Jordi Grinyó
email: jordigrinyo85@gmail.com

Claudio Lo Iacono

Martina Pierdomenico

Suzanne Conlon

Guillem Corbera

Eulàlia Gràcia

Evidences of human impact on megabenthic assemblages of bathyal sediments in the Alboran Sea (western Mediterranean)

Keywords: Mediterranean Sea, vulnerable marine ecosystems, megabenthos, soft sediments, bottom trawling, marine litter

de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

The present-day advances in underwater technologies eased the access to scientific Remotely Operated Vehicles (ROVs), Autonomous Underwater Vehicles (AUVs) and high-frequency imaging systems, able to operate at high depths during increasingly long acquisition periods [START_REF] Wynn | Autonomous Underwater Vehicles (AUVs): Their past, present and future contributions to the advancement of marine geoscience[END_REF][START_REF] Aguzzi | New High-Tech Flexible Networks for the Monitoring of Deep-Sea Ecosystems[END_REF][START_REF] Price | Using 3D photogrammetry from ROV video to quantify cold-water coral reef structural complexity and investigate its influence on biodiversity and community assemblage[END_REF][START_REF] Bo | Unveiling the deep biodiversity of the Janua Seamount (Ligurian Sea): first Mediterranean sighting of the rare Atlantic bamboo coral Chelidonisis aurantiaca Studer, 1890[END_REF]. These advances generate a sudden expansion on the deep-sea benthic ecology studies, and related physical processes based on image analysis and highresolution acoustic mapping (e.g. [START_REF] Benoist | A generalised volumetric method to estimate the biomass of photographically surveyed benthic megafauna[END_REF][START_REF] Corbera | Ecological characterisation of a Mediterranean cold-water coral reef: Cabliers Coral Mound Province (Alboran Sea, western Mediterranean)[END_REF]. In parallel, the technological expansion in marine sciences enhanced the awareness that human-related activities exert a strong and pervasive impact on deep-sea ecosystems, with a detrimental effect on habitat complexity and biodiversity (de [START_REF] De Moura Neves | Deep-water bamboo coral forests in a muddy Arctic environment[END_REF][START_REF] Bouden | Little Evidence of Benthic Community Resilience to Bottom Trawling on Seamounts After 15 Years[END_REF].

Image-based investigations of deep-sea habitats were mainly focused on benthic communities or key structuring species occurring on hard substrates [START_REF] Mortensen | Deep-water corals and their habitats in The Gully, a submarine canyon off Atlantic Canada[END_REF][START_REF] Althaus | Impacts of bottom trawling on deep-coral ecosystems of seamounts are long-lasting[END_REF][START_REF] Price | Using 3D photogrammetry from ROV video to quantify cold-water coral reef structural complexity and investigate its influence on biodiversity and community assemblage[END_REF], while similar studies on deep-sea sedimentary settings are scarce [START_REF] Robert | Surface-sediment bioturbation quantified with cameras on the NEPTUNE Canada cabled observatory[END_REF][START_REF] De Leo | Bottom trawling and oxygen minimum zone influences on continental slope benthic community structure off Vancouver Island (NE Pacific)[END_REF]. This represents a significant knowledge gap, considering that deep-sea sediments are among the most widespread benthic habitats in the world, covering vast areas of continental shelves, slopes and abyssal plains [START_REF] Gray | Species richness of marine soft sediments[END_REF]. Deep-sea sedimentary environments have been traditionally considered as barren fields sparsely populated by megabenthic organisms [START_REF] Jones | Megabenthic ecology of the deep Faroe-Shetland channel: A photographic study[END_REF]. However, in specific areas, deep-sea sedimentary floors have been shown to host three-dimensional complex megabenthic assemblages, such as sponge grounds or sessile anthozoan aggregations (de [START_REF] De Moura Neves | Deep-water bamboo coral forests in a muddy Arctic environment[END_REF]Maldonado et al., 2015). These assemblages locally enhance biomass and act as biodiversity hotspots, as they provide habitat for a large variety of associated species, including a wide range of species of economic interest [START_REF] Maynou | Effects of trawling on fish and invertebrates from deep-sea coral facies of Isidella elongata in the western Mediterranean[END_REF][START_REF] De Moura Neves | Deep-water bamboo coral forests in a muddy Arctic environment[END_REF]Maldonado et al., 2017;[START_REF] Mastrototaro | Isidella elongata ( Cnidaria : Alcyonacea ) facies in the western Mediterranean Sea: visual surveys and descriptions of its ecological role[END_REF][START_REF] Pierdomenico | Effects of trawling activity on the bamboo-coral Isidella elongata and the sea pen Funiculina quadrangularis along the Gioia Canyon (Western Mediterranean, southern Tyrrhenian Sea)[END_REF].

Deep-sea benthic communities are generally composed of fragile organisms having very slow recovering rates [START_REF] Bouden | Little Evidence of Benthic Community Resilience to Bottom Trawling on Seamounts After 15 Years[END_REF]. Consequently, the impact of overexploiting human activities produce extremely long-lasting degrading effects [START_REF] Jobstvogt | Twenty thousand sterling under the sea: Estimating the value of protecting deep-sea biodiversity[END_REF][START_REF] Vanreusel | Threatened by mining, polymetallic nodules are required to preserve abyssal epifauna[END_REF][START_REF] Bouden | Little Evidence of Benthic Community Resilience to Bottom Trawling on Seamounts After 15 Years[END_REF].

In 2006, the need to preserve Vulnerable Marine Ecosystems (VMEs) from the negative impacts caused by human activities, led to the development of specific management and conservation measures to prevent their degradation (UNGA, 2007).

To achieve this goal, several international strategies, such as the "International guideline for the management of the deep-sea fisheries in the high seas" [START_REF] Fao | Report of the technical consultation on international guidelines for the management of deep-sea fisheries in the high seas[END_REF] or the EU's Marine Strategy Directive (2008/56/CE), have been developed during the last decade. Deep-sea soft sedimentary environments of the Mediterranean Sea host several VMEs, mainly represented by the isidid Isidella elongata and the pennatulaceans Funiculina quadrangularis and Kophobelemnon stelliferum.

Amongst the many anthropogenic impacts on the marine environment, bottom trawling is the widest spread physical disturbance in the world's seabed [START_REF] Watling | Deep-sea trawling must be banned[END_REF][START_REF] Hiddink | Global analysis of depletion and recovery of seabed biota after bottom trawling disturbance[END_REF]. Impacts associated to bottom trawling include removal or damage to epibenthic fauna, reduction of habitat complexity and alteration of sedimentary and geochemical processes (e.g. De [START_REF] De Leo | Bottom trawling and oxygen minimum zone influences on continental slope benthic community structure off Vancouver Island (NE Pacific)[END_REF][START_REF] Hiddink | Global analysis of depletion and recovery of seabed biota after bottom trawling disturbance[END_REF][START_REF] Paradis | Organic matter contents and degradation in a highly trawled area during fresh particle inputs (Gulf of Castellammare, southwestern Mediterranean)[END_REF]. With bottom trawling progressively expanding to deeper environments, VMEs associated to sedimentary bottoms have undergone a vast decimation [START_REF] Sardà | An introduction to Mediterranean deep-sea biology[END_REF][START_REF] Gerovasileiou | Updating the distribution status of the critically endangered bamboo coral Isidella elongata (Esper, 1788) in the deep Eastern Mediterranean Sea[END_REF][START_REF] Pusceddu | Chronic and intensive bottom trawling impairs deep-sea biodiversity and ecosystem functioning[END_REF], restricting their distribution to isolated regions or areas inaccessible to trawlers, such as sub-vertical walls or regions surrounded by rocky outcrops [START_REF] Bo | Persistence of Pristine Deep-Sea Coral Gardens in the Mediterranean Sea (SW Sardinia)[END_REF][START_REF] Pierdomenico | Effects of trawling activity on the bamboo-coral Isidella elongata and the sea pen Funiculina quadrangularis along the Gioia Canyon (Western Mediterranean, southern Tyrrhenian Sea)[END_REF].

Marine litter represents a further extremely pervasive and fast-growing anthropogenic pollution affecting the world's oceans (Bergmann et al., 2015). Specifically, benthic marine debris, defined as the macro-litter that settles on the seafloor [START_REF] Spengler | Methods applied in studies of benthic marine debris[END_REF], can damage benthic organisms through entanglement or coverage [START_REF] Pham | Marine litter distribution and density in European seas, from the shelves to deep basins[END_REF]Bergman et al., 2015). Litter and especially plastic debris are a considerable source of persistent organic pollutants and chemical additives, which are toxic to marine species [START_REF] Rochman | Ingested plastic transfers hazardous chemicals to fish and induces hepatic stress[END_REF]. The breakdown products of plastic, the so-called microplastics, are proven to be ingested by a variety of organisms, with potential ecotoxicological effects still poorly assessed [START_REF] Browne | Microplastic moves pollutants and additives to worms, reducing functions linked to health and biodiversity[END_REF][START_REF] Carreras-Colom | Spatial occurrence and effects of microplastic ingestion on the deep-water shrimp Aristeus antennatus[END_REF]Cau et al., 2019a).

Most of the information regarding VMEs of deep-sea sediments derives from invasive sampling gears (e.g. experimental trawling, epi-benthic sledge) [START_REF] Gili | Types of bottoms and benthic cnidaria from the trawling grounds (Littoral and Bathyal off Catalonia (NE Spain))[END_REF][START_REF] Maynou | Effects of trawling on fish and invertebrates from deep-sea coral facies of Isidella elongata in the western Mediterranean[END_REF][START_REF] Mastrototaro | A facies of Kophobelemnon (Cnidaria, Octocorallia) from Santa Maria di Leuca coral province (Mediterranean Sea)[END_REF], which despite providing relevant information on species occurrence, deliver limited knowledge on sessile taxa abundance, assemblage composition, habitat characteristics and their state of conservation [START_REF] Soltwedel | Bathymetric patterns of megafaunal assemblages from the arctic deep-sea observatory HAUSGARTEN[END_REF][START_REF] Chimienti | ROV vs trawling approaches in the study of benthic communities: the case of Pennatula rubra (Cnidaria: Pennatulacea)[END_REF]. Recently, several imagebased studies carried out in the canyon heads of the Gulf of Lion and Tyrrhenian Sea, and the open slope of the Balearic archipelago, have provided new insights on the VMEs of sedimentary environments, highlighting in most cases their poor conservation status (e.g. [START_REF] Fabri | Megafauna of vulnerable marine ecosystems in French mediterranean submarine canyons: Spatial distribution and anthropogenic impacts[END_REF][START_REF] Mastrototaro | Isidella elongata ( Cnidaria : Alcyonacea ) facies in the western Mediterranean Sea: visual surveys and descriptions of its ecological role[END_REF][START_REF] Pierdomenico | Effects of trawling activity on the bamboo-coral Isidella elongata and the sea pen Funiculina quadrangularis along the Gioia Canyon (Western Mediterranean, southern Tyrrhenian Sea)[END_REF]. Overall, our knowledge of deep-sea assemblages located on soft bottoms is still limited and thus, it is urgent to improve our understanding of these VMEs in order to support sound conservation and management measures (Maldonado et al., 2015;[START_REF] Mastrototaro | First record of Protoptilum carpenteri (Cnidaria: Octocorallia: Pennatulacea) in the Mediterranean Sea[END_REF].

