Washington — Plastics in the ocean and birds with resin pellets in their bellies may attract the headlines, but it was the science behind microplastics in the Great Lakes that drew some pointed attention at a recent Congressional hearing.
A Sept. 19 House appropriations subcommittee hearing on marine debris turned into a 90-minute crash course on plastics and marine science, with lawmakers probing where government science should go and looking at new areas, like how plastic marine debris is emerging as a new way for invasive species to travel the globe.
Lawmakers representing states bordering the Great Lakes — states that are heavy with plastics product manufacturing — noted what one legislator called "increasing public concern" around plastics in the environment.
Rep. Dave Joyce, R-Ohio, said he was "startled" by testimony about microfibers and microplastics in fish, and he quizzed scientists on what it might mean for food supplies.
"The science is showing that microplastics enter the food web and eventually make their way into the food we eat," said Joyce, whose district borders Lake Erie. "We are only beginning to understand the extent of the issue and its implications for human health.
"Plastics are one of the most pervasive types of marine debris and are drawing increasing public concern," he said. Joyce is the ranking Republican on the subcommittee.
As well, the chair of the subcommittee, Rep. Betty McCollum, D-Minn., called for more scientific work around measuring microplastics. She also noted Great Lakes-related concerns, along with broader coastal concerns, and urged more focus on reducing single-use plastics.
In her opening comments, McCollum noted the "vital" role of plastics in health care, food safety, transportation and other areas. But she said she was disturbed by research showing how "pervasive" microplastics were in the environment, from the peaks of the Rocky Mountains to Arctic ice flows.
Marine debris cleanup in general and plastics in particular are a rising cost to taxpayers, she argued at several points in the hearing.
"We as a subcommittee need to get serious about doing what we can to point out to the American public that we're paying for this," McCollum said. "We need to be wise as consumers and taxpayers to do what we can to reduce the use of these one-time plastics."
The hearing was not called to advance new legislation. Rather, the oversight panel gathered to hear from government agencies under its jurisdiction, like the Department of the Interior, and from other scientists on what government agencies are doing and what else they should do.
A lot of the lawmakers' focus was on plastics, especially in new areas of science.
Under questioning from Joyce, for example, Chelsea Rochman, an assistant professor at the University of Toronto and a science adviser to the Ocean Conservancy, noted that her work has found microfibers and microplastics in Lake Ontario fish, sometimes with more than 100 pieces in a fish.
She said she began her research on microplastics in the ocean but later included the Great Lakes.
"Coming from starting my research in the middle of the ocean, the amount of microplastics in the Great Lakes is striking," Rochman said. She testified that the Great Lakes do not dilute particles the way the oceans do, potentially making microplastics more concentrated.
Most of that microplastic in fish is found in the guts, which people generally do not eat, and researchers are trying to determine if it migrates into the parts of the fish that people do eat, she said.
The evidence is mixed, she said, with one study finding little or no migration in rainbow trout. But there's not a lot of research, Rochman said.
In his opening remarks, Joyce cited research that found 22 million pounds of plastic enters the Great Lakes each year.
"As the largest freshwater system on earth and a source of drinking water for millions, the volume of debris in the Great Lakes is alarming," he said.
