Our beloved Laurentian Great Lakes, which make up roughly one fifth of the world’s fresh surface water and support 1000s of species of wildlife, have become contaminated by our plastic waste. In fact, researchers estimate that roughly 10,000 tonnes of plastics enter the Great Lakes every year, polluting all five of our Great Lakes and their surrounding watersheds. Each year, approximately one million pieces of plastic litter are collected by community scientists as part of the International Coastal Cleanup, which includes the Great Canadian Shoreline Cleanup. And that’s not all (!) – beyond what the eye can see are tiny pieces of plastics called microplastics (<5 mm in size - as large as your pinky nail or as small as the width of a strand of your hair). Microplastics are found in surface water, sediment and in wildlife within and around the Great Lakes, reaching as high as 1.25 million particles/km2 – a concentration on par with what is found in the ocean’s garbage patches – in surface waters. Even our drinking water, despite water treatment, has been shown to contain plastic particles.
Plastic picked up as part of the International Coastal Cleanup for years 2016 – 2018. Figure made by Arielle Earn from U of T Trash Team.
Plastic debris, of all types, shapes and sizes, enter our lakes from various sources (e.g., litter from land, debris from vessels, tire dust in road runoff, pellets from industry, or microfibers from washing our clothing entering via wastewater treatment plants). Understanding these sources is a key part of the solution.
The Great Lakes Plastic Cleanup will capture plastic litter from our Great Lakes and remove it. In addition, we will also capture DATA! Our large network of community scientists, spread across the Great Lakes, will be measuring how much we collect by mass, and also characterizing the litter by product type (e.g., straw, pre-production pellet, foam take-out container) and material (e.g., plastic, metal, paper). Combined, this data will allow us to understand the effectiveness of our network in removing plastic litter, and allow us to make predictions about the sources of litter entering our waterways. For example, if we find a lot of plastic pellets in the bins, we may link this to plastic industry upstream. If we see many plastic straws and food wrappers, we may attribute the material to the littering of single-use plastic items. This information will inform policy-makers about effective solutions to prevent litter, including both upstream and downstream.