The history of the Atlantic sturgeon, Acipenser oxyrinchus Mitchill, 1815, in the Warta River of Central and Western Poland in the nineteenth century based on Polish sources
An analysis of Polish historical sources indicates that there are no references to sturgeon in the Warta River basin before 1810. It is hypothesized that there was no autochthonic sturgeon population in this river in historic times. The occasional occurrence of fish in the Warta River stemmed from their straying from the Oder River, especially during high waters. The situation changed in the second half of the nineteenth century because increasing pollution in the Oder River meant increasing numbers of fish entered the Warta River. Peak catches by fishers in Poznañ were in the 1880s and early 1890s, after which the population collapsed and never recovered. Overfishing in this period stemmed primarily from the effects of regulating the Warta River for navigation. The data presented herein might have implications for the current sturgeon reintroduction program being conducted in the Warta River basin.