By IANS,
London : Climate change is negating long-term recovery of rivers from the effects of acid rain, according to a Cardiff University study.
The research by Steve Ormerod and Isabelle Durance of the School of Biosciences took place over a 25-year period around Llyn Brianne in mid-Wales.
Carried out in 14 streams, the research involved assessing the number and variety of stream insects present each year.
Scientists measured concentrations of acid and other aspects of stream chemistry and documented climatic variation such as warmer, wetter winters.
With average acidity in rivers falling due to improvements in the levels of acid rain, the researchers expected that up to 29 insect species to have re-colonised the less acidic Welsh streams.
These included sensitive mayflies and other groups often eaten by trout and salmon.
Ormerod, a professor who has led the project since it began in the early 1980s, said that “since the 1970s, there have been huge efforts to clean-up sources of acid rain, and our research shows that rivers are heading in the right direction”, said a Cardiff statement.
Added Isabelle Durance, who co-authored the paper: “More and more evidence now shows that some of the worst effects of climate change on natural habitats come from interactions with existing stressors – in this case acid rain.” Their findings were published online in the British Journal of Applied Ecology.