Session Chairs: Francois Galgani, French Research Institute for Exploitation of the Sea (IFREMER); Tatjana Hema, UN Environment Barcelona Convention Secretariat

This session is dedicated to scientists, stakeholders, institutions and managers to present and discuss their results from research and monitoring marine litter in the Mediterranean Sea and propose or discuss reduction measures in the framework of the Mediterranean Regional Action Plans.

Because of large cities, rivers and shore uses, some of the largest amounts of Municipal Solid Waste that are generated annually per person (208 – 760 kg/Year), because of tourism and intense fishing, 30% of the world’s maritime traffic, a closed basin, and insufficient infrastructure to process the wastes, the Mediterranean sea has been described as one of the most affected areas by marine litter in the world. As a consequence, densities were found to reach over 100,000 items per square kilometer of seabed and over 64 million particles per square kilometer in the Levantine basin. For the whole Mediterranean basin, it was predicted that, without management measures, the amount of plastic dumped may raise by a factor of more than 2 before 2025. Research also demonstrated the importance of hydrodynamics and the environmental impact of plastic at sea that include entanglement, ingestion, the rafting of species, social and economic harm.

While Mediterranean countries have shown important willingness to monitor and manage marine litter, still no regular monitoring is in place, most of the times experimental, with very little coverage of any marine compartment other than beach and stranded debris. There, the main groups of items are related to coastal-based tourism, recreation and the fishing and shipping industries. Then, the most effective measures and actions taken should respond to the major sources and input pathways, and also take into consideration feasibility and the specificity of this pollution in the Mediterranean Sea.

Number of key questions will have then to be considered in order to provide a scientific and technical background for a consistent monitoring, a better management system, and science based reduction measures. Further implementation of monitoring and measures is being considered within the UN Environment/MAP Regional Plan on Marine Litter Management in the Mediterranean, and in the lesser extent, the Marine strategy framework directive (MSFD), for EU countries. For the Mediterranean Sea, there is no unique/harmonized intervention, and the choice of an appropriate intervention is case specific, largely depending on the source and nature of pollution, country’s institutional characteristics and infrastructure, and the economy’s sectorial composition. This will need more coordination and exchange of information to better implement the possible instruments to reduce marine litter.

In the context of the 6IMDC, the session will provide a forum to enable the presentation of updated results from research and monitoring, identify research needs of knowledge, support monitoring and management of marine litter. This will also enable exchange among the parties and scientist or managers from other basins and finally coordinated actions to reduce marine litter.




Presence of plastics debris in Mediterranean pelagic and demersal fish of commercial interest

presenting: Dario Giani (Department of Physical, Earth and Environmental Sciences. University of Siena, Italy); authors: Dario Giani (Department of Physical, Earth and Environmental Sciences. University of Siena, Italy), Matteo Baini (Department of Physical, Earth and Environmental Sciences. University of Siena), Matteo Galli (Department of Physical, Earth and Environmental Sciences. University of Siena), Margherita Concato (Department of Physical, Earth and Environmental Sciences. University of Siena), Silvia Casini (Department of Physical, Earth and Environmental Sciences. University of Siena), Maria Cristina Fossi (Department of Physical, Earth and Environmental Sciences. University of Siena)

Plastic pollution in the ocean represent one of the biggest worldwide environmental issue, and the toxicity of chemicals associated with them has begun to raise concerns regarding the presence of anthropogenic debris in seafood. Particularly Mediterranean sea is one of the most affected by marine debris pollution.

In this study, we investigated 316 gastrointestinal tracts from demersal fish species (Mullus barbatus, Merluccius merluccius) and pelagic species (Engraulis encrasicolus) for the occurrence of plastic ingestion. Samples were collected in 4 different FAO Geographical Sub Areas of the Mediterranean sea. According to our knowledge, the present study surveyed the largest sample size for European hake and European anchovy ever analyzed in Mediterranean sea. This two species are the most important in term of economic value and quantity for the Italian fleet. Samples were digested using a KOH10% solution and incubated at 60° C overnight in order to analyse microplastics. The extracted particles were microscopically observed, photographed, measured and categorized according to size class, shape and colour. Microplastics were characterized using a stereo-microscope and polymers identified by Fourier Transform Infrared Spectroscopy (FT-IR). Airborne contamination was prevented during all procedures and blanks were performed every two samples. In 19% of total investigated fish plastic particles were detected, a total of 60 plastic debris (95% microplastics) were recorded. The highest frequency (22,5%) was found in European hake. No significant difference for litter ingestion between pelagic and demersal species were found.

