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The largest estuary on the planet is not spared from plastic pollution: Case of the St. Lawrence River Estuary

Marine Pollution Bulletin 2024 3 citations

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Researchers conducted the first macroplastic survey along the St. Lawrence Estuary shorelines, finding ubiquitous contamination dominated by single-use polypropylene, polyethylene, and polystyrene items at an average density of 0.17 items/m², with abundance declining with distance from the Montreal metropolitan area.

Study Type Environmental

The St. Lawrence River, one of the world's largest estuaries, drains >25 % of the world's freshwater reserves and is affected by various anthropogenic effluents. Although previous studies reported micro- and nanoplastics contamination in the Estuary and Gulf of St. Lawrence (EGSL), this study provides a first evaluation of macroplastic pollution along the north and south shores of the EGSL. Plastic debris categorization was performed according to the OSPAR protocol completed by polymer identification using Fourier-transform infrared spectroscopy. The EGSL appeared ubiquitously contaminated by plastic debris, dominated by single-use plastics primarily made of polypropylene (28 %), polyethylene (25 %) and polystyrene (17 %). The EGSL shores exhibited a mean contamination level of 0.17 ± 0.11 items/m and distance to Montreal significantly influenced the distribution of plastic debris. This study provides an essential baseline for implementing local waste reduction and management actions in the St. Lawrence watershed to reduce plastic pollution.

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