SCIENCE: Climate change impacts stream life

[EcoPolis]

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Climate change impacts stream life
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Climate change is warming Welsh streams and rivers, affecting the
number and variety of some of their smallest animals, a major Cardiff
University study has found.

Rivers and streams are key ecosystems for many aquatic species and
form important links with surrounding habitats, yet little emphasis
has been given so far to the ecological effects of climate change on
these running-waters.

Now a twenty-five year study at Llyn Brianne in central Wales, led by
Professor Steve Ormerod and Dr Isabelle Durance of the Cardiff School
of Biosciences, has examined for the first time the effects of climate
change on stream species.

The study looked at the effects of climate change on stream
macroinvertebrates - animals that can be seen with the naked eye such
as crustaceans, snails and larval insects including stoneflies or
mayflies.

Professor Ormerod, said: "Streams and rivers are likely to be highly
sensitive to climate and yet long-term evidence of effects is scarce
globally. Our study shows a clear climate-change signal over the last
25 years, with temperatures warming faster than could be explained by
background variations. An ecological response to warming has also been
clear."

The study predicts that at the present rate the springtime abundance
of macroinvertebrates in streams could decline by as much as 21 per
cent for every 1 degree Celsius rise in temperature.

Dr Durance added "The numbers of species in the streams we examined
might also fall by 12-25 per cent if trends continue as expected over
the next 50 years".

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The study also examined how climate change interacts with other
problems in streams such as the effects of acid rain and formed part
of a project ('PRINCE') aimed at preparing for the impacts of climate
change funded by the Environment Agency, Countryside Council for Wales
and Natural England.

(Source: Cardiff University)