11 Fish That Clean U.S. Waterways—And 7 Invasive Species That Make It Worse
Some fish are nature’s quiet janitors—working around the clock to keep our rivers and lakes cleaner. Others? They barge in, take over, and leave destruction in their wake. Across the U.S., certain fish help control algae, clear debris, and balance ecosystems without asking for anything in return. They don’t get headlines, but they’re doing the …










