Two forage fishes as potential conduits for the vertical transfer of microfibres in Northeastern Pacific Ocean food webs

We assessed the potential role played by two vital Northeastern Pacific Ocean forage fishes, the Pacific sand lance (Ammodytes personatus) and Pacific herring (Clupea pallasii), as conduits for the vertical transfer of microfibres in food webs. We quantified the number of microfibres found in the stomachs of 734 sand lance and 205 herring that had been captured by an abundant seabird, the rhinoceros auklet (Cerorhinca monocerata). Sampling took place on six widely-dispersed breeding colonies in British Columbia, Canada, and Washington State, USA, over one to eight years. The North Pacific Ocean is a global hotspot for pollution, yet few sand lance (1.5%) or herring (2.0%) had ingested microfibres. In addition, there was no systematic relationship between the prevalence of microplastics in the fish stomachs vs. in waters around three of our study colonies (measured in an earlier study). Sampling at a single site (Protection Island, WA) in a single year (2016) yielded most (sand lance) or all (herring) of the microfibres recovered over the 30 colony-years of sampling involved in this study, yet no microfibres had been recovered there, in either species, in the previous year. We thus found no evidence that sand lance and herring currently act as major food-web conduits for microfibres along British Columbia’s outer coast, nor that the local at-sea density of plastic necessarily determines how much plastic enters marine food webs via zooplanktivores. Extensive urban development around the Salish Sea probably explains the elevated microfibre loads in fishes collected on Protection Island, but we cannot account for the between-year variation. Nonetheless, the existence of such marked interannual variation indicates the importance of measuring year-to-year variation in microfibre pollution both at sea and in marine biota.

J. M. Hipfner, M. Galbraith, S. Tucker and al., Environmental Pollution, Volume 239, August 2018, Pages 215-222

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Microplastics and polycyclic aromatic hydrocarbons (PAHs) in Xiamen coastal areas: Implications for anthropogenic impacts

Microplastics and polycyclic aromatic hydrocarbons (PAHs) were investigated to study the influence of human activities and to find their possible relationship on the coastal environments, where the coastal areas around Xiamen are undergoing intensive processes of industrialization and urbanization in the southeast China. The abundance of microplastics in Xiamen coastal areas was 103 to 2017 particles/m3 in surface seawater and 76 to 333 particles/kg in sediments. Concentrations of dissolved PAHs varied from 18.1 to 248 ng/L in surface seawater. The abundances of microplastics from the Western Harbor in surface seawater and sediments were higher than those from other areas. Foams were dominated in surface seawater samples, however, no foams were found in sediments samples. The microscope selection and FTIR analysis suggested that polyethylene (PE) and polypropylene (PP) were dominant microplastics. The cluster analysis results demonstrated that fibers and granules had the similar sources, and films had considerably correlation with all types of PAHs (3 or 4-ring PAHs and alkylated PAHs). Plastic film mulch from agriculture practice might be a potential source of microplastics in study areas. Results of our study support that river runoff, watershed area, population and urbanization rate influence the distribution of microplastics in estuarine surface water, and the prevalence of microplastic pollution calls for monitoring microplastics at a national scale.

G. Tang, M. Liu, Q. Zhou and al., Science of The Total Environment, Volume 634, 1 September 2018, Pages 811-820

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Optimising beached litter monitoring protocols through aerial imagery

The monitoring of beached litter along the coast is an onerous obligation enshrined within a number of legislative frameworks (e.g. the MSFD) and which requires substantial human resources in the field. Through this study, we have optimised the protocol for the monitoring of the same litter along coastal stretches within an MPA in the Maltese Islands through aerial drones, with the aim of generating density maps for the beached litter, of assisting in the identification of the same litter and of mainstreaming this type of methodology within national and regional monitoring programmes for marine litter. Concurrent and concomitant in situ monitoring of beached litter enabled us to ground truth the aerial imagery results. Results were finally discussed within the context of current and future MSFD monitoring obligations, with considerations made on possible future policy implications.