Based on the analyses of ROV footage collected within a depth range of 500-860 m, we aim at (1) characterizing the composition of deep megabenthic assemblages found on sedimentary bottoms of the Alboran Sea (western Mediterranean), and (2) quantify the effects of human activities on these assemblages, with a major focus on changes in habitat complexity and biodiversity caused by bottom trawling.

Material and Methods

The Alboran Sea

The Alboran Sea is the westernmost basin of the Mediterranean, which is enclosed between the Iberian Peninsula and the North Africa, connected to the Atlantic Ocean through the Straits of Gibraltar (Fig. 1). The Alboran Sea displays a relatively complex seafloor geomorphology, including three main sub-basins (i.e. West, East and South Alboran Basins) separated by the Alboran Ridge, a major NE-SW oriented structural high [START_REF] Muñoz | Alborán Basin, southern Spain-part I: geomorphology[END_REF][START_REF] Lo Iacono | The West Melilla cold water coral mounds, Eastern Alboran Sea: Morphological characterization and environmental context[END_REF][START_REF] Gràcia | Active Faulting offshore SE Spain (Alboran Sea): Implications for earthquake hazard assessment in the Southern Iberian Margin[END_REF][START_REF] Gràcia | Acoustic and seismic imaging of the active Adra Fault (NE Alboran Sea): In search for the source of the 1910 Adra Earthquake[END_REF][START_REF] Gràcia | Earthquake crisis unveils the growth of an incipient continental fault system[END_REF]Fig. 1). The shelf of the Alboran Sea displays a variable extension, from 3.5 to 12 km, and is bounded by the shelf edge at a depth of 100-115 m. The slope is 10 to 50 km wide and displays variable gradients, connecting to the base of slope at a depth between 575 and 1000 m, transitioning to the deep basins. The sediment dynamics of the margin are strongly controlled by the prevailing along-slope current regimes, which gave origin to large contourite deposits [START_REF] Ercilla | Significance of bottom currents in Deep-sea morphodynamics: An example from the Alboran Sea[END_REF], 2019, Juan et al., 2016). They are locally interrupted by turbidite fans, mass-wasting deposits and volcanic outcrops [START_REF] Muñoz | Alborán Basin, southern Spain-part I: geomorphology[END_REF][START_REF] Lo Iacono | Seafloor characterization and backscatter variability of the Almería Margin (Alboran Sea, SW Mediterranean) based on high-resolution acoustic data[END_REF][START_REF] Ercilla | Influence of along slope processes on modern turbidite systems and canyons in the Alboran Sea (southwestern Mediterranean)[END_REF].

The Alboran Sea is mainly characterized by a siliciclastic sedimentation controlled by the river sources, together with the aeolian inputs as the main source of terrigenous sediments [START_REF] Moreno | Saharan dust transport and high-latitude glacial climatic variability: The Alboran Sea record[END_REF]. Nevertheless, the high input of organic-rich sediments is associated to the relatively high-productivity of this basin, in contrast with the general oligotrophic characteristics of the Mediterranean Sea [START_REF] Oguz | Fueling plankton production by a meandering frontal jet: A case study for the Alboran sea (Western Mediterranean)[END_REF]. Phytoplankton primary productivity is mainly related to the local circulation pattern, controlled by the entrance of Atlantic surface waters into the Mediterranean and the development of anticyclonic gyres [START_REF] Sarhan | Upwelling mechanisms in the northwestern Alboran Sea[END_REF]. Oceanographic conditions in the Alboran Sea are strictly related to the interaction between Atlantic and Mediterranean water masses, which create a regional thermohaline circulation [START_REF] Vargas-Yáñez | How much is the western Mediterranean really warming and salting[END_REF]. The Atlantic waters (AW), warmer and less salty than Mediterranean ones (T∼15 °C, S∼36.2 psu, T~13.5 ºC S~38.4 psu, respectively), enter the Alboran Sea through the Straits of Gibraltar and flow within the first 150-200 m of the water column at a velocity of ∼50 to up to 150 cm•s -1 [START_REF] Millot | Circulation in the Mediterranean sea[END_REF]. The AW circulation is driven by two semi-permanent anticyclonic gyres: The Western Alboran Gyre and the Eastern Alboran Gyre [START_REF] Renault | Surface circulation in the Alborn Sea (western Mediterranean) inferred from remotely sensed data[END_REF]Fig. 1). Deeper than the AW, the colder and salty Mediterranean Water (T∼13.5 °C, S∼38.4 psu), named Levantine Intermediate Water (LIW), flows towards the Straits of Gibraltar at ∼10 cm•s -1 (García Lafuente et al., 1998) (Fig. 1). The LIW extends down to 600 -700 m and flows above the underlying high density western Mediterranean deep water (<12.7-l2°C, S∼38.40-38.52 psu), whose circulation is largely conditioned by the local physiography of the basin [START_REF] Millot | Another description of the Mediterranean Sea outflow[END_REF]. Despite the lack of exhaustive studies on the deep-sea benthic assemblages of sedimentary substrates in the Alboran Sea, muddy substrates in interspersed patches within hard frameworks of cold-water coral communities have been reported to host colonies of I. elongata and the pennatulacean K. stelliferum [START_REF] Hebbeln | Report and preliminary results of RV POSEIDON Cruise POS 385 "Cold-Water Corals of the Alboran Sea (western Mediterranean Sea)[END_REF].

The ROV video acquisition

A total of six dives were recorded during the oceanographic expedition "SHAKE", onboard the R/V "Sarmiento de Gamboa" (May-June, 2015) (SHAKE Cruise: CGL2011-3005-C02-02) (Fig. 1, Table 1). Dives were carried out with the ROV "Max-Rover", owned by the Hellenic Centre for Marine Research. It was equipped with a HD video camera (1920x1080 pixels), a manipulator arm for sampling tasks and two parallel laser beams (10 cm apart) that provided a reference scale to measure targets and define a fixed width of 1 m for the subsequent video analysis. ROV positioning was achieved by means of an ultra-short baseline (USBL) transponder mounted on the vehicle, which tracked their positioning every 3 seconds, approximately. Dives were conducted on both, northern and southern sectors of the eastern Alboran Sea between 500 and 860 m depth (Table 1), along three areas characterized by the occurrence of active faults: Carboneras Fault, North-South Faults, Al-Idrissi Fault [START_REF] Gràcia | Active Faulting offshore SE Spain (Alboran Sea): Implications for earthquake hazard assessment in the Southern Iberian Margin[END_REF][START_REF] Gràcia | Acoustic and seismic imaging of the active Adra Fault (NE Alboran Sea): In search for the source of the 1910 Adra Earthquake[END_REF][START_REF] Gràcia | Earthquake crisis unveils the growth of an incipient continental fault system[END_REF]Fig. 1). The ROV moved at a constant speed of ~0.3 knots. Along each dive, voucher organisms were collected to confirm the taxonomic identification determined in the image analyses. Sampled organisms were fixed and preserved in 10% formalin for further analyses, were identified with the support of taxonomic experts and a manual on deep megabenthic fauna of the Mediterranean Sea [START_REF] Fourt | Guide de la faune profonde de la mer Méditerranée. Explorations des roches et canyons sous-marins des côtes françaises[END_REF].

Video analysis

Quantitative video analysis was performed according to the methodology described in [START_REF] Grinyó | Diversity, distribution and population size structure of deep Mediterranean gorgonian assemblages (Menorca Channel, Western Mediterranean Sea)[END_REF], using the software Final Cut Pro 7 (Apple Inc.). When the ROV was stopped or moving in loops, sequences were removed to avoid over-estimation of megabenthic organisms' abundance and dive length. Where the ROV was too detached from the seafloor or suspended sediments prevented a clear view of the seafloor, sequences were considered unusable and discarded from analyses. ROV dives covered a total distance of 5842 m, of which 5521 m was considered suitable for post-processing video analysis, corresponding to 94.5% of the total footage. Video analysis was aimed at quantifying the encountered megabenthic organisms, the lebensspuren items (i.e. sedimentary forms produced by metazoans biological activity) (Fig. 2), trawl marks and marine litter. All these items were quantified within a width of 1 m (estimated from the laser beam distance). Lebensspuren was classified into four categories: furrows, mounds, holes and trail marks (Fig. 2). Litter items were categorized according to their composition into five classes: plastics debris (i.e. plastic bags, bottles, small plastic fragments), lost fishing gears (long-lines and nets), metal debris, glass bottles and clothes. Additionally, two categories of substratum were defined: untrawled and trawled bottoms. Sediment texture and seafloor gradients were not considered in the video analysis due to the homogeneity of these variables. Each observation (organism, trawl mark, lebensspuren, marine litter) was assigned a position within the dive, following the methodology described by [START_REF] Grinyó | Diversity, distribution and population size structure of deep Mediterranean gorgonian assemblages (Menorca Channel, Western Mediterranean Sea)[END_REF].

Data treatment

Megabenthic fauna occupancy and abundance

To measure megabenthic fauna occupancy (i.e. the frequency of occurrence in the set of sampling units) and abundance (i.e. the number of individuals per sampling unit) and to assess megabenthic assemblage composition, each dive was split into 2 m 2 sampling units (0.7 m width and 2.9 m long). A total of 1904 sampling units were obtained. Each sampling unit was characterized by the abundance of organisms, number of sessile megabenthic species, lebensspuren and litter items. On the basis of trawl mark presence, sampling units were classified as trawled or untrawled.

Sessile megabenthic assemblage composition

Sessile megabenthic assemblages, defined here as assemblages constituted by sessile and low motile invertebrates such as echinoderms [START_REF] Grinyó | Megabenthic assemblages in the continental shelf edge and upper slope of the Menorca Channel, Western Mediterranean Sea[END_REF], were identified based on species composition by means of a non-metric multidimensional scaling ordination (nMDS) of the sampling units, with species abundances being square root transformed, and ordination performed via a Bray-Curtis dissimilarity matrix. Adonis permutation multivariate analysis of variance and subsequent pairwise tests were used to test for significant differences amongst assemblages. The nMDS and adonis test were performed using the R-language function "metaMDS" and "Adonis", available in the vegan library of the R software platform [START_REF] Oksanen | vegan: Community Ecology Package. R package version 2[END_REF]. Species occurring less than 3 times were excluded from the nMDS analysis.