These preliminary results represent an important step forward for the assessment of the presence of plastic debris in three of the most important commercial species for the Mediterranean fishery.


Microplastics in the Adriatic Sea: Occurrence, characterization, distribution and environmental management

presenting: Alessio Gomiero (International Resarch Institute of Stavanger, Norway); authors: Alessio Gomiero (International Resarch Institute of Stavanger, Norway), Giulio Pellini (Coop. “Mare Ricerca”), Pierluigi Strafella (National Research Council of Italy – Institute of Marine Science), Fabio Grati (National Research Council of Italy – Institute of Marine Science), Anna Nora Tassetti (National Research Council of Italy – Institute of Marine Science), Piero Polidori (National Research Council of Italy – Institute of Marine Science), Carmen Vega-Ferra (National Research Council of Italy – Institute of Marine Science), Giuseppe Scarcella (National Research Council of Italy – Institute of Marine Science), Marco Girasole (National Research Council of Italy – ISM), Gianna Fabi (National Research Council of Italy – Institute of Marine Science)

Recent years have seen a rapid rise in scientific interest in the occurrence of microplastic particles in the aquatic environment. Much of this research is showing that plastic micro-litter is a global problem, affecting the health status of aquatic ecosystems. At present, accurate assessment of the environmental, economic and societal impact of microlitter is hampered by a lack of standardization in extraction, purification and detection methods used for different environmental matrices. The objective of the present research was to develop a benchmark for the best available extraction, purification and detection technologies for use in seawater, sediment and marine biota samples from both water column and benthic environments. A sequential visual inspection, SEM, EDS, FTIR and µ-Raman microscopy and GCMS-Pyrolysis analysis was performed. The resulting multi-tiered approach, combining the various rapidity, accuracy, sensitivity and execution costs of the benchmarked techniques, is presented to promote the development of an effective microplastics monitoring program framework. The newly gained knowledge has been applied in a monitoring study based in the northern and central Adriatic Sea, a semi-enclosed basin characterized by a low water recirculation rate and elevated anthropic pressure associated with unsustainable fishing and high inputs of environmental contaminants. An extended sampling grid was adopted to provide information on both coastal and off-shore areas with 30 sites sampled for sediments and biota. Within this study emphasis was placed on the occurrence, polymeric relative abundance, plastic additive quantification, spatial and time distribution of microplastics as well as the correlation among plastic occurrence in sediments, water and biota. Presented data review published results and ongoing activities


How to detect the impact of marine debris on Mediterranean biodiversity? The three fold monitoring approach

presenting: Maria Cristina Fossi (Department of Physical, Earth and Environmental Sciences, University of Siena, Siena, Italy, Italy); authors: Maria Cristina Fossi (Department of Physical, Earth and Environmental Sciences, University of Siena, Siena, Italy, Italy), Matteo Baini (Department of Physical, Earth and Environmental Sciences, University of Siena, Siena, Italy), Cristina Panti (Department of Physical, Earth and Environmental Sciences, University of Siena, Siena, Italy)

The Mediterranean Sea has been described as one of the most affected areas by marine debris, including microplastics, in the world. Recent studies in the different regions of the basin suggested that some areas are affected by important concentration of microplastics and plastic additives, representing a potential risk for endangered species (baleen whales, sea turtles, filter feeders sharks) and for the all Mediterranean biodiversity. To cover the current knowledge gaps on this issue a harmonised methodological approach for the assessment of the marine debris impact on Mediterranean biodiversity is needed. The quantification of marine debris/microplastics in the marine environment can depend on several environmental factors and change according to multiple oceanographic features, and therefore, cannot reflect the potential impact on organisms and ecosystems. The information obtained by biondicator species could better integrate the spatial and temporal presence of marine litter/microplastics in the marine environment. In addition, the use of biondicators can allow to measure not only the occurrence of marine litter in the species and its environment but also the threat posed to organisms by the evaluation of contaminants accumulation and any related biological effect. To assess the harm by marine debris ingestion a threefold approach, simultaneously measuring the presence and effects (accumulation of plastic associated contaminants and biomarker responses), can provide the harm and the sub-lethal effects to organisms related marine litter ingestion. The gaps pointed out by this research and the bioindicators species selected could represent a step forward for the risk assessment and the implementation of future mitigation measure for the Mediterranean area, habitat and species affected by marine litter ingestion.


