 ft), respectively. In the Northern Hemisphere, as adults, males averaged 24 m (79 ft) and females 25 m (82 ft) with average calculated weights of 90.5 and 101.5 tonnes (100 and 112 tons), respectively. Blue whales in the eastern North Pacific population were found to be on average 0.91 meters (3.0 feet) shorter, therefore with males averaging 23.3 meters (76 feet) and 80.5 tonnes (88.5 tons) and females 24 meters (79 feet) and 90.5 tonnes (100 tons). Antarctic males averaged 25 m (82 ft) and females 26.2 m (86 ft), averaging 101.5 and 118 tonnes (112 and 130 tons). Pygmy blue whales average 19.2 meters (63 feet) at sexual maturity, with males averaging 21 meters and females 22 meters (69 and 72 feet) when fully grown, averaging 76 and 90 tonnes (83.5 and 99 tons).
In the eastern North Pacific, photogrammetric studies have shown sexually mature (but not necessarily fully grown) blue whales today average 21.7 m (71 ft), and about 65.5 tonnes (72 tons) with the largest found being about 24.5 m (80 ft). A 26.5 m (87 ft) female washed ashore near Pescadero, California in 1979.
The weight of individual blue whales varies significantly according to fat condition. Antarctic blue whales gain 50% of their lean body weight in the summer feeding season, i.e. a blue whale entering the Antarctic weighing 100 tons would leave weighing 150 tons. Pregnant females probably gain 60–65%. The fattened weight is 120% the average weight and the lean weight is 80%.
Blue whale strandings are extremely uncommon, and, because the species is largely solitary, mass strandings are unheard-of. When strandings do occur, they can become the focus of public interest. In 1920, a blue whale washed up near Bragar on the Isle of Lewis in the Outer Hebrides of Scotland. It had been shot by whalers, but the harpoon had failed to explode. As with other mammals, the fundamental instinct of the whale was to try to carry on breathing at all costs, even though this meant beaching to prevent itself from drowning. Two of the whale's bones were erected just off a main road on Lewis and remain a tourist attraction.
In June 2015, a female blue whale estimated at 12.2 meters (40 feet) and 20 tonnes (22 tons) was stranded on a beach in Maharashtra, India, the first live stranding in the region. Despite efforts by the Albaug forest department and local fishermen, the whale died 10 hours after being stranded. In August 2009, a wounded blue whale was stranded in a bay in Steingrímsfjördur, Iceland. The first rescue attempt failed, as the whale (thought to be over 20 meters long) towed the >20 ton boat back to shore at speeds of up to 7 miles per hour (11 km/h). The whale was towed to sea after 7 hours by a stronger boat. It is unknown whether it survived. In December 2015, a live blue whale thought to be over 20 meters (66 feet) long was rescued from a beach in Chile. Another stranded blue whale, thought to be about 12.2 meters (40 feet) long, was rescued in India in February 2016.
Estimates made by Cummings and Thompson (1971) suggest the source level of sounds made by blue whales are between 155 and 188 decibels when measured relative to a reference pressure of one micropascal at one meter. All blue whale groups make calls at a fundamental frequency between 10 and 40 Hz; the lowest frequency sound a human can typically perceive is 20 Hz. Blue whale calls last between ten and thirty seconds. Blue whales off the coast of Sri Lanka have been repeatedly recorded making "songs" of four notes, lasting about two minutes each, reminiscent of the well-known humpback whale songs. As this phenomenon has not been seen in any other populations, researchers believe it may be unique to the B. m. brevicauda (pygmy) subspecies. The loudest sustained noise from a blue whale was at 188 dB.
The purpose of vocalization is unknown. Richardson et al. (1995) discuss six possible reasons:
- Maintenance of inter-individual distance
- Species and individual recognition
- Contextual information transmission (for example feeding, alarm, courtship)
- Maintenance of social organization (for example contact calls between females and males)
- Location of topographic features
- Location of prey resources
Population and whaling
Blue whales are not easy to catch or kill. Their speed and power meant that they were rarely pursued by early whalers, who instead targeted sperm and right whales. In 1864, the Norwegian Svend Foyn equipped a steamboat with harpoons specifically designed for catching large whales. The harpoon gun was initially cumbersome and had a low success rate, but Foyn perfected it, and soon several whaling stations were established on the coast of Finnmark in northern Norway. Because of disputes with the local fishermen, the last whaling station in Finnmark was closed down in 1904.
Soon, blue whales were being hunted off Iceland (1883), the Faroe Islands (1894), Newfoundland (1898), and Spitsbergen (1903). In 1904–05 the first blue whales were taken off South Georgia. By 1925, with the advent of the stern slipway in factory ships and the use of steam-driven whale catchers, the catch of blue whales, and baleen whales as a whole, in the Antarctic and sub-Antarctic began to increase dramatically. In the 1930–31 season, these ships caught 29,400 blue whales in the Antarctic alone. By the end of World War II, populations had been significantly depleted, and, in 1946, the first quotas restricting international trade in whales were introduced, but they were ineffective because of the lack of differentiation between species. Rare species could be hunted on an equal footing with those found in relative abundance.
Arthur C. Clarke, in his 1962 book Profiles of the Future, was the first prominent intellectual to call attention to the plight of the blue whale. He mentioned its large brain and said, "we do not know the true nature of the entity we are destroying."
All of the historical coastal Asian groups were driven to near-extinction in short order by Japanese industrial hunts. Those groups that once migrated along western Japan to the East China Sea were likely wiped out much earlier, as the last catches on Amami Ōshima were between the 1910s and the 1930s, and the last known stranding records on the Japanese archipelago, excluding the Ryukyu Islands, were over a half-century ago. Commercial catches were continued until 1965 and whaling stations targeting blues were mainly placed along the Hokkaido and Sanriku coasts.
Blue whale hunting was banned in 1966 by the International Whaling Commission, and illegal whaling by the Soviet Union finally halted in the 1970s, by which time 330,000 blue whales had been caught in the Antarctic, 33,000 in the rest of the Southern Hemisphere, 8,200 in the North Pacific, and 7,000 in the North Atlantic. The largest original population, in the Antarctic, had been reduced to a mere 360 individuals, about 0.15% of their initial numbers.
Population and distribution today
The global population was reduced by more than 99% during the 20th century. Most of this was in the Antarctic, which had been reduced to 360 individuals or about 0.15% of their original numbers; other populations were not as badly depleted. The Antarctic blue whale population is growing at the relatively rapid rate of about 7.3% per year, but it was hunted to such a low level that it remains at a tiny fraction of pre-whaling numbers. The global population still requires protection, but it is not in immediate danger of extinction.
Since the introduction of the whaling ban, studies have examined whether the conservation reliant global blue whale population is increasing or remaining stable. In the Antarctic, best estimates show an increase of 7.3% per year since the end of illegal Soviet whaling, but numbers remain at under 1% of their original levels. Recovery varies regionally, and the Eastern North Pacific blue whale population (historically a relatively small proportion of the global total) has rebounded to about 2,200 individuals, an estimated 97% of its pre-hunting population.
The total world population was estimated to be between 5,000 and 12,000 in 2002; there are high levels of uncertainty in available estimates for many areas. A more recent estimate by the IUCN puts the global population at 10,000–25,000.
