Quantity and spatial distribution of seafloor marine debris in the Moroccan Mediterranean Sea

Cigarette butt pollution in popular beaches of Morocco: Abundance, distribution, and mitigation measures

Cigarette butts pose a significant challenge in managing solid litter, with an estimated 4.5 trillion of them being discarded into the environment annually. This study investigated the pollution of eleven beaches along the Moroccan Mediterranean by cigarette butts compared to other types of marine litter between 2018 and 2023. Sampling was conducted using the visual survey technique according to a standardized protocol. A total of 50, 575 items were collected with cigarette butts (14.62 %) and plastic caps/lids drinks (10.93 %) being the most common. Our survey of eleven beaches revealed 7395 cigarette butts, giving an average density of 0.06/m2 comparable to other countries in the Mediterranean. The analysis of the results shows significant differences in the abundance cigarette butts according to the beach typology, seasonality, sediment type, and number of beach users. Moreover, the study discovered a decrease in beach pollution during the COVID-19 pandemic lockdown, resulting in less litter collected compared to pre- and post-pandemic periods. The Cigarette Butt Pollution Index was categorized as very low pollution in M'diq and Kaa Asrass, low pollution in Ksar Sghir, Fnideq, Amsa, Oued Laou, significant pollution in Martil and Nador and sever pollution in Saidia and Sababia. The CBPI was higher during summer and winter, significantly associated with the density levels of beach users. The study recommends immediate action by the local administration to prevent the potential pollution of groundwater and sand by toxic substances leached from cigarette butts.

Binational survey using Mytilus galloprovincialis as a bioindicator of microplastic pollution: Insights into chemical analysis and potential risk on humans

Microplastic (MP) contamination in edible mussels has raised concerns due to their potential risk to human health. Aiming to provide valuable insights regarding the occurrence, physicochemical characteristics, and human health implications of MP contamination, in the present study, two nationwide surveys of MP contamination in mussels (Mytilus galloprovincialis) were conducted in Morocco and Tunisia. The results indicated that MP frequency ranged from 79 % to 100 % in all the analyzed samples. The highest MP density was detected in mussels from Morocco (gills "GI": 1.88 MPs/g ww^-1; digestive glands "DG": 0.92 MPs/g ww^-1) compared to mussels of Tunisia (GI: 1.47 MPs g^{- 1}; DG: 0.79 MPs g^{- 1}). No significant differences in MP density were found between the two organs (GI and DG) for both countries. MPs were predominantly blue and black fibers, and smaller than 1000 μm. Seven polymeric types were identified, of which PET, PP, and PE were the most abundant, accounting for >87 % of all samples. Scanning Electron Microscopy (SEM) coupled with Energy dispersive X-ray (EDX) showed that most MPs have noticeable signs of weathering and inorganic components on their surface. The highest MP daily intake was found in children, while the lowest was estimated in women and men. Moreover, the annual dietary exposure of MPs through mussel consumption was estimated to be 1262.17 MPs/year in Morocco and 78.18 MPs/year in Tunisia. The potential risk assessment of MPs in mussels based on the polymer hazard index (PHI) was estimated in the high-risk levels, implying that MPs may pose health risks to humans. Overall, this research suggests that the consumption of mussels represents a considerable MP exposure route for the Moroccan and Tunisian populations.

Integrated approach for marine litter pollution assessment in the southern Tyrrhenian Sea: Information from bottom-trawl fishing and plastic ingestion in deep-sea fish

Marine litter pollution threatens marine ecosystems and biodiversity conservation, particularly on seafloors where all anthropogenic waste naturally sinks. In this study, we provide new information on the composition, density and origin of seafloor macrolitter as well as on plastic ingestion in deep-sea fish from bottom-trawling by-catch in the southern Tyrrhenian Sea. Plastic constituted the highest fraction of litter in terms of density (64 %) and weight (32 %) and was also retrieved in the gastrointestinal traits of Chlorophthalmus agassizi, Coelorhynchus coelorhynchus and Hoplosthethus mediterraneus. FT-IR spectroscopy analysis on the seafloor macrolitter and the ingested plastics revealed the presence of artificial polymers including PE, PET/polyester, PA widely used for food packaging, plastic bags and several common products, especially Single Use Plastic (SUP). These results underline how poor waste management schemes or their incorrect application strongly contribute to marine litter accumulation on seafloors and plastic ingestion in deep-sea fish.

