The common minke whale or northern minke whale (''Balaenoptera acutorostrata'') is a species of
minke whale
The minke whale (), or lesser rorqual, is a species complex of baleen whale. The two species of minke whale are the common (or northern) minke whale and the Antarctic (or southern) minke whale. The minke whale was first described by the Danish n ...
within the suborder of
baleen whale
Baleen whales (systematic name Mysticeti), also known as whalebone whales, are a parvorder of carnivorous marine mammals of the infraorder Cetacea (whales, dolphins and porpoises) which use keratinaceous baleen plates (or "whalebone") in their ...
s.
It is the smallest species of the
rorqual
Rorquals () are the largest group of baleen whales, which comprise the family Balaenopteridae, containing ten extant species in three genera. They include the largest animal that has ever lived, the blue whale, which can reach , and the fin wha ...
s and the second smallest species of
baleen whale
Baleen whales (systematic name Mysticeti), also known as whalebone whales, are a parvorder of carnivorous marine mammals of the infraorder Cetacea (whales, dolphins and porpoises) which use keratinaceous baleen plates (or "whalebone") in their ...
. Although first ignored by whalers due to its small size and low oil yield, it began to be exploited by various countries beginning in the early 20th century. As other species declined larger numbers of common minke whales were caught, largely for their meat. It is now one of the primary targets of the whaling industry. There is a dwarf form in the Southern Hemisphere.
This species is known in the fossil record from the
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...
period (age range: 3.6 million years ago to present day).
Vernacular names
The origins of the species' common name are obscure. One of the first references to the name came in
Henrik Johan Bull
Henrik Johan Bull (13 October 18441 June 1930) was a Norwegian businessman and whaler. Henry Bull was one of the pioneers in the exploration of Antarctica.
Biography
Henrik Johan Bull was born at Stokke in Vestfold County, Norway. He attended sc ...
's account of his 1893–95 voyage to the Antarctic, when he mentioned catching a small whale "called in the Arctic language a Mencke whale, after a German who accompanied Mr. Foyn on some of his voyages."Bull, H. J. (1896). ''The cruise of the 'Antarctic' to the South Polar regions''. London: Edward Arnold. According to the British writer
John Guille Millais
John Guille Millais ( , also ; 24 March 1865 – 24 March 1931) was a British artist, naturalist, gardener and travel writer who specialised in wildlife and flower portraiture. He travelled extensively around the world in the late Victorian p ...
(''The mammals of Great Britain and Ireland'', 1906, vol. 3, p. 279), "Minkie was a Norwegian seaman who was always calling 'Hval' at whatever backfin he saw. He is now regarded as the type of the 'tenderfoot' at sea. Norwegians often refer to any small whale with some contempt or amusement as a 'Minkie' or 'Minkie's hval'."Allen, G. M. (1916). ''The whalebone whales of New England''. Boston. The American
marine biologist
Marine biology is the scientific study of the biology of marine life, organisms in the sea. Given that in biology many scientific classification, phyla, family (biology), families and genera have some species that live in the sea and others th ...
and painter Richard Ellis, citing the Norwegian scientist Age Jonsgård, stated "that Meincke was a German laborer working for Svend Foyn, inventor of the grenade harpoon. Meincke 'one day mistook a school of this whale species for blue whales.... most probably he made this mistake during Foyn's whaling operations in the
Varanger Fjord
The Varangerfjord ( en, Varanger Fjord; russian: Варангер-фьорд, Варяжский залив; fi, Varanginvuono; sme, Várjavuonna) is the easternmost fjord in Norway, north of Finland. The fjord is located in Troms og Finnmark co ...
between 1868 and 1885."Ellis, Richard. 1980. ''The Book of Whales''. Alfred Knopf, New York.
It has formerly been known as the little piked whale, the lesser or least rorqual, and the sharp-headed finner. American whalemen in the 19th century simply thought of them as "young finbacks" or a "Finback's calf", apparently under the impression that they were juveniles of their larger relative, the
fin whale
The fin whale (''Balaenoptera physalus''), also known as finback whale or common rorqual and formerly known as herring whale or razorback whale, is a cetacean belonging to the parvorder of baleen whales. It is the second-longest species of cet ...
. They were also called zwergwal (
German
German(s) may refer to:
* Germany (of or related to)
** Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
: "dwarf whale") or vågehval (
Norwegian
Norwegian, Norwayan, or Norsk may refer to:
*Something of, from, or related to Norway, a country in northwestern Europe
* Norwegians, both a nation and an ethnic group native to Norway
* Demographics of Norway
*The Norwegian language, including ...
: "bay whale"). In Japan they are called koiwashi-kujira ("little sardine whale") or minku-kujira ("minke whale").Omura, H. and H. Sakiura. (1956). "Studies on the little piked whale from the coast of Japan". ''Sci. Rep. Whales Res. Inst.'', 11: 1-37. In
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...
they are known by the
Danish
Danish may refer to:
* Something of, from, or related to the country of Denmark
People
* A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark
* Culture of Denmark
* Danish people or Danes, people with a Danish a ...
name sildepisker ("herring thresher").
Taxonomy
History
Otto Fabricius
Otto Fabricius (6 March 174420 May 1822) was a Danish missionary, naturalist, ethnographer, and explorer of Greenland.
Biography
Otto Fabricius was born in Rudkøbing on the island of Langeland, Denmark, where his father was a rector. In his ...
, in his ''Fauna Groenlandica'' (1780), was the first to describe the minke, noting its small size and white baleen – but he described it erroneously under the name ''Balaena rostrata'' (the taxonomic designation for the beaked whale). In 1804, Baron de Lacepede named it ''Balaenoptera acuto-rostrata'', basing his description partly on the stranding of a juvenile female near
Cherbourg, France
Cherbourg-Octeville () is a former commune in the Manche department in Normandy in north-western France.
in 1791.True, F. W. (1904). ''The whalebone whales of the western North Atlantic: Compared with those occurring in European waters''. Washington: Smithsonian institution.
In 1872, the American whaleman and naturalist
Charles Melville Scammon
Charles Melville Scammon (1825–1911) was a 19th-century whaleman, naturalist, and author. He was the first to hunt the gray whales of both Laguna Ojo de Liebre and San Ignacio Lagoon, the former also known as "Scammon's Lagoon" after him. In ...
described and named ''Balaenoptera davidsoni'', after an pregnant female that was found dead on the north shore of
Admiralty Inlet
Admiralty Inlet is a strait in the U.S. state of Washington connecting the eastern end of the Strait of Juan de Fuca to Puget Sound. It lies between Whidbey Island and the northeastern part of the Olympic Peninsula.
Boundaries
It is general ...
in October 1870 in then
Washington Territory
The Territory of Washington was an organized incorporated territory of the United States that existed from March 2, 1853, until November 11, 1889, when the territory was admitted to the Union as the State of Washington. It was created from the ...
(now
Washington state
Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washington ...
) and towed into
Port Townsend Bay
Port Townsend Bay, also called Port Townsend, is a marine inlet off Admiralty Inlet at the northeastern extreme of the Olympic Peninsula in the U.S. state of Washington
Washington commonly refers to:
* Washington (state), United States
* Washing ...
by Italian fisherman, who flensed it on the beach. Scammon mentioned its "dwarfish size", "pointed head", "falcated dorsal fin", and the "white band" on its "inordinately small, pointed pectorals". In 1877, the Italian geologist and paleontologist
Giovanni Capellini
Giovanni Capellini (23 August 1833 – 28 May 1922) was an Italians, Italian geologist and paleontologist.
He was a Senator of the Kingdom of Italy in the seventeenth legislature.
Birth and education
Giovanni Capellini was born on 23 August ...
described and named ''Sibbaldius mondini'' from a juvenile specimen that was captured off Italy in 1771. Both were later synonymized with ''B. acutorostrata''.
A smaller, Southern Hemisphere form of minke whale with white-banded flippers was first described in separate studies by Peter Best (1985) and Peter Arnold, Helene Marsh, and George Heinsohn (1987), though a white-flippered form in the Southern Hemisphere had been noted earlier. The former described a "diminutive form" based on specimens caught off
Durban
Durban ( ) ( zu, eThekwini, from meaning 'the port' also called zu, eZibubulungwini for the mountain range that terminates in the area), nicknamed ''Durbs'',Ishani ChettyCity nicknames in SA and across the worldArticle on ''news24.com'' from ...
,
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
, while the latter named a "dwarf form" based on specimens and sightings from Australia. This unnamed subspecies has a prominent white flipper and shoulder blaze and a dark throat patch, whereas what was called the "dark-shouldered" or "ordinary" form of minke whale (now known as a separate species, the Antarctic minke whale, ''B. bonaerensis'') lacked these contrasting markings.
Until recently, all minke whales were considered a single species. However, the common minke whale was recognized as a separate species from the
Antarctic minke whale
The Antarctic minke whale or southern minke whale (''Balaenoptera bonaerensis'') is a species of minke whale within the suborder of baleen whales. It is the second smallest rorqual after the common minke whale and the third smallest baleen whal ...
based on
mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...
testing. This testing also confirmed that the Antarctic minke whale is the closest relative of the common minke whale, thus confirming the validity of the minke whale
clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
.
Divergence
Common and Antarctic minke whales diverged from each other in the Southern Hemisphere 4.7 million years ago, during a prolonged period of
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
in the early
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Antarctic Circumpolar Current
The Antarctic Circumpolar Current (ACC) is an ocean current that flows clockwise (as seen from the South Pole) from west to east around Antarctica. An alternative name for the ACC is the West Wind Drift. The ACC is the dominant circulation feat ...
and created local pockets of upwelling, facilitating speciation by fragmenting populations. The radiation of common minke whales into the Northern Hemisphere occurred rapidly about 1.5 million years ago during a period of cooling in the
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
.
Hybrids
There have been two confirmed hybrids between common and Antarctic minke whales. Both were caught in the northeastern North Atlantic by Norwegian whaling vessels. The first, an female taken off western
Spitsbergen
Spitsbergen (; formerly known as West Spitsbergen; Norwegian: ''Vest Spitsbergen'' or ''Vestspitsbergen'' , also sometimes spelled Spitzbergen) is the largest and the only permanently populated island of the Svalbard archipelago in northern Norw ...
() on 20 June 2007, was the result of a pairing between a female Antarctic minke and a male common minke. The second, a pregnant female taken off northwestern Spitsbergen () on 1 July 2010, on the other hand, had a common minke mother and an Antarctic minke father. Her female fetus, in turn, was fathered by a North Atlantic common minke, demonstrating that back-crossing is possible between hybrids of the two species.
Description
Size
The common minke whale is the smallest of the
rorqual
Rorquals () are the largest group of baleen whales, which comprise the family Balaenopteridae, containing ten extant species in three genera. They include the largest animal that has ever lived, the blue whale, which can reach , and the fin wha ...
s, and one of the smallest baleen whales (second smallest only to the
Pygmy right whale
The pygmy right whale (''Caperea marginata'') is a species of baleen whale. It may be a member of the cetotheres, a family of baleen whales which until 2012 were thought to be extinct; ''C. marginata'' has otherwise been considered the monotyp ...
). In the
North Atlantic
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Africa, Europe and ...
, Norwegian whaling vessels in 1940 allegedly caught individuals of up to in length, but they were likely only measured visually in comparison to objects of known dimensions aboard the ships themselves – the longest caught in subsequent years were typically only up to in length. In the North Pacific, Soviet vessels operating out of the Kuril Islands claimed to have caught two males of 12.2 (40 ft) and and a female of – the first two were landed in 1951, the third in 1960.Ivashin, M. (1992). "USSR catch and sightings data". ''Report of the Scientific Committee on North Pacific minke whales'' (Appendix 7), p. 168. These likely represent undersized sei whales, part of the massive misreporting of whaling data by the
Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...
in the
North Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
and elsewhere.
The longest measured by
Iceland
Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...
ic scientists were an male and a female, while the longest caught by the Japanese in the western North Pacific were males and a female – the latter caught off eastern
Hokkaido
is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel.
The la ...
in 1977. For the dwarf form, the longest reported are a male caught in May 1973 and a 7.77 (25.5 ft) female caught in May 1970, both taken off South Africa.
Males caught in the western North Pacific and weighed whole on a truck scale averaged between 2.85 and 4.23 metric tons (3.14 and 4.66 short tons) (range: 0.86 to 6.36 metric tons, 0.95 to 7.01 short tons), while females averaged between 1.93 and 3.63 metric tons (2.13 and 4.00 short tons) (range: 0.84 to 8.35 metric tons, 0.93 to 9.20 short tons).Kishiro, T., Kato, H., Ohizumi, H., Yoshida, H., Saito, T., Isoda, T., Tabata, S., Sakakibara, M., Saino, S., Hara, T., Hayashi, T., Miyashita, T., Fukudome, K., Kiwada, H., and Kawahara, S. (2003). "Report of the 2002 JARPN II survey in the western North Pacific. Part II: Coastal component – Coastal survey off Kushiro, northeast Japan". ''Paper SC/55/O8 submitted to the 55th IWC Scientific Committee'', 26pp.Yoshida, H., Kato, H., Kishiro, T., Iwasaki, T., Miyashita, T., Ryono, T., Tabata, S., Sakakibara, M., Saino, S., Hara, T., Hayashi, T., Tomizawa, Y., Tamai, K., Okamoto, R., Fukuoka, M., Watanabe, H., Tsunekawa, M., and Kawahara, S. (2004). "Report of the coastal survey on common minke whales off Sanriku coast, northeast Japan: the Japanese whale research program under special permit in the western North Pacific–Phase II (JARPN II) in 2003 (Part II) – Coastal component". ''Paper SC/56/O14 submitted to the 56th IWC Scientific Committee'', 31pp.Kishiro, T., Kato, H., Yoshida, H., Miyashita, T., Ryono, T., Tabata, S., and Kawahara, S. (2005). "Cruise report of the coastal survey on common minke whales off Kushiro, northeast Japan: the 2004 JARPN II survey (Part II) – Coastal component". ''Paper SC/57/O4 submitted to the 57th IWC Scientific Committee'', 37pp.Yoshida, H., Kato, H., Kishiro, T., Iwasaki, T., Miyashita, T., Saito, T., Shigeo, T., Morita, Y., Sato, H., Okada, A., Tomizawa, Y., Saino, S., Kuroishi, H., Ebisui, T., Nakai, K., Nishiwaki, S., and S. Kawahara. (2006). "Cruise report of the second phase of the Japanese Whale Research Program under Special Permit in the western North Pacific (JARPN II) in 2005 – Coastal component off Sanriku". ''Paper SC/58/09 Submitted to the 58th IWC Scientific Committee'', 30 pp.Kishiro, T., Kato, H., Yoshida, H., Miyashita, T., Ryono, T., Tabata, S., and Kawahara, S. (2006). "Cruise report of the Second phase of the Japanese Whale Research Program under Special Permit in the western North Pacific (JARPN II) in 2005 – Coastal component off Kushiro". ''Paper SC/58/O10 submitted to the 58th IWC Scientific Committee'', 32pp.Goto, M., Kato, H., Zenitani, R., Yoshida, H., Saito, T., Tabata, S., and Kawahara, S. (2007). "Cruise report of the second phase of the Japanese Whale Research Program under Special Permit in the Western North Pacific (JARPN II) in 2006 – Coastal component off Sanriku". ''Paper SC/59/O6 submitted to the 59th IWC scientific Committee'', 34pp.Yoshida, H., Kato, H., Kishiro, T., Miyashita, T., Iwasaki, T., Minamikawa, S., and Kawahara, S. (2007). "Cruise report of the second phase of the Japanese Whale Research Program under Special Permit in the Western North Pacific (JARPN II) in 2006 – Coastal component off Kushiro". Paper SC/59/O7 submitted to the 59th IWC Scientific Committee, 43pp.Bando, T., Kato, H., Kishiro, T., Goto, M., Saito, T., Tabata, S., and Kawahara, S. (2008). "Cruise report of the second phase of the Japanese Whale Research Program under Special Permit in the Western North Pacific (JARPN II) in 2007 – Coastal component off Sanriku". ''Paper SC/60/O6 submitted to the 60th IWC scientific Committee'', 27pp.Kishiro, T., Kato, H., Yoshida, H., Miyashita, T., Iwasaki, T., Kanaji, Y., and Kawahara, S. (2008). "Cruise report of the Second phase of the Japanese Whale Research Program under Special Permit in the western North Pacific (JARPN II) in 2007 – Coastal component off Kushiro". ''Paper SC/60/O7 submitted to the 60th IWC Scientific Committee'', 33pp.