The IUCN Red List counts the blue whale as "endangered", as it has since the list's inception. In the United States, the National Marine Fisheries Service lists them as endangered under the Endangered Species Act. The largest known concentration, consisting of about 2,800 individuals, is the northeast Pacific population of the northern blue whale (B. m. musculus) subspecies that ranges from Alaska to Costa Rica, but is most commonly seen from California in summer. Infrequently, this population visits the northwest Pacific between Kamchatka and the northern tip of Japan.
In the North Atlantic, two stocks of B. m. musculus are recognized. The first is found off Greenland, Newfoundland, Nova Scotia and the Gulf of Saint Lawrence. This group is estimated to total about 500. The second, more easterly group is spotted from the Azores in spring to Iceland in July and August; it is presumed the whales follow the Mid-Atlantic Ridge between the two volcanic islands. Beyond Iceland, blue whales have been spotted as far north as Spitsbergen and Jan Mayen, though such sightings are rare. Scientists do not know where these whales spend their winters. The total North Atlantic population is estimated to be between 600 and 1,500. Off Ireland, the first confirmed sightings were made in 2008, since then Porcupine Seabight has been regarded as a prominent habitat for the species along with fin whales. One was sighted along Galicia, Spain, in 2017.
Occasionally blue whales get lost in the Baltic Sea. The remnants of two blue whales have been identified in Finland. One 19-meter skeleton was found on the bottom of the Gulf of Finland during the construction of Nord Stream pipeline. The vertebrae of a second individual were recovered from a field near Pori on the coast of the Bothnian Sea in 1942 and identified in the Copenhagen Zoological Museum by Magnus Degerbøl. Radiocarbon dating revealed the former had wandered into the Littorina Sea over 7000 years ago and perished, while the latter bones were shown to be 800–900 years old.
Five or more subpopulations have been suggested, and several of these mainly in the western North Pacific have been considered either functionally or virtually extinct. Of the populations that once existed off coastal Japan, the last recorded confirmed stranding was in the 1910s. Today, call types suggest only two populations in the North Pacific. There were also small, but constant catch records around the Korean Peninsula and in the coastal waters of the Sea of Japan; this species is normally considered not to frequent into marginal seas, such as the Sea of Okhotsk, on usual migrations. Whales were known to migrate further north to eastern Kamchatka, the Gulf of Anadyr, off Abashiri or the southern Sea of Okhotsk, and the Commander Islands. Only three sightings were made between 1994 and 2004 in Russia with one sighted off east coast of the peninsula in 2009, and the last known occurrence in the eastern Sea of Okhotsk was in 1948. In addition, whales have not been confirmed off the Commander Islands for over past 80 years. In 2017, 13 or more whales were observed off Kamchatka and Commander Islands. Historically, wintering grounds existed off the Hawaiian Archipelago, the Northern Mariana Islands, the Bonin Islands and Ryukyu Islands, the Philippines, Taiwan, the Zhoushan Archipelago, and the South China Sea such as in Daya Bay, off the Leizhou Peninsula, and off Hainan Island, and further south to the Paracel Islands. A stranding was recorded in Wanning in 2005.
By 2014, the eastern North Pacific blue whale population had rebounded to an estimated 2,200 individuals, which is thought to be about 97% of its pre-whaling numbers.
Southern Hemisphere and vicinity to Northern Indian Ocean
In the Southern Hemisphere, there appear to be two distinct subspecies, B. m. intermedia, the Antarctic blue whale, and the little-studied pygmy blue whale, B. m. brevicauda, found in Indian Ocean waters. The most recent surveys (midpoint 1998) provided an estimate of 2,280 blue whales in the Antarctic (of which fewer than 1% are likely to be pygmy blue whales). Estimates from a 1996 survey show that 424 pygmy blue whales were in a small area south of Madagascar (the Madagascar Plateau) alone, thus it is likely that numbers in the entire Indian Ocean are in the thousands. If this is true, the global numbers would be much higher than estimates predict. However, slower reproduction rate of the species, along with the impacts of whaling, may affect population recoveries as the total population size is predicted to be at less than 50% of its pre-whaling state by 2100.
Several congregating grounds were recently confirmed in Oceania, such as Perth Canyon off Rottnest Island, the Great Australian Bight off Portland, and in South Taranaki Bight and off Kahurangi Point which was discovered just in 2007 and confirmed in 2014, representing a possibly unique population based on haplotypes. Southern blue and pygmy blue females use waters off Western Australia, and coastal areas of eastern North Island of New Zealand, from Northland waters such as the Bay of Islands and Hauraki Gulf to the Bay of Plenty in the south, as breeding and calving grounds. Whales off southern and western Australia are known to migrate into tropical coastal waters in Indonesia, Philippines, and off East Timor. (Animals in the Philippines may or may not originate from North Pacific populations or from a pygmy blue population in the northern Indian Ocean as whales regularly appear off Bohol, north of the Equator.) At least on occasions, whales also migrate through remote islands such as Cook Islands, and Chilean pelagic waters adjacent to Easter Island and Isla Salas y Gómez, where possibilities of undiscovered wintering grounds have been considered.
A fourth subspecies, B. m. indica, was identified by Blyth in 1859 in the northern Indian Ocean, but is now thought to be the same subspecies as B. m. brevicauda, the pygmy blue whale. Records for Soviet catches seem to indicate that the female adult size is closer to that of the pygmy blue than B. m. musculus; the populations of B. m. indica and B. m. brevicauda appear to be discrete, and the breeding seasons differ by almost six months. Along mainland Indian coasts, appearances of whales had been scarce excluding unconfirmed record(s), the first blue whale since after the last stranding record in Maharashtra in 1914, was sighted off Kunkeshwar along with several Bryde's whales in May 2015.
Migratory patterns of these subspecies are not well known. For example, pygmy blue whales have been recorded in the northern Indian Ocean (Oman, Maldives and Sri Lanka), where they may form a distinct resident population. Furthermore, sightings have been recorded from elsewhere in and adjacent to Arabian Sea, including from Gulf of Aden, Persian Gulf, coasts of Bay of Bengal including Bangladesh to Myanmar, and within the Strait of Malacca. The first official confirmation within Thailand's EEZ occurred at Trang in 2013.
In addition, the population of blue whales occurring off Chile and Peru may also be a distinct subspecies. Some Antarctic blue whales approach the eastern South Atlantic coast in winter, and occasionally, their vocalizations are heard off Peru, Western Australia, and in the northern Indian Ocean. In Chile, the Cetacean Conservation Center, with support from the Chilean Navy, is undertaking extensive research and conservation work on a recently discovered feeding aggregation of the species off the coast of Chiloe Island in the Gulf of Corcovado (Chiloé National Park), where 326 blue whales were spotted in 2007. In this region, it is normal for blue whales to enter Fiords. Whales also reach southern Los Lagos, such as off Caleta Zorra, live along with other rorquals.
