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Evaluating the effects of anthropogenic pressure on the marine environment is one of the focal objectives in identifying strategies for its use, conservation and restoration. In this paper, we assessed the effects of chemical pollutants, grain size and plastic litter on functional traits, biodiversity and biotic indices. The study was conducted on the benthic communities of three harbours in the central Mediterranean Sea: Malta, Augusta and Syracuse, subjected to different levels of anthropogenic stress (high, medium and low, respectively). Six traits were considered, subdivided into 22 categories: reproductive frequency, environmental position, mobility, life habit, feeding habit and bioturbation. Functional diversity indices analysed were: Functional Divergence, Quadratic Entropy, Functional Evenness and Functional Richness. To assess the trait responses to environmental gradients, we applied RLQ analysis, which considers simultaneously the relationship between three components: environmental data (R), species abundances (L) and species traits (Q). From our analyses, significant relationships (P-value = 0.0018 for permutation of samples, and P-value = 0.00027 for permutation of species) between functional traits and environmental data were highlighted. The trait categories significantly influenced by environmental variables were those representing feeding habits and mobility. In particular, the first category was influenced by chemical pollutants (organotin compounds and polycyclic aromatic hydrocarbons) and grain size (silt and sand), while the latter category was influenced only by chemical pollutants. Pearson correlations performed for functional vs biotic and diversity indices confirmed the validity of the chosen conceptual framework for harbour environments. Finally, linear models assessing the influence of stressors on functional parameters underlined the link between environmental data vs benthic and functional indices. Our results highlight the fact that functional trait analysis provides a useful and fast method for detecting in greater depth the effects of multiple stressors on functional diversity in marine ecosystems. Image 1 • The expression of functional traits is negatively correlated to anthropogenic pollutants. • Data from taxonomy and functional traits approaches have similar trends. • Functional traits provide a useful method for environmental stress monitoring. [ABSTRACT FROM AUTHOR]

Fenech, D.; Deidun, A., and Gauci, A., 2020. A spatial prioritisation exercise for marine spatial planning implementation within MPA MT105 of the Maltese Islands. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 790-796. Coconut Creek (Florida), ISSN 0749-0208. Anthropogenic maritime drivers exert pressures on ecological components, including assemblages of high conservation importance as Posidonia oceanica seagrass meadows and maerl beds. These drivers also influence and interact with each other and can generate user-to-user conflicts, which traditionally have justified the need for a holistic Marine Spatial Planning approach. Through the use of the Driver Pressure State Impact Risk (DPSIR) framework and related decision-support tools, we generated both cumulative marine habitat vulnerability maps and cumulative marine user-user conflicts maps within MPA MT105 of the Maltese Islands. These maps are intended to serve as decision - support tools for national policy- makers given that Malta is required to deliver its management plans for some of its marine Natura 2000 sites by the end of 2019. [ABSTRACT FROM AUTHOR]

The aim of this research was to assess marine litter abundance and its effects on the benthic fauna in an area of the central Mediterranean Sea exploited by fisheries using fish aggregating devices (FAD). The study was carried out by means of a remotely-operated vehicle (ROV). Derelict fishing gear, mainly FAD ropes, represented the main source of marine debris, contributing 96.2% to the overall litter. About 47% of debris items (mostly FAD ropes) entangled colonies of the protected black coral Leiopathes glaberrima. The results of this research will assist in the monitoring of "impact/harm" to the coral and other benthic communities, as recommended by the Marine Strategy Framework Directive and by the Integrated Monitoring and Assessment Programme. Preventive and mitigation measures (i.e., biodegradable fishing gear, onboard technology to locate and retrieve gear, reception and/or payment for old/retrieved gear, and introduction of no-take zones) to reduce the problem are discussed. Unlabelled Image • Seafloor marine litter was quantified in an area heavily exploited by FADs fishery. • Debris density recorded, from 250 to 400 m depth, was 4.63 items/100 m2. • Derelict fishing gear, mainly FAD ropes, represented 96.2% of the overall litter. • Marine litter severely impacted habitats and species of conservation concern. • The black coral Leiopathes glaberrima resulted severely damaged by entanglement. [ABSTRACT FROM AUTHOR]