At sexual maturity, males and females in the North Atlantic average between and , while in the North Pacific they average between and . At physical maturity, males and females in the North Atlantic average between and , while in the North Pacific they are slightly smaller, averaging only , respectively. At birth, they are estimated to be in length and weigh . They are thought to be weaned at about in length. For the dwarf form, they are thought to reach sexual maturity at around for females and for males and are estimated to be about at birth.
Appearance
Northern form
Common minke whales are among the most robust members of their genus, the greatest height of their body being one-fifth their total length. They have a narrow, pointed, triangular rostrum with a low splashguard. Their prominent, upright, falcate dorsal fin averages about in height – range – and is set about two-thirds the way along the back. They are dark gray dorsally and clean white ventrally. The lower jaw projects beyond the upper jaw and is dark gray on both sides – though, like the dwarf form, it can have a ''white mandible blaze'' at the rear corner of the right lower jaw. An indistinct light gray ''rostral saddle'' may be present, and a few individuals can have pale, thin ''blowhole streaks'' trailing from the blowholes. A thin, light gray, forward-directed chevron, called the ''shoulder streak'', lies between the pectoral fins. Two light gray to whitish swaths, called the ''thorax'' and ''flank patches'', join ventrally in the mid-lateral region, with the former the brighter of the two. The pectoral fins are relatively small, averaging about 73 cm (about 2.4 ft) in length (maximum: 1.38 m, or about 4.5 ft). They have a transverse, white band on their outer margins, which is the most distinguishing feature of the species. In most individuals (about 94% in the western North Pacific) it is a clear white band, but in a minority of cases (about 6%) it only forms an obscure white band – about 29% of the individuals sampled from the Sea of Japan had this type of flipper band. The smooth-sided flukes average about in width and can be nearly 3 m (about 9.8 ft) wide. They are light gray or white ventrally and bordered by dark gray. The baleen plates, which number about 230 to 360 pairs and average about , are creamy white with a fine white fringe – a small percentage in the western North Pacific (mainly larger individuals) have a thin black band along the outer margin. They possess 50 to 70 thin ventral pleats, which only extend about 47 percent of the body length – among the shortest relative to body length among the rorquals, second only to the sei whale.Dorsey, E. M., Stern, S. J., Hoelzel, A. R., and Jacobsen, J. (1990). "Minke whales (''Balaenoptera acutorostrata'') from the west coast of North America: individual recognition and small-scale site fidelity". ''Reports of the International Whaling Commission'' (Special Issue 12): 357-368.
Dwarf form
The
dwarf minke whale
The common minke whale or northern minke whale (''Balaenoptera acutorostrata'') is a species of minke whale within the suborder of baleen whales.
It is the smallest species of the rorquals and the second smallest species of baleen whale. Althoug ...
has similar proportions to the northern form, with an upright, hooked dorsal fin set about two-thirds the way along the back that is up to in height. It has 55 to 67 ventral grooves. Its baleen – in length – is mostly white, with up to 45 per cent of the posterior plates shading from black to dusky gray along their outer margins.
The dwarf form has the most complex coloration of any baleen whale. Dark gray fields and capes alternate with light gray and white blazes, patches, and streaks. The dark gray ''spinal field'' lies above an ivory white ''ventral field''. This spinal field extends down into a ''nape field'', which separates a light gray ''rostral saddle'' and a light gray, triangular, usually forwardly peaked ''thorax patch''. The nape field, in turn, extends even further down into a ''dark throat patch'', which reaches down to the ventral pleats and extends back to the front of the pectoral fins. Further back the spinal field extends into a ''dark thorax field'', which usually forms an inverted triangle between the thorax patch and the light gray ''flank patch''. This flank patch can be separated into an ''anterior'' and ''posterior flank patch'' by a dark triangular or even wave-like ''flank infill''. Finally, the dark ''peduncle field'' covers the posterior portion of the caudal peduncle to the tips of the dorsal side of the flukes, which are white ventrally and thinly bordered by dark gray.
The most prominent features on the dwarf minke whale are the white ''flipper'' and ''shoulder blazes''. The former covers the proximal two-thirds of the pectoral fin and continues along its leading edge, while the latter connects to the thorax patch above. A variably sized, dark oval ''auxiliary patch'' (formerly called a "flipper oval") lies behind the pectoral fin, often appearing to merge with the dark gray ''distal flipper patch'', which occupies the distal third of the pectoral fin. This auxiliary patch is often completely separated from the thorax patch by the white of the shoulder blaze and a vertical extension of the ventral field, but can also narrowly or even broadly attach to it. A ''mandible blaze'' usually covers the posterior third of the right lower jaw, while the left side is normally dark gray. Similarly, a white ''eye blaze'' is usually present on the right side, but rarely on the left. The rostral saddle likewise shows asymmetrical coloration, extending further on the right side than on the left and having a more well defined posterior right margin; the left, meanwhile, often has a diffuse posterior margin. A white ''peduncle blaze'' extends up from the ventral field, being bordered on each side by light gray double ''caudal chevrons'', which extend down from the peduncle field and flank patch, respectively.
A variably shaped, thin, light gray line, called the ''nape streak'' (analogous to the "shoulder streak" or "chevron" of the northern form), extends laterally down the back between the pectoral fins. It can point forward, backwards or form a straight line; this variability can help to identify individual whales. A pair of light gray ''blowhole streaks'' extend posteriorly behind the blowholes, often curving to the left – the left more strongly than the right. Occasionally fine ''ear stripes'' may be present behind the opening of the auditory meatus, while dark or light speckling or streaking can occur along the flanks as well as what are called ''tiger stripes'' – "parallel, dark, usually vertical stripes".
Like
Bryde's whale
Bryde's whale ( Brooder's), or the Bryde's whale complex, putatively comprises three species of rorqual and maybe four. The "complex" means the number and classification remains unclear because of a lack of definitive information and research ...
(and occasionally blue and fin whales), dwarf minkes can exhibit auxiliary ridges on either side of the central ridge of the rostrum.
Distribution
Range
Common minke whales have a disjointed distribution. In the North Atlantic, they occur as far north as
Baffin Bay
Baffin Bay ( Inuktitut: ''Saknirutiak Imanga''; kl, Avannaata Imaa; french: Baie de Baffin), located between Baffin Island and the west coast of Greenland, is defined by the International Hydrographic Organization as a marginal sea of the Arct ...
,
Svalbard
Svalbard ( , ), also known as Spitsbergen, or Spitzbergen, is a Norwegian archipelago in the Arctic Ocean. North of mainland Europe, it is about midway between the northern coast of Norway and the North Pole. The islands of the group range ...
,
Franz Josef Land
, native_name =
, image_name = Map of Franz Josef Land-en.svg
, image_caption = Map of Franz Josef Land
, image_size =
, map_image = Franz Josef Land location-en.svg
, map_caption = Location of Franz Josef ...
, and
Novaya Zemlya
Novaya Zemlya (, also , ; rus, Но́вая Земля́, p=ˈnovəjə zʲɪmˈlʲa, ) is an archipelago in northern Russia. It is situated in the Arctic Ocean, in the extreme northeast of Europe, with Cape Flissingsky, on the northern island, ...
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
) and the
Hebrides
The Hebrides (; gd, Innse Gall, ; non, Suðreyjar, "southern isles") are an archipelago off the west coast of the Scottish mainland. The islands fall into two main groups, based on their proximity to the mainland: the Inner and Outer Hebrid ...
and central
North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...
during summer. There are a few records from
Hudson Bay
Hudson Bay ( crj, text=ᐐᓂᐯᒄ, translit=Wînipekw; crl, text=ᐐᓂᐹᒄ, translit=Wînipâkw; iu, text=ᑲᖏᖅᓱᐊᓗᒃ ᐃᓗᐊ, translit=Kangiqsualuk ilua or iu, text=ᑕᓯᐅᔭᕐᔪᐊᖅ, translit=Tasiujarjuaq; french: b ...
(
James Bay
James Bay (french: Baie James; cr, ᐐᓂᐯᒄ, Wînipekw, dirty water) is a large body of water located on the southern end of Hudson Bay in Canada. Both bodies of water extend from the Arctic Ocean, of which James Bay is the southernmost par ...
in 1986 and Button Bay in 1990), and they have also been observed occasionally in
Hudson Strait
Hudson Strait (french: Détroit d'Hudson) links the Atlantic Ocean and Labrador Sea to Hudson Bay in Canada. This strait lies between Baffin Island and Nunavik, with its eastern entrance marked by Cape Chidley in Newfoundland and Labrador ...
and
Ungava Bay
Ungava Bay (french: baie d'Ungava, ; iu, ᐅᖓᕙ ᑲᖏᖅᓗᒃ/) is a bay in northeastern Canada separating Nunavik (far northern Quebec) from Baffin Island. Although not geographically apparent, it is considered to be a marginal sea of the ...
. They have been recorded off
Madeira
)
, anthem = ( en, "Anthem of the Autonomous Region of Madeira")
, song_type = Regional anthem
, image_map=EU-Portugal_with_Madeira_circled.svg
, map_alt=Location of Madeira
, map_caption=Location of Madeira
, subdivision_type=Sovereign st ...
Freitas, L, Dinis, A. and Alves, F. (2006). "Occurrence and distribution of cetaceans off Maderia archipelago (Portugal)". ''Twentieth annual conference of the European Cetacean Society'' (poster abstract). and occur year-round off the
Canary Islands
The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...
. There are occasional sightings and strandings off Spain and Portugal, western Sahara,
Mauritania
Mauritania (; ar, موريتانيا, ', french: Mauritanie; Berber: ''Agawej'' or ''Cengit''; Pulaar: ''Moritani''; Wolof: ''Gànnaar''; Soninke:), officially the Islamic Republic of Mauritania ( ar, الجمهورية الإسلامية ...
Azores
)
, motto =( en, "Rather die free than subjected in peace")
, anthem= ( en, "Anthem of the Azores")
, image_map=Locator_map_of_Azores_in_EU.svg
, map_alt=Location of the Azores within the European Union
, map_caption=Location of the Azores wi ...
and a vagrant in the
Gulf of Mexico
The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...
and the
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...
, with a few records from the
Black Sea
The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...
(1880 and 1926). During the winter it has been recorded off
Bermuda
)
, anthem = "God Save the King"
, song_type = National song
, song = " Hail to Bermuda"
, image_map =
, map_caption =
, image_map2 =
, mapsize2 =
, map_caption2 =
, subdivision_type = Sovereign state
, subdivision_name =
, e ...
, the
Bahamas
The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the Atlantic Ocean, North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to ...
, the Antilles, the east coast of the United States south of 40°N, and in the southeastern North Atlantic between 10°40'N and 19°35'N and 22°W and 20°05'W. In the western and central
North Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
, they range from
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
, the
Mariana Islands
The Mariana Islands (; also the Marianas; in Chamorro: ''Manislan Mariånas'') are a crescent-shaped archipelago comprising the summits of fifteen longitudinally oriented, mostly dormant volcanic mountains in the northwestern Pacific Ocean, betw ...
,Norris, T., Martin, S., Thomas, L., Yack, T., Oswald, J. N., Nosal, E. M., and Janik, V. (2012). "Acoustic ecology and behavior of minke whales in the Hawaiian and Marianas Islands: localization, abundance estimation, and characterization of minke whale 'boings'". In ''The Effects of Noise on Aquatic Life'' (pp. 149-153). Springer, New York. the
East China Sea
The East China Sea is an arm of the Western Pacific Ocean, located directly offshore from East China. It covers an area of roughly . The sea’s northern extension between mainland China and the Korean Peninsula is the Yellow Sea, separated b ...
, the
Yellow Sea
The Yellow Sea is a marginal sea of the Western Pacific Ocean located between mainland China and the Korean Peninsula, and can be considered the northwestern part of the East China Sea. It is one of four seas named after common colour terms ...
and the
Sea of Japan
The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it h ...
in the south to the
Sea of Okhotsk
The Sea of Okhotsk ( rus, Охо́тское мо́ре, Ohótskoye móre ; ja, オホーツク海, Ohōtsuku-kai) is a marginal sea of the western Pacific Ocean. It is located between Russia's Kamchatka Peninsula on the east, the Kuril Islands ...
and Bering and
Chukchi Sea
Chukchi Sea ( rus, Чуко́тское мо́ре, r=Chukotskoye more, p=tɕʊˈkotskəjə ˈmorʲɪ), sometimes referred to as the Chuuk Sea, Chukotsk Sea or the Sea of Chukotsk, is a marginal sea of the Arctic Ocean. It is bounded on the west b ...
s in the north. In the eastern North Pacific, they occur in the
Gulf of Alaska
The Gulf of Alaska (Tlingit: ''Yéil T'ooch’'') is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, ...
south along the entire west coast of North America (including the U.S. states of Alaska, Washington,
Oregon
Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...
, and CaliforniaLeatherwood, S., Stewart, B. S., and Folkens, P. A. (1987). ''Cetaceans of the Channel Islands National Marine Sanctuary''. National Marine Sanctuary Program. and the Canadian province of British Columbia) down to
Baja California
Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...
and into the
Gulf of California
The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja Ca ...
.Tershy, B. R., Breese, D., and Strong, C. S. (1990). "Abundance, seasonal distribution and population composition of balaenopterid whales in the Canal de Ballenas, Gulf of California, Mexico". ''Reports of the International Whaling Commission'', ''Special'' (12): 369-375. During winter, they've been acoustically recorded mainly between 15° and 35°N in the eastern and central North Pacific.
The dwarf form has been recorded off
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
(June to February, including the states of
Maranhão
Maranhão () is a state in Brazil. Located in the country's Northeast Region, it has a population of about 7 million and an area of . Clockwise from north, it borders on the Atlantic Ocean for 2,243 km and the states of Piauí, Tocantins and ...
,
Paraíba
Paraíba ( Tupi: ''pa'ra a'íba''; ) is a state of Brazil. It is located in the Brazilian Northeast, and it is bordered by Rio Grande do Norte to the north, Ceará to the west, Pernambuco to the south and the Atlantic Ocean to the east. Paraíba ...
Espírito Santo
Espírito Santo (, , ; ) is a state in southeastern Brazil. Its capital is Vitória, and its largest city is Serra. With an extensive coastline, the state hosts some of the country's main ports, and its beaches are significant tourist attra ...
,
Rio de Janeiro
Rio de Janeiro ( , , ; literally 'River of January'), or simply Rio, is the capital of the state of the same name, Brazil's third-most populous state, and the second-most populous city in Brazil, after São Paulo. Listed by the GaWC as a b ...
,
São Paulo
São Paulo (, ; Portuguese for 'Saint Paul') is the most populous city in Brazil, and is the capital of the state of São Paulo, the most populous and wealthiest Brazilian state, located in the country's Southeast Region. Listed by the GaWC a ...
, Paraná, Santa Catarina, and Rio Grande do Sol) from 2°44'S to 33°35'S,Magalhaes, F. A., Severo, M. M., Tosi, C. H., Garri, R. G., Zerbini, A. N., Chellappa, S. and Silva, F. J. L. (2007). "Record of a dwarf minke whale (''Balaenoptera acutorostrata'') in northern Brazil". ''JMBA2 – Biodiversity Records'' published online: 2 pp.
Uruguay
Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...
