One would expect that beaver dams create more harm than good for fish populations, as they block certain species from swimming upstream and therefore reduce the availability of suitable spawning habitat. However, according to a new study by the University of Southampton, reintroduced European beavers could have an overall positive impact on Scottish wild salmon populations.

Funded by Scottish Natural Heritage, a study was conducted to analyze the relationship between beavers and salmon populations due to underlying economical concerns that beavers can harm fish stocks by obstructing migration. But after surveying 49 fisheries managers, scientists, and beaver ecology experts from Europe and North America, more than half of those who responded believe that the overall impact of beavers on fish populations is beneficial.