St. Lawrence River zones that are hostile to invasive species can be refuges for native fish

The round goby is an invasive fish that has become established in the St. Lawrence River over the past two decades, following its introduction into the Great Lakes. (Cristina Charette), Author provided

Biological invasions are among the main factors contributing to the significant decline in biodiversity worldwide.

Several invasive species, such as the zebra mussel (Dreissena polymorpha) are native to the Ponto-Caspian region, which includes the Black, Caspian and Azov Seas, and were imported to North America by transoceanic ships. These species are known to have disrupted ecosystems around the world, including those of the Great Lakes and St. Lawrence River.