View source for Biology:Tuna

{{Short description|Tribe of fishes}}
{{pp-semi-indef}}
{{Automatic taxobox
| fossil_range = [[Earth:Ypresian|Ypresian]]-recent , {{Fossil range|56.0|0}}<ref>{{cite web |title=Tribe Thunnini Starks 1910 |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=352611&is_real_user=1 |website=The Paleobiology Database |df=dmy-all |access-date=20 January 2019 |archive-url=https://web.archive.org/web/20190121064857/https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=352611&is_real_user=1 |archive-date=21 January 2019 |url-status=dead}}</ref>
| name = Tuna
| image = tuna_assortment.png
| image_caption = Tunas (from top): [[Biology:Albacore|albacore]], [[Biology:Atlantic bluefin tuna|Atlantic bluefin]], [[Biology:Skipjack tuna|skipjack]], [[Biology:Yellowfin tuna|yellowfin]], [[Biology:Bigeye tuna|bigeye]]
| taxon = Thunnini
| authority = Starks, 1910
| subdivision_ranks = Genera
| subdivision =
* ''[[Biology:Allothunnus|Allothunnus]]:'' slender tunas
* ''[[Biology:Auxis|Auxis]]:'' frigate tunas
* ''[[Biology:Euthynnus|Euthynnus]]:'' little tunas
* ''[[Biology:Katsuwonus|Katsuwonus]]:'' skipjack tunas
* ''[[Biology:Thunnus|Thunnus]]:'' albacores, true tunas
}}

A '''tuna''' ({{plural form}}: '''tunas''' or '''tuna''') is a [[Biology:Saltwater fish|saltwater fish]] that belongs to the [[Biology:Tribe|tribe]] '''Thunnini''', a subgrouping of the [[Biology:Scombridae|Scombridae]] ([[Biology:Mackerel|mackerel]]) family. The Thunnini comprise 15 [[Biology:Species|species]] across five genera,<ref name=Graham2004/> the sizes of which vary greatly, ranging from the [[Biology:Bullet tuna|bullet tuna]] (max length: {{cvt|50|cm|ft|disp=or}}, weight: {{cvt|1.8|kg|lb|0|disp=or}}) up to the [[Biology:Atlantic bluefin tuna|Atlantic bluefin tuna]] (max length: {{cvt|4.6|m|ft|0|disp=or}}, weight: {{cvt|684|kg|lb|0|disp=or}}), which averages {{cvt|2|m|ft}} and is believed to live up to 50 years.

Tuna, [[Biology:Opah|opah]] and mackerel sharks are the only species of [[Biology:Fish|fish]] that can [[Biology:Mesotherm|maintain a body temperature higher than that of the surrounding water]]. An active and agile predator, the tuna has a sleek, streamlined body, and is among the fastest-swimming [[Biology:Pelagic fish|pelagic fish]] – the [[Biology:Yellowfin tuna|yellowfin tuna]], for example, is capable of speeds of up to {{cvt|75|km/h|mph}}.<ref>{{cite journal|last1=Block |first=Barbara A. |last2=Booth |first2=David |last3=Carey |first3=Francis G. |title=Direct measurement of swimming speeds and depth of blue marlin |journal=Journal of Experimental Biology |year=1992 |volume=166 |page=278 |doi=10.1242/jeb.166.1.267 |url=http://jeb.biologists.org/content/166/1/267.full.pdf |archive-url=https://web.archive.org/web/20150904044712/http://jeb.biologists.org/content/166/1/267.full.pdf |archive-date=4 September 2015 |url-status=live |access-date=19 September 2012 |issn=0022-0949}}</ref><ref name=":1">{{Cite journal|last1=Svendsen |first1=Morten B. S.|last2=Domenici |first2=Paolo |last3=Marras |first3=Stefano |last4=Krause |first4=Jens |last5=Boswell |first5=Kevin M. |last6=Rodriguez-Pinto |first6=Ivan |last7=Wilson |first7=Alexander D. M. |last8=Kurvers |first8=Ralf H. J. M. |last9=Viblanc |first9=Paul E. |last10=Finger |first10=Jean S. |last11=Steffensen |first11=John F. |df=dmy-all |title=Maximum swimming speeds of sailfish and three other large marine predatory fish species based on muscle contraction time and stride length: a myth revisited |journal=Biology Open |date=October 2016 |language=en |volume=5 |issue=10 |pages=1415–1419 |doi=10.1242/bio.019919 |pmid=27543056 |pmc=5087677 |issn=2046-6390 |doi-access=free}}</ref> Greatly inflated speeds can be found in early scientific reports and are still widely reported in the popular literature.<ref name=":1" />

Found in warm seas, the tuna is commercially fished extensively as a food fish, and is popular as a bluewater game fish. As a result of overfishing, some tuna species, such as the [[Biology:Southern bluefin tuna|southern bluefin tuna]], are threatened with [[Biology:Extinction|extinction]].<ref name=IUCNmaccoyii />


==Etymology==
The term "tuna" comes from [[Social:Spanish language|Spanish]] ''atún'' < Andalusian Arabic ''at-tūn'', assimilated from ''al-tūn'' {{lang|ar|التون}} [Modern Arabic {{lang|ar|التن}}] : 'tuna fish' < Middle Latin ''thunnus''.<ref>{{cite dictionary|url=https://www.ahdictionary.com/word/search.html?q=tuna&submit.x=0&submit.y=0|title=tuna |dictionary=American Heritage Dictionary |publisher=Houghton Mifflin Harcourt Publishing Company |date=2015 |df=dmy-all |access-date=24 May 2015 |archive-url=https://web.archive.org/web/20150524153815/https://www.ahdictionary.com/word/search.html?q=tuna&submit.x=0&submit.y=0 |archive-date=24 May 2015 |url-status=dead}}</ref> ''{{lang|la|Thunnus}}'' is derived from {{lang-grc|θύννος|thýnnos}} used for the [[Biology:Atlantic bluefin tuna|Atlantic bluefin tuna]],<ref>{{cite dictionary |url=https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0059:entry=thunnus |title= thunnus |last1= Lewis |first1= Charlton T. |last2= Short |first2= Charles |dictionary= A Latin Dictionary |edition= |publisher= Perseus Digital Library |date = 1879 }}</ref> that name in turn is ultimately derived from {{lang|grc|θύνω}} ''thýnō'', meaning "to rush, dart along".<ref>{{LSJ|qu/nnos|θύννος|longref}}</ref><ref>{{LSJ|qu/nw|θύνω|shortref}}.</ref>

==Taxonomy==
The Thunnini tribe is a [[Biology:Monophyletic|monophyletic]] [[Biology:Clade|clade]] comprising 15 species in five genera:
:* family [[Biology:Scombridae|Scombridae]]
:** '''tribe Thunnini: tunas'''
:*** genus ''[[Biology:Allothunnus|Allothunnus]]:'' slender tunas
:*** genus ''[[Biology:Auxis|Auxis]]:'' frigate tunas
:*** genus ''[[Biology:Euthynnus|Euthynnus]]:'' little tunas
:*** genus ''[[Biology:Katsuwonus|Katsuwonus]]:'' skipjack tunas
:*** genus ''[[Biology:Thunnus|Thunnus]]:'' albacores and true tunas
:**** [[Biology:Subgenus|subgenus]] ''Thunnus ([[Biology:Thunnus (subgenus)|Thunnus]])'': bluefin group
:**** subgenus ''Thunnus (Neothunnus)'': yellowfin group

The [[Biology:Cladogram|cladogram]] is a tool for visualizing and comparing the evolutionary relationships between taxa, and is read left-to-right as if on a timeline. The following cladogram illustrates the relationship between the tunas and other tribes of the family Scombridae. For example, the cladogram illustrates that the [[Biology:Skipjack tuna|skipjack tuna]]s are more closely related to the true tunas than are the [[Biology:Slender tuna|slender tuna]]s (the most primitive of the tunas), and that the next nearest relatives of the tunas are the [[Biology:Bonito|bonito]]s of the tribe Sardini.<ref name=Graham2004/>

<div class="thumb" style="margin: 5px; clear: left; width: 98%;">
<div class="overflowbugx" style="overflow:auto;border=1">
{{cladogram|title=The Tunas: Thunnini tribe, within the Family Scombridae
|align=left |caption=Cladogram: Tunas are classified into the tribe Thunnini (bottom-center in the above diagram)&nbsp;– one of four tribes in the family Scombridae.<ref name=Graham2004>{{cite journal|last1=Graham |first1=Jeffrey B. |last2=Dickson |first2=Kathryn A. |title=Tuna Comparative Physiology |journal=The Journal of Experimental Biology |year=2004 |volume=207 |issue=23 |pages=4015–4024 |doi=10.1242/jeb.01267 |pmid=15498947 |doi-access=free}}</ref>
|cladogram={{clade| style=font-size:80%;line-height:80%;width:820px;
    |label1=family&nbsp;[[Biology:Scombridae|Scombridae]]&nbsp;
    |1={{clade
        |label1=&nbsp;subfamily
        |1={{clade
            |label1=Gasterochismatinae&nbsp;
            |1={{clade
                |1={{clade
                    |1=&nbsp;[[Biology:Butterfly kingfish|Butterfly kingfish]]es&nbsp;(one genus)
                    }}
                }}
            }}
        |label2=&nbsp;subfamily
        |2={{clade
            |label1=[[Biology:Scombrinae|Scombrinae]]&nbsp;
            |1={{clade
                |1={{clade
                    |label1=tribe&nbsp;[[Biology:Scombrini|Scombrini]]&nbsp;
                    |1={{clade
                        |1=&nbsp;[[Biology:Mackerel|Mackerel]]s&nbsp;(two genera) <span style="{{MirrorH}}">[[File:Scomber scombrus.png|50 px]]</span>
                        }}
                    }}
                |2={{clade
                    |1={{clade
                        |label1=tribe&nbsp;Scomberomorini&nbsp;
                        |1=&nbsp;[[Biology:Spanish mackerel|Spanish mackerel]]s&nbsp;(three genera) <span style="{{MirrorH}}">[[File:Scomberomorus cavalla.png|50 px]]</span>
                        }}
                    |2={{clade
                        |1={{clade
                            |label1=tribe&nbsp;[[Biology:Sardini|Sardini]]&nbsp;
                            |1={{clade
                                |1={{clade
                                    |1=&nbsp;[[Biology:Bonito|Bonito]]s&nbsp;(four genera) <span style="{{MirrorH}}">[[File:Sarda sarda.jpg|50 px]]</span>
                                    }}
                                }}
                            }}
                        |2={{clade
                            |label1={{green|&nbsp;tribe&nbsp;'''Thunnini,'''}}
                            |1={{clade
                                |label1={{green|&nbsp;'''Tunas'''&nbsp;}}
                                |1={{clade |thickness=2
                                    |1=&nbsp;{{green|''[[Biology:Allothunnus|Allothunnus]]'',&nbsp;slender tunas}}
                                    |2={{clade |thickness=2
                                        |1=&nbsp;{{green|''[[Biology:Auxis|Auxis]]'',&nbsp;frigate tunas}} [[File:XRF-Auxis thazard.png|50 px]]
                                        |2={{clade |thickness=2
                                            |1=&nbsp;{{green|''[[Biology:Euthynnus|Euthynnus]]'',&nbsp;little tunas}} [[File:XRF-Euthynnus alletteratus.png|50 px]]
                                            |2={{clade |thickness=2
                                                |1=&nbsp;{{green|''[[Biology:Katsuwonus|Katsuwonus]]'',&nbsp;skipjack tunas}} <span style="{{MirrorH}}">[[File:Katsuwonus pelamis.png|50 px]]</span>
                                                |2={{clade |thickness=2
                                                    |label1=&nbsp;{{green|''[[Biology:Thunnus|Thunnus]]'',&nbsp;true tunas}}&nbsp;
                                                    |1={{clade |thickness=2
                                                        |label1=&nbsp;{{green|subgenus ''[[Biology:Thunnus (subgenus)|Thunnus]]''}}
                                                        |1=&nbsp;{{black|bluefin group}} <span style="{{MirrorH}}">[[File:Thunnus thynnus.png|50 px]]</span>
                                                        |label2=&nbsp;{{green|subgenus ''Neothunnus''}}
                                                        |2=&nbsp;{{black|yellowfin group}} <span style="{{MirrorH}}">[[File:Thunnus albacares.png|50 px]]</span>
                                                        }}
                                                    }}
                                                }}
                                            }}
                                        }}
                                    }}
                                }}
                            }}
                        }}
                    }}
                }}
            }}
        }}
    }}
}}
</div></div>