Influence of anthropogenic impacts

Anthropogenic impact was assessed by estimating the occurrence of trawl marks and the density and typology of litter in each sampling unit. The effect of human disturbance on megafauna was analyzed within dives by comparing the frequency of occurrence of each megabenthic species in trawled (sampling units where trawl-marks were present) and un-trawled (sampling units where trawl marks were absent) sampling units, with similar environmental conditions in terms of substrate and inclination. Furthermore, we quantified the variation in habitat complexity and diversity between trawled (dives were trawl marks were present) and untrawled (dives were trawl marks were absent) areas, by comparing lebensspuren abundance [START_REF] Gage | Why are there so many species in deep-sea sediments?[END_REF] and the variation in species turnover (beta-diversity) by means of a randomized species accumulation curve [START_REF] De Leo | Spatial scale-dependent habitat heterogeneity influences submarine canyon macrofaunal abundance and diversity off the Main and Northwest Hawaiian Islands[END_REF]. This statistical approach allows us to find the average species accumulation curve and its standard deviation from random permutations of data (n=100), eluding misrepresentation in the curves due to differences in species abundance and sampling effort [START_REF] Gotelli | Quantifying biodiversity: Procedures and pitfalls in the measurement and comparison of species richness[END_REF].

Megabenthic species, also including decapods and ichthyofauna, were considered to calculate the randomized species accumulation curve, although species that present positive phototactism were not considered (e.g. myctophids or squids). Randomized species accumulation curves were calculated with R-language function "specaccum", using the vegan library of the R software platform [START_REF] Oksanen | vegan: Community Ecology Package. R package version 2[END_REF].

Results

Description of physical characteristics along ROV dives

Dive lengths ranged between 168 m to 1700 m depth (Table 1). In all the dives, the seafloor was considered sub-horizontal and consisted of muddy sediments. A total of nine pockmarks were observed, one in dive 4 and eight in dive 5 (Table 1).

Pockmarks displayed a circular shape, with diameters ranging between 1.5 and 3 m and a maximum depth of ∼40-50 cm. No carbonate concretions nor fluid or gas release were observed within the pockmarks, suggesting that these features are currently inactive. The remaining species accounted for less than 5% of all observed organisms and occurred in less than 6% of sampling units (Table 2).

Sessile megabenthic assemblage composition

Three megabenthic assemblages, distributed along the six ROV dives, could be identified in the nMDS: two monospecific assemblages composed by few colonies of the pennatulaceans K. stelliferum and F. quadrangularis respectively, and a multispecific group composed of I. elongata (28%), A. oligopodus (25%), T. muricata (18%), H. coronata (9%), L. phalangium (8%), M. intestinalis (8%) and Cerianthus membranaceus (4%) (Fig. 4). The Adonis test and subsequent pairwise test revealed that all three assemblages were significantly different (p<0.001) from one another.

Distribution of anthropogenic impacts

Marine litter was observed in all the ROV dives, except dive 6 (Table 3). Overall, 44 items were found, with plastics debris being the most abundant component (46%), followed by lost fishing gears (41%), metallic debris (7%), such as a cot and an empty butane cylinder (Fig. 5a), glass bottles (4%) (Fig. 5b) and clothes (2%) (Fig. 6). In dives 4 and 5, 33% and 100% of marine litter items were found within pockmarks (Figs. 5c, 5d and 7c). Marine litter average densities ranged between 0.001±0.09 to 0.01±0.002 items m -2 , with maximum densities of 2 items m -2 occurring within pockmarks. Trawl marks were observed in three of the six dives (Fig. 5e, 5f), with almost the totality of them concentrated in dive 3 (Table 3). A total of 93 trawl marks were observed, affecting 93 sampling units (4.88% of all sampling units). phalangium are marked in purple. Taxa with motile capacity have been marked in red.

Relationship between anthropogenic impacts and sessile megabenthic fauna

With the exception of a lost gear line, which occurred next to an I. elongata colony within dive 2 (Table 3), marine litter and megabenthic species did not co-occur. Only 9 out of the 93 sampling units containing trawl-marks were colonized by megabenthic species (Table 3), mainly represented by A. oligopodus, C. membranaceus and, to a lesser extent, by M. intestinalis, L. phalangium and H. coronata (Figs. 7a ,8).

Overall, megabenthic densities in dives where trawl-marks were present (0.5±0.2 ind.

m -2 mean±SD) were significantly lower (Adonis, PSEUDO-F = 26.9, p<0.001) than those where trawl-marks were absent (1.5 ± 0.7 ind. m -2 mean±SD).

Uprising non-retractile sessile species were exclusively found on untrawled sediment (Figs. 7b,7c and 8). 3.6. Variations in habitat complexity and biodiversity in trawled vs un-trawled areas A total of 15730 lebensspuren items were observed, occurring on 67.5% of the sampling units. Holes were the most abundant category (90%) followed by mounds (8%), furrows (1.3%) and trail-marks (0.7%) (Fig. 9). Overall, lebensspuren densities in dives where trawled marks were absent (26±16 mean±SD items m -2 ) were significantly higher (Adonis, PSEUDO-F = 1778, p<0.001) than those where trawling was present (1.8±3.2 mean±SD items m -2 ). Such pattern was observed for all lebensspuren categories with the exception of trail-marks, for which no significant differences were found (Fig. 9). Error bars represent the standard deviation. A total 527 sampling units from dives were trawling was present and 622 sampling units were trawling was absent were used.

Species richness was higher on untrawled dives, where 26 megabenthic species were observed, than in trawled dives, where 22 species were found. A similar pattern was observed for species turnover, which resulted higher in untrawled dives than in trawled ones (Fig. 10). sampling units from dives were trawling was absent were used for this analysis.

Discussion

Sessile megabenthic assemblages

The three megabenthic assemblages identified in this study (Fig. 4) were sparsely populated and dominated by passive suspension feeders (Table 1), agreeing with previous observations on the Mediterranean bathyal mud environments [START_REF] Pérès | The Mediterranean benthos[END_REF][START_REF] Emig | Bathyal zones of the Mediterranean continental slope: an attempt[END_REF][START_REF] Mastrototaro | A facies of Kophobelemnon (Cnidaria, Octocorallia) from Santa Maria di Leuca coral province (Mediterranean Sea)[END_REF][START_REF] Mastrototaro | Isidella elongata ( Cnidaria : Alcyonacea ) facies in the western Mediterranean Sea: visual surveys and descriptions of its ecological role[END_REF]. This contrasts with the bathyal soft sediment assemblages in more productive oceanic basins, such as those found in New Zealand or California, which received high amounts of phytodetrital material and are dominated by dense aggregations of deposit feeders [START_REF] Smith | Epibenthic megafuan of a bathyal basin off southern Claifornia: patterns of abundnace, biomass and dispersion[END_REF][START_REF] De Leo | Submarine canyons: Hotspots of benthic biomass and productivity in the deep sea[END_REF].

The two monospecific assemblages observed in this study were respectively dominated by the sea-pens Funiculina quadrangularis and Kophobelemnon stelliferum (Figs. 3c, 3d and 4), both being common inhabitants of bathyal muds of the western Mediterranean Sea (Gili and Ros,1987;[START_REF] Fabri | Megafauna of vulnerable marine ecosystems in French mediterranean submarine canyons: Spatial distribution and anthropogenic impacts[END_REF]; De La Torriente , 2018), where they have already been reported to form monospecific assemblages [START_REF] Pérès | The Mediterranean benthos[END_REF][START_REF] Mastrototaro | A facies of Kophobelemnon (Cnidaria, Octocorallia) from Santa Maria di Leuca coral province (Mediterranean Sea)[END_REF][START_REF] Pierdomenico | Effects of trawling activity on the bamboo-coral Isidella elongata and the sea pen Funiculina quadrangularis along the Gioia Canyon (Western Mediterranean, southern Tyrrhenian Sea)[END_REF].

Although F. quadrangularis were described to form dense aggregations on Mediterranean bathyal muds [START_REF] Pérès | Nouveau manuel de bionomie benthique de la mer Méditerranée[END_REF], the low densities observed in this study resemble previous observations from shelf-edge and submarine canyon environments of the western Mediterranean [START_REF] Fabri | Megafauna of vulnerable marine ecosystems in French mediterranean submarine canyons: Spatial distribution and anthropogenic impacts[END_REF][START_REF] Grinyó | Megabenthic assemblages in the continental shelf edge and upper slope of the Menorca Channel, Western Mediterranean Sea[END_REF][START_REF] Pierdomenico | Effects of trawling activity on the bamboo-coral Isidella elongata and the sea pen Funiculina quadrangularis along the Gioia Canyon (Western Mediterranean, southern Tyrrhenian Sea)[END_REF]. Conversely, K. stelliferum assemblages presented high densities than those reported by [START_REF] Mastrototaro | A facies of Kophobelemnon (Cnidaria, Octocorallia) from Santa Maria di Leuca coral province (Mediterranean Sea)[END_REF] in Santa Maria di Leuca (Ionian Sea -Central Mediterranean). De Clippele et al. ( 2015) observed that both species increase diversity at a local scale. Certainly, 22% of K. stelliferum colonies, found in the present study, were associated with decapods and macrourid fishes, reinforcing the general consensus that this species may provide shelter and act as a feeding grounds for associated species [START_REF] De Clippele | Fauna associated with cold water gorgonians and sea pens[END_REF]. Conversely, F. quadrangularis colonies were not associated to any other megabenthic species.

However, this observation might have been affected by the low number of colonies reported on this study.

