Impact Type: Deposition of pollutant
Mason and Macdonald (1987) have shown otter distribution along rivers in Wales to be restricted by acidity of the water. This is thought to be a secondary impact, as the otters are unable to find sufficient fish as prey. In a later study in Scotland, Mason and Macdonald (1989) found otters in all areas they surveyed. This is possible because otters in Scotland feed on a greater range of prey. This suggests that, while acidification of rivers may not reduce the distribution of otters in Scotland, it may reduce the carrying capacity of the rivers and make the otter population there vulnerable to other environment stresses (Mason and Macdonald 1989).
In Wales Mason and Macdonald (1987) have shown that otters are not present in rive rs where the pH is lower than 5.5.
|Critical Load/ Level|
No estimate available