USGS Study: Chesapeake Tributaries Are Warming, Pollution May Increase

"A slight increase in air temperature over the past half-century has caused waters to warm more than two degrees in tributaries to the Chesapeake Bay, a change that could reduce the expected benefits of the multibillion-dollar bay cleanup plan and eventually alter the behaviors of marine animals, a new study says.

The mean temperature of the bay’s tributaries is about 2 1/2 degrees higher now than in 1960 as a result of climate change, according to the study by two U.S. Geological Survey hydrologists. Although that doesn’t seem like much, warmer water allows phosphorous, a type of nutrient pollution, to rise from sediment in the bay at a faster rate.

'We expected that we’d find a link between rising air temperature and water temperature,' said John Jastram, who co-wrote the study with Karen Rice. But they were surprised to find that even in the northernmost parts of the 64,000-square-mile watershed, such as Pennsylvania near its border with New York, temperatures in brooks and streams increased significantly."

Darryl Fears reports for the Washington Post December 10, 2014.