Editing Fish migration (section)

==Highly migratory species==
[[File:internationalwaters.png|right|thumb|The [[high seas]], highlighted in blue, are the seas which are outside the {{convert|200|nmi|km|abbr=on}} [[exclusive economic zone]]s]]
{{See also|Straddling stock|Bonn Convention}}

The term '''highly migratory species''' (HMS) has its origins in Article 64 of the [[United Nations Convention on the Law of the Sea]] (UNCLOS). The Convention does not provide an operational definition of the term, but in an annex (UNCLOS Annex 1) lists the species considered highly migratory by parties to the convention.<ref>[[United Nations]] Convention on the [[Law of the Sea]]:  [https://www.un.org/Depts/los/convention_agreements/texts/unclos/closindx.htm Text]</ref> The list includes: [[tuna]] and tuna-like species ([[Albacore tuna|albacore]], [[Bluefin tuna|bluefin]], [[bigeye tuna]], [[Skipjack tuna|skipjack]], [[Yellowfin tuna|yellowfin]], [[Blackfin tuna|blackfin]], [[Euthynnus alletteratus|little tunny]], [[Southern bluefin tuna|southern bluefin]] and [[Auxis rochei|bullet]]), [[wahoo]], [[Bramidae|pomfret]], [[marlin]], [[sailfish]], [[swordfish]], [[saury]] and  oceangoing [[shark]]s, [[dolphin]]s and other [[Cetacea|cetaceans]].

These high [[trophic level]] oceanodromous species undertake migrations of significant but variable distances across oceans for feeding, often on forage fish, or reproduction, and also have wide geographic distributions. Thus, these species are found both inside the {{convert|200|nmi|km|adj=on|abbr=off}} [[exclusive economic zone]]s and in the [[high seas]] outside these zones. They are [[Pelagic fish|pelagic]] species, which means they mostly live in the open ocean and do not live near the sea floor, although they may spend part of their life cycle in [[nearshore waters]].<ref>[[Pacific Fishery Management Council]]: [http://www.pcouncil.org/highly-migratory-species/background/  Background:  Highly Migratory Species]</ref>

Highly migratory species can be compared with [[straddling stock]] and [[transboundary stock]]. Straddling stock range both within an [[EEZ]] as well as in the [[high seas]]. Transboundary stock range in the EEZs of at least two countries. A stock can be both transboundary and straddling.<ref name="FAO 2007">[[FAO]] (2007) [https://agris.fao.org/agris-search/search.do?recordID=XF2016072968 Report of the FAO workshop on vulnerable ecosystems and destructive fishing in deep sea fisheries], Rome, Fisheries Report No. 829. [https://books.google.com/books?id=6jL7ZHq9GgsC&pg=PA1 HTML]</ref>

It can be challenging to determine the population structure of highly migratory species using physical tagging. Traditional genetic markers such as short-range PCR products, microsatellites and SNP-arrays have struggled to identify population structure and distinguish [[fish stocks]] from separate ocean basins. However, [[population genomics|population genomic]] research using [[Restriction site associated DNA markers|RAD]] sequencing in yellowfin tuna,<ref name="Grewe-2015">{{cite journal |doi=10.1038/srep16916 |title=Evidence of discrete yellowfin tuna (''Thunnus albacares'') populations demands rethink of management for this globally important resource |journal=Scientific Reports |volume=5 |pages=16916 |year=2015 |last1=Grewe |first1=P.M. |last2=Feutry |first2=P. |last3=Hill |first3=P.L. |last4=Gunasekera |first4=R.M. |last5=Schaefer |first5=K.M. |last6=Itano |first6=D.G. |last7=Fuller |first7=D.W.  |last8=Foster |first8=S.D.  |last9=Davies |first9=C.R. |pmid=26593698 |pmc=4655351 |bibcode=2015NatSR...516916G |doi-access=free}}</ref><ref name="Pecoraro-2018">{{cite journal |doi=10.1038/s41598-018-32331-3 |title=The population genomics of yellowfin tuna (''Thunnus albacares'') at global geographic scale challenges current stock delineation |journal=Scientific Reports |volume=8 |pages=13890 |year=2018 |last1=Pecoraro|first1=Carlo |last2=Babbucci |first2=Massimiliano |last3=Franch |first3=Rafaella |last4=Rico |first4=Ciro |last5=Papetti |first5=Chiara |last6=Chassot |first6=Emmanuel |last7=Bodin |first7=Nathalie  |last8=Cariani |first8=Alessia  |last9=Bargelloni |first9=Luca |last10=Tinti |first10=Fausto |issue=1 |pmid=30224658 |pmc=6141456 |bibcode=2018NatSR...813890P |doi-access=free}}</ref>  albacore,<ref name="Anderson-2019">{{cite journal |doi=10.1002/ece3.5554 |title=Indications of strong adaptive population genetic structure in albacore tuna (''Thunnus alalunga'') in the southwest and central Pacific Ocean |journal=Ecology and Evolution |volume=9 |issue=18 |pages=10354–10364 |year=2019 |last1=Anderson|first1=Giulia |last2=Hampton |first2=John |last3=Smith |first3=Neville |last4=Rico |first4=Ciro |pmid=31624554 |pmc=6787800 |doi-access=free}}</ref><ref name="Vaux-2021">{{cite journal |doi=10.1111/eva.13202 |title=Adaptive markers distinguish North and South Pacific Albacore amid low population differentiation |journal=Evolutionary Applications |volume=14 |issue=5 |pages=1343–1364 |year=2021 |last1=Vaux|first1=Felix |last2=Bohn|first2=Sandra |last3=Hyde|first3=John R. |last4=O'Malley |first4=Kathleen G. |pmid=34025772 |pmc=8127716 |doi-access=free}}</ref> and wahoo<ref name="Haro-Bilbao-2021">{{cite journal |doi=10.1111/jbi.14135| issn=0305-0270 |title=Global connections with some genomic differentiation occur between Indo-Pacific and Atlantic Ocean wahoo, a large circumtropical pelagic fish |journal=Journal of Biogeography |volume= 48|issue= 8|pages= 2053–2067|year=2021 |last1=Haro-Bilbao|first1=Isabel |last2=Riginos|first2=Cynthia |last3=Baldwin|first3=John D. |last4=Zischke |first4=Mitchell |last5=Tibbetts |first5=Ian R. |last6=Thia |first6=Joshua A.|s2cid=236381627 |hdl=11343/298583 |hdl-access=free }}</ref> has been able to distinguish populations from different ocean basins and reveal fine-scale population structure. Similar population genomics methods have also provided improved insight towards population structure in [[striped marlin]].<ref name="Mamoozadeh-2020">{{cite journal |doi=10.1111/eva.12892 |title=Genome-wide SNPs resolve spatiotemporal patterns of connectivity within striped marlin (''Kajikia audax''), a broadly distributed and highly migratory pelagic species |journal=Evolutionary Applications |volume=13 |issue=4 |pages=677–698 |year=2020 |last1=Mamoozadeh|first1=Nadya R. |last2=Graves |first2=John E. |last3=McDowell |first3=Jan R. |pmid=32211060 |pmc=7086058 |doi-access=free}}</ref>