Minke Whale

Taxobox
name = Minke Whale
status = Text


image_caption = A surfacing Minke Whale, Skjálfandi, Iceland

---

image2_caption = Size comparison against an average human
regnum = Animalia
phylum = Chordata
classis = Mammalia
subclassis = Eutheria
ordo = Cetacea
subordo = Mysticeti
familia = Balaenopteridae
genus = "Balaenoptera"
species = "B. acutorostrata"
"B. bonaerensis"

Minke Whale (pron-en|ˈmɪŋki) or Lesser Rorqual is a name given to two species of marine mammal belonging to a clade [cite web|title=Cetacean mitochondrial DNA control region: sequences of all extant baleen whales and two sperm whale species|url=http://mbe.oxfordjournals.org/cgi/content/abstract/10/5/960|accessdate=2007-07-13] within the suborder of baleen whales. The Minke Whale was given its official designation [It had been inaccurately described by the Danish zoologist Johann Christian Fabricius in 1780, who assumed it must be an already described species, assigned his specimen to "Balaena rostrata", a name, however, that was already in use.] by Lacepède in 1804, [Lacepède, "Histoire naturelle des cétacées." (Paris, 1804).] who described a dwarf form of "Balænoptera acuto-rostrata". [Modern orthography makes it "Balaenoptera acutitostrata".]

Taxonomy

Most modern classifications split the minke whale into two species;
* Common Minke Whale or Northern Minke Whale ("Balaenoptera acutorostrata"), and
*Antarctic Minke Whale or Southern Minke Whale ("Balaenoptera bonaerensis"). [MSW3 Cetacea]

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).

Description

The minke whales are the second smallest of the baleen whales - only the pygmy right whale is smaller. Upon reaching sexual maturity (6-8 years of age), male and female minke whales measure an average of 6.9 and 7.4 metres (22'8" to 24' 3") in length, respectively. Estimates of maximum length vary from 9.1 m to 10.7 m (28'10" to 35'1") for females and 8.8 m to 9.8 m (28'8" 10" to 32'5") for males. Both sexes typically weigh 4-5 tons at maturity, and the maximum weight may be as much as 14 tons. The gestation period for minke whales is 10 months and babies measure 2.4 to 2.8 metres (7'10" to 9'2") at birth. The newborns nurse for five months.

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-grey above and white underneath. Most of the length of the back, including dorsal fin and blowholes, appears at once when the whale surfaces to breathe. 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 20-30 km/h. Minke whales have between 240 and 360 baleen plates on each side of their mouths. Sexual maturity is reached at 7 or 8 years. Breeding peaks during the summer months. The gestation is 10 to 11 months and calving is thought to occur every two years. [http://www.acsonline.org/factpack/MinkeWhale.htm American Cetacean Society: Minke Whale] 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. [Cite journal
author = N. Eriksen, Bente Pakkenberg
title = Total neocortical cell number in the mysticete brain
journal = Anat. Rec.
year = 2007
month = January
volume = 290
issue = 1
pages = 83–95
pmid = 17441201
doi = 10.1002/ar.20404]

Population and distribution

The total population of Minke Whales is estimated to be in the order of 103,000 (95% confidence interval, IWC Scientific Committee 2008 [http://www.iwcoffice.org/_documents/sci_com/SC60docs/sc60docs.htm] ) in North East Atlantic. As of 2008, the estimates for Southern Hemisphere (CPIII with common Northern Boundaries) are 665,074 [http://www.iwcoffice.org/_documents/sci_com/SC60docs/DocList-23-05.pdf] . In the early 1990s the IWC Scientific Committee, after analysing the available data, 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 population estimates 50% lower than in the 1980s (Branch & Butterworth 2001). Final circumpolar estimates from the IWC IDCR/SOWER population surveys (1978/79-2003/04) were 338,000 and were only 39% of those from the 1985/86-1990/91 surveys [cite journal | title = Abundance estimates for Antarctic minke whales from three completed circumpolar sets of surveys, 1978/79 to 2003/04 | author = T.A. Branch | journal = IWC SC paper | volume = SC/58/IA18 | pages = 28 | year = 2006] , however, as of the 2008 Scientific Committee meeting, the figure of 665,074 was presented and discussed at the meeting and, subject to further analysis, will be the accepted 2008 population figure .The IWC has not yet decided whether these estimates reflect a real change in the population or simply a change in the survey methodology. Minke Whales are widely distributed throughout the world, commonly found from the poles to the tropics but prefer the open sea.The IUCN list the northern species as Lower Risk/Near Threatened and the southern as Lower Risk/Conservation dependent. CITES list both of the species in Appendix I (endangered) 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

Whaling was mentioned in Norwegian written sources as early as the year 800 and hunting Minke Whales with harpoons was common in the 11th centuryFact|date=August 2007. 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 (died 1894) who harpoooned one mistaking it for a Blue Whale and was derided for it. [Joseph Horwood, "Biology and exploitation of the minke whale" (CRC Press) 1989:3.]

By the end of the 1930s they were the target of coastal whaling from countries including 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 on account 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 the attention of these whalers too. By 1979 the Minke was the only whale caught by Southern Ocean fleets. Hunting continued apace until the general moratorium on whaling was introduced in 1986.

