Karen Telleen-Lawton: Why Ocean Acidification Matters to Us
Remember the old tooth-in-Coke experiment? They said that soaking a tooth in cola overnight could dissolve it. That’s not precisely true, nor would anyone slosh cola 24 hours a day. Still, the American Dental Association reports a positive association between soft drink consumption and dental erosion. It made me think about what happens to ocean creatures, whose shells are also made of calcium, when they are subjected to an increasingly acidic environment?
We’re now running a perpetual worldwide experiment increasing the acidity of the ocean. Ocean acidification (OA) defines this progressive increase in the sea’s acidity, which is caused primarily by their uptake of carbon dioxide (CO2) from the atmosphere.
OA is attributed to human-generated atmospheric carbon dioxide: mostly from fossil fuels but also from land use changes. It has been well documented by hundreds of researchers globally over several decades.
The ocean’s acidity (measured by a falling pH) is now 30 percent more than it was in the pre-industrial era. By 2100, scientists estimate the pH values will have doubled from the pre-Industrial era.
So what does this matter?
The most damning result, found both in science labs and the seas creature measurements, is the dissolving of shells that form the protective outer surface of many sea organisms. Shell-forming marine organisms such as corals, bivalves (oysters, clams, mussels), pterodods (free-swimming snails) and certain phytoplankton are most affected.
Even in shell-less species, changes in pH and carbonate chemistry force marine organisms to spend more energy regulating chemistry in their cells. For some organisms, this may leave less energy for other biological processes like growing, reproducing or responding to other stresses.
There’s some irony in considering one of Coca-Cola's slogans, from 2011, “Life begins here.” Life on Earth, scientists tell us, began in the ocean. And while ocean acidification won’t kill all ocean life, many scientists think we will see changes in the number and abundance of marine organisms. Marine ecosystems may be populated by different, and potentially fewer, species in the future. It’s unclear if these impacts will be reversible.
Areas that could be particularly vulnerable to increasing acidity are where there is a natural upwelling of colder, low pH, deep water onto the shallow continental shelves. This is exactly the geography of our Santa Barbara Bight, where the ocean depth increases dramatically about midchannel. So we might be more than interested in proposals on the table.
Proposals for reducing the effects of OA include geo-engineering ideas to cool the warming planet. But this won’t tackle the chief cause, which is excess atmospheric carbon dioxide. Other ideas involve capturing CO2 and storing it away from seawater. One such project is “Blue carbon,” which seeks to offset CO2 levels by sequestering it in salt marshes, mangroves and sea-grass meadows. These projects can buy time, but don’t address the root cause of excess carbon dioxide emissions, which can only be effectively handled on a national and international scale.
We can do our part by choosing alternatives to fossil fuel wherever possible. But the problem is bigger than we are. In June, President Barack Obama announced measures to protect some of the world’s oceans with marine sanctuaries to address multiple issues, including pollution, overfishing and ocean acidification. It remains to be seen whether Congress will be willing to pass them.
— Karen Telleen-Lawton’s column is a mélange of observations spanning sustainability from the environment to finance, economics and justice issues. She is a fee-only financial advisor (www.DecisivePath.com) and a freelance writer (www.CanyonVoices.com). Click here to read previous columns. The opinions expressed are her own.