Blubber#Uses

File:Whale blubber.jpg

Blubber is a thick layer of vascularized adipose tissue under the skin of all cetaceans, pinnipeds, penguins, and sirenians. It was present in many marine reptiles, such as ichthyosaurs and plesiosaurs.{{Cite web |date=2018-12-05 |title=Incredible Jurassic ichthyosaur fossil still has skin and blubber |url=https://www.nationalgeographic.com/science/article/incredible-jurassic-ichthyosaur-fossil-preserves-skin-blubber |access-date=2024-01-12 |website=Science |language=en}}

Description

Lipid-rich, collagen fiber-laced blubber comprises the hypodermis{{cite journal |doi=10.1002/jmor.10154 |title=Blubber development in bottlenose dolphins (Tursiops truncatus) |year=2004 |last1=Struntz |first1=D.J. |last2=McLellan |first2=W.A. |last3=Dillaman |first3=R.M. |last4=Blum |first4=J.E. |last5=Kucklick |first5=J.R. |last6=Pabst |first6=D.A. |journal=Journal of Morphology |volume=259 |pages=7–20 |pmid=14666521 |issue=1|s2cid=24897702 }} and covers the whole body, except for parts of the appendages. It is strongly attached to the musculature and skeleton by highly organized, fan-shaped networks of tendons and ligaments, can comprise up to 50 per cent of the body mass of some marine mammals during some points in their lives, and can range from {{cvt|2|in|cm|order=flip|0}} thick in dolphins and smaller whales, to more than {{cvt|12|in|cm|order=flip}} thick in some bigger whales, such as right and bowhead whales. However, this is not indicative of larger whales' ability to retain heat better, as the thickness of a whale's blubber does not significantly affect heat loss. More indicative of a whale's ability to retain heat is the water and lipid concentration in blubber, as water reduces heat-retaining capacities, and lipid increases them.{{cite journal |doi=10.1016/0306-4565(95)00034-8 |title=Thermal conductivity of minke whale blubber |year=1996 |last1=Kvadsheim |first1=P.H. |last2=Folkow |first2=L.P. |last3=Blix |first3=A.S. |journal=Journal of Thermal Biology |volume=21 |issue=2 |pages=123–8}}

Function

Blubber is the primary fat storage layer for some mammals, especially for those that live in water. It is particularly important for species that feed and breed in different parts of the ocean. During these periods, the animals metabolize fat. Blubber may save energy for marine mammals, such as dolphins, in that it adds buoyancy while swimming.{{cite web |url=http://www.sciencenetlinks.net/sci_update.php?DocID=10 |archive-url=https://web.archive.org/web/20130921054320/http://www.sciencenetlinks.net/sci_update.php?DocID=10 |url-status=dead |archive-date=2013-09-21 |website=Science Update |title=Bouncy Blubber |publisher=AAAS }}

Blubber differs from other forms of adipose tissues due to its extra thickness, which acts as an efficient thermal insulator, making blubber essential for thermoregulation. Blubber is more vascularized—rich in blood vessels—than other adipose tissue.

Blubber has advantages over fur (as in sea otters) in that, though fur retains heat by holding pockets of air, the air expels under pressure (i.e., when the animal dives). Blubber, however, does not compress under pressure. It is effective enough that some whales can dwell in temperatures as low as {{convert|40|F|order=flip}}.{{cite web | url= https://www.pbs.org/oceanrealm/intheschool/school5.html | title= Secrets of the Ocean Realm | url-status= live | archive-url= https://web.archive.org/web/20170504042247/http://www.pbs.org/oceanrealm/intheschool/school5.html | archive-date= 4 May 2017}} While diving in cold water, blood vessels covering the blubber constrict and decrease blood flow, thus increasing blubber's efficiency as an insulator.{{cite book |author= Galbraith, Don|display-authors=et al |title=Biology 11 |location= Canada |publisher= McGraw-Hill Ryerson |page= 12}}

