More acidic oceans could profoundly affect plankton

Climate Change
Microscopic ocean plants and animals may consume increasing amounts of carbon as oceans become more acidic, a new experiment carried out in the narrow fjords of Norway suggests. Scientists know that the world's oceans are becoming more acidic from the absorption of carbon dioxide from power plants, factories, and vehicles. Experiments have already shown that acidity could eat away at the shells of marine organisms and interfere with the physiology of others. But Ulf Riebesell of the Leibniz Institute of Marine Sciences in Germany found that when he exposed waters to the carbon dioxide levels of today and of those projected for 2100 and 2150, plankton - the community of tiny ocean plants and animals - consumed more carbon without consuming more nutrients. However, it's unclear whether this type of plankton consumption will be able to help lower carbon levels in the ocean, reducing climate change.

BOTTOM LINE: A more acidic ocean could have profound impacts on plankton communities that in turn could impact how much carbon dioxide the oceans absorb and emit.

CAUTIONS: The plankton community absorbs more carbon only under high levels of carbon dioxide. It's unclear what other biological changes will take place in the ocean when levels are that high.

WHAT'S NEXT: Scientists are planning to conduct similar experiments in the open ocean to see if their near-shore results are replicated.

WHERE TO FIND IT: Nature online, Nov. 11.

BETH DALEY

BACK PAIN

More than half of all Americans suffer low back pain in a given year, grimacing and walking gingerly for a few days or weeks before the agony subsides. Doctors generally provide reassurance, encourage activity, and suggest Tylenol for pain relief. Sometimes, they also prescribe medications such as diclofenac (an anti-inflammatory drug) or refer the patient for spinal manipulative therapy, provided by a chiropractor or an osteopath. Since these latter therapies can be costly and are often associated with side effects, researchers at the Back Pain Research Group at the University of Sydney, in Australia, decided to test whether they are useful in managing a sudden attack of low back pain. Led by investigator Mark Hancock, they looked at 240 patients and found that adding diclofenac and chiropractic treatments provided no additional benefit. Other anti-inflammatories, such as ibuprofen, are also unlikely to provide any faster relief.

BOTTOM LINE: "The majority of patients with low back pain will improve with conservative therapies," Hancock said.

CAUTIONS: This study explored only patients with acute or sudden attacks of low back pain that lasted less than six weeks, rather than those with chronic back pain, for which the management differs. It also did not consider other interventions, such as exercise.

WHAT'S NEXT: The researchers hope to shed more light on the causes of back pain in hopes of identifying better treatments.

WHERE TO FIND IT: The Lancet, Nov. 9.

SUSHRUT JANGI