Four sandy beaches on the island of Malta in the Central Mediterranean were regularly sampled for Large MicroPlastic (LMP) particles having a diameter between 1 mm and 5 mm, at stations located at the waterline and 10 m inshore. The 10975 extracted LMP particles were characterised (dimensions, surface roughness, colour) through unaided visual observation, microscopic analyses, and an algorithm developed within the current study. Two-thirds of the isolated particles were smooth and the majority of these belonged to the grey-white colour category, with a low degree of opaqueness and discolouration, and a high degree of transparency, suggesting that these were dominated by low-density polyethylene LMPs. Conflicting evidence concerning the relative residence time of the isolated LMPs within seawater emerged from the colour and contour roughness determination, although an abundance of primary LMPs (production pellets) within our sample might have been responsible for the low contour roughness results obtained. Roughly six times as many particles were recorded within the inshore sampling stations as the particles recorded at the waterline stations. The developed algorithm performed very well when the dimension and colour parameter values it delivered were compared with those obtained by microscopic analyses. • No universal methodology of high validity for analysing isolated microplastics. • Use of image processing techniques to automatically extract parameters for LMPs. • Make the process less time-consuming and removes subjectivity. • Samples collected from a number of popular beaches around the island of Malta. • Algorithm performed well in determining the dimensions and colour of the LMPs. [ABSTRACT FROM AUTHOR]

Introduction: Drug–drug interactions (DDIs) have potential to cause patient harm, including lowering therapeutic efficacy. This study aimed to (i) determine the prevalence of potential DDIs (pDDIs); clinically relevant DDIs (cDDIs), that is, DDIs that could lead to patient harm, taking into account a patient's individual clinical profile, drug effects and severity of potential harmful outcome; and subsequent actual harm among hospitalized patients and (ii) examine the impact of transitioning from paper-based medication charts to electronic medication management (eMM) on DDIs and patient harms. Methods: This was a secondary analysis of the control arm of a controlled pre-post study. Patients were randomly selected from three Australian hospitals. Retrospective chart review was conducted before and after the implementation of an eMM system, without accompanying clinical decision support alerts for DDIs. Harm was assessed by an expert panel. Results: Of 1186 patient admissions, 70.1% (n = 831) experienced a pDDI, 42.6% (n = 505) a cDDI and 0.9% (n = 11) an actual harm in hospital. Of 15,860 pDDIs identified, 27.0% (n = 4285) were classified as cDDIs. The median number of pDDIs and cDDIs per 10 drugs were 6 [interquartile range (IQR) 2–13] and 0 (IQR 0–2), respectively. In cases where a cDDI was identified, both drugs were 44% less likely to be co-administered following eMM (adjusted odds ratio 0.56, 95% confidence interval 0.46–0.73). Conclusion: Although most patients experienced a pDDI during their hospital stay, less than one-third of pDDIs were clinically relevant. The low prevalence of harm identified raises questions about the value of incorporating DDI decision support into systems given the potential negative impacts of DDI alerts. [ABSTRACT FROM AUTHOR]

Terrestrial, freshwater, and marine ecosystems are connected via multiple biophysical and ecological processes. Identifying and quantifying links among ecosystems is necessary for the uptake of integrated conservation actions across realms. Such actions are particularly important for species using habitats in more than one realm during their daily or life cycle. We reviewed information on the habitats of 2,408 species of European conservation concern and found that 30% of the species use habitats in multiple realms. Transportation and service corridors, which fragment species habitats, were identified as the most important threat impacting ∼70% of the species. We examined information on 1,567 European Union (EU) conservation projects funded over the past 25 years, to assess the adequacy of efforts toward the conservation of "multi‐realm" species at a continental scale. We discovered that less than a third of multi‐realm species benefited from projects that included conservation actions across multiple realms. To achieve the EU's conservation target of halting biodiversity loss by 2020 and effectively protect multi‐realm species, integrated conservation efforts across realms should be reinforced by: (1) recognizing the need for integrated management at a policy level, (2) revising conservation funding priorities across realms, and (3) implementing integrated land‐freshwater‐sea conservation planning and management. [ABSTRACT FROM AUTHOR]