Occurrence, characteristics, and removal of microplastics in wastewater treatment plants located on the Moroccan Atlantic: The case of Agadir metropolis

Wastewater treatment plants (WWTPs) are some of the main sources of microplastics (MPs) in the environment. However, studies on the occurrence and removal efficiency of MPs in WWTPs are still scarce, especially in African countries. Thus, the aim of this work was to study the abundance of MPs in the influent and effluent of two WWTPs (Aourir and M'zar) from the Agadir metropolis (Moroccan Atlantic). The two WWTPs receive different wastewater inputs (domestic and industrial). In addition, the impacts of seasonality on the fate and removal efficiency were investigated. The results showed that the MPs abundance in the wastewater decreased from 188 MPs/L in the influent to 50 MPs/L in the effluent for Aourir WWTP (domestic inputs); while the abundance was greater in the M'zar WWTP (urban and industrial inputs) recording a mean value of 519 MPs/L and 86 MPs/L in the influent and effluent, respectively. MPs collected in the Aourir WWTP ranged from 290 to 3200 μm, while MPs from the M'zar WWTP, ranged from 330 to 4200 μm. Overall, the size range of 100-500 μm was the most abundant for both WWTPs. Fibers were the highest MPs morphotype found, followed by fragments. MP colors were mainly red, black, blue, and transparent for both treatment plants. Additionally, FTIR spectroscopy showed the presence of eight different polymers, mainly polyethylene (PE), polypropylene (PP), and polystyrene (PS). Seasonal variation analysis showed that MPs abundance in summer was significantly higher compared to other seasons. However, the comparison of the removal efficiency (RE) between the different seasons indicated that the winter season (74 %) recorded the highest RE for Aourir WWTP. Conversely, spring (87 %) recorded the highest RE for M'zar WWTP. SEM/EDX micrographs showed different degrees of weathering and chemical elements adhering to the surface of the MPs. The findings of the current study will serve as a baseline for future considerations about management strategies, wastewater reuse, as well as the understanding of the occurrence of microplastic pollution along the marine ecosystems of Morocco.

Marine macroinvertebrates fouled in marine anthropogenic litter in the Moroccan Mediterranean

The existence of floating marine litter in marine environments enhances the potential for the transport of fouling organisms using these substrates as vectors. In this study, we examined the fouling organisms on different types of litter stranded on two beaches of the Moroccan Mediterranean. The study revealed 13 fouling species belonging to 8 phyla (Arthropoda, Bryozoa, Annelida, Mollusca, Cnidaria, Echinodermata, Chlorophyta, and Ochrophyta) on marine litter. Rafting vectors were almost exclusively made up of plastics and could mainly be attributed to land-based sources. The most common fouling species were the crustacean Lepas pectinata, Lepas anatifera, Perforatus perforatus, and bryozoan species. More taxa were found on large litter than on small litter. Relative substratum coverage was highest for bryozoan sp. (31.0 %), green algae (29.0 %), Lepas anatifera (21.42 %), Lepas pectinata (17.8 %), and Perforatus perforatus (17.46 %). Our results suggest that the growing generation of plastic litter may enhance the probability of the introduction of non-native species into the Moroccan Mediterranean. Therefore, monitoring efforts are needed to identify vectors and the arrival of novel invasive species in this area.

Addressing the challenge of marine plastic litter in the Moroccan Mediterranean: A citizen science project with schoolchildren

In this study, based on data collected by citizen science, we studied the abundance, spatial and temporal distribution of marine litter in three beaches of the Moroccan Mediterranean. A total of 14,042 litter items were collected with an average abundance of 0.58 items/m². The most of litter were composed of anthropic polymeric materials, representing 74 % of the total litter collected. Plastics account for the majority of the items collected and are mainly caps/lids, crisp/sweet packets, plastic/polystyrene, cigarette butts and small plastic bags. Litter abundance displayed significant seasonal differences, with the highest during summer. Tourism and poor waste management practices are the major sources of plastic on the beaches surveyed. The use of the Clean Coast Index (CCI) and the Plastics Abundance Index (PAI) permits the classification of the three beaches in the Moroccan Mediterranean as a "moderately clean" coastal area with a "very high abundance" of plastics. In addition, the Hazardous Items Index (HII) allows classification of the region as highly polluted by hazardous litter. Best management measures are needed to promote the environmental quality of the beaches of the Moroccan Mediterranean.

