How El Nino Affects Global Squid Production: Peru's Production Drops By 70%, Argentina Lags Behind, And The North Pacific Is Fragmented.

In September 2026, the Peruvian Multi-Sectoral El Niño Research Committee (ENFEN) raised its forecast for the probability of an "abnormal intensity" El Niño event along the coast (Niño 1+2 zone) between September and January of the following year to 85%, a 10 percentage point increase from 75% at the end of August. According to ENFEN's calculations, this probability was 82% in October, 78% in November, 70% in December, and then dropped to 59% in January of the following year. For short-life-cycle, annual cephalopods, El Niño is the single most important environmental variable for production fluctuations. However, the same warming event impacts different squid producing regions globally in different ways, directions, and time lags-Peruvian squid are hit hardest, Argentine squid experience delayed transmission, and different populations in the North Pacific diverge.

 

Peruvian Squid: Weakened Upwelling Leads to 70% Drop in Yield

Peruvian squid (Dosidicus gigas, locally known as "Pota") is directly impacted by El Niño. Its fishing grounds rely on upwelling along the Peruvian coast-upwellings that bring deep, nutrient-rich water to the surface, supporting plankton and thus the squid's food base. During El Niño, warm water intrusions suppress upwelling, reducing nutrient supply, shrinking squid habitats, and dispersing their distribution, resulting in a sharp decline in catches. A 2006 study by Claire Waluda and Paul Rodhouse of the British Antarctic Survey, published in the *Marine Ecology Progress Series*, showed a positive correlation between squid abundance in Peruvian fishing grounds and sea surface temperatures between 17 and 22°C. The significant weakening of upwelling during the super El Niño of 1997-1998 directly led to extremely low Peruvian squid catches.

 

Official data from the Peruvian Marine Research Institute (IMARPE) confirms this mechanism. During the 1997-1998 El Niño, Peruvian squid catches plummeted to less than 16,000 tons; while peak years between 1991 and 2019 saw catches exceeding 500,000 tons (2008 and 2014). The most recent round was equally dramatic: Peruvian squid catches reached 621,900 tons in 2023, then plummeted to 188,300 tons in 2024, a drop of about 70% in one year, one of the lowest levels in nearly a decade. Jesús Eloy Barrientos, Peru's Deputy Minister of Fisheries and Aquaculture, stated in early 2025 that the strong El Niño from February 2023 to March 2024 caused the population to disperse starting in the fall of 2023, altering the spatial availability of the resource and consequently impacting the fishing efficiency of Peruvian artisanal fishing fleets, primarily composed of small boats along the coast.

 

A sharp drop in production does not equate to resource collapse. A 2025 assessment report submitted to the 13th Scientific Committee of the South Pacific Fisheries Management Organization (SPRFMO) by the team of Li Gang and Chen Xinjun from Shanghai Ocean University, after incorporating squid fishing data from Peruvian, Chilean, and Chinese vessels into a Bayesian state-space model, concluded that even with a significant decline in catches in 2024, the Peruvian squid population remained healthy and did not suffer from overfishing. The 2024 decline was more a result of El Niño altering resource distribution and reducing availability, rather than a depletion of biomass itself. This report separately characterized the role of environmental factors in the "environmentally sensitive surplus production model," indicating that *Dosidicus gigas* is highly sensitive to climate-driven fluctuations in carrying capacity and intrinsic growth rate.

 

Argentine Squid: Not Directly Affected, but Relying on the Antarctic Circumpolar Wave for Delayed Transmission

The response pathway of the Argentine squid (Illex argentinus) differs from that of the Peruvian squid. It is not directly affected by El Niño in the Pacific Ocean, but the abnormal sea surface temperature in the Pacific propagates eastward around Antarctica along the Antarctic Circumpolar Wave, eventually manifesting in the Patagonian shelf of the southwestern Atlantic. A 1999 study by Claire Waluda and Paul Rodhouse et al., published in the *Marine Ecology Progress Series*, found that the impact of El Niño sea surface temperature anomalies in the Pacific Ocean on the southern fishing grounds (southern Patagonian shelf) of the Argentine squid lagged by about two years, and on the northern hatching grounds by about five years. This means that the Argentine squid's response to El Niño does not manifest in the same year, but rather is delayed by one to several fishing seasons before being reflected in replenishment levels.

 

Temperature also has a clear threshold for the individual development of this species. An analysis based on 20 years of fisheries and sea surface temperature time series and 520 regression studies (published in *Estuarine, Coastal and Shelf Science* in 2021) showed that when hatchery water temperatures were above 17.5°C, females in the Falkland Islands were smaller and less mature; when migratory water temperatures were above 13.5°C, larger females with a higher proportion of maturity appeared in the Falkland Islands, but overall abundance was lower. The relationship between temperature signals and individual size, maturity ratio, and abundance was used to predict the yield and size structure of the Argentine squid fishing season.

