Editing Atlantic cod (section)

== Fisheries ==
{{See also|Cod fisheries}}
[[File:Atlantic cod, capture production, million tonnes, 1950-2022.svg|thumb|Global capture production of Atlantic cod (''Gadus morhua'') in million tonnes from 1950 to 2022, as reported by the [[Food and Agriculture Organization|FAO]]<ref>{{Cite web |title=Fisheries and Aquaculture - Global Production |url=https://www.fao.org/fishery/en/collection/global_production?lang=en |access-date=2024-05-06 |website=Food and Agriculture Organization of the United Nations (FAO)}}</ref>]]
Atlantic cod has been targeted by humans for food for thousands of years,<ref>{{Cite journal |last1=Ólafsdóttir |first1=Guðbjörg Ásta |last2=Pétursdóttir |first2=Gróa |last3=Bárðarson |first3=Hlynur |last4=Edvardsson |first4=Ragnar |date=2017-10-27 |editor-last=Corriero |editor-first=Aldo |title=A millennium of north-east Atlantic cod juvenile growth trajectories inferred from archaeological otoliths |journal=PLOS ONE |language=en |volume=12 |issue=10 |pages=e0187134 |doi=10.1371/journal.pone.0187134 |issn=1932-6203 |pmc=5659679 |pmid=29077736|bibcode=2017PLoSO..1287134O |doi-access=free }}</ref> and with the advent of modern fishing technology in the 1950s there was a rapid rise in landings.<ref name=":3" /> Cod is caught using a variety of fishing gears including [[Bottom trawling|bottom trawls]], [[Longline fishing|demersal longlines]], [[Seine fishing|Danish seine]], [[jigging]] and [[Handline fishing|hand lines]]. The quantity of cod landed from fisheries has been recorded by many countries from around the 1950s and attempts have been made to reconstruct historical catches going back hundreds of years.<ref name=":3">{{Cite journal |last1=Schijns |first1=Rebecca |last2=Froese |first2=Rainer |last3=Hutchings |first3=Jeffrey A |last4=Pauly |first4=Daniel |date=2021-10-27 |editor-last=Raicevich |editor-first=Sasa |title=Five centuries of cod catches in Eastern Canada |url=https://academic.oup.com/icesjms/article/78/8/2675/6359257 |journal=ICES Journal of Marine Science |language=en |volume=78 |issue=8 |pages=2675–2683 |doi=10.1093/icesjms/fsab153 |issn=1054-3139|doi-access=free |hdl=11250/2833698 |hdl-access=free }}</ref> [[International Council for the Exploration of the Sea|ICES]] and [[Northwest Atlantic Fisheries Organization|NAFO]] collects landings data, alongside other data, which is used to assess the status of the population against management objectives. The landings in the eastern Atlantic frequently exceeds 1 million tonnes annually from across 16 populations/management units with landings from the Northeast Atlantic cod population and Iceland accounting for the majority of the landings, Since 1992, when the cod [[Collapse of the Atlantic northwest cod fishery|moratorium]] took effect in Canada, landings in the western Atlantic have been considerably lower than in the eastern Atlantic, generally being less than 50,000 tonnes annually.

===Northwest Atlantic cod===
{{main|Collapse of the Atlantic northwest cod fishery}}

The Northwest Atlantic cod has been regarded as heavily overfished throughout its range, resulting in a crash in the fishery in the United States and Canada during the early 1990s.

Newfoundland's northern cod fishery can be traced back to the 16th century. On average, about {{cvt|300000|t|ST}} of cod were landed annually until the 1960s, when advances in technology enabled factory trawlers to take larger catches. By 1968, landings for the fish peaked at {{cvt|800000|t|ST}} before a gradual decline set in. With the reopening of the limited cod fisheries in 2006, nearly {{cvt|2700|t|ST}} of cod were hauled in. In 2007, offshore cod stocks were estimated at 1% of what they were in 1977.<ref>{{cite news |url=https://www.cbc.ca/news/canada/newfoundland-labrador/n-l-funds-cod-fishery-research-on-15th-anniversary-of-moratorium-1.660303?ref=rss |archive-url=https://web.archive.org/web/20121104111114/http://www.cbc.ca/news/canada/newfoundland-labrador/story/2007/07/02/cod-moratorium.html?ref=rss |title=N.L. funds cod fishery research on 15th anniversary of moratorium |date=2 July 2007 |archive-date=4 November 2012 |url-status=live |publisher=[[CBC News]]}}</ref>[[File:Atlantic cod landings western Atlantic.jpg|thumb|420x420px|Landings of Atlantic cod (''Gadus morhua'') in the western Atlantic from 1960 to 2019. Data source: NAFO.]]Technologies that contributed to the collapse of Atlantic cod include engine-powered vessels and frozen food compartments aboard ships. Engine-powered vessels had larger nets, greater range, and better navigation. The capacity to catch fish became limitless. In addition, sonar technology gave an edge to detecting and catching fish. Sonar was originally developed during World War&nbsp;II to locate enemy submarines, but was later applied to locating schools of fish. These new technologies, as well as bottom trawlers that destroyed entire ecosystems, contributed to the collapse of Atlantic cod. They were vastly different from old techniques used, such as hand lines and long lines.{{citation needed|date=August 2022}}

