We’ve all seen the headlines about melting sea ice in the Arctic. It is tangible harbinger EVIDENCE of the enormous quantities of carbon dioxide, or CO2, our industrial world has pumped into the atmosphere.
But there is another equally insidious peril below sea level. Alaskans are at the forefront of “the other carbon dioxide problem” — ocean acidification. Some of the CO2 pollution dissolves into the ocean, creating carbonic acid and making the ocean more acidic.
No one fully knows what this change will do to the oceans. But we do know that if we don’t reverse this soon, we’ll end up with a drastically different ocean, to the detriment of nearly everyone who depends on it. Think jellyfish instead of salmon.
Acidification makes it harder for organisms to make shells or other protective structures — they essentially dissolve in the more acidic water. This change poses new risks for a vast range of ocean life, from clams and coral reefs, to crabs, shrimp, lobsters, krill, sea urchins, sea snails, and some kinds of plankton, to name a few.
Acidification can affect the growth of marine plants and the potency of many marine toxins. It makes it harder for animals in general to breathe. It makes fish grow oversized ear bones, called otoliths, potentially affecting their ability to orient themselves in the water.
It even makes the ocean noisier, by increasing the efficiency of sound transmission. It very likely does a lot of other things that haven’t been discovered yet.
Natural volcanic vents that produce CO2 provide a glimpse of how marine ecosystems respond to acidification. The view is bleak. Calcifying organisms like clams, corals and crabs disappear. The marine food web is drastically simplified, and the ocean loses its ability to support fish and other species that humans like to harvest, including the salmon, halibut, crabs and other bounty we enjoy here in Alaska.
A more acidic ocean will be fundamentally alien to human experience.
Because carbon dioxide dissolves better in colder water, ocean acidification is happening fastest near the poles, including here in Alaska. Essentially irreversible ocean changes are expected along Alaska’s Arctic continental shelf within a decade. If acidity is allowed to triple by the end of this century, it could transform the ocean into something fundamentally alien to human experience.
There is only one practical way to avoid ocean acidification, and that is by reducing our emissions of carbon dioxide. The United States is responsible for 20 percent of global emissions, and because we are so wasteful in our energy use, we have the best opportunity to reduce emissions.
As individuals, we can all take simple actions: turn off lights, inflate car tires to proper pressure, put high energy-using items like water heaters on timers.
Dr. Jeffrey Short & Jim Ayers. Anchorage Daily News, 27 August 2009. Full article.