The multispecific assemblage was widely represented, occurring in 99% of the occupied sampling units (Fig. 4). In this assemblage, the bamboo coral Isidella elongata (Fig. 3b) was the most abundant species (Table 1), forming meadows that extended over wide areas (Fig. 7b), which punctually reach densities up to 7 colonies m -2 . These density values are substantially higher than those recorded in other regions of the Mediterranean Sea [START_REF] Mastrototaro | Isidella elongata ( Cnidaria : Alcyonacea ) facies in the western Mediterranean Sea: visual surveys and descriptions of its ecological role[END_REF][START_REF] Pierdomenico | Effects of trawling activity on the bamboo-coral Isidella elongata and the sea pen Funiculina quadrangularis along the Gioia Canyon (Western Mediterranean, southern Tyrrhenian Sea)[END_REF][START_REF] Ingrassia | Isidella elongata (Cnidaria: Alcyonacea): First report in the Ventotene Basin (Pontine Islands, western Mediterranean Sea)[END_REF], where I. elongata reached maximum densities of 2.5 colonies m -2 [START_REF] Bo | Persistence of Pristine Deep-Sea Coral Gardens in the Mediterranean Sea (SW Sardinia)[END_REF]. I. elongata populations appeared to be in good conservation status, as no dead colonies where observed and partial necrosis was present in less than 6% of the observed colonies. This low necrosis ratio contrasted with what has been observed in impacted I. elongata populations located on trawling grounds of the western Mediterranean [START_REF] Pierdomenico | Effects of trawling activity on the bamboo-coral Isidella elongata and the sea pen Funiculina quadrangularis along the Gioia Canyon (Western Mediterranean, southern Tyrrhenian Sea)[END_REF]. I. elongata has a major ecological role in bathyal environments of the Mediterranean Sea, providing essential habitat for several ichthyic and decapod species [START_REF] Cartes | Geomorphological, trophic and human influences on the bamboo coral Isidella elongata assemblages in the deep Mediterranean: To what extent does Isidella form habitat for fish and invertebrates? Deep[END_REF][START_REF] Mastrototaro | Isidella elongata ( Cnidaria : Alcyonacea ) facies in the western Mediterranean Sea: visual surveys and descriptions of its ecological role[END_REF], representing a secondary biological hard substratum, elevated from the surrounding sediments [START_REF] Mastrototaro | Isidella elongata ( Cnidaria : Alcyonacea ) facies in the western Mediterranean Sea: visual surveys and descriptions of its ecological role[END_REF]. On this regard, 47% of I. elongata colonies where epiphyted by the crinoid Leptometra phalangium (Fig. 3b), and to a lesser extent, by the decapod Anamathia rissoana. More than 90% of L. phalangium individuals occurred on top of I. elongata colonies, generally hosting 1 crinoid

(1.7±1.0 ind./colony mean±SD), although largest colonies (>20 cm height) could host up to 5 crinoids. Since L. phalangium is a suspension feeder, it is likely that these crinoids are using I. elongata colonies as a physical support allowing to be detached from the seafloor and gaining exposure to more intense and food-rich currents, favoring their feeding rates. A similar functional relationship has been observed in the bathyal muds of the Balearic archipelago between I. elongata and the crinoid Antedon mediterraneum [START_REF] Mastrototaro | Isidella elongata ( Cnidaria : Alcyonacea ) facies in the western Mediterranean Sea: visual surveys and descriptions of its ecological role[END_REF].

Among the other uprising sessile fauna that integrated the multispecific assemblage, we encountered the Demosponge Thenea muricata and the Cerianthids Arachnanthus oligopodus and Cerianthus membranaceus (Figs. 3a, e andf). Thenea muricata has been described as a typical inhabitant of Mediterranean bathyal muds [START_REF] Vacelet | Eponges de la Roche du Large et de l'étage bathyal de Méditerranée (Récoltes de la soucoupe plongeante Cousteau et dragages)[END_REF]Maldonado et al., 2015). In the study area, this species presented a sparse distribution and occurred in low densities, in accordance with other studies from the western Mediterranean [START_REF] Santín | Sponge assemblages on the deep Mediterranean continental shelf and slope (Menorca Channel, Western Mediterranean Sea)[END_REF]. Conversely, cerianthids were amongst the most abundant species (38% of all sessile fauna), contrasting with previous observations depicting them as a rare group in Mediterranean bathyal muds [START_REF] Cartes | The distribution of megabenthic, invertebrate epifauna in the Balearic Basin (western Mediterranean) between 400 and 2300 m: Environmental gradients influencing assemblages composition and biomass trends[END_REF][START_REF] Mastrototaro | A facies of Kophobelemnon (Cnidaria, Octocorallia) from Santa Maria di Leuca coral province (Mediterranean Sea)[END_REF]. Up to date, information regarding megabenthic assemblages in deep sedimentary seafloor, mostly derives from experimental bottom trawls or benthic sledges (e.g. [START_REF] Gili | Types of bottoms and benthic cnidaria from the trawling grounds (Littoral and Bathyal off Catalonia (NE Spain))[END_REF][START_REF] Pansini | Sponges from trawl-exploitable bottoms of Ligurian and Tyrrhenian seas: distribution and ecology[END_REF][START_REF] Maynou | Effects of trawling on fish and invertebrates from deep-sea coral facies of Isidella elongata in the western Mediterranean[END_REF][START_REF] Mastrototaro | A facies of Kophobelemnon (Cnidaria, Octocorallia) from Santa Maria di Leuca coral province (Mediterranean Sea)[END_REF]. Although these gears have provided a great amount of occurrence data, they cannot be considered trustworthy from a quantitative point of view, often providing weak information about the abundance and distribution of sessile species [START_REF] Chimienti | ROV vs trawling approaches in the study of benthic communities: the case of Pennatula rubra (Cnidaria: Pennatulacea)[END_REF]. This lack of reliability is magnified for those species that have soft bodies and burrowing or withdrawing behaviors [START_REF] Durden | Abyssal hills -hidden source of increased habitat heterogeneity, benthic megafaunal biomass and diversity in the deep sea[END_REF][START_REF] Chimienti | ROV vs trawling approaches in the study of benthic communities: the case of Pennatula rubra (Cnidaria: Pennatulacea)[END_REF]. Therefore, since cerianthids rapidly and fully retract into sediments, it is likely that the abundance of this groups in Mediterranean bathyal muds has been widely underestimated.

The asteroid Hymenodiscus coronata and the holothurian Mesothuria intestinalis (Figs. 3g andh), typical inhabitants of Mediterranean abyssal muds [START_REF] Mecho | Visual faunistic exploration of geomorphological human-impacted deep-sea areas of the north-western Mediterranean Sea[END_REF], occurred as isolated individuals, being the most sparsely distributed component of the multispecific assemblage (Figs. 7a andb). In open slope environments, both species have generally presented low abundances [START_REF] Mecho | Visual faunistic exploration of geomorphological human-impacted deep-sea areas of the north-western Mediterranean Sea[END_REF], although M. intestinalis has been observed to form massive aggregations coinciding with increments of labile organic matter [START_REF] Cartes | The distribution of megabenthic, invertebrate epifauna in the Balearic Basin (western Mediterranean) between 400 and 2300 m: Environmental gradients influencing assemblages composition and biomass trends[END_REF].

The multispecific assemblage occurred on untrawled sediments (95% sampling units), trawled sediments (3.5% sampling units) and on pockmark fields (0.5% sampling units) (Figs. 4,7b and 7c). Although active pockmarks can potentially influence species distribution and abundance due to the influence of fluid seepage on water chemistry [START_REF] Zeppilli | Pockmarks enhance deep-sea benthic biodiversity: A case study in the western Mediterranean Sea[END_REF], in the study area no chemical nor physical changes were observed through the water column (gas seepage) or surrounding sediments (carbonate crusts) in correspondence to these features. This suggests that inactive pockmarks in this area do not exert any direct influence on megabenthic fauna distribution.

No environmental parameters are able to explain the segregation among assemblages, which could be identified from the video analyses. However, according to Peres and Picard (1964), this segregation may derive from substrate fluidity. While, F. quadrangularis and K. stelliferum are associated to viscous muds I. elongata is associated to compact muds (Peres and Picard, 1964). Therefore, further studies are warranted to assess potential differences in the physical, geological and geochemical characteristics of the sediments (e.g. grain-size, porosity, water content, composition, and organic content) to further understand which natural processes contribute to drive the distribution of these assemblages.

Marine litter

Litter observations in this study resemble what has already been observed in other deep Mediterranean environments, where plastic represents the most abundant component (Cau et al., 2019b;Pierdomenico et al., 2019a;[START_REF] Gerigny | Sea floor litter from the continental shelf and canyons in French Mediterranean Water: Distribution, typologies and trends[END_REF]. Most marine litter items occurred in low densities, despite higher concentrations within pockmarks, which hosted plastic bags and fishing gears (Figs. 5c andf). In line with previous observations, pockmarks may act as a sink [START_REF] Taviani | The Gela Basin pockmark field in the strait of Sicily (Mediterranean Sea): Chemosymbiotic faunal and carbonate signatures of postglacial to modern cold seepage[END_REF][START_REF] Mecho | Visual faunistic exploration of geomorphological human-impacted deep-sea areas of the north-western Mediterranean Sea[END_REF], constraining bottom-currents around them and inducing the accumulation of lighter litter, such as plastic bags or certain fishing-related debris (i.e. long-line fragments). Although the mechanisms behind the accumulation of large and heavier debris, such as steel reinforced rope (Fig. 5c), remain largely unknown, it is reasonable to hypothesize that heavy items mostly derive from ships' discard. A maritime-based origin for heavy litter in open-slope environments has been suggested

for other areas of the Mediterranean and North-Atlantic Ocean [START_REF] Ramírez-Llodra | Effects of natural and anthropogenic processes in the distribution of marine litter in the deep Mediterranena Sea[END_REF][START_REF] Pham | Marine litter distribution and density in European seas, from the shelves to deep basins[END_REF].

It is worth mentioning, that over 25% of global traffic of trading ships use the north Alboran Sea (around 60000 transits per year), making it the world's second busiest sea route (IUCN, 2007). For navigation safety reasons, the International Maritime Organization (IMO) stablished two mandatory routes named "traffic separation schemes" that divide the northern Alboran Sea. One of this traffic separation schemes, is coincident with the Carboneras and the North-South fault systems (Fig. 1). This could explain the contrasting situation observed between dives performed in the northern Alboran Sea and the Al Idrissi dive were no marine litter items where observed (Table . 3). However, this pattern should be carefully considered based on the small sampling effort made on the south Alboran Sea.

Finally, no interactions between marine litter and motile or sessile fauna were observed in the ROV dives, in contrast with what has been observed in regions with higher litter densities (Pierdomenico et al., 2019a;2019b).

The impact of bottom trawling

Despite the low sampling effort of our study (six ROV dives covering 5521 m) our results clearly show that bottom trawling affected sessile megabenthic species distribution and abundance, and caused a reduction in habitat complexity and beta diversity (Figs. 9 and 10). I. elongata, T. muricata, F. quadrangularis and K.

stelliferum were restricted to untrawled sampling units (Fig. 8). These species are extremely sensitive to bottom trawling [START_REF] Massutí | Demersal resource assemblages in the trawl fishing grounds off the Balearic Islands (western Mediterranean)[END_REF][START_REF] Mastrototaro | A facies of Kophobelemnon (Cnidaria, Octocorallia) from Santa Maria di Leuca coral province (Mediterranean Sea)[END_REF][START_REF] Pierdomenico | Effects of trawling activity on the bamboo-coral Isidella elongata and the sea pen Funiculina quadrangularis along the Gioia Canyon (Western Mediterranean, southern Tyrrhenian Sea)[END_REF]) and used to be common components of the Mediterranean trawling by-catch [START_REF] Relini | Osservazioni sulle comunità dei fondi strascicabili del Mar Ligure Centro-Orientale. Boll. degli Ist[END_REF][START_REF] Gili | Types of bottoms and benthic cnidaria from the trawling grounds (Littoral and Bathyal off Catalonia (NE Spain))[END_REF][START_REF] Pansini | Sponges from trawl-exploitable bottoms of Ligurian and Tyrrhenian seas: distribution and ecology[END_REF]. In fact, in ROV dives where trawl marks were present they presented significantly lower densities (0.5±0.1 ind. m -2 mean±SD; Adonis, PSEUDO-F=15.28; p<0.0001) than those where trawl marks were absent (0.87±0.73 ind. m -2 mean±SD).