The fishery has only recently begun to recover, and may never fully recover because of a possibly stable change in the [[food chain]]. Atlantic cod was a top-tier predator, along with [[haddock]], [[flounder]] and [[hake]], feeding upon smaller prey, such as [[herring]], [[capelin]], [[shrimp]], and [[snow crab]].<ref name="Frank">{{cite journal|author=Kenneth T. Frank |author2=Brian Petrie |author3=Jae S. Choi |author4=William C. Leggett|s2cid=45088691 |year=2005|title=Trophic Cascades in a Formerly Cod-Dominated Ecosystem|journal=[[Science (journal)|Science]] |volume=308 |pages=1621–1623 |doi=10.1126/science.1113075|pmid=15947186|issue=5728 |bibcode=2005Sci...308.1621F }}</ref> With the large predatory fish removed, their prey have had population explosions and have become the top predators, affecting the survival rates of cod eggs and fry.

In the winter of 2011–2012, the cod fishery succeeded in convincing [[NOAA]] to postpone for one year the planned 82% reduction in catch limits. Instead, the limit was reduced by 22%. The fishery brought in $15.8&nbsp;million in 2010, coming second behind Georges Bank haddock among the region's 20 regulated bottom-dwelling [[groundfish]]. Data released in 2011 indicated that even closing the fishery would not allow populations to rebound by 2014 to levels required under US federal law. Restrictions on cod effectively limit fishing on other groundfish species with which the cod swim, such as [[flounder]] and haddock.<ref name="Press">{{cite news |author=The Associated Press |title=Cod Fishermen's Alarm Outlasts Reprieve on Catch Limits |work=The New York Times |date=12 February 2012 |url=https://www.nytimes.com/2012/02/12/us/cod-fishermens-alarm-outlasts-reprieve-on-catch-limits.html}}</ref>

===Northeast Atlantic cod===
[[File:Atlantic cod landings eastern.jpg|thumb|418x418px|Reported landings of Atlantic cod (''Gadus morhua'') in the eastern Atlantic for each of the 16 populations/management units. Data source: ICES.]]
[[File:NEAcodBiomass.png|thumb|Estimated biomass of the Northeast Arctic cod stock for the period 1946–2012, in million tons: Light blue bars represent the immature fraction of the stock, while the darker blue bars represent the spawning biomass.<ref>Arctic Fisheries Working Group of [[International Council for the Exploration of the Sea|ICES]], published in the ICES Report AFWG CM 2013, ACOM:05. The estimation method was standard [[virtual population analysis]].</ref>]]

The Northeast Atlantic has the world's largest population of cod. By far, the largest part of this population is the Northeast Arctic cod, as it is labelled by the [[International Council for the Exploration of the Sea|ICES]], or the Arcto-Norwegian cod stock, also referred to as ''skrei'', a Norwegian name meaning something like "the wanderer", distinguishing it from coastal cod. The Northeast Arctic cod is found in the [[Barents Sea]] area. This stock spawns in March and April along the Norwegian coast, about 40% around the [[Lofoten]] [[archipelago]]. Newly hatched larvae drift northwards with the coastal current while feeding on larval [[copepod]]s. By summer, the young cod reach the Barents Sea, where they stay for the rest of their lives, until their spawning migration. As the cod grow, they feed on [[krill]] and other small crustaceans and fish. Adult cod primarily feed on fish such as [[capelin]] and [[Atlantic herring|herring]]. The northeast Arctic cod also show [[Cannibalism (zoology)|cannibalistic]] behaviour. Estimated stock size was {{cvt|2260000|t|ST}} in 2008.

The North Sea cod stock is primarily fished by [[European Union]] member states, the United Kingdom and Norway. In 1999, the catch was divided among Denmark (31%), Scotland (25%), the rest of the United Kingdom (12%), the Netherlands (10%), Belgium, Germany and Norway (17%). In the 1970s, the annual catch rose to between {{cvt|200000|and|300000|t|ST}}. Due to concerns about [[overfishing]], catch quotas were repeatedly reduced in the 1980s and 1990s. In 2003, ICES stated a high risk existed of stock collapse if then current exploitation levels continued, and recommended a moratorium on catching Atlantic cod in the North Sea during 2004. However, agriculture and fisheries ministers from the [[Council of the European Union]] endorsed the EU/Norway Agreement and set the total allowable catch <!-- (TAC) --> at {{cvt|27300|t|ST}}.<ref>{{cite web|url=http://portunusgroup.com/products/atlantic-cod/|title=Our Products: Atlantic Cod|work=portunusgroup.com|access-date=22 November 2013}}</ref> [[Sustainable seafood advisory lists and certification#Guides and advisory lists|Seafood sustainability guides]], such as the [[Monterey Bay Aquarium]]'s [[Seafood Watch]], often recommend environmentally conscious customers not purchase Atlantic cod.

