By Richard A. Lovett
PORTLAND, Ore. – In presentations at the 2018 Ocean Sciences Meeting several Oregon Sea Grant-funded scientists reported that chemicals ranging from Prozac to an anti-diabetic drug are finding their way into the ocean.
Pharmaceuticals are of particular concern because they are intended to be biologically active, even at low doses, said Elise Granek, an environmental scientist at Portland State University who is conducting research funded by Oregon Sea Grant.
Scientists have known for several years that these chemicals are a problem in lakes and rivers, Granek said, but the realization that they might also be a problem in the ocean is much more recent. When she first started looking at the issue in 2015, she said, there were hundreds of studies about their effects in the narrower confines of fresh-water environments, but “only on the order of dozens in the marine environment.”
The levels of these compounds found in coastal waters, however, are high enough to have significant effects on marine animals. For example, Granek said, fluoxetine (Prozac) affects mussel feeding, growth and reproduction. And as Joey Peters found out while he was an Oregon Sea Grant-funded Malouf scholar, it also makes crabs more active and bold around predators. Too bold, it turns out, because they wind up losing limbs or dying because they are more easily preyed upon.
Another of Granek’s graduate students, Amy Ehrhart, has found pharmaceuticals, including antibiotics and antifungal agents, in Pacific oysters at study sites from the southern Oregon coast to the central Washington coast.
These chemicals get to the ocean, she said, partly because people often flush them down their toilets if they have leftovers. As a way of protecting children from accidental poisonings, that’s effective, but wastewater treatment plants aren’t designed to remove them so allow them to pass through to rivers and eventually the sea.
But that’s not the only problem. Many pharmaceuticals pass through the body unchanged. Excreted in urine, they too wind up in wastewater treatment plants.
With funding from Oregon Sea Grant, Tawnya Peterson, an environmental health researcher at Oregon Health & Science University, has measured the concentrations of metformin, a medicine used to treat type II diabetes, in the Columbia River. From that, she has concluded that each day, 62 to 65 kilograms of the drug are reaching the Pacific Ocean, where coastal eddies can trap it for several days before it eventually disperses.
Sixty-five kilograms may not sound like a lot in one of the biggest rivers in America. But it’s enough to account for 130,000 daily doses in the people peeing it out upstream in a giant watershed whose population isn’t much larger than that of metropolitan Sydney.
“Not much happens to it on its journey from person to sewage treatment plant to water,” Peterson said.
The chemical is known to be an endocrine disrupter in fish — meaning that among other things it can cause the feminization of male fathead minnows (Pimephales promelas, a freshwater species often used in lake and river studies). And while the levels in the ocean are lower than those studied in fresh water, the fact is that nobody has ever studied their effects. Is there a risk to fish?
“We don’t know,” Peterson said. “But it’s worth thinking about.”
Another problem is plastics. Big chunks of plastic, whether floating or washed ashore, are eyesores. But what really matters to environmental toxicologists are microplastics—bits ranging from microscopic to about five millimeters in size.
Most commonly, scientists have found, these take the form of fibers, such as strands from a fleece jacket which may have migrated from a washing machine to the ocean, via wastewater treatment plants no better designed to deal with this hazard than with pharmaceuticals.
But they can also come from the breakdown of polystyrene foam, which is used not only a packaging material, but also for flotation devices such as buoys designed to mark off oyster farming in parts of Asia.
Britta Baechler, another of Granek’s graduate students, is looking for microplastics in oysters and razor clams on the Oregon Coast. In the meantime, Baechler encourages people to be conscientious consumers.
This story originally appeared in COSMOS on 2-15-18. The above is an edited and shortened version. Story was reprinted with author's permission.