,
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
, in the
Beagle Channel
Beagle Channel (; Yahgan: ''Onašaga'') is a strait in the Tierra del Fuego Archipelago, on the extreme southern tip of South America between Chile and Argentina. The channel separates the larger main island of Isla Grande de Tierra del Fuego fr ...
and Goree Passage of southern
Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
(February to April), off
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
(May to August),
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
(March to December, including
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
,
Victoria
Victoria most commonly refers to:
* Victoria (Australia), a state of the Commonwealth of Australia
* Victoria, British Columbia, provincial capital of British Columbia, Canada
* Victoria (mythology), Roman goddess of Victory
* Victoria, Seychelle ...
,
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
, and
Queensland
)
, nickname = Sunshine State
, image_map = Queensland in Australia.svg
, map_caption = Location of Queensland in Australia
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, established_ ...
),
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
(March to August),
New Caledonia
)
, anthem = ""
, image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg
, map_alt = Location of New Caledonia
, map_caption = Location of New Caledonia
, mapsize = 290px
, subdivision_type = Sovereign st ...
,
Vanuatu
Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...
,
Fiji
Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...
, and as far south as the
South Shetland Islands
The South Shetland Islands are a group of Antarctic islands with a total area of . They lie about north of the Antarctic Peninsula, and between southwest of the nearest point of the South Orkney Islands. By the Antarctic Treaty of 195 ...
,
Gerlache Strait
Gerlache Strait or de Gerlache Strait or Détroit de la Belgica is a channel/strait separating the Palmer Archipelago from the Antarctic Peninsula. The Belgian Antarctic Expedition, under Lt. Adrien de Gerlache, explored the strait in January an ...
, and the
Bellingshausen Sea
The Bellingshausen Sea is an area along the west side of the Antarctic Peninsula between 57°18'W and 102°20'W, west of Alexander Island, east of Cape Flying Fish on Thurston Island, and south of Peter I Island (there the southern ''Vostokkyste ...
(69°25'S).
Population
North Atlantic
There are estimated to be over 180,000 common minke whales in the North Atlantic. Sighting surveys conducted in the Northeastern Atlantic between 1996 and 2001 resulted in an estimated abundance of 107,205 whales, with 43,835 in the Barents Sea region, 26,718 around
Jan Mayen
Jan Mayen () is a Norwegian volcanic island in the Arctic Ocean with no permanent population. It is long (southwest-northeast) and in area, partly covered by glaciers (an area of around the Beerenberg volcano). It has two parts: larger nort ...
, 18,174 in the
Greenland Sea
The Greenland Sea is a body of water that borders Greenland to the west, the Svalbard archipelago to the east, Fram Strait and the Arctic Ocean to the north, and the Norwegian Sea and Iceland to the south. The Greenland Sea is often defined as p ...
and around the Svalbard archipelago, and 17,895 in the northern North Sea. There are an estimated 67,225 whales off Iceland. Based on an aerial survey performed in waters between northern
Disko Island
Disko Island ( kl, Qeqertarsuaq, da, Diskoøen) is a large island in Baffin Bay, off the west coast of Greenland. It has an area of ,Cape Farewell ( 60°N) during August and September 2005, there are estimated to be 4,856 individuals (95% confidence interval (CV): 1,910-12,348) off Western Greenland; a ship-based survey made during September and October of the same year came up with a similar estimate of 4,479 (95% CI: 1,760-11,394). In the Gulf of St. Lawrence, line-transect aerial surveys done in August–September 1995 and July–August 1996 estimated there were 1,020 minke whales there, with about 75% of them on the North Shore shelf.
Estimates published in 2021 (based on 2014-2019 data) indicate that there are up to 150,000 individuals in Norwegian waters. Researchers at the
Norwegian Institute of Marine Research
The Norwegian Institute of Marine Research ( no, Havforskningsinstituttet) is a national consultative research institute which is owned by the Ministry of Fisheries and Coastal Affairs. The institute performs research and provides advisory service ...
say that these estimates are 50 % higher than previous.
North Pacific
Ship-based sighting surveys that covered the Okhotsk Sea during August 1989 and August–September 1990 and adjacent areas of the Northwest Pacific during July and August 1990 estimated there were 25,049 (95% CI: 13,700-45,800) minke whales there, with 19,209 (95% CI: 10,100-36,600) in the Okhotsk Sea and 5,841 (95% CI: 2,800-12,000) in the Northwest Pacific. A sighting survey conducted in the central Bering Sea between July and August 1999 estimated there were 936 (95% CI: 473-1,852) individuals in those waters, while line-transect sighting surveys that cruised from the central
Aleutian Islands
The Aleutian Islands (; ; ale, Unangam Tanangin,”Land of the Aleuts", possibly from Chukchi language, Chukchi ''aliat'', "island"), also called the Aleut Islands or Aleutic Islands and known before 1867 as the Catherine Archipelago, are a cha ...
east to the
Kenai Peninsula
The Kenai Peninsula ( Dena'ina: ''Yaghenen'') is a large peninsula jutting from the coast of Southcentral Alaska. The name Kenai (, ) is derived from the word "Kenaitze" or "Kenaitze Indian Tribe", the name of the Native Athabascan Alaskan trib ...
from July–August 2001 – 2003 estimated there were 1,232 (95% CI: 646-2,346) whales in that area, with the majority of the sightings around the eastern Aleutian Islands, particularly in and around
Seguam Pass Seguam Pass is a strait between the Bering Sea and the North Pacific Ocean in the Aleutian Islands in Alaska. It lies between Seguam Island to the east and Amlia
Amlia ( ale, Amlax; russian: Остров Амля) is an island in the Aleutian I ...
and the
Islands of Four Mountains
Islands of Four Mountains (russian: Четырёхсопочные острова) is an island grouping of the Aleutian Islands in Alaska, United States. The chain includes, from west to east, Amukta, Chagulak, Yunaska, Herbert, Carlisle, ...
; a few sightings were also made along the
Alaska Peninsula
The Alaska Peninsula (also called Aleut Peninsula or Aleutian Peninsula, ale, Alasxix̂; Sugpiaq: ''Aluuwiq'', ''Al'uwiq'') is a peninsula extending about to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The ...
and near
Kodiak Island
Kodiak Island (Alutiiq: ''Qikertaq''), is a large island on the south coast of the U.S. state of Alaska, separated from the Alaska mainland by the Shelikof Strait. The largest island in the Kodiak Archipelago, Kodiak Island is the second larges ...
. In the coastal waters of
British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
, there are estimated to be 475 (95% CI: 221-1,020) whales based on sightings from ship-based line-transect surveys made during the summers of 2004 and 2005.
Southern Hemisphere
There are no population estimates for dwarf minke whales due to sighting surveys not being able to distinguish it from the much more common Antarctic minke whale.
Occurrence
Site fidelity
Minke whales were individually identified using the shape of the dorsal fin and nicks along its edges, variations in lateral body pigmentation, and small oval scars in three separate study sites on the western coast of North America. These individuals showed strong small-scale site fidelity. A total of 55 whales were identified, 30 in the
San Juan Islands
The San Juan Islands are an archipelago in the Pacific Northwest of the United States between the U.S. state of Washington and Vancouver Island, British Columbia, Canada. The San Juan Islands are part of Washington state, and form the core of ...
of
Washington state
Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washington ...
from 1980 to 1984, 17 in the
Monterey Bay
Monterey Bay is a bay of the Pacific Ocean located on the coast of the U.S. state of California, south of the San Francisco Bay Area and its major city at the south of the bay, San Jose. San Francisco itself is further north along the coast, by a ...
area of central
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
from 1984 to 1987, and eight in the
Johnstone Strait
, image = Pacific Ranges over Johnstone Strait.jpg
, image_size = 250px
, alt =
, caption = Johnstone Strait backdropped by the Vancouver Island Ranges
, image_bathymetry = Carte baie Knight ...
area of
British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
from 1981 to 1987 – although in the last region most were only photographed incidentally to the study of
killer whale
The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus ''Orcinus'' and is recognizable by its black-and-white pa ...
s. The number of sightings per individual ranged from only one in one year to 37 over nine years, with 31 whales (56.4%) being sighted in at least two years and 12 (21.8%) being seen in at least five years. Most were seen exclusively or almost exclusively in one of three sub-regions in the San Juan Islands and one of two sub-regions in the Monterey Bay area.
In the San Juan Islands, 14 out of 18 whales were within their primary range on at least 94 per cent of sightings. Of the three sub-regions, Range A, northwest of
Orcas Island
Orcas Island () is the largest of the San Juan Islands of the Pacific Northwest, which are in the northwestern corner of San Juan County, Washington.
History and naming of the island
The name "Orcas" is a shortened form of ''Horcasitas,'' fro ...
, had the most stable constituency, with five individuals seen repeatedly over the study period, accounting for all but one of 88 sightings. Range B, east of
San Juan Island
San Juan Island is the second-largest and most populous of the San Juan Islands in northwestern Washington, United States. It has a land area of 142.59 km2 (55.053 sq mi) and a population of 6,822 as of the 2000 census.
Washington State Fe ...
, had the least stable constituency as well as the lowest number of sightings per year, while Range C, south and west of San Juan Island, had the greatest number of sightings and the greatest number of identified individuals every year. One whale, S4, was repeatedly and consistently found in Range B for three years, but was never seen there again after 1982; few sightings were made since then and all of these occurred in 1984, most of them involving three whales that were usually found in Range A (S8, S10, and S13). In Range C, five whales were seen there every year, while seven were only seen in a single year – most of the latter individuals were never encountered in any other part of the study site. There were also whales that showed no site fidelity at all, moving freely between the sub-regions. For example, whale S9, although only being sighted five times over four years, had sightings evenly divided between ranges B and C; whale S5, on the other hand, encountered 27 times over the course of eight years, was seen in more than one range in most years and moved around the three sub-regions more than any other whale.
In the Monterey Bay area, Range A was north of the deep-water canyon that runs into
Carmel Bay
Carmel Bay is a bay of the Pacific Ocean, along the central coast of California in Monterey County. The bay is long and wide with its mouth about across, between Point Carmel to the south and Point Cypress to the north; Monterey Bay is about f ...
, while Range B was south of that canyon. Individuals were sighted within one of the two ranges on at least 88 per cent of the sightings, with whales even being observed to turn around as they approached the border of their primary range and head back toward the middle of their range – this happened five times at the northern border and twice at the southern border of Range A, and six times at the northern border of Range B. Whales were sighted within of the coast, occasionally just outside the kelp, most of the time moving in a more or less straight line.
During a study conducted around the
Isle of Mull
The Isle of Mull ( gd, An t-Eilean Muileach ) or just Mull (; gd, Muile, links=no ) is the second-largest island of the Inner Hebrides (after Skye) and lies off the west coast of Scotland in the Council areas of Scotland, council area of Arg ...
, northwest Scotland, between 1990 and 1999 during the months of May to October, 66 minke whales were photo-identified based on the shape of the dorsal fin and distinctive notches and marks on it, body scars, and white oval scars – lateral body pigmentation was often not visible. Of these, 30 were seen at least twice, with 21 of them sighted in more than one year; one individual was identified 27 times over the course of ten years. During a similar study performed during whale watching cruises in the southern outer
Moray Firth
The Moray Firth (; Scottish Gaelic: ''An Cuan Moireach'', ''Linne Mhoireibh'' or ''Caolas Mhoireibh'') is a roughly triangular inlet (or firth) of the North Sea, north and east of Inverness, which is in the Highland council area of north of Scotl ...
, northeast Scotland, between 2001 and 2007 from May to October, 34 individuals were photo-identified. Fourteen of them (41%) were sighted one or more times, while seven individuals (20%) were seen in one or more years. One whale was seen three times between 2002 and 2006; another four times between 2001 and 2006; and a third a total of eight times between 2001 and 2006.Gill, A., Fairbairns, B., and Fairbairns, R. (2000). "Photo-identification of the minke whale (''Balaenoptera acutorostrata'') around the Isle of Mull, Scotland". ''Report to the Hebridean Whale and Dolphin Trust''.Baumgartner, N. (2008). ''Distribution, diving behaviour and identification of the North Atlantic minke whale in northeast Scotland'' (Doctoral dissertation, Aberdeen University).
In a photo-identification study of minke whales off Iceland conducted between 2001 and 2010, a total of 353 whales were individually identified: 292 in
Faxaflói
Faxaflói (sometimes Faxa Bay, Faxe Bay or Faxi Bay,Thorstein Thorsteinsson. 1930. ''Iceland, 1930: A Handbook Published on the Fortieth Anniversary of Landsbanki Íslands (National Bank of Iceland)''. Reykjavík: Ríkisprentsmidjan Gutenberg. i ...
Bay, on the southwest coast, and 61 in
Skjálfandi Skjálfandi (; also known as Skjálfandaflói ) is a bay in northern Iceland, with some of the characteristics of a fjord. The Icelandic word ''Skjálfandi'' literally translates to ''trembling'' which may refer to earthquakes in the area.
The bay ...
Bay, on the northeast coast. In Faxaflói Bay, 68 (23.3%) were resighted at least once, with 53 (18.2%) being resighted in two years, nine (3.1%) in three years, and six (2.1%) in four years. The majority in Skjálfandi was only sighted in one year, while ten (16.4%) were resighted at least once, four (6.6%) in two years, and six (9.8%) in three years or more. One whale, first photographed in Skjálfandi Bay in July 2002, moved repeatedly between the two study sites over a period of nearly ten years, sometimes being sighted in both areas in the same season.
In the St. Lawrence estuary, using dorsal fin shape and scars and lateral body pigmentation and scarring, a total of 209 minke whales were individually identified during the summer months between 1999 and 2004. Thirty-five were what were called "regular visitors", being sighted on at least 40 different days in four to six different years. Twenty-five showed strong small-scale site fidelity to either the Laurentian Channel Head or the Saguenay Fjord, with over three-quarters of their sightings occurring in one of these two areas.Tscherter, U. and Morris, C. (2005). "Identifying a majority of minke whales (''Balaenoptera acutorostrata'') in the St. Lawrence based on the presence of dorsal fin edge marks". In Evans, P. G. H. and V. Ridoux (eds.). ''European research on cetaceans'', Vol. 159. ''Proceedings of the 15th Annual Conference of the European Cetacean Society'', ''La Rochelle'', 2005.Morris, C. and Tscherter, U. (2006). "Site fidelity of individual minke whales (''Balaenoptera acutorostrata'') in the St. Lawrence estuary". ''Poster presented at the 20th Annual Conference of the European Cetacean Society in Gdynia'' (abstract only). Off
Nova Scotia
Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland".
Most of the population are native Eng ...
, forty individuals were reliably identified using dorsal fin notches during the summer months (mainly July and August) between 1997 and 2008. Of these, fourteen (35%) were sighted on more than one day, while only five (12.5%) were seen in more than one year.Bartha, G. B., Gowans, S., Simard, P., Tetley, M., and Keith, E. O. (2011). "Population size and site fidelity of North Atlantic minke whales (''Balaenoptera acutorostrata acutorostrata'') off the Atlantic coast of Nova Scotia, Canada". ''Aquatic Mammals'' 37 (4): 454-463 (abstract only).
Migration and movements
Three minke whales tagged off Iceland showed large-scale movements. One tagged off the north coast on 20 August 2002 first moved northeast of Iceland on 31 October before heading south, reaching on 8 November. Another, tagged in Faxaflói Bay on 14 September 2004, turned south along the
Reykjanes Ridge
The Mid-Atlantic Ridge is a mid-ocean ridge (a divergent or constructive plate boundary) located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. In the North Atlantic, the ridge separates the North Am ...
about two weeks later; its last signal was received on 8 October at about . The third traveled the greatest distance. After being tagged in Faxaflói Bay on 27 August 2004 its first signal wasn't received until 17 November, when it was over the
Mid-Atlantic Ridge
The Mid-Atlantic Ridge is a mid-ocean ridge (a divergent or constructive plate boundary) located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. In the North Atlantic, the ridge separates the North Ame ...
, west of northern
Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
. Its next position was transmitted six days later, some to the south, around the
Azores
)
, motto =( en, "Rather die free than subjected in peace")
, anthem= ( en, "Anthem of the Azores")
, image_map=Locator_map_of_Azores_in_EU.svg
, map_alt=Location of the Azores within the European Union
, map_caption=Location of the Azores wi ...
