A study published over the summer found that off the coast of Oregon, the Pacific Ocean is polluted with caffeine.
Researchers sampled two kinds of locations: ones near sewage treatment plants or river mouths and were labeled “potentially polluted” and remote ones near state parks that were less likely to be polluted. They found that caffeine levels in the potentially polluted waters were actually below the detectable limit (9 nanograms per liter), while levels in remote areas were much higher (about 45 nanograms per liter).
“Wastewater-treatment plants, for the most part, have to do regular monitoring to ensure they are within certain limits,” study co-author Elise Granek, a Portland State University marine ecologist. However, Granek noted that caffeine is unregulated and therefore not monitored.
“Our hypothesis from these results is that the bigger source of contamination here is probably on-site waste disposal systems like septic systems.” she said. With on-site disposal systems, “there is frequently not much monitoring going on.”
Caffeine has been found in waters across the globe, including Boston Harbor, Puget Sound, the Mediterranean and the North Sea. Even though it’s been documented, the impact of caffeine on marine life is unknown.
“Caffeine is pretty darn ubiquitous, and there is growing evidence that this and other understudied contaminants are out there,” said Dana Kolpin, of the USGS’s Toxic Substances Hydrology Program in Iowa City, Iowa.
Koplin, who was not directly involved in the study, explained that if there is caffeine in the water, there are probably a lot of other contaminates, “including pharmaceuticals, hormones, personal-care products like detergents or fragrances, even artificial sweeteners.”
“With caffeine, we’re not yet sure about its environmental effects,” Kolpin continued. “But it’s a very nice tracer, even if it doesn’t have a large effect, because in most parts of the world, you know that this is coming from a human waste source.”
To learn more:
- Read this article from National Geographic: Caffeinated Seas Found off U.S. Pacific Northwest
- Find the full study, published in the Marine Pollution Bulletin, here: Occurrence and concentration of caffeine in Oregon coastal waters
Copyright © 2013 by Marine Science Today, a publication of Marine Science Today LLC.