Massive 400-Pound Fish May be Heading toward Extinction in the Amazon

A massive fish may have become extinct in some areas of the Amazon Basin. Scientists have found that the arapaima fish, which once dominated Amazon fisheries, is slowly being harvested to extinction.

The arapaima is a fish that can reach up to 10 feet and can weight more than 400 pounds. It spawns on the edges of floodplain forests and comes to the surface to breathe every five to fifteen minutes. While this makes the fish easy to catch, it also makes it vulnerable to overexploitation.

The fish dominated fisheries in the Amazon nearly a century ago. Yet three of the five known species of arapaima have not been seen for decades. In order to assess the state of arapaima in this region, the scientists interviewed 182 fishers in 81 communities who were selected by their peers as being experts. In addition, the researchers used fish counts in 41 of the fishing communities, accounting for 650 square miles of floodplain area.

"Bioeconomic thinking has predicted that scarcity would drive up fishing costs, which would increase price and help save depleted species," said Leandro Castello, study leader, in a news release. "If that prediction were true, extinctions induced by fishing would not exist, but that is not what has happened."

In fact, the researchers found that arapaima populations are extinct in 19 percent of communities, depleted in 57 percent and overexploited in 17 percent.

"Because tropical regions suffer from widespread illegal fishing and a lack of data, these findings suggest that many similar fishing-induced extinctions likely are going unnoticed," said Castello. "There is also a lack of economic alternatives for the fishers."

The findings reveal the importance of regulating fishing in areas where arapaima are slowly being driven to extinction. In fact, Amazonas State, Brazil, shows that things can be different if these fish are properly managed.

"Many previously overexploited arapaima populations are now booming due to good management," said Castello. "The time has come to apply fishers' ecological knowledge to assess populations, document practices and trends, and solve fisheries problems through user participation in management and conservation."

The findings are published in the journal Aquatic Conservation: Marine and Freshwater Ecosystems.