According to a new study published in the journal Frontiers in Ecology and the Environment water temperatures are increasing in many streams and rivers throughout the United States.
“Warming waters can impact the basic ecological processes taking place in our nation’s rivers and streams,” said Dr. Sujay Kaushal of the University of Maryland Center for Environmental Science (UMCES) and lead author of the study. “Long-term temperature increases can impact aquatic biodiversity, biological productivity, and the cycling of contaminants through the ecosystem.”
The study focused its attention on 40 streams and rivers throughout the US, and found that 20 showed “statistically significant long term warming trends.” The annual mean water temperature increased by 0.02-0.14°F (0.009-0.077°C) per year and could often be correlated with increases in air temperature. Rates of warming in these streams were found to be most speedy in urbanized areas.
“It’s both surprising and remarkable that so many diverse river systems in North America behaved in concert with respect to warming,” said Dr. David Secor of the UMCES Chesapeake Biological Laboratory who himself has seen a 3°F increase in Maryland’s Patuxent River since 1939.
A total of 20 increases in temperature left 20 rivers not adhering to the overall temperature rise, including 13 increases that were not statistically significant and 2 whose temperatures decreased. The river with the longest record of increase was the Hudson River Poughkeepsie, New York, and the river with the most rapid rate of increase was the Delaware River near Chester, Pennsylvania.
“We are seeing the largest increases in the most highly urbanized areas which lead us to believe that the one-two punch of development and global warming could have a tremendous impact on stream and river ecosystem health,” said Dr. Kaushal.
The press release from the University of Maryland Center for Environmental sciences says concludes;
Given long-term global warming and “urban heat island effects” related to the abundance of buildings, roads, concrete, and asphalt, the authors point out that conserving riparian forests, reducing impervious surfaces, adopting “green” infrastructure practices, and reducing greenhouse gas emissions can help reduce increased water temperatures.
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