Threats other than hunting
Due to their enormous size, power and speed, adult blue whales have virtually no natural predators. There is one documented case in National Geographic Magazine of a blue whale being attacked by orcas off the Baja California Peninsula; the orcas were unable to kill the animal outright during their attack, but the blue whale sustained serious wounds and probably died as a result of them shortly after the attack. In March 2014, a pack of orcas harassed a blue whale off California, with one of them biting the tip of the blue whale's tail fluke. The blue whale attempted to tail slap the orca and fled at high speed. A similar incident happened on 18 May 2017 in Monterey Bay, with the orcas swimming in a line up to the blue whale's side. The blue whale fled and escaped. Orcas have virtually no chance against an adult blue whale, but may attack them on occasion anyway for their own enjoyment. Up to a quarter of the blue whales identified in Baja bear scars from orca attacks.
Blue whales may be wounded, sometimes fatally, after colliding with ocean vessels, as well as becoming trapped or entangled in fishing gear. Ship strikes in particular have killed many blue whales in California. In September 2007, three dead blue whales washed up in southern California after being killed by ship strikes. A similar incident occurred in northern California in 2017, possibly also 2010. Ship strikes are also a serious problem in Sri Lanka, and scientists believe this problem could be nearly eliminated by moving the shipping lanes 15 nautical miles to the south. The ever-increasing amount of ocean noise, including sonar, drowns out the vocalizations produced by whales, which makes it harder for them to communicate. Blue whales stop producing foraging D calls once a mid-frequency sonar is activated, even though the sonar frequency range (1–8 kHz) far exceeds their sound production range (25–100 Hz). Research on blue whales in the Southern California Bight has shown that mid-frequency sonar use interferes with foraging behavior, sometimes causing the whales to abandon their feeding. Human threats to the potential recovery of blue whale populations also include accumulation of polychlorinated biphenyl (PCB) chemicals within the whale's body.
With global warming causing glaciers and permafrost to melt rapidly and allowing a large amount of fresh water to flow into the oceans, there are concerns that if the amount of fresh water in the oceans reaches a critical point, there will be a disruption in the thermohaline circulation. Considering the blue whale's migratory patterns are based on ocean temperature, a disruption in this circulation, which moves warm and cold water around the world, would be likely to have an effect on their migration. The whales summer in the cool, high latitudes, where they feed in krill-abundant waters; they winter in warmer, low latitudes, where they mate and give birth.
The change in ocean temperature would also affect the blue whale's food supply. The warming trend and decreased salinity levels would cause a significant shift in krill location and abundance.
Before modern whaling began in the late 19th century, blue whales were obscure and very poorly understood. They, along with other large whales were mythologized and indistinguishable from sea monsters. Even after the first specimens were described, the blue whale went by many names and scientists often described their specimens as new species. Descriptions and illustrations were inaccurate. The taxonomy was eventually resolved, but many mysteries remained.
The blue whale rose from relative obscurity in the 1970s, after the release of the Songs of the Humpback Whale. The difference between the humpback and the blue whale was not well known to most people, who conflated the species in their minds. To many listeners, the haunting songs seemed like a cry for help. Environmentalists developed the image of a lonely blue whale singing out in an empty ocean, since whalers had nearly hunted the species to extinction.
There are many popular misconceptions about the blue whale, including that the blue whale's arteries can be swum through, that the heartbeat can be heard from 19 miles away, and that the blue whale penis is 16 feet long.
Museums with mounted skeletons include the Natural History Museum, London; University of California, Santa Cruz; New Bedford Whaling Museum in New Bedford, Massachusetts; North Carolina Museum of Natural Sciences in Raleigh, North Carolina; South African Museum in Cape Town. A skeleton at the Canadian Museum of Nature in Ottawa was unveiled in May 2010, and in 2016 the Royal Ontario Museum in Toronto began exhibiting the skeleton of a blue whale, which died in Newfoundland and Labrador in 2014. The Beaty Biodiversity Museum at the University of British Columbia, Canada, houses a skeleton (skull is cast replica) directly on the main campus boulevard. The Museum of Natural History in Gothenburg, Sweden, contains the only stuffed blue whale in the world, with its skeleton mounted beside it. Two skeletons are held in Ukraine: in Odessa and Kherson.
The Aquarium of the Pacific in Long Beach, California, features a life-size model of a mother blue whale with her calf suspended from the ceiling of its main hall. The Tokyo National Museum in Ueno Park displays a life-sized model of a blue whale in the front. Several other institutions such as Tokai University and Taiji Whale Museum hold skeletons or skeleton models of Pygmy blue whales, while several churches and buildings in western Japan including Nagasaki Prefecture display the jawbone of captured animals as a gate.
Blue whales may be encountered (but rarely) on whale-watching cruises in the Gulf of Maine and are the main attractions along the north shore of the Gulf of Saint Lawrence and in the Saint Lawrence estuary. Blue whales can also be seen off Southern California, starting as early as March and April, with the peak between July and September. More whales have been observed close to shore along with fin whales.
In Chile, the Alfaguara project combines conservation measures for the population of blue whales feeding off Chiloé Island with whale watching and other ecotourism activities that bring economic benefits to the local people. Whale-watching, principally blue whales, is also carried out south of Sri Lanka. Whales are widely seen along the coast of Chile and Peru near the coast, occasionally making mixed groups with fin, sei, and Bryde's whales.
In Australia, pygmy blue and Antarctic blue whales have been observed from various tours in almost all the coastlines of the continent. Among these, tours with sightings likely the highest rate are on west coast such as in Geographe Bay and in southern bight off Portland. For later, special tours to observe pygmy blues by helicopters are organized.
- Reilly, S. B.; Bannister, J. L.; Best, P. B.; Brown, M.; Brownell Jr., R. L.; Butterworth, D. S.; Clapham, P. J.; Cooke, J.; Donovan, G. P.; Urbán, J. & Zerbini, A. N. (2008). "Balaenoptera musculus". The IUCN Red List of Threatened Species. 2008: e.T2477A9447146. doi:10.2305/IUCN.UK.2008.RLTS.T2477A9447146.en.
- "American Cetacean Society Fact Sheet – Blue Whales". Archived from the original on 11 July 2007. Retrieved 20 June 2007.
- "Assessment and Update Status Report on the Blue Whale Balaenoptera musculus" (PDF). Committee on the Status of Endangered Wildlife in Canada. 2002. Archived from the original on 15 September 2014. Retrieved 19 April 2007.
- Paul, Gregory S. (2016). The Princeton Field Guide to Dinosaurs (Second ed.). Princeton University Press. p. 19. ISBN 978-1-4008-8314-1.
- Bortolotti, Dan (2008). Wild Blue: A Natural History of the World's Largest Animal. St. Martin's Press. ISBN 978-1-4299-8777-6.
- "Species Fact Sheets: Balaenoptera musculus (Linnaeus, 1758)". Fisheries and Aquaculture Department, Food and Agriculture Organization, United Nations. Archived from the original on 27 February 2009. Retrieved 24 December 2012.
- de Koning, Jason; Wild, Geoff (1997). "Contaminant analysis of organochlorines in blubber biopsies from blue whales in the St. Lawrence Seaway". Trent University. Archived from the original on 4 July 2007. Retrieved 29 June 2007.
- Branch, T. A.; Matsuoka, K.; Miyashita, T. (2004). "Evidence for increases in Antarctic blue whales based on Bayesian modelling". Marine Mammal Science. 20 (4): 726–754. doi:10.1111/j.1748-7692.2004.tb01190.x.
