Rising carbon dioxide levels don't just spell trouble for terrestrial creatures; they're also contributing to changes in the ocean's chemistry that threaten vast swaths of ocean life.
A new study led by a Swiss research team and published in the journal Science on Thursday predicts that by 2050, waters just off the western coast of the U.S. will become acidic enough that ocean-dwelling creatures like mussels, oysters and corals won't be able to form their shells or skeletons.
The waters off the coast of California, Oregon and Washington are particularly fertile because of winds that blow surface water out to sea, causing nutrient-rich water to well up near the shore. But this upwelling means those waters tend to be naturally more acidic, making them especially vulnerable to ocean acidification. This process occurs as the ocean absorbs carbon dioxide and is expected to accelerate as the levels of greenhouse gases emitted by humans continue to rise.
As carbon dioxide dissolves in sea water, it reduces the saturation levels of the mineral calcium carbonate, a key component in the shells and skeletons of ocean creatures. That undersaturation can build up to dangerous levels and deprive these animals of the basic building blocks they need to maintain their shells.
The researchers say even in optimistic models, calcium carbonate will be rapidly less saturated along the California coastline. By 2050, seawater in that region will no longer have a sufficient year-round saturation state, according to the researchers.
I was really surprised to see how quickly some of these changes will be occurring, lead researcher Nicolas Gruber told the Christian Science Monitor.
While the team doesn't yet exactly know how various ocean organisms will be impacted by the change, mussels appear to be most at risk from ocean acidification.
Our study is an example of how mankind is about to exhaust the limits of what an ecosystem can tolerate, Gruber said in a statement.