{{Clear}}

===True species===
[[File:Tuna Relative Sizes.jpg|thumb|Relative sizes of various tunas, with the Atlantic bluefin tuna (top) at about {{convert|8|ft|m|abbr=on}} in this sample]]
The "true" tunas are those that belong to the genus ''Thunnus''. Until recently, it was thought that there were seven ''Thunnus'' species, and that [[Biology:Atlantic bluefin tuna|Atlantic bluefin tuna]] and [[Biology:Pacific bluefin tuna|Pacific bluefin tuna]] were [[Biology:Subspecies|subspecies]] of a single species. In 1999, Collette established that based on both molecular and morphological considerations, they are in fact distinct species.<ref>{{cite conference|last=Collette |first=B.B. |conference=5th Indo-Pacific Fish Conference: Nouméa, New Caledonia, 3–8 November 1997 |editor=Séret, B. |editor2=Sire, J.Y. |title=Mackerels, molecules, and morphology|year=1999|publisher=Société Française d'Ichtyologie [u.a.] |book-title=Proceedings |location=Paris|isbn=978-2-9507330-5-4 |pages=149–164 |url=https://books.google.com/books?id=-0cWAQAAIAAJ}}</ref><ref name=Tanaka2006>{{cite journal |last1=Tanaka |first1=Y. |first2=K. |last2=Satoh |first3=M. |last3=Iwahashi |first4=H. |last4=Yamada |title=Growth-dependent recruitment of Pacific bluefin tuna ''Thunnus orientalis'' in the northwestern Pacific Ocean |journal=Marine Ecology Progress Series |year=2006 |volume=319 |pages=225–235 |url=http://cat.inist.fr/?aModele=afficheN&cpsidt=18108521 |doi=10.3354/meps319225|bibcode=2006MEPS..319..225T |doi-access=free}}</ref>

The genus ''Thunnus'' is further classified into two subgenera: ''Thunnus ([[Biology:Thunnus (subgenus)|Thunnus]])'' (the bluefin group), and ''Thunnus (Neothunnus)'' (the yellowfin group).<ref>{{Cite web|title=Thunnus - an overview {{!}} ScienceDirect Topics|url=https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/thunnus|access-date=2021-08-17|website=www.sciencedirect.com}}</ref>
{{Clear}}
:{{Tuna table/Header|''[[Biology:Thunnus|Thunnus]]'', the true tunas}}
{{Tuna table/Thunnus (Thunnus)}}
{{Tuna table/Thunnus (Neothunnus)}}
|}

===Other species===
The Thunnini tribe also includes seven additional species of tuna across four genera. They are:

:{| class="wikitable"
|-
! colspan="9"| Other tuna species
|-
! style="width:10em" | Common name
! style="width:11em" | Scientific name
! Maximum<br/>length
! Common<br/>length
! Maximum<br/>weight
! Maximum<br/>age
! [[Earth:Trophic level|Trophic<br/>level]]
! Source
! style="width:11em" |IUCN status
|-
| [[Biology:Slender tuna|Slender tuna]]
| ''[[Biology:Allothunnus|Allothunnus]] fallai''<br/><small>(Serventy, 1948) </small>
| style="text-align:right;"| {{convert|1.05|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|0.86|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|13.7|kg|lb|abbr=on|disp=br()}}
| style="text-align:right;"|
| style="text-align:center;"| 3.74
| style="text-align:center;"|<ref name=FBfallai>{{FishBase | genus = Allothunnus | species = fallai | month = January | year = 2012}}</ref>
| [[File:LC IUCN 3 1.svg|LC IUCN 3 1.svg]] <small>Least concern</small><ref name=IUCNfallai>{{cite iucn |author=Collette, B. |author2=Amorim, A.F. |author3=Boustany, A. |author4=Carpenter, K.E. |author5=de Oliveira Leite Jr. |author6=N. |author7=Di Natale, A. |author8=Fox, W. |author9=Fredou, F.L. |author10=Graves, J. |author11=Viera Hazin, F.H. |author12=Juan Jorda, M. |author13=Minte Vera, C. |author14=Miyabe, N. |author15=Nelson, R. |author16=Oxenford, H. |author17=Sun, C. |author18=Teixeira Lessa, R.P. |author19=Pires Ferreira Travassos, P.E. |author20=Uozumi, Y. |date=2011 |title=''Allothunnus fallai'' |volume=2011 |page=e.T170349A6761139 |doi=10.2305/IUCN.UK.2011-2.RLTS.T170349A6761139.en |access-date=12 November 2021}}</ref>
|-
| [[Biology:Bullet tuna|Bullet tuna]]
| ''[[Biology:Auxis|Auxis]] rochei''<br/><small>(Risso, 1810)</small>
| style="text-align:right;"| {{convert|0.5|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|0.35|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|1.8|kg|lb|abbr=on|disp=br()}}
| style="text-align:right;"| 5 years
| style="text-align:center;"| 4.13
| style="text-align:center;"|<ref name=FBrochei>{{FishBase | genus = Auxis | species = rochei | month = January | year = 2012}}</ref><ref name=IUCNrochei/>
| [[File:LC IUCN 3 1.svg|LC IUCN 3 1.svg]] <small>Least concern</small><ref name=IUCNrochei>{{cite iucn |author=Collette, B. |author2=Acero, A. |author3=Amorim, A.F. |author4=Boustany, A. |author5=Canales Ramirez, C. |author6=Cardenas, G. |author7=Carpenter, K.E. |author8=de Oliveira Leite Jr. |author9=N. |author10=Di Natale, A. |author11=Fox, W. |author12=Fredou, F.L. |author13=Graves, J. |author14=Guzman-Mora, A. |author15=Viera Hazin, F.H. |author16=Juan Jorda, M. |author17=Kada, O. |author18=Minte Vera, C. |author19=Miyabe, N. |author20=Montano Cruz, R. |author21=Nelson, R. |author22=Oxenford, H. |author23=Salas, E. |author24=Schaefer, K. |author25=Serra, R. |author26=Sun, C. |author27=Teixeira Lessa, R.P. |author28=Pires Ferreira Travassos, P.E. |author29=Uozumi, Y. |author30=Yanez, E. |date=2011 |title=''Auxis rochei'' |volume=2011 |page=e.T170355A6765188 |doi=10.2305/IUCN.UK.2011-2.RLTS.T170355A6765188.en |access-date=12 November 2021}}</ref>
|-
| [[Biology:Frigate tuna|Frigate tuna]]
| ''Auxis thazard''&nbsp;<br/><small>(Lacépède, 1800)</small>
| style="text-align:right;"| {{convert|0.65|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|0.35|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|1.7|kg|lb|abbr=on|disp=br()}}
| style="text-align:right;"| 5 years
| style="text-align:center;"| 4.34
| style="text-align:center;"|<ref name=FBthazard>{{FishBase | genus = Auxis | species = thazard | month = January | year = 2012}}</ref>
| [[File:LC IUCN 3 1.svg|LC IUCN 3 1.svg]] <small>Least concern</small><ref name=IUCNthazard>{{cite iucn |author=Collette, B. |author2=Acero, A. |author3=Amorim, A.F. |author4=Boustany, A. |author5=Canales Ramirez, C. |author6=Cardenas, G. |author7=Carpenter, K.E. |author8=de Oliveira Leite Jr. |author9=N. |author10=Di Natale, A. |author11=Fox, W. |author12=Fredou, F.L. |author13=Graves, J. |author14=Guzman-Mora, A. |author15=Viera Hazin, F.H. |author16=Juan Jorda, M. |author17=Kada, O. |author18=Minte Vera, C. |author19=Miyabe, N. |author20=Montano Cruz, R. |author21=Nelson, R. |author22=Oxenford, H. |author23=Salas, E. |author24=Schaefer, K. |author25=Serra, R. |author26=Sun, C. |author27=Teixeira Lessa, R.P. |author28=Pires Ferreira Travassos, P.E. |author29=Uozumi, Y. |author30=Yanez, E. |date=2011 |title=''Auxis thazard'' |volume=2011 |page=e.T170344A6757270 |doi=10.2305/IUCN.UK.2011-2.RLTS.T170344A6757270.en |access-date=12 November 2021}}</ref>
|-
| [[Biology:Euthynnus affinis|Mackerel tuna]],<br />[[Biology:Euthynnus affinis|Kawakawa]]
| ''[[Biology:Euthynnus|Euthynnus]] affinis''<br/><small>(Cantor, 1849)</small>
| style="text-align:right;"| {{convert|1.0|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|0.6|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|13.6|kg|lb|abbr=on|disp=br()}}
| style="text-align:right;"| 6 years
| style="text-align:center;"| 4.50
| style="text-align:center;"|<ref name=FBaffinis>{{FishBase | genus = Euthynnus | species = affinis | month = January | year = 2012}}</ref><ref name=IUCNaffinis/>
| [[File:LC IUCN 3 1.svg|LC IUCN 3 1.svg]] <small>Least concern</small><ref name=IUCNaffinis>{{cite iucn |author=Collette, B. |author2=Chang, S.-K. |author3=Fox, W. |author4=Juan Jorda, M. |author5=Miyabe, N. |author6=Nelson, R. |author7=Uozumi, Y. |date=2011 |title=''Euthynnus affinis'' |volume=2011 |page=e.T170336A6753804 |doi=10.2305/IUCN.UK.2011-2.RLTS.T170336A6753804.en |access-date=12 November 2021}}</ref>
|-
| [[Biology:Little tunny|Little tunny]]
| ''Euthynnus alletteratus''<br/><small>(Rafinesque, 1810)</small>
| style="text-align:right;"| {{convert|1.2|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|0.8|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|16.5|kg|lb|abbr=on|disp=br()}}
| style="text-align:right;"| 10 years
| style="text-align:center;"| 4.13
| style="text-align:center;"|<ref name=FBalletteratus>{{FishBase | genus = Euthynnus | species = alletteratus | month = January | year = 2012}}</ref>
| [[File:LC IUCN 3 1.svg|LC IUCN 3 1.svg]] <small>Least concern</small><ref name=IUCNalletteratus>{{cite iucn |author=Collette, B. |author2=Amorim, A.F. |author3=Boustany, A. |author4=Carpenter, K.E. |author5=de Oliveira Leite Jr. |author6=N. |author7=Di Natale, A. |author8=Fox, W. |author9=Fredou, F.L. |author10=Graves, J. |author11=Viera Hazin, F.H. |author12=Juan Jorda, M. |author13=Kada, O. |author14=Minte Vera, C. |author15=Miyabe, N. |author16=Nelson, R. |author17=Oxenford, H. |author18=Teixeira Lessa, R.P. |author19=Pires Ferreira Travassos, P.E. |date=2011 |title=''Euthynnus alletteratus'' |volume=2011 |page=e.T170345A6759394 |doi=10.2305/IUCN.UK.2011-2.RLTS.T170345A6759394.en |access-date=12 November 2021}}</ref>
|-
| Black skipjack tuna&nbsp;
| ''Euthynnus lineatus''<br/><small>(Kishinouye, 1920)</small>
| style="text-align:right;"| {{convert|0.84|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|0.6|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|11.8|kg|lb|abbr=on|disp=br()}}
| style="text-align:right;"|
| style="text-align:center;"| 3.83
| style="text-align:center;"|<ref name=FBlineatus>{{FishBase | genus = Euthynnus | species = lineatus | month = January | year = 2012}}</ref><ref name=IUCNlineatus/>
| [[File:LC IUCN 3 1.svg|LC IUCN 3 1.svg]] <small>Least concern</small><ref name=IUCNlineatus>{{cite iucn |author=Collette, B. |author2=Acero, A. |author3=Canales Ramirez, C. |author4=Cardenas, G. |author5=Carpenter, K.E. |author6=Di Natale, A. |author7=Guzman-Mora, A. |author8=Montano Cruz, R. |author9=Nelson, R. |author10=Schaefer, K. |author11=Serra, R. |author12=Yanez, E. |date=2011 |title=''Euthynnus lineatus'' |volume=2011 |page=e.T170320A6747016 |doi=10.2305/IUCN.UK.2011-2.RLTS.T170320A6747016.en |access-date=12 November 2021}}</ref>
|-
| [[Biology:Skipjack tuna|Skipjack tuna]]
| ''[[Biology:Katsuwonus|Katsuwonus]] pelamis''<br/><small>([[Biography:Carl Linnaeus|Linnaeus]], 1758)</small>
| style="text-align:right;"| {{convert|1.1|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|0.8|m|ft|abbr=on|disp=br()}}
| style="text-align:right;"| {{convert|34.5|kg|lb|abbr=on|disp=br()}}
| style="text-align:right;"| 6–12 yrs
| style="text-align:center;"| 3.75
| style="text-align:center;"|<ref name=FBpelamis>{{FishBase | genus = Katsuwonus | species = pelamis | month = January | year = 2012}}</ref><ref name=IUCNpelamis/>
| [[File:LC IUCN 3 1.svg|LC IUCN 3 1.svg]] <small>Least concern</small><ref name=IUCNpelamis>{{cite iucn |author=Collette, B.B. |author2=Boustany, A. |author3=Fox, W. |author4=Graves, J. |author5=Juan Jorda, M. |author6=Restrepo, V. |date=2021 |title=''Katsuwonus pelamis'' |volume=2021 |page=e.T170310A46644566 |doi=10.2305/IUCN.UK.2021-2.RLTS.T170310A46644566.en |access-date=12 November 2021}}</ref>
|}

