John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
Scientists monitoring Lake Erie have found tons of harmful plastic debris known as microplastics or "nurdles."
When people swim in Lake Erie, they're frolicking not just among perch and walleye but a vast, inanimate presence of garbage. This material floats just beneath the surface and is made of little bits of plastic, known as microplastics or "mermaids' tears," which come from trash dropped by humans and probably industrial facilities around the lake as well.
Oceanographers have been aware of plastic-particle water pollution since at least the 1960s. It got great public billing in the '80s when NOAA informed us of a vast zone of plastic debris coursing through the Pacific Ocean. The so-called Great Pacific Garbage Patch (or "Trash Vortex," if you prefer) has popped up in observers' reports between Hawaii and California and off the coast of Japan; some say it's twice the size of Texas, although the true extent is unknown. Researchers are just now beginning to understand that lakes are plastic garbage dumps, too, and ones that could hold much denser concentrations of debris than the oceans.
Lorena Rios-Mendoza, an oceanographer at the University of Wisconsin-Superior, is one of the scientists who've plunged the polluted depths of American lakes. Her team recently sampled sections of Lake Erie – which can't seem to catch a break these days, what with its mercury infection and rashes of poisonous algae – and discovered that the water's been invaded by great quantities of microplastics mostly smaller than grains of rice. Specifically, they measured concentrations between 1,500 and 1.7 million particles per square mile, which is 24 percent greater than what they found in the Atlantic Ocean's debris field.
The thriving plastics colony represents a significant hazard to biodiversity, because the small chunks look like food to fish, birds and other creatures. Once they're swallowed, the indigestible material can fill up an animal's stomach and create a fatal blockage. Or it might give the critters a false feeling of satiation, causing them to starve to death.
The microplastics are also magnificent sponges for hazardous chemicals like PCBs, accumulating from 100,000 to a million times of the now-banned substance than what's normally in the water, according to NOAA. That's concerning because we don't really know if the chemicals leach from the plastic into the fish that eat them – and potentially into humans that eat the fish. It's clear that Lake Erie's fish are eating the plastic, the researchers say:
Fish and birds could be harmed from accidentally eating the plastic particles, or absorbing substances that leach out into the water, Rios said. Her team knows from analyses of fish stomachs that fish are consuming the plastic particles....
"The main problem with these plastic sizes is its accessibility to freshwater organisms that can be easily confused as natural food and the total surface area for adsorption of toxins and pseudo-estrogens increases significantly," Rios said.
This survey comes on the heels of another effort by researchers at the State University of New York, who found that Erie was the most debris-ridden of the Great Lakes. (Lesser-populated areas around Superior and Huron had less plastic pollution.) One of the scientists in that project noted that the material seems custom-built to stay off the public's radar: “People became aware of plastics in the oceans and waters in the ‘60s and ‘70s, and the great Pacific garbage patch. But from far away, bits of plastic look just like the water. So it’s not so noticeable or recognized in the greater topic of plastics in the environment.”
So where's this stuff coming from? In some cases, it's created by larger plastic goods like bottles, food containers, toys and auto-body parts. In the ocean plastic doesn't biodegrade, it just splits up into tinier and tinier pieces until it's nearly invisible to humans. Even biodegradable bags and bottles have trouble breaking down when submerged in water.
Manufacturing processes also create a significant portion of the world's microplastics. Little orbs of plastic known as nurdles are a widely used building material for finished commercial products. The tiny beads escape into the environment during their manufacturing or transport and are ferried by wind and rain into the ocean – or sometimes they're just spilled into the sea, as was the case near Hong Kong when a ship went into distress during 2012's Typhoon Vicente:
It's likely that people will start taking more interest in the issue as our water sources slowly become sludgy with microplastics. That could happen sooner rather than later: Since 1980, the beginning of the decade when the Trash Vortex hit the news, worldwide plastics production has increased by more than 500 percent, according to an industry group. At one point in the '90s researchers estimated there were over 100 million nurdles on the beaches of California's Orange County alone. It would seem the Day of the Nurdle is nigh.
Top photo of microplastics courtesy of NOAA