The Mediterranean area, from southern Balkans to western Maghreb, is inhabited by the Potamon subgenus Euthelphusa, with three currently recognised species. The Maghrebian species P. (E.) algeriense is isolated from other Potamon species by the Mediterranean Sea and the Sahara Desert, and nearly no molecular data are currently available for this taxon. Present study investigated the mtDNA and nuDNA diversity in Potamon algeriense s.l. with the aims of exploring its molecular diversity pattern throughout its known distribution range, and testing the possible presence of cryptic taxa currently lumped under this binomen. The phylogenetic and DNA taxonomy analyses showed the presence of two well‐supported clades of species rank within P. algeriense s.l, with an eastern clade including the populations from Tunisia and Numidia, and a western, highly structured clade including the populations from central Algeria and Morocco. In agreement with a typical Maghrebian biogeographic pattern, the distribution of these two species shows a clear east–west divide, with a disjunction zone located in Kabylia, and a strong link between molecular diversity and segregation within different hydrographical basins is evident. The Maghreb thus proved to host an unexpectedly high genetic diversity of, and to constitute a biodiversity hot‐spot for, the Potamon subgenus Euthelphusa. In the light of the existence of two well‐characterised species currently lumped under P. algeriense s.l., and of their noteworthy molecular structuring, the status of Maghrebian Potamon populations should be re‐assessed for both the species present in the area, which are to be considered as independent management units. [ABSTRACT FROM AUTHOR]

A prerequisite for ecotourism development is the presence of natural environments, normally exhibited in protected areas, which serve as ecotourism venues. Little attention has been given to Mediterranean islands in terms of ecotourism. In this paper, nine islands in the central Mediterranean region were studied through a case study approach to investigate their potential as ecotourism destinations, taking into account the presence of protected areas and related aspects, including spatial dimensions and quality, to fulfil ecotourists. Larger islands with higher population densities were found to experience habitat fragmentation, and protected areas were thus in some cases relatively small and dispersed. In contrast, smaller, less populated islands were found to be more ideal ecotourism destinations due to limited anthropogenic impact and their capacity to fulfil the expectations of the 'true specialists', also known as 'hard ecotourists'. Quality of ecotourism venues was found to affect ecotourist satisfaction. Ideal ecotourism sites on heavily impacted islands were found on the island periphery, in coastal and marine locations, with marine ecotourism serving as the ideal ecotourism product on such islands. [ABSTRACT FROM AUTHOR]

Tetrodotoxin is a naturally occurring potent neurotoxin, widely distributed in marine animals, including a number of members of the Tetraodontidae fish family (e.g. Lagocephalus sceleratus, the silver-cheeked toadfish), a marine invasive species native of the Indo-Pacific region which is increasingly being reported from the Mediterranean. Various human fatalities have been documented globally as a result of intoxication through tetrodotoxin, but these have rarely been associated with the ingestion of octopus flesh. We hereby report the case of two patients from the Maltese Islands (central Mediterranean) who presented symptoms consistent with neurotoxicity, following the consumption of the well-cooked flesh of the common octopus. Both patients required supportive care, until complete recovery within a few days, with one of whom requiring intensive care. The reported cases of neuromuscular disturbances following the consumption of octopus flesh is highly suggestive of neurotoxicity due to tetrodotoxin poisoning, the first such cases documented for the Mediterranean waters, although alternative scenarios are also postulated in this study due to the lack of definite evidence for the TTX poisoning, including the release of histamine by psychrotrophic bacteria or the accumulation of HAB-related toxins. The postulated TTX intoxication mechanism involves predation by Octopus vulgaris, the common octopus or 'scuttle', on a toxic marine species harbouring tetrodotoxin. [ABSTRACT FROM AUTHOR]

