According to recent reports from the Journal Science, the world’s oceans are becoming acidic faster than at any time in the past 300 million years.
Increased levels of carbon dioxide, now at 394 ppm, are causing the world’s oceans to grow more acidic. A 2010 study from the scientific journal Nature showed that the oceans were becoming acidic at a rate ten times faster than at any time in the last 55 million years. Now, the new study shows that ocean acidity is growing at a rate most current sea creatures have never experienced.
The Science study collected data from sediment cores in order to gain information on past ocean acidity. The lead researcher, Bärbel Hönisch, a paleoceanographer at Columbia University’s Lamont-Doherty Earth Observatory, noted that past spikes in ocean acidity resulted in major losses of marine species. Barbel seemed concerned about species key to fishing and tourism saying “if industrial carbon emissions continue at the current pace, we may lose organisms we care about—coral reefs, oysters, salmon.”
Acidification causes stress to ocean creatures that build shells out of calcium, which the increasing acidity dissolves. This threatens creatures who serve as food and habitat builders for many ocean species. Of prime concern is the threat to ocean reef systems. Corals build their reefs out of calcium carbonate and rising levels of atmospheric CO2 put stress on these key species. It is estimated that more than a million species rely on ocean reefs for habitat. Stress to and loss of reefs would put most, if not all, of these creatures at extreme risk of extinction. Ocean researchers believe that it will not be possible for any corals to survive if CO2 levels reach 600-650 ppm. But current levels are already causing stress.
A combination of rapidly warming oceans, spiking ocean acidification, and reduced oxygen levels are creating a situation where an ocean mass extinction is inevitable if carbon dioxide emissions don’t stop soon. Since more than 1 billion people are fed by the world’s oceans, it is important to dramatically reduce these emissions soon.