Following the moratorium, most hunting of Minke Whales ceased. Japan and more recently Iceland (in August 2003) have continued hunting for Minkes on scientific grounds, however, these "scientific grounds" are criticised by many environmental organisations as being a cover for commercial whaling. Both Iceland and Japan have the long term goal of resuming open commercial whaling. Although Norway initially followed the moratorium, they placed an objection to it with the IWC and resumed a commercial hunt in 1993. Norwegian whalers caught 639 in 2005. The quota for 2006 was set at 1052 animals, from which a catch of 546 was taken. [ [http://www.lofotposten.no/lokale_nyheter/article2241060.ece Tok bare halve hvalkvoten - lofotposten.no ] ] The 2006 catch by Japanese whalers included 505 Antarctic Minke Whales. A 2007 analysis of DNA fingerprinting of whale meat estimated that South Korean fishermen caught 827 minke between 1999 and 2003. [cite journal| url=http://environment.newscientist.com/article/mg19426034.100-high-value-of-whale-meat-costs-minkes-in-korea.html| journal=New Scientist| issue=2603| month=10 May| year= 2007| pages= 10| first=Peter| last= Aldhous| title=High value of whale meat costs minkes in Korea| doi=10.1016/S0262-4079(07)61160-9| volume=194] Japan plans to hunt 850 (plus/minus 10%) Antarctic minke whales in 2008.

Minke Whale-watching

(jump clear of the sea surface). This, combined with the fact that Minkes can dive under water for as long as twenty minutes, has led some whale-watching enthusiasts to label them 'stinky Minkes'. The name may also be applied because it is frequently possible to smell the breath of a Minke Whale whilst observing it from a boat.

In the northern Great Barrier Reef (Australia), a swim-with-whales tourism industry has developed based on the seasonal migration of dwarf minke whales during the months of June and July. A limited number of Reef tourism operators (based in Port Douglas and Cairns) have been granted permits by the [http://www.gbrmpa.gov.au/ Great Barrier Reef Marine Park Authority] to conduct these swims, under the conditions that a Code of Practice is strictly adhered to, 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 tourism operators and the Marine Park Authority, researching potential impacts from tourism interactions on the whales and implementing management protocols to ensure that these interactions are ecologically sustainable.

Minke whales are also occasionally sighted in the Pacific waters, in and around the San Juan Islands of Washington State.

2007 Amazon incident

In November 2007, a convert|5.5|m|ft|adj=on Minke Whale ran aground on a sandbar in the Amazon jungle some convert|1600|km|mi from the ocean. Scientists said the whale was convert|5.5|m|ft|adj=on long and weighed about convert|11|t|ST, and were working to dislodge the mammal and return it to the ocean. The whale ran aground on Wednesday near Santarem in Pará state, Brazil's Environmental Protection Agency said, according to BBC News.cite web | last = Duffy | first = Gary | authorlink = | coauthors = | title = Whale found deep in Amazon jungle | work = | publisher = BBC News, Sao Paulo | date = Saturday, 17 November 2007 | url = http://news.bbc.co.uk/2/hi/americas/7099625.stm | format = web | doi = | accessdate = 2007-11-17 ] The whale's corpse was discovered the following Tuesday "by local people who reported it to the authorities."cite web | title = Whale lost in Amazon found dead | publisher = BBC News | date = Wednesday, 21 November 2007 | url = http://news.bbc.co.uk/2/hi/americas/7105578.stm | format = web | accessdate = 2007-01-01]

Conservation status

According to the IUCN Red List, "B. acutorostrata" is considered "Near Threatened", whereas "B. bonaerensis" is "Conservation Dependent".

References

;General references
*ITIS|ID=180524|taxon=Balaenoptera acutorostrata|year=2006|date=18 March
*ITIS|ID=612592|taxon=Balaenoptera bonaerensis|year=2006|date=18 March
*Branch, T. A., and D. S. Butterworth. 2001. "Southern Hemisphere minke whales: standardised abundance estimates from the 1978/79 to 1997/98 IDCR/SOWER surveys". "Journal of Cetacean Research and Management" 3:143-174.
*"Minke Whales", Rus Hoelzel and Jonathon Stern, ISBN 1-900455-75-7
*"National Audubon Society Guide to Marine Mammals of the World", Reeves, Stewart, Clapham and Powell, ISBN 0-375-41141-0
*"Whale Watching in Iceland", Asbjorn Bjorgvinsson and Helmut Lugmayr, ISBN 9979-761-55-5
*"Whales & Dolphins Guide to the Biology and Behaviour of Cetaceans", Maurizio Wurtz and Nadia Repetto. ISBN 1-84037-043-2
*"Encyclopedia of Marine Mammals", editors Perrin, Wursig and Thewissen, ISBN 0-12-551340-2
*"Odin" Norwegian Ministry of Foreign Affairs
* [http://www.thearctic.is/articles/cases/minkewhaling/enska/kafli_0200.htm "Modes of Production and Minke Whaling: The Case of Iceland"] , Gísli Pálsson (2000).

External links

*" [http://www.projectminke.com Project Minke] - Minke whales from the West Coast of Scotland"
*" [http://www.northeastpacificminke.org Northeast Pacific Minke Whale Project] - Minke whales from the Northeast Pacific"
*" [http://www.gbrmpa.gov.au/corp_site/key_issues/conservation/natural_values/whales_dolphins/dwarf_minke_whales Dwarf Minke Whales] - Great Barrier Reef Marine Park Authority - list of permitted swim-with-dwarf minke whales tourism operators on the Great Barrier Reef"
*" [http://www.minkewhaleproject.org Minke Whale Project] - Dwarf minke whale research team based at James Cook University, North Queensland, Australia"
* [http://www.arkive.org/ ARkive] Stills, video.