Ingestion of microplastic debris by green sea turtles (Chelonia mydas) in the Great Barrier Reef: Validation of a sequential extraction protocol

Ocean contamination by plastics is a global issue. Although ingestion of plastic debris by sea turtles has been widely documented, contamination by microplastics (< 5 mm) is poorly known and likely to be under-reported. We developed a microplastic extraction protocol for examining green turtle (Chelonia mydas) chyme, which is multifarious in nature, by modifying and combining pre-established methods used to separate microplastics from organic matter and sediments. This protocol consists of visual inspection, nitric acid digestion, emulsification of residual fat, density separation, and chemical identification by Fourier transform infrared spectroscopy. This protocol enables the extraction of polyethylene, high-density polyethylene, (aminoethyl) polystyrene, polypropylene, and polyvinyl chloride microplastics > 100 μm. Two macroplastics and seven microplastics (two plastic paint chips and five synthetic fabric particles) were isolated from subsamples of two green turtles. Our results highlight the need for more research towards understanding the impact of microplastics on these threatened marine reptiles.

A. Caron, C. Thomas, K. Berry and al., Marine Pollution Bulletin, Volume 127, February 2018, Pages 743–751

The article

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Threat of plastic ageing in marine environment. Adsorption/desorption of micropollutants

Ageing of various plastics in marine environment was monitored after immersion of two synthetic (polyvinylchloride, PVC, and polyethylene terephthalate, PET) and one biodegradable (poly(butylene adipate co-terephtalate), PBAT) plastics for 502 days in the bay of Lorient (Brittany, France). Data analysis indicates that aged PVC rapidly releases estrogenic compounds in seawater with a later adsorption of heavy metals; PET undergoes a low weakening of the surface whereas no estrogenic activity is detected; PBAT ages faster in marine environment than PVC. Aged PBAT exhibits heterogeneous surface with some cavities likely containing clay minerals from the chlorite group. Besides, this degraded material occasionally shows a high estrogenic activity. Overall, this study reports, for the first time, that some aged plastics, without being cytotoxic, can release estrogenic compounds in marine environment.

Mikaël Kedzierski, Mélanie D’Almeida, Anthony Magueresse and al., Marine Pollution Bulletin, Volume 127, February 2018, Pages 684-694

The article

Proceedings of the International Conference on Microplastic Pollution in the Mediterranean Sea

This book focuses on different aspects of microplastic pollution, offering authors and readers the opportunity to share their knowledge, identify issues and propose solutions and actions to face this environmental threat. Although plastic pollution is a well-known global problem, the recent discovery of microplastics and nanoplastics in seas and oceans represents a very alarming new environmental challenge. The book offers comprehensive insights into the origins of the problem, its impact on marine environments, particularly the Mediterranean Sea and coasts, and the current research trends aimed at finding technical solutions to mitigate the phenomenon.

Part of the Springer Water book series (SPWA). Editors : Mariacristina Cocca, Emilia Di Pace, Maria Emanuela Errico, Gennaro Gentile, Alessio Montarsolo, Raffaella Mossotti, 2018

The book

Microplastic and tar pollution on three Canary Islands beaches: An annual study

Marine debris accumulation was analyzed from three exposed beaches of the Canary Islands (Lambra, Famara and Las Canteras). Large microplastics (1–5 mm), mesoplastics (5–25 mm) and tar pollution were assessed twice a month for a year. There was great spatial and temporal variability in the Canary Island coastal pollution. Seasonal patterns differed at each location, marine debris concentration depended mainly of local-scale wind and wave conditions. The most polluted beach was Lambra, a remote beach infrequently visited. The types of debris found were mainly preproduction resin pellets, plastic fragments and tar, evidencing that pollution was not of local origin, but it cames from the open sea. The levels of pollution were similar to those of highly industrialized and contaminated regions. This study corroborates that the Canary Islands are an area of accumulation of microplastics and tar rafted from the North Atlantic Ocean by the southward flowing Canary Current.

A. Herrera, M. Asensio, I. Martínez, A. Santana, T. Packard, M. Gómez, Marine Pollution Bulletin, Available online 6 November 2017, In Press

The article

Are we underestimating microplastic contamination in aquatic environments?

Plastic debris, specifically microplastic in the aquatic environment, is an escalating environmental crisis. Efforts at national scales to reduce or ban microplastics in personal care products are starting to pay off, but this will not affect those materials already in the environment or those that result from unregulated products and materials. To better inform future microplastic research and mitigation efforts this study (1) evaluates methods currently used to quantify microplastics in the environment and (2) characterizes the concentration and size distribution of microplastics in a variety of products. In this study, 50 published aquatic surveys were reviewed and they demonstrated that most (~80%) only account for plastics ≥ 300 μm in diameter. In addition, we surveyed 770 personal care products to determine the occurrence, concentration and size distribution of polyethylene microbeads. Particle concentrations ranged from 1.9 to 71.9 mg g−1 of product or 1649 to 31,266 particles g−1 of product. The large majority ( > 95%) of particles in products surveyed were less than the 300 μm minimum diameter, indicating that previous environmental surveys could be underestimating microplastic contamination. To account for smaller particles as well as microfibers from synthetic textiles, we strongly recommend that future surveys consider methods that materials < 300 μm in diameter.

Jeremy L. Conkle, Christian D. Báez Del Valle, Jeffrey W. Turner, Environmental Management, Environmental Management, , Volume 61, Issue 1, pp 1–8

The article

Spatial variability in the concentrations of metals in beached microplastics

Heavy metals and microplastics have been considered as threats to the marine environment and the interactions between these two pollutants are poorly understood. This study investigates the interactions between metals adsorbed in pellets collected randomly from 19 beaches along the coast of São Paulo State in southeastern Brazil, comparing these levels with those in virgin pellets. The samples were analyzed for Al, Cr, Cu, Fe, Mn, Sn, Ti and Zn by inductively coupled plasma optical emission spectroscopy (ICP-OES). The polymers were solubilized via acid digestion. The highest levels occurred with Fe (227.78 mg kg− 1 – Itaguaré) and Al (45.27 mg kg− 1 – Guaraú) in the same areas, which are closer to the Port of Santos. The metal adsorption on pellets collected is greater than that on virgin pellets. In this context, pellets can be considered to be a carrier for the transport of metals in the environment, even in small quantities.

M.C. Vedolin, C.Y.S. Teophilo, A. Turra, R.C.L. Figueira, Marine Pollution Bulletin, Available online 13 October 2017, In Press

The article

Marine litter at the seafloor – Abundance and composition in the North Sea and the Baltic Sea

Litter is present in all marine waters around the globe. It consists of several compound classes of which plastic is of special interest because of its high abundance and possible threat to marine organisms. The regional distribution, composition and abundance of large litter items (LI) at the sea floor of the North Sea and the Baltic Sea were investigated based on 175 bottom trawls between 2013 and 2015. Different types of marine litter > 2.5 cm were classified according to the protocol of the ICES International Bottom Trawl Survey. The results showed considerable geographical variation: In the North Sea, a mean litter abundance of 16.8 LI/km2 was found, whereas the litter abundance in the Baltic Sea was significantly lower (5.07 LI/km2). In general, plastic represented 80% of the litter items. During the study, some methodical aspects with possible impact on the results were identified that need to be addressed in future sampling campaigns.

Ulrike Kammann, Marc-Oliver Aust, Horst Bahl, Thomas Lang, Marine Pollution Bulletin, Available online 12 October 2017, In Press

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