Overfishing and El Niño Push the World’s Biggest Single-Species Fishery to a Critical Point | Oceana
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February 2, 2016

Overfishing and El Niño Push the World’s Biggest Single-Species Fishery to a Critical Point

A fishing vessel plies the waters off the coast of Peru.
Photo credit: Shutterstock


In Peru, the warm water and low food availability that accompany El Niño conditions are spelling big trouble for the anchovies that make up the largest fishery on Earth. As stocks of Peruvian anchovies struggle, government-imposed catch limits for 2015 and 2016 have failed to keep pace. While fishermen report low landings and high numbers of immature and pregnant fish, scientists fear for the long-term viability of what the United Nations calls “the most heavily exploited fish in world history.”   

Last October, fishermen and scientists argued that a total halt to the second anchoveta (Engraulis ringens) season would be necessary to protect fish stocks from the combined effects of El Niño and overfishing. Strong El Niño years, such as 2015-16 and 1997-98, can tip anchoveta populations into collapse unless fishing pressure is reduced, says Patricia Majluf, Oceana’s vice president for Peru. 

The warning signs were evident in the first anchoveta season of 2015, which ran from March through June in the north of Peru. There are usually two anchoveta fishing seasons in one year, with separate management and seasons for the southern anchoveta fishery. Though the government assured the public that catches would increase dramatically from 2014, fishermen hauled in low numbers of fish, and those that they did catch were small, skinny and sexually immature.

The Peruvian Marine Research Institute (IMARPE) conducted a routine survey of anchoveta populations in October and found that the northern stocks had sunk to a low of 3.38 million metric tons. Of this, only 2 million metric tons were reproductive-age fish, well below the 5 million metric tons required by law to open the fishery. The fishing industry, which used a different methodology, estimated that stocks hovered at a healthier 6.8 million metric tons.

Despite the discrepancy in these two numbers, the Ministry of Production allowed the opening of the northern anchoveta fishery’s second season on November 17. The ministry set a catch quota of 1.1 million metric tons — half of the 2 million metric tons taken during the first season.  

“The real stock assessment resulted in a volume [of anchoveta] that should not have allowed fishers,” says Majluf, referring to the estimate from IMARPE.

Sexually immature fish made up 50 percent of the second opening’s catch, with some commercial boats’ haul going as high as 90 percent. National fishing regulations mandate that juveniles make up no more than 10 percent — by numbers, not by volume — of allowable landings.

Plenty of fish, but no food

The prognosis for the anchoveta may be bleak, but there is hope: Able to double their numbers in just 15 months, anchoveta populations respond almost immediately to favorable ocean conditions provided fishermen don’t take juveniles or pregnant adults.

Each year, only two percent of the anchoveta catch actually goes to feed people directly. Public campaigns increased Peru’s direct human consumption of anchoveta from 35,000 metric tons in 2006 to 120,000 metric tons in 2012 — an improvement, but still only a fraction of the total catch.

The remaining 98 percent of the anchoveta catch is reduced to fishmeal and fish oil, which is then exported to feed fish and livestock from farmed salmon in Chile to pigs in the United States and China.

Worldwide, about one-sixth of all wild fish we catch goes to feed other animals, not humans. This is an inefficient use of protein, as energy is lost with every step up in the food chain. In some cases, carnivorous species, like salmon or tuna, often require several pounds of wild fish to produce one pound of farmed fish.

In a country where seafood has traditionally been plentiful and affordable, turning the industry’s haul into animal feed — known as reduction fishing — deprives Peru’s small-scale fishermen of income. It also cuts down on an important source of protein for the country’s poorest communities.

Each day, 11 million Peruvians go hungry, almost 40% of the total population. Children in Peru are particularly hard-hit. In highland areas and parts of the Peruvian Amazon, 80 percent, or more, of children under the age of five are chronically malnourished.

The anchoveta is a foundation of Peru’s economy and marine ecosystems. What happens to it ripples through the food web, from predatory fish and squid — commercially important species in their own right — to penguins, seals, seabirds, and whales.  Peru must safeguard its anchovy stocks, or it risks harming livelihoods, marine wildlife, and food security for the poorest communities.

Oceana works with fishermen, researchers, and government officials to better manage anchoveta in order to save the oceans and feed the world. Learn more here.