Cancun/Nairobi/Plymouth,
2 December 2010 - The future impact of rising
emissions on the health of seas and oceans
may be far more wide-ranging and complex
than was previously supposed, a new report
released at the UN climate convention meeting
in Mexico says.
The study, entitled
the Environmental Consequences of Ocean
Acidification, has brought together some
of the latest scientific research on 'ocean
acidification', a process triggered by increasing
concentrations of dissolved C02 which is
changing the sea's chemistry by lowering
the pH of the marine environment.
Launched by the United
Nations Environment Programme (UNEP), the
report confirms concerns that some organisms,
such as corals and shellfish may find it
increasingly difficult to form their skeletons
in the decades to come making it harder
to survive let alone thrive. It also shows
that ocean acidification can react together
with ocean warming so that animals such
as crabs have a reduced range of temperatures
they can thrive in.
This in turn may have
significant future impacts on catches of
crabs, mussels and other shellfish; species
dependent on coral reefs and ones such as
salmon that feed on smaller, shell-building
organisms lower down the food chain known
as ptetropods, for example.
Other new research is
spotlighting fresh areas of concern including
findings that some species, including the
clown fish made famous in the Disney cartoon
Finding Nemo, may find it harder to avoid
their predators and to find their way home.
If other fish react
the same way, this may have implications
for the marine food chain upon which billions
of people depend directly or indirectly
for protein and livelihoods.
Achim Steiner, UN Under-Secretary
General and UNEP Executive Director, said:
"Ocean acidification is yet another
red flag being raised, carrying planetary
health warnings about the uncontrolled growth
in greenhouse gas emissions. It is a new
and emerging piece in the scientific jigsaw
puzzle, but one that is triggering rising
concern".
'Whether ocean acidification
on its own proves to be a major or a minor
challenge to the marine environment and
its food chain is to date unknown. But the
phenomenon comes against a backdrop of already
stressed seas and oceans as a result of
over-fishing to other forms of environmental
degradation. Thus the public might quite
rightly ask how many red flags do governments
need to see before the message to act gets
through," he said.
The report was compiled
in collaboration with the Plymouth Marine
Laboratory in the United Kingdom and scientists
from other organisations including the National
Oceanography Centre in Southampton and the
Intergovernmental Oceanographic Commission
of UNESCO.
Carol Turley, a senior
scientist at the laboratory; Knowledge Exchange
Coordinator for the UK Ocean Acidification
Research Programme, and lead author of the
new report, said: "As scientists around
the world start to investigate the potential
impacts of ocean acidification, we are seeing
an overall negative impact from ocean acidification
directly on organisms and on some key ecosystems
that help provide food for billions. We
need to start thinking about the risk to
food security."
Dr. Turley stressed
that researchers were working on the frontiers
of science in respect to ocean acidification
and its potentially complex impact on the
marine environment and its organisms.
She added that some
research indicated that adult lobsters,
for example, might actually increase shell-building
in response to falling pH levels whereas
it may be the juveniles who are less able
to build healthy skeletons.
A similar possibility
may arise in respect to adult and juvenile
forms of fish with the olfactory or smelling
systems of some species of young fish impaired
but adults unaffected.
Meanwhile, there is
some evidence of other curious changes if
emissions continue to rise and concentrations
of C02 continue to build-up in the seas
and oceans. For example, brittle stars,
an important part of the marine food chain,
may increase shell-building at the cost
of muscle formation, some science suggests.
"It is clearly not enough to look at
a species. Scientists will need to study
all parts of the life-cycle to see whether
certain forms are more or less vulnerable.
Meanwhile, the ability, or inability, to
build calcium-based skeletons may not be
the only impact of acidification on the
health and viability of an organism: brittle
stars perhaps being a case in point,"
said Dr. Turley.
The report points out
that there may be "winners" as
well as "losers", with photosynthetic
organisms such as seagrasses likely to benefit
from rising acidification. Yet studies of
natural C02 vents in the Mediterranean Sea
show that although there are some "winners"
the ecosystem is likely to be altered in
other ways.
The report calls on
governments, policymakers and others to
consider a range of actions including:
- Rapid and substantial
cuts to man-made CO2 emissions to the atmosphere
in order to reduce ocean acidification;
- Determine the vulnerability
to ocean acidification of human communities
dependent on marine resources;
- Identify species that
are more flexible to change and assess how
these may affect ecosystems and food security;
- Reduce other pressures
on food fish stocks to provide the best
chance of success through, for example,
marine spatial planning or re-evaluating
available resources and their usage;
- Assess the options
for the development of environmentally sustainable
'aquaculture' options using species that
may be more resistant to lowered pH;
- Embrace the science
of ocean acidification into fisheries management
tools.
Notes to Editors
Key Findings from the
Report
Around 25 per cent of
the world's C02 emissions are being absorbed
into the seas and oceans where it converts
to carbonic acid.
This is lowering the
pH of the oceans and affecting its chemistry.
For example, the concentrations of carbonate
ions is decreasing and is linked to the
ability of many marine organisms to build
reefs and shells.
- The report says that
the chemistry of the oceans is being altered
at a speed not seen for 65 million years
since the extinction of the dinosaurs;
- The mean pH of the
marine world has decreased by 30 per cent
and the concentration of carbonate ions
has fallen by 16 per cent since the industrial
revolution;
- Based on current rates
of CO2 emissions, projections show that
by the end of the 21st century, global ocean
pH will decrease by a further 0.3 units,
which represents a total increase in acidity
of 150 per cent.
Fish including shellfish
contribute 15 per cent of animal protein
for three billion people worldwide, and
a further one billion people rely on fisheries
for their primary source of protein.
- The report says that
many marine organisms have ways of compensating
for changes in seawater chemistry, although
they may have to spend more energy doing
this in an increasingly more acidic ocean;
- However, studies of
mussels and sea urchin species have shown
that they have only a partial or no compensation
mechanism, potentially making them more
vulnerable.
Around 80 per cent of
fish catches occur in just 10 per cent of
the oceans, including key areas such as
Continental shelves and estuaries.
- The report says that
"many of these areas are also projected
to be very vulnerable to ocean acidification
this century";
The aquaculture industry
is the fastest growing food producer worldwide,
increasing at a rate of 7 per cent per annum
and the proportion of fish produced by aquaculture
and consumed by humans worldwide has risen
to 50 per cent of total production.
- The report says that
these industries are now at risk from future
ocean acidification both directly through
the impact on the organisms themselves and
indirectly through the food webs and habitats
they depend on.
Tropical reefs provide
shelter and food for an estimated 25 per
cent of known marine fish species, and account
for between 9 and 12 per cent of world fish
landings.
Consequently, these
coral reefs provide food and livelihood
security for some 500 million people worldwide.
- The report says it
is anticipated that future ocean acidification
is likely to affect adult and juvenile coral
growth and recruitment, coralline red algae
growth, reef structural integrity and potentially
even the density of bio-eroding grazers
and predators.
UNEP Emerging Issues:
Environmental Consequences
of Ocean Acidification:A Threat to Food
Security is available at http://www.unep.org/dewa/pdf/Environmental_Consequences_of_Ocean_Acidification.pdf
The report is being launched at the 16th
Conference of the Parties to the UN Framework
Convention on Climate Change taking place
in Cancun, Mexico, from 29 November to 10
December 2010 http://unfccc.int/2860.php