==Biology==
[[File:Thunnus obesus (Bigeye tuna) diagram cropped.GIF|thumb|[[Biology:Bigeye tuna|Bigeye tuna]] ''Thunnus obesus'' showing finlets and keels. Finlets are found between the last dorsal and/or anal fin and the caudal fin. They are rayless and non-retractable.<br/>Drawing by Dr Tony Ayling.]]

=== Description ===
The tuna is a sleek, elongated and streamlined fish, adapted for speed. It has two closely spaced but separated dorsal fins on its back; The first fin is "depressible"&nbsp;– it can be laid down, flush, in a groove that runs along its back; it is supported by spines.<ref name="FAO">{{cite book |author=<!--Staff writer(s); no by-line.--> |date=n.d. |title=Biological characteristics of tuna  |url=https://www.fao.org/figis/pdf/fishery/topic/16082/en?title=FAO%20Fisheries%20%26%20Aquaculture%20-%20Biological%20characteristics%20of%20tuna|publisher=Fisheries and Aquaculture Department, Food and Agriculture Organization |access-date=17 December 2022 }}</ref> Seven to ten yellow finlets run from the dorsal fins to the tail, which is lunate&nbsp;– curved like a crescent moon&nbsp;– and tapered to pointy tips.<ref name=RISeaGrant>{{cite web|last=Gibbs |first=E. |title=Fact Sheet: Tuna #P1412 |url=http://seagrant.gso.uri.edu/factsheets/tuna.html |publisher=Rhode Island Sea Grant |access-date=20 September 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120712070954/http://seagrant.gso.uri.edu/factsheets/tuna.html |archive-date=12 July 2012}}</ref> A tuna's pelvic fins are located below the base of the pectoral fins. Both dorsal and pelvic fins retract when the fish is swimming fast.<ref name="FAO"/>

The tuna's body is countershaded to [[Biology:Camouflage|camouflage]] itself in deeper water when seen from above, its dorsal side is generally a metallic dark blue while the ventral or under side is silvery, often with an [[Physics:Iridescence|iridescent]] shine.<ref>{{cite web |last1=Argo |first1=Emily |title=Countershading |date=21 April 2017 |url=https://fishionary.fisheries.org/countershading/ |website=Fishionary |publisher=[[Organization:American Fisheries Society|American Fisheries Society]] |access-date=17 December 2022}}</ref><ref name=RISeaGrant/> The caudal peduncle, to which the tail is attached, is quite thin, with three stabilizing horizontal keels on each side.<ref name=RISeaGrant/>

===Physiology===
''Thunnus'' are widely but sparsely distributed throughout the oceans of the world, generally in tropical and temperate waters at [[Earth:Latitude|latitude]]s ranging between about 45° north and south of the equator.<ref name="ISSF"/> All tunas are able to maintain the temperature of certain parts of their body above the temperature of ambient seawater. For example, bluefin can maintain a core body temperature of {{Convert|25|-|33|C|F}}, in water as cold as {{Convert|6|C|F}}. Unlike other endothermic creatures such as mammals and birds, tuna do not maintain temperature within a relatively narrow range.<ref name=muscletemp>{{cite journal|last1=Sepulveda |first1=C.A. |last2=Dickson |first2=K.A. |last3=Bernal |first3=D. |last4=Graham |first4=J.B. |title=Elevated red myotomal muscle temperatures in the most basal tuna species, ''Allothunnus fallai'' |journal=Journal of Fish Biology |date=1 July 2008 |volume=73 |issue=1 |pages=241–249 |doi=10.1111/j.1095-8649.2008.01931.x |url=http://216.172.180.32/~pier/userdocs/images/files/scientific_publications/Sepulveda%20et%20al.%202008%20.pdf |access-date=2 November 2012 |url-status=dead |archive-url=https://web.archive.org/web/20130207000108/http://216.172.180.32/~pier/userdocs/images/files/scientific_publications/Sepulveda%20et%20al.%202008%20.pdf |archive-date=7 February 2013}}</ref>

Tunas achieve endothermy by conserving the heat generated through normal [[Biology:Metabolism|metabolism]]. In all tunas, the heart operates at [[Physics:Ambient temperature|ambient temperature]], as it receives cooled blood, and coronary circulation is directly from the gills.<ref name=SERCA2/> The ''[[Biology:Rete mirabile|rete mirabile]]'' ("wonderful net"), the intertwining of veins and arteries in the body's periphery, allows nearly all of the metabolic heat from venous blood<!-- NOT arterial --> to be "re-claimed" and transferred to the [[Medicine:Arterial blood|arterial blood]]<!-- NOT venous --> via a counter-current exchange system, thus mitigating the effects of surface cooling.<ref name=Cech1984>{{cite journal |last1=Cech |first1=J.J. |last2=Laurs |first2=R.M. |last3=Graham |first3=J.B. |year=1984 |title=Temperature-induced changes in blood gas equilibria in the albacore, ''Thunnus alalunga'', a warm-bodied tuna |journal=Journal of Experimental Biology |volume=109 |issue=1 |pages=21–34 |doi=10.1242/jeb.109.1.21 |url=http://jeb.biologists.org/content/109/1/21.full.pdf |archive-url=https://web.archive.org/web/20150904044712/http://jeb.biologists.org/content/109/1/21.full.pdf |archive-date=2015-09-04 |url-status=live|quote=Oxygenated blood that has just reached thermal equilibrium with ambient sea water in the gills enters the rete on the arterial side, while warmed, deoxygenated, and carbon dioxide-laden blood enters on the venous end. In the rete, countercurrent flow and the high surface area contact between the two blood supplies facilitate the transfer of nearly all of the metabolic heat in the venous blood to arterial blood, thus conserving muscle temperature. After exiting the rete, arterial blood continues to the red muscle capillary beds, and cooled venous blood flows to the gills where carbon dioxide is excreted and oxygen is loaded.|doi-access=free }}</ref> This allows the tuna to elevate the temperatures of the highly-aerobic tissues of the skeletal muscles, eyes and brain,<ref name=muscletemp/><ref name=SERCA2>{{cite journal|last1=Landeira-Fernandez |first1=A.M. |last2=Morrissette |first2=J.M. |last3=Blank |first3=J.M. |last4=Block |first4=B.A. |title=Temperature dependence of the Ca<sup>2+</sup>-ATPase (SERCA2) in the ventricles of tuna and mackerel|journal=American Journal of Physiology. Regulatory, Integrative and Comparative Physiology|date=16 October 2003|volume=286|issue=2|pages=R398–R404|doi=10.1152/ajpregu.00392.2003|pmid=14604842}}</ref> which supports faster swimming speeds and reduced energy expenditure, and which enables them to survive in cooler waters over a wider range of ocean environments than those of other fish.{{citation needed|date=August 2022}}