 

The 2015-2016 El Niño provides a clear example of this lag. According to the FAO's GLOBEFISH records, the Argentine squid catch in 2015 was approximately 126,500 tons, a decrease of about 25% compared to 2014. By the 2016 fishing season, the catch of Illex within the Falkland Islands' exclusive economic zone was only about 2,000 tons, compared to about 170,000 tons in the same period of the previous season, a drop of over 90%. A study published in *Marine Environmental Research* in 2025 by Zhang Lizi et al. from Shanghai Ocean University indicates that the "climate-catch" relationship for Argentine squid is not static, but rather exhibits two threshold years-1990/1991 and 2015/2016. In the latter threshold year, the Weddell sea ice extent and sea surface temperature synchronously switched to a new state, accompanied by abnormal fluctuations in sea level height, causing a sustained decline in Argentine squid catches. In other words, climate-driven environmental non-stationarity is an undeniable factor in the fluctuations in Argentine squid production, even after removing the influence of fishing intensity.

 

North Pacific: directional divergence; warming events do not always lead to reduced catches

The response of various squid populations in the North Pacific to El Niño is not uniform. The winter population of Japanese squid (Todarodes pacificus) is the most important biomass component. A 2018 study by Yu Wei et al. from Shanghai Ocean University, published in the English edition of *Acta Oceanologica Sinica*, found that moderate-intensity El Niño events may actually benefit Japanese squid: warming events shrink the spawning ground suitable area (SSA), but are accompanied by increased chlorophyll concentration, improved larval food, and increased replenishment and catch per unit catch effort (CPUE); moderate-intensity La Niña events lead to expanded spawning grounds and high chlorophyll, resulting in a significant increase in replenishment and CPUE. Under this mechanism, the abundance of Japanese squid is more influenced by the superimposed Pacific Decadal Oscillation (PDO), with a significant regime shift occurring around 1990/1991.

 

The California market squid (Loligo opalescens) presents a different picture. The California Marine Species Portal's "Market Squid Enhancement Status Report" cites multiple studies indicating significantly lower landing numbers in major fishing grounds in Southern California during El Niño years. Data from the National Oceanic and Atmospheric Administration (NOAA) Pacific Fisheries Environmental Group also records a significant decline in California squid landing numbers during four El Niño events: 1958, 1983-1984, 1992, and 1998-in warmer water years, squid leave their usual spawning grounds or dive to deeper, colder waters to spawn. However, the rising temperatures of California market squid spawning grounds have also been observed, accompanied by an expansion of their habitat to higher latitudes and northwards, indicating an overall northward shift in suitable spawning areas.

 

Migration to the polar regions is a common trend observed in North Pacific squid. A study published in the *ICES Journal of Marine Science* in 2023 by Wang Jintao et al. from Shanghai Ocean University used data from Chinese squid fishing vessel logs from 2005 to 2017 to construct a spatiotemporal model, comparing the North Pacific squid (Ommastrephes bartramii) and the Peruvian squid (Dosidicus gigas): the biomass peaks and troughs of the two species corresponded to La Niña and El Niño events, respectively, but the magnitudes were smaller than the impact of directional climate variability; the study also observed significant migration of low- and mid-latitude squid populations towards the polar regions.

 

Common Patterns: Short Life Cycles Amplify Fluctuations, Recurring Miniaturization

By examining the three production areas together, several patterns become clear. First, the annual, semelparous life cycle of cephalopods determines that the population responds extremely quickly and dramatically to environmental fluctuations-this is both the underlying reason for the "70% decline in Peruvian squid in one year" and the mechanism behind its rapid recovery within three to four years after several El Niño events throughout history. Second, the miniaturization and earlier sexual maturity associated with warming have repeatedly occurred in multiple production areas: In the Gulf of California, after the El Niño events of 1997-1998 and 2009-2010, Peruvian squid exhibited a phenotype where mature individuals plummeted from tens of kilograms to less than 0.1 kilograms; in the Gulf of California after 2009-2010, the miniaturized phenotype even solidified, described by researchers as a "tropical phenotype migrating to the polar regions." Third, the net effects of the same El Niño event on different production areas can be opposite, which is precisely the dividing line summarized in the three sentences at the beginning of this article: "Peru reduced, Argentina lagged, and the North Pacific diverged."

 

Returning to the present, ENFEN's probability curve shows that the probability of an El Niño anomaly along the coast reaches 85% in September 2026, then declines month by month, dropping to 59% in January 2027. The most likely scenario in February and March is between "strong" and "abnormal." The next round of changes in global squid production is unfolding in these different time lags and directions.

