​Some fish species have already established a stable, naturally reproducing population in Bílina. Following the ide, which is thriving in the river, other fish species are also on the rise. Unipetrol, in cooperation with the Czech Fishing Union, released bream and roach into the Bílina River on Wednesday. Both companies have worked together on restocking Bílina, which flows through the Ústí Region, since 2010.

"A control catch in summer showed that fish are thriving in the river. Ide, which are a specially protected species in the Czech Republic, have already established a naturally reproducing population. For this reason, we only released 500 ide as a supplementary species in autumn, the main species this year was bream. In total, we are releasing 3,000 bream into the river, which represents 300 kilos of fish," says Mikuláš Duda, Press Department Manager at Unipetrol. As well as ide and bream, the river will also be restocked with 350 roach. Unipetrol and the Czech Fishing Union have released several metric quintals of fish into the river.

Control catches show introduced fish are thriving
"On the recommendation of the Czech Fishing Union, we have carefully consider what fish species to choose, how old the fish are and only release them in places appropriate for that particular species. Two-year old ide, which are sufficiently resilient at that age, are released in Želenice. Bream, which prefer a quieter part of the river, are released near Hostomice and Lbín, where we also release roach,” explains Mikuláš Duda why fish are thriving. The success of the restocking programme is carefully checked with control catches. The most recent in summer of 2014 showed that fish are spawning naturally.

"That’s great news because it means water purity in the river has improved so much that life is beginning to renew itself, without the help of Man," said Vaclav Jelinek, Fisheries Technician of the North Bohemian Regional Association of the Czech Fishing Union. According to Jelinek, it was possible to choose species that are suited to the nature of Bílina and, in time, the spectrum of fish that originally lived in the river will be even more varied.

With the second phase, which began in 2013, Unipetrol has successfully built on the first part of the project, which was realised in 2010-2012. Unipetrol has invested over CZK 350,000 in restocking the river with tens of thousands of fish; the most recent release (about 300 kg of fish) took place in November 2014.