Also unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red [[Biology:Myotome|myotomal]] muscles derive their color from [[Biology:Myoglobin|myoglobin]], an oxygen-binding molecule, which tuna express in quantities far higher than most other fish. The oxygen-rich blood further enables energy delivery to their muscles.<ref name=muscletemp/>

For powerful swimming animals like [[Biology:Dolphin|dolphin]]s and tuna, [[Physics:Cavitation|cavitation]] may be detrimental, because it limits their maximum swimming speed.<ref name=speedlimit>{{cite journal|last1=Iosilevskii|first1=G|last2=Weihs|first2=D|title=Speed limits on swimming of fishes and cetaceans|journal=Journal of the Royal Society Interface|date=6 March 2008|volume=5|issue=20|pages=329–338|doi=10.1098/rsif.2007.1073|pmid=17580289|quote=Lacking pain receptors on their caudal fins, scombrids may temporarily cross the cavitation limit, and cavitation-induced damage has been observed (Kishinouye 1923); on the other hand, delphinids probably cannot cross it without pain (Lang 1966)|pmc=2607394}}</ref> Even if they have the power to swim faster, dolphins may have to restrict their speed, because collapsing cavitation bubbles on their tail are too painful. Cavitation also slows tuna, but for a different reason. Unlike dolphins, these fish do not feel the bubbles, because they have bony fins without nerve endings. Nevertheless, they cannot swim faster because the cavitation bubbles create a vapor film around their fins that limits their speed. Lesions have been found on tuna that are consistent with cavitation damage.<ref name=speedlimit/>

==Fishing==
[[File:Tuna all sizes Pengo.svg|thumb|350px|Maximum reported sizes of tuna species|alt=Bar chart that states ''Thunnus thynnus'' is the largest tuna, at {{Convert|458|cm|in}} followed by ''Thunnus orientalis'' at {{Convert|300|cm|in}}, ''Thunnus obsesus'' at {{Convert|250|cm|in}}, ''Gymnosarda unicolor'' at {{Convert|248|cm|in}}, ''Thunnus maccoyii'' at {{Convert|245|cm|in}}, ''Thunnus albacares'' at {{Convert|239|cm|in}}, ''Gasterochisma melampus'' at {{Convert|164|cm|in}}, ''Thunnus tonggol'' at {{Convert|145|cm|in}}, ''Thunnus alalunga'' at {{Convert|140|cm|in}}, ''Euthynnus alletteratus'' at {{Convert|122|cm|in}}, ''Katsuwonus pelamis'' at {{Convert|108|cm|in}}, ''Thunnus atlanticus'' at {{Convert|108|cm|in}}, ''Allothunnus fallai'' at {{Convert|105|cm|in}}, ''Euthynnus affinis'' at {{Convert|100|cm|in}}, ''Auxis thazard thazard'' at {{Convert|65|cm|in}},''Auxis rochei rochei'' at {{Convert|50|cm|in}}, and ''Auxis rochei eudorax'' at {{Convert|36.5|cm|in}}]]

===Commerce===
Tuna is an important commercial fish. The International Seafood Sustainability Foundation (ISSF) compiled a detailed scientific report on the state of global tuna stocks in 2009, which includes regular updates. According to the ISSF, the most important species for commercial and recreational tuna fisheries are yellowfin (''Thunnus albacares''), bigeye (''T. obesus''), bluefin (''T. thynnus'', ''T. orientalis'', and ''T. macoyii''), albacore (''T. alalunga''), and skipjack (''Katsuwonus pelamis'').<ref name="ISSF">{{cite web |url=http://www.iss-foundation.org/files/b45a4eb2-f9d7-4ed6-87a1-2efe2519baf6/ISSF_A-1%20Introduction.pdf
|title=Status of the World Fisheries for Tuna: Section A-1 – Introduction |publisher=International Seafood Sustainability Foundation |date= 15 April 2009 |df=dmy-all |access-date=10 November 2009 |archive-url=https://web.archive.org/web/20100327021649/http://www.iss-foundation.org/files/b45a4eb2-f9d7-4ed6-87a1-2efe2519baf6/ISSF_A-1%20Introduction.pdf |archive-date=27 March 2010 }}</ref>

Based on catches from 2007, the report states:

{{Blockquote|Between 1940 and the mid-1960s, the annual world catch of the five principal market species of tunas rose from about 300 thousand tons to about 1 million tons, most of it taken by hook and line. With the development of [[Engineering:Seine fishing|purse-seine]] nets, now the predominant gear, catches have risen to more than 4 million tons annually during the last few years. Of these catches, about 68 percent are from the [[Earth:Pacific Ocean|Pacific Ocean]], 22 percent from the [[Earth:Indian Ocean|Indian Ocean]], and the remaining 10 percent from the [[Earth:Atlantic Ocean|Atlantic Ocean]] and the [[Place:Mediterranean Sea|Mediterranean Sea]]. Skipjack makes up about 60 percent of the catch, followed by yellowfin (24 percent), bigeye (10 percent), albacore (5 percent), and bluefin the remainder. Purse-seines take about 62 percent of the world production, longline about 14 percent, pole and line about 11 percent, and a variety of other gears the remainder.<ref name="ISSF"/>}}
The Australian government alleged in 2006 that {{wipe|Japan}} had illegally overfished southern bluefin by taking 12,000 to 20,000 tonnes per year instead of the agreed upon 6,000 tonnes; the value of such overfishing would be as much as US$2&nbsp;billion.<ref>{{cite news|url=http://www.abc.net.au/news/2006-10-16/bluefin-tuna-plundering-catches-up-with-japan/1286956 |last=Bradford |first=Gillian |title=Bluefin Tuna Plundering Catches Up With Japan |publisher=ABC News |date=16 October 2006 |access-date=11 August 2013}}</ref> Such overfishing has severely damaged bluefin stocks.<ref>{{cite news |url=https://www.washingtonpost.com/wp-dyn/content/article/2009/11/28/AR2009112801066.html |last=Eilperin |first=Juliet |title=Global approach now favored for marine conservation |newspaper=Washington Post |date=29 November 2009 |access-date=11 August 2013}}</ref> According to the [[Organization:World Wide Fund for Nature|WWF]], "Japan's huge appetite for tuna will take the most sought-after stocks to the brink of commercial [[Biology:Extinction|extinction]] unless fisheries agree on more rigid quotas".<ref>{{cite news
|url=https://www.theguardian.com/environment/2007/jan/22/japan.conservationandendangeredspecies
|title=Japan warned tuna stocks face extinction
|first=Justin |last=McCurry
|work=The Guardian
|date=22 January 2007
|access-date=2 April 2008
| location=London
}}</ref> Japan's Fisheries Research Agency counters that Australian and New Zealand tuna fishing companies under-report their total catches of southern bluefin tuna and ignore internationally mandated total allowable catch totals.<ref>{{cite news |last=Wright |first=Hillel |url=http://www.japantimes.co.jp/life/2011/01/09/life/are-japans-fish-lovers-eating-tuna-to-extinction/ |title=Are Japan's fish lovers eating tuna to extinction? |work=Japan Times |date=9 January 2011| page=7 |access-date=11 August 2013}}</ref>

In recent years, opening day fish auctions at Tokyo's Tsukiji fish market and Toyosu Market have seen record-setting prices for bluefin tuna, reflecting market demand. In each of 2010, 2011, 2012, 2013 and 2019, new record prices have been set for a single fish&nbsp;– the current record is 333.6&nbsp;million [[Finance:Japanese yen|japanese yen]] (US$3.1&nbsp;million) for a {{convert|278|kg|lb|abbr=on}} bluefin, or a unit price of JP¥&nbsp;1,200,000/kg (US$5,057/lb). The opening auction price for 2014 plummeted to less than 5% of the previous year's price, which had drawn complaints for climbing "way out of line".<ref>{{cite news|title=Price of tuna nosedives at famous Tokyo auction despite dwindling stocks |url=https://www.thestar.com/business/2014/01/05/price_of_tuna_nosedives_at_famous_tokyo_auction_despite_dwindling_stocks.html |newspaper=The Toronto Star|access-date=8 February 2014|date=5 January 2014}}</ref> A summary of record-setting auctions are shown in the following table (highlighted values indicate new world records):