These species populations have been widely decimated in the last decades, and are now mostly restricted to areas inaccessible to bottom trawling [START_REF] Mastrototaro | A facies of Kophobelemnon (Cnidaria, Octocorallia) from Santa Maria di Leuca coral province (Mediterranean Sea)[END_REF]2017;[START_REF] Bo | Persistence of Pristine Deep-Sea Coral Gardens in the Mediterranean Sea (SW Sardinia)[END_REF][START_REF] Santín | Sponge assemblages on the deep Mediterranean continental shelf and slope (Menorca Channel, Western Mediterranean Sea)[END_REF].

In trawled sampling units, occupancy was rather low and was restricted to cerianthids and echinoderms (Fig. 8). Cerianthids might be able to withstand bottom trawling through their ability to rapidly retract within tubes that are rooted tens of centimeters below the sediment surface [START_REF] Picton | Arachnanthus sarsi Carlgen, 1912: a redescription of a cerianthid anemone new to the British Isles[END_REF]. Echinoderms in deep Mediterranean environments are extremely susceptible to the destructive effects of bottom trawling, being unable to escape or withstand them [START_REF] Smith | Impact of otter trawling on an eastern Mediterranean commercial trawl fishing ground[END_REF][START_REF] Cartes | The distribution of megabenthic, invertebrate epifauna in the Balearic Basin (western Mediterranean) between 400 and 2300 m: Environmental gradients influencing assemblages composition and biomass trends[END_REF]. Thus, the presence of H. coronata in trawled sampling units (Fig. 8) might be explained by its motile capacity, which may allow re-occupancy of sampling units after the passage of trawl gears. However, several H. coronata individuals displayed a peculiar behavior in trawled sampling units. Individuals were observed on the edge of trawl marks extending their arms into the water column (Fig. 5f). In this slightly uplifted position, suspension feeders may be able to reach water layers exposed to more intense hydrodynamics, improving their feeding rates [START_REF] Carlier | Trophic relationships in a deep mediterranean cold-water coral bank (Santa Maria di Leuca, Ionian sea)[END_REF].

Lebensspuren density and megabenthic diversity were higher in untrawled dives than in trawled ones (Figs. 9 and 10), resembling similar patterns observed in other bathyal Mediterranean environments [START_REF] Mastrototaro | Isidella elongata ( Cnidaria : Alcyonacea ) facies in the western Mediterranean Sea: visual surveys and descriptions of its ecological role[END_REF]. As nets, trawl-doors and chains are dragged on the seafloor, sedimentary structures are flattened and bioturbator and habitat-forming species are removed or damaged [START_REF] Auster | The impacts of mobile fishing gear on seafloor habitats in the gulf of Maine (Northwest Atlantic): Implications for conservation of fish populations[END_REF][START_REF] Olsgard | Effects of bottom trawling on ecosystem functioning[END_REF][START_REF] Pierdomenico | Effects of trawling activity on the bamboo-coral Isidella elongata and the sea pen Funiculina quadrangularis along the Gioia Canyon (Western Mediterranean, southern Tyrrhenian Sea)[END_REF], resulting in a reduction of habitat complexity and, therefore, local biodiversity [START_REF] Probert | Benthic invertebrate bycatch from a deep-water trawl fishery, Chatham Rise, New Zealand[END_REF]. Indeed, bottom trawling can greatly alter benthic ecosystem functioning and productivity [START_REF] Jennings | Trawling disturbance can modify benthic production processes[END_REF], potentially having crucial long-term consequences for local fisheries [START_REF] Victorero | Species replacement dominates megabenthos beta diversity in a remote seamount setting[END_REF]. Considering the low recuperation rates of most species characterizing the observed assemblages [START_REF] Maynou | Effects of trawling on fish and invertebrates from deep-sea coral facies of Isidella elongata in the western Mediterranean[END_REF], our study's findings arise grave concern on the conservation status of these vulnerable benthic assemblages in the deep muddy bottoms of the Alboran Sea.

Conclusions

-Three megabenthic assemblages dominated by Funiculina quadrangularis, Kophobelemnon stelliferum and Isidella elongata respectively, were found in bathyal sedimentary environments of the Alboran Sea, within a depth range of 500-860 m.

-I. elongata and K. stelliferum were associated to motile taxa suggesting that these species may provide shelter and feeding grounds for associated species.

-Marine litter occurred in low densities. Plastic and fishing gears were the most abundant component of marine litter. Local circulation of bottom currents may force the accumulation of marine litter within pockmark depressions.

-Our results yield clear evidences that bottom trawling decreased the abundance of habitat forming species and lebensspuren items, reducing habitat complexity and negatively affecting biodiversity, however more extensive studies would be advisable to confirm this trend.

Fig. 1 .

 1 Fig. 1. Topographic and bathymetric map of the Alboran Sea, white rectangles indicate the location of dives, whose location correspond to different fault systems: North-South fault system (N-S), Carboneras fault system and Al-Idrissi Fault System. WAB: West Alboran Basin, EAB: East Alboran basin, SAB: South Alboran Basin. Yellow and red lines indicate the simplified patterns of the Atlantic Water (AW) gyres and the Mediterranean Levantine Intermediate Waters (LIW), respectively. Upper left inset: Western Mediterranean region indicate the Alboran Sea (AS).

Fig. 2 .

 2 Fig. 2. Lebensspuren categories: a) furrow with a Batynectes maravigna crab inside, b) mound, c) hole aggregations, and d) trail-mark generated by Mesothuria intestinalis. Scale bar: 20 cm.

Fig. 3 .

 3 Fig. 3. Most common sessile and low motile megabenthic species occurring in the Alboran sedimentary bottom. a) Thenea muricata, b) Isidella elongata and Leptometra phalangium (Lp), c)

Fig. 4 .

 4 Fig. 4. Non-metric multi-dimensional scaling (nMDS) ordination plot, data were square root

Fig. 5 .

 5 Fig. 5. Evidences of anthropogenic impact on the deep-sea sedimentary floor of the Alboran Sea: a) butane cylinder, b) glass bottle, debris accumulation inside pockmarks, c) reinforced rope, metal plates and plastic debris, d) lost net and light plastic debris, e) trawl-mark with macrourid fish, f) old trawl-mark with Hymenodiscus coronata. Scale bar: 20 cm. white

Fig. 7 .

 7 Fig. 7. Density plots showing variation of the abundance of different species and

Fig. 8 .

 8 Fig.8. Percentage of occurrence of sessile and low motile species in untrawled (grey) and trawled (green) sampling units. untrawled sampling units: 320, trawled sampling units: 9.

Fig. 9 .

 9 Fig. 9. Histograms comparing mean densities of different lebensspuren items in untrawled (grey) and trawled (green) dives. * Represents significant differences (p<0.001, Adonis).

Fig. 10 .

 10 Fig. 10. Randomized species accumulation curve calculated for trawled (green) and untrawled dives (grey). Colored areas around the curve represent the confidence intervals from standard deviation. A total of 290 sampling units from dives were trawling was present and 218

Table 1

 1 Location (geographic coordinates in WGS84), length, pockmark abundance and depth (minimum and maximum depth) of the SHAKE ROV dives. CFS: Carboneras fault system, NSFS: North-South fault system, AIFS: Al-Idrissi fault system, and Dv: Dive. The bamboo coral Isidella elongata, the cerianthid Arachnanthus oligopodus and the sponge Thenea muricata (Figs. 3a, 3b and 3f) were the most abundant species, representing 26.4%, 23.7% and 16.6% of all observed organisms, respectively. A. oligopodus was the most frequent species, occurring in 30.7% of the occupied sampling units, followed by both I. elongata and T. muricata, which both occurred in 21.6% of the occupied sampling units (Table2). Abundance and

	Zone Dv	Start	End		Length	Nº of	Depth
		Lat° N Lon° W Lat° N	Lon°	(m)	Pockmarks	range (m)
					W
	CFS	1 36.524	3.088	36.519	3.077	1700	0	704 -722
	NSFS 2 36.481	2.695	36.481	2.694	1109	0	639 -685
	NSFS 3 36.515	3.051	36.520	3.052	1368	1	638 -688
	CFS	4 36.532	2.619	36.541	2.618	168	0	836 -860
	CFS	5 35.498	3.737	35.504	3.739	725	8	821 -842
	AIFS	6 36.501	2.660	36.503	2.662	773	0	500 -526
	3.2. Megabenthic organisms: Occupancy and abundance
	A total of 447 organisms from 9 different species belonging to 5 different phyla were
	observed in the study area (Fig. 3 and Table 2), occurring in 17.3% of the 1904
	sampling units.

frequency progressively decreased from the asteroid Hymenodiscus coronata to the crinoid Leptometra phalangium and the holothurian Mesothuria intestinalis (Table

2

).

Table 2

 2 Total and relative abundance of sessile megabenthic species together with their occupancy (n° of sampling units occupied by a species) and frequency (% of occurrence in the whole set of occupied sampling units) in the study area. Average and maximum density of each sessile species within the occupied sampling units (n=329) are also shown. ind:

	individuals.
	Class	Species	Abundance	Occupancy	Average	Max density
							density ± SD
			Number	(%)	Number	(%)	(ind. m -2 )	(ind. m -2 )
	Desmospongia Thenea muricata	74	16.6	71	21.6	1.04±0.2	2
	Anthozoa	Isidella elongata	118	26.4	71	21.6	1.5±0.9	7
		Arachnanthus	106	23.7	101	30.7	1.03±0.2	2
		oligopodus
		Kophobelemnon	21	4.7	20	6.1	1.04±0.2	2
		stelliferum
		Cerianthus	17	3.8	17	5.2	1	1
		membranaceus
		Funiculina	7	1.6	7	2.1	1	1
		quadrangularis
	Crinoidea	Leptometra	35	7.8	26	7.9	1.2±0.6	3
		phalangium
	Astroidea	Hymenodiscus	36	8	36	10.9	1	1
		coronata
	Holothuria	Mesothuria	33	7.4	33	10	1	1
		intestinalis

Table 3

 3

	344
	345	dive, Av. Density: Average density.
	346
	347
				Marine litter			Trawl marks
	Zone	Dv Abundance	Occupancy	Av. density	SO	Abundance	Occupancy	Av. density	SO
			(Nº)	(Nº)	(Mean±SD)	(Nº)	(Nº)	(Nº)	(Mean±SD)	(Nº)
	CFS	1	15	1	0.01±0.002	0	6	6	0.002±0.04
	NSFS	2	7	4	0.060±0.200	1	0	0	0
	NSFS	3	14	16	0.015±0.102	0	84	84	0.081±0.215
	CFS	4	1	2	0.001±0.092	0	3	3	0.004±0.043

Abundance and frequency of the occurrence of marine litter and trawl-marks in the 341 study area. Sampling units with organisms (SO): number of sampling units simultaneously 342 occupied by sessile megabenthic species and marine litter items or trawl-marks. CFS: 343 Carboneras fault system, NSFS: North South fault system, AIFS: Al-Idrissi fault system; Dv:

Acknowledgements

The data for this study were collected during the Spanish national project SHAKE (CGL2011-3005-C02-02). We acknowledge the EU Eurofleets-2 Project, which provided the ROV Max Rover from the Hellenic Centre for Marine Research (Greece) during the SHAKE cruise (IRIS project -Embarked Equipment 2013 Call EF2-EE-003. GA 312762), Finally, we gratefully acknowledge all the participants on the SHAKE cruise and the crew on board of the R/V "Sarmiento de Gamboa" and Professor Pablo J. Lopez from the University of Seville for his help to identify several megabenthic species.


