Plastic pollution in freshwater ecosystems: macro-, meso-, and microplastic debris in a floodplain lake

Plastic pollution is considered an important environmental problem by the United Nations Environment Programme, and it is identified, alongside climate change, as an emerging issue that might affect biological diversity and human health. However, despite research efforts investigating plastics in oceans, relatively little studies have focused on freshwater systems. The aim of this study was to estimate the spatial distribution, types, and characteristics of macro-, meso-, and microplastic fragments in shoreline sediments of a freshwater lake. Food wrappers (mainly polypropylene and polystyrene), bags (high- and low-density polyethylene), bottles (polyethylene terephthalate), and disposable Styrofoam food containers (expanded polystyrene) were the dominant macroplastics recorded in this study. Contrary to other studies, herein macroplastic item surveys would not serve as surrogates for microplastic items. This is disadvantageous since macroplastic surveys are relatively easier to conduct. Otherwise, an average of 25 mesoplastics (mainly expanded polystyrene) and 704 microplastic particles (diverse resins) were recorded per square meter in sandy sediments. Comparisons with other studies from freshwater and marine beaches indicated similar relevance of plastic contamination, demonstrating for the first time that plastic pollution is a serious problem in the Paraná floodplain lakes. This study is also valuable from a social/educational point of view, since plastic waste has been ignored in the Paraná catchment as a pollutant problem, and therefore, the outcome of the current study is a relevant contribution for decision makers.

Martin C. M. Blettler, Maria Alicia Ulla, Ana Pia Rabuffetti, Nicolás Garello, Environmental Monitoring and Assessment, , 189:581,

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Ingestion of microplastics by freshwater Tubifex worms

Microplastic contamination of the aquatic environment is a global issue. Microplastics can be ingested by organisms leading to negative physiological impacts. The ingestion of microplastics by freshwater invertebrates has not been reported outside the laboratory. Here we demonstrate the ingestion of microplastic particles by Tubifex tubifex in a major urban waterbody fed by the River Irwell, Manchester, UK. The host sediments had microplastic concentrations ranging from 56 to 2544 particles kg-1. 87% of the Tubifex ingested microplastic particles were microfibres (55 – 4100 µm in length), whilst the remaining 13% were fragments (50 – 4500 µm in length). FT-IR analysis revealed ingestion of a range of polymers, including polyethylene terephthalate (polyester) and acrylic fibres. Whilst microbeads were present in the host sediment matrix, they were not detected in Tubifex worm tissue. However, there was limited selectivity in the ingestion of microplastics within the fragment or fiber subtypes. The mean concentration of ingested microplastics was 129 ± 65.4 particles g-1 tissue. We also show that Tubifex worms retain microplastics longer than other components of the ingested sediment matrix. Microplastic ingestion by Tubifex worms poses a significant risk for trophic transfer and biomagnification of microplastics up the aquatic food chain.

Rachel R Hurley, Jamie C Woodward, and James J. Rothwell, Environ. Sci. Technol., Just Accepted Manuscript, October 11, 2017

Microplastics – a review of existing knowledge

CEH ecotoxicologist, Alice Horton, delivered a lecture entitled ‘Microplastics – what we know?’ at the CIWEM Priority Substances and Micro-Pollutants in London on September 14, 2017.

In this recording, Alice provides a primer on microplastics, then reviews existing knowledge regarding the key sources of microplastics through to environmental fate and associated ecological and human health impacts. She also provides a background to UK policy.

She then explores microplastics within freshwater environments, her specific research area, and identifies the key research questions that should be investigated. (CEH, 19/09/2017)

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Mountains to the sea: River study of plastic and non-plastic microfiber pollution in the northeast USA

Aquatic environments are sinks for anthropogenic contamination, whether chemical or solid pollutants. Microfibers shed from clothing and other textiles contribute to this problem. These can be plastic or non-plastic origin. Our aim was to investigate the presence and distribution of both types of anthropogenic microfibers along the length of the Hudson River, USA. Surface grab samples were collected and filtered through a 0.45 μm filter paper. Abundance of fibers was determined after subtraction of potential contamination. 233 microfibers were recorded in 142 samples, averaging 0.98 microfibers L− 1. Subsequent micro-FTIR showed half of the fibers were plastic while the other half were non-plastic, but of anthropogenic origin. There was no relationship between fiber abundance, wastewater treatment plant location or population density. Extrapolating from this data, and using available hydrographic data, 34.4% of the Hudson River’s watershed drainage area contributes an average 300 million anthropogenic microfibers into the Atlantic Ocean per day.