{| class="wikitable" style="text-align:center;"
|-
! style="padding:8px;" colspan="7"| Record bluefin tuna auctions at Tokyo's Tsukiji fish market and Toyosu Market
|-
! style="padding:0; background:#ffd7d7; color:black;" colspan="7"| <small>(Highlighted field indicates new record price for a single fish)</small>
|-
! style="padding:0 8px; border-bottom:2px solid black;" rowspan="2"| Year
! style="padding:0 8px; border-bottom:2px solid black;" rowspan="2"| Total<br/>weight
! style="padding:0 8px;" colspan="2"| Total sale
! style="padding:0 8px;" colspan="2"| Unit price
! style="padding:0 8px; border-bottom:2px solid black;" rowspan="2"| Source
|-
! style="padding:0 8px; border-bottom:2px solid black;"| ([[Finance:Japanese yen|JP ¥]])
! style="padding:0 8px; border-bottom:2px solid black;"| (US $)
! style="padding:0 8px; border-bottom:2px solid black;"| (¥ / kg)
! style="padding:0 8px; border-bottom:2px solid black;"| ($ / lb)
|-
| style="padding:0;" 8px;| '''2001'''
| style="padding:0;" 8px;| {{convert|202|kg|lb|abbr=on|disp=br()}}
| style="padding:0 8px; background:#ffd7d7; color:black;"| '''¥20.2&nbsp;million'''
| style="padding:0 8px; background:#ffd7d7; color:black;"| '''$173,600'''
| style="padding:0 8px; background:#ffd7d7; color:black;"| '''¥100,000 / kg'''
| style="padding:0 8px; background:#ffd7d7; color:black;"| '''$386 / lb'''
|<ref name="bigtuna" />
|-
| '''2010'''
| {{convert|232|kg|lb|abbr=on|disp=br()}}
| ¥16.28&nbsp;million
| style="background:#ffd7d7; color:black;"| '''$175,000'''
| ¥70,172 / kg
| $343 / lb
|<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/asia-pacific/8440758.stm |title=Tuna hits highest price in nine years at Tokyo auction |work=BBC News |date=5 January 2010 |access-date=19 September 2012 |first=Roland |last=Buerk}}</ref>
|-
| '''2011'''
| {{convert|342|kg|lb|abbr=on|disp=br()}}
| style="background:#ffd7d7; color:black;"| '''¥32.49&nbsp;million'''
| style="background:#ffd7d7; color:black;"| '''$396,000'''
| ¥95,000 / kg
| style="background:#ffd7d7; color:black;"| '''$528 / lb'''
|<ref name="bigtuna">{{cite web|title=Fish story: Big tuna sells for record $396,000|url=http://www.nbcnews.com/id/40921151|publisher=NBCNews.com|access-date=19 September 2012|date=5 January 2011}}</ref>
|-
| '''2012'''
| {{convert|269|kg|lb|abbr=on|disp=br()}}
| style="background:#ffd7d7; color:black;"| '''¥56.49&nbsp;million'''
| style="background:#ffd7d7; color:black;"| '''$736,000'''
| style="background:#ffd7d7; color:black;"| '''¥210,000 / kg'''
| style="background:#ffd7d7; color:black;"| '''$1,247 / lb'''
|<ref>{{cite web|title=A single fish sells for nearly three-quarters of a million dollars|url=http://www.nbcnews.com/id/45882262|publisher=NBCNews.com|access-date=19 September 2012|date=5 January 2012}}</ref>
|-
| '''2013'''
| {{convert|221|kg|lb|abbr=on|disp=br()}}
| style="background:#ffd7d7; color:black;"| '''¥155.4&nbsp;million'''
| style="background:#ffd7d7; color:black;"| '''$1.76&nbsp;million'''
| style="background:#ffd7d7; color:black;"| '''¥703,167 / kg'''
| style="background:#ffd7d7; color:black;"| '''$3,603 / lb'''
|<ref>{{cite news|title=A bluefin tuna sells for record $1.76M in Tokyo|url=https://www.usatoday.com/story/news/world/2013/01/04/bluefin-tuna-tokyo-sushi/1810557//|publisher=usatoday.com|access-date=4 January 2013|date=4 January 2013}}</ref>
|-
| '''2019'''
| {{convert|278|kg|lb|abbr=on|disp=br()}}
| style="background:#ffd7d7; color:black;"| '''¥333.6&nbsp;million'''
| style="background:#ffd7d7; color:black;"| '''$3.1&nbsp;million'''
| style="background:#ffd7d7; color:black;"| '''¥1,200,000 / kg'''
| style="background:#ffd7d7; color:black;"| '''$5,057 / lb'''
|<ref>{{Cite news|url=https://www.reuters.com/article/us-tuna-auction-idUSKCN1OZ056|title=Tuna sells for record $3 million in auction at Tokyo's new fish market |date=2019-01-05|work=Reuters |df=dmy-all|access-date=2019-09-04|language=en}}</ref>
|}

In November 2011, a different record was set when a fisherman in {{wipe|Massachusetts}} caught an {{convert|881|lb|kg|abbr=on}} tuna. It was captured inadvertently using a dragnet. Due to the laws and restrictions on tuna fishing in the United States, federal authorities impounded the fish because it was not caught with a rod and reel. Because of the tuna's deteriorated condition as a result of the trawl net, the fish sold for just under $5,000.<ref>{{cite web|url=https://news.yahoo.com/blogs/sideshow/man-catches-881-pound-tuna-seized-feds-194650751.html |title=Man catches 881-pound tuna, seized by feds &#124; The Sideshow&nbsp;– Yahoo! News |publisher=News.yahoo.com |df=dmy-all |date=2011-11-15 |access-date=2012-06-16}}</ref>

<gallery class="center" widths="200">
File:TunaFish.JPG|Tuna being weighed on Greek quay-side
File:Tsukiji Fish market and Tuna edit.jpg|Tuna at Tsukiji fish market, Tokyo
File:Tuna cut half japan.jpg|Tuna cut in half for processing at Tsukuji fish market
</gallery>

===Methods===
{{external media
|float=right
|width=240px
|video1=[https://www.youtube.com/watch?v=i5mMI8t7vV0&feature=channel Tuna pole and line fishing] ''BBC Two''
}}

Besides for edible purposes, many tuna species are caught frequently as game, often for recreation or for contests in which money is awarded based on weight. Larger specimens are notorious for putting up a fight while hooked, and have been known to injure people who try to catch them, as well as damage their equipment.

* [[History:Phoenicia|Phoenicia]]n technique for trapping and catching [[Biology:Atlantic bluefin tuna|Atlantic bluefin tuna]] called ''[[Biology:Almadraba|Almadraba]]'', still used today in Portugal, Spain, Morocco and Italy which uses a maze of nets. In Sicily, the same method is called ''Tonnara''.
* Fish farming (cage system)<ref name=doolette/>
* Tuna ranching
* Longline fishing
* Purse seines
* Pole and line
* Harpoon gun
* Big game fishing
* [[Engineering:Fish aggregating device|Fish aggregating device]]

===Association with whaling===
In 2005, Nauru, defending its vote from Australian criticism at that year's meeting of the International Whaling Commission, argued that some [[Biology:Whale|whale]] species have the potential to devastate Nauru's tuna stocks, and that Nauru's food security and economy relies heavily on fishing.<ref>{{cite web|last=Dorney |first=Sean |url=http://www.abc.net.au/news/2005-06-28/nauru-defends-whaling-vote/2046680 |title=Nauru defends whaling vote. 28/06/2005. ABC News Online |publisher=Abc.net.au |df=dmy-all |date=2005-06-28 |access-date=2012-04-12}}</ref> Despite this, Nauru does not permit whaling in its own waters and does not allow other fishing vessels to take or intentionally interact with marine mammals in its Exclusive Economic Zone. In 2010 and 2011, Nauru supported Australian proposals<ref name=Aus_PS_mammal>{{cite web|last=Western and Central Pacific Fisheries Commission |title=Australia Proposals to Address the Impact of Purse Seine Fishing Activity on Cetaceans |url=http://wcpfc.int/system/files/documents/meetings/regular-sessions-commission/eighth-regular-session/delegation-proposals-and-paper/WCPFC8-2011-DP-15B-%28Rev-2%29-Australia-Proposals-Address-Impact-Purse-Seine-Fishing-Activity-Cetaceans.pdf |publisher=WCPFC |access-date=11 April 2012 |url-status=dead |archive-url=https://web.archive.org/web/20121101065208/http://wcpfc.int/system/files/documents/meetings/regular-sessions-commission/eighth-regular-session/delegation-proposals-and-paper/WCPFC8-2011-DP-15B-%28Rev-2%29-Australia-Proposals-Address-Impact-Purse-Seine-Fishing-Activity-Cetaceans.pdf |archive-date=1 November 2012}}</ref> for a western Pacific-wide ban on tuna purse-seining in the vicinity of marine mammals&nbsp;– a measure which was agreed by the Western and Central Pacific Fisheries Commission at its eighth meeting in March 2012.

===Association with dolphins===
[[Biology:Dolphin|Dolphin]]s swim beside several tuna species. These include yellowfin tuna in the eastern Pacific Ocean, but not [[Biology:Albacore|albacore]]. Tuna schools are believed to associate themselves with dolphins for protection against sharks, which are tuna predators.<ref>{{cite web |url=http://journalism.berkeley.edu/projects/border/ensenada.html |title=ENSENADA: El Puerto del Atun |publisher=Journalism.berkeley.edu |df=dmy-all |access-date=2010-09-22 |url-status=dead |archive-url=https://web.archive.org/web/20100524134557/http://journalism.berkeley.edu/projects/border/ensenada.html |archive-date=2010-05-24}}</ref>

Commercial fishing vessels used to exploit this association by searching for dolphin pods. Vessels would encircle the pod with nets to catch the tuna beneath.<ref>{{cite web|title=Dolphin-safe tuna|publisher=Whale and Dolphin Conservation|url=http://www.wdcs-na.org/text/story_details.php?select=308|url-status=dead|archive-url=https://web.archive.org/web/20130927135421/http://www.wdcs-na.org/text/story_details.php?select=308 |df=dmy-all |archive-date=2013-09-27}}</ref> The nets were prone to entangling dolphins, injuring or killing them. Public outcry and new government regulations, which are now monitored by NOAA have led to more dolphin-friendly methods, now generally involving lines rather than nets. There are neither universal independent inspection programs nor verification of dolphin safety, so these protections are not absolute. According to Consumers Union, the resulting lack of accountability means claims of tuna that is "[[Biology:Dolphin safe label|dolphin safe]]" should be given little credence.

Fishery practices have changed to be dolphin friendly, which has caused greater bycatch including [[Biology:Shark|shark]]s, [[Biology:Turtle|turtle]]s and other oceanic fish. Fishermen no longer follow dolphins, but concentrate their fisheries around floating objects such as fish aggregation devices, also known as FADs, which attract large populations of other organisms. Measures taken thus far to satisfy the public demand to protect dolphins can be potentially damaging to other species as well.<ref>{{cite web|publisher=Southern Fried Science| title=The ecological disaster that is dolphin safe tuna | date=16 February 2009 |url=http://southernfriedscientist.wordpress.com/2009/02/16/the-ecological-disaster-that-is-dolphin-safe-tuna/}}</ref>

===Aquaculture===
Increasing quantities of high-grade tuna caught at sea are reared in net pens and fed bait fish. In Australia, former fishermen raise [[Biology:Southern bluefin tuna|southern bluefin tuna]] (''Thunnus maccoyii'') and another bluefin species.<ref name=doolette>{{cite journal
|author1=Doolette, DJ
|author2=Craig, D
|name-list-style=amp
|title=Tuna farm diving in South Australia
|journal=South Pacific Underwater Medicine Society Journal
|volume=29
|issue=2
|year=1999
|issn=0813-1988
|oclc=16986801
|url=http://archive.rubicon-foundation.org/6006
|access-date=2008-08-17 |df=dmy-all
|archive-url=https://web.archive.org/web/20100107101138/http://archive.rubicon-foundation.org/6006
|archive-date=2010-01-07
|url-status=usurped
}}</ref> Farming its close relative, the [[Biology:Atlantic bluefin tuna|Atlantic bluefin tuna]], ''Thunnus thynnus'', is beginning in the Mediterranean, [[Earth:North America|North America]] and Japan. Hawai{{Okina}}i approved permits for the first U.S. offshore farming of [[Biology:Bigeye tuna|bigeye tuna]] in water {{Convert|1300|ft|m}} deep in 2009.<ref>
{{cite news
|url=http://phys.org/news175693106.html
|title=Hawaii regulators approve first US tuna farm
|last=McAvoy
|first=Audrey
|agency=Associated Press
|date=24 October 2009
|access-date=11 August 2013
}}</ref>

