Oceans becoming acidic 'at fastest rate for 65 million years'

The oceans are becoming more acidic at a faster rate than for 65 million years as a result of climate change, a report warns.
The Telegraph 27 Apr 09;

The Marine Climate Change Impacts Partnership (MCCIP) report card said the increasing acidity of the oceans caused by carbon dioxide could affect the climate further and hit wildlife.

The "ecosystem linkages" report, which looked at the links between different impacts of climate change, also said there had been large reductions in Arctic sea ice and declines in some seabirds as a result of changes to the seas around the UK.

It warned climate change could increase the likelihood of non-native species thriving in the UK's marine environment, while coastal communities faced threats such as flooding and opportunities including tourism in the future.

The different impacts of a changing climate on our seas are magnified because of their links to one another, the report said, and a "bigger picture" approach is needed to address the problems.

The oceans are a huge store of carbon dioxide, which dissolves in the water, and therefore play a significant role in maintaining stability in the climate.

The absorption of more carbon dioxide from the atmosphere as a result of higher emissions makes the seas more acidic, and in the last 200 years ocean acidity has increased by 30%.

The increase is at a rate much faster than any time in the past 65 million years, the report warned.

The increase in CO2 in the ocean will lead to a slowdown in its ability to absorb the greenhouse gas, leaving more in the atmosphere.

Rising acidity will also hit marine creatures including plankton and shellfish, damaging their ability to grow and reproduce, and in the cases of organisms such as corals reduce their capacity to build shells.

The report said that in the UK, the growing acidity could hit multi-million pound fisheries and aquaculture, while the global value of corals - through food, tourism and shore protection - has been estimated at some 30 billion US dollars (£21 billion).

UK overseas territories are among those which could be affected by threats to corals.

In response to the threat, the Government today announced an £11 million, five-year project to investigate the effects of acidification on biodiversity, habitats, species and wider economic and social impacts in the north east Atlantic, Antarctic and Arctic oceans.

The report also warned that Arctic sea-ice was disappearing, with impacts on ecosystems, the climate, shipping routes and access to oil and gas under the Arctic.

In the last decade there has been a 35% decrease in summer sea ice, and a 15% reduction in winter ice cover, leading to changes in habitats and wildlife which could have knock-on effects in the UK.

The waters around the UK have also seen changes in the food chain in recent years, including shifts in plankton and fish distribution as a result of warming seas.

The changes have contributed to declines in species such as sandeels, which have hit seabirds including terns, black-legged kittiwakes and skuas - a trend which could continue as the seas warm.

But non-native species may find it easier to establish themselves in UK waters as a result of warming temperatures, leading to impacts on aquaculture such as poisoning of farmed animals and clogging of nets.

Coastal economies and communities face a whole range of challenges, including declines in traditional fisheries and increased flood and erosion risks, as well as opportunities including new fisheries and tourism, the study said.

The report was produced by five groups of experts for the MCCIP, a coalition of scientists, the Government and devolved administrations, agencies and charities.

Environment Minister Huw Irranca-Davies said: "Climate change is happening now, and its impact on the marine environment affects all of us.

"The fight against climate change and protection of the natural environment are inextricably linked, and we are witnessing unprecedented effects on our seas."

And he said: "Ocean acidification will be one of the biggest environmental concerns of this century, with major and far-reaching impacts.

"We need to understand much more about the scale and nature of the effect CO2 is having on our oceans and marine life."