UK Scientists: Stream Acid Effects Slow to Disappear

Noting that continuous efforts to cleanup sources of acid rain have led rivers to recover much of their health, UK scientists say that the long-term effects of the problem, which peaked in the seventies and eighties, are not easily reversed. Interestingly, it appears that “adding lime (calcium carbonate) to soils to reduce acidity had few long-term benefits compared with natural recovery.” “With average acidity in rivers falling, ecologists thought 29 insect species should have recolonised Welsh streams. Among them should be sensitive mayflies and other groups often eaten by trout and salmon. The findings, funded by Defra, the Natural Environment Research Council and others, however, showed a large short-fall in biological recovery.” From Planet Earth Online.