Freshwater Fish Secrets Unveiled by DNA Scanning Across Turkey

Scientists used a modern DNA trick called eDNA metabarcoding to map fish life in Turkey’s rivers. Instead of catching every fish, they filtered water from 29 spots spread over seven big river basins. The DNA that sloshes through the water was amplified and read by a high‑throughput machine, producing over 350, 000 clean sequences. From these data the team identified 52 fish species, some native, some invasive and a handful that had never been reported in those waters before. The survey covered more than 6, 000 kilometres of river, giving a country‑wide picture that had been missing. The Eastern Mediterranean basin stood out with the most species—28 in total—and the richest variety of fish. When scientists compared how similar or different the basins were, they found distinct patterns: some rivers shared many species while others were almost entirely separate. A statistical plot called PCoA made this clear, showing a clean split between the biogeographic zones.What makes eDNA powerful is that it can pick up fish that are rare or hidden. Traditional netting often misses these “cryptic” species, but the DNA method caught them all. This means that conservation plans based on eDNA can be more accurate and inclusive. Overall, the study offers a fresh baseline for Turkey’s freshwater fish. By showing how DNA scanning can reveal hidden diversity and geographic patterns, it encourages managers to use this tool for monitoring changes in river ecosystems—especially as climate shifts and human activities threaten fish habitats.