Blubber adds buoyancy and streamlines the body, because the organized, complex collagenous network supports the noncircular cross sections characteristic of cetaceans. The buoyancy of blubber could be problematic for bottom-feeding marine mammals such as sirenians and the extinct marine sloths, both of which do or probably did have limited amounts of it for that reason.{{cite journal|last1= Horgan|first1= P.|last2= Booth|first2= D.|last3= Nichols|first3= C.|last4= Lanyon|first4=J. M.|title= Insulative capacity of the integument of the dugong (Dugong dugon): thermal conductivity, conductance and resistance measured by in vitro heat flux|journal= Marine Biology|volume= 161|issue= 6|year= 2014|pages= 1395–1407|doi= 10.1007/s00227-014-2428-4|s2cid= 83824482}}{{Cite journal|last1= Amson|first1= E.|last2= Argot|first2= C.|last3= McDonald|first3=H. G.|last4=de Muizon|first4= C.|year= 2015|title= Osteology and functional morphology of the axial postcranium of the marine sloth Thalassocnus (Mammalia, Tardigrada) with paleobiological implications|journal= Journal of Mammalian Evolution|volume= 22|issue= 4|pages= 473–518|doi= 10.1007/s10914-014-9280-7|s2cid= 16700349}}

Research{{cite journal |doi= 10.1242/jeb.01559 |title= The ontogenetic changes in the thermal properties of blubber from Atlantic bottlenose dolphin Tursiops truncatus |year=2005 |last1=Dunkin |first1=R. C. |journal=Journal of Experimental Biology |volume=208 |issue=8 |pages=1469–80 |pmid=15802671|doi-access=free }} on the thermal conductivity of the common bottlenose dolphin's blubber reveals that its thickness and lipid content vary greatly amongst individuals and across life history categories. Blubber from emaciated dolphins is a poorer insulator than that from nonpregnant adults, which in turn have a higher heat conductivity than blubber from pregnant females and adolescents.

Human influences

File:Whaling Trypot (Blubber Pot), Simon's Town SA.jpg or Blubber Pot seen in Simon's Town in South Africa]]

=Uses=

Uqhuq,{{cite book|last=Ohokak|first=G.|author2=M. Kadlun|author3=B. Harnum|title=Inuinnaqtun-English Dictionary|publisher=Kitikmeot Heritage Society|url=http://www.nald.ca/library/learning/nac/nac_dictionary/nac_dictionary.pdf|access-date=6 March 2013|url-status=dead|archive-url=https://web.archive.org/web/20120904191006/http://www.nald.ca/library/learning/nac/nac_dictionary/nac_dictionary.pdf|archive-date=4 September 2012}} or uqsuq,{{cite news |url=http://www.livingdictionary.com/term/viewTerm.jsp?term=49165130231 |work=Asuilaak Living Dictionary |title=Blubber |date=November 2016 }}{{dead link|date=July 2017 |bot=InternetArchiveBot |fix-attempted=yes }} ("blubber" in the Inuktitut language) is an important part of the traditional diets of the Inuit and of other northern peoples, because of its high energy value and availability. Whale blubber, which tastes like arrowroot biscuits, has similar properties.

{{cite book

|last1=Stefansson

|first1=Eero

|last2=Adriaensen

|first2=Arxontis

|year=1893

|title=Missionärer bland Eskimåer

|trans-title=Missionaries Among the Eskimos

|language=sv

|publisher=Himmelriket på Jorden Publikationer

|location=Göteborg

|series=Uppdrag i Världen

|page=138

}}

Whaling largely targeted the collection of blubber: whalers rendered it into oil in try pots, or later, in vats on factory ships. The oil could serve in the manufacture of soap, leather, and cosmetics.{{cite encyclopedia | last = Donovan | first = Greg | title = Whaling | encyclopedia = Microsoft Encarta | year = 2008}} Whale oil was used in candles as wax, and in oil lamps as fuel. A single blue whale can yield a blubber harvest of up to 50 tons.{{cite encyclopedia | title = Cetacean | encyclopedia = Encyclopædia Britannica. Ultimate Reference Suite | year = 2008}}

