Waterloo scientists find disturbingly little about plastics in the Great Lakes

Tuesday, March 24, 2015

Recent coverage about the pygmy sperm whale that died in Halifax Harbour with a belly full of plastic is a sad reminder of the growing amount of plastic litter found in the oceans. Unfortunately, plastic debris may be an equal if not greater environmental problem for the Great Lakes.

We know more and more about ocean plastics, but, paradoxically, we have little information on the distribution and fate of plastic debris in the Great Lakes, the world’s largest freshwater resource,” says Philippe Van Cappellen, Canada Excellence Research Chair and professor of Earth and Environmental Sciences in the Faculty of Science.

Canada Excellence Research Chair Philippe Van CappellenA review article by Van Cappellen and fellow researchers from Waterloo’s Ecohydrology Research Group appears as an open source publication in this month’s issue of Journal of Great Lakes Research.

It combines surveys from university research studies and ground-based observations by volunteer beach clean-up groups to yield the first comprehensive assessment of the plastics problem in the Great Lakes.

Plastic debris is not just an unsightly accumulation of plastic litter on beaches. It threatens the environment and poses hazards to our fishing, shipping and tourism industries, and perhaps even human health.

Many plastics take thousands of years to completely degrade. Meanwhile, they break down through mechanical abrasion into smaller pieces that persist in the environment. These microplastics act like sponges for certain pollutants and are easily ingested by aquatic organisms, including fish and shellfish, which may ultimately end up on our plates.   

Survey any stream or river in the Great Lakes region and there is a good chance you will find plastic debris, including microplastics,” says first author Alex Driedger, a graduate student in the Ecohydrology Research Group.

Plastics can range enormously in size from large drums and cigarette filters to microscopic plastic beads found in facial scrubs and body washes, and plastic fibres washed from synthetic clothing in everyday laundry.

Microplastic particles flushed down the drain are so tiny they end up bypassing wastewater treatment. Microbeads have been found in water released from six out of seven wastewater treatment plants in New York State. Neither Canadian nor American wastewater treatment plants are required to monitor plastics in their discharge, so the true extent of plastics loading is currently unknown.

In 2012, volunteer beach clean-up groups reported that between 77 and 90 per cent of litter found on Great Lakes beaches consisted of plastics. The most commonly reported plastic debris on beaches were cigarette filters, followed by plastic food wrappers and containers. 

Lake Erie has the highest concentration of plastic debris among all the Great Lakes – higher even than Lake Geneva, which has more than three times the surrounding population density. In fact, results show that certain areas of the Great Lakes have suspended plastics concentrations as high as those found in the so-called garbage patches accumulating within large oceanic gyres.

Canada needs to step up to the plate and take action,” says Van Cappellen, who is also a member of the Water Institute. “Both the Europeans and Americans are proposing legislation to deal with the problem. Canada should follow their lead.”

The Canada Excellence Research Chair program funded the research. Earth and Environmental Sciences Professor Hans Dürr and former postdoctoral fellow Kristen Mitchell co-authored the paper. Mitchell is currently a William L. Fisher US Congressional Geoscience Fellow in Washington DC.

Science in mediaThis story has appeared in the following news outlets: 

  • CBC News, "Plastic microbeads: small bits with a big impact"
  • CBC The Current, "Pressure mounts to label microbeads as toxic substances in Canada"
  • CBC KW, "Are microbeads a big problem?"
  • Michigan Radio, "Researchers work to understand how our plastic waste affects the Great Lakes"