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The Habitats Directive (92/43/CEE) is one of the political pillars of the European Union in terms of marine biodiversity. Under the directive, each Member State must report periodically the conservation status and evolution trends of species and habitats of Community interest. This conservation status of habitats is characterised by four parameters: habitat range, habitat area, habitat structure and functions, and future prospects according to the pressures acting on the habitat and the management measures put in place. In previous reports, the assessment of the 1170-Reefs habitat considered only partially the geological and biogenic reefs of the deep sea (bathyal). To overcome such a knowledge gap, a scientific review was carried out according to the four evaluation parameters in order to advance an overall assessment of the bathyal Reefs for the French Atlantic and Mediterranean marine biogeographical regions. The overall assessment of the conservation status of bathyal Reefs is « unfavourableinadequate » in the Atlantic and « unfavourable-bad » in the Mediterranean. Although management measures are in place or planned, they are not sufficient to ensure a favourable conservation status for the bathyal Reefs in the long term., La Directive Habitats-Faune-Flore (92/43/CEE) est un des piliers de la politique de l’Union européenne en faveur de la biodiversité marine. Cette directive impose aux États membres de rapporter périodiquement l’état de conservation et les tendances d’évolution des espèces et habitats d’intérêt communautaire. Pour les habitats, quatre paramètres sont considérés : l’aire de répartition, la surface occupée par l’habitat, l’état de la structure et des fonctions de l’habitat, et les perspectives futures selon les pressions agissant sur l’habitat et selon les mesures de gestion mises en place. Les précédents rapportages pour l’habitat 1170 – Récifs n’ont considéré que partiellement les récifs géologiques et biogènes de l’environnement profond (bathyal). Pour pallier cette lacune, un bilan des connaissances a été réalisé selon les quatre paramètres d’évaluation afin de proposer une évaluation globale de l’habitat Récifs bathyal pour les régions biogéographiques marines Atlantique et Méditerranée françaises. Les évaluations globales de l’état de conservations des Récifs du bathyal indiquent un état de conservation « défavorable-inadéquat » en Atlantique et « défavorable-mauvais » en Méditerranée. Même si des mesures de gestions sont en place ou sont à venir, elles restent insuffisantes pour assurer à long terme un état de conservation favorable de l’habitat Récifs de la zone bathyale.

In the Bay of Biscay, Cold Water Coral (CWC) habitats have been mapped in 24 out of a hundred known submarine canyons. The footprint of ROV or towed-camera transects is small compared to the size of these canyons but still, known CWC habitats totalize a linear of 46 km. The distribution of these habitats, dominated by reef-building scleractinians, antipatharians, alcyonaceans and pennatulids, is however patchy and their median size is small, ranging from 6 to 65 m. While the preservation of these Vulnerable Marine Ecosystems has become essential, all CWC habitats will not be benefit from conservation strategies due to their widespread and patchy distribution. Priorities must thus be defined. Among the criteria for such prioritization, we explore here the ecological role of CWCs as ecosystem engineers.The abundance, the diversity and the taxonomic composition of megafaunal assemblages associated with each CWC habitat are compared. Scleractinian reefs, antipatharians and alcyonaceans on hard substrates as well as pennatulids on soft substrates host different megafaunal assemblages and each should be considered as separate management units. Within each of these three units, we further test the influence of coral cover or coral density, as well as the influence of patch size, on the abundance and the diversity of the associated fauna. In the different habitats, the megafauna shows different patterns according to coral cover, coral density and habitat size, suggesting that aggregations of CWCs do not all have the same ecological role within submarine canyons. The consequences for conservation prioritization are discussed.