, while its last signal was received on 5 December along the
Canary Current
The Canary Current is a wind-driven surface current that is part of the North Atlantic Gyre. This eastern boundary current branches south from the North Atlantic Current and flows southwest about as far as Senegal where it turns west and later jo ...
Islands. In all, it traveled from its tagging location in a little over 100 days.Víkingsson, G. A. and M. P. Heide-Jørgensen. (2013). "Migration and local movements of common minke whales tracked by satellite in the North Atlantic during 2001-2010". ''Reports of the International Whaling Commission's Icelandic Special Meeting'', pp. 1-12.
In the eastern North Pacific, individually identified minke whales were found to make intra-annual movements between feeding areas. Two whales traveled from southern (April) to northern
Vancouver Island
Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian Provinces and territories of Canada, province of British Columbia. The island is in length, in width at its widest point, and in total area, while are o ...
(July), while one whale moved from the southwest coast of Vancouver Island (June) to its northern coast (July–September) and another from the central British Columbia coast (July) south to northern Vancouver Island (August–September). Two whales, including one of the two that had traveled from southern to northern Vancouver Island, moved from northern (June and July, respectively) to southern Vancouver Island (September).
Four dwarf minke whales were attached with satellite tags off
Lizard Island
Lizard Island is an island on the Great Barrier Reef in Queensland (Australia), northwest of Brisbane and part of the Lizard Island Group that also includes Palfrey Island. It is part of the Lizard Island National Park. Lizard Island is within ...
, on the
Great Barrier Reef
The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...
, in July 2013. All four followed the coastline south. Two stopped transmitting off southern Queensland, while the other two traveled west through the
Bass Strait
Bass Strait () is a strait separating the island state of Tasmania from the Australian mainland (more specifically the coast of Victoria, with the exception of the land border across Boundary Islet). The strait provides the most direct waterwa ...
. The third soon stopped transmitting as well. The fourth ceased sending signals on 11 October, by which time it had reached 54°23'S, traveling some from its original tagging location.
Biology
Reproduction
Whale (''Balaenoptera acutorostrata'')">penis (''Balaenoptera acutorostrata'')
Common minke whales are sexually mature at about six to eight years of age for females and about six to seven years for males. Females are promiscuous. After a gestation period of 10 months, a single calf is born – only one out of 79 mature females during a study of minke whales off Iceland had twin fetuses, an female caught in July 2006 which had a male and a female. The calf is weaned after a period of six months. Peak conception is February in the North Atlantic, late February to mid-March for the "O stock", which migrates along the eastern coast of Japan to the Okhotsk Sea), and between October and November for the "J stock" (which occurs in the
Yellow Sea
The Yellow Sea is a marginal sea of the Western Pacific Ocean located between mainland China and the Korean Peninsula, and can be considered the northwestern part of the East China Sea. It is one of four seas named after common colour terms ...
,
East China Sea
The East China Sea is an arm of the Western Pacific Ocean, located directly offshore from East China. It covers an area of roughly . The sea’s northern extension between mainland China and the Korean Peninsula is the Yellow Sea, separated b ...
, and
Sea of Japan
The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it h ...
, and migrates to the southern Okhotsk Sea in the spring, where it mixes with the O stock. Peak calving is December in the North Atlantic, December to January in the North Pacific, and May to July for the J stock.Evans, Peter G. H. (1987). ''The Natural History of Whales and Dolphins''. Facts on File. The calving interval is only a year, so females are often simultaneously pregnant and lactating. Females reach physical maturity perhaps as early as 13 years of age; another study suggested that growth ceases for both sexes when they have 15 to 20 growth layers in their tympanic bullae, which may correspond to about 15 to 20 years of age. Both sexes can live to about 50 years of age – the oldest in a study of Icelandic minke whales were 42 years for females and 47 years for males, respectively.
Prey
Common minke whales have been described as ichthyophagous, but their diet also includes pelagic crustaceans and
cephalopod
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...
s and varies by region, season, and year.
North Atlantic
In the North Atlantic, they primarily eat small schooling fish,
demersal fish
Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They occ ...
, and
krill
Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian
Norwegian, Norwayan, or Norsk may refer to:
*Something of, from, or related to Norway, a country in n ...
. A 2007 study showed that off
Spitsbergen
Spitsbergen (; formerly known as West Spitsbergen; Norwegian: ''Vest Spitsbergen'' or ''Vestspitsbergen'' , also sometimes spelled Spitzbergen) is the largest and the only permanently populated island of the Svalbard archipelago in northern Norw ...
they fed almost exclusively on members of the euphausiid genus
Thysanoessa Thysanoessa
Abstract
''Thysanoessa'' is a genus of the krill that play critical roles in the marine food web. They're abundant in Arctic and Antarctic areas, feeding on zooplankton and detritus to obtain energy. Thysanoessa are responsible for ...
(mainly ''T. inermis''), but nearly a fifth also fed on small amounts of
capelin
The capelin or caplin (''Mallotus villosus'') is a small forage fish of the smelt family found in the North Atlantic, North Pacific and Arctic oceans. In summer, it grazes on dense swarms of plankton at the edge of the ice shelf. Larger capelin ...
. A small percentage of individuals, by decreasing frequency, also fed on
polar cod
''Boreogadus saida'', known as the polar cod or as the Arctic cod, is a fish of the cod family Gadidae, related to the true cod (genus ''Gadus''). Another fish species for which both the common names Arctic cod and polar cod are used is ''Arct ...
,
Atlantic cod
The Atlantic cod (''Gadus morhua'') is a benthopelagic fish of the family Gadidae, widely consumed by humans. It is also commercially known as cod or codling.haddock
The haddock (''Melanogrammus aeglefinus'') is a saltwater ray-finned fish from the family Gadidae, the true cods. It is the only species in the monotypic genus ''Melanogrammus''. It is found in the North Atlantic Ocean and associated seas where ...
, and
copepod
Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...
s. Capelin dominated off Bear Island and in the southern
Barents Sea
The Barents Sea ( , also ; no, Barentshavet, ; russian: Баренцево море, Barentsevo More) is a marginal sea of the Arctic Ocean, located off the northern coasts of Norway and Russia and divided between Norwegian and Russian territo ...
, accounting for about three-quarters of their diet in both regions. Nearly half (nearly 46 per cent) also consumed euphausiids (''Thysanoessa spp.'') in the former area – haddock (12.5%),
blue whiting
The blue whiting (''Micromesistius poutassou'') one of the two species in the genus '' Micromesistius'' in the family Gadidae, which also contains cod, haddock, whiting, and pollock. It is common in the northeast Atlantic Ocean from Morocco to I ...
(8.3%), polar cod, Atlantic cod,
Atlantic herring
Atlantic herring (''Clupea harengus'') is a herring in the family (biology), family Clupeidae. It is one of the most abundant fish species in the world. Atlantic herrings can be found on both sides of the Atlantic Ocean, congregating in large ...
, and copepods constituted the rest. Herring and haddock were also taken in the southern Barents Sea (accounting for 41.5 and 28.7 per cent by frequency of occurrence, respectively), while
sandeel
Sand eel or sandeel is the common name used for a considerable number of species of fish. While they are not true eels, they are eel-like in their appearance and can grow up to in length. Many species are found off the western coasts of Europe ...
(''
Ammodytes
''Ammodytes'' is a genus of sand lances native to the northern oceans.
Species
There are currently 8 recognized species in this genus:
* ''Ammodytes americanus'' DeKay, 1842 (American sand lance)
* ''Ammodytes dubius'' J. C. H. Reinhardt, 18 ...
spp.''), Atlantic cod, copepods, euphausiids,
pollock
Pollock or pollack (pronounced ) is the common name used for either of the two species of North Atlantic marine fish in the genus ''Pollachius''. ''Pollachius pollachius'' is referred to as pollock in North America, Ireland and the United Kingd ...
, and blue whiting made up the rest of the diet. In the Norwegian Sea, herring was found in all individuals sampled (n= 10), with some (20 per cent each) also feeding on a small amount of capelin and blue whiting – an earlier study, based on data primarily obtained between 1943–1945, showed that they fed exclusively on herring off
Vesterålen
Vesterålen is a district and archipelago in Nordland county, Norway. It is located just north of Lofoten and west of Harstad. It is the northernmost part of Nordland county. Sortland is the largest town, situated near the center of the archipe ...
, while the diet off
Lofoten
Lofoten () is an archipelago and a traditional district in the county of Nordland, Norway. Lofoten has distinctive scenery with dramatic mountains and peaks, open sea and sheltered bays, beaches and untouched lands. There are two towns, Svolvær ...
was more varied, including herring (34 per cent by occurrence), pelagic crustaceans (23%), Atlantic cod (22%), haddock (6%), and a mixture of
coalfish
The saithe ( or ) (''Pollachius virens'') is a species of marine fish in the Pollock genus ''Pollachius''. Together with '' P. pollachius'', it is generally referred to in the United States as pollock. Other names include the Boston blue (separa ...
and
flatfish
A flatfish is a member of the Ray-finned fish, ray-finned demersal fish order (biology), order Pleuronectiformes, also called the Heterosomata, sometimes classified as a suborder of Perciformes. In many species, both eyes lie on one side of the ...
for one individual (1.5%). In the North Sea, they primarily fed on sandeel (62%) and
Atlantic mackerel
The Atlantic mackerel (''Scomber scombrus''), also known as Boston mackerel, Norwegian mackerel, Scottish mackerel or just mackerel, is a species of mackerel found in the temperate waters of the Mediterranean Sea, the Black Sea, and the northern ...
(nearly 30%), with some feeding on herring (16.2%), small amounts of
Mueller's pearlside
''Maurolicus muelleri'', commonly referred to as Mueller's pearlside, Mueller's bristle-mouth fish (not to be confused with the Gonostomatidae), or the silvery lightfish (not to be confused with the Phosichthyidae) is a marine hatchetfish in the ...
(10.8%), copepods, haddock, capelin, and whiting. They were found to feed almost exclusively on Atlantic mackerel in the northern North Sea, while the same was true for sandeel in the eastern North Sea. Off Iceland, they mainly fed on sandeel (nearly 58 per cent of sampled individuals), haddock (22.6%), herring (20%), capelin (19.4%), and Atlantic cod (14.7%), with the rest of the diet consisting of euphausiids, various larger species of gadiods, and
Norway pout
''Trisopterus esmarkii'', the Norway pout, is a species of fish in the cod family. It is found in the Barents Sea, North Sea, Baltic Sea, off the coasts of Norway, Iceland, the British Isles and elsewhere in the northeast Atlantic Ocean. It pref ...
. Sandeel was more important in southern Iceland (constituting 78 per cent of sampled individuals), while capelin (35.1%), haddock (28.7%), and cod (22.3%) were more important in the north. Euphausiids were only consumed in the north. Although haddock was only a minor part of the diet the first couple years of the study (0 and 4% in 2003 and 2004, respectively), it subsequently constituted a major component of it (31-35% in 2005–2007), while sandeel's importance in the south declined considerably (95.2 to 77.7% from 2003–2006, but only 18.1% in 2007). Off southeastern
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...
, they only fed on capelin, while sandeel dominated off southwestern Greenland. In a sample of 172 minke whales caught off Newfoundland between 1966 and 1972, the vast majority (85%) fed only on fish, mainly capelin. Some fed on a mixture of capelin and cod, while others had only consumed cod. Other gadiods, herring, krill, and squid formed the rest of the diet.
North Pacific
In the North Pacific, small schooling fish and krill are major food items. They feed exclusively on
Pacific herring
The Pacific herring (''Clupea pallasii'') is a species of the herring family associated with the Pacific Ocean environment of North America and northeast Asia. It is a silvery fish with unspined fins and a deeply forked caudal fin. The distribut ...
in the northern
Okhotsk Sea
The Sea of Okhotsk ( rus, Охо́тское мо́ре, Ohótskoye móre ; ja, オホーツク海, Ohōtsuku-kai) is a marginal sea of the western Pacific Ocean. It is located between Russia's Kamchatka Peninsula on the east, the Kuril Islands ...
and only on
Alaska pollock
The Alaska pollock or walleye pollock (''Gadus chalcogrammus'') is a marine fish species of the cod genus ''Gadus'' and family Gadidae.
It is a semi-pelagic Shoaling and schooling, schooling fish widely distributed in the North Pacific Ocean, N ...
Pacific saury
The Pacific saury (''Cololabis saira'') is a member of the family Scomberesocidae. Saury is a seafood in several East Asian cuisines and is also known by the name mackerel pike.
Biology
Saury is a fish with a small mouth, an elongated body, ...
(18%) are consumed east of the southern
Kuril Islands
The Kuril Islands or Kurile Islands (; rus, Кури́льские острова́, r=Kuril'skiye ostrova, p=kʊˈrʲilʲskʲɪjə ɐstrɐˈva; Japanese: or ) are a volcanic archipelago currently administered as part of Sakhalin Oblast in the ...
, with only the former species being found in whales sampled in September and the latter species likewise only being found in whales taken in October. Euphausiids make up nearly two-thirds of the diet (62%) around the western
Aleutian Islands
The Aleutian Islands (; ; ale, Unangam Tanangin,”Land of the Aleuts", possibly from Chukchi language, Chukchi ''aliat'', "island"), also called the Aleut Islands or Aleutic Islands and known before 1867 as the Catherine Archipelago, are a cha ...
, with unidentified fish (19%) constituting most of the rest. On the Okhotsk Sea side of
Hokkaido
is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel.
The la ...
they mainly feed on euphausiids (55%), but also take
sardine
"Sardine" and "pilchard" are common names for various species of small, oily forage fish in the herring family Clupeidae. The term "sardine" was first used in English during the early 15th century, a folk etymology says it comes from the Ital ...
(24%) and
sand lance
A sand lance or sandlance is a fish belonging to the family Ammodytidae. Several species of sand lances are commonly known as "sand eels", though they are not related to true eels. Another variant name is launce, and all names of the fish are ...
(13%); on the Pacific side of Hokkaido, they feed almost exclusively on sardine (99%). In
Sanriku
, sometimes known as , lies on the northeastern side of the island of Honshu, corresponding to today's Aomori, Iwate and parts of Miyagi Prefecture and has a long history.
The 36 bays of this irregular coastline tend to amplify the destructivenes ...
, sardine makes up the bulk of the diet (54%), but euphausiids also play an important part (32%) – only a small percentage (9%) fed on sand lance. Euphausiids were a major food item on the Okhotsk Sea side of Hokkaido and off Sanriku in the spring (71, 72 and 62% from April–June in the former area, and 83% in April in the latter area), while sardine dominated the diet in the summer in both areas (71% in September for the former region, and 70, 92, and 93% from May–July in the latter region). More recent data from Japanese scientific catches in the western North Pacific shows
Japanese anchovy
The Japanese anchovy (''Engraulis japonicus'') is a schooling fish of the family Engraulidae. It is common in the Pacific Ocean south from the Sea of Okhotsk, widespread in the Sea of Japan, Yellow Sea, and East China Sea, and near the coasts of ...
to be a major component of the diet in two of the three sub-areas (60 per cent by weight in sub-area 7 and 37.4% in sub-area 8), while Pacific saury was the major food item in sub-area 9 (64.6%) and played an important part of the diet in sub-area 8 (36.4%). Euphausiids (9.2% in all areas combined), Alaska pollock (7.8% in sub-area 7), minimal armhook squid (4.9% in sub-area 9), and mackerel were also consumed.Tamura, T., Konishi, K., Isoda, T., and P. Okamoto. (2009). "Prey consumption and feeding habits of common minke, sei and Bryde's whales in the western North Pacific". ''NAMMCO/SC/16/MMFI/07''. They are thought to feed on juvenile herring and probably sand lance (''Ammodytes hexapterus'') around the
San Juan Islands
The San Juan Islands are an archipelago in the Pacific Northwest of the United States between the U.S. state of Washington and Vancouver Island, British Columbia, Canada. The San Juan Islands are part of Washington state, and form the core of ...
