Descrizione 1
Marco Matiddi, Arianna Orasi, Raffaella Piermarini, Cecilia Silvestri
Italy, in application of the Marine Strategy Framework Directive, has implemented an extensive marine litter monitoring program since 2015, including micro-litter present in the surface layer of the water column. This monitoring is conducted by the National System for Environmental Protection (of which ISPRA is a part), under the coordination of the Ministry of Environment and Energy Security (MASE). The composition, quantity, and distribution of surface micro-litter are essential parameters for achieving the good environmental status of marine waters, the objective of the Directive. Micro-litter are particles smaller than 5 mm, whose origin is difficult to identify once dispersed in the environment. These particles derive from both primary sources, such as pellets and microbeads used in cosmetics or abrasive products, and secondary sources, such as the fragmentation of macro-litter. With the data processing carried out from 2016 to 2022, it was possible to define a median density value of micro-particles present in our seas, equal to 0.04 micro-particles per m², or 40,000 micro-particles per km². This value is confirmed by adding the 2023 data to the series. At the Mediterranean level, the Barcelona Convention has set a threshold value of 0.000845 micro-particles per m² (845 micro-particles per km²), therefore, compared to this value, Italy is still far from achieving good environmental status.
The definition of "good environmental status" (GES) for Descriptor 10, according to the Ministerial Decree of 15 February 2019, states: "G 10.1 The composition and quantity of marine litter on the coastline, in the surface layer of the water column, on the seabed, of micro-litter in the surface layer of the water column, and of marine litter ingested by marine animals are such that they do not cause significant impacts on the coastal and marine ecosystem." The indicator allows measuring the number of micro-particles per m² of marine surface, providing information on the level of micro-litter pollution in the sea. Micro-particles are defined as anthropogenic particles (solid, synthetic, and/or polymeric matrix) smaller than 5 mm. Micro-particles in the sea have both primary and secondary origins. The primary includes the production of micro-particles such as pellets and microbeads used in cosmetics or abrasive cleaning products produced by industries. The secondary comes from the fragmentation and degradation of macro-litter into small particles. The degradation of objects, with the formation of micro-particles, can impact marine organisms through direct or involuntary ingestion, thus entering the food web.
To measure the concentration of micro-litter on the marine surface. The reduction over time of the rate of increase of micro-litter in the surface layer of our seas allows evaluating whether the marine environmental status is improving as a result of specific actions that foresee the reduction of input and the increase of litter collection both at sea and on the coasts.
- Directive 2008/56/EC.
- Legislative Decree No. 190 of 13 October 2010.
- Commission Decision (EU) 2017/848 of 17 May 2017 laying down criteria and methodological standards on good environmental status of marine waters as well as specifications and standardized methods for monitoring and assessment, and repealing and replacing Decision 2010/477/EU.
- UNEP/MAP Barcelona Convention - United Nations Environment Programme Mediterranean Action Plan UNEP/MED WG.550/13.2023. Updated Baseline Values (BV) and Threshold Values (TV) for IMAP Common Indicator 23 (Seafloor macro-litter, Floating micro-plastics).
Descrizione 2
Baini, M., Fossi, M.C., Galli, M., Caliani, I., Campani, T., Finoia, M.G., Panti, C., 2018. Abundance and characterization of microplastics in the coastal waters of Tuscany (Italy): The application of the MSFD monitoring protocol in the Mediterranean Sea. Mar. Pollut. Bull. 133, 543–552. https://doi.org/10.1016/J.MARPOLBUL.2018.06.016.
Caldwell, J., Muff, L.F., Pham, C.K., Petri-Fink, A., Rothen-Rutishauser, B., Lehner, R., 2020. Spatial and temporal analysis of meso- and microplastic pollution in the Ligurian and Tyrrhenian Seas. Mar. Pollut. Bull. 159, 111515. https://doi.org/10.1016/j.marpolbul.2020.111515.
De Lucia G.A., Vianello A., Camedda A., Vani D., Tomassetti P., Coppa S., Palazzo L., Amici M., Romanelli G., Zampetti G., Cicero A.M., Carpentieri S., Di Vito S. and Matiddi M., 2018. Contamination of the Italian Minor Islands by micro-plastics pollution: survey of the clearest Italian sea waters. Water. 10 (8),1108. https://doi.org/10.3390/w10081108.
De Lucia G.A., Caliani I., Marra S., Camedda A., Coppa S., Alcaro L., Campani T., Giannetti M., Coppola D., Cicero A.M., Panti C., Baini M., Guerranti C., Marsili L., Massaro G..,Fossi M.C. and Matiddi M. 2014. Amount and distribution of neustonic micro-plastic off the Western Sardinian coast (Central-Western Mediterranean Sea). Marine Environmental Research. 100, 10-16. DOI: 10.1016/j.marenvres.2014.03.017.
Marrone, A., La Russa, M.F., Randazzo, L., La Russa, D., Cellini, E., Pellegrino, D., 2021. Microplastics in the center of mediterranean: Comparison of the two calabrian coasts and distribution from coastal areas to the open sea. Int. J. Environ. Res. Public Health 18, 20. https://doi.org/10.3390/ijerph182010712.
MSFD-TSGML 2013. Guidance on monitoring of marine litter in European Seas. A guidance document within the common implementation strategy for the marine strategy framework directive. EUR-26113 EN. JRC Scientific and Policy Reports JRC83985. http://mcc.jrc.ec.europa.eu/documents/201702074014.pdf.
UNEP/MED WG.482/19. 2020. Monitoring Guidelines/Protocols for Floating Microplastics
UNEP/MED WG.567/Inf.3.2023. 2023 Mediterranean Quality Status Report
Difficulty in assessing the trend of micro-litter concentrations on the marine surface unless very long historical series are available.