- McGrath, Matt (5 September 2014). "California blue whales bounce back to near historic numbers". BBC News. Archived from the original on 20 November 2018. Retrieved 19 November 2018.
*Hines, Sandra (5 September 2014). "California blue whales rebound from whaling; first of their kin to do so". University of Washington. Archived from the original on 8 September 2014. Retrieved 8 September 2014.
*Morell, Virginia (5 September 2014). "California blue whales bounce back". American Association for the Advancement of Science. Archived from the original on 20 November 2018. Retrieved 19 November 2018.
- Árnason, Úlfur; Lammers, Fritjof; Kumar, Vikas; Nilsson, Maria A.; Janke, Axel (2018). "Whole-genome sequencing of the blue whale and other rorquals finds signatures for introgressive gene flow". Science Advances. 4 (4): eaap9873. doi:10.1126/sciadv.aap9873.
- Bianucci, G.; Marx, F. G.; Collareta, A.; Di Stefano, A.; Landini, W.; Morigi, C.; Varola, A. (2019). "Rise of the titans: baleen whales became titans earlier than thought". Biology Letters. 15 (5): 20190175. doi:10.1098/rsbl.2019.0175. PMC 6548731. PMID 31039728.
*"Domburg (Miocene to of Netherlands)". PBDB.
*Vernimmen, Tim (30 April 2019). "Fossil of 85-foot blue whale is largest ever discovered". National Geographic.
*"Fossilworks Dataway". Fossilworks Gateway to Paleontology. Archived from the original on 21 April 2018. Retrieved 20 April 2018.
*Deméré, Thomas A.; Berta, Annalisa; McGowen, Michael R. (June 2005). "The Taxonomic and Evolutionary History of Fossil and Modern Balaenopteroid Mysticetes" (PDF). Journal of Mammalian Evolution. 12 (1/2): 99–143. doi:10.1007/s10914-005-6944-3.
- Jones, Mary Lou; Swartz, Steven L. (1984). The Gray whale: Eschrichtius robustus. Academic Press. p. 25. ISBN 978-0-12-389180-8.
- Mead, J. G.; Brownell, R. L. Jr. (2005). "Order Cetacea". In Wilson, D. E.; Reeder, D. M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 725. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Arnason, U.; Gullberg, A.; Widegren, B. (1993). "Cetacean mitochondrial DNA control region: sequences of all extant baleen whales and two sperm whale species". Molecular Biology and Evolution. 10 (5): 960–970. doi:10.1093/oxfordjournals.molbev.a040061. PMID 8412655.
- Sasaki, T.; et al. (2011). "Mitochondrial phylogenetics and evolution of mysticete whales". Systematic Biology. 54 (1): 77–90. doi:10.1080/10635150590905939. PMID 15805012.
- Arnason, A.; Gullberg, A. (1993). "Comparison between the complete mtDNA sequences of the blue and fin whale, two species that can hybridize in nature". Journal of Molecular Evolution. 37 (4): 312–322. doi:10.1007/BF00178861. PMID 8308901.
- "Amazing Whale Facts Archive". Whale Center of New England (WCNE). 17 March 2009. Archived from the original on 17 March 2009. Retrieved 27 February 2008.
- Palumbi, S. R.; Cipriano, F. (1998). "Species Identification Using Genetic Tools: The Value of Nuclear and Mitochondrial Gene Sequences in Whale Conservation" (PDF). Journal of Heredity. 89 (5): 459–464. doi:10.1093/jhered/89.5.459. PMID 9768497.
- Simpson, D. P. (1968). Cassell's Latin dictionary: Latin-English, English-Latin. Cassell. ISBN 978-0-02-522570-1.
- Linnaeus, C. (1758). Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I (in Latin) (Editio decima, reformata ed.). Holmiae: Laurentii Salvii. p. 824.
- "Blue Whale Fact Sheet". New York State Department of Environmental Conservation. Archived from the original on 30 September 2007. Retrieved 29 June 2007.
- Ichihara, T. (1966). "The pygmy blue whale B. m. brevicauda, a new subspecies from the Antarctic". Whales, dolphins and porpoises. pp. 79–113.
- Salleh, Anna (6 May 2015). "Hunting not to blame for pygmy blue whale's tiny gene pool". ABC Science. Archived from the original on 22 June 2016. Retrieved 31 July 2016.
- "Size and Description of the Blue Whale Species". Whale and Dolphin Conservation Society. Archived from the original on 1 October 2007. Retrieved 15 June 2007.
- Mackintosh, N. A.; Wheeler, J. F. G. (1929). "Southern blue and fin whales". Discovery Reports. I: 259–540.
- Double, Michael C.; Andrews-Goff, Virginia; Jenner, K. Curt S.; Jenner, Micheline-Nicole; Laverick, Sarah M.; Branch, Trevor A.; Gales, Nicholas J. (2014). "Migratory Movements of Pygmy Blue Whales (Balaenoptera musculus brevicauda) between Australia and Indonesia as Revealed by Satellite Telemetry". PLoS One. 9 (4): e93578. doi:10.1371/journal.pone.0093578.
- Owen, Kylie; Jenner, Curt S.; Jenner, Micheline-Nicole M.; Andrews, Russel D. (2016). "A week in the life of a pygmy blue whale: migratory dive depth overlaps with large vessel drafts". Animal Biotelemetry. 4: 17. doi:10.1186/s40317-016-0109-4.
- Nishiwaki, Masaharu (1950). On the Body Weight of Whales (PDF) (Report). Archived from the original (PDF) on 8 August 2016.
- Lockyer, C. (1976). "Body Weights of some Species of Large Whales". ICES Journal of Marine Science. 36 (3): 259–273. doi:10.1093/icesjms/36.3.259.
- Perrin, William F.; Wursig, Bernd; Thewissen, J. G. M. 'Hans', eds. (2009). Encyclopedia of Marine Mammals. Academic Press. p. 120. ISBN 978-0-08-091993-5.
- Wood, Gerald L. (1982). The Guinness Book of Animal Facts and Feats. Guinness Superlatives. ISBN 978-0-85112-235-9.
- Sears, R.; Calambokidis, J. (2002). "Update COSEWIC status report on the blue whale Balaenoptera musculus in Canada". Committee on the Status of Endangered Wildlife in Canada, Ottawa.: 32.
- Small, George L. (1971). The Blue Whale. Columbia University Press.[page needed]
- Mackintosh, N. A. (1943). "The southern stocks of whalebone whales". Discovery Reports. XXII (3889): 199–300. Bibcode:1944Natur.153..569F. doi:10.1038/153569a0.
- Walsh, Quentin R. (2010). Capelotti, P. J. (ed.). The Whaling Expedition of the Ulysses, 1937–38. University Press of Florida. p. 28.
- Nishiwaki, Masaharu; Hayashi, Kazuo (1948). Biological Survey of Fin and Blue Whales taken in 1947–1948 by the Japanese Fleet (PDF) (Report). Archived (PDF) from the original on 8 August 2016. Retrieved 11 July 2016.