Seafloor litter generated by coastal and offshore fisheries operations in the South Sea of Korea

Seafloor litter sources, distribution and density were assessed in a bottom trawl survey of the South Sea around Jeju Island by the Ara-ho training ship of Jeju National University. Samples were taken from 14 transects at a depth range of 60-120 m in areas with sandy and muddy substratum. Generally, mean densities varied from 26.9 items/km² to 62.4 items/km² and 104.8 kg/km² to 370.9 kg/km². Mean densities of total litter sampled was 46.3 items/km² and 228.6 kg/km². Derelict gears were the most common litter items (92 % of total litter) with mean densities of 44.3 items/km² and 228.1 kg/km². Gillnets and traps were the most derelict with densities reaching 4.9 items/km² and 99.2 kg/km² and 25.0 items/km² and 89.1 kg/km² respectively. The results of this study indicate that significant level of pollution in the South Sea are generated from commercial fishing activities and gillnets and traps being high risk derelict gears.

Microplastics pollution in sediments of Moroccan urban beaches: The Taghazout coast as a case study

This work describes the spatiotemporal analysis of microplastics (MPs) pollution in sediments collected on a high urbanized beach located in Taghazout coast, central Atlantic part of Morocco. The study area is mainly composed of moderately well-sorted fine sands with an average density of MPs that ranged between 915 MPs/kg in 2018 and 1448 MPs/kg in 2019. The most polluted sites were in the south part of Taghazout coast, close to facilities of where beachgoers are often found. Microplastic Pollution Index (MPPI), Microplastic Impact Coefficient (CMPI), Agglomerative Hierarchical Clustering (AHC), and Multidimensional Scaling (MDS) revealed spatiotemporal variation of MPs pollution. Thus, the principal component analysis (PCA) showed a low correlation between the sediment characteristics (i.e., grain size, sorting, skewness) and MPs densities. Overall, the outputs of this baseline recommend implementing plastic management strategies to eliminate or at least minimize the collateral effects generated by MPs pollution in sediments of urbanized beaches.

What Teachers Should Know for Effective Marine Litter Education: A Scoping Review

Marine litter has had a huge impact on the marine environment and the socio-economic activities that depend on healthy oceans. All members of the community must play their part to address marine litter. Teachers are agents of change that are capable of encouraging pro-environmental practices among the community that will reduce environmental issues, including marine litter. However, teachers were found to have limited knowledge regarding ocean literacy and marine pollution. A scoping review was conducted to identify various aspects of content knowledge related to marine litter education that has been recently conducted for school teachers and students. Web of Science, Scopus and ERIC databases were searched for articles published in English between 2015 and 8 July 2021. Fourteen peer-reviewed articles were selected for this study and were subjected to content analysis. Topics related to marine litter were frequently addressed. Meanwhile, topics related to teaching Environmental Education/Education for Sustainable Development (EE/ESD) were the least addressed. Benthic marine litter, solutions to marine litter and the introduction of new types of marine litter were identified as topics that need to be addressed in future marine litter education. This study lists content knowledge based on previous literature and identified the gaps, which will be useful for teachers to improve their knowledge and implement effective marine litter education in school.

Microplastics pollution along the central Atlantic coastline of Morocco

This baseline study describes the microplastic (MPs) problem on seven beaches located on Agadir, central Atlantic coast of Morocco. Microplastics abundances (densities) ranged from 7680 MPs/kg to 34,200 MPs/kg above other world beaches. The following shapes were found: fibers, fragments, films, and pellets. Fibers were the dominant typology with a 73%. Polyethylene (PE) was the predominant polymer in all beaches with an average percentage of 59%, followed by Polypropylene (PP - 18%), Polystyrene (PS - 9%), Polyvinyl chloride (PVC - 8%), and Ethylene-vinyl acetate (EVA - 6%). Microplastics abundances presented in this work suggest continuous inputs of plastics of all sizes and types. Also, all observed shapes highlight a combination of sources (primary and secondary). Central Atlantic Moroccan beaches are currently affected by extreme values of MPs that demand urgent interventions to restore environmental quality.

Proposing a new solution for marine debris by utilizing on-board low-temperature eco-friendly pulverization system

Developing an effective and efficient recycling process for marine debris (MD) is one of the most urgent issues to maintain environmental sustainability on Earth. However, restricted storage capacities and secondary pollution (e.g., microbial adhesion, putrefaction) limit the proper MD recycling. Here, we proposed a complete eco-friendly low-temperature MD pulverizing system that utilizes excessive liquefied natural gas (LNG) cold energy (LCE) in an LNG propulsion ship to improve the efficiency and effectiveness of MD recycling. The prototype design of the low-temperature pulverization (LTP) system showed that consumable refrigerant (liquid nitrogen) up to 2831 kg per hour could be substituted. Furthermore, with a 20% ship output, 1250 kg of MD could be treated with 363 kg of additional refrigerant. In addition, LTP systems utilizing LCE could increase the storage capacity by more than 10 times compared to bulk MD while minimizing the required energy consumption. To determine the feasibility of LTP for MD recycling, four types of plastics obtained from actual MD from a coastal area in Busan, Korea were classified and tested.