Jeanne Pierron

Elina El Dirani

Stéphane Sanchez

Wissam El-Hage

Coraline Hingray
email: c.hingray@chru-nancy.fr

Representation of Female speakers at French psychiatry conferences

Keywords: Femme, Psychiatre, Congrès, Parité Female speaker, Conference, Psychiatry, Parity

Objectifs. -Décrire l'évolution de la représentation des femmes aux congrès de psychiatrie en France et la comparer à l'évolution de la représentation des femmes parmi les psychiatres français. Méthodes. -Les données ont été obtenues par les programmes des congrès de l'Encéphale et du Congrès Français de Psychiatrie de 2009 à 2018 ainsi qu'auprès du Conseil National de l'Ordre des Médecins. La proportion moyenne de femmes aux deux congrès par année a été obtenue en pondérant la moyenne par les différents effectifs des intervenants aux deux congrès. Résultats. -La différence de proportion de femmes entre les psychiatres français et les intervenants aux congrès varie entre 21 % en 2009 et 17 % en 2016, avec une proportion de femmes psychiatres en activité en augmentation (de 46 % à 51 %) et supérieure pour chaque année à celle des femmes intervenant aux congrès (de 25 à 32 %). La proportion de femmes intervenant sur des thèmes de pédopsychiatrie (41-59 %) est supérieure à celles intervenant sur des thèmes de psychiatrie générale (24-33 %) et d'addictologie (10-39 %). La proportion de femmes est faible dans les symposiums des compagnies pharmaceutiques (7-24 %), les membres des comités d'organisation et scientifiques (13-33 %) et les présidents de séances (19-28 %), bien qu'elle augmente avec le temps. Perspectives. -Cette sous-représentation des femmes dans les congrès de psychiatrie en France pourrait possiblement être améliorée par l'inscription de la question de la parité à la politique des congrès de psychiatrie, parmi les intervenants comme parmi les comités scientifiques et d'organisation.

Introduction

Depuis la première femme médecin française, Madeleine Brès, en 1875 [START_REF]La première doctoresse française : conversation avec Mme Madeleine Brès, docteur en médecine[END_REF], la profession médicale s'est largement féminisée avec les années. En 2018, on compte 43 % de femmes parmi les médecins inscrits à l'Ordre des Médecins en France [START_REF]L'atlas de la démographie médicale[END_REF]. Pour autant, le nombre de femmes diminue significativement quand on avance dans la hiérarchie hospitalouniversitaire. On parle ainsi de « plafond de verre », terme utilisé depuis la fin des années 1970 aux États-Unis, pour définir « les barrières invisibles, artificielles, créées par des préjugés comportementaux et organisationnels, qui empêchent les femmes d'accéder aux plus hautes responsabilités » [START_REF] Latour | Le plafond de verre universitaire : pour en finir avec l'illusion méritocratique et l'autocensure[END_REF].

En France, en 2018, dans l'enseignement supérieur, toutes filières confondues, les femmes représentent 25 % des professeurs des universités et 35 % des maîtres de conférence des universités. Dans la filière hospitalo-universitaire pour l'année universitaire 2017-2018, les femmes représentent 28 % des enseignants titulaires en activité, contre 39 % dans la filière universitaire globale française [START_REF]l'innovation. Vers l'égalité femmes-hommes ? Chiffres clés[END_REF]. À titre d'exemple, au sein du groupement hospitalier de la Pitié Salpêtrière à Paris en 2017, on retrouve une représentation paritaire hommes/femmes (49 % de femmes) parmi les effectifs médicaux totaux, mais seulement 15 % de femmes parmi les professeurs des universités/praticiens hospitaliers (PU-PH) [START_REF] Rosso | Plafond de verre pour les femmes dans les carrières hospitalo-universitaires en France[END_REF].

Plusieurs études ont également été réalisées dans le monde ces dernières années pour connaître la situation de la parité hommes femmes au sein des congrès scientifiques. Les femmes sont presque systématiquement sous-représentées, que ce soit par exemple dans des congrès scientifiques non médicaux tels que les congrès de géophysique [START_REF] Ford | Gender inequity in speaking opportunities at the American Geophysical Union Fall Meeting[END_REF], des congrès médicaux aux États-Unis et au Canada [START_REF] Ruzycki | Trends in the Proportion of Female Speakers at Medical Conferences in the United States and in Canada, 2007 to 2017[END_REF], des congrès internationaux de médecine d'urgence [START_REF] Carley | Are there too few women presenting at emergency medicine conferences?[END_REF], ou des congrès médicaux en Australie [START_REF] Modra | Female representation at Australasian specialty conferences[END_REF]. Toutefois, la parité émerge dans certaines conférences comme les conférences américaines de virologie [START_REF] Kalejta | Gender Parity Trends for Invited Speakers at Four Prominent Virology Conference Series[END_REF] et les congrès américains de dermatologie [START_REF] Mujahid | Trends in Gender of Speakers at the American Academy of Dermatology Annual Meeting, 2010-2018[END_REF]. Certains congrès exigent la parité dans la constitution du programme scientifique, comme par exemple l'European Conference on brain stimulation in psychiatry [START_REF] Brem | There is no magic in speaker policies: creating gender equality at brain stimulation conferences : Editorial II to the supplement from the 2nd European Conference on brain stimulation in psychiatry[END_REF].

Les congrès nationaux scientifiques font intervenir les professionnels actifs, experts, reconnus dans leur discipline, et font la promotion des scientifiques actifs dans la recherche. Ils sont également un moyen de diffusion, de reconnaissance de son travail et de partage avec ses pairs. Il est donc légitime de penser que la participation en tant qu'intervenant à un congrès scientifique national a une certaine importance dans une carrière professionnelle.

Mais qu'en est-il au sein de la spécialité de psychiatrie en France depuis la première femme psychiatre, Constance Pascal, en 1908 [START_REF] Barbier | Constance Pascal: pioneer of French psychiatry[END_REF] ? Comme les autres professions médicales, la profession de psychiatre s'est largement féminisée, atteignant la parité hommes femmes, avec 51 % de femmes en 2018 parmi les psychiatres inscrits à l'Ordre des Médecins en France. Dans ce travail, nous avons considéré la participation aux congrès nationaux de psychiatrie comme un reflet intéressant d'une forme de reconnaissance professionnelle complémentaire et différente du statut d'exercice.

Notre objectif principal était de décrire l'évolution de la représentation des femmes parmi les intervenants aux deux principaux congrès nationaux français de psychiatrie, à savoir, l'Encéphale et le Congrès Français de Psychiatrie (CFP), de 2009 à 2018, et de la comparer à l'évolution de la représentation des femmes parmi les psychiatres français. Notre objectif secondaire était de décrire cette évolution parmi les thématiques de psychiatrie générale, de pédopsychiatrie et d'addictologie aux congrès et de la comparer à l'évolution de la représentation des femmes parmi les psychiatres d'adulte, pédopsychiatres et addictologues en France. Nous décrirons également l'évolution de la représentation des femmes parmi les présidences de séances, les comités d'organisation et scientifiques, et les symposiums de compagnies pharmaceutiques aux congrès.

Méthodes Échantillon d'étude

Variables

Il existe des différences de format et de présentation dans les deux congrès. Pour l'Encéphale, nous avons recueilli l'information sur le sexe des intervenants des séances plénières, regards croisés, rencontres avec l'expert, communications orales, focus, connaissances approfondies, sessions « jeunes psychiatres » et symposia satellites des laboratoires. Les « petits-déjeuners débats » organisés par les laboratoires ont été inclus parmi les symposiums de compagnies pharmaceutiques. Nous avons exclu les sessions infirmières ainsi que les présentations de posters. Pour le CFP, nous avons recueilli l'information sur le sexe des intervenants des forums des associations, des conférences plénières, des sessions thématiques, des rencontres avec l'expert, des débats ainsi que des symposia satellites des laboratoires. Les communications orales et affichées n'étaient pas détaillées dans les programmes et n'ont donc pas été incluses.

Le sexe des intervenants était défini à l'aide du prénom ou à l'aide d'une recherche sur internet quand le prénom ne suffisait pas à définir le sexe ou que le prénom n'était pas connu.

Des données démographiques ont été collectées auprès du Conseil National de l'Ordre des Médecins : le nombre d'hommes et femmes psychiatres en activité en France de 2007 à 2018, le nombre d'hommes et femmes psychiatres selon leur statut hospitalo-universitaire (assistant des hôpitaux, chef de clinique assistant des hôpitaux (CCA), maître de conférence des universités/praticien hospitalier (MCU-PH), praticien hospitalier (PH), professeur des universités/praticien hospitalier (PU-PH)) de 2010 à 2018 ainsi que le nombre d'hommes et femmes psychiatres en activité ayant validé une compétence spécifique en addictologie et pédopsychiatrie, de 2010 à 2018.

Nous avons également cherché à recueillir le nombre de chefs de pôle et chefs de service des services de psychiatrie en France selon le sexe mais ces données n'existaient ni auprès du Centre National de Gestion (CNG), ni auprès du Conseil National de l'Ordre des Médecins, ni auprès du Ministère des Solidarités et de la Santé, ni auprès de la Direction de la Recherche, des Études, de l'Évaluation et des Statistiques (DREES).