- Lockyer, C. (1978). "Growth and Energy Budgets of Large Baleen Whales from the Southern Hemisphere". In Food and Agriculture Organization of the United Nations. Working Party on Marine Mammals (ed.). Mammals in the Seas: General papers and large cetaceans. Food & Agriculture Org. pp. 503–. ISBN 978-92-5-100513-2.
- Potvin, Jean; Goldbogen, Jeremy A.; Chadwick, Robert E. (2012). "Metabolic Expenditures of Lunge Feeding Rorquals Across Scale: Implications for the Evolution of Filter Feeding and the Limits to Maximum Body Size". PLoS One. 7 (9): e44854. doi:10.1371/journal.pone.0044854.
- The Scientific Monthly. American Association for the Advancement of Science. 1915. p. 21.
- Blue Planet: Frozen seas (BBC documentary)
- Gough, Zoe (20 August 2015). "See the world's biggest heart". BBC Earth. Archived from the original on 23 August 2015. Retrieved 21 August 2015.
- Tinker, Spencer Wilkie (1988). Whales of the World. p. 76.
- "Reproduction". University of Wisconsin. Archived from the original on 30 July 2012. Retrieved 3 October 2012.
- "Longest animal penis". Guinness World Records. Archived from the original on 5 September 2017.
the longest penis belongs to the blue whale at up to 2.4 m (8 ft).
- Long, John A. (2012). The Dawn of the Deed: The Prehistoric Origins of Sex. University of Chicago Press. p. 24. ISBN 978-0-226-49254-4.
- McClain, Craig R.; Balk, Meghan A.; Benfield, Mark C.; Branch, Trevor A.; Chen, Catherine; Cosgrove, James; Dove, Alistair D. M.; Gaskins, Lindsay C.; Helm, Rebecca R.; Hochberg, Frederick G.; Lee, Frank B.; Marshall, Andrea; McMurray, Steven E.; Schanche, Caroline; Stone, Shane N.; Thaler, Andrew D. "Sizing ocean giants: patterns of intraspecific size variation in marine megafauna". PeerJ. 3: e715. doi:10.7717/peerj.715.
- "Detailed Information about Blue Whales". Alaska Fisheries Science Center. 2004. Archived from the original on 15 January 2008. Retrieved 14 June 2007.
- Hjort, J.; Ruud, J. T. (1929). "Whaling and fishing in the North Atlantic". Rapp. Proc. Verb. Conseil Int. Explor. Mer. 56 (3151): 475–476. Bibcode:1930Natur.125..475G. doi:10.1038/125475b0.
- Christensen, I.; Haug, T.; Øien, N. (1992). "A review of feeding and reproduction in large baleen whales (Mysticeti) and sperm whales Physeter macrocephalus in Norwegian and adjacent waters". Fauna Norvegica Series A. 13: 39–48.
- Sears, R.; Wenzel, F. W.; Williamson, J. M. (1987). "The Blue Whale: A Catalogue of Individuals from the Western North Atlantic (Gulf of St. Lawrence)". Mingan Island Cetacean Study, St. Lambert, Quebec.: 27.
- Sears, R. (1990). "The Cortez blues". Whalewatcher. 24 (2): 12–15.
- Kawamura, A. (1980). "A review of food of balaenopterid whales". Scientific Reports of the Whales Research Institute. 32: 155–197.
- Yochem, P. K.; Leatherwood, S. (1980). "Blue whale Balaenoptera musculus (Linnaeus, 1758)". In Ridgway, S. H.; Harrison, R. (eds.). Handbook of Marine Mammals, Vol. 3: The Sirenians and Baleen Whales. London: Academic Press. pp. 193–240.
- "Blue whale". WWF. Archived from the original on 16 March 2014. Retrieved 11 March 2014.
- Piper, Ross (2007). Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals. Greenwood Press.[page needed]
- Marshall, Michael (December 2010). "Blue whale feeding methods are ultra-efficient". New Scientist. Archived from the original on 11 May 2015. Retrieved 24 August 2017.
- Coghlan, Andy (May 2009). "Migrating blue whales rediscover 'forgotten' waters". New Scientist. Archived from the original on 2 April 2015. Retrieved 24 August 2017.
- Goldbogen, J. A.; Calambokidis, J.; Oleson, E.; Potvin, J.; Pyenson, N. D.; Schorr, G. & Shadwick, R. E. (2011). "Mechanics, hydrodynamics and energetics of blue whale lunge feeding: efficiency dependence on krill density". Journal of Experimental Biology. 214 (Pt 1): 131–146. doi:10.1242/jeb.048157. PMID 21147977.
- Nemoto, T. (1957). "Foods of baleen whales in the northern Pacific". Sci. Rep. Whales Res. Inst. 12: 33–89.
- Nemoto, T.; Kawamura, A. (1977). "Characteristics of food habits and distribution of baleen whales with special reference to the abundance of North Pacific sei and Bryde's whales". Rep. Int. Whal. Comm. 1 (Special Issue): 80–87.
- Torres, Leigh (3 February 2016). "The Power and Beauty of Two Blue Whales Racing". National Geographic: Explorer's Journal. Archived from the original on 15 August 2016. Retrieved 8 July 2016.
- Oftedal, Olav T. (1997). "Lactation in Whales and Dolphins: Evidence of Divergence Between Baleen- and Toothed-Species". J Mammary Gland Biol Neoplasia. 2 (3): 224. PMID 10882306.
- Clark Howard, Brian (2 March 2016). "Exclusive Video May Be First to Show Blue Whale Calf Nursing". National Geographic News. Archived from the original on 4 March 2016. Retrieved 5 March 2016.
- Reeves, Randall R.; Stewart, Brent S.; Clapham, Phillip J.; Powell, James A. (2002). National Audubon Society Guide to Marine Mammals of the World (1st ed.). Alfred A. Knopf. pp. 89–93. ISBN 0375411410.
- Klinowska, Margaret (1991). Dolphins, Porpoises and Whales of the World: The IUCN Red Data Book. IUCN. ISBN 978-2-88032-936-5.
- Evans, Peter G. H. (1987). The Natural History of Whales and Dolphins. Random House.
- Monnahan, C. C.; Branch, T. A.; Stafford, K. M.; Ivashchenko, Y. V.; Oleson, E. M. (2014). "Estimating Historical Eastern North Pacific Blue Whale Catches Using Spatial Calling Patterns". PLoS One. 9 (6): e98974. doi:10.1371/journal.pone.0098974.
- Branch, T. A. (2008). Biological Parameters for Pygmy Blue Whales (Report). International Whaling Commission. SC/60/SH6.
- Gilpatrick, James W.; Perryman, Wayne L. (2008). "Geographic variation in external morphology of North Pacific and Southern Hemisphere blue whales (Balaenoptera musculus)"". J. Cetacean Res. Manage. 10 (1): 9–21.
- "Blue whale skeleton at Seymour Center at Long Marine Lab" (PDF). Seymour Marine Discovery Center. Archived (PDF) from the original on 24 June 2016. Retrieved 31 July 2016.
- "Blue Whale". National Parks Conservation Association. Archived from the original on 29 March 2012. Retrieved 21 June 2007.
