On September 18, 15 larger young Atlantic sturgeon and several thousand smaller fish entered the Ina River at Goleniów, Poland, as hundreds of local people watched and took part. The smaller fish were about 15 centimetres long. The release marks the first of its kind on the Polish side of the Oder Delta, following earlier releases in Germany.
The event is part of a wider effort to bring the region’s rivers back to life. Rivers across the Oder Delta were straightened, deepened and embanked, while dams and weirs blocked the movement of fish. The Rewilding Oder Delta team and local partners on both sides of the Polish-German border are removing barriers, restoring spawning grounds, rewetting wetlands and improving riverside habitats. Their goal is to make waterways more natural and better able to support wildlife.
That work matters especially for migratory fish. They need to travel between freshwater rivers, the Stettin Lagoon and the Baltic Sea to reach feeding, nursery and spawning areas. Atlantic sturgeon once lived in the Baltic and its tributaries, but disappeared from the region during the twentieth century. Overfishing was a major cause; pollution, damaged spawning grounds and barriers to migration also contributed.
The sturgeon released at Goleniów were raised at the Polish Anglers Union’s fish farming and rearing centre there. Their larvae came from Germany, where the Berlin-based Leibniz Institute of Freshwater Ecology and Inland Fisheries and the State Research Institute for Agriculture and Fisheries Mecklenburg-Vorpommern oversaw reproduction and hatching. In Goleniów, the young fish ate natural food and grew in tanks supplied with water from the Wiśniówka, a tributary of the Ina. That helped them adjust to local conditions before entering the river.
The Ina was chosen because sturgeon historically lived there and years of restoration have made the river more suitable for their return. Barriers have been removed, habitats restored and water quality improved. “By protecting the sturgeon and its habitats, we are also protecting many other fish species,” says Dr Jan Krzystolik, an ichthyologist at the Leibniz Institute. He notes that opening rivers can help salmon, eels and other migratory fish as well.
Sturgeon are unusual fish with an ancient lineage. Five rows of hard, armour-like plates cover their bodies, and whisker-like feelers help them find food on the riverbed. They can live for many decades and grow to several metres long. Their return is a sign of progress, but it also reflects the conditions many kinds of river life need: clean, oxygen-rich water and places to spawn. More natural rivers can benefit people too, by helping provide clean water, easing the effects of floods and droughts, supporting fishing and recreation, and making landscapes more resilient to climate change.
The young fish now have a chance to grow in a river being gradually reconnected to its wider watershed. Their release does not finish the work, but it offers a clear measure of what restoration can make possible: a route back for a species that had vanished from the region, and healthier waterways for the wildlife and communities that depend on them.