Ingestion of plastic fragments by the Guri sea catfish Genidens genidens (Cuvier, 1829) in a subtropical coastal estuarine system

One of the most recognized anthropogenic impacts in marine environments is solid waste pollution, especially plastic, which can be ingested by fish, thus interfering with their health. In this context, the aim of this study is to describe the ingestion of plastic fragments and to identify the possible effect of this contamination in the condition factor of Genidens genidens in the Laguna Estuarine System. The stomach contents of 92 G. genidens (26 juveniles and 66 adults) were analyzed. The Index of Relative Importance was performed to identify the contribution of each prey item. Condition factor (CF) was used to analyze the effect of plastic ingestion on the fish’s body condition (by comparing individuals in the same ontogenetic phase). For the juveniles, eight items were observed, the most important of which were Penaeidae, followed by Portunidae and plastic. For the adults, 12 items were observed, the most important of which were Penaeidae, Portunidae, Polychaeta, and plastic. The analysis of CF demonstrated higher values for individuals without plastic in the stomach, which indicated a better health condition. The CF of a fish may be affected by variations in the physiological condition, environmental stresses, and nutritional and biological variations, and could be used to compare the body condition or health of a fish species. The ingestion of plastic could significantly influence the worst body condition of the individuals that were analyzed in the present study. The plastic pollution in marine coastal waters is associated with the appropriate waste management levels.

David V. Dantas, Cristian I. R. Ribeiro, Catarina de C. A. Frischknecht, Rodrigo Machado, Eduardo G. G. Farias, Environmental Science and Pollution Research, pp 1–8, 2019

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Presence of microplastics in the stomachs of Carcinus aestuarii Nardo, 1857 in Çardak Lagoon, Çanakkale Strait, Turkey

This paper reports the presence of microplastic in the stomachs of the Mediterranean green crab, Carcinus aestuarii Nardo, 1857. The crabs were collected from six sites chosen in the Çardak Lagoon (Çanakkale Strait). Plastic fibers were observed in the stomach contents of three male individuals. Since C. aestuarii is an important food for fish and birds in estuarine and lagoon areas, microplastics can go up to the trophic levels by entering the food chain.

, Cah. Biol. Mar. (2018) 59 : 493 – 496

The article

Floating matter: a neglected component of the ecological integrity of rivers

Floating matter (FM) is a pivotal, albeit neglected, element along river corridors contributing to their ecological integrity. FM consists of particulate matter of natural (e.g. wood, branches, leaves, seeds) and anthropogenic (e.g. plastic, human waste) origin as well as of organisms that, due to its properties, is able to float on the water surface. In this paper, we provide a comprehensive overview of the FM cycle and the fundamental environmental functions FM provides along rivers. Indeed, FM serves as an important geomorphological agent, a dispersal vector for animals and plant propagules, a habitat, a resource, and a biogeochemical component. Furthermore, we collected data on the amount of FM accumulating at dams and in reservoirs, and related it to key characteristics of the respective catchments. River fragmentation truncates the natural dynamics of FM through its extraction at damming structures, alteration in the flow regime, and low morphological complexity, which may decrease FM retention. Finally, we identify key knowledge gaps in relation to the role FM plays in supporting river integrity, and briefly discuss FM management strategies.

O. Shumilova, K. Tockner, A. M. Gurnell, S. D. Langhans, M. Righetti, A. Lucía, C. Zarfl, Aquatic Sciences, , 81:25

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Transfer of PCBs from microplastics under simulated gut fluid conditions is biphasic and reversible

The role of plastic as a vector for bioaccumulation of toxic chemicals is central to the risk assessment of microplastic for human health and the environment. However, transfer kinetics of sorbed contaminants from ingested microplastics are poorly understood. We develop and parameterise a chemical exchange model on microplastics in a gut fluid mimic of aquatic biota, and also included food to provide a better representation of contaminant dynamics when plastic and food are ingested, as would occur in nature. The transfer kinetics of 14 polychlorinated biphenyls (PCBs) were measured in gut fluid mimic systems under three environmentally relevant exposure scenarios of plastic ingestion by organisms, for low-density polyethylene (LDPE) and polyvinyl chloride (PVC), and were evaluated with the model. Chemical transfer was demonstrated to be biphasic and fully reversible, with fast exchange within hours followed by a slow transfer lasting for weeks to months. In clean gut systems, the bioavailability of plastic-associated PCBs for lugworms and cod ranged from 14-42% and 45-83% respectively. However, in contaminated gut systems, clean microplastic was capable of rapidly extracting (‘cleaning’) PCBs from food inside the gut, thus demonstrating that the effect of microplastic is context dependent. Therefore, chemical contamination and cleaning are likely to occur simultaneously due to the ingestion of microplastic.

