The monitoring of the LIFE-Sterlet project located on the Upper Danube in Austria reported the first three mature sterlet males in 2021, originating from the stocking program. The fish were of the first batch incubated and reared within Danube water in the project’s container hatchery in 2017 and had a total length of 590-630 mm. With successive released of more than 230.000 fish in the following year it will be interesting to see further mature animals being recorded.