Personal protective equipment (PPE) pollution associated with the COVID-19 pandemic along the coastline of Agadir, Morocco

The increasing use of personal protective equipment (PPE) as a sanitary measure against the new coronavirus (SARS-CoV-2) has become a significant source of many environmental risks. The majority of the governments enforce the use of PPE in public areas, such as beaches. Thus, the use and disposal of PPE have compromised most solid waste management strategies, ultimately leading to the occurrence of PPE polluting the marine environment. The present study aimed to monitor the PPE pollution associated with COVID-19 along the coastline of Agadir, Morocco. In parallel, the influence of the activities carried out in each sampled beach before and after the lockdown break was reported. Overall, a total number of 689 PPE items were identified, with a mean density of 1.13 × 10^-5 PPE m^-2 (0-1.21 × 10^-4 PPE m^-2). The majority of the PPE items found were face masks (96.81%), out of which 98.4% were surgical masks and 1.6% were reusable cloth masks. The most polluted sites were the beaches with recreational activities, followed by surfing, and fishing as the main activity. Importantly, PPE density increased significantly after lockdown measures. Additionally, the discarded PPE sampled in the supralittoral zone was higher than PPE recorded in the intertidal zone. This confirms that PPE items are driven by the beachgoers during their visit. PPE items are a source of microplastic and chemical pollutants, a substrate to invasive species colonization, and a potential threat of entanglement, ingestion, and/or infection among apex predators. In the specific case of Agadir beaches, significant efforts are required to work on the lack of environmental awareness and education. It is recommended to improve beach cleaning strategies and to penalize incorrect PPE disposal. Additional alternatives may be adopted, as the involvement of biodegradable materials in PPE manufacturing, recycling through pyrolysis, and encouraging reusable and washable masks.

Microplastic ingestion by Atlantic horse mackerel (Trachurus trachurus) in the North and central Moroccan Atlantic coast between Larache (35°30'N) and Boujdour (26°30'N)

Horse mackerel is a semi-pelagic species found in abundance in the Moroccan coasts and occupies the first ranks in the catches landed by the coastal fleet. In this study, we investigated the ingestion of Polyamide, Acrylic and Polystyrene by Atlantic horse mackerel, in the Moroccan Atlantic coastal area located between Larache (35°30'N) and Boujdour (26°30'N). The objective is to map the spatial distribution of horse Mackerel containing microplastics (MPs) in their stomachs and identify hot spot areas. We also aim to verify the most ingested polymer by this fish characterized by significant daily vertical migrations. The results show that the three studied polymers were detected in the stomach contents of more than 73% of studied fishes. The hot spot areas are located more in the northern part where urbanization and fishing activity are important. Polyamide, the densest polymer, is the most abundant (86% of cases), followed by acrylic. These two polymers were found in association in 47% of cases. No correlation between the presence of MPs in the stomach contents and the size of the individual fishes was noted. Interestingly, the group of mature specimens ingested more MPs than the immature group.

Marine litter on the shallow seafloor at Natura 2000 sites of the Central Eastern Adriatic Sea

Shallow seafloor marine litter (ML) is the least studied component of ML, and a better understanding of its distribution and accumulation patterns is needed to develop efficient management practices. Abundance and composition of seafloor ML were quantified in two eastern Adriatic Natura 2000 sites (Vis Island and Pakleni Islands), applying a structured sampling design to test whether the intensity of nautical tourism or exposure to prevailing winds and currents are significant drivers determining the ML distribution on shallow, coastal seafloor. ML was widespread and present in considerable amounts across the entire studied area, regardless of the remoteness from most known potential ML sources. Tourism intensity and exposure seem not to be significant predictors of ML accumulation in the investigated Natura 2000 sites. ML abundances displayed large small-scale spatial variation, while for ML composition at a larger scale, regional differences between the two Natura 2000 sites were detected. The Pakleni Islands are mainly polluted by glass items, suggesting a local vessel-based source. The ML composition on Vis Island, with a predominance of plastics, is more determined by long-distance transport. The study indicates the complexity and multi-layeredness of processes driving the patterns of seafloor ML accumulation. Hence, it is suggested to mitigate the issue by addressing the root causes: inadequate waste management and lack of public awareness.