R. Miller, A. J. R. Watts, B. O. Winslow and al., Marine Pollution Bulletin, Volume 124, Issue 1, 15 November 2017, Pages 245-251

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Occurrence of phthalate acid esters (PAEs) in the northwestern Mediterranean Sea and the Rhone River

Phthalate acid esters (PAEs) which are mainly anthropogenic molecules with endocrine disrupting effects in animals and humans, have been detected in terrestrial and aquatic environments. However, little is known about their distribution in the Mediterranean Sea, mainly because of analytical difficulties and the high possibility of ambient sample contamination. Here, we report the optimization of an existing protocol for the determination of PAEs in seawater and freshwater samples, as well as the first estimation of the source and distribution of phthalates acid esters (PAEs) in coastal waters from the NW Mediterranean Sea. By passing 1 L of sample through glass cartridges packed with 200 mg of Oasis HLB and eluted with 6 mL of ethyl acetate, the recoveries for DMP, DEP, DPP, DiBP, DnBP, BzBP, DEHP and DnOP were 101, 98, 115, 110, 99, 98, 103 and 95%, respectively, with acceptable blank values (below 0.4-4.0% of the masses measured in different seawater samples). By using this method, we detected PAEs in the Marseilles coastal area, offshore (2000 m depth) and in the Rhone River with total concentrations ranging from 75.3 ng/L offshore in surface water to 1207.1 ng/L a few meters above the bottom of the Marseilles Bay. High concentrations were also observed in deep waters offshore (310.2 ng/L) as well as in the Rhone River (615.1 ng/L). These results suggest that Marseilles urban area, Rhone River and sediment are potential sources of PAEs in the areas studied.

Andrea Paluselli, Yann Aminot, François Galgani, Sopheak Net, Richard Sempéré, Progress in Oceanography, Available online 21 June 2017, In Press

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Ingestion of micro- and nanoplastics in Daphnia magna – Quantification of body burdens and assessment of feeding rates and reproduction

Evidence is increasing that micro- and nanoplastic particles can have adverse effects on aquatic organisms. Exposure studies have so far mainly been qualitative since quantitative measurements of particle ingestion are analytically challenging. The aim of this study was therefore to use a quantitative approach for determining ingestion and egestion of micro- and nanoplastics in Daphnia magna and to analyze the influence of particle size, exposure duration and the presence of food. One week old animals were exposed to 2 μm and 100 nm fluorescent polystyrene beads (1 mg/l) for 24 h, followed by a 24 h egestion period in clean medium. During both phases body burdens of particles were determined by measuring the fluorescence intensity in dissolved tissues. Ingestion and egestion were investigated in the absence and presence of food (6.7·105 cells of Raphidocelis subcapitata per ml). Furthermore, feeding rates of daphnids in response to particle exposure were measured as well as effects on reproduction during a 21 days exposure (at 1 mg/l, 0.5 mg/l and 0.1 mg/l) to investigate potential impairments of physiology. Both particle sizes were readily ingested, but the ingested mass of particles was five times higher for the 2 μm particles than for the 100 nm particles. Complete egestion did not occur within 24 h but generally higher amounts of the 2 μm particles were egested. Animal body burdens of particles were strongly reduced in the presence of food. Daphnid feeding rates decreased by 21% in the presence of 100 nm particles, but no effect on reproduction was found despite high body burdens of particles at the end of 21 days exposure. The lower egestion and decreased feeding rates, caused by the 100 nm particles, could indicate that particles in the nanometer size range are potentially more hazardous to D. magna compared to larger particle sizes.

Sinja Rist, Anders Baun, Nanna B. Hartmann, Environmental Pollution, Volume 228, September 2017, Pages 398–407

Microplastics in gut contents of coastal freshwater fish from Río de la Plata estuary

The presence of microplastics (MPs) in gut contents of coastal freshwater fish of the Rio de la Plata estuary was studied. Samples were taken in six sites where 87 fish belonging to 11 species and four feeding habits were captured. Presence of MPs was verified in the 100% of fish. The fibres represented the 96% of MPs found. The number of MPs in gut contents was significantly higher close to sewage discharge. There was not found relationship between number of MPs and fish length, weight or feeding habit. The spatial differences in mean number of MPs in fish observed in this study, suggest that environmental availability of MPs could be of great importance to explain the differences found among sampling sites analysed. This work represents the first study about the interaction between MPs and aquatic organisms in this important estuarine ecosystem of South America.

Rocío S. Pazos, Tomás Maiztegui, Darío C. Colautti and al., Marine Pollution Bulletin, Vol. 122 (1-2), 15 September 2017

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