The topographical and hydrological complexity of submarine canyons, coupled with high substratum heterogeneity, make them ideal environments for cold-water coral (CWC) habitats. These habitats, including reefs, are thought to provide important functions for many organisms. The canyons incising the continental slope of the Bay of Biscay have distinct morphological differences from the north to the south. CWCs have been reported from this basin in the late 19th century; however, little is known about their present-day distribution, diversity and environmental drivers in the canyons. In this study, the characteristics and distribution of CWC habitats in the submarine canyons of the Bay of Biscay are investigated. Twenty-four canyons and three locations between adjacent canyons were sampled using a Remotely Operated Vehicle (ROV) or a towed camera system. Acquired images were annotated for habitat type (using the CoralFISH classification system), substrate cover and coral identification. Furthermore, the influence of hydrological factors and geomorphology on the CWC distribution was investigated. Eleven coral habitats, formed by 62 morphotypes of scleractinians, gorgonians, antipatharians and seapens, inhabiting hard and/or soft substrate, were observed. The distribution patterns were heterogenous at regional and local scales; the south Bay of Biscay and the southeastern flank favored soft substrate habitats. Biogenic and hard substrate habitats supported higher coral diversities than soft substrate habitats and had similar species compositions. A higher coral species turnover characterized soft substrate habitats. Substrate type was the most important driver of the patterns in both distribution and composition. Observations of coral reefs on steeper areas in the canyons and coral rubble on flatter areas on the interfluve/upper slope, support the hypothesis that canyons serve as refuges, being less accessible to trawling, although natural causes may also contribute to t

Submarine canyons are major geomorphic features of continental margins around the world. Several recent multidisciplinary projects focused on the study of canyons have considerably increased our understanding of their ecological role, the goods, and services they provide to human populations, and the impacts that human activities have on their overall ecological condition. Pressures from human activities include fishing, dumping of land-based mine tailings, and oil and gas extraction. Moreover, hydrodynamic processes of canyons enhance the down-canyon transport of litter. The effects of climate change may modify the intensity of currents. This potential hydrographic change is predicted to impact the structure and functioning of canyon communities as well as affect nutrient supply to the deep-ocean ecosystem. This review not only identifies the ecological status of canyons, and current and future issues for canyon conservation, but also highlights the need for a better understanding of anthropogenic impacts on canyon ecosystems and proposes other research required to inform management measures to protect canyon ecosystems.

Cold-water coral (CWC) habitats can form complex structures which provide refuge, nursery grounds and physical support for a diversity of other living organisms, but despite their ecological significance, CWCs are still vulnerable to human pressures such as fishing, pollution, ocean acidification and global warming Providing coherent and representative conservation of vulnerable marine ecosystems including CWCs is one of the aims of the Marine Protected Areas networks being implemented across European seas and oceans under the EC Habitats Directive, the Marine Strategy Framework Directive and the OSPAR Convention. In order to adequately represent ecosystem diversity these initiatives require a standardised habitat classification that organises the variety of biological assemblages and provides consistent and functional criteria to map them across European Seas (Howell 2010). One such classification system, EUNIS, enables a broad level classification of the deep sea based on abiotic and geomorphological features. More detailed lower biotope-related levels are currently under-developed, particularly with regards deep-water habitats (>200 m depth). This paper proposes a hierarchical CWC biotope classification scheme that could be incorporated by existing classification schemes such as EUNIS. The scheme was developed within the EU FP7 project CoralFISH to capture the variability of CWC habitats identified using a wealth of seafloor imagery datasets from across European seas and oceans. Depending on the resolution of the imagery being interpreted, this hierarchical scheme allows data to be recorded from broad CWC biotope categories down to detailed taxonomy-based levels, thereby providing a flexible yet valuable information level for management. The CWC biotope classification scheme identifies 81 biotopes and highlights the limitations of the classification framework and guidance provided by EUNIS, the EC Habitats Directive, OSPAR and FAO; with limited categories for ide

Marine litter is a matter of increasing concern worldwide, from shallow seas to the open ocean and from beaches to the deep-seafloor. Indeed, the deep sea may be the ultimate repository of a large proportion of litter in the ocean. We used footage acquired with a Remotely Operated Vehicle (ROV) and a towed camera to investigate the distribution and composition of litter in the submarine canyons of the Bay of Biscay. This bay contains many submarine canyons housing Vulnerable Marine Ecosystems (VMEs) such as scleractinian coral habitats. VMEs are considered to be important for fish and they increase the local biodiversity. The objectives of the study were to investigate and discuss: i) litter density, ii) the principal sources of litter, iii) the influence of environmental factors on the distribution of litter, and iv) the impact of litter on benthic communities. Litter was found in all 15 canyons and at three sites on the edge of the continental shelf/canyon, in 25 of 29 dives. The Belle-île and Arcachon Canyons contained the largest amounts of litter, up to 12.6 and 9.5 items 100 images−1 respectively. Plastic items were the most abundant (42%), followed by fishing-related items (16%). The litter had both a maritime and a terrestrial origin. The main sources could be linked to fishing activities, major shipping lanes and river discharges. Litter appeared to accumulate at water depths of 801–1100 m and 1401–1700 m. In the deeper of these two depth ranges, litter accumulated on a geologically structured area, accounting for its high frequency at this depth. A larger number of images taken in areas of coral in the shallower of these two depth ranges may account for the high frequency of litter detection at this depth. A larger number of litter items, including plastic objects in particular, were observed on geological structures and in coral areas than on areas of bare substratum. The distribution of fishing-related items was similar for the various types of relief. L

