Microbeads have attracted a lot of public and political attention in the Great Lakes region since Sam Mason and her lab first discovered the tiny beads in staggering numbers in lakes Huron, Superior, and Erie in 2012. Since then, sampling excursions on the remaining lakes—conducted with help from Illinois-Indiana Sea Grant and 5 Gyres—have turned up similar findings.
In many ways, the results of these studies raise more questions than they ask. One of the most important, though, is “What effect do microbeads and other plastic pollutants have on Great Lakes food webs and ecosystems?” Research into this question has only just begun, but years of studies in the oceans provide some insight. Some of these latest findings come from our friends at South Carolina Sea Grant.
From Coastal Heritage:
John Weinstein is studying how grass shrimp (Palaemonetes pugio) respond to a diet of plastic beads. A crustacean about the size of half of a shelled peanut, a grass shrimp consumes microalgae that grow on plant detritus—especially decomposing saltmarsh stems called “wrack”—along estuaries and coasts, but it’s also a predator on a wide variety of small animals.
Because of its abundance, sensitivity, and ecological importance in southeastern U.S. estuaries, the grass shrimp is often used to study the effects of pollution in the field and laboratory.
In Weinstein’s lab, Austin Gray, a graduate student in biology at The Citadel, has been feeding grass shrimp two types of beads: one a bright green and the other one translucent.
The green beads are polyethylene, the type of plastic used in plastic bags, bottles, plastic wrap and other films for food preservation, and many other products. Polyethylene is the most common type of plastic found in marine debris around the world.
The translucent beads are polypropylene, a type of plastic used in bottle caps, candy- or chip-wrappers, and food containers. Polypropylene is the second most common type of plastic found in marine debris.
In a lab dish, Austin Gray deposits translucent 75-micron beads. But a visitor looks in the dish and can’t find a single bead. Under the dissecting microscope, though, dozens of tiny spheres suddenly appear. To put it in perspective, an item at about 40 microns is the width of two spooning human hairs.
Gray fed 16 grass shrimp a diet of brine shrimp mixed in with plastic beads. Each grass shrimp was isolated in water that was changed every other day. Eight animals were fed polyethylene beads and eight were fed polypropylene beads. After six days, all of the 16 shrimp were dead.
Dissecting the animals, Gray found plastic beads in their guts and gills. One individual had 10 tiny beads in its gut and 16 in its gills.
The gut blockages, though, were deadlier. The grass shrimp could still take in water through their partly blocked gills. But they stopped eating with clogged guts—or couldn’t eat—and died.
“In my mind,” says Weinstein, “it’s consistent with starvation. The more particles in guts, the more quickly the grass shrimp die.
Concern about results like these has led Illinois to become the first state to ban the sale of microbeads in personal care products. The law, passed in June, is slated to take full effect in 2019. Similar legislation has also been considered in New York and California.
Click on the link above to read the full article.
***Photo: Collecting plastic samples in southern Lake Michigan in 2013.
It has been nearly one year since IISG set sail on Lake Michigan to sample for plastic pollution. Since then, Sam Mason, a chemist from State University of New York Fredonia, and her research team have been hard at work analyzing those water samples. The initial results are revealed in the latest edition of IISG’s interview series UpClose.
In this issue, Mason talks about her ongoing work to quantify plastic pollution in the Great Lakes for the first time. In addition to the Lake Michigan results, Mason discusses plastic levels in the other four lakes, explains how plastics could impact aquatic wildlife, and suggests additional research needed to understand this emerging contaminant.
This is the sixth edition of UpClose, which takes readers behind the scenes of the latest research on pharmaceuticals and personal care products. Each interview targets a different component of PPCP research—everything from what happens to pharmaceuticals when water is treated to what bacterial resistance could mean for other aquatic wildlife living in urban rivers. Readers also get an insider’s view of the complex, and sometimes tricky, process of conducting field studies, and the potential implications of research on industries and regulations.
Read previous issues of UpClose at unwantedmeds.org. For print copies, contact Pollution Prevention Program Specialist Laura Kammin.
IISG’s Laura Kammin and Anjanette Riley set sail today on a mission to find plastics in Lake Michigan. The trip is a part of a larger effort to determine if the plastics and microplastics that have been found in the world’s oceans are an issue in the Great Lakes too. Sampling kicked off last year with research trips on Lakes Huron, Superior, and Erie, and the findings came as a bit of a surprise – millions of tiny plastic particles floating in the water in even higher concentrations than in the Great Pacific Garbage Patch.
The first round of sampling revealed that the Lakes are home to between 1,500 and 1.7 million plastic particles per square mile, with Lake Erie housing the largest concentrations. Dr. Sherri “Sam” Mason of the State University of New York (SUNY) at Fredonia, Dr. Lorena Rios-Mendoza of University of Wisconsin, and Dr. Marcus Erikson of 5 Gyres Institute have determined that much of the plastic they found was actually microbeads, found in many brands of toothpaste and facial and body scrubs. These tiny pieces of plastic are less than a millimeter in diameter, much too small to be filtered out by wastewater treatment facilities before that water is released into nearby lakes and rivers.
Anjanette and Laura, along with researchers from SUNY at Fredonia and 5 Gyres Institute, are on Lake Michigan this week to see how the plastic load there compares to the other Great lakes. The crew will collect approximately 20 samples between now and August 10 as they zigzag their way across southern Lake Michigan. Dr. Mason will process the samples in the coming months. The research team also plans to extend the project to Lake Ontario and get a second round of samples from Lake Erie later this summer.
A recent study of several Great Lakes has revealed a high concentration of plastic pollution – higher levels than any other water body on the planet, according to the findings.
“The study is the first to look at plastic pollutants in the Great Lakes. It is part of a larger global endeavor to understand the origin and prevalence of plastic pollution in water and was conducted with the Los Angeles-based 5 Gyres Institute.
“We had two samples in Lake Erie that we just kept going back and rechecking the data, because the count, the number of plastic particles in the sample, was three times greater than any sample collected anywhere in the entire world,” SUNY chemistry professor and project lead Sherri Mason said.”
Follow the link above for the complete article, which offers additional information about the types of plastic pollution and the plans for additional study.
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