Monitoring of styrene oligomers as indicators of polystyrene plastic pollution in the North-West Pacific Ocean

Styrene oligomers (SOs) as global contaminants are an environmental concern. However, little is known on the distribution of SOs in the ocean. Here, we show the distribution of anthropogenic SOs generated from discarded polystyrene (PS) plastic monitored from the coastal ocean surface waters (horizontal distribution) and deep seawaters (vertical distribution) in the North-West Pacific Ocean. SOs concentrations in surface seawater and deep seawater ranged from 0.17 to 4.26 μg L−1 (total mean: 1.48 ± 1.23 μg L−1) and from 0.31 to 4.31 μg L−1 (total mean: 1.32 ± 0.87 μg L−1), respectively. Since there is no significant difference in the mean concentrations, SOs seems to be spread across marine environment selected in this study. Nevertheless, regional SOs appears to persist to varying degrees with their broad horizontal and vertical distribution in the ocean. Each horizontal and vertical distribution of SOs differs by approximately 1.95–2.57 times, probably depending on the events of weather and global ocean circulation. These results provide the distribution pattern of SOs for assessing environmental pollution arising from PS plastic.

Bum Gun Kwon, Keiji Amamiya, Hideto Sato and al., Chemosphere, Volume 180, August 2017, Pages 500–505

The article

Microplastics shedding from polyester fabrics

To minimize microplastics from polyester fabrics getting in the ocean, and posing a threat to the marine environment, the production design of polyester fabrics needs to change. Mistra Future Fashion now release new findings where their researchers and industry partners have investigated the relation between fabric properties and shedding for polyester fabrics, and thereby contribute to fill current research gap. (…) (Mistra Future Fashion, 15/06/2017)

The report

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

Plastic pollution in the Antarctic worse than expected

The continent is considered to be a pristine wilderness compared to other regions and was thought to be relatively free from plastic pollution. However new findings by scientists from University of Hull and British Antarctic Survey (BAS) have revealed that recorded levels of microplastics are five times higher than you would expect to find from local sources such as research stations and ships. (…) (bas.ac.uk, British Antarctic Survey, 19/06/2017)

The news

The study

Microplastics found in waters off Qatar

The first evidence of prevalence of microplastics in Gulf seawater, specifically in the marine waters off Qatar, has been documented through a research study conducted by senior researchers from Qatar University Environmental Science Center (QU-ESC).
“Polypropylene microplastics were the most common type of plastic polymer found with most particles being either granular or fibrous in shape, with sizes from 125?m to 15.98mm”, said team leader and ESC’s former director and professor Dr Jeff Obbard.
Such microplastics are commonly associated with general plastic packaging waste, and marine fishing nets. He noted that the levels of microplastics found in Qatar’s marine waters are still relatively low compared to some other locations around the world, but vigilance is needed. (…) (gulf-times.com, 19/06/2017)

The news

An estimation of the average residence times and onshore-offshore diffusivities of beached microplastics based on the population decay of tagged meso- and macrolitter

Residence times of microplastics were estimated based on the dependence of meso- and macrolitter residence times on their upward terminal velocities (UTVs) in the ocean obtained by one- and two-year mark-recapture experiments conducted on Wadahama Beach, Nii-jima Island, Japan. A significant linear relationship between the residence time and UTV was found in the velocity range of about 0.3–0.9 ms− 1, while there was no significant difference between the residence times obtained in the velocity range of about 0.9–1.4 ms− 1. This dependence on the UTV would reflect the uprush-backwash response of the target items to swash waves on the beach. By extrapolating the linear relationship down to the velocity range of microplastics, the residence times of microplastics and the 1D onshore-offshore diffusion coefficients were inferred, and are one to two orders of magnitude greater than the coefficients of the macroplastics.

Hirofumi Hinata, Keita Mori, Kazuki Ohno, Yasuyuki Miyao, Tomoya Kataoka, Marine Pollution Bulletin, Available online 16 June 2017, In Press

The article

Plastic ingestion in oceanic-stage loggerhead sea turtles (Caretta caretta) off the North Atlantic subtropical gyre

Juvenile oceanic-stage sea turtles are particularly vulnerable to the increasing quantity of plastic coming into the oceans. In this study, we analysed the gastrointestinal tracts of 24 juvenile oceanic-stage loggerheads (Caretta caretta) collected off the North Atlantic subtropical gyre, in the Azores region, a key feeding ground for juvenile loggerheads. Twenty individuals were found to have ingested marine debris (83%), composed exclusively of plastic items (primarily polyethylene and polypropylene) identified by μ-Fourier Transform Infrared Spectroscopy. Large microplastics (1–5 mm) represented 25% of the total number of debris and were found in 58% of the individuals sampled. Average number of items was 15.83 ± 6.09 (± SE) per individual, corresponding to a mean dry mass of 1.07 ± 0.41 g. The results of this study demonstrate that plastic pollution acts as another stressor for this critical life stage of loggerhead turtles in the North Atlantic.

Christopher K. Pham, Yasmina Rodríguez, Axelle Dauphin and al., Marine Pollution Bulletin, Available online 9 June 2017, In Press

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