Editing Porbeagle (section)

===Commercial fishing===
[[File:Lamna nasus hooked2.jpg|thumb|right|alt=Shark breaking the water surface next to a ship, with a fishing line coming from its mouth|A porbeagle is hooked on a longline; this shark is valued by both commercial and recreational fishers.]]
Prized for its [[shark meat|meat]] and fins, the porbeagle has long been under heavy fishing pressure.<ref name="iucn status 12 November 2021" /> The meat is sold fresh, frozen, or dried and salted, and ranks among the most valuable of any shark: in 1997 and 1998, it had a wholesale price of 5–7 eur/kg, four times that of the [[blue shark]] (''Prionace glauca''). Most of the demand comes from Europe, though the United States and Japan also import this species. The fins are shipped to [[East Asia]] for use in [[shark fin soup]]. The remainder of the shark may also be used for production of [[leather]], [[shark liver oil|liver oil]], and [[fishmeal]]. International trade in the porbeagle appears to be significant, but remains unquantified, as shark products tend not to be reported to the species level, and many consist of a mix of various species.<ref name="ssn"/><ref name="fowler et al"/> This shark is caught most readily on [[longline fishing|longlines]], but is also susceptible to [[gillnet]]s, [[driftnet]]s, [[trawl]]s, and handlines. It is valuable enough to be generally retained when caught as [[bycatch]]; if storage space cannot be spared, it may be [[shark finning|finned]] and the carcass discarded.<ref name="iucn status 12 November 2021" />

Intensive fishing for the porbeagle dates back the 1930s, when [[Norway]] and to a lesser extent [[Denmark]] began operating longline vessels in the Northeast Atlantic. The Norwegian annual catch rose from 279 tons in 1926 to 3,884 tons in 1933, and peaked at around 6,000 tons in 1947, with the resumption of fishing after [[World War II]]. Soon after, the stock collapsed; Norwegian annual catches declined steadily to 1,200–1,900 tons from 1953 to 1960, 160–300 tons in the early 1970s, and 10–40 tons in the late 1980s to early 1990s. Similarly, Danish annual catches fell from 1,500 tons in the early 1950s to under 100 tons in the 1990s.<ref name="compagno"/><ref name="iucnneatlantic"/> France and Spain began to target porbeagles in the Northeast Atlantic in the 1970s. French fishers operate mainly in the Celtic Sea and the [[Bay of Biscay]], and saw a decline from an annual catch over 1,000 tons in 1979 to 300–400 tons in the late 1990s. Catches by Spanish fishers were highly variable, ranging from negligible to over 4,000 tons per year, which may reflect shifts of fishing effort into historically less-exploited waters.<ref name="iucn status 12 November 2021" /> Since 2011, all fishing for the porbeagle has been illegal in waters of the [[European Union]], and EU-registered vessels are also prohibited from fishing for the species in [[international water]]s.<ref name=EU2011>{{Cite web|url = http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32011R0057|title = Council Regulation (EU) No 57/2011 of 18 January 2011 fixing for 2011 the fishing opportunities for certain fish stocks and groups of fish stocks, applicable in EU waters and, for EU vessels, in certain non-EU waters|date = 27 January 2011|website = EUR-Lex: Access to European Union law|publisher = [[Publications Office of the European Union]]}}</ref> In 2012, similar restriction came into effect in Norway.<ref name=NorwayRedList>{{Cite web|url=http://artsdatabanken.no/Rodliste2015/rodliste2015/Norge/42484|title=Lamna nasus (Bonnaterre, 1788)|publisher=Norsk rødliste for arter|access-date=5 July 2017|archive-date=22 May 2018|archive-url=https://web.archive.org/web/20180522112225/https://artsdatabanken.no/Rodliste2015/rodliste2015/Norge/42484|url-status=dead}}</ref>

As porbeagles had become scarce in the Northeast Atlantic, in the 1960s, the Norwegian fishing fleet moved west to the waters off New England and Newfoundland. A few years later, they were joined by longline vessels from the [[Faroe Islands]]. Norwegian annual catches rose from 1,900 tons in 1961 to over 9,000 tons in 1965;<ref name="campana et al"/> the catch was largely exported to [[Italy]], where porbeagle (''smeriglio'') is an extremely popular food fish.<ref name="martin"/><ref name="iucnnwatlantic"/> Again, the stock collapsed, this time in only six years; by 1970, Norwegian catches had fallen under 1,000 tons per year, and Faroese catches observed a similar trend. With the population decimated, most fishers moved on or switched to other species. Porbeagle numbers gradually recovered in the ensuing 25 years, to about 30% of pre-exploitation levels. In 1995, [[Canada]] established an [[Exclusive Economic Zone]] and became the primary fisher of porbeagles in the region. Between 1994 and 1998, Canadian fishing vessels landed 1,000–2,000 tons per year, which depleted the population to 11–17% of pre-exploitation levels by 2000.<ref name="campana et al"/> Strict regulations and greatly reduced fishing quotas introduced in 2000 have since begun to reverse the stock decline, though recovery of the stock is projected to take decades due to the low productivity of the species.<ref name="gibson and campana"/> Some evidence shows that incidental [[artificial selection]] caused by heavy fishing has led to a [[compensatory growth]] response, i.e. faster growth and earlier maturation.<ref name="cassoff et al"/>

In the Southern Hemisphere, commercial fishing for the porbeagle is mostly undocumented. Substantial numbers are caught incidentally by pelagic longline fisheries targeting more valuable species such as [[southern bluefin tuna]] (''Thunnus maccoyii''), [[swordfish]] (''Xiphias gladius''), and [[Patagonian toothfish]] (''Dissostichus eleginoides''), including vessels operated by [[Japan]], [[Uruguay]], [[Argentina]], [[South Africa]], and [[New Zealand]]. Porbeagle catches by the Uruguayan tuna pelagic longline fishery peaked in 1984 with 150 tons landed. Records of [[catch per unit effort]]  for this fishery have shown a 90% decline in porbeagle landings from 1988 to 1998, though whether this reflects a real population decline or changing fishing habits is uncertain. New Zealand has reported annual catches of 150–300 tons, mostly of immature individuals, from 1998 to 2003.<ref name="iucn status 12 November 2021" />