Human activities and the introduction of non-native fish species have placed significant pressure on native species in the Sava River, disrupting the natural ecosystem. As part of the SWIM initiative, a 38-kilometre section of the Sava River is being analyses to identify key habitats for migratory fish species, including the sterlet (lat. Acipenser ruthenus). These identified locations will serve as collection points for spawning material, which will be transferred to an ex-situ aquaculture conservation facility in Jagodno. There, juveniles with a genetic profile native to the river will be produced.

Once the first phase is completed, the juveniles will be relocated to the Virovitica fishponds, where they will adapt to more natural conditions and increase their likelihood of survival upon release. In the final stage, individuals demonstrating the highest health and viability will be released into the Noskovačka bara side arm, from which they are expected to migrate toward the Drava River. 

This initiative delivers a powerful boost to the conservation of migratory fish species. By identifying critical habitats, assessing their ecological value, preserving native genetic diversity, and producing native juveniles for supportive stocking, SWIM is creating concrete, science-riven solutions that help rebuild resilient wild fish populations and restore the ecological integrity of the Sava River.