Increasing levels of acidity in the world’s oceans –- caused by excess carbon dioxide in the Earth’s atmosphere from the burning of fossil fuels –- are threatening several species of sea creatures, according to a study in this week’s issue of the Proceedings of the National Academy of Sciences. The researchers, led by Timothy Wootton of the University of Chicago, compiled eight years of acidity, salinity, temperature, and other measurements from probes at Tatoosh Island, Wash., which is located just off the Olympic Peninsula.
Oceans absorb about a third of the CO2 released into the atmosphere, and when the CO2 dissolves in water, it forms carbonic acid, which alters the ocean’s chemical balance. Acidic ocean water can cause seashells to dissolve; researchers in this study discovered that the increasingly acidic water of Tatoosh Island caused mussels (above) and barnacle populations to decline. Scientists are also concerned that any sea creatures with shells, including oysters, crabs, and lobsters, could also be at risk as the oceans become more acidic.
The researchers found that the acidity increased more than 10 times faster than predicted by climate simulations. “Our worry is that this might be happening faster than people thought,” says Wootton. “We hope this study will prod people to do more research into this.”
Bob Swanson & Doyle Rice, USA Today, 24 November 2008. Article.
The definition of “acidic” in the Oxford English dictionary is “having the properties of an acid; having a pH of less than 7”. This definition does not apply to un-manipulated seawater now nor in the foreseeable future. Hence, the adjective “acidic” should not be used. Note that there are some exceptions, for example in the immediate vicinity of CO2 vents.