Qualificazione dati
http://www.db-strategiamarina.isprambiente.it/app/#/
National
2015-2023
Qualificazione indicatore
The indicator expresses the concentration of micro-litter in the surface layer of the water column. The concentration of microplastics is expressed as the number of items per m² of sampled seawater. The calculation of the quantity of micro-particles/m² is performed based on the surface area of filtered water (S) calculated using the following formula: S=L×lS=L×l where:
- LL is the length of the sampled linear path,
- ll is the width of the manta mouth.
In 2023, compared to 2022, an increase in micro-litter concentrations was observed in the different Italian marine subregions: Adriatic Sea, increase of 38%; Ionian Sea and Central Mediterranean, increase of 76%; Western Mediterranean, increase of 19%. At the European level, a threshold value to determine the good environmental status regarding marine micro-litter has not yet been defined. However, within the framework of the Barcelona Convention, a threshold value of 0.000845 micro-particles per square meter, equivalent to 845 micro-particles per square kilometer, has been established for the Mediterranean. The analysis of the data collected in 2023 revealed a median density of micro-particles on the surface of our seas equal to 0.04 per square meter, or 40,000 micro-particles per square kilometer. The current level of micro-particles is, therefore, significantly higher than the threshold value of 845 micro-particles per km², indicating that we are still far from achieving good environmental status.
Assessing the trend of micro-litter concentrations on the marine surface is complex unless sufficiently long historical series of data are available. Calculating the median of micro-litter concentrations on the marine surface from 2016 to 2022 yields a value of 0.04 micro-particles per m². The addition of 2023 data did not change this median, suggesting a certain stability of the phenomenon. Nevertheless, the use of variable-based indices allowed detecting significant annual variations, indicating the presence of fluctuations over time not reflected by the overall median. The spatial distribution of this pollutant is influenced by multiple interacting factors. Floating microplastics are transported by seawater movements, and their distribution will reflect surface circulation and wind. In coastal areas, various anthropogenic factors can influence their accumulation and dispersion. The proximity to large cities and anthropogenic activities (e.g., coastal tourism, recreational boating, agriculture, ports, industrial activities, fishing, aquaculture) can significantly contribute to the amount of marine litter in marine environments.
Dati
figura abstract
Figure 1: Frequency distribution of sub-region microparticles
ISPRA processing on ARPA data
Figure 2: Contribution of each sub-region to the territorial concentration of microparticles (2023)
ISPRA processing on ARPA data
Figure 3: Annual concentration of micro-waste in the Adriatic Sea
ISPRA processing on ARPA data
Gray bars represent the floating-based variability index. The blue line represents the annual percentage of microwaste. N is the number of samples made in the year.
Figure 4: Annual concentration of micro-waste in the Ionian Sea and Central Mediterranean
ISPRA processing on ARPA data
Gray bars represent the floating-based variability index. The blue line represents the annual percentage of microwaste. N is the number of samples made in the year.
Figure 5: Annual micro-waste concentration in the Western Mediterranean
ISPRA processing on ARPA data
Gray bars represent the floating-based variability index. The blue line represents the annual percentage of microwaste. N is the number of samples made in the year.
From 2015 to 2023, marine micro-litter monitoring campaigns were conducted in the three subregions: Western Mediterranean, Ionian Sea and Central Mediterranean, and Adriatic Sea. 2015 represented the pilot year for the development of sampling and analysis methods, while the data collected from 2016 to 2023 were used to populate the indicator. The data analysis was performed using moving base indices, which, considering the annual concentrations of micro-litter, highlight the variations in the intensity of the phenomenon year by year. The distribution of data by subregion in the period 2016-2023 (Figure 1) is asymmetric: the sampled micro-litter values are more concentrated in the classes between 0 and 0.04 micro-particles/m² and more dispersed for values above the median. The 2023 data confirm the median concentrations found in the period 2016-2022, indicating stability of the phenomenon. The territorial distribution of micro-litter shows variations compared to previous years. The contribution of the Adriatic subregion remains constant, passing from 39.7% in 2022 to 39.6% in 2023. In the Western Mediterranean, the contribution increased from 33.8% in 2022 to 39% in 2023. Conversely, in the Ionian Sea and Central Mediterranean, a decrease is observed from 26.4% to 21.4% (Figure 2). Figures 3, 4, and 5 show the annual concentration of micro-litter for each subregion. The gray bars represent the moving base variability index, while the blue line indicates the annual percentage of micro-litter. The letter "N" represents the number of samples taken in the year, useful for verifying the stability of sampling over time.
In the Adriatic Sea, the percentage of micro-litter concentration (blue line) increased from 10% in 2022 to 14% in 2023. When the moving index is above 100, it indicates an increase in the phenomenon compared to the previous year; therefore, in the Adriatic subregion, with a moving index of 138, it means that in 2023 there is a 38% increase in micro-litter concentration compared to 2022 (Figure 3).
In the Ionian Sea and Central Mediterranean subregion (Figure 4), the percentage of micro-litter increased from 2.4% in 2021 to 5.5% in 2022, reaching 9.35% in 2023 with a moving index of 176, indicating a 76% increase in micro-litter concentration in 2023. In the Western Mediterranean, the intensity of micro-litter concentration increased from 10% in 2022 to 12% in 2023 and a moving index of 119, indicating in this case a 19% increase (Figure 5). Analyzing the trend of the blue line in the three graphs, the difficulty in defining a clear trend emerges, with an apparently decreasing trend in previous years and increasing in the last year (Figures 3, 4, 5).