Lyrics:

As the oceans absorb man-
made carbon emissions a
chemical reaction takes place
which is making sea water
more acidic. This subtle shift
in pH level is having a profound
effect on the sea animals
which use calcium carbonate
to form their shells and
skeletons and Marine Biologists
are now discovering that this
could have implications across
the world's oceans. Already
shellfish industries in America
are being adversely affected
and scientists are working
hard to predict how the world's
fisheries might respond in the
future. Professor Alice Roberts
discovers there are surprising
lessons to be learnt from the
past and hears why immediate
action is needed to prevent
further threats to biodiversity.
Producer: Helen Lennard.