Lionfish are one of the most pernicious invasive species swimming in today’s oceans. And now, they’ve made it as far south as Brazil on their continuing and destructive territorial expansion.

Lionfish have been migrating south for years. They were first caught in the Gulf of Mexico, likely released from the aquarium trade, in 1985, and quickly expanded into U.S. East Coast and the Caribbean. They reached South American coastlines around 2010.

But the species stalled around Venezuela and Trinidad and Tobago. For 10 years, freshwater flowing from the Amazon River into the Atlantic and a confluence of currents acted as geographic barriers, stopping the fish from continuing south. But around 2020, at a time when few scientists were watching due to the