Marine Debris in the deep Mediterranean Sea

presenting: Michela Angiolillo (Istituto Superiore per la Protezione e Ricerca Ambientale (ISPRA), Italy); authors: Michela Angiolillo (Istituto Superiore per la Protezione e Ricerca Ambientale (ISPRA), Italy), Simonepietro Canese (Istituto Superiore per la Protezione e Ricerca Ambientale (ISPRA))

Marine debris is a recognized global ecological concern. Increasing number of studies in the Mediterranean Sea are investigating litter distribution and its influence on deep habitats, but little is still known about the extent of the problem. Litter enters the seas from both land-based and marine sources, and can travel long distances before sinking. Anthropogenic and environmental factors influence litter distribution and can converge it in accumulation areas, such as canyons. Several quantitative assessments of debris present in the deep seafloor (50–2,000 m depth) were carried out and debris abundance ranged from 0 to >15,000 items km−2, depending on location. Plastics typically constitute the most abundant debris, due to the large use and the high resistance to degradation. Plastic related-fishing debris is typically common in hard habitat, subject to intense fishing effort and tradition. The high commercial fishing effort of trawling and long lines fleets mainly operating in the basin represents, in fact, one of the major threat for the rich Mediterranean deep-sea environments, characterized by great diversity and abundance of structuring organisms, such as corals, gorgonians and sponges. In particular, these long-lived species with slow-growth rates and recovery ability play the important ecological role of ecosystem engineers in deep marine environments, creating complex three-dimensional habitats enhancing high biodiversity and ecosystem functioning at every level. The widespread presence of debris is impacting these vulnerable marine ecosystems. Standardized approaches and specific conservation measures are now an international priority and are needed in order to protect unique deep-ecosystems that are progressively disappearing.


Driving factors determining macroplastic distribution in seafloor habitats around the Balearic Islands, Spain

presenting: Carme Alomar (Instituto Español De Oceanografía, Spain); authors: Carme Alomar (Instituto Español de Oceanografía, Spain), Salud Deudero (Instituto Español de Oceanografía), Beatriz Guijarro (Instituto Español de Oceanografía)

Scientific surveys around the Balearic Islands, western Mediterranean Sea, have already demonstrated that plastic was present throughout most hauls conducted in a depth range varying from 51 to 800 m and up to 21 nm from the coast. In addition, plastic showed a high variability according to sampling locations with highest values in the western part of the archipelago. It is known that oceanographic regimes and plastic sources are determinant in the distribution and transportation of litter in marine environments. For this study, data from bottom trawl scientific surveys around the Balearic Islands were analyzed for a time series of 15 years (2001 -2015) at mesoscale level. Characteristic submarine geomorphology, geographical settings and bathymetric stratification in this sampling area might have an important role in the distribution of plastics. Thus, four depth strata; B (51-100 m); C (101-200 m); D (201-500 m) and E (501-800 m) along with habitat type (mud, sand, maërl, rhodophytes, crinoids), distance from the coast and currents were considered as potential factors that may determine spatial distribution of the plastic fraction in seafloor habitats. Preliminary results demonstrate that highest abundances of plastic are found in the first layers of the continental shelf (51-100 m). This result is important as it could be a valid indicator of the transfer of plastic from sea surface to the first bathymetric layers, where it accumulates and can be further transported to deeper layers through transportation and cascading processes.


Assessing marine litter in vulnerable coastal ecosystems response to tourism activities

presenting: Salud Deudero (Instituto Español de Oceanografía, Spain); authors: Salud Deudero (Instituto Español de Oceanografía, Spain), montserrat Compa (Centro Oceanografico de Baleares), Carme Alomar

Human derived-stressors such as maritime transit, anchoring, sewage effluents, fishing and diving activities and marine protected areas have altered the spatial distribution and density of benthic marine communities surrounding the Balearic Islands in the Western Mediterranean Sea. Recent scientific studies have indicated high loads of microplastics and marine litter concentrations in coastal areas demonstrating that pristine areas are polluted with microplàstics, an indication of transport between marine ecosystems. The Western Mediterranean is characterized by oligotrophic waters, partially due to the absence of river discharges, natural characteristics, oceanographic regimens and anthropogenic activities which determine the spatial and temporal distribution of marine litter in this region of the Mediterranean basin. In the absence of important commercial harbors and ports and heavy river discharges, the Balearic Islands have a strong stationary tourism with highest peaks in the summer months. The massive affluence of tourists (1.107,220 habitants in the islands vs 13.241,450 million tourism in 2016) alone with an increase in maritime activities (home port and transit cruises, recreational boats) are expected to foster sewage discharge, overloading waste water treatment plants increasing water treatment and sewage discharges, therefore directly affecting coastal ecosystems. Thus, this increase of tourism and marine litter are assessed and discussed.