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epoca-picsOcean Acidification (OA)

The consequences of man’s use of fossil fuels (coal, oil and natural gas) in terms of global warming has not escaped anyones attention. Ocean acidification is another, and much less known, result of the approximately 79 million tons of carbon dioxide (CO2 ) released into the atmosphere every day, not only as a result of fossil fuel burning but also of deforestation, production of cement and changes in the way land is used. Since the beginning of the industrial revolution, about one third of the CO2 released in the atmosphere by anthropogenic (human-caused) activities has been absorbed by the world’s oceans, which play a key role in moderating climate change. Without this capacity of the oceans, the CO2 content in the atmosphere would have been much higher and global warming and its consequences more dramatic. However, the CO2 dissolves into seawater and produces a weak acid which makes the seawater more acidic. Initially scienitists believed that the inertia of the ocean would prevent the pH (a meausre of acidity) from changing. But observations and recent studies now show that the extreme speed of the CO2 invasion caused by man, a 100 times quicker than has ever happened in the past 25 million years, has prevented the ocean from buffering changes and the whole of Earths oceans are acidifying.

Click to find out more about the chemistry

The impacts of ocean acidification on marine ecosystems are still poorly known but one of the most likely consequences is the slower growth of organisms forming calcareous skeletons or shells, such as corals and molluscs.

Scientists are now very concerned about how animals and plants in the ocean will react to our ever-increasing dumping of CO2 waste. Which organisms will survive and which will die? How will this affect the ecosystem, through food webs and through cycling of nutrients, chemicals and gases? There are still many unknowns.

Click to find out more about the biological unknowns

Investigating the impacts of a high-CO2 ocean has become a first priority on research agendas worldwide, leading us in Europe to launch EPOCA. In this framework we are preparing a major experiment in Spitzbergen, far remote in the icy Arctic ocean, where acidification is thought to strike first because of the low temperature of the water. We want to better understand what is happening in this critical area. We want to learn how Arctic marine life reacts to high-CO2 waters. We want to share our findings with the general public and we warmly invite you all to join us in the adventure!

Click to find out more about ocean acidification in the polar regions

Click to find out more about the experiments

Image References:
1.Calcidiscus. Today and in 2100. Ulf Riebesell.
2.Kiel mesocosm experiment. Andrea Ludwig.
3.Cavolinia inflexa. Steeve Comeau.
4.Posidonia oceanica lacking Corallinaceae at mean pH 7.6 in volcanic carbon dioxide vents. Hall-Spencer et al. 2008.
5.Orbulina universa. Jelle Bijma.
6.Gorgonia and Lophelia. Ulf Riebesell.
7.Live Patella caerulea in pH 7.4 in volcanic carbon dioxide vents. Hall-Spencer et al. 2008.
8.Cod Gadus morhua juvenile. Catriona Clemmesen.
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