Tinca tinca

The tench (Tinca tinca) is a globally invasive cyprinid fish that was illegally released into the Richelieu River in 1991, and had subsequently spread into the St Lawrence River where it became established circa 2006. Since that time, the number of tench captured by commercial fishermen in the river has increased exponentially. Its potential impacts include competition with native benthic fishes, increased transmission of parasites, reduced growth of macrophytes, and changes to benthic macroinvertebrate communities.

For more information on its invasion ecology, see the review by Avijas et al (2018).