 

In September 2026, the Peruvian Multi-Sectoral El Niño Research Committee (ENFEN) raised its forecast for the probability of an "abnormal intensity" El Niño event along the coast (Niño 1+2 zone) between September and January of the following year to 85%, a 10 percentage point increase from 75% at the end of August. According to ENFEN's calculations, this probability was 82% in October, 78% in November, 70% in December, and then dropped to 59% in January of the following year. For short-life-cycle, annual cephalopods, El Niño is the single most important environmental variable for production fluctuations. However, the same warming event impacts different squid producing regions globally in different ways, directions, and time lags-Peruvian squid are hit hardest, Argentine squid experience delayed transmission, and different populations in the North Pacific diverge.

 

Peruvian Squid: Weakened Upwelling Leads to 70% Drop in Yield

Peruvian squid (Dosidicus gigas, locally known as "Pota") is directly impacted by El Niño. Its fishing grounds rely on upwelling along the Peruvian coast-upwellings that bring deep, nutrient-rich water to the surface, supporting plankton and thus the squid's food base. During El Niño, warm water intrusions suppress upwelling, reducing nutrient supply, shrinking squid habitats, and dispersing their distribution, resulting in a sharp decline in catches. A 2006 study by Claire Waluda and Paul Rodhouse of the British Antarctic Survey, published in the *Marine Ecology Progress Series*, showed a positive correlation between squid abundance in Peruvian fishing grounds and sea surface temperatures between 17 and 22°C. The significant weakening of upwelling during the super El Niño of 1997-1998 directly led to extremely low Peruvian squid catches.

 

Official data from the Peruvian Marine Research Institute (IMARPE) confirms this mechanism. During the 1997-1998 El Niño, Peruvian squid catches plummeted to less than 16,000 tons; while peak years between 1991 and 2019 saw catches exceeding 500,000 tons (2008 and 2014). The most recent round was equally dramatic: Peruvian squid catches reached 621,900 tons in 2023, then plummeted to 188,300 tons in 2024, a drop of about 70% in one year, one of the lowest levels in nearly a decade. Jesús Eloy Barrientos, Peru's Deputy Minister of Fisheries and Aquaculture, stated in early 2025 that the strong El Niño from February 2023 to March 2024 caused the population to disperse starting in the fall of 2023, altering the spatial availability of the resource and consequently impacting the fishing efficiency of Peruvian artisanal fishing fleets, primarily composed of small boats along the coast.

 

A sharp drop in production does not equate to resource collapse. A 2025 assessment report submitted to the 13th Scientific Committee of the South Pacific Fisheries Management Organization (SPRFMO) by the team of Li Gang and Chen Xinjun from Shanghai Ocean University, after incorporating squid fishing data from Peruvian, Chilean, and Chinese vessels into a Bayesian state-space model, concluded that even with a significant decline in catches in 2024, the Peruvian squid population remained healthy and did not suffer from overfishing. The 2024 decline was more a result of El Niño altering resource distribution and reducing availability, rather than a depletion of biomass itself. This report separately characterized the role of environmental factors in the "environmentally sensitive surplus production model," indicating that *Dosidicus gigas* is highly sensitive to climate-driven fluctuations in carrying capacity and intrinsic growth rate.

 

Argentine Squid: Not Directly Affected, but Relying on the Antarctic Circumpolar Wave for Delayed Transmission

The response pathway of the Argentine squid (Illex argentinus) differs from that of the Peruvian squid. It is not directly affected by El Niño in the Pacific Ocean, but the abnormal sea surface temperature in the Pacific propagates eastward around Antarctica along the Antarctic Circumpolar Wave, eventually manifesting in the Patagonian shelf of the southwestern Atlantic. A 1999 study by Claire Waluda and Paul Rodhouse et al., published in the *Marine Ecology Progress Series*, found that the impact of El Niño sea surface temperature anomalies in the Pacific Ocean on the southern fishing grounds (southern Patagonian shelf) of the Argentine squid lagged by about two years, and on the northern hatching grounds by about five years. This means that the Argentine squid's response to El Niño does not manifest in the same year, but rather is delayed by one to several fishing seasons before being reflected in replenishment levels.

 

Temperature also has a clear threshold for the individual development of this species. An analysis based on 20 years of fisheries and sea surface temperature time series and 520 regression studies (published in *Estuarine, Coastal and Shelf Science* in 2021) showed that when hatchery water temperatures were above 17.5°C, females in the Falkland Islands were smaller and less mature; when migratory water temperatures were above 13.5°C, larger females with a higher proportion of maturity appeared in the Falkland Islands, but overall abundance was lower. The relationship between temperature signals and individual size, maturity ratio, and abundance was used to predict the yield and size structure of the Argentine squid fishing season.

