Community Scientists Have New EPA Guidelines for Sampling Microplastic Pollution. How Useful Are They?
Scientists have found microplastics in nearly every kind of aquatic ecosystem, from rivers and lakes down to the depths of the ocean. Now, new federal guidelines show how anyone interested in undertaking their own community science experiment can investigate their waterways — but their results may not perfectly represent what’s lurking underwater.
Community scientists can use these guidelines for sandy beaches or shorelines of oceans, bays, lakes and rivers, but a scientist who examined the protocol told EcoWatch it might not be appropriate for rocky beaches.
You might already have everything you need in your basement or shed, but most items can likely be easily borrowed or purchased at a local hardware store, like wooden stakes, a five-gallon bucket, rope, tweezers and a really long tape measure. The protocol, issued by the U.S. Environmental Protection Agency (EPA), lists fifteen basic items you’ll need to acquire, in addition to a downloadable marine debris tracking app to which the agency recommends uploading collected data.
The guidelines detail how to arrange a large sampling area into quadrats, or frames, that you’ll randomly select for further search. Essentially, within those frames, you’ll want to remove any large, obviously natural debris, like seaweed, shells or driftwood.
But first, you’ll want to brush off any microplastics attached to those items (the protocol provides advice about particularly difficult to brush off items, like seaweed clumps) and use the suggested equipment to filter, collect and sort it.
But the conclusions that community scientists can draw from their experiment are limited. Microplastics by their very nature are miniscule, so even the use of a magnifying glass isn’t enough to see everything. And the one-millimeter strainer that the protocol requires is too porous to capture most microplastics, according to one scientist.
“Now, most of the micro plastics are so small they will go through that [sieve], so they won’t be collected,” explained Judith Weis, whose research as a professor emerita at Rutgers University in Newark, New Jersey, includes environmental contaminants. “So this kind of [process] is collecting the larger microplastics and missing the small ones and the most abundant ones.”
The protocol acknowledges that because “microplastics smaller than [one millimeter] in size (such as microbeads) are more difficult to find… more sophisticated technology is required to conclusively identify them,” likely beyond the access of most interested community members.
EPA communications staff did not return a request for comment related to the data collection effort, including limitations of community scientists only being able to report microplastics above a certain size. Nevertheless, Weis says that the collected data, imperfect though it may be, still is generally useful.
“If that collection shows a whole lot more at one place than another place, that’s useful information,” she explained. “If that kind of data shows that at one place now there is a lot less [microplastic] than five years from now, that’s useful information… and if you see a big difference from one place to another, that’s valid.”
But, she continued, “You shouldn’t be under the illusion that you’re getting an accurate count of the different kinds of shapes and the amounts because there’s all the stuff that will be smaller or long and thin and go through.”