Nur Hazimah Mohamed Nor and Albert A. Koelmans, Environ. Sci. Technol., Just Accepted Manuscript, January 14, 2019

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Small microplastics as a main contributor to plastic mass balance in the North Atlantic subtropical gyre

Estimates of cumulative plastic inputs into the oceans are expressed in hundred million tons, whereas the total mass of microplastics afloat at sea is three orders of magnitude below this. This large gap is evidence of our ignorance about the fate of plastics, as well as transformations and sinks in the oceans. One of the current challenges consists of identifying and quantifying plastic particles at the microscale, the small microplastics (SMP, 25-1000 µm). The aim of the present study is to investigate SMP count and mass density at the sea surface in the North Atlantic subtropical gyre during the sea campaign Expedition 7th Continent. After isolation, SMP were characterized by micro-Fourier-transform infrared spectroscopy. Microplastic distribution was modeled by a wind-driven vertical mixing correction model taking into account individual particle properties (dimension, shape and density). We demonstrate that SMP buoyancy is significantly decreased compared to the large microplastics (LMP, 1-5 mm) and consequently more susceptible to vertical transport. The uncorrected LMP count density was between 13 000 and 174 000 pieces km-2, and was between 5 to 170 times more abundant for SMP. With a wind-driven vertical mixing correction, we estimated that SMP were 300 to 70 000 times more abundant than LMP. When discussing this in terms of weight after correction, LMP densities were between 50 to 1 000 g km-2, and SMP densities were between 5 and 14 000 g km-2.

Marie POULAIN, Matthieu J Mercier, Laurent Brach, Marion Martignac, Corinne Routaboul, Emile Perez, Marie Christine Desjean, and Alexandra ter Halle, Environ. Sci. Technol., Just Accepted Manuscript, December 21, 2018

Microplastics contaminate the deepest part of the world’s ocean

Millions of metric tons of plastics are produced annually and transported from land to the oceans. Finding the fate of the plastic debris will help define the impacts of plastic pollution in the ocean. Here, we report the abundances of microplastic in the deepest part of the world’s ocean. We found that microplastic abundances in hadal bottom waters range from 2.06 to 13.51 pieces per litre, several times higher than those in open ocean subsurface water. Moreover, microplastic abundances in hadal sediments of the Mariana Trench vary from 200 to 2200 pieces per litre, distinctly higher than those in most deep sea sediments. These results suggest that manmade plastics have contaminated the most remote and deepest places on the planet. The hadal zone is likely one of the largest sinks for microplastic debris on Earth, with unknown but potentially damaging impacts on this fragile ecosystem.

X. Peng, M. Chen, S. Chen and al., Geochemical Perspectives Letters v9, Published 27 November 2018

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Composition and abundance of benthic marine litter in a coastal area of the central Mediterranean Sea

Abundance and qualitative composition of benthic marine litter were investigated in a coastal area of the central Mediterranean Sea. Almost 30 km of video footage, collected by a Remotely Operated Vehicle between 5 and 30 m depth, were analyzed. Litter density ranged from 0 to 0.64 items/m2 with a mean of 0.11 (±0.16) items/m2. General wastes, made up almost entirely of plastic objects, were the dominant sources of debris representing 68% of the overall litter. The remaining 32% consisted of lost or abandoned fishing gears. Synthetic polymers, considering both fishing gears and general waste, represented 73% of total debris items. Our results are comparable with litter amounts reported in other Mediterranean sites at similar depths. Overall, the results are discussed in terms of monitoring strategy, to support the implementation of the Marine Strategy Framework Directive (2008/56/EC) for descriptor 10 and the Mediterranean UN Environment (UNEP/MAP) regional Plan on Marine Litter.

P. Consoli, M. Falautano, M. Sinopoli and al., Marine Pollution Bulletin, Volume 136, November 2018, Pages 243-247

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