A. Deidun, A. Gauci, S. Lagorio, F. Galgani, Marine Pollution Bulletin, Volume 131, Part A, June 2018, Pages 212–217

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Human footprint in the abyss: 30 year records of deep-sea plastic debris

This study reports plastic debris pollution in the deep-sea based on the information from a recently developed database. The Global Oceanographic Data Center (GODAC) of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) launched the Deep-sea Debris Database for public use in March 2017. The database archives photographs and videos of debris that have been collected since 1983 by deep-sea submersibles and remotely operated vehicles. From the 5010 dives in the database, 3425 man-made debris items were counted. More than 33% of the debris was macro-plastic, of which 89% was single-use products, and these ratios increased to 52% and 92%, respectively, in areas deeper than 6000 m. The deepest record was a plastic bag at 10898 m in the Mariana Trench. Deep-sea organisms were observed in the 17% of plastic debris images, which include entanglement of plastic bags on chemosynthetic cold seep communities. Quantitative density analysis for the subset data in the western North Pacific showed plastic density ranging from 17 to 335 items km−2 at depths of 1092–5977 m. The data show that, in addition to resource exploitation and industrial development, the influence of land-based human activities has reached the deepest parts of the ocean in areas more than 1000 km from the mainland. Establishment of international frameworks on monitoring of deep-sea plastic pollution as an Essential Ocean Variable and a data sharing protocol are the keys to delivering scientific outcomes that are useful for the effective management of plastic pollution and the conservation of deep-sea ecosystems.

S. Chiba, H. Saito, R. Fletcher and al., Marine Policy, Available online 6 April 2018, In Press

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Ten inconvenient questions about plastics in the sea

This paper aims to investigate some of the hottest issues that concern the increasing presence of plastics in the sea. In an attempt to identify the main knowledge gaps and to suggest future research, we discuss priority topics on marine plastic pollution through ten thought-provoking questions on the current knowledge of multiple consequences of plastics on the marine ecosystem. Our investigation found that the majority of knowledge gaps include not only intrinsic aspects of plastics (e.g. quantification, typology, fate), but also biological, ecological and legislative implications (e.g. ingestion rate by wildlife, biomagnification across food webs, spread of alien species, consequences for human nutrition, mitigation measures). The current scenario shows that science is still far from assessing the real magnitude of the impact that plastics have on the sea. In particular, the transfer of plastics across marine trophic levels emerged as one of the most critical knowledge gaps. Current regulations seem not sufficient to tackle the massive release of plastics into the sea. Within this complex picture, a positive note is the ever-increasing public awareness. The release of plastics into the sea is certainly a serious environmental issue that can be effectively addressed only through the combined efforts of the three main stakeholders: ordinary citizens through more eco-friendly behaviours, scientists by filling knowledge gaps, and policymakers by passing conservation laws relying on prevention and scientific evidence.

Giuseppe Bonanno, Martina Orlando-Bonaca, Environmental Science & Policy, Volume 85, July 2018, Pages 146–154

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Abundance, composition, and distribution of microplastics larger than 20 μm in sand beaches of South Korea

To support microplastic management, the abundance, composition, and spatial distribution of microplastics on a national scale must be known. Hence, we studied the baseline level of microplastic pollution at 20 sandy beaches along the South Korean coast. All microplastic particles extracted from the sand samples were identified down to 20 μm in size using Fourier transform infrared spectroscopy. The abundances of large microplastics (L-MPs; 1–5 mm) and small microplastics (S-MPs; 0.02–1 mm) were in the range of 0–2088 n/m2 and 1400–62800 n/m2, respectively. Maximum microplastic abundance was in the size range of 100–150 μm, and particles smaller than 300 μm accounted for 81% of the total abundance. Expanded polystyrene (EPS) accounted for 95% of L-MPs, whereas S-MPs were predominantly composed of polyethylene (49%) and polypropylene (38%). The spatial distribution of L-MPs, excluding EPS, was significantly related to population, precipitation, proximity to a river mouth and abundance of macroplastic debris on beach. However, there were no relationships between S-MPs and other environmental and source-related factors, except for macroplastic debris and L-MPs excluding EPS. These results imply that S-MPs are mainly produced on beaches by weathering, whereas L-MPs other than EPS are mainly introduced from land-based sources and are also partly produced on beaches.

Soeun Eo, Sang Hee Hong, Young Kyoung Song and al., Environmental Pollution, Volume 238, July 2018, Pages 894-902

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Fighting ocean plastics at the source

Some 8 million metric tons of plastic escapes into the world’s oceans each year, most of it from countries in Southeast Asia, where plastics use has outpaced waste management infrastructure. The situation is approaching catastrophic proportions. Read on to learn how governments, companies, and other organizations are focusing on the region in the hope that stopping the flow of trash there will substantially decrease plastic pollution.

Alexander H. Tullo, C&EN New York City, C&EN, 2018, 96 (16), pp 28–34, April 16, 2018

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