The stock of Northeast Arctic cod was more than four million tons following [[World War II|World War&nbsp;II]], but declined to a historic minimum of {{cvt|740000|t|ST}} in 1983. The catch reached a historic maximum of {{cvt|1343000|t|ST}} in 1956, and bottomed out at {{cvt|212000|t|ST}} in 1990. Since 2000, the spawning stock has increased quite quickly, helped by low fishing pressure. The total catch in 2012 was {{cvt|754131|t|ST}}, the major fishers being Norway and Russia.<ref>{{cite web|url=http://standardgraphs.ices.dk/download/HandlerDownload.ashx?year=2013&EcoRegion=137491&Species=44515|archive-url=https://web.archive.org/web/20140325115725/http://standardgraphs.ices.dk/download/HandlerDownload.ashx?year=2013&EcoRegion=137491&Species=44515|title=ICES Stock Database Disclaimer|access-date=25 March 2014|archive-date=25 March 2014}}</ref>

=== Baltic cod ===
Decades of overfishing in combination with environmental problems, namely little water exchange, low salinity and oxygen-depletion at the sea bottom, caused major threats to the Baltic cod stocks.

There are at least two populations of cod in the [[Baltic Sea]]: One large population that spawns east of [[Bornholm]] and one population spawning west of Bornholm. Eastern Baltic cod is genetically distinct and adapted to the brackish environment. Adaptations include differences in hemoglobin type, osmoregulatory capacity, egg buoyancy, sperm swimming characteristics and spawning season. The adaptive responses to the environmental conditions in the Baltic Sea may contribute to an effective reproductive barrier, and thus, eastern Baltic cod can be viewed as an example of ongoing speciation.<ref>{{Cite journal|last1=Berg|first1=Paul R.|last2=Jentoft|first2=Sissel|last3=Star|first3=Bastiaan|last4=Ring|first4=Kristoffer H.|last5=Knutsen|first5=Halvor|last6=Lien|first6=Sigbjørn|last7=Jakobsen|first7=Kjetill S.|last8=André|first8=Carl|date=2015-05-20|title=Adaptation to Low Salinity Promotes Genomic Divergence in Atlantic Cod (Gadus morhua L.)|journal=Genome Biology and Evolution|volume=7|issue=6|pages=1644–1663|doi=10.1093/gbe/evv093|issn=1759-6653|pmc=4494048|pmid=25994933}}</ref> Due to drastically low cod population sizes, commercial fishing of eastern Baltic cod is prohibited since 2019. However, unfavourable environmental conditions in the eastern Baltic Sea, i.e., low salinity and increasing oxygen-depletion at the sea bottom, led to presently only the Bornholm Basin (Southern Baltic Sea) having sufficient conditions for successful reproduction of eastern Baltic cod.<ref>{{Cite journal|last1=MacKenzie|first1=BR|last2=Hinrichsen|first2=HH|last3=Plikshs|first3=M|last4=Wieland|first4=K|last5=Zezera|first5=AS|date=2000|title=Quantifying environmental heterogeneity:habitat size necessary for successful development of cod Gadus morhua eggs in the Baltic Sea|journal=Marine Ecology Progress Series|volume=193|pages=143–156|doi=10.3354/meps193143|bibcode=2000MEPS..193..143M |s2cid=3548719 |issn=0171-8630|doi-access=free}}</ref>

The western Baltic cod consists of one or several small subpopulations that are genetically more similar to the North Sea cod. In the Arkona basin (located off [[Cape Arkona]], [[Rügen]]), spawning and migrating cod from both the eastern and western stocks intermingle in proportions that vary seasonally.<ref>{{Cite journal|last1=Hemmer-Hansen|first1=Jakob|last2=Hüssy|first2=Karin|last3=Baktoft|first3=Henrik|last4=Huwer|first4=Bastian|last5=Bekkevold|first5=Dorte|last6=Haslob|first6=Holger|last7=Herrmann|first7=Jens-Peter|last8=Hinrichsen|first8=Hans-Harald|last9=Krumme|first9=Uwe|last10=Mosegaard|first10=Henrik|last11=Nielsen|first11=Einar Eg|date=2019|title=Genetic analyses reveal complex dynamics within a marine fish management area|journal=Evolutionary Applications|language=en|volume=12|issue=4|pages=830–844|doi=10.1111/eva.12760|issn=1752-4571|pmc=6439499|pmid=30976313|bibcode=2019EvApp..12..830H }}</ref> The immigration of eastern cod into the western Baltic management unit may mask a poor state of the populations in the western management unit.