Microplastic distribution along a Saint-Lawrence river-to-sea continuum (2019)

Despite the close connection of freshwaters to human health, the occurrence and fate of microplastics in marine estuaries remain poorly documented. To study these particles in the Saint-Lawrence River (Quebec, Canada), surface water samples were collected along a river-to-sea continuum, from Saint-Louis Lake to Cacouna. The microplastics from these water samples were isolated and sorted by size range and by shapes: fibers (1 dimension), films (2 dimensions) or fragments (3 dimensions). Particles were identified by microscopy and infrared spectroscopy techniques. The physico-chemical (temperature, conductivity, pH and dissolved oxygen) gradients along the continuum were monitored at the time of sampling. Sampling of microplastics (0.3 – 3.2 mm) in surface water was carried out using an original pumping system (without plastic), at the rate of 3 replicates of 1,000 L per station.

This work provides the first set of data concerning the microplastic pollution in a major river-to-sea continuum of North America and describes the fate of these microplastics along horizontal physico-chemical gradients.

For more information you can consult the scientific article which results from these data:

• L. Rowenczyk, H. Cai, B. Nguyen, M. Sirois, M.-C. Côté-Laurin, N. Toupoint, A. Ismail, N. Tufenkji, From freshwaters to bivalves: Microplastic distribution along the Saint-Lawrence river-to-sea continuum, Journal of Hazardous Materials, Volume 435, 2022,128977, ISSN 0304-3894, https://doi.org/10.1016/j.jhazmat.2022.128977.