Ecosystem consequences of potential range expansions of Orconectes virilis and Orconectes rusticus crayfish in Canada — a review

摘要

Canadian water bodies are presently experiencing fluctuations in orconectid crayfish ranges largely as a result of human activities. The range of Orconectes virilis, Canada's most widespread crayfish, is expanding westward into previously uninhabitedwater bodies of Alberta. This species is also set to re-colonize watersheds in the eastern extent of its range as post-acidification recovery of aquatic ecosystems continues. In addition, the non-native Orconectes rusticus has invaded Central Canada. This species has the potential to rapidly invade boreal water bodies and out-compete native congeners, including O. virilis. Both these crayfish species are known to affect benthic ecosystems and their invasions may have adverse consequences for Canadian water bodies if left unchecked. Here we review the current documented distribution of O. virilis and O. rusticus in Canada, and identify the potential impacts that their invasion may have on boreal aquatic ecosystems. Finally, we consider options that resource managers might consider to contend with these invasions.