, while in the
Monterey Bay
Monterey Bay is a bay of the Pacific Ocean located on the coast of the U.S. state of California, south of the San Francisco Bay Area and its major city at the south of the bay, San Jose. San Francisco itself is further north along the coast, by a ...
region they have been observed feeding on baitfish – probably
northern anchovy
The Californian anchovy or northern anchovy (''Engraulis mordax'') is a species of anchovy found in the Pacific Ocean, ranging from Mexico to British Columbia.
Relationship with humans Commercial fishing
As sardine populations declined in the Pa ...
, which is abundant there.
Southern Hemisphere
In the Southern Ocean, dwarf minkes feed mainly on myctophid fishes. An immature female caught in the sub-Antarctic had euphausiids in its stomach, while two pregnant females from the same area had consumed fish and a mature male only had
myctophids
Lanternfishes (or myctophids, from the Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family Myctophidae. One of two families in the order Myctophiformes, the Myctophidae are represente ...
in its stomach. An immature male caught in a gillnet off southern Brazil had a stomach almost filled with the euphausiid ''Euphausia similis''.
Predation
There have been numerous recorded instances of killer whales preying on or attacking common minke whales in places such as the
Kamchatka Peninsula
The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and we ...
, Alaska, British Columbia, Washington State, California, the Gulf of St. Lawrence, Greenland, and Svalbard. They are normally able to outpace pursuing killer whales in open water or are trapped in a bay, where they are rammed and drowned or strand and die – in one instance a minke whale was able to refloat itself on the rising tide and swim away. Chases usually last about 30 minutes to an hour and can reach speeds of up , often with both species porpoising out of the water in low-angle leaps. Typically two to four killer whales and a lone minke are involved. If the pursuing killer whales do catch up to the minke it does not defend itself, which is typical of the fast-moving members of its genus. On two occasions fleeing minkes sought shelter under a boat, once off
Yakutat, Alaska
The City and Borough of Yakutat (, ;
Tlingit: ''Yaakwdáat''; russian: Якутат) is a borough
in the U.S. state of Alaska and the name of a former city within it. The name in Tlingit is ''Yaakwdáat'' (meaning "the place where canoe ...
, in 1977 and again in
Glacier Bay
Glacier Bay Basin in southeastern Alaska, in the United States, encompasses the Glacier Bay and surrounding mountains and glaciers, which was first proclaimed a U.S. National Monument on February 25, 1925, and which was later, on December 2, 1980 ...
, Alaska, in 1996 – in both instances they were attacked and killed. Killer whales typically only eat the tongue, skin, and some of the blubber of the minkes they kill.
Scavenging
Greenland shark
The Greenland shark (''Somniosus microcephalus''), also known as the gurry shark, grey shark, or by the Kalaallisut name ''eqalussuaq'', is a large shark of the family Somniosidae ("sleeper sharks"), closely related to the Pacific and souther ...
s have been found scavenging the blubber thrown overboard during Norwegian minke whaling operations off
Svalbard
Svalbard ( , ), also known as Spitsbergen, or Spitzbergen, is a Norwegian archipelago in the Arctic Ocean. North of mainland Europe, it is about midway between the northern coast of Norway and the North Pole. The islands of the group range ...
.
Great white shark
The great white shark (''Carcharodon carcharias''), also known as the white shark, white pointer, or simply great white, is a species of large mackerel shark which can be found in the coastal surface waters of all the major oceans. It is nota ...
s and
blue shark
The blue shark (''Prionace glauca''), also known as the great blue shark, is a species of requiem shark, in the family Carcharhinidae, which inhabits deep waters in the world's temperate and tropical oceans. Averaging around and preferring co ...
s have also been observed feeding on a minke whale carcass off
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
annelid
The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...
worm, '' Osedax mucofloris'', was discovered on the carcass of a 5.3 m (17.4 ft) female minke whale experimentally placed at a depth of 125 m (410 ft) in the
North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...
. This genus of worm uses
endosymbiotic
An ''endosymbiont'' or ''endobiont'' is any organism that lives within the body or cells of another organism most often, though not always, in a mutualistic relationship.
(The term endosymbiosis is from the Greek: ἔνδον ''endon'' "within ...
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
to feed on the bones of whales that fall to the seafloor.
Parasites and epibiotics
Common minke whales are a host to a number of internal and external parasites, as well as commensals, and other epibiotic fauna. Off Iceland, 45.2 per cent (85 of 188) of sampled minke whales bore old scars from attacks by the
sea lamprey
The sea lamprey (''Petromyzon marinus'') is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish".
Description
The sea lamprey has an eel-like body without paired fins. Its mouth is jawless, ro ...
''Petromyzon marinus'', while a further 10.6 per cent had fresh scars on the posterior part of their flanks; five were found with live lampreys still clinging to their flesh. The
copepod
Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...
''Caligus elongatus'' was found on 11.9 per cent of individuals, with a mean intensity (M. I.) of 95.5 per whale – the
monogenea
Monogeneans are a group of ectoparasitic flatworms commonly found on the skin, gills, or fins of fish. They have a direct lifecycle and do not require an intermediate host. Adults are hermaphrodites, meaning they have both male and female reprod ...
n
hyperparasite
A hyperparasite, also known as a metaparasite, is a parasite whose host, often an insect, is also a parasite, often specifically a parasitoid. Hyperparasites are found mainly among the wasp-waisted Apocrita within the Hymenoptera, and in two oth ...
''Udonella caligorum'' was also found attached to 22 (6.6%) of a sub-sample of 332 ''C. elongatu''s. Another copepod, ''
Pennella balaenopterae
''Pennella balaenopterae'' is a large ectoparasitic copepod specialising in parasitising marine mammals. It is the largest member of the genus ''Pennella'', the other species of which are parasites of larger marine fish.
Description
''P. ba ...
'', was found anchored into the flesh of 10.3 per cent of the whales (M. I. 1.6, with a maximum of five). The
whale louse
A whale louse is a commensal crustacean of the family Cyamidae. Despite the name, it is not a true louse (which are insects), but rather is related to the skeleton shrimp, most species of which are found in shallower waters. Whale lice are exter ...
''Cyamus balaenopterae'' was found on the skin of 6.5 per cent of the whales (M.I. 37), while the pseudo-stalked barnacle ''Xenobalanus globicipitis'' was found on the flukes of three whales (M.I. 5.3). A single individual of the
goose barnacle
Goose barnacles, also called stalked barnacles or gooseneck barnacles, are filter-feeding crustaceans that live attached to hard surfaces of rocks and flotsam in the ocean intertidal zone. Goose barnacles formerly made up the taxonomic order P ...
''
Conchoderma
''Conchoderma'' is a genus of goose barnacles in the family Lepadidae
Lepadidae is a family of goose barnacles, erected by Charles Darwin in 1852. There are about five genera and more than 20 described species in Lepadidae.
Genera
These gene ...
auritum'' was found attached to a baleen plate that belonged to a male caught off the northwest coast in 2005, while four ''C. virgatum'' were found attached to a specimen of ''P. balaenopterae'' on a female caught off the north coast in 2003.
In the St. Lawrence Estuary of eastern Canada, sea lampreys (''P. marinus'') were seen on 47 individually identified minke whales on over 100 occasions between 1999 and 2004. They were seen on the whales from June to October, with peak sightings in July and August. Between one and four lampreys were found per whale; the majority were attached below or behind the dorsal fin. On eighteen occasions, the same whale was seen multiple times with one or more lampreys attached to the same spot on its body from two to 87 days with an average of fifteen days. Twice whales were seen right after a lamprey had detached from them, revealing a bloody lesion that showed that the lampreys were feeding on their blood. On several occasions scrapes were seen on the whales from lampreys moving about their bodies probably "actively seeking areas of greater access to blood or decreased water flow".
Among a sample of 100 minke whales caught in the western North Pacific in 1995, 78% had the copepod ''P. balaenopterae'' anchored into their skin and blubber – the goose barnacle ''C. virgatum'' was found attached to ''P. balaenopterae'' on three of the whales. The whale louse ''C. balaenopterae'' was found on the skin of four whales, while a single whale had the pseudo-stalked barnacle ''X. globicipitis'' attached to its skin. All individuals sampled were infected with the
nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
''
Anisakis
''Anisakis'' (a·nuh·saa·keez)
is a genus of parasitic nematodes that have life cycles involving fish and marine mammals. They are infective to humans and cause anisakiasis. People who produce immunoglobulin E in response to this parasite ...
simplex'' in their stomachs (sometimes their small intestine) and the
acanthocephala
Acanthocephala (Greek , ', thorn + , ', head) is a phylum of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to p ...
n '' Bolbosoma nipponicum'' in their small intestine. Other internal parasites included the
cestodes
Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of man ...
'' Diphyllobothrium macroovatum'', ''Diplogonoporus balaenopterae'', and ''Tetrabothius sp.'', which infected the small intestine and were found in 17 per cent of the sample (all three species combined).
In the eastern North Pacific, forty-three of forty-four individually identified minke whales possessed what were believed to be scars from
cookiecutter shark
The cookiecutter shark (''Isistius brasiliensis''), also called the cigar shark, is a species of small squaliform shark in the family Dalatiidae. This shark occurs in warm, oceanic waters worldwide, particularly near islands, and has been rec ...
s, while three had individuals of the commensal barnacle ''Xenobalanus globicipitis'' attached to their dorsal fins. Both are primarily warm water species and may be evidence of migration for minke whales from British Columbia to tropical waters.
An immature male dwarf minke whale that stranded on the
Banks Peninsula
Banks Peninsula is a peninsula of volcanic origin on the east coast of the South Island of New Zealand. It has an area of approximately and encompasses two large harbours and many smaller bays and coves. The South Island's largest cit ...
,
South Island
The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...
, New Zealand, had a stomach heavily infested with the nematode ''Anisakis'' and cysts of the cestode genus ''Phyllobothrium'' encased in the boundary between its blubber and muscle, while an immature male caught in a gillnet off southern Brazil had a stomach heavily infested with nematodes of the genera ''Pseudoterranova'' (about 97%) and ''Anisakis'' (about 3%).
Behavior
Group size
Common minke whales are normally seen singly. In the San Juan Islands, although up to six whales could be seen in a feeding area at once they usually acted independently, with no indications of cooperative feeding like that observed in their larger relatives the humpback and
fin whale
The fin whale (''Balaenoptera physalus''), also known as finback whale or common rorqual and formerly known as herring whale or razorback whale, is a cetacean belonging to the parvorder of baleen whales. It is the second-longest species of cet ...
. On occasion, two whales could be seen surfacing at the same time, within one or two body lengths of each other – such associations could last for only one surfacing to as long as about 90 minutes. Only once were three individuals seen together for a couple surfacings. In the Monterey Bay area, usually only one whale was visible at a time; on only four occasions were two whales seen swimming together. On several occasions in the
Johnstone Strait
, image = Pacific Ranges over Johnstone Strait.jpg
, image_size = 250px
, alt =
, caption = Johnstone Strait backdropped by the Vancouver Island Ranges
, image_bathymetry = Carte baie Knight ...
area pairs and trios were briefly seen surfacing together. Around the Isle of Mull, about 68 per cent of the sightings involved single whales, 26.5 per cent involved two or three whales, while only 5.4 per cent involved groups of four to ten. Off Western Greenland and in the Gulf of St. Lawrence and southern
Gulf of Maine
The Gulf of Maine is a large gulf of the Atlantic Ocean on the east coast of North America. It is bounded by Cape Cod at the eastern tip of Massachusetts in the southwest and by Cape Sable Island at the southern tip of Nova Scotia in the northeast ...
, almost all sightings involved single whales. Off Iceland, the majority of sightings (93%) were of lone whales, with only a minority of the encounters including pairs (4%) or trios (less than 3%). Cow-calf pairs were absent from most of these regions – a single cow-calf pair was seen off the Isle of Mull in 1992, while only three were seen in the southern Gulf of Maine (in May, August, and October). Of 89 sightings in the Okhotsk Sea and Northwest Pacific, 80 were of solitary whales, seven of pairs, and one each involved groups of four and five whales.
Northern minke whales occasionally breach, sometimes completely clearing the water – one individual in the Johnstone Strait area reacted to the approach of foraging
killer whale
The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus ''Orcinus'' and is recognizable by its black-and-white pa ...
s by breaching eight times in rapid succession.
All of the dwarf minke whales caught off South Africa were taken singly. The majority of sightings of dwarf minke whales on the
Great Barrier Reef
The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...
involved either single whales (53.3%) or pairs (28.9%), with the maximum number of individuals in a group being eight. Four cow-calf pairs were seen as well. Individuals encountered on the various reef systems there often approached dive boats and circled them as well as the divers in the water. They were also seen breaching. Off Brazil, groups normally only consisted of one or two individuals, which actively avoided whale watching boats and fishing vessels. Here they were seen to associate with feeding flocks of seabirds, usually
brown boobies
The brown booby (''Sula leucogaster'') is a large seabird of the booby family Sulidae, of which it is perhaps the most common and widespread species. It has a pantropical range, which overlaps with that of other booby species. The gregarious brow ...
but also
kelp gull
The kelp gull (''Larus dominicanus''), also known as the Dominican gull, is a gull that breeds on coasts and islands through much of the Southern Hemisphere. The nominate ''L. d. dominicanus'' is the subspecies found around South America, part ...
s and
tern
Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of e ...
s on occasion.
Segregation
Common minke whales exhibit a great degree of spatial and temporal segregation by sex, age, and reproductive condition. Off Greenland, females dominate on the west coast (comprising 68% of individuals), while males predominate off the east coast (57%). On the west coast, the proportion of females in offshore waters increases with latitude, being lowest in the south (less than 40% from 60 to 63°N) and highest north of 70°N (over 90%). Females dominate during the spring and early summer (comprising nearly 79% of individuals from May to July), while the percentage of males increases from 38 to 45 per cent in the late summer (August to September). In coastal waters, the highest incidence of females occurs in the spring (about 85%), declines in the summer (72%), and rises again in the fall (over 75%). Over 70 per cent of the females in offshore waters are mature, nearly all of them pregnant (94.4%).
Off Iceland, males dominate in most areas (particularly off the southwest coast, where they comprise 70% of individuals), while females form the slight majority (53%) on the east coast. Females dominate in the spring in most areas (61%), while males predominate in the summer (58%) and fall (66%).Hauksson, E., Víkingsson, G., and Sigurjónsson, J. (2013). "Geographic, temporal and size segregation of sexes of the common minke whale (''Balaenoptera acutorostrata'') in Icelandic waters based on catch data from 1974 to 2009". ''Paper'' SC/F13/SP14 ''presented at the International Whaling Commission's Icelandic Special Meeting'', pp. 1-13. In the northeastern North Atlantic, females dominate around the Svalbard archipelago and in the Barents Sea (62.2 to 73.9%), while males predominate around the
British Isles
The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...
and off Norway (54.3 to 68.1%). Larger individuals of both sexes primarily occur further north (off Svalbard and in the Barents Sea), while smaller individuals mainly occur to the south (e.g. along the Norwegian coast from
Lofoten
Lofoten () is an archipelago and a traditional district in the county of Nordland, Norway. Lofoten has distinctive scenery with dramatic mountains and peaks, open sea and sheltered bays, beaches and untouched lands. There are two towns, Svolvær ...
south, in an area once known as a summering ground for newly weaned calves). In the Barents Sea, over 40 per cent of females are mature, with the vast majority being pregnant (94.4%).
In the western North Pacific, larger animals are typically found in higher latitudes (e.g. in the Okhotsk Sea, south of the Kuril Islands, and around the
Commander
Commander (commonly abbreviated as Cmdr.) is a common naval officer rank. Commander is also used as a rank or title in other formal organizations, including several police forces. In several countries this naval rank is termed frigate captain.
...
and western
Aleutian Islands
The Aleutian Islands (; ; ale, Unangam Tanangin,”Land of the Aleuts", possibly from Chukchi language, Chukchi ''aliat'', "island"), also called the Aleut Islands or Aleutic Islands and known before 1867 as the Catherine Archipelago, are a cha ...
