- The asprete, a rare freshwater fish found in Romania, was once considered extinct after dam construction destroyed much of its habitat.
- The fish’s existence was confirmed by surveys conducted in the last 50 years but only a few were thought to survive in Romania’s Vâlsan River.
- However, a 2022 survey expedition found 58 specimens across a 15-kilometer stretch of the river.
The asprete, a ray-finned freshwater fish species that lives only in Romania, has long captured Mircea Marginean’s imagination. Experts say conservation efforts, as well as more robust survey attempts, led to the higher population count.
A Living Fossil
First discovered in 1956, the asprete (Romanichthys valsanicola) occupies a genus of its own and has no close relatives. Some experts also believe the asprete has lived on Earth for up to 65 million years, earning the fish a reputation as a “living fossil.” The fish is a nocturnal species that lives on the river bottom, usually under rocks, making it hard to detect.
In the 1960s, Romania built several hydroelectric dams upstream from known asprete habitats in the Argeș, Vâlsan and Doamnei rivers. Marginean says the building of dams resulted in the removal of sand and stones from the riverbed and the drying up of water.
But between the 1970s and early 2000s, fishers and scientists found the fish in the Vâlsan River — but only a handful at a time. In 2020, the Romanian ministry of the environment, water and forests estimated that there were 7 to 10 individuals left in the Vâlsan, leading some to refer to the asprete as “Europe’s rarest fish.”
In the early 2000s, conservationists working with an EU-funded LIFE Programme project helped reinstate some of the river flow of the Vâlsan River. Then in 2019, the Alex Găvan Foundation launched a project to further revitalize the river to protect the asprete, which is listed as a critically endangered species by the International Union for Conservation of Nature.
Ovidiu Stan, co-manager of the Alex Găvan Foundation, says there are currently four barriers in the Vâlsan River that cut the rivers into fragments. “We have started the first studies to find the best ways to remove these barriers or if necessary…”
Marginean says conservation efforts likely helped the asprete begin to recover. However, he says he also believes there previously weren’t enough surveys done on the species to fully understand its abundance and distribution. Based on the most recent survey that found 58 individuals, Marginean says he believes there are likely 300 to 350 individuals in the Vâlsan River.
Did you subscribe to our newsletter?
It’s free! Click here to subscribe!