The vertical distribution and biological transport of marine microplastics across the epipelagic and mesopelagic water column

Plastic waste has been documented in nearly all types of marine environments and has been found in species spanning all levels of marine food webs. Within these marine environments, deep pelagic waters encompass the largest ecosystems on Earth. We lack a comprehensive understanding of the concentrations, cycling, and fate of plastic waste in sub-surface waters, constraining our ability to implement effective, large-scale policy and conservation strategies. We used remotely operated vehicles and engineered purpose-built samplers to collect and examine the distribution of microplastics in the Monterey Bay pelagic ecosystem at water column depths ranging from 5 to 1000 m. Laser Raman spectroscopy was used to identify microplastic particles collected from throughout the deep pelagic water column, with the highest concentrations present at depths between 200 and 600 m. Examination of two abundant particle feeders in this ecosystem, pelagic red crabs (Pleuroncodes planipes) and giant larvaceans (Bathochordaeus stygius), showed that microplastic particles readily flow from the environment into coupled water column and seafloor food webs. Our findings suggest that one of the largest and currently underappreciated reservoirs of marine microplastics may be contained within the water column and animal communities of the deep sea.

C. Anela Choy, Bruce H. Robison, Tyler O. Gagne, Benjamin Erwin, Evan Firl, Rolf U. Halden, J. Andrew Hamilton, Kakani Katija, Susan E. Lisin, Charles Rolsky & Kyle S. Van Houtan, Scientific Reports, 9, Article number: 7843 (2019)

The article

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Tara repart à la chasse aux plastiques

La goélette scientifique Tara a remis les voiles, ce lundi 27 mai. Le navire a quitté le ponton de la Cité de la voile, à Lorient La Base, vers 10 h 30, sous le regard de quelques badauds. Tara entame sa 12e expédition, une mission de six mois à travers l’Europe, sur la piste des microplastiques. Initialement prévu ce jeudi 23 mai, le départ de Tara avait été différé de quelques jours, suite à un problème technique. À bord, cinq marins et dix scientifiques. (…)

« La mission Microplastiques 2019 va contribuer à la recherche fondamentale, comme l’ensemble des expéditions Tara, mais celle-ci comporte un enjeu sociétal fort, dont toutes les générations doivent s’emparer à présent pour changer notre rapport aux ressources, à leur préservation et, à très court terme, de changer de mode de consommation, de production », rappelle Romain Troublé, le directeur général de la fondation Tara Océan.

Mer et Marine, 28/05/2019

Prevalence of microplastic pollution in the Northwestern Pacific Ocean

Highlights

The microplastic pollution and its associated physical oceanographic parameters in the Northwestern Pacific were measured.

Microplastic characteristics, such as colors, sizes, shapes, chemical compositions, and surface morphology were evaluated.

The possible sources of microplastics were analyzed based on their characteristics.

The transport pathways of microplastics were proposed by wind and current, ARGOS drift trajectory, chemical composition.

Pan Z., Sun X., Guo H. and al., Chemosphere, Volume 225, June 2019, Pages 735-74

The article

Biodegradable bags can hold a full load of shopping three years after being discarded in the environment

Biodegradable plastic bags are still capable of carrying full loads of shopping after being exposed in the natural environment for three years, a new study shows.Researchers from the University of Plymouth examined the degradation of five plastic bag materials widely available from high street retailers in the UK.They were then left exposed to air, soil and sea, environments which they could potentially encounter if discarded as litter.The bags were monitored at regular intervals, and deterioration was considered in terms of visible loss in surface area and disintegration as well as assessments of more subtle changes in tensile strength, surface texture and chemical structure.After nine months in the open air, all the materials had completely disintegrated into fragments.However, the biodegradable, oxo-biodegradable and conventional plastic formulations remained functional as carrier bags after being in the soil or the marine environment for over three years. (University of Plymouth, Alan Williams,

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Evidence of transport of styrene oligomers originated from polystyrene plastic to oceans by runoff

This study demonstrates for the first time that styrene oligomers (SOs), which are indicators of polystyrene (PS) plastic contamination in the environment, are transported from land to the ocean. Samples of sand and seawater were taken from the coastline of the Tokyo Bay over the past four years, and all samples of both sand and seawater were found to contain SOs such as styrene monomer (SM), styrene dimers (SD), and styrene trimers (ST), with the concentration distributions of these being in the order of ST > SD > SM. The concentrations of these SOs are linearly proportional to monthly precipitation. These results indicate that various land-based SOs sources are connected with the estuary, a substantial amount of which are transported into Tokyo Bay through runoff as overland flow. As a result, runoff by precipitation is a potential transport pathway of land-based SOs sources. This finding is of interest in terms of both the extent of PS plastic pollution and the transport of SOs to the ocean.

Amamiya K., Saido K., Chung S. Y. and al., Science of The Total Environment, Volume 667, 1 June 2019, Pages 57-63

The article

Solving Plastic pollution through accountability

The global plastics pollution crisis will only worsen unless all actors across the plastics value chain are made more accountable for the true cost of plastics to nature and people, warns a WWF report published today. The new study, Solving Plastic Pollution Through Accountability, finds that too much responsibility for reducing plastics pollution is currently focused on consumers and waste management and efforts will remain insufficient unless action is taken across the entire value chain.The report, released ahead of a key United Nations Environment Assembly (UNEA) meeting in Nairobi next week, warns that an additional 104 million metric tons of plastic is at risk of leakage to our ecosystems by 2030 without a drastic change in approach.The leakage caused by this broken system is having devastating effects on wildlife and ecosystems. More than 270 species have been documented as having been harmed by entanglement, while more than 240 species have been found to have ingested plastics. Every year humans and animals continue to ingest plastics from food and drinking water, with the full effects still unknown.According to the report, under a business as usual scenario, the overall CO2 emissions from the plastic life cycle are expected to increase by 50%, while the CO2 increase from plastic incineration is set to triple by 2030, due to wrong waste management choices.

The report WWF, 2019

Microplastic-mediated transport of PCBs? A depuration study with Daphnia magna

The role of microplastic (MP) as a carrier of persistent organic pollutants (POPs) to aquatic organisms has been a topic of debate. However, the reverse POP transport can occur if relative contaminant concentrations are higher in the organism than in the microplastic. We evaluated the effect of microplastic on the PCB removal in planktonic animals by exposing the cladoceran Daphnia magna with a high body burden of polychlorinated biphenyls (PCB 18, 40, 128 and 209) to a mixture of microplastic and algae; daphnids exposed to only algae served as the control. As the endpoints, we used PCB body burden, growth, fecundity and elemental composition (%C and %N) of the daphnids. In the daphnids fed with microplastic, PCB 209 was removed more efficiently, while there was no difference for any other congeners and ΣPCBs between the microplastic-exposed and control animals. Also, higher size-specific egg production in the animals carrying PCB and receiving food mixed with microplastics was observed. However, the effects of the microplastic exposure on fecundity were of low biological significance, because the PCB body burden and the microplastic exposure concentrations were greatly exceeding environmentally relevant concentrations.

Zandra Gerdes , Martin Ogonowski, Inna Nybom, Caroline Ek, Margaretha Adolfsson-Erici, Andreas Barth, Elena Gorokhova, PLoS ONE 14(2): e0205378, 2019

The article