Japan is the biggest tuna consuming nation and is also the leader in tuna farming research.<ref>
{{cite web
|publisher=LiveScience
|url=http://www.livescience.com/animals/080317-sl-tuna-farming.html
|title=Breeding the Overfished Bluefin Tuna
|author=Susannah F. Locke
|date= 17 March 2008
|access-date=13 May 2013
}}</ref> Japan first successfully farm-hatched and raised bluefin tuna in 1979. In 2002, it succeeded in completing the reproduction cycle and in 2007, completed a third generation.<ref>
{{cite news |url=http://www.taipeitimes.com/News/editorials/archives/2006/09/30/2003329854 |title=The holy grail of fish breeding
}}</ref><ref>{{cite web|url=http://www.flku.jp/english/aquaculture/index.html |title=Cultivation, seedling production, and selective breeding of bluefin tuna and other fish at the Kinki University Fisheries Laboratory |publisher=Flku.jp |df=dmy-all |access-date=2010-09-22}}</ref><ref>{{cite news| url=http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/05/21/FDI910LR9P.DTL&type=printable | first=Carolyn | last=Jung |df=dmy-all | date=2008-05-21 | work=The San Francisco Chronicle | title=The rarest tuna of all&nbsp;– Japan's farmed Kindai}}</ref> The farm breed is known as Kindai tuna. Kindai is the contraction of Kinki University in Japanese (Kinki daigaku).<ref>{{cite web|last=Raisfeld |first=Robin |url=http://nymag.com/restaurants/features/46633/ |title=Can a Farmed Bluefin Tuna Save the Planet? – New York Magazine |publisher=Nymag.com  |df=dmy-all |date=2008-05-04 |access-date=2012-06-16}}</ref> In 2009, Clean Seas, an Australian company which has been receiving assistance from Kinki University<ref>{{cite web|url=http://www.fnarena.com/index2.cfm?type=dsp_newsitem&n=4213142B-1871-E587-E13DAA02FD0A4316 |title=FNArena |publisher=FNArena |df=dmy-all |date=2009-05-15 |access-date=2010-09-22}}</ref><ref>{{cite web |url=http://www.abc.net.au/cgi-bin/common/printfriendly.pl?http://www.abc.net.au/stateline/sa/content/2005/s1509579.htm |title=Stateline South Australia |publisher=Abc.net.au |df=dmy-all |access-date=2010-09-22 |archive-url=https://web.archive.org/web/20121113102602/http://www.abc.net.au/cgi-bin/common/printfriendly.pl?http%3A%2F%2Fwww.abc.net.au%2Fstateline%2Fsa%2Fcontent%2F2005%2Fs1509579.htm |archive-date=2012-11-13 |url-status=dead}}</ref><ref>{{Cite news | url=http://www.news.com.au/adelaidenow/story/0,22606,24389186-913,00.html | title=Clean Seas teams up with Japan's Kinki Uni for tuna research | first=Nigel | last=Austin | df=dmy-all | date=2008-09-23 | work=The Advertiser | access-date=24 November 2009 | archive-date=2 December 2012 | archive-url=https://archive.today/20121202225644/http://www.adelaidenow.com.au/business/sa-business-journal/clean-seas-signs-tuna-research-deal/story-e6fredel-1111117560776 | url-status=dead }}</ref> managed to breed southern bluefin tuna in captivity and was awarded the second place in World's Best Invention of 2009 by ''Time'' magazine.<ref name=tankbred>{{cite news|title=The Tank-Bred Tuna|url=http://www.time.com/time/specials/packages/article/0,28804,1934027_1934003_1933946,00.html|archive-url=https://web.archive.org/web/20091115062251/http://www.time.com/time/specials/packages/article/0,28804,1934027_1934003_1933946,00.html|url-status=dead|archive-date=15 November 2009|work=The 50 Best Inventions of 2009|publisher=Time.com|access-date=21 January 2013 |df=dmy-all |date=2009-11-12}}</ref><ref>{{cite web|title=Aussies Win 'Best Invention' Award|url=http://www.thinkingaustralia.com/news/brief_view.asp?id=1525|publisher=ThinkingAustralia.com|access-date=21 January 2013|url-status=dead|archive-url=https://web.archive.org/web/20130403110610/http://www.thinkingaustralia.com/news/brief_view.asp?id=1525|archive-date=3 April 2013}}</ref>

==Food==
[[File:Grilled Tuna.jpg|thumb|A grilled tuna steak]]

===Fresh and frozen===
The fresh or frozen flesh of tuna is widely regarded as a delicacy in most areas where it is shipped, being prepared in a variety of ways. When served as a steak, the meat of [[Biology:Tuna#Taxonomy|most species]] is known for its thickness and tough texture. In the U.K., supermarkets began flying in fresh tuna steaks in the late 1990s, which helped to increase the popularity of using fresh tuna in cooking; by 2009, celebrity chefs regularly featured fresh tuna in salads, wraps, and char-grilled dishes.<ref name="auto">{{cite web |url=https://www.independent.co.uk/life-style/food-and-drink/features/how-tuna-conquered-the-world-1700127.html |title=How Tuna Conquered the World |last=Hickman |first=Martin |date=9 June 2009 |website=www.independent.co.uk |publisher=The Independent |access-date=30 January 2019 |archive-date=31 January 2019 |archive-url=https://web.archive.org/web/20190131100056/https://www.independent.co.uk/life-style/food-and-drink/features/how-tuna-conquered-the-world-1700127.html |url-status=dead }}</ref>

====Served raw====
Various species of tuna are often served raw in Japanese cuisine as sushi or sashimi.<ref name="auto"/>

Commercial sashimi tuna may have their coloration fixated by pumping [[Chemistry:Carbon monoxide|carbon monoxide]] (CO) into bags containing the tuna, and holding it at 4&nbsp;°C. For a 2-inch tuna steak, this requires 24 hours. The fish is then vacuum sealed and frozen. In Japan, color fixation using CO is prohibited.<ref name="HFF">{{cite book|url=https://books.google.com/books?id=Xr6hTgLRoLIC&pg=PA328|title=Handbook of Frozen Foods|publisher=CRC Press|author=Hui, Y. H. |display-authors=0 |year=2004|page=328|isbn=0203022009}}</ref>

<gallery class="center" heights="85px"> Tuna consumption increases the risk of getting cancer.<ref>{{cite web|url=https://www.researchgate.net/project/Tuna-causes-cancer|title=Tuna causes cancer|website=ResearchGate}}</ref>
File:Tuna_Sushi.jpg|{{center|Sushi}}
File:Tuna salad 001.jpg|{{center|Tuna salad}}
File:tuna steak.JPG|{{center|Tuna steak served in a French bistro}}
File:Tekkadon_001.jpg|{{center|Tekkadon}}
File:Katsuobushi 02.jpg|{{center|Katsuobushi shavings}}
File:Mojama de atun.JPG|{{center|Mojama}}
</gallery>

===Canned===
[[File:Canned and packaged tuna on supermarket shelves.jpg|thumb|right|Canned tuna on sale at a supermarket|alt=Small cans on grocery shelves|275x275px]]

Tuna is canned in edible oils, in [[Earth:Brine|brine]], in water, and in various sauces. Tuna may be processed and labeled as "solid", "chunked" ("chunk") or "flaked". When tuna is canned and packaged for sale, the product is sometimes called '''tuna fish''' (U.S.), a [[Social:Calque|calque]] (loan translation) from the [[Social:German language|German]] ''Thunfisch''. Canned tuna is sometimes used as food for pets, especially [[Biology:Cat|cat]]s.

;Australia
Canned tuna was first produced in Australia in 1903 and quickly became popular.<ref name=Choice2004>''Choice'': Jan/Feb 2004.</ref>

In the early 1980s canned tuna in Australia was most likely [[Biology:Southern bluefin tuna|southern bluefin]], {{As of|2003|lc=on}} it was usually yellowfin, [[Biology:Skipjack tuna|skipjack]], or tongol (labelled "northern bluefin" or "longtail").<ref name="Choice2004" />

Australian standards once required cans of tuna to contain at least 51% tuna, but those regulations were dropped in 2003.<ref name="Choice2003">''Choice'', August 2003.</ref><ref>[http://www.choice.com.au/viewArticle.aspx?id=104101&catId=100406&tid=100008&p=2&title=Test:+Canned+tuna+(archived) Test: Canned tuna (archived) Canned or conned?] {{webarchive|url=https://web.archive.org/web/20080801143345/http://www.choice.com.au/viewArticle.aspx?id=104101&catId=100406&tid=100008&p=2&title=Test%3A+Canned+tuna+%28archived%29 |date=1 August 2008}}</ref> The remaining weight is usually oil or water.

;United States
The product became more plentiful in the United States in the late 1940s. In 1950, 8,500,000 pounds of canned tuna were produced, and the U.S. Department of Agriculture classified it as a "plentiful food".<ref name=NYT>{{cite news | last =Casa-Emellosthe| first =Ruth P. | title =News of Food: Tuna Provides Tempting Dishes; Canned Fish Plentiful Now and a Good Buy for Budget-Minded | newspaper ={{wipe|New York Times}} | location = | pages = 30| language = | publisher = | date =March 1, 1951 | url =https://timesmachine.nytimes.com/timesmachine/1951/03/01/82093669.html?pageNumber=30 | accessdate =April 17, 2021 }}</ref>

In the United States, 52% of canned tuna is used for sandwiches; 22% for tuna salads; and 15% for tuna casseroles and dried, prepackaged [[Finance:Meal kit|meal kit]]s, such as [[Company:General Mills|General Mills]]'s Tuna Helper line.<ref name="modernmarvels">"Tuna". ''Modern Marvels'', 4 February 2010.</ref> Other canned tuna dishes include tuna melts (a type of sandwich where the tuna is mixed with mayonnaise and served on bread with cheese melted on top); salade niçoise (a salad made of tuna, olives, green beans, potatoes, hard-boiled eggs and anchovy dressing); and tuna burgers (served on buns).

