| Minke whale | |
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| A surfacing minke whale, Skjálfandi, Iceland | |
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| Size comparison against an average human | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Subclass: | Eutheria |
| Order: | Cetacea |
| Suborder: | Mysticeti |
| Family: | Balaenopteridae |
| Genus: | Balaenoptera |
| Species: | B.
acutorostrata B. bonaerensis |
Minke whale (pronounced /ˈmɪŋki/) or lesser rorqual is a name given to two species of marine mammal belonging to a clade[1] within the suborder of baleen whales. The minke whale was given its official designation[2] by Lacepède in 1804,[3] who described a dwarf form of Balænoptera acuto-rostrata.[4]
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Most modern classifications split the minke whale into two species;
Taxonomists further categorize the common minke whale into two or three subspecies; the North Atlantic minke whale, the North Pacific minke whale and dwarf minke whale. All minke whales are part of the rorquals, a family that includes the humpback whale, the fin whale, the Bryde's whale, the sei whale and the blue whale.
The junior synonyms for B. acutorostrata are B. davidsoni (Cope 1872), B. minimia (Rapp, 1837) and B. rostrata (Fabricius, 1780). There is one synonym for B. bonaerensis - B. huttoni (Gray 1874).
Writing in his 1998 classification, Rice recognised two of the subspecies of the common minke whale - B. a. scammoni (Scammon's minke whale) and a further (taxonomically) unnamed subspecies found in the southern hemisphere to which he gave the common name the dwarf minke whale (first described by Best, 1986).
The minke whales are the second smallest baleen whale - only the pygmy right whale is smaller. Upon reaching sexual maturity (6–8 years of age), males measure an average of 6.9 meters (23 ft) and females 7.4 meters (24 ft) in length, respectively. Estimates of maximum length vary from 9.1 to 10.7 metres (30 to 35 ft) for females and 8.8 to 9.8 metres (29 to 32 ft) for males. Both sexes typically weigh 4–5 tonnes (3.9–4.9 LT; 4.4–5.5 ST) at maturity, and the maximum weight may be as much as 14 tonnes (14 LT; 15 ST).
The minke whale is a black/gray color. Common minke whales (northern hemisphere variety) are distinguished from other whales by a white band on each flipper. The body is usually black or dark-gray above and white underneath. Minke whales have between 240 and 360 baleen plates on each side of their mouths. Most of the length of the back, including dorsal fin and blowholes, appears at once when the whale surfaces to breathe.
Minke whales typically live for 30–50 years; in some cases they may live for up to 60 years.
The brains of minke whales have around 12.8 billion neocortical neurons and 98.2 billion neocortical glia.[6]
The whale then breathes 3-5 times at short intervals before 'deep-diving' for 2–20 minutes. Deep dives are preceded by a pronounced arching of the back. The maximum swimming speed of minkes has been estimated at 20 km/h (12 mph).
The gestation period for minke whales is 10 months and babies measure 2.4 to 2.8 metres (7.9 to 9.2 ft) at birth. The newborns nurse for five months. Breeding peaks during the summer months. Calving is thought to occur every two years.[7]
| Multimedia relating to the minke whale Note that whale calls have been sped up to
10x their original speed.
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Minke whales are widely distributed throughout the world, commonly found from the poles to the tropics but prefer the open sea.
In the northeastern Atlantic the total population of minke whales is estimated to be in the order of 103,000 (95% confidence interval, IWC Scientific Committee 2008.)
As of 2008, the estimate for Southern Hemisphere (CPIII with common Northern Boundaries) is 665,074.[8] In the early 1990s the International Whaling Commission (IWC) Scientific Committee agreed that minkes in the Southern Hemisphere numbered 760,000 (CPII), which the Japanese whaling industry currently uses as the (2005) estimate. In 2000, however, the Committee withdrew this advice in light of new survey data suggesting 50% lower population than in the 1980s[9].
