New publication: review on MPs sampling methods in the Mediterranean

Abstract: The lack of standardization on the definition and methods in microplastic (MP) research has limited the overall interpretation and intercomparison of published data. This has presented different solutions to assess the presence of these pollutants in the natural environment, bringing the science forward. Microplastics have been reported worldwide across different biological levels and environmental compartments. In the Mediterranean Sea, numerous research efforts have been dedicated to defining the MP pollution levels. The reported MP concentrations are comparable to those found in the convergence zone of ocean gyres, pointing to this basin as one of the world’s greatest plastic accumulation areas. However, to what extent are the data produced limited by the methods? Here, we present the results of a systematic review of MP research methods and occurrence targeting the seawater and sediment bodies of the Mediterranean Sea. Based on this dataset, we 1) assess the discrepancies and similarities in the methods, 2) analyze how these differences affect the reported concentrations, and 3) identify the limitations of the data produced for the Mediterranean Sea. Moreover, we reaffirm the pressing need of developing a common reporting terminology, and call for international collaboration between Mediterranean countries, especially with North African countries, to provide a complete picture of the MP pollution status in this basin.

Simon-Sánchez L., Grelaud M., Franci M. and Ziveri P. 2021: Are research methods shaping our understanding of microplastic pollution? A literature review on the seawater and sediment bodies of the Mediterranean Sea. Environmental Pollution, 292, Part B, 118275. DOI: 10.1016/j.envpol.2021.118275

New publication: optimization of tissue digestion for MPs analysis

Abstract: Over the last few years, different digestion protocols have been proposed to extract microplastics from mussels, an important product from aquaculture and a relevant economic resource, always scrutinized as a potential pollutant concentrator. In this study, a full factorial experimental design technique has been employed to achieve efficiency in removing biological materials while maximizing the recoveries of five common microplastics (polyethylene, polystyrene, polyethylene terephthalate, polypropylene and polyamide). A robust setpoint was calculated, 2.5% potassium hydroxide at 60 °C for 3 h with 5% hydrogen peroxide and 2.7% of methanol, permitting the quantitative digestion of mussel tissues and recovery of microplastics. These experimental conditions were successfully used to digest whole mussels bought from a local market, which possess high levels of microplastic contamination (41 items/g dry weight). The results highlight the importance of optimizing protocols to develop robust, easy to use and cheap quantitative approaches for analysing microplastic accumulation in edible organisms.

Fraissinet S., Pennetta A., Rossi S., De Benedetto G. E. and Malitesta C. 2021: Optimization of a new multi-reagent procedure for quantitative mussel digestion in microplastic analysis. Marine Pollution Bulletin, 173, Part A, 112931. DOI: 10.1016/j.marpolbul.2021.112931

New publication: marine litter in Mediterranean beaches

Abstract: The Mediterranean Sea and its coastal systems are threatened by intense anthropogenic pressures including rapid accumulation of marine litter by diverse human activities. The region, which is the world’s leading touristic destination, has to face a seasonal increase of waste generation due to the seasonal influx of visitors. The beaches, extremely crowded during the summer, are particularly vulnerable since they are proven to be concentrated accumulation zones and one of the main gateways of litter to enter the marine system. We found that the accumulation rates of marine litter on Mediterranean island beaches follow a seasonal pattern, increasing up to 4.7 times during the high season, representing a daily load of (40.6 ± 11.5) 106 items/day extrapolated to all the islands of the region. We developed an accumulation index to assess the dynamics of marine litter and support efficient mitigation strategies by local authorities. To limit marine litter production attributable to recreational activities, a series of pilot actions implemented during the high touristic season, demonstrated a substantial reduction (up to 52.5%). The implementation towards an efficient and sustainable tourism business model is urgently required.

Grelaud M. and Ziveri P. 2020: The generation of marine litter in Mediterranean island beaches as an effect of tourism and its mitigation. Scientific Reports, 20, 20326. DOI: 10.1038/s41598-020-77225-5

New publication: MPs in subsurface western equatorial Atlantic

Abstract: We provide a baseline assessment of the density and types of microplastics in the western equatorial Atlantic. The highest microplastics density was found in coastal stations near urbanized sites, large tropical estuaries, and fishing grounds. With regard to microplastics composition, most of the identified particles were fibers/filaments, styrofoam, hard and soft plastic, paint, and glass/acrylic. Fibers/filaments were the most abundant (~80%) and occurred at all stations, in both types of mesh nets. Hard plastic particles were frequent (78%) only in the 120 μm mesh net. The mean density recorded in the 120 μm mesh net was about seven times greater than that in the 300 μm mesh net, suggesting that the larger mesh size net did not lead to an accurate description of microplastics density in the pelagic environment or the degree of risk to which organisms are exposed.

Martins Garcia T., Coelho Campos C., Targino Mota E. M., Oliveira Santos N. M., de Santana Campelo R. P., Gomes Prado L. C., Melo Junior M. and de Oliveira Soares M. 2020: Microplastics in subsurface waters of the western equatorial Atlantic (Brazil). Marine Pollution Bulletin, 150, 110705. DOI: 10.1016/j.marpolbul.2019.110705

New publication: MPs in corals

Abstract: This article seeks to present a summary of knowledge and thus improve awareness of microplastic impacts on corals. Recent research suggests that microplastics have a variety of species-specific impacts. Among them, a reduced growth, a substantial decrease of detoxifying and immunity enzymes, an increase in antioxidant enzyme activity, high production of mucus, reduction of fitness, and negative effects on coral-Symbiodiniaceae relationships have been highlighted in recent papers. In addition to this, tissue necrosis, lower fertilization success, alteration of metabolite profiles, energetic costs, decreased skeletal growth and calcification, and coral bleaching have been observed under significant concentrations of microplastics. Furthermore, impairment of feeding performance and food intake, changes in photosynthetic performance and increased exposure to contaminants, pathogens and other harmful compounds have also been found. In conclusion, microplastics may cause a plethora of impacts on corals in shallow, mesophotic, and deep-sea zones at different latitudes; underlining an emerging threat globally.

de Oliveira Soares M., Matos E., Lucas C., Rizzo L., Allcock L. and Rossi S. 2020: Microplastics in corals: An emergent threat. Marine Pollution Bulletin, 161, 111810, DOI: 10.1016/j.marpolbul.2020.111810

i-plastic Kickoff Meeting

i-plastic kickoff meeting was virtually held on the 22nd of September 2020 due to COVID-19 restrictions. The meeting was hosted by Project Coordinator Patrizia Ziveri from the ICTA-UAB and attended by the 5 partners from Spain, Italy, Portugal and Brazil. The objectives of each work package to achieve the main goals of i-plastic were presented by the WP leaders, while the overall project management, communication plan and data management was detailed by the coordination team.