), while smaller animals, especially females, dominate in lower latitudes (e.g. off
Sanriku
, sometimes known as , lies on the northeastern side of the island of Honshu, corresponding to today's Aomori, Iwate and parts of Miyagi Prefecture and has a long history.
The 36 bays of this irregular coastline tend to amplify the destructivenes ...
). The percentage of mature females is high in offshore areas (72.5 to 86.7%), with most of them being pregnant (85.7 to 100%). In coastal areas, however, most females are immature (60.4 to 94.2%) and fewer of the mature females are pregnant (40 to 58.4%). Females dominate in the northern Yellow Sea (90.9%) and off the east coast of
North Korea
North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korea, Korean Peninsula and shares borders with China and Russia to the north, at the Yalu River, Y ...
(69.2%), while males predominate off the west coast of Honshu (72.6%) and off the southwest and west coasts of Hokkaido (90.5 and 59.7%). In the southern Okhotsk Sea, females arrive earlier than males (April and May, respectively), while mature females arrive earlier than immature ones.
Surfacing sequence
When a minke whale first comes to the surface to breathe its pointed rostrum is the first to break the surface. It either exhales beforehand or a narrow, diffuse blow or a low, bushy, diffuse blow is visible. It then arches its back in a quick motion, exaggerating this arch during its terminal deep dive. Often the blowholes and dorsal fin are visible at the same time. Depending on its behavior, it may exhale anywhere from one to seven times in rapid succession before going on a longer dive of several minutes duration. In the Gulf of St. Lawrence, this depended on whether a whale was traveling, searching, or feeding. During traveling, when the whale was slower moving (generally in a straight line), it would exhale the greatest number of times (6.44 on average) and dive for a longer period of time (3.67 minutes on average) than when it was feeding, which was characterized by constant change in direction and vigorous swimming – this normally involved one or two respirations interspersed with three to seven (2.27 on average) followed by a relatively short dive (1.36 minutes on average). When a whale was searching, on the other hand (which involved the whale moving at a faster speed than traveling in a sort of zigzag motion), it would exhale 3.22 times on average and dive the longest of the three modes (3.76 minutes on average).
In the Monterey Bay area, focal follows of minke whales showed that they respired an average of 3.74 times during a surfacing sequence. These short duration dives averaged 37.8 seconds and were followed by a long duration dive of an average of 4.43 minutes. In the San Juan Islands, the number of exhalations and the duration of dives depended on whether the whale was lunge feeding or feeding with birds. In the former method of feeding, whales made short dives – about 22 seconds long – up to seven times in rapid succession before making a long dive of about 3.8 minutes, while during the latter method they made longer short dives of about 65 seconds followed by shorter long dives of about 1.5 minutes.
Feeding techniques
In the Gulf of St. Lawrence, minke whales exhibit three types of behaviors: entrapment maneuvers, engulfment maneuvers, and entrapment/engulfment maneuvers. Entrapment maneuvers include circles, gyres, ellipses, figure-of-eights, and hyperbolas. ''Circles'' involve a whale, lying on its side with its ventral surface facing its intended prey, swimming in a circle 1.5 to 2.5 times its diameter and lunging mouth agape across the diameter of this circle. As the whale mounts the water column the movement of its flukes create a print or trace. ''Gyres'' are larger versions of circles that steadily decrease in diameter as the whale performs each circuit. ''Ellipses'' cover a greater area than the former two maneuvers as the whale swims a long and short axis – the former can be greater than at times. Ellipses can be maintained for long periods of time and may include feeding circles within them as well as a number of engulfing maneuvers. Unlike circles, surface traces are rarely apparent. ''Figure-of-eights'' are smaller versions of ellipses, with a long axis of less than six body lengths. The whale turns in opposite directions at each end of the long axis. ''Hyperbolas'' involve the whale turning at least once at the end of a short straight line run – this maneuver is sometimes performed alongside a rock face, followed by an inward facing feeding lunge.
Engulfment maneuvers include plunges, oblique, lateral, vertical and ventral lunges. During ''plunges'' the whale approaches the water at an angle of less than 30° with its ventral surface facing downwards. Usually only the rostrum and part of the lower lip are visible above the surface of the water as it breaks the surface and often the tops of the extended ventral pleats. ''Oblique lunges'' are executed at a greater angle (about 45°) and entirely expose the extended ventral pleats; at times the entire body exits the water in a low, porpoising-like breach. During a ''lateral lunge'' the whale breaks the surface on its side, while during ''vertical'' and ''ventral lunges'' the whale exits the water at a 90° angle and while on its back, respectively.
Entrapment/engulfment maneuvers include horizontal, lateral and ventral arcs. During a ''horizontal arc'' a whale turns sharply – on either side – with only a pectoral fin or occasionally a tip of the flukes breaking the surface of the water. ''Lateral'' and ''ventral arcs'' are similar to lateral and ventral lunges, but without any part of the whale breaking the surface of the water. All three of these maneuvers have been observed with both expanded and unexpanded ventral pleats.
Plunges were used the most often (22% of the time), followed by ventral (19%), lateral (17%), and oblique lunges (15%). Vertical lunges were infrequently utilized (only 5% of the time), as were horizontal (7%), ventral (6%), and lateral arcs (3%).
Novel feeding techniques were observed during a study of five individually identified minke whales (named M1 to M5) in the
Saguenay Fjord National Park
Saguenay Fjord National Park (french: parc national du Fjord-du-Saguenay) is a provincial park located in Quebec, Canada. In the regions of Saguenay–Lac-Saint-Jean, Charlevoix, Côte-Nord, and Bas-Saint-Laurent, the park is situated along the ...
, on the north side of the St. Lawrence estuary, from June to October 2003. These maneuvers included head slaps, chip-up blows, and exhales on the dive. During a ''head slap'', the whale would raise its head high out of the water at angle of about 30 to 45°, take a quick breath, and then slam its head onto the water, creating a loud splash. It would do this without expanding its ventral pleats or forcing water out of its mouth. After doing several head slaps the whale would perform a feeding lunge. Head slaps were used almost exclusively by M4 and M5. A ''chin-up blow'' is similar to a normal surfacing but more energetic and executed at a greater angle as the whale comes high out of the water to breathe and dive again in one continuous motion without slapping the surface of the water. Chin-up blows were utilized often and performed by all five whales; it was the principal technique used by M1, M2, and M3 prior to a feeding lunge. An ''exhale on the dive'' is exactly what its name implies: a whale exhaling as its blowholes submerge. This resulted in a large volume of water being displaced and typically followed a normal blow or a chin-up blow and on occasion a head slap. This technique was only executed by M1 and M5. These new techniques are thought to have been developed by these whales to help them herd small schooling fish (likely capelin) in the well-mixed waters of the Saguenay Fjord; these tactics were not observed in the nearby
Laurentian Channel
The Laurentian Channel is a deep submarine valley off the coast of eastern Canada in the Gulf of Saint Lawrence.
The channel is of glacial origin and is the submerged valley of the historic Saint Lawrence River, running from a sharp escarpment ...
Head, where "strong tidal currents, a stratified water column and bottom topography combine to create large areas of upwelling in which prey are forced to the surface".
In July 2007, a minke whale with what appeared to be a rope injury was observed surface feeding on capelin in the Gulf of St. Lawrence. The long, linear laceration extended around the ventral pleats, restricting their distention. This individual performed a number of oblique lunges on its right side and then rotated in mid-air to the left, landing upright on its rostrum. This was not observed in any of the other feeding whales. This may have been done to avoid landing on the injured portion of its ventral pleats.
Vocalizations
North Atlantic
In the North Atlantic, minke whales produce downsweeps and "pulse" or "thump trains". Downsweeps, which last 0.4 seconds in duration and sweep down from 100-200 Hz (median: 118 Hz) to below 90 Hz (median: 80 Hz) have been recorded in the St. Lawrence estuary of eastern Canada.Edds-Walton, P. L. (2000). "Vocalisations of minke whales ''Balaenoptera acutorostrata'' in the St. Lawrence estuary". ''Bioacoustics'' 11 (1): 31-50 (abstract only). Pulse trains have been recorded off
Puerto Rico
Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...
and in
Massachusetts Bay
Massachusetts Bay is a bay on the Gulf of Maine that forms part of the central coastline of the Commonwealth of Massachusetts.
Description
The bay extends from Cape Ann on the north to Plymouth Harbor on the south, a distance of about . Its ...
. Two types, "speed-up" and "slow-down", were recorded off Puerto Rico, while the same two calls as well as a "constant" call, were recorded in Massachusetts Bay. They differ in pulse rate, peak
frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...
, and duration. In the latter area, slow-down was the most commonly recorded type. Their peak frequencies ranged from 58 to 136 Hz and each pulse lasted from 0.07 to 0.12 seconds, together producing pulse trains of 12.4 to 39.8 seconds in duration. Detections of pulse trains peaked during August and September, with most calls being heard from mid-July to mid-November. None were recorded in January and February and few were detected from March to June. The pulse trains off Puerto Rico were recorded in March.Mellinger, D. K., Carson, C. D., and Clark, C. W. (2000). "Characteristics of minke whale (''Balaenoptera acutorostrata'') pulse trains recorded near Puerto Rico". ''Marine Mammal Science'' 16 (4): 739-756 (abstract only).
North Pacific
In the North Pacific, what were called "boings" was first described in the mid-1960s from
submarine
A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...
recordings made off
San Diego
San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the List of United States cities by population, eigh ...
, California, and Kaneohe, Hawaii, in the 1950s. They consist of a brief pulse – called a ''precursor'' – with a duration of 0.28 seconds (range: 0.15 to 1.6 seconds) followed by a
frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...
and
amplitude modulated
Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the amplitude (signal strength) of the wave is varied in proportion to t ...
long call – called the ''AM component'' – of 2.2 seconds duration (range: 1.4 to 4.2 seconds). Both had peak frequencies of 1.4
kHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that on ...
with
harmonic
A harmonic is a wave with a frequency that is a positive integer multiple of the ''fundamental frequency'', the frequency of the original periodic signal, such as a sinusoidal wave. The original signal is also called the ''1st harmonic'', the ...
s of up to 9 kHz. These strange calls were recorded from October to May – peaking in March – and had a source level of about 150
decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a po ...
s with reference to one
micropascal
The pascal (symbol: Pa) is the unit of pressure in the International System of Units (SI), and is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is defined a ...
metre
The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its pref ...
. Their source remained a mystery for decades. By the early 1980s they were thought to come from whales, but it wasn't known what species. In the early 2000s, it was suggested these sounds might originate from minke whales, based on their similarities to vocalizations produced by Southern Hemisphere forms. Finally, during a 2002 HICEAS (''H''awaiian ''I''slands ''C''etacean and ''E''cosystem ''A''ssessment ''S''urvey) survey, the R/V ''David Starr Jordan'', using a towed
hydrophone
A hydrophone ( grc, ὕδωρ + φωνή, , water + sound) is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates an electric potenti ...
array, detected boings off the northwestern Hawaiian Islands on 7 November 2002 and discovered they came from a minke whale, which they photographed and biopsied.
Boings have been divided into two types: the ''central boing'' and the ''eastern boing''. The former has only been recorded west of 135°W, while the latter has only been recorded east of 138°W. They differ in pulse repetition rate and total duration. There may also be a "western boing" off Japan. Most boings have been recorded in the tropical and warm temperate North Pacific during the winter and spring, but some have also been detected in the northeastern Chukchi Sea in the summer and fall.
Southern Hemisphere
The "star wars" vocalization, a complex, stereotyped call consisting of three components ranging from 50 Hz to 9.4 kHz, is produced by the dwarf minke whale. It has a source level of 150 to 165 decibels at a reference pressure of one micropascal at one metre. This bizarre call, described as "almost synthetic, metallic, or mechanical", has been recorded during June and July on the northern Great Barrier Reef (about 14°30'S to 17°S), off
Stradbroke Island
Stradbroke Island, also known as Minjerribah, was a large sand island that formed much of the eastern side of Moreton Bay near Brisbane, Queensland until the late 19th century. Today the island is split into two islands: North Stradbroke Islan ...
, Queensland (27°30'S), and off
Coffs Harbour
Coffs Harbour is a city on the Mid North Coast of New South Wales, Australia, north of Sydney, and south of Brisbane. It is one of the largest urban centres on the North Coast, with a population of 78,759 as per 2021 census. The Gumbaynggirr ...
, New South Wales ( 30°S). They also produce downswept calls of 250 to 50 Hz.
Whaling
North Atlantic
The first written records attest to the active hunting of minke whales off Norway by 1100 A.D. By 1240 they began utilizing iron darts fired from crossbows that had been treated with the tissue of dead sheep infected with the bacterium '' Clostridium''. Introducing this infectious agent to a wound weakened the whale and after a couple days the men would return and lance it to death. This method of whaling continued to be used until the 1880s.Chadwick, Douglas H. (2008). ''The grandest of lives: eye to eye with whales''. Berkeley, CA: Counterpoint.
Norwegian catching of minke whales from small fishing vessels started off Møre, western Norway, in the 1920s. It had spread north to
Salten
Salten is a traditional district in Nordland county, Norway. It includes the municipalities of Meløy, Gildeskål, Bodø, Beiarn, Saltdal, Fauske, Sørfold, Steigen, and Hamarøy. Salten covers an area of about and has a population (2016) ...
by 1932 and all along the Norwegian coast and to Bear Island,
Spitsbergen
Spitsbergen (; formerly known as West Spitsbergen; Norwegian: ''Vest Spitsbergen'' or ''Vestspitsbergen'' , also sometimes spelled Spitzbergen) is the largest and the only permanently populated island of the Svalbard archipelago in northern Norw ...
, and the
Barents Sea
The Barents Sea ( , also ; no, Barentshavet, ; russian: Баренцево море, Barentsevo More) is a marginal sea of the Arctic Ocean, located off the northern coasts of Norway and Russia and divided between Norwegian and Russian territo ...
by the late 1930s – the latter area, particularly the southeastern region east to Novaya Zemlya, was one of the most important whaling grounds, with over 2,400 whales being caught there in 1949. Licenses were introduced in 1938. A westward expansion to the waters north and east of Iceland occurred; by 1966 they had reached the
Denmark Strait
The Denmark Strait () or Greenland Strait ( , 'Greenland Sound') is an oceanic strait between Greenland to its northwest and Iceland to its southeast. The Norwegian island of Jan Mayen lies northeast of the strait.
Geography
The strait connect ...
and western Greenland just two years later. At its peak over 300 vessels participated in the hunt each season, but this declined to about 50 in the 1980s. By the end of the Second World War the catch was at nearly 2,000 per annum, peaked at 4,338 in 1958, and declined to 2,307 by 1970. Over 125,000 have been caught by Norwegian commercial whaling since 1938. In accordance with the moratorium against commercial whaling voted on by the
International Whaling Commission
The International Whaling Commission (IWC) is a specialised regional fishery management organisation, established under the terms of the 1946 International Convention for the Regulation of Whaling (ICRW) to "provide for the proper conservation of ...
in 1982 and taking effect in 1986, commercial catches ceased in 1987 (albeit only temporarily). From 1988 to 1990 and again from 1992 to 1994 Norway caught minke whales under scientific permit and resumed commercial whaling of the species in 1993. They typically catch 450 to 600 individuals a year, with 464 being taken in 2012.
Minke whales were first caught off Iceland in 1914 by the powered 4-ton fishing vessel ''Margrét IS 314'', which was mounted with a 1.5 inch bore harpoon gun – this was replaced in 1923 with a 2-inch bore harpoon gun manufactured in Norway. Later other vessels joined the trade. Operations were limited to coastal waters, normally within 30 nautical miles of shore. The season extended from the beginning of March to late November, even to early December at times; though most were caught between April and October. They were mainly caught for their meat, with a minimum of 3,362 being taken between 1914 and 1980. Catch limits were introduced in 1977. The average annual catch rose from 105 from 1966 to 1970, to 137 from 1971–1975, and finally to 200 from 1976 to 1980. The last were caught in 1985 before whaling resumed in 2003 under scientific permit, with 200 being taken from 2003 to 2007. Commercial whaling for minkes was renewed in 2006, with a total catch of 296 between 2006 and 2012.
