Acid Seas Kill Off Coral Reefs

international | environment | other press Wednesday March 01, 2006 20:24 by Terence - none

Increasing acidity of seas caused by absorption of CO-2

In the report linked to below, it describes how the acidity of the oceans has increased because the rate of carbon dixoide absorption has shot up.

Many marine creatures such as corals and sea-shells of all kinds have carbonate shells which are sensitive to the acidity (or pH level) of the water and means they may start dissolving. This would have enormous repercussions for the entire oceanic ecosystems.

This report is really a measure of how far we have pushed the stability of the entire global ecosystem. It describes how the rapid increase in carbon dixoide over the last 100 years has resulted in essentially a pulse (viewed from a longer timeframe) of CO-2 being absorbed by the oceans

As anyone knows from school chemistry, dissolving CO-2 in water creates carbonic acid, while not the strongest of acids, is an acid nevertheless and as reported is enough to cause a change in the pH or acidity level of the water.

When we consider this report, along with many others for example that are reporting the rapid metling of the polar sea ice cover, I think we have to be worried. It's not a case of maybe we are running out of time or soon it will be too late. The fact is, it's already too late and we have ran out of time. Anything we do now and so far we are doing zero, can only result in modifying the degree of change, but change is already underway and it ain't pretty.

Here's some extracts from the report:

Researchers have found that carbon dioxide, the gas already blamed for causing global warming, is also raising the acid levels in the sea. The shells of coral and other marine life dissolve in acid. The process is happening so fast that many such species, including coral, crabs, oysters and mussels, may become unable to build and repair their shells and will die out, say the researchers.

AND

Caldeira found, however, that the huge volumes of carbon dioxide being released by humans are dissolving into the oceans so fast that sea creatures can no longer absorb it. Consequently, the levels of carbonic acid are rising and the oceans are “turning sour”.

Speaking at the American Geophysical Union’s ocean sciences conference in Hawaii last week, Caldeira said: “The current rate of carbon dioxide input is nearly 50 times higher than normal. In less than 100 years, the pH (measure of alkalinity) of the oceans could drop by as much as half a unit from its natural 8.2 to about 7.7.”

This would mark a huge change in ocean chemistry. The shells of marine creatures are made of calcium carbonate, the same substance as chalk, which is vulnerable to acidity. Even a slight increase in acidity would mean many creatures would dissolve. Others might be able to rebuild their shells but would be unable to reproduce.

AND

Such a loss would have disastrous consequences for larger marine animals such as salmon, mackerel, herring, cod and baleen whales. These all feed on pteropods, or sea butterflies, one of the species most threatened by rising acidity.