Simple Summary: Biological invasions are one of the most urgent issues to be managed in order to avoid the risk of endemic biodiversity loss. Among management strategies, the monitoring of non-native species is needed to make appropriate decisions. To complement the standard monitoring, citizen science is increasingly being used. Within citizen science, the approach of Local Ecological Knowledge (LEK) proved to be useful in the monitoring of non-native species. A LEK survey was carried out in 10 Sicilian and Maltese Natura 2000 sites and was addressed to local fishers and SCUBA divers in order to help in the early detection of non-native species. The occurrence of 24 selected marine non-native species was investigated through the use of a questionnaire for the LEK survey. Potential hotspot areas of invasion were identified by using six indicators: the occurrence of newly introduced nonindigenous species, the cumulative impacts of invasive alien species (CIMPAL), and the relative importance of species on the cumulative impacts (D1, D2, D3, and D4). The respondents confirmed the presence of 22 species since 2000 and reported 10 new ones in the investigated areas. The highest CIMPAL values were observed in Sicily in the Fondali dell'isola di Capo Passero and in the MPA Isole Pelagie and the lowest on the western coast of Malta (MT0000101, MT0000102, MT0000103, and MT0000104). The four top-priority species according to indicators D1–D4 were the algae Caulerpa cylindracea and C. taxifolia and the fishes Siganus luridus and S. rivulatus. The management of biological invasions is among the most urgent of global challenges and requires a significant monitoring effort to obtain the information needed to take the appropriate decisions. To complement standard monitoring, citizen science is increasingly being used. Within citizen science, the approach of collecting and investigating Local Ecological Knowledge (LEK) proved to be useful in the monitoring of non-native species. A LEK survey was carried out in 10 Sicilian and Maltese Natura 2000 sites in order to help in the early detection of non-native species. The survey was addressed to local fishers and SCUBA divers in order to investigate the occurrence of 24 selected marine non-native species and to identify potential hotspot areas of invasion through the use of six indicators: the occurrence of newly introduced nonindigenous species, the cumulative impacts of invasive alien species (CIMPAL) and the relative importance of species on the cumulative impacts (D1, D2, D3, and D4). The respondents confirmed the presence of 22 species since the year 2000 and reported 10 new ones registered in the investigated areas. The highest CIMPAL value was observed in two Sicilian Natura 2000 sites (ITA090028 and ITA040014) and the lowest on the western coast of Malta (MT0000101, MT0000102, MT0000103, and MT0000104) The four top-priority species according to indicators D1–D4 were Caulerpa cylindracea, C. taxifolia, Siganus luridus and S. rivulatus. The study produced a valid and useful scientific output to suggest and address management strategies to monitor the establishment of the non-native species. [ABSTRACT FROM AUTHOR]

The author reflects on the hospitals and medical facilities in East Kimberley, Western Australia (WA). She mentions the services offered by three hospitals in East Kimberley including Kununurra District Hospital, Wyndham Hospital and Halls Creek Hospital, Pharmaceutical Benefits Scheme (PBS) reform in Kununurra in 2011 and authorisation to supply medicines under Section 100 to Halls Creek. She also mentions medication reconciliation procedure in Kununurra and health international travellers.

Remote-sensing ocean colour studies have already been used to determine coastal water quality, coastal biodiversity, and nutrient availability. In recent years, Unmanned Aerial Vehicles (UAVs) equipped with multispectral sensors, originally designed for agriculture applications, have also enabled water-quality studies of coastal waters. However, since the sea surface is constantly changing, commonly used photogrammetric methods fail when applied to UAV images captured over water areas. In this work, we evaluate the applicability of a five-band multispectral sensor mounted on a UAV to derive scientifically valuable water parameters such as chlorophyll-a (Chl-a) concentration and total suspended solids (TSS), including a new Python workflow for the manual generation of an orthomosaic in aquatic areas exclusively based on the sensor's metadata. We show water-quality details in two different sites along the Maltese coastline on the centimetre-scale, improving the existing approximations that are available for the region through Sentinel-3 OLCI imagery at a much lower spatial resolution of 300 m. The Chl-a and TSS values derived for the studied regions were within the expected ranges and varied between 0 to 3 mg/m3 and 10 to 20 mg/m3, respectively. Spectral comparisons were also carried out along with some statistics calculations such as RMSE, MAE, or bias in order to validate the obtained results. [ABSTRACT FROM AUTHOR]

