The conservation paradox of critically endangered fish species: Trading alien sturgeons versus native sturgeon reintroduction in the Rhine-Meuse river delta.

Sturgeons rank among the most endangered vertebrates in the world. Yet, the dwindling of wild sturgeon populations stands in stark contrast to their thriving status in aquaculture. Moreover, through the exotic pet trade, sturgeons are introduced outside their natural ranges where they may compete and hybridize with native species and transmit parasites and diseases.