Fish and Pollution: How European Chub Fight Back

In Italy's Veneto Region, PFAS pollution has become a significant issue, affecting both the environment and wildlife. These tough-to-break-down chemicals build up in animals over time, making them a major concern. Freshwater fish, like the European chub, are particularly vulnerable. Researchers wanted to see how these fish cope with long-term PFAS exposure. They looked at three different PFAS levels in the water: low, medium, and high. The fish's kidneys were studied because they are a major site for these pollutants to accumulate. The study found that the fish's bodies respond to PFAS by boosting their antioxidant defenses. These defenses help the fish deal with oxidative stress, which is like a chemical imbalance that can harm their cells. The fish produce special enzymes to fight this stress. One enzyme, catalase, works in tiny cell structures called peroxisomes. Another group of enzymes, selenium-dependent glutathione peroxidases, works in the cell's main area, the cytoplasm. Interestingly, the fish's bodies respond differently depending on the PFAS level. At low pollution levels, the fish produce more catalase. At high pollution levels, they produce more selenium-dependent glutathione peroxidases. This shows that the fish can adjust their defenses based on the threat level. The study also found that one particular gene, gpx1, is very active at high PFAS levels. This gene helps produce the selenium-dependent glutathione peroxidases. Another gene, gpx4, is more active at low PFAS levels, but it doesn't always lead to more protein production. This might be because the fish's bodies temporarily silence this gene's activity. This research shows that European chub can adapt to PFAS pollution, but it also highlights the need to understand how these pollutants affect wildlife. It's a reminder that even small changes in the environment can have big impacts on living creatures.