The rapid, global spread of COVID-19, and the measures intended to limit or slow its propagation, are having major impacts on diverse sectors of society. Notably, these impacts are occurring in the context of other anthropogenic-driven threats including global climate change. Both anthropogenic stressors and the COVID-19 pandemic represent significant economic challenges to aquaculture systems across the globe, threatening the supply chain of one of the most important sources of animal protein, with potential disproportionate impacts on vulnerable communities. A web survey was conducted in 47 countries in the midst of the COVID-19 pandemic to assess how aquaculture activities have been affected by the pandemic, and to explore how these impacts compare to those from climate change. A positive correlation between the effects of the two categories of drivers was detected, but analysis suggests that the pandemic and the anthropogenic stressors affect different parts of the supply chain. The immediate measurable reported losses varied with aquaculture typology (land vs. marine, and intensive vs. extensive). A comparably lower impact on farmers reporting the use of integrated multitrophic aquaculture (IMTA) methods suggests that IMTA might enhance resilience to multiple stressors by providing different market options under the COVID-19 pandemic. Results emphasize the importance of assessing detrimental effects of COVID-19 under a multiple stressor lens, focusing on areas that have already locally experienced economic loss due to anthropogenic stressors in the last decade. Holistic policies that simultaneously address other ongoing anthropogenic stressors, rather than focusing solely on the acute impacts of COVID-19, are needed to maximize the long-term resilience of the aquaculture sector. [ABSTRACT FROM AUTHOR]

The marbled crayfish (Procambarus virginalis) represents a very recently evolved parthenogenetic freshwater crayfish species that has invaded diverse habitats in Europe and in Madagascar. However, population genetic analyses have been hindered by the homogeneous genetic structure of the population and the lack of suitable tools for data analysis. We have used whole-genome sequencing to characterize reference specimens from various known wild populations. In parallel, we established a whole-genome sequencing data analysis pipeline for the population genetic analysis of nearly monoclonal genomes. Our results provide evidence for systematic genetic differences between geographically separated populations and illustrate the emerging differentiation of the marbled crayfish genome. We also used mark-recapture population size estimation in combination with genetic data to model the growth pattern of marbled crayfish populations. Our findings uncover evolutionary dynamics in the marbled crayfish genome over a very short evolutionary timescale and identify the rapid growth of marbled crayfish populations as an important factor for ecological monitoring. Olena Maiakovska et al. provide whole-genome sequencing of the parthenogenetic and invasive marbled crayfish and develop a computational framework for data analysis of monoclonal genomes. These data and methodology allow the authors to demonstrate genetic separation between two populations and provide the first size estimate for a marbled crayfish colony, which they used to model population growth patterns. [ABSTRACT FROM AUTHOR]

Managing invasive alien species is particularly challenging in the ocean mainly because marine ecosystems are highly connected across broad spatial scales. Eradication of marine invasive species has only been achieved when species were detected early, and management responded rapidly. Generalized approaches, transferable across marine regions, for prioritizing actions to control invasive populations are currently lacking. Here, expert knowledge was elicited to prioritize 11 management actions for controlling 12 model species, distinguished by differences in dispersion capacity, distribution in the area to be managed, and taxonomic identity. Each action was assessed using five criteria (effectiveness, feasibility, acceptability, impacts on native communities, and cost), which were combined in an 'applicability' metric. Raising public awareness and encouraging the commercial use of invasive species were highly prioritized, whereas biological control actions were considered the least applicable. Our findings can guide rapid decision-making on prioritizing management options for the control of invasive species especially at early stages of invasion, when reducing managers' response time is critical. Unlabelled Image • None of the actions was considered ideal for the management of invasive species. • Public awareness and commercial use of invasive species were highly prioritized. • Biological control actions were considered the least applicable. • "Doing nothing" ranked high but should be considered with great caution. [ABSTRACT FROM AUTHOR]