Final circumpolar estimates from the IWC IDCR/SOWER population surveys (1978/79-2003/04) were 338,000 — only 39% of the 1985/86-1990/91 surveys.[10] As of January, 2010, The IWC states that it is "unable to to provide reliable estimates at the present time" and that a "major review is underway by the Scientific Committee."[11]
The IUCN Red List labels the northern species as Least Concern and the southern as Data Deficient. CITES on the other hand, list both of the species in Appendix I (threatened) with the exception of the West Greenland stock, which is given in Appendix II (trade controls required). The dwarf minke whale (B. acutorostrata subspecies) has no population estimate, and its conservation status is categorised as "data deficient"..
Whaling was mentioned in Norwegian written sources as early as the year 800 and hunting minke whales with harpoons was common in the 11th century. In the nineteenth century they were considered too small to chase, and received their name from a young Norwegian whale-spotter in the crew of Svend Foyn who harpoooned one mistaking it for a blue whale and was derided for it.[12]
By the end of the 1930s they were the target of coastal whaling by Brazil, Canada, China, Greenland, Japan, Korea, Norway, and South Africa. Minke whales were not then regularly hunted by the large-scale whaling operations in the Southern Ocean because of their relatively small size. However, by the early 1970s, following the over-hunting of larger whales such as the sei, fin, and blue whales, minkes attracted their attention. By 1979 the minke was the only whale caught by Southern Ocean fleets. Hunting continued apace until the general moratorium on whaling began in 1986.
Following the moratorium, most hunting of minke whales ceased. Japan continued catching whales under the special research permit clause in the IWC convention, though in significantly smaller numbers. The stated purpose of the research is to establish data to support a case for the resumption of sustainable commercial whaling. Environmental organizations and several governments contend that research whaling is simply a cover for commercial whaling. The 2006 catch by Japanese whalers included 505 Antarctic minke whales.
Although Norway initially followed the moratorium, they had placed an objection to it with the IWC and resumed a commercial hunt in 1993. The quota for 2006 was set at 1,052 animals, but only 546 was taken.[13] In August 2003, Iceland announced it would start research catches to estimate whether the stocks around the island could sustain hunting. Three years later, in 2006, Iceland resumed commercial whaling.
A 2007 analysis of DNA fingerprinting of whale meat estimated that South Korean fishermen caught 827 minke between 1999 and 2003.[14]
Due to their relative abundance minke whales are often the focus of whale-watching cruises setting sail from, for instance, the Isle of Mull in Scotland, County Cork in Ireland and Húsavík in Iceland. Minke whales are frequently inquisitive and engage in 'human-watching'. In contrast to the spectacularly acrobatic humpback whale, minkes do not raise their flukes out of the water when diving and are less likely to breach (jump clear of the sea surface). This, combined with the fact that minkes can stay submerged for as long as twenty minutes (or possibly their really bad breath) has led some whale-watchers to label them 'stinky minkes'.
In the northern Great Barrier Reef (Australia), a swim-with-whales tourism industry has developed based on the June/July migration of dwarf minke whales. A limited number of reef tourism operators (based in Port Douglas and Cairns) have been granted permits by the Great Barrier Reef Marine Park Authority to conduct these swims, given strict adherence to a Code of Practice, and that operators report details of all sightings as part of a monitoring program. Scientists from James Cook University and the Museum of Tropical Queensland have worked closely with participating operators and the Authority, researching tourism impacts and implementing management protocols to ensure that these interactions are ecologically sustainable.
Minke whales are also occasionally sighted in Pacific waters, in and around the San Juan Islands of Washington State.
In November 2007, a 5.5-metre (18 ft) minke whale ran aground on a sandbar in the Amazon jungle some 1,600 kilometres (990 mi) from the ocean. Scientists said the whale was 5.5-metre (18 ft) long and weighed about 11 tonnes (12 short tons), and were working to return it to the ocean. The whale beached near Santarém in Pará state, Brazil's Environmental Protection Agency said.[15 ] Its corpse was discovered the following week "by local people who reported it to the authorities."[16 ]
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