A Newfoundland whaling company began catching "little piked whales" (minke whales) off northeastern Newfoundland in 1947, taking 16 in its first year and 41 in 1948. A total of 812 minke whales were caught off Newfoundland between 1947 and 1972, with a peak of 97 in 1972. They were captured by one to three wood-hulled vessels that had a 50 mm harpoon cannon mounted on their bows. Whales were towed to a shore station for flensing. They were first caught in Conception, Bonavista, and Trinity bays, but later catches (1966 to 1972) were mainly made in Trinity Bay itself. The season extended from May to September (rarely October), with peak catches being made in June and July. A small number – 51 between 1962 and 1967 – were also caught off
Nova Scotia
Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland".
Most of the population are native Eng ...
, with the season lasting from June to August.
Minke whales were first exploited by Greenlanders off western Greenland in 1948, when a fishing vessel mounted with a harpoon cannon began catching them. This vessel averaged 18 whales per annum (range four to 32), before being joined by three other vessels in 1958. The number of vessels participating in the hunt each year increased rapidly, rising from 18 in 1963, to 25 in 1964, and to 45 in 1965. The peak was reached in 1968 and 1969, with 56 vessels active in both years. From 1970 to 1976 the average fluctuated between about 30 and 45 vessels. A total of 3,434 minke whales were taken off western Greenland between 1948 and 1976, with a peak of 315 reached in 1968. The vast majority of these whales were taken by fishing vessels normally targeting cod,
shrimp
Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...
, or
salmon
Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...
, but an increasing number in later years were caught using a number of small boats with out-board motors, armed with high-powered rifles for killing the whale and hand-held harpoons and floating bladders to secure them; walkie-talkies were used for coordination. Usage of this method, called a "collective catch", increased from a catch of just one whale in 1970 to 59 in 1975.
In southwest Greenland (south of 66°15'N), the season lasts from April to November, with peaks in May and October. Occasionally a few whales are caught in the winter. On the central west coast (
Disko Bay
Disko Bay ( kl, Qeqertarsuup tunua; da, DiskobugtenChristensen, N.O. & al.Elections in Greenland. ''Arctic Circular'', Vol. 4 (1951), pp. 83–85. Op. cit. "Northern News". ''Arctic'', Vol. 5, No. 1 (Mar 1952), pp. 58–59.) is a large ...
and adjacent areas from 66°15'N to 70°45'N), the season begins in late May and peaks in July, August or September. In some years, mild ice-less winters also allow catching in this region from November to April. In the northwest (mainly the
Umanak
Uummannaq is a town in the Avannaata municipality, in central-western Greenland. With 1,407 inhabitants in 2020, it is the eighth-largest town in Greenland, and is home to the country's most northerly ferry terminal. Founded in 1763 as Omenak, t ...
district, 70°45'N to 73- 74°N), the season doesn't begin until June because of sea ice, with peak catches occurring from July to September. A few are also caught in October and November. Minke whales were caught for their meat, with it mainly being used locally for human consumption and dog food, though in Umanak the
Royal Greenland Trading Department
The Royal Greenland Trading Department ( da, Den Kongelige Grønlandske Handel, KGH) was a Danish state enterprise charged with administering the realm's settlements and trade in Greenland. The company managed the government of Greenland from 177 ...
purchased some of the products of the hunt beginning in the late 1960s. An additional 4,307 minke whales were caught off Greenland between 1985 and 2012, 4,070 off western Greenland and a paltry 237 off eastern Greenland. The average annual catch during this period has usually been between 150 and 190 whales.
A total of 97 were caught off the
Faroe Islands
The Faroe Islands ( ), or simply the Faroes ( fo, Føroyar ; da, Færøerne ), are a North Atlantic island group and an autonomous territory of the Kingdom of Denmark.
They are located north-northwest of Scotland, and about halfway bet ...
between 1960 and 1971, with a peak of 32 in 1968. One was also taken off Portugal in 1951.
North Pacific
There is no evidence minke whales were caught in Japan during the harpoon and net whaling eras. The small-type catcher boat ''Yuko-maru 7'' GRT caught the first minkes out of Akukawa in 1930. In the first half of the 1930s, about 20-30 was taken per year out of this port. Minke whaling soon spread to the port of
Kamaishi
is a city located on the Sanriku rias coast in Iwate Prefecture, Japan. , the city had an estimated population of 32,609, and a population density of 74 persons per km2, in 16,230 households. The total area of the city is
Geography
Kamaishi ...
(1938), on the northeast coast of
Honshu
, historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separ ...
Kyushu
is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surroun ...
; and to Wakasa Bay and
Aomori
is the capital city of Aomori Prefecture, in the Tōhoku region of Japan. , the city had an estimated population of 278,964 in 136,457 households, and a population density of 340 people per square kilometer spread over the city's total area of ...
(both by 1957), the former on the west coast and the latter on the north coast of Honshu. An average of 23 catcher boats – each of which averaged about 23 tons between 1952 and 1986 – were involved each year between 1950 and 1986, from a peak of 80 in 1950 to a low of seven from 1973 to 1978 – these boats also caught other species, mainly
giant beaked whale
The four-toothed whales or giant beaked whales are beaked whales in the genus ''Berardius''. They include Arnoux's beaked whale (''Berardius arnuxii'') in cold Southern Hemispheric waters, and Baird's beaked whale (''Berardius bairdii'') in t ...
s,
short-finned pilot whale
The short-finned pilot whale (''Globicephala macrorhynchus'') is one of the two species of cetaceans in the genus '' Globicephala'', which it shares with the long-finned pilot whale (''G. melas''). It is part of the oceanic dolphin family (Del ...
s, and
killer whale
The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus ''Orcinus'' and is recognizable by its black-and-white pa ...
s. As the number of boats declined the average tonnage increased dramatically, from 14.6 in 1952 to 39 in 1982. In 1979, nine catchers averaged about 360 horsepower – they ranged from 15.2 tons and 150 horsepower for the tiny ''Katsu Maru'' (1978–1986) to the 36.99-ton ''Koei Maru No. 7'' at 450 horsepower. The largest was the 47.77-ton ''Sumitomo Maru No. 31'', which operated from 1982 to 1986. These vessels used harpoon guns of 50 mm caliber or less. Because of their small size, limited cruising range, and inability to work during inclement weather, catchers were restricted to within 50 nautical miles of their home port in the 1950s, while the vast majority operated within 80 nautical miles of their home ports or designated unloading ports (for Hokkaido) during the period 1977 to 1987. In 1968 small motorboats were introduced, which scared the whales into swimming quickly at the surface, making them easier to track and exhausting them in the process – this allowed them to be more easily killed as well. The earliest were long and 2 tons with 65-80 horsepower outboard engines; later boats with 165 horsepower were utilized. The number of catchers using motorboats increased rapidly from 1968 to 1972; by 1979 they all used them.
Several hundred minkes were caught each year, with the peak being reached in 1956, when 532 were taken. A total of 13,334 were taken by Japanese coastal whaling between 1948 and 1987. Most were caught off
Sanriku
, sometimes known as , lies on the northeastern side of the island of Honshu, corresponding to today's Aomori, Iwate and parts of Miyagi Prefecture and has a long history.
The 36 bays of this irregular coastline tend to amplify the destructivenes ...
and on the
Okhotsk Sea
The Sea of Okhotsk ( rus, Охо́тское мо́ре, Ohótskoye móre ; ja, オホーツク海, Ohōtsuku-kai) is a marginal sea of the western Pacific Ocean. It is located between Russia's Kamchatka Peninsula on the east, the Kuril Islands ...
side of
Hokkaido
is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel.
The la ...
, with the Pacific side of Hokkaido gaining some importance by the early 1970s. They were seldom caught off the west coast of Honshu (off Tottori, in Tsuruga Bay, and
Toyama Bay
is a bay located on the northern shores of the Hokuriku region of Honshu, Japan on the Sea of Japan. The bay borders Toyama and Ishikawa prefectures. The bay is known for the mirages on the horizon during the winter months and for being a spaw ...
), which was abandoned by the mid-1970s. Few were taken on the
Sea of Japan
The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it h ...
side of Hokkaido as well. They were formerly captured off western Kyushu and the south coasts of Honshu and
Shikoku
is the smallest of the four main islands of Japan. It is long and between wide. It has a population of 3.8 million (, 3.1%). It is south of Honshu and northeast of Kyushu. Shikoku's ancient names include ''Iyo-no-futana-shima'' (), '' ...
, but catching in those regions ceased by 1965 due to the scarcity of whales. The first minkes of the season were caught off western Kyushu and the Sea of Japan side of Honshu, where peak catches occurred from March to May and March to April, respectively; from there effort shifted to the Okhotsk Sea side of Hokkaido and Sanriku, where catches peaked in May for the former area and from April to May in the latter area. Effort was finally diverted to the Pacific side of Hokkaido, where peak catches were made from July to September. The season as a whole extended from February to October.
In 1973 a duel factory-catcher boat was built, the ''Miwa Maru'', which caught 279 minke whales from 1973 to 1975, mainly in the Okhotsk Sea. Japanese pelagic fleets also caught six in the
Gulf of Alaska
The Gulf of Alaska (Tlingit: ''Yéil T'ooch’'') is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, ...
, four in 1964 and two in 1971; an additional 22 were taken by pelagic fleets in the western North Pacific and western
Bering Sea
The Bering Sea (, ; rus, Бе́рингово мо́ре, r=Béringovo móre) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and The Ameri ...
in 1969, 1970, and 1976 – the last, a immature female taken at , was a special permit catch.
Commercial catches ended in 1987. In 1994, Japan began catching minke whales in the western North Pacific under scientific permit. Under the title of JARPN (Japanese Whale Research Program under Special Permit in the North Pacific), up to 100 whales were caught each year by a pelagic fleet consisting of the 7,198 to 7,575 gross ton factory ship ''
Nisshin Maru
The is the primary vessel of the Japanese whaling fleet and is the world's only whaler factory ship. It was the research base ship for the Institute of Cetacean Research for 2002 to 2007. It has a tonnage of and is the largest member and flagshi ...
'' and two to three sighting/sampling vessels – including ''Toshi Maru No. 25'' (739.92 gross tons, 1994–1999), ''Toshi Maru No. 18'' (758.33 gross tons, 1994–1998), ''Kyo Maru No. 1'' (812.08 gross tons, 1995–1999), and ''Yushin Maru'' (720 gross tons, 1999) – until 1999. A total of 498 minke whales were caught.Fujise, Y., Kishiro, T., Zenitani, R., Matsuoka, K., Kawasaki, M., and Shimamoto, K. (1995). "Cruise report of the Japanese whale research program under a special permit for North Pacific minke whales in 1994". ''Paper'' SC/47/NP3 ''presented to the IWC Scientific Committee''.Fujise, Y., Iwasaki, T., Zenitani, R., Araki, J., Matsuoka, K., Tamura, T., Aono, S., Yoshida, T., Hidaka, H., Nibe, T., and Tohyama, D. (1996). "Cruise report of the Japanese Whale Research Program under a Special Permit for North Pacific minke whales in 1995 with the results of a preliminary analysis of data collected". ''Paper'' SC/48/Np13 ''presented to the IWC Scientific Committee''.Fujise, Y., Shimada, H., Zenitani, R., Goto, M., Tamura, T., Lindstrom, U., Uchida, A., Yoshida, H., Shimamoto, K., Yuzu, S., Kasai, H., Kinoshita, T., Iwata, T., and Toyama, D. (1997). "Cruise report of the Japanese Whale Research Program under a Special Permit in the North Pacific (JARPN) in 1996 with some preliminary analysis of data collected during the 1994–1996 JARPN surveys". ''Paper'' SC/49/NP8 ''presented to the IWC Scientific Committee''.Ishikawa, H., Yuzu, S., Shimamoto, K., Bando, T., Ohshima, K., Kasai, H., Kinoshita, T., Mizushima, Y., Iwakami, H., Nibe, T., Hosoyama, T., Kuramochi, T., Numano, K., and Miyamoto, M. (1997). "Cruise report of the Japanese Whale Research Program under a Special Permit in the North Pacific (JARPN) in 1997". ''Paper'' SC/49/NP9 ''presented to the IWC Scientific Committee''.Zenitani, R., Fujise, Y., Matsuoka, K., Tamura, T., Bando, T., Ichihashi, H., Shimokawa, T., Krasnenko, A. S., Taguchi, F., Kinoshita, T., Mori, M., Watanabe, M., Ichinomiya, D., Nakamura, M., Sakai, K., Matsuzaka, K., Kamei, H., and Tohyama, D. (1999). "Cruise report of the Japanese Whale Research Program under a special permit in the North pacific in 1998". ''Paper'' SC/51/RMP7 ''presented to the IWC Scientific Committee''.Fujise, Y., Zenitani, R., Tamura, T., Bando, T., Ohtani, S., Takeda, S., Kitajima, A., Kimura, T., Masaki, T., and Tohyama, D. (2000). "Cruise report of the Japanese Whale Research Program under special permit in the North Pacific (JARPN) in 1999". ''Paper'' SC/F2K/J9 ''presented to the JARPN review meeting''. After a two-year feasibility study,Fujise, Y., Pastene, L. A., Tamura, T., Bando, T., Murase, H., Kawahara, S., Watanabe, H., Ohizumi, H., Mogoe, T., Kiwada, H., Nemoto, K., and Narita, H. (2001). "Progress Report of the Feasibility study of the Japanese whale research program under special permit in the western North Pacific – Phase II (JARPN II) in 2000". ''Paper'' SC/53/O10 ''presented to the IWC Scientific Committee''.Fujise, Y., Tamura, T., Bando, T., Watanabe, H., Kiwada, H., Otani, S., Kanda, N., Yasunaga, G., Mogoe, T., Konishi, K., Inamori, M., Shigemune, H., and Tohyama, D. (2002). "Cruise report of the feasibility study of the Japanese whales research program under special permit in the western North Pacific-phase II (JARPN II) in 2001". ''Paper'' SC/54/O16 ''presented to the IWC Scientific Committee''. JARPN II began in 2002,Fujise, Y., Tamura, T., Bando, T., Yasunaga, G., Konishi, K., Murase, H., Yoshida, T., Itoh, S., Ogawa, R., Sasaki, T., Fukutome, K., Isoda, T., Birukawa, N., Horji, N., Zharikov, K. A., Park, K. J., Tohyama, D., and Kawahara, S. (2003). "Cruise Report of the Japanese Whale Research Program under Special Permit in the western North Pacific – Phase II (JARPN II) in 2002 (part I) – Offshore component". ''Document'' SC/55/O7 ''submitted to the IWC Scientific Committee''. also taking up to 100 whales per year with a pelagic fleet consisting mainly of the same vessels – ''Nisshin Maru'' was enlarged to 8,030 gross tons in 2006Tamura, T., Matsuoka, K., Bando, T., Mogoe, T., Konishi, K., Mori, M., Tsunekawa, M., Okamoto, K., Funasaka, N., Sakajiri, H., Yoshida, Y., Kumagai, S., Kimura, K., Takamatsu, T., Konagai, T., Sasaki, S., Kuwaoka, J., and Ogawa, T. (2007). "Cruise Report of the second phase of the Japanese Whale Research Program under Special Permit in the Western North Pacific (JARPN II) in 2006 (part I) – Offshore component". ''Document'' SC/59/05 ''submitted to the IWC Scientific Committee''. and ''
Yūshin Maru No. 2
is a Japanese-registered whale catcher that undertakes whaling operations in the North Pacific Ocean and Southern Ocean. Along with other vessels of the Japanese whaling fleet, she has been featured on American television since 2008, in the ...