The immune system of the sea urchin species Paracentrotus lividus is highly complex and, as yet, poorly understood. P. lividus coelomocytes mediate immune response through phagocytosis and encapsulation of non-self particles, in addition to the production of antimicrobial molecules. Despite this understanding, details of exactly how these processes occur and the mechanisms which drive them are still in need of clarification. In this study, we show how the bacterial lipopolysaccharides (LPS) is able to induce a stress response which increases the levels of the heat shock proteins HSP70 and HSP90 only a few hours after treatment. This study also shows that LPS treatment increases the expression of the β-thymosin-derivated protein paracentrin, the precursor of antimicrobial peptides. • Immune response in Paracentrotus lividus after stimulation with LPS. • Echinoderm immune response and HSP90 and HSP70 expression. • β-Thymosin modulation following LPS treatment. [ABSTRACT FROM AUTHOR]

Abstract: The impact of recreational fishing on fish stocks remains largely unknown, as this is inherently difficult to monitor, especially in areas such as the Mediterranean Sea where many species are targeted using a variety of fishing gears and techniques. This study attempts to complement existing data sets and construct the profile of recreational fisheries in the EU‐Mediterranean countries using videos publicly available on social media. A total of 1526 video records were selected, featuring the capture of 7799 fish specimens. The results show recreational fishing is multispecies in nature (26 species contributed to >80% % of the most numerically important species caught) and exhibits a spatially homogeneous pattern, with differences in species composition being mostly dependent on the fishing technique used rather than on the country. Such findings fill an important knowledge gap on recreational fishing activities, and the methodology provides an innovative approach to gather statistics on data‐poor thematic areas that can potentially complement other data sets, such as the EU Data Collection Multi‐Annual Programme. [ABSTRACT FROM AUTHOR]

We studied the relationships between sediment industrial pollutants concentrations, sediment characteristics and the dinoflagellate cyst abundance within a coastal lagoon by investigating a total of 55 sampling stations within the Bizerte lagoon, a highly anthropized Mediterranean ecosystem. The sediment of Bizerte lagoon is characterized by a high dinocyst abundance, reaching a maximum value of 2742 cysts·g − 1 of dry sediment. The investigated cyst diversity was characterized by the presence of 22 dominant dinocyst morphotypes belonging to 11 genera. Two dinoflagellate species dominated the assemblage: Alexandrium pseudogonyaulax and Protoperidinium claudicans , representing 29 to 89% and 5 to 38% of the total cyst abundance, respectively, depending on the station. Seven morphotypes belonging to potentially toxic species were detected, including Alexandrium minutum , A. pseudogonyaulax , Alexandrium catenella/tamarense species complex , Lingulodinium polyedrum , Gonyaulax cf. spinifera complex, Prorocentrum micans and Protoceratium reticulatum . Pearson correlation values showed a positive correlation (α = 0.05) between cyst abundance and both water content and fine silt sediment content. Clustering revealed that the highest abundance of cysts corresponds to stations presenting the higher amounts of heavy metals. The simultaneous autoregressive model (SAM) highlighted a significant correlation (α = 0.05) between cyst accumulation and two main factors: sediment water content and sediment content for several heavy metals, including Hg, Cd, Cu, Ni and Cr. These results suggest that the degree of heavy metal pollution could influence cyst accumulation patterns. [ABSTRACT FROM AUTHOR]

The expansion of invasive non-indigenous species in the Mediterranean is generating an increasing concern about biodiversity protection and human health, with European countries being solicited to apply early warning measures in such circumstances. The recent expansion of the hazardous fish Lagocephalus sceleratus in the Straits of Sicily, the subsequent actions adopted to manage the risk and the feedback received from the public are herein presented, as an example of the interaction between experts and the public in promoting scientific citizenship through an ad hoc action. A rapid increase in media reports related to L. sceleratus had been registered after the launch of the early warning campaign as part of a scientific and health risk communication strategy, and seven new records of this species have emerged shortly after. This study represents a useful contribution to the further bridging of the science-policy gap. [ABSTRACT FROM AUTHOR]

