The European Catfish: A Silent Invader in Spain's Waters

The European catfish, a massive freshwater fish from Eurasia, has quietly taken over parts of Spain. It first arrived in the Ebro River in 1974. People brought it there for fun fishing. But now, it's in seven big river systems. It's a problem because it's not from here. It spreads fast and takes over. At first, the catfish spread slowly. From the 1970s to the 1990s, it didn't go far. But then, from 2000 to 2009, it exploded. It took over six times more area in just nine years. After 2010, it slowed down. But in some places, like the Duero, Guadalquivir, and Andalusian Mediterranean basins, it's still spreading fast. Scientists used data from 1974 to 2024. They looked at where the catfish was first seen in each waterbody. They found that the catfish now covers 129 grid cells. Each cell is 10x10 kilometers. That's a lot of area! Experts used special models to predict the future. They think the catfish will keep spreading. But it won't spread as fast as before. Some areas, like the Ebro, are already full of catfish. So, the catfish might not take over more area by 2030. But there's a catch. The models aren't perfect. People might move catfish illegally. Climate change could also change where catfish can live. So, the future is uncertain. The catfish is a big problem. It's important to stop people from moving it. We need better ways to watch for it. And we need to follow the rules. Updating data and doing more research can help. It's the only way to control this invader.