WWF Bulgaria sends alert for start of winter migration of Sterlet


WWF Bulgaria, one of the project partners in the “LIFE for Danube Sturgeons”, used its social media channels to notify fishermen and the general public for the start of the winter migration of the native Danube Sterlet.

Earlier this year, during a planned monitoring expedition, a team of WWF Bulgaria registered 100 young Sterlet, found close to the village of Vetren, on the Bulgarian part of the Danube river. During the monitoring expedition, the team tagged and measured the young Sterlet, took genetic samples and released the juveniles back into the river. A few months later, at the beginning of autumn, the Sterlets began swimming back to their winter grounds, which makes the species vulnerable and easy to catch.

Sterlet (Acipenser ruthenus) is the smallest species of the Danube sturgeons and resides for its whole lifecycle in freshwater without migrating to the Black Sea. This species is largely sedentary, undertaking only short spawning migrations. Tagging has revealed a maximum migration distance in the Danube of just over 300 km. Nowadays Sterlet is the most widely distributed sturgeon in the Danube River basin, but still listed as vulnerable species.

WWF reminds the public that fishing Starlet in Bulgaria is illegal and if any Sterlet becomes an accidental bycatch, the fish should be released back into the water. Citizens are invited to contact the Executive Agency for Fisheries and Aquaculture if they witness or acquire information for fishing or trade in wild Sterlet. In Bulgaria in place is a fishing ban for any of the six wild Danube sturgeons until 2021.

Conservation of freshwater populations became a serious worldwide problem. The latest WWF’s report “Living Planet 2018” shows that globally the populations of freshwater fish have declined by 83% since 1970. The WWF’s “Living Planet” report is published every two years and presents an up-to-date picture of the human impact on nature.