The much-publicised increased resistance of pathogenic bacteria to conventional antibiotics has focused research effort on the characterization of new antimicrobial drugs. In this context, antimicrobial peptides (AMPs) extracted from animals are considered a promising alternative to conventional antibiotics. In recent years, freshwater crayfish species have emerged as an important source of bioactive compounds. In fact, these invertebrates rely on an innate immune system based on cellular responses and on the production of important effectors in the haemolymph, such as AMPs, which are produced and stored in granules in haemocytes and released after stimulation. These effectors are active against both Gram-positive and Gram-negative bacteria. In this review, we summarise the recent progress on AMPs isolated from the several species of freshwater crayfish and their prospects for future pharmaceutical applications to combat infectious agents. [Display omitted] • Antimicrobial peptides (AMPs), a potential natural alternative to conventional antibiotics. • Freshwater crayfish as an important source of AMPs. • Potential applications of AMPs isolated from freshwater crayfish. [ABSTRACT FROM AUTHOR]

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., (Copyright © 2018. Published by Elsevier Ltd.)

[This corrects the article DOI: 10.7717/peerj.3954.].

The Mediterranean Sea is home to over 2/3 of the world's charter boat traffic and hosts an estimated 1.5 million recreational boats. Studies elsewhere have demonstrated marinas as important hubs for the stepping-stone transfer of non-indigenous species (NIS), but these unique anthropogenic, and typically artificial habitats have largely gone overlooked in the Mediterranean as sources of NIS hot-spots. From April 2015 to November 2016, 34 marinas were sampled across the following Mediterranean countries: Spain, France, Italy, Malta, Greece, Turkey and Cyprus to investigate the NIS presence and richness in the specialized hard substrate material of these marina habitats. All macroinvertebrate taxa were collected and identified. Additionally, fouling samples were collected from approximately 600 boat-hulls from 25 of these marinas to determine if boats host diverse NIS not present in the marina. Here, we present data revealing that Mediterranean marinas indeed act as major hubs for the transfer of marine NIS, and we also provide evidence that recreational boats act as effective vectors of spread. From this wide-ranging geographical study, we report here numerous new NIS records at the basin, subregional, country and locality level. At the basin level, we report three NIS new to the Mediterranean Sea ( Achelia sawayai sensu lato , Aorides longimerus , Cymodoce aff. fuscina ), and the re-appearance of two NIS previously known but currently considered extinct in the Mediterranean ( Bemlos leptocheirus, Saccostrea glomerata ). We also compellingly update the distributions of many NIS in the Mediterranean Sea showing some recent spreading; we provide details for 11 new subregional records for NIS ( Watersipora arcuata , Hydroides brachyacantha sensu lato and Saccostrea glomerata now present in the Western Mediterranean; Symplegma brakenhielmi , Stenothoe georgiana , Spirobranchus tertaceros sensu lato , Dendostrea folium sensu lato and Parasmittina egyptiaca now present in the Central Mediterranean, and W. arcuata , Bemlos leptocheirus and Dyspanopeus sayi in the Eastern Mediterranean). We also report 51 new NIS country records from recreational marinas: 12 for Malta, 10 for Cyprus, nine for Greece, six for Spain and France, five for Turkey and three for Italy, representing 32 species. Finally, we report 20 new NIS records (representing 17 species) found on recreational boat-hulls (mobile habitats), not yet found in the same marina, or in most cases, even the country. For each new NIS record, their native origin and global and Mediterranean distributions are provided, along with details of the new record. Additionally, taxonomic characters used for identification and photos of the specimens are also provided. These new NIS records should now be added to the relevant NIS databases compiled by several entities. Records of uncertain identity are also discussed, to assess the probability of valid non-indigenous status., Competing Interests: The authors declare that there are no competing interests.