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Ocean acidity studies raise more yellow flags

New reports indicate that ocean acidification is becoming a real problem in waters off of Washington State and could affect the Southern Ocean a lot sooner than we thought. The first study shows that, over the last eight years, waters near Tatoosh Island, Wash., have become acidic 10 times faster than predicted. The changing seawater…read more »

New reports indicate that ocean acidification is becoming a real problem in waters off of Washington State and could affect the Southern Ocean a lot sooner than we thought.

The first study shows that, over the last eight years, waters near Tatoosh Island, Wash., have become acidic 10 times faster than predicted. The changing seawater pH has killed 10-20 percent of the mussels on the island. Scientist J. Timothy Wootton of the University of Chicago said that rising ocean acidity could kill 60-70 percent of the the mussels in the coming decades. The NPR article about the study notes that “Mussels provide shelter for many animals that live along the tide line. They form a key part of the food web that includes the fish we eat.”

A separate study describes how the tipping point for acidification in the Southern Ocean may come in 2030, rather than 2060 as previously thought. That’s because plankton with calcium carbonate shells in the Southern Ocean appear to be more vulnerable to rising acidity at certain times of the year. Because these plankton form the base of the food chain, a large die-off could impact organisms higher up the chain, such as fish, dolphins and whales.

I also saw that in the latest issue of Science, Canadian scientists have shown that a decline in calcium in freshwater lakes correlates to a decline in crustacean zooplankton — which form the base of the food webs in these lakes. The study further shows that a large proportion of Ontario’s lakes will soon have dangerously low calcium levels. In these cases, the calcium decline can be traced back to increasing acidic soils, caused by acid rain and the impacts of timber harvesting.

We should be concerned about the acidification of our oceans and lakes, because of the effects on ocean life and the food chain. I wrote about this issue back in May, when a study came out showing how acidified sea water was coming up from the deep ocean along the U.S. West Coast some 100 years before scientists had predicted. Now, these more recent studies further illustrate how serious a problem ocean acidification is — and will be.

The image I’ve used is from a NOAA animation of how calcium levels are predicted to fall between now and 2100. Click here or on the image to see the brief movie, or read about the data and the movie here. Blue and purple areas indicate low levels of calcium carbonate, due to more acidic waters. The Xs represent coral reefs, which are in danger of dissolving if waters become too acidic.

Dan Kulpinski