Climate change setback for acidified rivers

December 3, 2008

Climate change is hampering the long-term recovery of rivers from the effects of acid rain, with wet weather offsetting improvements, according to a new study by Cardiff University.

The research, by Professor Steve Ormerod and Dr Isabelle Durance of the School of Biosciences took place over a 25 year period around Llyn Brianne in mid-Wales. Their findings are published online today in the British Ecological Society's Journal of Applied Ecology.

Carried out in 14 streams, the research involved assessing the number and variety of stream insects present each year, measuring concentrations of acid and other aspects of stream chemistry, and documenting 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 should have re-colonised the improving Welsh streams. Typical among them should be sensitive mayflies and other groups often eaten by trout and salmon.

Their findings, however, showed a large short-fall in biological recovery, with just four new species added to the recovering rivers sampled.

Professor Steve Ormerod, who has led the project since it began in the early 1980s, said: "Since the 1970's, there have been huge efforts to clean-up sources of acid rain, and our research shows that rivers are heading in the right direction. However, our results support the theory that acid conditions during rainstorms kill sensitive animals. During recent wetter winters, upland streams have been acidified enough to cancel out up to 40 percent of the last 25 years' improvements: climatic effects have clearly worked against our best efforts."

Dr Isabelle Durance, who co-authored the paper said: "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. A wider suggestion from our research is that by reducing these other environmental problems, we can minimise at least some climate change impacts."

Source: Wiley

Explore further: Study provides scenarios for assessing long-term benefits of climate action

Related Stories

Recommended for you

History shows more big wildfires likely as climate warms

October 5, 2015

The history of wildfires over the past 2,000 years in a northern Colorado mountain range indicates that large fires will continue to increase as a result of a warming climate, according to new study led by a University of ...

Asteroid impact, volcanism were one-two punch for dinosaurs

October 1, 2015

Berkeley geologists have uncovered compelling evidence that an asteroid impact on Earth 66 million years ago accelerated the eruptions of volcanoes in India for hundreds of thousands of years, and that together these planet-wide ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.