An Oregon Sea Grant-funded study by Portland State University environmental scientist Elise Granek and colleagues, reported in the July issue of Marine Pollution Bulletin, suggests that suggest that wastewater treatment plants are effective at removing caffeine, but that high rainfall and combined sewer overflows can combine to flush the contaminants out to sea. The results also suggest that septic tanks, such as those used at the state parks, may be less effective at containing pollution.
Results of the study, funded in part by Oregon Sea Grant and NOAA, were published in the July 2012 Marine Pollution Bulletin. The study was conducted by scientists at Portland State University and Washington State University, Vancouver.
This research, the first to look at caffeine contamination off the Oregon coast, found elevated levels of caffeine at several sites in Pacific Ocean waters off the coast of Oregon—though not necessarily near the high-population centers where researchers expected to find it.
Starting in spring 2010, scientists collected and analyzed samples from 14 Oregon coastal locations and seven adjacent water bodies as far north as Astoria and as far south as Brookings. Researchers identified locations as potentially polluted if they were near wastewater treatment plants, large population centers, and rivers and streams emptying into the ocean.
The study found high caffeine levels near Carl Washburne State Park in Florence, and at Cape Lookout – two areas not near the potential pollution sources. Meanwhile, the researchers also measured low levels of caffeine near large population centers like Astoria/Warrenton and Coos Bay. They also found that caffeine levels spiked following a late-season storm of wind and rain that triggered sewer overflows.
Since no natural sources of caffeine grow in the Pacific Northwest, the findings suggest that additional human-caused pollutants could also be making their way into the ocean from storm-related overflows.
The study is currenty featured on the NOAA Research Web page, where you can read more about it.
(Photo by Fiona Henderson)