Overfishing is wiping out large-bodied fish in the Amazon

It’s well known to most that the iconic Amazon rainforest is dwindling; with trees under the saw and flame as you read this. Thousands of acres of forest are destroyed each year. We all know this story. 

What is less common knowledge is the destruction of life in the Amazon River itself. Now a new study published in the Proceedings of the Royal Society B takes a hard look at fishing in the great river. This is the first, large-scale pan-Amazonian investigation of the river’s fisheries, and the findings aren’t good.

The research team looked at the places where fish catches are left to see what fish are present and which ones are becoming less common.        

“We are seeing a decline in large-bodied species,” said lead author Sebastian Heilpern, a Cornell Presidential Postdoctoral Fellow. “Large-body species are more vulnerable, as they are slower to develop. As they decline, we see they are also being replaced by smaller species. This pattern is consistent with overexploitation.”

The evidence is clear that fishes are being caught at rates which are unsustainable. There are simply not enough fish reproducing fast enough to replenish the numbers lost to hungry humans. Given that the Amazon is the most productive freshwater fishery in the world, it’s not surprising that the people living on its banks and the surrounding areas eat a lot of fish. In fact, at an average of 110 lbs of fish per year, per person, these are some of the highest fish consumption rates anywhere. 

This problem is a long time coming. In 1990, the United Nations reported that 90 percent of the fish were still at sustainable levels. By 2017, this percentage had dropped to an estimated 65.8 percent.  

There is still hope, however. The research suggests that greater enforcement of fishing regulations, improved monitoring and better laws could help the problem. “Additionally, expanding protected areas can maintain habitats that are critical for many fish species,” said Heilpern.

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By Zach Fitzner, Earth.com Staff Writer