Ocean Acidification

Increasing man-made carbon dioxide is synonymous with climate change. Emissions from vehicles, factories, and airplanes along with decreasing forests and vegetation to photosynthesize the CO2 are used to explain why changes in temperatures and weather patterns have changed so drastically in the last two centuries. But there is another consequence of increased CO2 in our atmosphere that has, so far, gone under the rader - ocean acidification.

Ocean acidification is a term used to describe the ocean's pH levels dropping due to increased absorption of carbon dioxide. Very little is actually known about ocean acidification and whether it is a real threat or not. Some believe that an increase in acidity could benefit life in the ocean, as suggested by Dr. J Floor Anthoni in 2005 (see link). The majority of the scientific world however, goes against his train of thought. They believe this is a major threat to the ocean.

Recent studies done by the National Research Council have detected a change in pH from 8.2 to 8.1 since the dawn of the Industrial Revolution. Considering how large the ocean is, and how much carbon dioxide it can absorb, this is a significant change. They predict that by the end of the 21st century, this pH level may drop another 0.2 to 0.3 base units, to below 8.0.

The long-term consequences are unknown, but recent data could be used as a bell weather for what's to come if the trend does not reverse. Studies on a plethora of marine organisms have shown changes in photosynthesis, reproduction, and biological processes. Coral reefs are also in danger because of increased water temperatures and acidity. Mongabay.com posted an article last year relating to the Australian coral reef system (see link). Increased temperatures kill off or scare away protozoa, called zooxanthellae, that live in the coral reefs providing it nutrients. This causes 'bleaching' which has become a major problem in Australia.

As well, "acidification ... reduces the availability of free carbonate ions in sea water, making more difficult for marine organisms to extract calcium carbonate to build the aragonite and calcite shells and skeletons they need to survive. Some of the most affected creatures are tiny polyps that build coral reefs... leaving them vulnerable to weathering from wave action and other stress."

These tiny creatures are the foundation of nearly all marine life food chains. The survival of plankton and bacteria are key to the survival of the entire ocean ecosystem. Since much of the sea life in the ocean ends up on our plates, this should be a concerning thought for seafood lovers.

Recent data suggests that commercial fish stocks will disappear by the year 2050, unless drastic conservation efforts are ramped up, because of over fishing. Take into account ocean acidification and its potential, these estimates could bring the extinction of seafood even closer than we think. At the current pace of fish losses, the last currently commercial fish stock would disappear in 2048 (see link).

Ocean acidification is a problem I wanted to bring to light. It has not been given the same level of publicity and attention that it deserves. Although we don't know for sure if the threats are real, humans should still take care of the ocean. BP's oil spill shows us that the ocean's ecosystem is fragile and it can not resolve our negligence on its own. Spread the word if you care about all the little Nemos out there.

Photo: http://www.maths.uq.edu.au/~nb/research/pictures/whitecoral.jpg