=Health=

Blubber from whales and seals contains omega-3 fatty acids and vitamin D.{{cite journal |last1=Kuhnlein |first1=H.V. |author-link=Harriet V. Kuhnlein |last2=Barthet |first2=V. |last3=Farren |first3=A. |last4=Falahi |first4=E. |last5=Leggee |first5=D. |last6=Receveur |first6=O. |last7=Berti |first7=P. |year=2006 |title=Vitamins A, D, and E in Canadian Arctic traditional food and adult diets |journal=Journal of Food Composition and Analysis |volume=19 |issue=6–7 |pages=495–506 |doi=10.1016/j.jfca.2005.02.007}} Without the vitamin D, for example, the Inuit and other natives of the Arctic would likely suffer from rickets. There is evidence blubber and other fats in the arctic diet also provide the calories needed to replace the lack of carbohydrates which are found in the diets of cultures in the rest of the world.{{cite web|url=http://courses.washington.edu/bioa101/articles/article41.pdf|title=The Inuit Paradox|website=Washington.edu|url-status=live|archive-url=https://web.archive.org/web/20110608052245/http://courses.washington.edu/bioa101/articles/article41.pdf|archive-date=8 June 2011}}

=Toxicity=

In the 21st century, blubber contains man-made polychlorinated biphenyl (PCBs), carcinogens that damage human nervous, immune, and reproductive systems.{{cite journal |doi=10.1126/science.1106882 |title=Two Abundant Bioaccumulated Halogenated Compounds Are Natural Products |year=2005 |last1=Teuten |first1=E. L. |journal=Science |volume=307 |issue=5711 |pages=917–20 |pmid=15705850 |last2=Xu |first2=L |last3=Reddy |first3=CM|bibcode=2005Sci...307..917T |s2cid=9377016 }}

{{cite press release |date=18 February 2005 |title=Chemical Compounds Found In Whale Blubber Are From Natural Sources, Not Industrial Contamination |website=ScienceDaily |url=https://www.sciencedaily.com/releases/2005/02/050213132247.htm}}{{cite web | url=http://news.bbc.co.uk/2/hi/science/nature/1132889.stm | title=Japan warned on 'contaminated' blubber | work=BBC News | date=2001-01-24 | access-date=2009-12-31 | url-status=live | archive-url=https://web.archive.org/web/20090223093530/http://news.bbc.co.uk/2/hi/science/nature/1132889.stm | archive-date=23 February 2009}} The source of PCB concentrations is unknown. Since toothed whales are high on the food chain, they likely consume large amounts of industrial pollutants (bioaccumulation); even baleen whales, by merit of the huge amount of food they consume, are bound to have toxic chemicals stored in their bodies. Additionally, there are high levels of mercury in the blubber of seals of the Canadian arctic.{{cite journal|last1=Braune|first1=B|title=Persistent organic pollutants and mercury in marine biota of the Canadian Arctic: An overview of spatial and temporal trends|journal=Science of the Total Environment|date=16 August 2005|volume=351–352|pages=32|url=http://web4.uwindsor.ca/users/f/fisk/main.nsf/0/48abbaa50ed52cc08525724a006839ac/$FILE/STOTEN%202005%20Braune%20spatial%20temporal%20cont%20Arctic.pdf|bibcode=2005ScTEn.351....4B|doi=10.1016/j.scitotenv.2004.10.034|pmid=16109439|access-date=26 February 2018|archive-date=10 August 2017|archive-url=https://web.archive.org/web/20170810004605/http://web4.uwindsor.ca/users/f/fisk/main.nsf/0/48abbaa50ed52cc08525724a006839ac/%24FILE/STOTEN%202005%20Braune%20spatial%20temporal%20cont%20Arctic.pdf|url-status=dead}}