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The Chilean jack mackerel ( Trachurus murphyi), sometimes called the jurel, Inca scad or Peruvian jack mackerel, is a species of jack mackerel in the genus Trachurus of the family Carangidae. Since the 1970s, it has become one of the world's more important commercial fish species. High volumes have been harvested, but the fishery may now be in danger of collapsing.
Not enough data are available to know for sure the Chilean jack mackerel Fish stocks. However, four separate stocks have been proposed: "a Chilean stock which is a straddling stock with respect to the high seas; a Peruvian stock which is also a straddling stock with the high seas; a central Pacific stock which exists solely in the high seas; and, a southwest Pacific stock which straddles the high seas and both the New Zealand and Australian ."
The Chilean jack mackerel has been recognised as a sister species of the Pacific jack mackerel, Trachurus symmetricus, since 2004.Poulin E, Cárdenas L, Hernández CE, Kornfield I and Ojeda FP (2004) "Resolution of the taxonomic status of Chilean and Californian jack mackerels using mitochondrial DNA sequence Journal of Fish Biology, 65 (4): 1160–1164.
In the early 1970s, Chilean jack mackerels started flourishing along the west coast of South America, and became important as a commercial species. The mackerel then expanded in a westward movement out into and across the open ocean, eventually reaching the coastal waters around New Zealand and Australia. During 1997 and 1998, a precipitous decline occurred in the catch (see the graph on the right), which can be attributed to changes in the sea surface temperature that accompanied the 1997–98 El Niño.Arcos DF, Cubillos LA and Núñez SP (2001) "The jack mackerel fishery and El Niño 1997–98 effects off Chile" Progress In Oceanography, 49 (1–4): 597–617.
On the eastern side of the south Pacific, the Chilean fishery operating mainly within its own EEZ has taken 75% of the global catch over the years. The Peruvian fishery captured 800,000 tonnes in 2001, but overall is an order of magnitude smaller. On the western side of the south Pacific, New Zealand fishes jack mackerel mainly inside their own EEZ, peaking modestly at 25,000 tonnes in 1995–96. From 1978 to 1991, the USSR fishing fleet intensively fished the jack mackerel belt on the high seas, taking 13 million tonnes. In subsequent years, other distant fishing nations, such as Belize, China, the Netherlands, and the Republic of Korea, have joined Russia fishing the jack mackerel belt, and by 2007, these nations were taking 18% of the global catch.
There are fears the fishery may collapse due to overfishing. Preventing the collapse of one of the world's largest fisheries Digital Journal, 14 February 2012. From 2006 to 2011, the biomass of the stocks declined another 63%. Fisheries scientists provisionally estimated in 2011 that to achieve the maximum sustainable yield a spawning biomass of about 7.4 million tons was required with a Fish mortality rate of 0.15. Report of the Jack Mackerel Subgroup South Pacific Regional Management Organisation, Annex SWG-10-03, Report of the Science Working Group, 19–23 September 2011. If the spawning stock is to rebuild, current catches should probably be less than 390,000 tons.
New data and indicators on the status of the jack mackerel stock suggest that conditions evaluated in detail from the last benchmark assessment (2022) are relatively unchanged. The population trend is estimated to be increasing. The indications of stock improvement (higher abundance observed in the acoustic survey in the northern part of Chile, better catch rates apparent in all fisheries for which data are available, and increase in average age in the Chilean fisheries) drive the increase. Near term spawning biomass is expected to increase from the 2018 estimate of 4.8 million t to 5.6 million t in 2019 (with approximate 90% confidence bounds of 4.5 – 7.0 million t)
In Chile, a small number of wealthy families own 87% of the jack mackerel harvest. With government agreement, they have been allocated quotas which scientists say are not sustainable. Lords of the fish iWatch News, 25 January 2012. In 2012, a heated dispute developed between Peru and Chile over the fishing of the mackerel. In mackerel's plunder, hints of epic fish collapse The New York Times, 25 January 2012. Peru and Chile in heated dispute over Jack Mackerel overfishing Digital Journal, 8 February 2012. Attempts have been made since 2006 to empower the South Pacific Regional Management Organisation so it can effectively regulate the jack mackerel industry on the high seas and across national boundaries. Geopolitical rivalries and lack of international cooperation is preventing this. In an interview with the International Consortium of Investigative Journalists, the French marine biologist Daniel Pauly compared jack mackerels to American bison, whose populations also collapsed in the 19th century from overhunting: "This is the last of the buffaloes. When they're gone, everything will be gone ... This is the closing of the frontier." Jack mackerel, down 90 percent in 20 years in once-rich southern seas, foretells wider global calamity; world's largest trawlers compete for what is left iWatch News, 25 January 2012.
As a way to protect the migrating mackerel, in 2013 the countries Chile, Peru, New Zealand and Australia, as well as six more agreed to form the "South Pacific Regional Fishing Management Organisation (RFMO)". The act has led to significant improvements; in 2019 the species had already recovered to a degree similar to the population in the 1990s.
All three species are found schooling around the coast of New Zealand. They are mainly captured using purse seine nets, and are managed as though they were one species or stock. Jack Mackerel NZ Forest and Bird. Retrieved 13 March 2012.
In its statistical returns, the FAO still treats the Pacific jack mackerel as though it were a subspecies. Trachurus murphyi (Nichols, 1920) FAO, Species Fact Sheet. Retrieved 2 March 2012. The capture graph in the fisheries section above is based on the figures supplied by the FAO for the capture of Chilean jack mackerel, and presumably includes also the capture amounts for Pacific jack mackerel.
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