- Calambokidis, J.; Steiger, G. H.; Cubbage, J. C.; Balcomb, K. C.; Ewald, C.; Kruse, S.; Wells, R. & Sears, R. (1990). "Sightings and movements of blue whales off central California from 1986–88 from photo-identification of individuals". Rep. Whal. Comm. 12: 343–348.
- Perrin, William; Geraci, Joseph. "Stranding". Encyclopedia of Marine Mammals. pp. 1192–1197.
- "The Whale Bone Arch". Places to Visit around the Isle of Lewis. Archived from the original on 5 November 2014. Retrieved 18 May 2005.
- Lukose, Anjali (26 June 2015). "Blue whale dies after being stranded on land for ten long hours". Indian Express. Archived from the original on 23 June 2016. Retrieved 2 July 2016.
- "Beached Blue Whale Rescued in Iceland's West Fjords". Iceland Review. 4 August 2009. Archived from the original on 7 August 2016. Retrieved 7 July 2016.
- Lomas, Claire (30 December 2015). "Huge beached blue whale saved by fishermen off Chile coast". The Telegraph. Archived from the original on 12 May 2018. Retrieved 4 April 2018.
- Chatterjee, Badri (4 February 2016). "In pics: 40-feet blue whale rescued at Ratnagiri". Hindustan Times. Archived from the original on 10 June 2016. Retrieved 24 June 2016.
- Cummings, William C.; Thompson, Paul O. (1971). "Underwater sounds from the blue whale Balaenoptera musculus". Journal of the Acoustical Society of America. 50 (4B): 1193–1198. Bibcode:1971ASAJ...50.1193C. doi:10.1121/1.1912752.
- Richardson, W. John; Greene, Charles R. Jr.; Malme, Charles I.; Thomson, Denis H. (1998). Marine Mammals and Noise. Gulf Professional. ISBN 978-0-12-588441-9.[page needed]
- National Marine Fisheries Service (2002). "Endangered Species Act – Section 7 Consultation Biological Opinion" (PDF). Archived from the original (PDF) on 6 September 2005.
- Scammon, Charles Melville (1874). The Marine Mammals of the Northwestern Coast of North America: Together with an Account of the American Whale-fishery. Heyday. p. 319. ISBN 978-1-59714-061-4.
- Gillespie, Alexander (2005). Whaling Diplomacy: Defining Issues in International Environmental Law. Edward Elgar Publishing. p. 23.
- Clarke, Arthur C. (1962). Profiles of the Future: an Inquiry into the Limits of the Possible. New York: Harper & Row.
- "シャチ Orcinus orca (Linneus, 1758) マイルカ科" (PDF). 海域自然環境保全基礎調査 – 海棲動物調査報告書 [Marine Environment Conservation Basic Survey – Marine Animal Research Report]. 自然環境保全基礎調査 (in Japanese). Nature Conservation Bureau of Ministry of the Environment (Japan). 1998. p. 54. Retrieved 16 January 2015.
- Miyazaki, N.; Nakayama, K. (1989). "奄美大島近海における鯨類の記録〔英文〕" [Records of Cetaceans in the Waters of the Amami Islands] (PDF). 国立科学博物館専報 [Mem. Natn. Sci. Mus., Tokyo] (in Japanese). 22: 235–249. Archived from the original on 12 January 2015. Retrieved 16 January 2015 – via CiNii.
- Gambell, R. (1979). "The blue whale". Biologist. 26: 209–215.
- Best, P. B. (1993). "Increase rates in severely depleted stocks of baleen whales". ICES Journal of Marine Science. 50 (2): 169–186. doi:10.1006/jmsc.1993.1018.
- Yablokov, A. V. (1994). "Validity of whaling data". Nature. 367 (6459): 108. Bibcode:1994Natur.367..108Y. doi:10.1038/367108a0.
- "DNA study confirms Icelandic whalers didn't kill a protected blue whale". Iceland Magazine. 19 July 2018. Archived from the original on 20 July 2018. Retrieved 19 July 2018.
- "Blue Whales". American Cetacean Society. Archived from the original on 3 September 2016. Retrieved 4 September 2016.
- Hines, Sandra (5 September 2014). "California blue whales rebound from whaling; first of their kin to do so". University of Washington. Archived from the original on 8 September 2014.
- "Endangered Species Act". Archived from the original on 26 August 2009. Retrieved 26 August 2009.
- Blue Whale (Balaenoptera musculus): Eastern North Pacific Stock (PDF). NOAA Stock Reports (Report). 2009. p. 178.
- Whooley, Pádraig (September 2008). "Blue whales sighted off Irish coast". Wildlife Extra News. Archived from the original on 26 April 2014. Retrieved 25 April 2014.
- Rey, M. (2017). "Confirman o avistamento "histórico" da balea azul na ría de Muros e Noia". GCiencia. Archived from the original on 14 September 2017. Retrieved 14 September 2017.
- Korteniemi, Jarmo (13 March 2018). "Suomalaisen sinivalaan tarina". www.tiedetuubi.fi (in Finnish). Archived from the original on 13 March 2018. Retrieved 14 March 2018.
- "Jättiläisen jäljillä". Tiede (in Finnish). 8 February 2011. Archived from the original on 13 March 2018. Retrieved 14 March 2018.
- Ukkonen, Pirkko; Mannermaa, Kristiina (2017). Jääkauden jälkeläiset - Suomen lintujen ja nisäkkäiden varhainen historia. Helsinki, Finland: Museovirasto. p. 230. ISBN 978-951-616-281-5.
- Thomas, Peter; Reeves, Randall R.; Brownell Jr, Robert L. (2015). "Status of the world's baleen whales". Marine Mammal Science. 32 (2): 682. doi:10.1111/mms.12281.
- Yamada, T.; Watanabe, Y. "Marine Mammals Stranding DataBase – Blue Whale". National Museum of Nature and Science. Archived from the original on 24 September 2017. Retrieved 23 September 2017.
- Uni, Y. (2006). "Whales, Dolphins and Porpoises off Shiretoko" (PDF). Bulletin of the Shiretoko Museum. 27: 37–46. Archived from the original (PDF) on 14 July 2014. Retrieved 16 December 2015.
- Chernyagina, A. A.; Burdin, A. M.; Artyuhin, Y. B.; Danilin, D. D.; Lobkova, L. E.; Tokranov, A. M.; Artyuhin, Y. B.; Gerasimov, N.; Lobkov, E. G.; Zagrebelnyi, S. V.; Nicanor, A. P.; Fil, V. I.; Shulezhko, T. S.; Chernyagina, O. A.; Gimelbrant, D. E.; Kirichenko, V. E.; Selivanov, O. (2013). Справочник-определитель редких и охраняемых видов живот- ных и растений Камчатского края [Handbook of rare and protected species of animals and plants of the Kamchatka Territory] (PDF). Kamchatka Branch FGBUN Pacific Institute of Geography, Petropavlovsk-Kamchatsky: Kamchatpress. ISBN 978-5-9610-0216-4. Archived (PDF) from the original on 14 May 2014. Retrieved 9 June 2014.
- "В акватории Камчатки встречены синие киты!" [In the water area of Kamchatka, blue whales were found!]. Ministry of Natural Resources of Russia. 5 July 2017. Archived from the original on 21 August 2017. Retrieved 21 August 2017.