 

The 2015-2016 El Niño provides a clear example of this lag. According to the FAO's GLOBEFISH records, the Argentine squid catch in 2015 was approximately 126,500 tons, a decrease of about 25% compared to 2014. By the 2016 fishing season, the catch of Illex within the Falkland Islands' exclusive economic zone was only about 2,000 tons, compared to about 170,000 tons in the same period of the previous season, a drop of over 90%. A study published in *Marine Environmental Research* in 2025 by Zhang Lizi et al. from Shanghai Ocean University indicates that the "climate-catch" relationship for Argentine squid is not static, but rather exhibits two threshold years-1990/1991 and 2015/2016. In the latter threshold year, the Weddell sea ice extent and sea surface temperature synchronously switched to a new state, accompanied by abnormal fluctuations in sea level height, causing a sustained decline in Argentine squid catches. In other words, climate-driven environmental non-stationarity is an undeniable factor in the fluctuations in Argentine squid production, even after removing the influence of fishing intensity.

 

North Pacific: directional divergence; warming events do not always lead to reduced catches

The response of various squid populations in the North Pacific to El Niño is not uniform. The winter population of Japanese squid (Todarodes pacificus) is the most important biomass component. A 2018 study by Yu Wei et al. from Shanghai Ocean University, published in the English edition of *Acta Oceanologica Sinica*, found that moderate-intensity El Niño events may actually benefit Japanese squid: warming events shrink the spawning ground suitable area (SSA), but are accompanied by increased chlorophyll concentration, improved larval food, and increased replenishment and catch per unit catch effort (CPUE); moderate-intensity La Niña events lead to expanded spawning grounds and high chlorophyll, resulting in a significant increase in replenishment and CPUE. Under this mechanism, the abundance of Japanese squid is more influenced by the superimposed Pacific Decadal Oscillation (PDO), with a significant regime shift occurring around 1990/1991.

 

The California market squid (Loligo opalescens) presents a different picture. The California Marine Species Portal's "Market Squid Enhancement Status Report" cites multiple studies indicating significantly lower landing numbers in major fishing grounds in Southern California during El Niño years. Data from the National Oceanic and Atmospheric Administration (NOAA) Pacific Fisheries Environmental Group also records a significant decline in California squid landing numbers during four El Niño events: 1958, 1983-1984, 1992, and 1998-in warmer water years, squid leave their usual spawning grounds or dive to deeper, colder waters to spawn. However, the rising temperatures of California market squid spawning grounds have also been observed, accompanied by an expansion of their habitat to higher latitudes and northwards, indicating an overall northward shift in suitable spawning areas.

 

Migration to the polar regions is a common trend observed in North Pacific squid. A study published in the *ICES Journal of Marine Science* in 2023 by Wang Jintao et al. from Shanghai Ocean University used data from Chinese squid fishing vessel logs from 2005 to 2017 to construct a spatiotemporal model, comparing the North Pacific squid (Ommastrephes bartramii) and the Peruvian squid (Dosidicus gigas): the biomass peaks and troughs of the two species corresponded to La Niña and El Niño events, respectively, but the magnitudes were smaller than the impact of directional climate variability; the study also observed significant migration of low- and mid-latitude squid populations towards the polar regions.

 

Common Patterns: Short Life Cycles Amplify Fluctuations, Recurring Miniaturization

By examining the three production areas together, several patterns become clear. First, the annual, semelparous life cycle of cephalopods determines that the population responds extremely quickly and dramatically to environmental fluctuations-this is both the underlying reason for the "70% decline in Peruvian squid in one year" and the mechanism behind its rapid recovery within three to four years after several El Niño events throughout history. Second, the miniaturization and earlier sexual maturity associated with warming have repeatedly occurred in multiple production areas: In the Gulf of California, after the El Niño events of 1997-1998 and 2009-2010, Peruvian squid exhibited a phenotype where mature individuals plummeted from tens of kilograms to less than 0.1 kilograms; in the Gulf of California after 2009-2010, the miniaturized phenotype even solidified, described by researchers as a "tropical phenotype migrating to the polar regions." Third, the net effects of the same El Niño event on different production areas can be opposite, which is precisely the dividing line summarized in the three sentences at the beginning of this article: "Peru reduced, Argentina lagged, and the North Pacific diverged."

 

Returning to the present, ENFEN's probability curve shows that the probability of an El Niño anomaly along the coast reaches 85% in September 2026, then declines month by month, dropping to 59% in January 2027. The most likely scenario in February and March is between "strong" and "abnormal." The next round of changes in global squid production is unfolding in these different time lags and directions.