Effects of the 2011 Tohoku earthquake and tsunami on the abundance and composition of anthropogenic marine debris on the continental slope off the Pacific coast of northeastern Japan

The abundance and composition of anthropogenic marine debris from 2012 to 2014 was assessed according to three bottom trawl surveys conducted on the upper continental slope between 198 m and 501 m off the Pacific coast of northeastern Japan. The surveys quantitated marine debris as follows: 33.52-164.62 items km^-2 (January to July 2012), 91.68-215.11 items km^-2 (November 2012 to May 2013), and 160.13-178.19 items km^-2 (November 2013 to May 2014). Plastic bags or household materials mainly dominated terrestrial sources of debris. Principal component analysis latitudinally divided the study area according to debris abundance caused by geographical and hydrodynamic features. The long-term effect of tsunami-associated debris on the seafloor environment was recognized, because terrestrial sources such as heavy household materials were most abundant throughout the study period, with the additional accumulation of fishing gear and plastic bags.

Marine debris in Moroccan Mediterranean beaches: An assessment of their abundance, composition and sources

Morocco is well known for its attractive Mediterranean beaches, which play an important economic role. With the fast development and growth, these beaches have become more contaminated by marine debris. This paper examined the abundance, composition and marine debris sources on five beaches in the Moroccan Mediterranean during 2019 four seasons. A total of 7839 marine debris were collected from the five beaches with a total weight of 231 kg. The average density of the debris collected was 0.20 ± 0.098 items/m². Polymer materials constituted the majority of debris found, with a percentage of 71.36%, followed by paper/cardboard (11.50%), metal (5.77%), processed wood (5.34%), cloth/textile (2.51%) and glass/ceramics (1.76%). Human recreational activities were the main source of debris (70.13%), followed by smoking-related (13.98%). Debris density appears to be particularly influenced by beach users. Awareness campaigns are needed for beach users to improve the quality of the beaches.

The first report of deep-sea litter in the South-Western Caribbean Sea

Marine litter is a world-wide problem, but the knowledge on this topic in remote areas such as the poles and the deep-sea is still limited. This paper seeks to provide the first accounts of deep-sea litter in the South-Western Caribbean Sea. The survey used 5066 still images from ROV video surveys around four hydrocarbon exploratory drilling zones. Forty-eight deep-sea litter items were found at depths between 427 and 2561 m, and analyzed by three different marine litter classifications. Plastic was the most frequent material (65%) and general litter the main category (69%). Almost half of the deep-sea litter items were found close to marine organism. This baseline is a first step to further research of human impact on the marine bottoms of the Caribbean. The paper highlights the importance of deep-sea litter as a descriptor of marine pollution, and the role of scientific cooperation between off-shore industry and the academy.

Estimation of tsunami debris on seafloors towards future disaster preparedness: Unveiling spatial varying effects of combined land use and oceanographic factors

A large amount of tsunami debris from the Great East Japan Earthquake in 2011 was sunk on the seafloor and threatened the marine ecosystem and local communities' economy, especially in fisheries. However, few studies estimated spatial accumulations of tsunami benthic debris, comparing to their flows on the ocean surface. Here, a spatially varying coefficient model was used to estimate tsunami debris accumulation considering the spatial structure of the data off the Tohoku region. Our model revealed the number of vessels nearest the coast at the tsunami event had the highest positive impact, whereas the distance from the coast and kinetic energy influenced negatively. However, the effect of the proximity to the coast wasn't detected in the Sendai bay, indicating spatial dependency of these effects. Our model estimation provides the fundamental information of tsunami debris accumulation on the seafloor, supporting early reconstruction and risk reduction in marine ecosystems and local communities.

Initial beach litter survey in a conservation unit (Santa Isabel Biological Reserve, Sergipe) from northeast Brazil

This study aimed to evaluate the presence and distribution of litter on four beaches in a conservation unit in northeast Brazil (Santa Isabel Biological Reserve; SIBR), and at the tourist beach of Pirambu (PB). Samplings occurred during low tide in March 2018 and May 2018. We observed that PB contained a higher number of litter items (March = 12.5 ± 1.2 items m^-1; May = 6.1 ± 2.1 items m^-1) when compared to SIBR beaches with a general average of 1.7 ± 0.8 items·m^-1 (March) and 2.1 ± 1.1 items·m^-1 (May). Plastics were the most quantified items (~ 80% in PB and ~ 90% in SIBR). SIBR beaches were considered moderately clean. Despite access restriction on the SIBR beaches, the considerable amount of litter found in those beaches (mainly near the villages) calls attention to the importance of waste management improvements in Sergipe cities.