Analyses statistiques

Les variables descriptives quantitatives ont été décrites à l'aide de la moyenne et de l'écart type. Les variables qualitatives par la fréquence et le pourcentage. La proportion moyenne de femmes aux deux congrès par année a été obtenue en pondérant la moyenne par les différents effectifs des intervenants aux deux congrès. La proportion de femmes parmi les psychiatres d'adultes est une estimation qui a été obtenue en soustrayant le nombre de femmes et d'hommes pédopsychiatres au nombre de femmes et d'hommes psychiatres. Un test de Chi 2 de tendance a été utilisé pour comparer l'évolution de l'écart de proportion au cours du temps. Des modèles de régressions linéaires simples ont testé la significativité de l'évolution de la population dans le temps. Pour l'ensemble des analyses le logiciel SPSS 21 (Chicago, Inc) a été utilisé et un seuil de significativité de 0,05 a été choisi pour l'ensemble des analyses.

Résultats Données globales

Nous décrivons ici la représentation des femmes intervenant aux congrès de psychiatrie en France et parmi les psychiatres inscrits à l'Ordre des Médecins. Les intervenants aux congrès sont les personnes qui interviennent en tant que président, modérateur ou orateur dans les différentes conférences. De 2009 à 2018, aux congrès de l'Encéphale et du CFP, nous avons identifié 5 537 interventions.

-Insérer ici Tableau 1 -Comme le montre le Tableau 1, la proportion de femmes intervenant aux congrès varie de 25 % en 2009 à 32 % en 2018. En parallèle, la proportion de femmes psychiatres inscrites à l'Ordre des Médecins en France progresse linéairement de 46 % en 2009 à 51 % en 2018, avec une proportion de femmes psychiatres supérieure à celle des hommes depuis 2016.

-Insérer ici Figure 1 -Pendant ces dix années, la différence de proportion de femmes parmi les psychiatres inscrits à l'Ordre des Médecins et parmi les intervenants aux congrès du CFP et de l'Encéphale varie entre 21 % en 2009 et 17 % en 2016, avec une proportion de femmes parmi les psychiatres inscrits à l'Ordre des médecins supérieure pour chaque année à celle parmi les intervenants aux congrès. Cet écart de croissance entre les femmes psychiatres et celles intervenant aux congrès diminue dans le temps, ce qui signifie que la proportion de femmes aux congrès tend à augmenter plus rapidement que la proportion de femmes psychiatres en activité en France, sans pour autant que ce soit significatif (p = 0,09) (Figure 1).

Données par thématique

Nous décrivons ici la représentation des femmes intervenant sur les thématiques de psychiatrie générale, addictologie et pédopsychiatrie aux congrès de psychiatrie en France et parmi les psychiatres d'adultes, pédopsychiatres, addictologues, inscrits à l'Ordre des Médecins.

-Insérer ici Figure 2 -Comme on peut le voir sur la Figure 2, entre 2009 et 2018, la proportion de femmes intervenant aux congrès varie entre 24 % et 33 % sur les thèmes de psychiatrie générale, entre 41 % et 59 % sur les thèmes de pédopsychiatrie et entre 10 % et 39 % sur les thèmes d'addictologie. La proportion de femmes intervenant sur les thèmes de pédopsychiatrie est supérieure à la proportion de femmes intervenant sur les deux autres thèmes.

-Insérer ici Tableau 2 -Le Tableau 2 montre que concernant les psychiatres d'adultes inscrits à l'Ordre des médecins, la proportion de femmes augmente progressivement de 46 % à 50 % de 2010 à 2018. Lorsque l'on compare ces proportions à celles des intervenantes aux congrès sur les thèmes de psychiatrie générale, on note un écart de proportion de 17 % en 2010 et 19 % en 2018 (avec un maximum de 24 % en 2014 et un minimum de 16 % en 2012). La proportion de femmes parmi les pédopsychiatres inscrits à l'Ordre des médecins augmente progressivement de 72 % à 75 % de 2010 à 2018. Lorsque l'on compare ces proportions à celles des intervenantes aux congrès en pédopsychiatrie, on note un écart de proportion de 25 % en 2010 et 22 % en 2018 (avec un maximum de 32 % en 2011 et un minimum de 15 % en 2016). Pour ce qui est des psychiatres addictologues inscrits à l'Ordre des médecins, la proportion de femmes varie de 50 % en 2010 à 53 % en 2018 avec un minimum de 49 % en 2014. Lorsque l'on compare ces proportions à celles des intervenantes aux congrès en addictologie, on note un écart de proportion de 40 % en 2010 et 19 % en 2018 (avec un minimum de 10 % en 2014). Ainsi, sans que ce soit significatif, l'écart de croissance diminue avec les années pour les thèmes de pédopsychiatrie et d'addictologie alors qu'il augmente pour le thème de psychiatrie générale.

Données par rôle

Nous décrivons ici la représentation des femmes intervenant comme présidentes de séances, membres des comités d'organisation et scientifiques, ou intervenant aux symposiums de compagnies pharmaceutiques aux congrès de psychiatrie en France.

-Insérer ici Figure 3 -De 2009 à 2018, nous observons une proportion de femmes faible parmi les intervenants aux symposiums des compagnies pharmaceutiques (7 % à 24 %) inférieure à celles parmi les membres des comités d'organisation et scientifiques (13 % à 33 %) et les présidents de séances (19 % à 28 %), elles-mêmes inférieures à celle parmi tous les intervenants confondus (25 % à 33 %) (Figure 3). Cependant, de 2009 à 2018, la proportion de femmes augmente avec le temps, quel que soit le rôle au congrès.

Discussion

De 2009 à 2018, les femmes intervenant aux congrès de psychiatrie de l'Encéphale et du CFP sont sous-représentées par rapport aux femmes psychiatres en France qui sont majoritaires depuis 2016, en ne dépassant pas 33 % des intervenants. Pour autant, la proportion de femmes aux congrès augmente significativement avec les années, et tend à augmenter plus rapidement que la féminisation de la profession.

Cette sous-représentation s'observe également au sein des différentes thématiques des conférences de psychiatrie générale, de pédopsychiatrie et d'addictologie par rapport à la proportion de femmes parmi, respectivement, les psychiatres d'adultes, les pédopsychiatres, et les addictologues inscrits à l'Ordre des Médecins. Sans que ce soit significatif, la croissance de la représentation des femmes au cours du temps aux congrès parmi les intervenants sur des thèmes de psychiatrie générale est moins marquée que celles des thèmes de pédopsychiatrie et d'addictologie. Cette sous-représentation est davantage marquée au sein des comités d'organisation et scientifiques ainsi qu'au sein des présidences de séances, et encore davantage au sein des symposiums de compagnies pharmaceutiques, avec une proportion de femmes bien inférieure aux tendances nationales.

À notre connaissance, aucun état des lieux n'avait encore été fait parmi les congrès de psychiatrie en France, bien que la sous-représentation des femmes aux congrès médicaux soit connue dans d'autres spécialités et dans d'autres pays [START_REF] Ruzycki | Trends in the Proportion of Female Speakers at Medical Conferences in the United States and in Canada, 2007 to 2017[END_REF][START_REF] Carley | Are there too few women presenting at emergency medicine conferences?[END_REF][START_REF] Modra | Female representation at Australasian specialty conferences[END_REF][START_REF] Klein | Speaking out about gender imbalance in invited speakers improves diversity[END_REF]. L'augmentation de la proportion des femmes aux congrès de psychiatrie et parmi les psychiatres en France au cours de la dernière décennie reflète l'augmentation de la proportion de femmes dans le milieu médical français [START_REF]drees -Etudes et statistiques -La démographie des médecins[END_REF]. Dans une étude réalisée parmi de nombreux congrès de diverses spécialités médicales aux USA et au Canada, la représentation des femmes parmi les intervenants aux congrès était presque équivalente à la représentation des femmes parmi les médecins spécialistes et généralistes en activité en 2007, et était même légèrement supérieure en 2015 [START_REF] Ruzycki | Trends in the Proportion of Female Speakers at Medical Conferences in the United States and in Canada, 2007 to 2017[END_REF], ce qui est très différent des résultats de notre étude. Il faut noter que la proportion de femmes médecins en activité aux USA est inférieure à celle en France, avec une proportion de femmes médecins de 35 % en 2017, et notamment dans la spécialité de psychiatrie de 39 % versus 51 % en France la même année [START_REF]Data and Reports -Workforce -Data and Analysis -Active Physicians by Sex and Specialty[END_REF]. On pourrait supposer que la disparité entre les hommes et les femmes aux USA ne se crée pas au même niveau qu'en France.

La disparité entre les hommes et les femmes peut s'observer à d'autres niveaux, parmi d'autres formes de reconnaissance de son travail : la publication d'articles scientifiques, le salaire, le statut hospitalo-universitaire. Notre étude n'a pas évalué ces facteurs, mais d'autres travaux les ont explorés. Autant, voire davantage que l'intervention aux congrès, la publication d'articles dans des revues renommées a une importance dans la carrière universitaire. On retrouve dans la littérature une sous-représentation des femmes parmi les auteurs des articles de revues de psychiatrie (The American Journal of Psychiatry ou The British Journal of Psychiatry) ou d'autres spécialités, en anglais, à facteur d'impact élevé, malgré une tendance à la hausse depuis les années 90 [START_REF] Amering | The Gender Gap in High-Impact Psychiatry Journals[END_REF][START_REF] Jagsi | The "Gender Gap" in Authorship of Academic Medical Literature -A 35-Year Perspective[END_REF]. On retrouve également une différence de salaire parmi les médecins américains selon leur sexe, et ce, même à ancienneté, position, publications, temps de travail égaux [START_REF] Jagsi | Gender Differences in the Salaries of Physician Researchers[END_REF]. Concernant les statuts hospitalo-universitaires, une autre étude encore montre, en 2014, que les hommes étaient beaucoup plus susceptibles que les femmes de devenir professeurs des universités aux États-Unis, à âge, ancienneté, productivité dans la recherche égaux [START_REF] Jena | Sex Differences in Academic Rank in US Medical Schools in 2014[END_REF]. Parmi les psychiatres américains, des années 50 aux années 80, une étude montre aussi que les hommes étaient plus susceptibles d'avoir des activités de recherche que les femmes [START_REF] Leibenluft | Sex Differences in Rank Attainment and Research Activities Among Academic Psychiatrists[END_REF]. Une étude plus récente montre qu'il en est de même actuellement [START_REF] Sheikh | Influences for Gender Disparity in Academic Psychiatry in the United States[END_REF]. Parmi les psychiatres français, les données de l'Ordre des Médecins de 2010 à 2018 montrent bien aussi ce plafond de verre au rang des professeurs des universités (Figure 4). Il y a en effet une nette surreprésentation féminine parmi les assistants des hôpitaux et les chefs de clinique qui contraste avec une très nette sous-représentation parmi les professeurs des universités. La proportion de femmes parmi les maîtres de conférence des universités est difficilement interprétable car elle représente de très faibles effectifs.

