If were right on the edge now based on a starting point of 310 parts per million, Hales said, we may have to assume that CO2 levels will gradually increase through the next half century as the water that originally was exposed to increasing levels of atmospheric carbon dioxide is cycled through the system. Whether those elevated levels of carbon dioxide tip the scale for aragonites remains to be seen.
But if we somehow got our atmospheric CO2 level to immediately quit increasing, Hales added, wed still have increasingly acidified ocean water to contend with over the next 50 years.
Hales says it is too early to predict the biological response to increasing ocean acidification off North Americas West Coast. There already is a huge seasonal variation in the ocean acidity based on phytoplankton blooms, upwelling patterns, water movement and natural terrain. Upwelled water can be pushed all the way onto shore, he said, and barnacles, clams and other aragonites have likely already been exposed to corrosive waters for a period of time.
They may be adapting, he said, or they may already be suffering consequences that scientists have not yet determined.
You cant just splash some acid on a clamshell and replicate the range of conditions the Pacific Ocean presents, Hales said. This points out the need for cross-disciplinary research. Luckily, we have a fantastic laboratory right off the central Oregon coast that will allow us to look at the implications of ocean acidification.
|Contact: Burke Hales|
Oregon State University