Bottom-trawl catch composition in a highly polluted coastal area reveals multifaceted native biodiversity and complex communities of fouling organisms on litter discharge

Areas subjected to anthropogenic impacts are important to test the effect of stressors on local biota. We assessed with trawl net the composition and abundance of megafauna, litter, and litter-fouling communities in the soft bottoms of the National Interest Priority Site (NIPS) of Bagnoli-Coroglio (Gulf of Naples, Tyrrhenian Sea) at different depths. The megafauna accounted for 3444 specimens referred to 133 taxa (91 invertebrates and 42 fishes), for a biomass of ~102 kg and including species of wide ecological and commercial interest. Metrics of community structure yielded high values. The NIPS, hence, is characterized by a high biodiversity. Litter accounted for 3590 items, mostly in plastic and ranging between 10< × ≤20 cm, for a weight of ~260 kg, with values of 299.2 item/km² and 21.67 kg/km². The putative origin of most items was land-based (83.6%), whereas sea-based litter accounted for 16.4%. More than 50% of the litter items found showed colonization by invertebrates and/or molluscan egg masses. Marine benthic litter, thus, locally constitutes a complex issue since litter items hosted complex communities of fouling organisms. Future remediation procedures should take the resident NIPS biota into account and not disrupt the environmental balance of the area.

Macro litter distribution of the Turkish Mediterranean coasts dominated by pleasure crafts

Litters are the most pollutants in progress of the interests in marine environments. Macro litter samples were collected from 66 stations to estimate litter contribution from pleasure crafts along bays of the most Turkish touristic coasts (Antalya-Muğla) by the divers in June/July 2019. Average abundance and weight were 19 items/km² and 18 kg/km², respectively. The most abundant litter was plastics and the most contributors in weight were metals, followed by glass/ceramics. Abundance of the litters increased with number of pleasure crafts in active in summer. Pleasure crafts contributed most abundantly with the personal wares to the total litter, particularly in the coasts of Muğla. Litters were differentiated with interaction of region × bottom depths. The litter composition and abundance were different between region of Antalya in active mostly by tour boats and region of Muğla by private yachts. The litter types were however correlated with sea surface temperature.

A trawl survey of seafloor macrolitter on the South African continental shelf

Demersal trawls provide an index of seafloor macrolitter abundance, but there are no published data from sub-Saharan Africa. We collected litter items from 235 trawls conducted to assess fish abundance off South Africa. Only 17% of trawls contained litter (3.4 items·km^-2, 2.1 kg·km^-2 but only 0.2 kg·km^-2 excluding four megalitter items). Plastic items predominated (88%), of which 77% floated once cleaned of epibionts. One LDPE bag manufactured three months before being caught carried pelagic goose barnacles Lepas anserifera, confirming that biofouling leads to rapid sinking of floating plastics. Fishery/shipping wastes comprised 22% of litter items (98% by mass; 73% excluding megalitter items); the remainder was general waste - mostly packaging or other single-use items - that could come from land- or ship-based sources. Litter was more abundant in deep water close to Cape Town. The annual demersal trawl survey is a useful way to monitor seafloor litter off South Africa.

Shelf-life and labels: A cheap dating tool for seafloor macro litter? Insights from MEDITS surveys in Sardinian sea

The global plastic economy demands to reduce the flow of plastic into oceans and promote remedial actions for already accumulated seafloor litter. In this perspective, baseline levels of contamination and tools for dating litter items in order to assess the efficacy of those actions, are thus needed. In this note we discuss the utility of introducing the acquisition of shelf-life and labels features from litter items into already established standardized protocols such as the one proposed by MEDiterranean International Trawl Survey (MEDITS). Our investigation was conducted on 612 high resolution images of litter items collected in each haul, which was retrieved during 6 years of surveys (2013-2018) around Sardinian sea (central western Mediterranean). While for the majority of items (89%) expiration date or labels were not present or legible, over 50% of dated items were likely dumped at sea from a period <5 years. In this perspective, this sort of data could represent a useful tool for monitoring the effectiveness of input reduction actions that implicitly rely on the gradual reduction of recently dumped items.