Microplastic abundance and distribution in the open water and sediment of the Ottawa River, Canada, and its tributaries

Abstract

Microplastic pollution is prevalent in the Ottawa River, with all open water samples (n = 62) and sediment samples (n = 10) containing microplastics. The median microplastic concentration of nearshore 100 L water samples was 0. ), suggesting that the effluent plume is a pathway for plastic pollution to the Ottawa River. The mean concentration of microplastic fragments recovered in the sediment samples was 0.22 fragments per g dry weight. The abundance of microplastics in the sediment was not significantly related to the mean particle size or the organic content of the sediment. The most common form of plastic particles found was microfibers. These made up between 70% and 100% of all plastic particles observed, although plastic microbeads and secondary plastic fragments were also recovered.

Emerging threats and persistent conservation challenges for freshwater biodiversity

“…In some years, microplastic concentrations in the Danube River can outnumber planktonic larval fish concentrations (Lechner et al ., ). Microplastic pollutants vary among freshwater systems, but microfibres often comprise >75% of the plastic debris (Ballent et al ., ; Vermaire et al ., ). Derived from washing synthetic clothing (Browne et al ., ), the release of these microfibres is difficult to control in existing municipal wastewater treatment but filters on washing machines may be an option.…”

“…Better management of microplastic pollution in fresh waters requires a clearer understanding of: ( i ) sources, sinks and fluxes; ( ii ) factors controlling spatio‐temporal variations in microplastic concentrations; ( iii ) data on co‐transported contaminants; and ( iv ) routes of uptake and effects on freshwater organisms (Wagner et al ., ). Legislation to control microbeads has been implemented in several countries (United States: Microbead‐Free Waters Act, ; Canada: Microbeads in Toiletries Regulations, ), but these typically represent only a small fraction of the total plastic pollution (Ballent et al ., ; Vermaire et al ., ). As plastic production and consumption increase without better control, plastic concentrations in fresh waters are likely to rise.…”

“…Derived from washing synthetic clothing (Browne et al ., ), the release of these microfibres is difficult to control in existing municipal wastewater treatment but filters on washing machines may be an option. Microplastics are also deposited in aquatic sediments and benthic habitats (Castañeda et al ., ; Ballent et al ., ; Vermaire et al ., ), exposing benthic organisms.…”

Fate of Environmental Pollutants

“…Authors also estimated the annual emission of polyester and cotton microfibers from household washing machines as 154,000 (1.0 x 10 14 ) and 411,000 kg (4.9 x 10 14 ) in Finland (population 5.5 x 10 6 ). Vermaire et al (2017) found microplastic concentrations to be significantly higher downstream of the wastewater treatment plant (1.99 fragments per m 3 ) compared with upstream of the effluent output (0.71 fragments per m 3 ),…”

"As It Flows Down from the North": Confluences of Water Stewardship Emerging from the Ottawa River Watershed

“…It is useful to refer toHastrup's ideas again here. The Riverwatcher's work in localized areas such as Portagedu-Fort and Lower Allumette Lake in Westmeath where Meadows and St. Amour live and test water configures confluences of possible human imagination and interest(Hastrup 2014: 21) necessary to steward water amidst emerging threats, or "new bad guys" like microplastics, as Meadows put it during the morning we converged to carry outVermaire's (2017) microplastics sampling. These confluences, however episodic they may be or gradual in their impact, begin to configure a new relationship between people and the water they depend on and enable people to "fashion their life according to their understanding of water's course and force"(Hastrup 2014: 03).…”