In the United States, the [[Organization:Food and Drug Administration|Food and Drug Administration]] (FDA) regulates canned tuna (see part ''c'').<ref>{{cite web|url=http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=161.190 |title=CFR&nbsp;– Code of Federal Regulations Title 21 |publisher=Accessdata.fda.gov |df=dmy-all |access-date=2010-09-22}}</ref>

;Precooked
As tunas are often caught far from where they are processed, poor interim conservation can lead to spoilage. Tuna is typically gutted by hand, and later precooked for prescribed times of 45 minutes to three hours. The fish are then cleaned and filleted, canned (and sealed), with the dark lateral blood meat often separately canned for pet food (cat or dog). The sealed can is then heated under pressure (called "[[Physics:Pressure cooking|retort cooking]]") for 2–4 hours.<ref>{{cite web
|url=http://www.dol.gov/whd/as/sec3.htm
|title=The tuna processing industry
|publisher=U.S. Department of Labor
|access-date=11 August 2013
|archive-url=https://web.archive.org/web/20130812124832/http://www.dol.gov/whd/as/sec3.htm
|archive-date=12 August 2013
|url-status=dead
}}</ref> This process kills any bacteria, but retains the [[Chemistry:Histamine|histamine]] that [[Medicine:Scombroid food poisoning|may have been produced by those bacteria]], and so may still taste spoiled. The international standard sets the maximum histamine level at 200 milligrams per kilogram. An Australian study of 53 varieties of unflavored canned tuna found none to exceed the safe histamine level, although some had "off" flavors.<ref name="Choice2004" />

;Light and white
In some markets, depending upon the color of the flesh of the tuna species, the can is marked as "light" or "white" meat, with "light" meaning a greyish pink color and "white" meaning a light pink color. In the United States, only [[Biology:Albacore|albacore]] can legally be sold in canned form as "white meat tuna";<ref>Ellis, Richard.  ''Tuna: A Love Story.'' New York: Random House, 2009, p. 119. {{ISBN|0-307-38710-0}}</ref> in other countries, [[Biology:Yellowfin tuna|yellowfin]] is also acceptable.

; Ventresca tuna{{anchor|Ventresca tuna|ventresca tuna}}
Ventresca tuna (from ''ventre'', the Italian word for belly),<ref name="Rosengarten-2003-Ventresca">{{cite web |last1=Rosengarten |first1=David |title=Name That Tuna! The Little-Known, Sexy Varieties that Are Vastly Superior to the Supermarket Cans |url=https://www.wine4food.com/food/name-that-tuna-the-little-known-sexy-varieties-that-are-vastly-superior-to-the-supermarket-cans/ |website=Wine4Food |access-date=14 May 2021 |archive-url=https://web.archive.org/web/20210514215614/https://www.wine4food.com/food/name-that-tuna-the-little-known-sexy-varieties-that-are-vastly-superior-to-the-supermarket-cans/ |archive-date=14 May 2021 |date=31 July 2012 |quote=What is ventresca? The name comes from the Italian word for belly, which is "ventre." Yup, you guessed it, ventresca is canned tuna made from the tuna's belly, from the sexy, velvety hunk known in sushi bars as "toro." Happily, there are a good many ventresca brands in the U.S. right now from Italy and Spain. (Originally Published: ROSENGARTEN REPORT, April 2003.)}}</ref> is a luxury canned tuna,<ref name="Luxury-splendidtable">{{cite web |title=Luxury Canned Tuna |url=https://www.splendidtable.org/story/2010/11/18/luxury-canned-tuna |website=www.splendidtable.org |access-date=14 May 2021 |archive-url=https://web.archive.org/web/20210514214210/https://www.splendidtable.org/story/2010/11/18/luxury-canned-tuna |archive-date=14 May 2021 |date=November 18, 2010 |quote=Ventresca Tuna: This tuna comes from the belly of the fish, that velvety chunk known in sushi bars as toro. It has deep, buttery, complex flavors and a creamy texture. This one stands alone. The less you do to it the better. Be prepared to pay dearly for this unabashed luxury}}</ref> from the fatty [[Biology:Bluefin tuna|bluefin tuna]] belly, also used in sushi as toro.<ref name="Fraioli2008">{{cite book |last1=Fraioli |first1=James O. |last2=Sato |first2=Chef Kaz |date=2008 |title=The Complete Idiot's Guide to Sushi and Sashimi |url=http://idiotsguides.com |location=New York, NY |publisher=Alpha Books |isbn=978-1-59257-782-8}}</ref><ref name ="SushiEncyc">{{cite web |url=http://www.sushiencyclopedia.com/sushi_menu.html |title=Sushi Menu |author=<!--Staff writer(s); no by-line.--> |date=2007 |website=Sushi Encyclopedia |access-date=12 February 2016 |quote=The sushi menu consists of basic Edo style sushi and they are grouped in their styles. |archive-date=20 May 2017 |archive-url=https://web.archive.org/web/20170520055030/http://www.sushiencyclopedia.com/sushi_menu.html |url-status=dead }}</ref>

====Nutrition====
{{nutritional value
| name           = Tuna, light, canned in oil, drained solids
| kJ             = 830
| water          = 60 g
| protein        = 29 g
| fat            = 8 g
| carbs          = 0 g
| iron_mg        = 1.4
| calcium_mg     = 13
| magnesium_mg   = 31
| phosphorus_mg  = 311
| potassium_mg   = 207
| zinc_mg        = 0.9
| vitA_ug        = 23
| vitD_iu        = 269
| choline_mg     = 29
| right          = 1
| source_usda    = 1
}}

Canned light tuna in oil is 29% [[Biology:Protein|protein]], 8% [[Chemistry:Fat|fat]], 60% water, and contains no [[Chemistry:Carbohydrate|carbohydrate]]s, while providing 200 [[Calorie|calorie]]s in a 100 gram reference amount (table). It is a rich source (20% or more of the Daily Value, DV) of [[Chemistry:Phosphorus|phosphorus]] (44% DV) and [[Chemistry:Vitamin D|vitamin D]] (45% DV), and a moderate source of [[Chemistry:Iron|iron]] (11% DV).

===Mercury and health===
Mercury content in tuna can vary widely. Among those calling for improved warnings about mercury in tuna is the American Medical Association, which adopted a policy that physicians should help make their patients more aware of the potential risks.<ref>{{cite news | url=http://www.chicagotribune.com/features/health/chi-0512130114dec13,0,4864620,full.story | work=Chicago Tribune | title=How safe is tuna? | first1=Sam | last1=Roe | first2=Michael | last2=Hawthorne | date=2005-12-13 | url-status=dead | archive-url=https://web.archive.org/web/20091126023316/http://www.chicagotribune.com/features/health/chi-0512130114dec13,0,4864620,full.story |df=dmy-all |archive-date=2009-11-26}}</ref> A study published in 2008 found that mercury distribution in the meat of farmed tuna is inversely related to the lipid content, suggesting that higher lipid concentration within edible tissues of tuna raised in captivity might, other factors remaining equal, have a diluting effect on mercury content.<ref>{{cite journal
 | last1 = Balshaws  | first1 = S.
 | first2 =  J.W. | last2= Edwards 
 | first3= K.E. | last3= Ross
 | first4= B.J. | last4= Daughtry
 | title = Mercury distribution in the muscular tissue of farmed southern bluefin tuna (''Thunnus maccoyii'') is inversely related to the lipid content of tissues
 | journal = Food Chemistry  | volume = 111  | issue = 3  | pages = 616–621
 | date = December 2008| doi = 10.1016/j.foodchem.2008.04.041}}</ref> Mackerel tuna is one species of tuna that is lower in mercury concentration than skipjack or yellowfin,<ref>{{cite journal|last1=Sompongchaiyakul|first1=Penjai|last2=Hantow1|date=2010|title=An assessment of mercury concentration in fish tissues caught from three compartments of the Bay of Bengal|url=https://pdfs.semanticscholar.org/aa1b/e647c6109fe46c005c6797f6adb28b562bfc.pdf|archive-url=https://web.archive.org/web/20180821062638/https://pdfs.semanticscholar.org/aa1b/e647c6109fe46c005c6797f6adb28b562bfc.pdf|url-status=dead|archive-date=2018-08-21|journal=Harper S, O'Meara D, Booth S, Zeller D, Pauly D (Eds) Fisheries Catches for the Bay of Bengal Large Marine Ecosystem Since 1950, Vol 16, Report to the Bay of Bengal Large Marine Ecosystem Project|pages=1|s2cid=41523999}}</ref> but this species is known as "black meat" or "dark meat" tuna, which is a lower grade for canning because of the color, unfavorable flavor, and poor yield.<ref>{{cite journal|vauthors=Balachandran KK, Vijayan PK, Joseph J|year=1982|title=Improving the acceptability of canned Mackerel tuna (''Euthynnus affinis'')|url=http://aquaticcommons.org/18382/1/FT19.1_059.pdf |archive-url=https://web.archive.org/web/20180821093834/http://aquaticcommons.org/18382/1/FT19.1_059.pdf |archive-date=2018-08-21 |url-status=live|journal=Fish Technology|volume=19|pages=59–60}}</ref>

In March 2004, the United States [[Organization:Food and Drug Administration|FDA]] issued guidelines recommending that pregnant women, nursing mothers, and children limit their intake of tuna and other predatory fish.<ref>{{cite web
| title = What You Need to Know About Mercury in Fish and Shellfish
| url = http://www.cfsan.fda.gov/~dms/admehg3.html
| date = March 2004
| access-date = 2007-05-19
| archive-date = 19 May 2007
| archive-url = https://web.archive.org/web/20070519060018/http://www.cfsan.fda.gov/~dms/admehg3.html
| url-status = dead
}}</ref> The Environmental Protection Agency provides guidelines on how much canned tuna is safe to eat. Roughly speaking, the guidelines recommend one {{convert|6|oz|g|adj=on}} can of light tuna per week for individuals weighing less than {{convert|110|lbs|kg}}, and two cans per week for those who weigh more.<ref>{{cite web
| title = PROTECT YOURSELF AND YOUR FAMILY: Eating Tuna Safely
| url = http://www.nrdc.org/health/effects/mercury/tuna.asp
| date = 2012-04-02
| access-date = 2012-04-02
}}</ref> In 2007, it was reported that some canned light tuna such as [[Biology:Yellowfin tuna|yellowfin tuna]]<ref>{{cite news
|title=FDA to check tuna
|url=http://articles.chicagotribune.com/2005-12-31/news/0512310211_1_light-tuna-tuna-foundation-low-mercury
|access-date=2007-06-21 |df=dmy-all
| work=Chicago Tribune
}}</ref> is significantly higher in mercury than skipjack, and caused Consumers Union and other activist groups to advise pregnant women to refrain from consuming canned tuna.<ref>{{cite web
| title = Mercury in tuna
| url = http://www.consumerreports.org/cro/food/tuna-safety/overview/0607_tuna_ov.htm
| date = June 2006
| df = dmy-all
| access-date = 2007-05-19
| archive-date = 10 April 2007
| archive-url = https://web.archive.org/web/20070410020238/http://www.consumerreports.org/cro/food/tuna-safety/overview/0607_tuna_ov.htm
| url-status = dead
}}</ref> In 2009, a California appeals court upheld a ruling that canned tuna does not need warning labels as the [[Chemistry:Methylmercury|methylmercury]] is naturally occurring.<ref>{{cite court |litigants=People ex rel. Brown v. Tri-Union Seafoods, LLC |vol=171 |reporter=Cal.App.4th |opinion=1549 |pinpoint= |court=Cal. App. Ct. |date=2009 |url=https://scholar.google.com/scholar_case?hl=en&as_sdt=40000006&case=14761508866702574858&scilh=0 |access-date=7 October 2014 |quote=}}</ref>