- "Review of Cetacean Distribution and Occurrence off the Western Coast of Kamchatka, eastern Okhotsk Sea". ResearchGate.
- Mamaev, E. (2012). "The fauna of marine mammals of Commander Islands: investigations and modern status" (PDF). Marine Mammals of the Holarctic Collection of Scientific Papers Volume 2 – After the Seventh International Conference Suzdal, Russia, September 24–28, 2012: 50–54. Archived from the original (PDF) on 20 January 2015. Retrieved 20 January 2015.
- "Whalewatcher's delight in Kamchatka". The Heritage Expedition. 2017. Archived from the original on 30 July 2017. Retrieved 21 August 2017.
"Incredible Whale watching again". The Heritage Expedition. 2017. Archived from the original on 21 August 2017. Retrieved 21 August 2017.
- "Identification Guide for Marine Mammals in the South China Sea". Sanya Institute of Deep-sea Science and Engineering at the Chinese Academy of Sciences. Archived from the original on 19 January 2015. Retrieved 19 January 2015.
- Huang, Hui; Dong, Zhi-jun; Lian, Jian-sheng (November 2008). "论西沙群岛珊瑚礁生态系统自然保护区的建立" [Establishment of the Xisha Islands Coral Reef Ecosystem Nature Reserve]. 热 带 地 理 [Tropical Geography]. 28 (6): 540–544. Archived from the original on 3 March 2016. Retrieved 7 January 2015.
- "鲸豚搁浅事件列表" [List of whale strandings]. Sanya Institute of Deep-sea Science and Engineering at the Chinese Academy of Sciences. Archived from the original on 19 January 2015. Retrieved 19 January 2015.
- Branch, T. A. (2007). "Abundance of Antarctic blue whales south of 60°S from three complete circumpolar sets of surveys". Journal of Cetacean Research and Management. 9 (3): 87–96.
- Branch, T. A.; Abubaker, E. M. N.; Mkango, S.; Butterworth, D. S. (2007). "Separating southern blue whale subspecies based on length frequencies of sexually mature females". Marine Mammal Science. 23 (4): 803–833. doi:10.1111/j.1748-7692.2007.00137.x.
- "Blue Whale". Madagascar. WCS. Archived from the original on 11 October 2016.
- Best, P. B.; et al. (2003). "The abundance of blue whales on the Madagascar Plateau, December 1996". Journal of Cetacean Research and Management. 5 (3): 253–260. hdl:11427/17294. Retrieved 31 July 2016.
- Kirby, Alex (19 June 2003). "Science seeks clues to pygmy whale". BBC News. Archived from the original on 30 July 2004. Retrieved 21 April 2006.
- CSIRO (2017). "Post-whaling recovery of Southern Hemisphere". Phys.org. Archived from the original on 21 August 2017. Retrieved 22 August 2017.
- Torres, G. L. (2013). "Evidence for an unrecognised blue whale foraging ground in New Zealand". New Zealand Journal of Marine and Freshwater Research. 47 (2): 235–248. doi:10.1080/00288330.2013.773919.
- Torres, P.; Klinck, H.; et al. (2016). "Blue whale ecology in the South Taranaki Bight region of New Zealand – January-February 2016 Field Report" (PDF). Archived from the original (PDF) on 3 March 2017. Retrieved 3 March 2017.
*Harper, L. (2014). "Blue whale dine out off Taranaki in their dozens". Stuff.co.nz. Archived from the original on 16 April 2017. Retrieved 2 March 2017.
- "Sail and sailing, cruising, boating news". Sail-World.com. Archived from the original on 26 April 2014.
- "Blue whale, namataan sa Bohol". GMA News Online. Archived from the original on 27 April 2014. Retrieved 27 April 2014.
- "Global whale hot spot discovered off East Timor". Reuters. 31 December 2008. Archived from the original on 24 September 2015. Retrieved 30 June 2017.
- "Sciency Thoughts: Satellite tracking Pygmy Blue Whales". 12 April 2014. Archived from the original on 12 June 2016. Retrieved 2 June 2016.
- "Large Marine Vertebrates Project Philippines". Archived from the original on 27 April 2014. Retrieved 26 April 2014.
*Large Marine Vertebrates Project Philippines. "Media". Archived from the original on 18 May 2015. Retrieved 14 May 2015.
- "Cook Islands Biodiversity: Balaenoptera musculus – Blue Whale". Archived from the original on 13 March 2016. Retrieved 12 March 2016.
*"GEF Project Site Maps" (PDF). thegef.org. 13 March 2016. Archived from the original (PDF) on 13 March 2016.
*"Ramiros – Palmerinhas Coastal Area of Conservation near Mussulo Peninsula Island Submission of Scientific Information to Describe the Ecologically or Biologically Significant Marine Areas in Angola for the workshop in Namibia" (PDF). Archived (PDF) from the original on 3 August 2016. Retrieved 8 February 2016.
- Hucke-Gaete, R.; Aguayo-Lobo, A.; Yancovic-Pakarati, S.; Flores, M. (2014). "Marine mammals of Easter Island (Rapa Nui) and Salas y Gómez Island (Motu Motiro Hiva), Chile: a review and new records" (PDF). Lat. Am. J. Aquat. Res. 42 (4): 743–751. doi:10.3856/vol42-issue4-fulltext-5.
- "Submission of Scientific Information to Describe the Ecologically or Biologically Significant Marine Areas in Angola for the workshop in Namibia" (PDF). Archived (PDF) from the original on 3 August 2016. Retrieved 8 February 2016.
"Blue whales in Angola: new publication". ketosecology.co.uk. Archived from the original on 13 February 2016. Retrieved 8 February 2016.
- "Mauritania". wildscope.com. Archived from the original on 4 March 2016. Retrieved 8 February 2016.
- "A note on the distribution and abundance of blue whales (Balaenoptera musculus) in the Central and Northeast North Atlantic" (PDF). Archived (PDF) from the original on 1 July 2016. Retrieved 8 February 2016.
- Branch, T. A.; Stafford, K. M.; Palacios, D. M. (2007). "Past and present distribution, densities and movements of blue whales Balaenoptera musculus in the Southern Hemisphere and northern Indian Ocean". Mammal Review. 37 (2): 116–175. doi:10.1111/j.1365-2907.2007.00106.x.
- Sathasivam, K. (2015). "A Catalogue of Indian Marine Mammal Records" (PDF). Archived from the original (PDF) on 24 February 2017.
- Chatterjee, Badri (20 May 2015). "Maharashtra: Blue whales spotted off Sindhudurg coast after 100yrs". Hindustan Times. Archived from the original on 29 January 2016. Retrieved 23 January 2016.
*"Blue whale returns to Maharashtra waters, last sighting was in 1914". Indian Express. 21 May 2015. Archived from the original on 31 January 2016. Retrieved 23 January 2016.
*Chari, Mridula (23 May 2015). "Why the sightings of rare blue whales off the Konkan have thrilled scientists". scroll.in. Archived from the original on 30 January 2016. Retrieved 23 January 2016.
- Steele-Collins, Elizabeth (30 July 2013). "White whale in Middleton". The Times. Archived from the original on 18 May 2015. Retrieved 14 May 2015.