-Insérer ici Figure 4 -Les facteurs qui peuvent expliquer cette sous-représentation des femmes au sein des congrès sont multiples, variés et complexes. Une des hypothèses est d'ordre démographique, c'est-à-dire que l'augmentation de la proportion des femmes médecins serait trop récente pour que la parité apparaisse à tous les niveaux. Cette hypothèse n'est pas confirmée par les données de la littérature en ce qui concerne les statuts hospitalo-universitaires [START_REF] Rosso | Plafond de verre pour les femmes dans les carrières hospitalo-universitaires en France[END_REF] et en ce qui concerne les congrès, l'âge des intervenants n'a pas été étudié. Un autre facteur est l'importance accordée à la vie personnelle et familiale plutôt que professionnelle par les femmes médecins. Une étude montre en effet que les femmes médecins qui ont des enfants publient moins et ont moins de soutien institutionnel que les hommes qui ont des enfants ou les femmes qui n'en ont pas [START_REF] Carr | Relation of Family Responsibilities and Gender to the Productivity and Career Satisfaction of Medical Faculty[END_REF]. Une autre étude montre que le frein ressenti en lien avec la gestion des enfants par les femmes est plus important que pour les hommes [START_REF] Rosso | Plafond de verre pour les femmes dans les carrières hospitalo-universitaires en France[END_REF]. Une autre justification serait que les femmes reçoivent moins d'encouragement pour présenter leur travail de la part de mentors ou de superviseurs ou ont moins conscience de la valeur de présenter leur travail [START_REF] Sambunjak | Mentoring in Academic Medicine: A Systematic Review[END_REF]. Les stéréotypes de genre implicites rentrent aussi en compte. Par exemple, la gloire est plus facilement attribuée aux hommes qu'aux femmes [START_REF] Banaji | Implicit gender stereotyping in judgments of fame[END_REF]. Aussi, de manière inconsciente, les résumés des articles scientifiques faits par des auteurs masculins sont considérés comme de meilleure qualité que ceux réalisés par des auteurs féminins [START_REF] Knobloch-Westerwick | The Matilda Effect in Science Communication: An Experiment on Gender Bias in Publication Quality Perceptions and Collaboration Interest[END_REF]. Une autre hypothèse serait aussi que les approches des femmes contribuent à réduire leur visibilité et ainsi, peut-être à exacerber l'iniquité. Par exemple, les femmes refusent davantage les invitations à parler en congrès scientifiques que les hommes [START_REF] Knobloch-Westerwick | The Matilda Effect in Science Communication: An Experiment on Gender Bias in Publication Quality Perceptions and Collaboration Interest[END_REF][START_REF] Schroeder | Fewer invited talks by women in evolutionary biology symposia[END_REF]. Les femmes médecins seraient également moins compétitrices que les hommes [START_REF] Rosso | Plafond de verre pour les femmes dans les carrières hospitalo-universitaires en France[END_REF]. Aussi, une étude montre que les femmes universitaires priorisent l'enseignement plutôt que la recherche et sont donc moins présentes aux congrès [START_REF] Winslow | Gender Inequality and Time Allocations Among Academic Faculty[END_REF]. On retrouve également dans la littérature que les femmes citent moins leur propre travail dans les articles et que les hommes ont plus tendance à citer des hommes [START_REF] Maliniak | The Gender Citation Gap in International Relations[END_REF]. Une étude montre aussi que les femmes préfèrent les présentations de posters ou les présentations courtes et auraient tendance à refuser les longues présentations [START_REF] Jones | Gender differences in conference presentations: a consequence of self-selection?[END_REF]. Dans notre étude, nous n'avons pas étudié les présentations de posters au sein des congrès de l'Encéphale et du CFP mais on pourrait se demander si la proportion de femmes n'y est pas plus élevée. Il n'y a pas d'explication spécifique dans la littérature pour expliquer la sous-représentation des femmes aux symposiums des compagnies pharmaceutiques aux congrès dans notre étude. Les femmes sont-elles moins sollicitées par les laboratoires qui favorisent les hommes, à la recherche d'un affichage plus rassurant, plus paternaliste, ou bien les femmes sont-elles plus vigilantes aux conflits d'intérêts ? La sousreprésentation des femmes dans les comités d'organisation et scientifiques des congrès n'est pas non plus spécifiquement expliquée dans la littérature. On peut faire l'hypothèse de stéréotypes de genre implicites.

Notre étude comporte certaines limites. Une des limites pourrait être l'absence d'ajustement des données sur l'âge des intervenants, afin d'étayer l'hypothèse démographique qui expliquerait la faible proportion de femmes intervenant aux congrès par rapport aux femmes psychiatres, par une moyenne d'âge plus élevée des intervenants aux congrès que celle des psychiatres actifs en France, qui ne soit ainsi pas représentative de la répartition homme/femme actuelle des psychiatres français. Une deuxième limite est l'existence de biais de sélection à plusieurs niveaux : les intervenants aux congrès de psychiatrie ne sont pas exclusivement des psychiatres, mais aussi, plus rarement, des psychologues, des scientifiques non-médecins, des hommes de lettres, des juristes et ne sont donc pas parfaitement représentatifs de la population de psychiatres. En outre, une partie des intervenants n'est pas française et ne représente donc pas parfaitement la population de psychiatres français. Aussi, une même personne réalisant plusieurs interventions a pu être recueillie plusieurs fois. Un autre biais de sélection existe parmi les données de l'Ordre des Médecins, tous les médecins ayant validé une compétence spécifique de pédopsychiatrie ou d'addictologie n'ont pas signalé cette compétence à l'Ordre des Médecins. De plus, avoir validé la compétence ne signifie pas forcément exercer dans ce domaine de compétence. En outre, le nombre de psychiatres d'adultes n'est qu'une estimation. Enfin, nous n'avons pas obtenu de résultats significatifs, notamment parce que nous avions un recul temporel insuffisant de dix années.

Perspectives

La prise en compte de la sous-représentation des femmes aux principaux congrès de psychiatrie en France pourrait permettre d'agir en faveur d'une meilleure équité. Ce calcul de la proportion des femmes par année aux différents congrès pourrait être poursuivi régulièrement par les instances des congrès eux-mêmes. C'est de cette manière qu'en 2012, la revue Nature a analysé la parité de ses auteurs dans certaines de ses sections et en a augmenté la proportion de femmes [START_REF] Conley | À call to commission more women writers[END_REF]. L'inscription de la question de la parité à la politique des congrès permettrait également une vigilance vis-à-vis des modalités de sélection des intervenants aux congrès. Sensibiliser les membres des comités qui sélectionnent les orateurs à la question de la parité aux congrès permettrait aussi de la modifier [START_REF] Martin | Ten simple rules to achieve conference speaker gender balance[END_REF]. Une augmentation de la proportion de femmes parmi les comités scientifiques et/ou d'organisation qui choisissent les intervenants des congrès pourrait aussi permettre une augmentation de la proportion de femmes parmi les intervenants [START_REF] Casadevall | The Presence of Female Conveners Correlates with a Higher Proportion of Female Speakers at Scientific Symposia[END_REF][START_REF] Isbell | Stag Parties Linger: Continued Gender Bias in a Female-Rich Scientific Discipline[END_REF][START_REF] Sardelis | Not "Pulling up the Ladder": Women Who Organize Conference Symposia Provide Greater Opportunities for Women to Speak at Conservation Conferences[END_REF]. Une manière de réduire l'effet Matilda, qui est défini par une minimisation de la contribution des femmes scientifiques à la recherche, serait aussi d'être vigilant à l'équité pour ce qui est des orateurs invités [START_REF] Jones | Gender differences in conference presentations: a consequence of self-selection?[END_REF]. C'est d'ailleurs ce que recommande un rapport de 2006 du Comité pour l'égalité professionnelle entre les femmes et les hommes dans l'enseignement supérieur et la recherche qui stipule que « la cohérence entre la proportion de femmes et d'hommes dans le colloque (conférenciers invités, comités d'organisation, etc.) et dans le vivier de la discipline scientifique concernée doit être un critère dans l'attribution de subventions aux colloques scientifiques » [START_REF]Comité pour l'égalité professionnelle entre les femmes et les hommes dans l'enseignement supérieur et la recherche[END_REF]. Aussi, la connaissance de la tendance des femmes à être moins leaders, moins compétitives pourrait être prise en compte [START_REF] Jones | Gender differences in conference presentations: a consequence of self-selection?[END_REF]. Enfin, à long terme, une exposition plus importante des femmes aux congrès pourrait permettre de combattre les stéréotypes de genre [START_REF] Schroeder | Fewer invited talks by women in evolutionary biology symposia[END_REF][START_REF] Dasgupta | Seeing is believing: Exposure to counterstereotypic women leaders and its effect on the malleability of automatic gender stereotyping[END_REF].

Déclaration d'intérêts

Les auteurs déclarent ne pas avoir de conflits d'intérêts en relation avec cet article.

Références Légende des figures

Figure 1 .

 1 Figure 1. Proportion de femmes intervenant aux congrès et de femmes psychiatres inscrites à l'Ordre des médecins.

Figure 2 .

 2 Figure 2. Proportion de femmes intervenant aux congrès dans différentes thématiques.

Figure 3 .

 3 Figure 3. Proportion de femmes intervenant aux congrès à des rôles différents.

Figure 4 .

 4 Figure 4. Proportion de femmes parmi les psychiatres inscrits à l'Ordre des médecins en France selon le statut hospitalo-universitaire.

Figure 1 .Figure 2 .

 12 Figure 1. Proportion de femmes intervenant aux congrès et de femmes psychiatres inscrites à l'Ordre des médecins

Figure 3 .

 3 Figure 3. Proportion de femmes intervenant aux congrès à des rôles différents

Figure 4 .

 4 Figure 4. Proportion de femmes parmi les psychiatres inscrits à l'Ordre des Médecins en France selon le statut hospito-universitaire

Tableau 1. Proportion de femmes parmi les intervenants des congrès de l'Encéphale et du CFP, et parmi les psychiatres inscrits à l'Ordre des Médecins

	Année	Proportion de femmes intervenant aux congrès de l'Encéphale et du CFP	Proportion de femmes psychiatres inscrites à l'Ordre des médecins
	2009	25%	(110/445)	46%	(5533/12126)
	2010	27%	(131/478)	47%	(5868/12618)
	2011	26%	(138/524)	47%	(6109/12981)
	2012	29%	(139/473)	48%	(6330/13296)
	2013	28%	(141/506)	48%	(6541/13598)
	2014	28%	(164/588)	49%	(6746/13848)
	2015	32%	(194/599)	49%	(6963/14093)
	2016	33%	(217/665)	50%	(7180/14293)
	2017	33%	(197/603)	51%	(7341/14469)
	2018	32%	(211/656)	51%	(7527/14654)

Note : Proportion de femmes en % (nombre de femmes intervenantes/nombre total d'intervenants)