A January 2008 report revealed potentially dangerous levels of [[Chemistry:Mercury (element)|mercury]] in certain varieties of sushi tuna, reporting levels "so high that the Food and Drug Administration could take legal action to remove the fish from the market."<ref>{{cite news
|url=https://www.nytimes.com/2008/01/23/dining/23sushi.html?ref=nyregion
|title=High Mercury Levels Are Found in Tuna Sushi
|newspaper=New York Times
|date=23 January 2008
|access-date=11 September 2009
| first=Marian
| last=Burros
}}</ref>

==Management and conservation==
[[File:Tuna-lifecycle1.jpg|thumb|400px|{{center|Life cycle}}]]

The main tuna fishery management bodies are the [[Earth:Western and Central Pacific Fisheries Commission|Western and Central Pacific Fisheries Commission]], the Inter-American Tropical Tuna Commission, the [[Earth:Indian Ocean Tuna Commission|Indian Ocean Tuna Commission]], the International Commission for the Conservation of Atlantic Tunas, and the Commission for the Conservation of Southern Bluefin Tuna.<ref>{{cite news
| title = WWF demands tuna monitoring system
| url = http://www.theage.com.au/news/World/WWF-demands-tuna-monitoring-system/2007/01/19/1169095972203.html
| date = 2007-01-19 |df=dmy-all
| access-date = 2008-05-19
| location=Melbourne
| work=The Age
}}</ref> The five gathered for the first time in Kobe, {{wipe|Japan}} in January 2007. Environmental organizations made submissions<ref>{{cite web|url=http://oceans.greenpeace.org/en/documents-reports/rfmo-kobe |title=Briefing: Joint Tuna RFMO Meeting, Kobe 2007 |df=dmy-all |date=2007-01-23 |access-date=2008-05-19 |url-status=dead |archive-url=https://web.archive.org/web/20080323185155/http://oceans.greenpeace.org/en/documents-reports/rfmo-kobe |archive-date=23 March 2008}}</ref> on risks to fisheries and species. The meeting concluded with an action plan drafted by some 60 countries or areas. Concrete steps include issuing certificates of origin to prevent illegal fishing and greater transparency in the setting of regional fishing quotas. The delegates were scheduled to meet at another joint meeting in January or February 2009 in Europe.<ref>{{cite web|url=http://www.abc.net.au/news/newsitems/200701/s1834563.htm |title=Conference approves global plan to save tuna stocks |website=Australian Broadcasting Corporation |date=2007-01-26 |access-date=2008-05-10 |df=dmy-all |url-status=dead |archive-url=https://web.archive.org/web/20080111070803/http://www.abc.net.au/news/newsitems/200701/s1834563.htm |archive-date=11 January 2008}}</ref>

In 2010, Greenpeace International added the [[Biology:Albacore|albacore]], [[Biology:Bigeye tuna|bigeye tuna]], [[Biology:Pacific bluefin tuna|Pacific bluefin tuna]], [[Biology:Atlantic bluefin tuna|Atlantic bluefin tuna]], [[Biology:Southern bluefin tuna|southern bluefin tuna]], and [[Biology:Yellowfin tuna|yellowfin tuna]] to its seafood red list, which are fish "commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries."<ref>{{cite web|url=http://www.greenpeace.org/international/seafood/red-list-of-species |title=Greenpeace International Seafood Red list |publisher=Greenpeace.org |date=2003-03-17 |access-date=2010-09-22 |df=dmy-all |url-status=dead |archive-url=https://web.archive.org/web/20100820034707/http://www.greenpeace.org/international/seafood/red-list-of-species |archive-date=20 August 2010}}</ref><ref>{{cite news| url=https://www.nytimes.com/2010/06/27/magazine/27Tuna-t.html | title=Tuna's End | first=Paul | last=Greenberg |df=dmy-all | date=2010-06-21 | work=The New York Times}}</ref>

Bluefin tuna have been widely accepted as being severely overfished, with some stocks at risk of collapse.<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/7040011.stm |title=Last rites for a marine marvel? |first=Richard |last=Black |work=BBC News |date=17 October 2007 |df=dmy-all |access-date=17 October 2007 }}</ref><ref>Ito, Masami, "[http://search.japantimes.co.jp/cgi-bin/nn20100831i1.html Does Japan's affair with tuna mean loving it to extinction?]", ''Japan Times'', 31 August 2010, p. 3. {{dead link|date=June 2016|bot=medic}}{{cbignore|bot=medic}}</ref> According to the International Seafood Sustainability Foundation (a global, nonprofit partnership between the tuna industry, scientists, and the [[Organization:World Wide Fund for Nature|World Wide Fund for Nature]]), Indian Ocean yellowfin tuna, Pacific Ocean (eastern and western) [[Biology:Bigeye tuna|bigeye tuna]], and North Atlantic [[Biology:Albacore|albacore]] tuna are all overfished. In April 2009, no stock of [[Biology:Skipjack tuna|skipjack tuna]] (which makes up roughly 60% of all tuna fished worldwide) was considered to be overfished.<ref>{{cite web |url=http://www.iss-foundation.org/files/e71afd66-086a-41c7-a71c-c2935687dcef/ISSF_A-2%20Summary%20(3).pdf |title=Status of the World Fisheries for Tuna: Section A-2 – Summary |publisher=ISSF |date= 15 April 2009 |df=dmy-all |access-date= 10 November 2009 |archive-url=https://web.archive.org/web/20100327022746/http://www.iss-foundation.org/files/e71afd66-086a-41c7-a71c-c2935687dcef/ISSF_A-2%20Summary%20%283%29.pdf |archive-date= 27 March 2010 }}</ref>

The BBC documentary ''South Pacific'', which first aired in May 2009, stated that, should fishing in the Pacific continue at its current rate, populations of all tuna species could collapse within five years. It highlighted huge Japanese and European tuna fishing vessels, sent to the South Pacific international waters after overfishing their own fish stocks to the point of collapse.<ref>{{cite episode |title=Fragile Paradise |series=South Pacific |credits=Produced and directed by Jonathan Clay |network=BBC |station=BBC Two |df=dmy-all |air-date=2009-06-14}}</ref>

A 2010 tuna fishery assessment report, released in January 2012 by the Secretariat of the Pacific Community, supported this finding, recommending that all tuna fishing should be reduced or limited to current levels and that limits on skipjack fishing be considered.<ref>{{cite web
|url=http://www3.cookislandsnews.com/2012/January/Wed18/environment.htm
|title=Tuna overfishing continues
|publisher=Cook Islands News
|date=12 January 2012 |df=dmy-all
|access-date=2012-05-19
|url-status=dead
|archive-url=https://web.archive.org/web/20131115074636/http://www.cookislandsnews.com/2012/January/Wed18/environment.htm
|archive-date=2013-11-15
}}</ref>

Research<ref name=":0">{{cite journal|last1=Roxy|first1=Mathew Koll |last2=Modi |first2=Aditi|last3=Murtugudde|first3=Raghu|last4=Valsala|first4=Vinu|last5=Panickal|first5=Swapna|last6=Prasanna Kumar |first6=S.|last7=Ravichandran|first7=M.|last8=Vichi|first8=Marcello|last9=Lévy|first9=Marina |df=dmy-all |date=2016-01-28 |title=A reduction in marine primary productivity driven by rapid warming over the tropical Indian Ocean|journal=Geophysical Research Letters|language=en|volume=43|issue=2|pages=2015GL066979|doi=10.1002/2015GL066979|bibcode=2016GeoRL..43..826R|issn=1944-8007|url=https://hal.archives-ouvertes.fr/hal-01259414/file/Roxy_2016_A_reduction_in.pdf |archive-url=https://web.archive.org/web/20190103110538/https://hal.archives-ouvertes.fr/hal-01259414/file/Roxy_2016_A_reduction_in.pdf |archive-date=2019-01-03 |url-status=live|doi-access=free}}</ref> indicates that increasing ocean temperatures are taking a toll on the tuna in the Indian Ocean, where rapid warming of the ocean has resulted in a reduction of marine [[Earth:Phytoplankton|phytoplankton]]. The bigeye tuna catch rates have also declined abruptly during the past half century, mostly due to increased industrial fisheries, with the ocean warming adding further stress to the fish species.<ref name=":0" />

==See also==
* Environmental impact of fishing
* Got Mercury?
* List of tuna dishes
* [[Biology:Natal homing|Natal homing]]

==References==
{{Reflist|30em}}

==Further references==
* Clover, Charles. 2004. ''The End of the Line: How Overfishing Is Changing the World and What We Eat''. Ebury Press, London. {{ISBN|0-09-189780-7}}
* FAO: Species Catalog Vol. 2 Scombrids of the World. FAO Fisheries Synopsis No. 125, Volume 2. FIR/S125 Vol. 2.{{ISBN|92-5-101381-0}}
* FAO: Review of the state of world marine fishery resources: [http://firms.fao.org/firms/resource/16001/en Tuna and tuna-like species – Global, 2005] Rome.
* Majkowski, Jacek (1995) [http://www.fao.org/docrep/009/y5852e/Y5852E08.htm#ch3.1 "Tuna and tuna-like species"] In: ''Review of the state of world marine fishery resources'', FAO Fisheries technical paper 457, FAO, Rome. {{ISBN|978-92-5-107023-9}}.
* Majkowski J, Arrizabalaga H, Carocci F and Murua H (2011) [http://www.fao.org/docrep/015/i2389e/i2389e.zip "Tuna and tuna-like species"] {{Webarchive|url=https://web.archive.org/web/20160303170625/http://www.fao.org/docrep/015/i2389e/i2389e.zip |date=3 March 2016 }} In: ''Review of the state of world marine fishery resources'', pages 227–244, FAO Fisheries technical paper 569, FAO, Rome. {{ISBN|978-92-5-107023-9}}.
* Standard of Identity for Canned Tuna (United States), Code of Federal Regulations: 21 CFR 161.190 – Canned tuna.
* Viñas J and Tudela S (2009) [http://dugi-doc.udg.edu/bitstream/10256/3594/1/Validated-Methodology.pdf "A validated methodology for genetic identification of tuna species (genus ''Thunnus'')"] ''PLoS One'', '''4'''(10): e7606.

==Further reading==
* [https://blogs.scientificamerican.com/extinction-countdown/bluefin-tuna-chinese-cobra-and-others-added-to-red-list-of-threatened-species/ Bluefin Tuna, Chinese Cobra and Others Added to Red List of Threatened Species], Scientific American, 18 November 2014
* [https://www.nsf.gov/news/news_summ.jsp?cntn_id=104543&org=NSF&from=news How Hot Tuna (and Some Sharks) Stay Warm] National Science Foundation, 27 October 2005

{{Commercial fish topics}}
{{Taxonbar|from=Q6146274}}

[[Category:Scombridae]]

{{Sourceattribution|Tuna}}