We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
From freshwaters to bivalves: Microplastic distribution along the Saint-Lawrence river-to-sea continuum
AI summary Read the abstract
Researchers traced microplastic distribution along the Saint-Lawrence River-to-sea continuum, finding both large and small microplastics in surface water and marine bivalves, with concentrations and polymer types varying between freshwater and estuarine environments.
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 and marine bivalve samples were collected along the river-to-sea continuum. The water samples were subdivided to characterize the large microplastics (LMPs; 300-3200 µm) and the small microplastics (SMPs; 20-300 µm). Particles were identified by microscopy and infrared spectroscopy techniques. The concentration of LMPs was higher in the surface water in the downstream stations (0.0319 ± 0.0147 items.L) compared to the upstream stations (0.0007 ± 0.0006 items.L). No clear trend was observed for the SMPs. After digestion of the biological tissues, the microplastics ingested by the bivalves were recovered and characterized by microscopy coupled with infrared spectroscopy. Up to 3 items were found per bivalve suggesting that these particles are also present in the water column of the marine estuary and the gulf. The physico-chemical gradients along the continuum were monitored since they could be directly involved in the vertical and horizontal transport of microplastics. This study provides scarce field data collected along the world's largest estuary and gives new insights concerning the fate of microplastics along a river-to-sea continuum.
More Papers Like This
The largest estuary on the planet is not spared from plastic pollution: Case of the St. Lawrence River Estuary
AI summary Read the abstract
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.
Distribution, abundance, and diversity of microplastics in the upper St. Lawrence River
AI summary Read the abstract
This study quantified the abundance, distribution, and diversity of microplastics in sediments of the St. Lawrence River, Canada, extending previous work on large polyethylene microbeads to a broader range of particle sizes and types. The results revealed widespread microplastic contamination across the river system, with urban areas showing the highest concentrations.
Spatial distribution and risk assessment of microplastics in surface waters of the St. Lawrence Estuary
AI summary Read the abstract
This study measured microplastic pollution in the St. Lawrence Estuary in eastern Canada, finding an average of 120 particles per cubic meter of surface water. Concentrations were highest near wastewater treatment plant outflows and agricultural areas. The research highlights that estuaries serve as major conduits for microplastic pollution moving from rivers to the ocean, affecting ecosystems and potentially the seafood that communities depend on.
Surface Water Microplastics in the St. Lawrence River and Estuary in Canada
AI summary Read the abstract
Researchers sampled the top 40 centimeters of surface water at 11 sites across the St. Lawrence River and Estuary in Canada, finding microplastics at every single site. Fibers were the most abundant type, followed by fragments, with polyester, polyethylene, polypropylene, nylon, and polystyrene the dominant materials. The study also observed that microplastics tended to aggregate more as water salinity increased toward the estuary mouth. The St. Lawrence is a major drinking water source and commercial fishery, making these baseline contamination data important for public health and ecosystem management.
Microplastic pollution in St. Lawrence River sediments
AI summary Read the abstract
Researchers found polyethylene microbeads in sediments of the St. Lawrence River at concentrations that increased downstream toward the heavily populated Quebec City area. The study is one of the first to document microplastics in the sediments of a major North American freshwater system and confirms that urban wastewater is a primary source.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.