Editing Humboldt Current (section)

== Influence of El Niño ==
[[File:Sitting at the Top of a Cloud.jpg|thumb|upright=1.3|[[La Silla Observatory|La Silla]] observatory is in the Southern outskirts of the [[Atacama Desert]], one of the driest places on Earth, it may come as a surprise to see cloud formations result of the Humboldt Current.<ref>{{cite web|title=Sitting at the Top of a Cloud|url=http://www.eso.org/public/images/potw1449a/|website=www.eso.org|publisher=European Southern Observatory|access-date=8 December 2014}}</ref>]]

The productivity of the Humboldt Current System is strongly affected by [[El Niño]] and [[La Niña]] events.<ref name=":0" />  During an El Niño event, the [[thermocline]] and upper region of the [[Oxygen minimum zone|OMZ]] deepen to greater than 600 m. This causes a loss of nitrogen and decrease in export of carbon. El Niño also causes poleward currents to increase in velocity. During non-El Niño years, productivity is very high due to the high nutrient contents, nitrogen recycling through processes such as denitrification, increased carbon export, and remineralization.<ref name=":0" />

During El Niño events, fish abundance and distribution are significantly affected, often leading to stock crashes and cascading social and economic impacts. These events have led to sequential changes, where sardines and anchovies have replaced each other periodically as the dominant species in the ecosystem. These species changes can have negative consequences for the fishing industry and the economies of the countries that fish the system. The anchoveta fishery in Peru was booming during the 1960s.<ref name=":1" /> In 1970, catches were reported to exceed 12 million tons per year. This accounted for 20% of the world's catches. An El Niño event occurred during 1972 and caused the anchoveta population to collapse. However, sardine populations saw a dramatic increase in the next 15–20 years. Consequently, sardine fisheries grew in this "[[regime shift]]".<ref name=":1" />