A new study from Kiel University, led by researcher Renato Salvatteci, has found fundamental changes in the ocean, including warming and oxygen depletion, may have significant effects on fish stocks, including the displacement of individual species and stocks, including Peru’s anchoveta fishery.
The findings were published in the journal “Science” on 7 January, 2022. Researchers at Kiel University, together with colleagues from Germany, Canada, the U.S., and France, were able to reconstruct environmental conditions of the Eemian interglacial warm period 125,000 years ago – when conditions were similar to those predicted for the end of the 21st century due to global warming, with water temperatures two degrees Celsius higher than today and increased oxygen deficiency in mid-depth water masses – by using sediment samples from the Humboldt Current system off the coast of Peru. They found that at warmer temperatures, mainly smaller, goby-like fish species became dominant and pushed back anchovy populations. Smaller fish can adapt better to warmer temperatures and in less-oxygenated waters thanks to their larger gill surface area relative to their body volume, the study stated.
“The conditions of this past warm period that we were able to reconstruct from our samples can definitely be compared to the current development and put in context with future scenarios,” Salvatteci said. “We conclude from our results that the effects of human-induced climate change may have a stronger influence on the evolution of stocks in the region than previously thought." The effects have possibly far-reaching impacts on Peru, local fisheries income, and global trade in anchovies, potentially affecting global food security, he said.
The ocean off of South America’s west coast of is one of the most vital and productive fishing grounds on earth, according to the university. Around 8 percent of the global catch of marine species comes from the areas off the coast of Peru, with the near-surface Humboldt Current providing a high nutrient supply for commercially developed fish such as anchovy.
“Despite a flexible, sustainable, and adaptive management strategy, anchovy biomass and landings have declined, suggesting that we are closer to the ecological tipping point than suspected,” Salvatteci said.
Photo courtesy of Sociedad Nacional de Pesquería
