Marine litter disrupts ecological processes in reef systems

Marine litter (ML) contaminates essentially all global coastal and marine environments and drives multiple ecosystem-level effects. Although deleterious effects of ML on several organisms have been investigated in the last years, this information tends to be dispersed or underreported, even in marine biodiversity hotspots such as reef ecosystems. Two are the main goals of this paper: (i) to integrate and synthesize current knowledge on the interactions of ML and reef organisms, and (ii) to evaluate the multiple disruptions on the ecological processes in reef systems. We report here ML-driven ecological disruptions on 418 species across eight reef taxa, including interactions that were previously not addressed in detail, and evaluate their major conservation implications. These results can help raise awareness of global impacts on the world’s reefs by highlighting ML associations in different reef systems around the world, and can aid in ML input reduction and marine management.

Gustavo F. de Carvalho-Souza, Marcos Llope, Moacir S. Tinôco, Diego V. Medeiros, Rodrigo Maia-Nogueira, Cláudio L.S. Sampaio, Marine Pollution Bulletin, Volume 133, August 2018, Pages 464–471

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Microplastics on the Portuguese coast

Marine anthropogenic litter was analysed in eleven beaches along the Portuguese coast, over a two-year period (2011−2013). Of all collected items, 99% were plastic and 68% were microplastics (MP; 1–5 mm in diameter). Higher MP concentrations were found in winter/autumn, near industrial areas and/or port facilities and in beaches exposed to dominant winds. Resin pellets (79%) were the dominant category close to industrial areas and high concentrations of fragments and polymeric foams were found near fishing ports. The most frequent pellet size classes were 4 and 5 mm (respectively 47% and 42%). Results suggest that MP have predominately a land-based origin and are deliberately discarded or accidentally lost in watercourses and/or coastal areas. A combination of measures within stakeholders, namely industry and fishing sectors and share of good practices are needed to prevent marine anthropogenic litter.

J. Antunes, J. Frias, P. Sobral, Marine Pollution Bulletin, Volume 131, Part A, June 2018, Pages 294-302

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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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Application of an enzyme digestion method reveals microlitter in Mytilus trossulus at a wastewater discharge area

The ingestion of microlitter by blue mussels (450) was studied at a wastewater recipient area in the Baltic Sea. The mussel soft tissues were digested using enzymatic detergents and the detected litter particles characterized with FT-IR imaging spectroscopy. Microlitter concentration in seawater and WWTP effluent were also measured. Microlitter was found in 66% of the mussels. Mussels from the WWTP recipient had higher microlitter content compared to those collected at the reference site. Plastics made up 8% of all the analysed microlitter particles. The dominating litter types were fibres (~90% of all microlitter), 42% of which were cotton, 17% linen, 17% viscose and 4% polyester. The risk of airborne contamination during laboratory work was lowered when mussels were digested with their shells on instead of dissecting them first. The approach was found applicable and gentle to both non-synthetic and synthetic materials including fragile fibres.

Saana Railo, Julia Talvitie, Outi Setälä and al., Marine Pollution Bulletin, Volume 130, May 2018,  Pages 206–214

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Is the microplastic selective according to the habitat? Records in amphioxus sands, Mäerl bed habitats and Cymodocea nodosa habitats

This study estimated for the first time the total loads of plastic litter (macro- meso- and micro-plastics) in sediments of different habitat types from the Northern Adriatic Sea. Samples were collected in March 2016. The sampling sites were settled in shoreline, on the C. nodosa bottoms, Amphioxus sands, and Mäerl bed habitats. Microplastics items were present in all sampling site and ranging within 137-703 items/kg d.w. from Mäerl bed habitat to the shoreline. In C. nodosa bottoms 170 items/kg d.w. were found, while in Amphioxus sands were recorded on average 194 items/kg d.w. Due to the absence of statistical associations among litter levels and abundance of B. lanceolatum in the study area, this research present the needs to develop a new method and more research to for the evaluation of how much the interrelation between sensible habitats and microplastic exist.

M. Renzi, A. Blašković, P. Fastelli and al., Marine Pollution Bulletin, Volume 130, May 2018, Pages 179-183

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Virgin microplastics are not causing imminent harm to fish after dietary exposure

Among aquatic organisms, fish are particularly susceptible to ingesting microplastic particles due to their attractive coloration, buoyancy, and resemblance to food. However, in previous experimental setups, fish were usually exposed to unrealistically high concentrations of microplastics, or the microplastics were deliberately contaminated with persistent organic chemicals; also, in many experiments, the fish were exposed only during the larval stages. The present study investigated the effects of virgin microplastics in gilt-head seabream (Sparus aurata) after 45 days’ exposure at 0.1 g kg−1 bodyweight day−1 to 6 common types of microplastics. The overall growth, biochemical analyses of the blood, histopathology, and the potential of the microplastics to accumulate in gastrointestinal organs or translocate to the liver and muscles were monitored and recorded. The results revealed that ingestion of virgin microplastics does not cause imminent harm to the adult gilt-head seabream during 45 days of exposure and an additional 30 days of depuration. The retention of virgin microplastics in the gastrointestinal tract was fairly low, indicating effective elimination of microplastics from the body of the fish and no significant accumulation after successive meals. Therefore, both the short- and the long-term retention potential of microplastics in the gastrointestinal tract of fish is close to zero. However, some large particles remained trapped in the liver, and 5.3% of all the livers analyzed contained at least one microplastic particle. In conclusion, the dietary exposure of S. aurata to 6 common types of virgin microplastics did not induce stress, alter the growth rate, cause pathology, or cause the microplastics to accumulate in the gastrointestinal tract of the fish.

Boris Jovanović, Kerem Gökdağ, Olgaç Güven and al., Marine Pollution Bulletin, Volume 130, May 2018, Pages 123-131

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