What’s tossed around, comes around
Ihad business near Woodville recently that led to my driving back roads in the area around dawn and dusk for a couple of weeks. The gently rolling hills along the route are mostly pastures, with cows and horses, and wildflowers grow in fallow fields, which made this an enjoyable drive.
Along the way each morning, I also spotted an array of wildlife — foxes, cottontails, bucks in velvet and does with spotted fawns and wild-turkey families. The high humidity and heat during those trips trapped moisture in the dawn air, so as I drove into the rising sun, its light lit the molecules from behind, lending a soft, misty glow to the already lovely, bucolic scene. At least it was lovely until discovered something on the road on morning — a large, plastic take-out cup.
Stopping to pick up the cup to dispose of it properly, I noticed “Super Big Gulp” and the 7-Eleven logo emblazoned on it. Not far from it, on the shoulder, were a Styrofoam food container and a ginger-ale bottle, both also empty. The condition and proximity of the three items, and the fact that I had seen none of them when I drove down the road the evening before, made me think they were all detritus from the same meal.
Here in Rappahannock County, we are lucky (and respectful) enough to mostly escape the trash that’s often strewn along suburban and urban roads. We also have some dedicated volunteers who clear trash along the main repository for it, U.S. 211, every spring. While I have occasionally seen some trash that might have escaped through an open window, or fallen off a truck through carelessness on the way to the dump, I doubt that this particular collection from 7-Eleven escaped on its own.
I can never quite understand how anyone can have such a blatant disregard not only for the natural beauty of our county but also for the impact of litter on our environment. What are these people thinking (I often wonder) that they can’t be bothered to properly dispose of their trash? Or are they rebels without a clue, lamely defying common decency and the littering laws?
One thing I’m pretty sure of is that they are clueless when it comes to the impact on ecosystems of trash, particularly plastics and other petroleum-based products. Evidence is growing that plastics do break down in the environment, but very slowly, and in the process become tiny particles, called microplastics, that can cause harm to wildlife, and may be hazardous to us humans. Much of this plastic ends up in our streams, mostly washed there by storms, which then take it to the Chesapeake Bay and, ultimately, our oceans, but that’s not the end of them.
As I wrote about in my Feb. 17 column, researchers have discovered that oysters can ingest tiny plastic particles, or microplastics. Ending up in the oysters’ guts, microplastics were shown to lower the oysters’ reproduction through disrupting their digestion or their hormone systems. Females made fewer eggs and males made slower sperm, resulting in fewer offspring, which mature more slowly.
Other aquatic wildlife species are also threatened by the increasing amount of plastics in our water. A study (tinyurl.com/wi-perchplastic) featured in the June 2 issue of the journal Science found that plastic particles from polystyrene (from which Styrofoam is made) interfere with several normal functions of the European perch ( Perca fluviatilis). Scientists raised the perch in water filled with the particles, in amounts matching the average and highest concentrations found along the Swedish coast, and found that 15 percent fewer of the perch hatched out than perch raised in clean water.
The fish from the plastics-polluted water that did manage to hatch out grew more slowly and “had bellies full of the plastic particles” after two weeks. The particles also appeared to blunt a normal instinct in this species — remaining still when they smell injured perch, to avoid being seen by predators. The upshot of the study: “These dramatic effects may be contributing to perch population declines in the Baltic Sea, and could cut short the lives of fish worldwide.”
On land, earthworms are also consuming microplastics from plant litter, according to a recent study (tinyurl.com/wi-earthworms2) on the effect of polyethylene
microplastics in plant litter on the nightcrawler ( Lumbricus terrestris), published in the journal Environmental Science and Technology. Researchers Esperanza Huerta Lwanga and her colleagues found that earthworms ingesting these microscopic particles had a “significantly reduced” rate of growth and higher mortality.
This invasive species of earthworm, from the United Kingdom, and other nonnative earthworms, present their own dangers to our ecosystems, but all these earthworms are important in the diets of many wildlife species, including robins, woodcocks and salamanders. This means the microplastics earthworms ingest are being introduced into the larger food web, which we humans are part of. According to the study, the worms also spread microplastics through their castings (excrement), which in turn can leach into streams, polluting them as well.
Anyone who thinks it’s too much trouble to dispose of trash properly might want to consider how difficult it will be to get tiny bits of it out of the food web. What we thoughtlessly throw into our ecosystems may come back to haunt us, according to a U.S. Environmental Protection Agency report (tinyurl.com/ wi-epa-trash):
“The ever-increasing volume of trash, litter, and debris entering inland waterways, coastal waters, and oceans presents a challenge to water quality and habitat protection that warrants attention. Trash has become a pervasive problem in these environments, causing aesthetic blight, ecological effects, economic impacts, and possible human health risks. . . . There is a growing concern about the potential for microplastic particles (plastic trash broken into smaller pieces) and their associated toxic chemicals to contribute to human health risks as the microplastics and toxics move through the marine food web.”
© 2016 Pam Owen