“What happens when you kill several million beavers and all of those beaver dams break down and all of those ponds drain? Well, it’s this immense loss of habitat for cutthroat trout and moose and wood ducks and boreal toads,” Goldfarb said. “Historians have referred to the fur trade as the aquatic Dust Bowl, this vast elimination of riparian habitat that profoundly shaped streams all over the continent.”
https://www.bozemandailychronicle.com/news/beaver-believer-how-north-america-s-keystone-species-shapes-our-ecosystems/article_afaeed0a-d768-11ef-b9b2-f337165b8bcc.html