PAME Work Plan

This report describes the results of a two year project called “Microlitter in sewage treatment systems – A Nordic perspective on waste water treatment plants as pathways for microscopic anthropogenic particles to marine systems” funded by the Marine Group (HAV) under the Nordic Council of Ministers in 2014–2015.

The aim of the project was to investigate the significance of effluent water from sewage treatment plants (STPs) as gateway for microliter and other microscopic anthropogenic particles (MAPs) to the marine and aquatic environment. Further, to investigate the occurrence of these par- ticles both in the biotic and abiotic compartment of the receptor. STPs from Sweden, Finland and Iceland with different sewage treatment meth- ods were included in the study. Different SPT treatments were chosen to investigate the importance of sewage treatments on microparticle reten- tion in STPs. The report describes the methods used, results from the STP investigation and the amount of particles found in seawater, sediment and marine organisms in the receptor. Further, the report suggests a harmo- nized definition on particle shape for analyses which is beneficial for the international scientific community in order to facilitate comparison be- tween studies.

This study presents sampling and analysis of sediments for microplastics. The sampling area covers large scale geographical areas on the Norwegian Continental Shelf (NCS). The samples have been collected as an extra task during the regional offshore sediment monitoring on the NCS on behalf of the Oil & Gas industry. This study had therefore not been initiated without the good will from Oil & Gas operators, especially Statoil and ConocoPhillips Norway, which allowed use of some additional time during field work to take these samples.

The Norwegian Environment Agency saw this as a good opportunity to acquire knowledge of microplastic abundances from the NCS and therefore funded the project.

The Norwegian Geotechnical Institute (NGI) has put in own effort, assisted through the Skattefunn system (Project 266408), the projects FANTOM (RCN, 231736/F20) and JPI Oceans WEATHER-MIC (RCN, Project Grant 257433/E40), for the development of the analytical protocols and execution of the analysis and reporting. Through a relatively short period they have managed to deliver all results. A special thanks to Prof. Hans Peter Arp, Heidi Knutsen, Emma Jane Wade and Arne Petersen for the cooperation and all the work they have put in. Also, a special thanks to Øyvind Lilleeng at NMBU (Norwegian University of Life Sciences) whose substantial contribution to this report was done in partial fulfilment of the Masters Project tentatively entitled “The presence of microplastics on the Norwegian Continental shelf and coast of Havana”.

Microplastics (particles <5 mm) pose a threat to the marine ecosystem that is disproportionate to their tiny size. They have been found in high numbers in sea water and sediments, and are interacting with organisms and the environment in a variety of ways. Recently their presence has been confirmed in Polar water, sediment, and sea ice. We review the recent literature on microplastic distribution and transport in marine environments, primarily in the Northern Hemisphere, summarize current understanding, identify gaps in understanding, and suggest future research priorities.

Experiments were carried out with different Baltic Sea zooplankton taxa to scan their potential to ingest plastics. Mysid shrimps, copepods, cladocerans, rotifers, polychaete larvae and ciliates were exposed to 10 mm fluorescent polystyrene microspheres. These experiments showed ingestion of microspheres in all taxa studied. The highest percentage of individuals with ingested spheres was found in pelagic polychaete larvae, Marenzelleria spp. Experiments with the copepod Eurytemora affinis and the mysid shrimp Neomysis integer showed egestion of microspheres within 12 h. Food web transfer experiments were done by offering zooplankton labelled with ingested microspheres to mysid shrimps. Microscopy observations of mysid intestine showed the presence of zooplankton prey and microspheres after 3 h incubation. This study shows for the first time the potential of plastic microparticle transfer via planktonic organisms from one trophic level (mesozooplankton) to a higher level (macrozooplankton). The impacts of plastic transfer and possible accumulation in the food web need further investigations.

Microplastics are widely spread in the environ- ment, which along with still increasing production have aroused concern of their impacts on environmental health. The objective of this study is to quantify the number and mass of two most common textile fibers discharged from sequential machine washings to sewers. The number and mass of microfibers released from polyester and cotton textiles in the first wash varied in the range 2.1 × 105 to 1.3 × 107 and 0.12 to 0.33% w/w, respectively. Amounts of released microfibers showed a decreasing trend in sequential washes. The annual emission of polyester and cotton microfibers from household washing machines was estimated to be 154,000 (1.0 × 1014) and 411,000 kg (4.9 × 1014) in Finland (population 5.5 × 106). Due to the high emission values and sorption capacities, the polyester and cotton microfibers may play an important role in the transport and fate of chemical pollutants in the aquatic environment.

We analyzed polybrominated diphenyl ethers (PBDEs) in abdominal adipose of oceanic seabirds (short- tailed shearwaters, Puffinus tenuirostris) collected in northern North Pacific Ocean. In 3 of 12 birds, we detected higher-brominated congeners (viz., BDE209 and BDE183), which are not present in the natural prey (pelagic fish) of the birds. The same compounds were present in plastic found in the stomachs of the 3 birds. These data suggested the transfer of plastic-derived chemicals from ingested plastics to the tis- sues of marine-based organisms.

Microplastics are a ubiquitous pollutant in our seas today and are known to have detrimental effects on a variety of organisms. Over the past decade numerous studies have documented microplastic ingestion by marine species with more recent investigations focussing on the secondary impacts of microplastic ingestion on ecosystem processes. However, few studies so far have examined microplastic ingestion by mesopelagic fish which are one of the most abundant pelagic groups in our oceans and through their vertical migrations are known to contribute significantly to the rapid transport of carbon and nutrients to the deep sea. Therefore, any ingestion of microplastics by mesopelagic fish may adversely affect this cycling and may aid in transport of microplastics from surface waters to the deep-sea benthos. In this study microplastics were extracted from mesopelagic fish under forensic conditions and analysed for polymer type utilising micro-Fourier Transform Infrared Spectroscopy (micro-FTIR) analysis. Fish specimens were collected from depth (300–600m) in a warm-core eddy located in the Northwest Atlantic, 1,200 km due west of Newfoundland during April and May 2015. In total, 233 fish gut contents from seven different species of mesopelagic fish were examined. An alkaline dissolution of organic materials from extracted stomach contents was performed and the solution filtered over a 0.7μm borosilicate filter. Filters were examined for microplastics and a subsample originating from 35 fish was further analysed for polymer type through micro-FTIR analysis. Seventy-three percent of all fish contained plastics in their gut contents with Gonostoma denudatum having the highest ingestion rate (100%) followed by Serrivomer beanii (93%) and Lampanyctus macdonaldi (75%). Overall, we found a much higher occurrence of microplastic fragments, mainly polyethylene fibres, in the gut contents of mesopelagic fish than previously reported. Stomach fullness, species and the depth at which fish were caught at, were found to have no effect on the amount of microplastics found in the gut contents. However, these plastics were similar to those sampled from the surface water. Additionally, using forensic techniques we were able to highlight that fibres are a real concern rather than an artefact of airborne contamination.