'' (747 gross tons) and '' Yūshin Maru No. 3'' (742 gross tons) replaced ''Toshi Maru No. 25'' and ''Kyo Maru No. 1'' in 2003Tamura, T., Fujise, Y., Bando, T., Yasunaga, G., Konishi, K., Kiwada, H., Isoda, T., Itoh, S., Machida, S., Tsunekawa, M., Konagai, T., Takamatsu, T., Ohshima, T., Honjo, K., Matsuoka, T., Zharikov, K. A., An, Y. R., Tohyama, D., and Kawahara, S. (2004). "Cruise Report of the Japanese Whale Research Program under Special Permit in the western North Pacific – Phase II (JARPN II) in 2003 (part I) – Offshore component". ''Document'' SC/56/O13 ''submitted to the IWC Scientific Committee''. and 2008,Tamura, T., Otani, S., Isoda, T., Wada, A., Yonezaki, S., Mori, M., Tsunekawa, M., Fukutome, K., Nakai, K., Satoh, H., Nomura, I., Nagatsuka, S., Umatani, M., Koyanagi, T., Takamatsu, T., Kawabe, S., Kandabashi, S., Watanabe, H., Kumagai, S., Sato, H., and Ogawa, T. (2009). "Cruise Report of the second phase of the Japanese Whale Research Program under Special Permit in the Western North Pacific (JARPN II) in 2008 (part I) – Offshore component". ''Paper'' SC/61/O4 ''submitted to the IWC Scientific Committee''. respectively – but expanding its operations to include a coastal component using three to four small-type sampling vessels – mainly ''Taisho Maru No. 28'' (47.31 gross tons, 2002–2012), ''Sumitomo Maru No. 31'' (32 gross tons, 2002–2010), ''Katsu Maru No. 7'' (32 gross tons, 2002–2012), and ''Koei Maru No. 75'' (46 gross tons, 2003–2010) – with a total of up to 120 individuals being caught off Sanriku in the spring and off
Kushiro
is a city in Kushiro Subprefecture on the island of Hokkaido, Japan. It serves as the subprefecture's capital and it is the most populated city in the eastern part of the island.
Geography
Mountains
* Mount Oakan
* Mount Meakan
* Mount Akan ...
, on the Pacific side of Hokkaido, in the fall.Yasunaga, G., Itoh, N., Wada, A., Kiwada, H., Sato, H., Maeda, H., Nakamura, G., Inoue, S., Miyakawa, N., Kitayama, K., Ishikawa, Y., Suzuki, N., Tsutsumi, T., Kadowaki, I., and Kato, H. (2012). "Cruise Report of the second phase of the Japanese Whale Research Program under special permit in the western North Pacific (JARPN II) in 2011 – (Part II) – Coastal component off Kushiro, spring survey". ''Paper'' SC/64/O4 ''submitted to the IWC Scientific Committee''.Yoshida, H., Ito, N., Kishiro, T., Miyashita, T., Yasunaga, G., Hara, T., Nakamura, G., Maeda, H., Inoue, S., Tsutsumi, T., Ishida, K., Tamai, N., Kadowaki, I., Oka, S., Takahashi, M., Fukumoto, A., Kumagai, S., Sato, H., Sakamoto, N., Kitayama, K., Kobayashi, N., and Kato, H. (2013). "Cruise report of the second phase of the Japanese Whale Research Program under Special Permit in the western North Pacific (JARPN II) in 2012 (Part III) – Coastal component off Kushiro". ''Paper'' SC/65a/O06 ''submitted to the IWC Scientific Committee''. This research program continues to the present.Bando, T., Mogoe, T., Isoda, T., Wada, A., Mori, M., Tsunekawa, M., Tamahashi, K., Moriyama, R., Miyakawa, N., Kadowaki, I., Watanabe, H., and Ogawa, T. (2013). "Cruise Report of the second phase of the Japanese Whale Research Program under Special Permit in the western North Pacific (JARPN II) in 2012 (part I) – Offshore component". ''Document'' SC/65a/O03 ''submitted to the IWC Scientific Committee''.
Whaling for minke whales off Korea began in the early 1930s, when they were opportunistically caught by vessels targeting larger species. The number of boats used per year ranged from 13 (1967–68, 1983–84) to 24 (1965), with 21 per annum between 1975 and 1982. Their average tonnage and horsepower increased from 56 (1971) to 74.5 tons (1982) and from about 220 (1971) to nearly 539 horsepower (1982). In 1982, they ranged from the diminutive ''Gu Pok'', only 18.3 tons and a mere 45 horsepower, to ''Tae Won'' and ''Jin Yang 5'' – each nearly 99 tons – and ''Chung Gu 1'', ''Chung Gu 2'' and ''U Seung 3'', all three with 1,000 horsepower. Minkes were permitted to be landed for flensing at the main whaling stations of
Ulsan
Ulsan (), officially the Ulsan Metropolitan City is South Korea's seventh-largest metropolitan city and the eighth-largest city overall, with a population of over 1.1 million inhabitants. It is located in the south-east of the country, neighboring ...
, on the east coast, and Ucheango, on the west coast, as well as Jukbyeon, Kuryongpo, Heusando, Daichangdo, and Cheju. By the early 1960s a few hundred were being caught each year. The catch increased from 715 in 1970, to 882 in 1973, to a peak of 1,033 and 1,018 in 1977 and 1978. Minkes were caught almost year-round (February to December), with the most important whaling ground being the central
Yellow Sea
The Yellow Sea is a marginal sea of the Western Pacific Ocean located between mainland China and the Korean Peninsula, and can be considered the northwestern part of the East China Sea. It is one of four seas named after common colour terms ...
from March to April. From there, catches extended to the
Korean Strait
The Korea Strait is a sea passage in East Asia between Korea and Japan, connecting the East China Sea, the Yellow Sea and the Sea of Japan in the northwest Pacific Ocean. The strait is split by the Tsushima Island into the Western Channel and t ...
in May and the southwestern Sea of Japan from June to October. Most were caught from April to June, with a peak in the Yellow Sea in April and in the Sea of Japan in June. They were also caught in the northern Yellow Sea and off the east coast of
North Korea
North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korea, Korean Peninsula and shares borders with China and Russia to the north, at the Yalu River, Y ...
(before 1936), where peak catches were reached from May to June and from April to June, respectively. About 16,000 were caught between 1940 and 1986, when hunting of minke whales ceased.
A small number of minke whales were caught by the
Soviets
Soviet people ( rus, сове́тский наро́д, r=sovyétsky naród), or citizens of the USSR ( rus, гра́ждане СССР, grázhdanye SSSR), was an umbrella demonym for the population of the Soviet Union.
Nationality policy in th ...
in the western North Pacific, with 21 being taken by pelagic fleets between 1933 and 1979 and an additional 94 being caught by catchers operating out of the Kuril Island land stations – the annual catch in the latter region never exceeded nine or ten whales (1951, 1954, and 1956).
One was caught off British Columbia and taken to the whaling station at
Coal Harbour
Coal Harbour is the name for a section of Burrard Inlet lying between Vancouver's Downtown Peninsula and the Brockton Point of Stanley Park. It has also now become the name of the neighbourhood adjacent to its southern shoreline.
Neighbourhoo ...
, on the west coast of
Vancouver Island
Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian Provinces and territories of Canada, province of British Columbia. The island is in length, in width at its widest point, and in total area, while are o ...
, in 1967.Nicol, L. M., E. J. Gregr, R. Flinn, J. K. B. Ford, R. Gurney, L. Michaluk and A. Peacock. (2002). "British Columbia commercial whaling catch data 1908 to 1967: A detailed description of the B.C. historical whaling database". ''Canadian Technical Report of Fisheries and Aquatic Sciences'' No. 2396. viii +76 pp.
Southern Hemisphere
Few dwarf minke whales have been reported taken by whaling operations. Thirteen were caught off
Durban
Durban ( ) ( zu, eThekwini, from meaning 'the port' also called zu, eZibubulungwini for the mountain range that terminates in the area), nicknamed ''Durbs'',Ishani ChettyCity nicknames in SA and across the worldArticle on ''news24.com'' from ...
, South Africa, between 1970 and 1973. Nearly all of them (12 of 13, or 92%) were taken in the first half of the season (April to June), over three-quarters within 30 nautical miles of shore. Of 902 minke whales caught off northeastern Brazil in 1980, only three were dwarf. Of 1,789 minke whales caught in the
Southern Ocean
The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the World Ocean, generally taken to be south of 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-small ...
by the Japanese between 1987–88 and 1992–93, only 16 were dwarf minkes (one was caught in 1987–88, five in 1988–89, three in 1989–90, four in 1990–91, and three in 1992–93).Nishiwaki, S., Ishikawa, H. and Fujise, Y. (2005). "Review of the general methodology and survey procedure under JARPA". ''Paper'' JA/J05/JR2 ''presented at the pre-JARPA review meeting'', ''Tokyo'', January 2005. These were taken from December to March between the latitudes of 55°22'S and 65°04'S and the longitudes of 111°26'E and 178°12'E. An additional 180 minke whales (47 males, 133 females) which had flippers with a "clear white band" were taken by Japanese expeditions in the sub-Antarctic between 1972–73 and 1976–77, with a peak of 69 in 1975–76.
Other mortality
Minke whales are occasionally caught in fishing gear of various types, including set nets, fish pots,
gillnets
Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is ...
, trap nets, trawls, longlines, and seines. Entanglements have been reported off Korea,An, Y. R., Choi, S. G., & Moon, D. Y. (2010). "A review on the status of bycatch minke whales in Korean waters". ''IWC Scientific Committee'' (SC/62/NPM19). ''Available from the IWC''. Japan, Canada,Perkins, J. S., and Beamish, P. C. (1979). "Net entanglements of baleen whales in the inshore fishery of Newfoundland". ''Journal of the Fisheries Board of Canada'' 36 (5): 521-528 (abstract only). the United States, the Azores, Scotland,Northridge, S., Cargill, A., Coram, A., Mandleberg, L., Calderan, S., and Reid, R. (2010). "Entanglement of minke whales in Scottish waters: an investigation into occurrence, causes and mitigation". ''Contract Report''. ''Final Report to Scottish Government'' CR/2007/49. Portugal, France,
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...
,
Greece
Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...
,
Tunisia
)
, image_map = Tunisia location (orthographic projection).svg
, map_caption = Location of Tunisia in northern Africa
, image_map2 =
, capital = Tunis
, largest_city = capital
, ...
,
Israel
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
, the Canary Islands, Senegal, and Brazil. A total of 1,156 minke whales were caught off Korea between 1996 and 2008, an average of about 88 per year. They were mainly caught with set nets (31.4%), fish pots (27.3%), and gillnets (26.2%). Most were juveniles. Of 17 individuals that were reported caught in trap nets off eastern Honshu between 1978 and 1990, only two escaped alive, the rest being sold for their meat. Ship strikes are another source of mortality. They have been reported off the east coast of the United States, in the Gulf of St. Lawrence, and off Italy. A dwarf minke whale calf that stranded in New South Wales had one of its flukes cut by a propeller, which was the likely reason for its stranding and ensuing death.
In April 2007, a juvenile female minke whale died from
domoic acid
Domoic acid (DA) is a kainic acid-type neurotoxin that causes amnesic shellfish poisoning (ASP). It is produced by algae and accumulates in shellfish, sardines, and anchovies. When sea lions, otters, cetaceans, humans, and other predators eat c ...
poisoning by ingesting northern anchovies – a known domoic acid vector – during an intense ''
Pseudo-nitzschia
''Pseudo-nitzschia'' is a marine planktonic diatom genus that accounts for 4.4% of pennate diatoms found worldwide. Some species are capable of producing the neurotoxin domoic acid (DA), which is responsible for the neurological disorder in huma ...
Southern California
Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most po ...
. In March 2013, a severely emaciated juvenile male stranded at
Nieuwpoort, Belgium
Nieuwpoort ( , ; vls, Nieuwpôort; french: Nieuport ) is a city and municipality located in Flanders, one of the three regions of Belgium, and in the Flemish province of West Flanders. The municipality comprises the town of Nieuwpoort proper and ...
. It was believed to have died after a prolonged starvation due to compacted plastic debris obstructing its digestive tract – the first confirmed case of death due to the ingestion of litter in a baleen whale.Jauniaux, T.; Haelters, J.; Degraer, S.; Coignoul, F. (2014). "Fatal plastic impaction in a minke whale (''Balaenoptera acutorostrata'')." In: ''Abstract book of the 28th Annual Conference of the European Cetacean Society: Marine mammals as sentinels of a changing environment'', Liège, Belgium, 5–9 April 2014. pp. 168. In May 2014, a individual that stranded at
Atlantic City, New Jersey
Atlantic City, often known by its initials A.C., is a coastal resort city in Atlantic County, New Jersey, United States. The city is known for its casinos, boardwalk, and beaches. In 2020, the city had a population of 38,497.
, tested positive for
morbillivirus
''Morbillivirus'' is a genus of viruses in the order '' Mononegavirales'', in the family '' Paramyxoviridae''. Humans, dogs, cats, cattle, seals, and cetaceans serve as natural hosts. This genus includes seven species. Diseases in humans associa ...
.
Minke whale strandings on the Atlantic coast of the United States, from Maine to South Carolina, have increased in frequency since January 2017. These strandings have been declared a Unusual Mortality Event (UME) under the
Marine Mammal Protection Act
The Marine Mammal Protection Act (MMPA) was the first act of the United States Congress to call specifically for an ecosystem approach to wildlife management.
Authority
MMPA was signed into law on October 21, 1972, by President Richard Nixon ...
. Full or partial necropsies have been conducted on over 60% of the minke whales stranded on the Atlantic coast since January 2017. Though human interactions and infectious disease were indicated by many of the necropsies, findings have been inconsistent and the cause of the strandings is not fully understood.
Captivity
Several minke whales have been briefly held in captive settings in Japan. All were kept at the Mito Aquarium, in the suburbs of
Numazu, Shizuoka
is a city located in eastern Shizuoka Prefecture, Japan. , the city had an estimated population of 189,486 in 91,986 households, and a population density of 1,014 persons per km2. The total area of the city is .
Geography
Numazu is at the nor ...
, in a square pool netted off from the sea. The first was exhibited for nearly three months in the mid-1930s, but accepted food only during the latter half of its stay. The second was a weeks-old calf that lasted only two weeks in May 1954 before dying. The last was an estimated individual of undetermined sex that had been caught in a fixed net near the aquarium on 26 November 1955 and transported there the same day. It refused the
anchovies
An anchovy is a small, common forage fish of the family Engraulidae. Most species are found in marine waters, but several will enter brackish water, and some in South America are restricted to fresh water.
More than 140 species are placed in 1 ...
given to it – though it may have fed on a school of
mackerel
Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment.
...
s kept in the pool with it – and simply swam in a counter clockwise circle for 37 days before breaking through the nets on the morning of 2 January 1956, not long after three
bottlenose dolphin
Bottlenose dolphins are aquatic mammals in the genus ''Tursiops.'' They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus definitively contains two species: the common ...
s had been introduced to the same pool.
Conservation status
The common minke whale is considered "Least Concern" on the
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
.
In addition, the species is covered by the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region ( Pacific Cetaceans MOU) and the Agreement on the Conservation of Cetaceans in the Black Sea Mediterranean Sea and Contiguous Atlantic Area ( ACCOBAMS).
Gallery
Whale eyeball.jpg, Whale
eyeball
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conve ...
Trachea
The trachea, also known as the windpipe, is a Cartilage, cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends ...
Tongue
The tongue is a muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper surfa ...
lung
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of t ...
kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood ...
artery
An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pul ...
(cut) (''Balaenoptera acutorostrata'').
See also
*
List of cetaceans
Cetacea is an infraorder that comprises the 94 species of whales, dolphins, and porpoises. It is divided into toothed whales (Odontoceti) and baleen whales (Mysticeti), which diverged from each other in the Eocene some 50 million years ago (m ...
*
List of whale vocalizations
Whale vocalizations are the sounds made by whales to communicate. The word "song" is used in particular to describe the pattern of regular and predictable sounds made by some species of whales (notably the humpback) in a way that is reminiscent ...
*
Marine biology
Marine biology is the scientific study of the biology of marine life, organisms in the sea. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies s ...