While considerable resources are invested in seasonal forecasts and early-warning systems for food security, not enough is known about El Niño’s impact on the fisheries and aquaculture sectors, even though its name was given in the 1600s by fishers off the coast of Peru.
To remedy that, FAO is publishing, in partnership with French National Research Institute for Sustainable Development (IRD France), the report El Niño Southern Oscillation (ENSO) effects on fisheries and aquaculture. This report captures the current state of knowledge on the impacts of ENSO events across sectors, from food security to safety at sea, from fish biology and fishing operation to management measures.
El Niño is widely known as a climate pattern that begins over the Pacific Ocean but wreaks havoc on ecosystems in land and water far away from its origin. Its consequences include droughts and major harvest shortfalls in large swatches of Africa and Indonesia, forest fires in Australia, and serious flooding in South America.
ENSOs are often simplified to reflect two main phases: El Niño, an anomalous warming phase in the central and/or eastern equatorial Pacific Ocean, and an opposite cooling phase called La Niña.
In the former phase, a thickened surface layer of warm water prevents cold and nutrient-rich deep ocean water to reach the surface layer where photosynthesis occcurs, putting a break on ocean production. This lowers the availability of food to local fish species such as anchoveta, which in turn either migrate southwards or suffer a productivity collapse.
While understanding of ENSOs has developed greatly since the 1950s, researchers have also been stymied as its incidences are rarely similar. Adding to the complexity is that the frequency and intensity of these events appear to have intensified in the past two decades, with some climate models suggesting these trends may continue as the climate changes.
“ENSO is not just a binary phenomenon (either warm or cold). Every ENSO event is different in signal, intensity, duration, and so are their consequences,” says Arnaud Bertrand, marine ecologist at IRD, who coordinated the report. “Understanding the diversity is key to developing predictive and preparatory capacities.
Read and download the report: El Niño Southern Oscillation (ENSO) effects on fisheries and aquaculture.
Original source: FAO
Published on 22 April 2020