- Charles, A.; Branch, T. A.; Alagiyawadu, A.; Baldwin, R.; Marsac, F. (2012). "Seasonal distribution, movements and taxonomic status of blue whales (Balaenoptera musculus) in the northern Indian Ocean". Journal of Cetacean Resources and Management. 12 (2): 203–218.
- "Trapped blue whale in Trang swims free". Thailand News. 2013. Archived from the original on 25 February 2017.
- Hucke-Gaete, Rodrigo (2008). Blue Whales in Chile: The Giants of Marine Conservation (PDF) (Report). Rufford Small Grants Foundation. Archived (PDF) from the original on 28 October 2014. Retrieved 22 March 2009.
- "Blue Whale – Balaenoptera musculus". OBIS-SEAMAP, Duke University. Retrieved 18 August 2019.
- Melcón, M. L.; Cummins, A. J.; Kerosky, S. M.; Roche, L. K.; Wiggins, S. M.; Hildebrand, J. A. (2012). "Blue Whales Respond to Anthropogenic Noise". PLoS ONE. 7 (2): e32681. Bibcode:2012PLoSO...732681M. doi:10.1371/journal.pone.0032681. PMC 3290562. PMID 22393434.
- Tarpy, C. (1979). "Killer whale attack!". National Geographic. 155 (4): 542–545.
- "Killer Whales Bully Lone Blue Whale in Rare Video". Archived from the original on 22 June 2016.
- "Killer Whales Attacked a Blue Whale—Here's the Surprising Reason Why". National Geographic. 25 May 2017. Archived from the original on 29 July 2017. Retrieved 29 July 2017.
- Reeves, R. R.; Clapham, P. J.; Brownell, R. L.; Silber, G. K. (1998). Recovery plan for the blue whale (Balaenoptera musculus) (PDF). Silver Spring, MD: National Marine Fisheries Service. p. 42. Archived (PDF) from the original on 11 January 2012. Retrieved 20 June 2007.
- Morell, Virginia (23 July 2014). "Blue whales being struck by ships". Science. Archived from the original on 16 August 2016. Retrieved 8 July 2016.
- "Dead blue whale, fetus wash ashore in San Mateo County". The Mercury News. 16 October 2010. Archived from the original on 14 March 2018. Retrieved 14 March 2018.
- Rogers, Paul (27 May 2017). "Blue whale washes up dead along Northern California beach". Santa Cruz Sentinel. Archived from the original on 14 March 2018. Retrieved 14 March 2018.
- "Research into blue whale ship strikes off Sri Lanka offers solution to deadly threat". International Fund for Animal Welfare. Archived from the original on 19 August 2016. Retrieved 8 July 2016.
- Goldbogen, J. A.; et al. (2013). "Blue whales respond to simulated mid-frequency military sonar". Proceedings of the Royal Society B. 280 (765): 20130657. doi:10.1098/rspb.2013.0657. PMC 3712439. PMID 23825206. Retrieved 22 September 2016.
- Schiermeier, Quirin (2007). "Climate change: a sea change". Nature. 439 (7074): 256–260. Bibcode:2006Natur.439..256S. doi:10.1038/439256a. PMID 16421539. (subscription required); see also "Atlantic circulation change summary". RealClimate.org. 19 January 2006. Archived from the original on 14 February 2012. Retrieved 6 July 2011.
- Robinson, Robert A.; Learmonth, Jennifer A.; Hutson, Anthony M.; Macleod, Colin D.; Sparks, Tim H.; Leech, David I.; Pierce, Graham J.; Rehfisch, Mark M. & Crick, Humphrey Q. P. (August 2005). "Climate Change and Migratory Species" (PDF). BTO. Archived from the original (PDF) on 28 October 2014. Retrieved 9 July 2007.
- Hucke-Gaete, Rodrigo; Osman, Layla P.; Moreno, Carlos A.; Findlay, Ken P. & Ljungblad, Don K. (2003). "Discovery of a Blue Whale Feeding and Nursing Ground in Southern Chile". Proceedings of the Royal Society of London. Series B: Biological Sciences. 271 Suppl 4: s170–s173. doi:10.1098/rsbl.2003.0132. PMC 1810017. PMID 15252974.
- Moline, Mark A.; Claustre, Herve; Frazer, Thomas K.; Schofield, Oscar & Vernet, Maria (2004). "Alteration of the Food Web Along the Antarctic Peninsula in Response to a Regional Warming Trend". Global Change Biology. 10 (12): 1973–1980. Bibcode:2004GCBio..10.1973M. CiteSeerX 10.1.1.486.7880. doi:10.1111/j.1365-2486.2004.00825.x.
- "Exhibition: RBC Blue Water Gallery". Canadian Museum of Nature. Archived from the original on 14 January 2012. Retrieved 13 August 2012.
- "The Blue Whale Exhibition – Tickets". Royal Ontario Museum. Archived from the original on 19 March 2017. Retrieved 20 March 2017.
- "The Blue Whale Project". Beaty Biodiversity Museum. Vancouver, BC: University of British Columbia. 2010. Archived from the original on 4 April 2010. Retrieved 2 May 2010.
- "Скарби університету: Скелет синього кита" [Treasures of the University: Blue whale skeleton]. Press Service of Odessa National University named after I. I. Mechnikov. Archived from the original on 28 April 2016. Retrieved 18 April 2016.
- "Online Learning Center – Blue Whale". Aquarium of the Pacific. Archived from the original on 4 August 2009. Retrieved 12 August 2009.
- "Topic: Pygmy blue whale (Balaenoptera musculus)". Museum of New Zealand Te Papa Tongarewa. Archived from the original on 2 July 2015. Retrieved 29 June 2015.
The suspended skeleton in Mountains to the Sea...
- Wenzel, F. W.; Mattila, D. K.; Clapham, P. J. (1988). "Balaenoptera musculus in the Gulf of Maine". Mar. Mammal Sci. 4 (2): 172–175. doi:10.1111/j.1748-7692.1988.tb00198.x.
- "Blue whales spotted in unusually large numbers off Southern California shore". The Huffington Post. 21 September 2010. Archived from the original on 28 December 2011. Retrieved 2 April 2012.
- Alfaguara project (PDF) (Report). Rufford Small Grants Foundation. January 2008. Archived (PDF) from the original on 28 October 2014. Retrieved 1 April 2012.
- Wijeyeratne, Gehan de Silva. "Is southern Sri Lanka the world's top spot for seeing Blue and Sperm whales?". wildlifeextra.com. Archived from the original on 10 August 2011. Retrieved 15 April 2011.
- "Blue Whales arrive in Geographe Bay". Whale watching & Deep sea fishing charters in South West Australia. Archived from the original on 19 April 2015. Retrieved 14 May 2015.
- HeliExplore. YouTube. Archived from the original on 27 May 2015. Retrieved 14 May 2015.
- Westerskov, Kim. "Blue Whale Feeding Near Shore New Zealand ストックフォト 91275736". Getty Images. Archived from the original on 26 April 2014. Retrieved 25 April 2014.
- Blue whale vocalizations – Cornell Lab of Ornithology—Bioacoustics Research Program
- Blue whale video clips and news from the BBC – BBC Wildlife Finder
- Voices in the Sea – Sounds of the Blue Whale