When the first paiche appeared in northern Bolivia 30 years ago, no one knew what to make of the red-scaled, carnivorous giants. Were they monsters? Did they eat human flesh? Were they the product of some nefarious science experiment? In fact, the invaders were among the oldest and largest freshwater fish on earth and, though threatened by overfishing in their natural habitats in Brazil and Peru, within decades they would expand their range through northern Bolivia's Amazon basin, transforming local economies and upending a fragile ecosystem.
Today, the paiche represents as much as 85 percent of all fish extracted in the river port of Riberalta, the most important fishery in this vast, landlocked nation. As the paiche expands its range into protected areas, it colonizes the breeding grounds of native species and consumes their young. Growing demand for fish also means more families—especially indigenous families—turn to fishing for their livelihoods, an economic boon that also puts increased pressure on the same native species being driven toward scarcity by the paiche. Nevertheless, paiche officially remains a threatened species, which means exporting wild-caught specimens from Bolivia is illegal.
For years, this combination of weak fishing laws and inadequate international understanding of a complex conservation problem has exacerbated an environmental calamity. As Bolivia finally passes laws to control the animal's population, the question is whether balance can still be struck between a rapidly changing environment and the economic need of the people who call it home.