A long-term lander employing a baited camera system was developed to study temporal variation in the presence of scavenging fish and invertebrates at a cold-water coral community on Galway Mound (Belgica Mound Province, NE Atlantic). The camera system was tested during two successful long-term deployments for periods of 6 and 12 months respectively. The baited system, consisting of two separate video cameras with infrared lights and a bait dispenser with 24 bait positions, recorded more than 15500 clips of 17 seconds, regularly spread over both periods. New bait, consisting of sardines in oil, was offered at regular time intervals, and attracted scavengers over the whole period of deployment, and especially the crab Chaceon affinis did still eat from it till the end of the deployments. However, the attractiveness for some scavengers, i.e. amphipods, diminished quite quickly. In addition to invertebrate scavengers, namely C. affinis, two other crab species, amphipods, a shrimp and a starfish, also 7 species of fish were recorded near the bait, of which Lepidion eques was by far the most common. Though there was no concrete evidence for seasonal patterns, the observations showed substantial temporal variation in the abundance of several species, especially the crabs C. affinis and Bathynectes maravigna and the fish Phycis blennoides. It is concluded that long-term deployments of such a baited camera system can produce novel data. For instance such a system could be employed for monitoring impacts of disturbances on the deep-sea floor (e.g. mining), as we infer that mobile scavengers will be among the first organisms to show a visible reaction to any chemically and physically (noise, vibrations) alteration of the environment similar to a mine canary.

The scleractinian coral Lophelia pertusa has been the focus of deep-sea research since the recognition of the vast extent of coral reefs in North Atlantic waters two decades ago, long after their existence was mentioned by fishermen. These reefs where shown to provide habitat, concentrate biomass and act as feeding or nursery grounds for many species, including those targeted by commercial fisheries. Thus, the attention given to this cold-water coral (CWC) species from researchers and the wider public has increased. Consequently, new research programs triggered research to determine the full extent of the corals geographic distribution and ecological dynamics of “Lophelia reefs”. The present study is based on a systematic standardised sampling design to analyse the distribution and coverage of CWC reefs along European margins from the Bay of Biscay to Iceland. Based on Remotely Operated Vehicle (ROV) image analysis, we report an almost systematic occurrence of Madrepora oculata in association with L. pertusa with similar abundances of both species within explored reefs, despite a tendency of increased abundance of L. pertusa compared to M. oculata toward higher latitudes. This systematic association occasionally reached the colony scale, with “twin” colonies of both species often observed growing next to each other when isolated structures were occurring off-reefs. Finally, several “false chimaera” were observed within reefs, confirming that colonial structures can be “coral bushes” formed by an accumulation of multiple colonies even at the inter-specific scale, with no need for self-recognition mechanisms. Thus, we underline the importance of the hitherto underexplored M. oculata in the Eastern Atlantic, re-establishing a more balanced view that both species and their yet unknown interactions are required to better elucidate the ecology, dynamics and fate of European CWC reefs in a changing environment.

Submarine canyons are major geomorphic features of continental margins around the world. Several recent multidisciplinary projects focused on the study of canyons have considerably increased our understanding of their ecological role, the goods, and services they provide to human populations, and the impacts that human activities have on their overall ecological condition. Pressures from human activities include fishing, dumping of land-based mine tailings, and oil and gas extraction. Moreover, hydrodynamic processes of canyons enhance the down-canyon transport of litter. The effects of climate change may modify the intensity of currents. This potential hydrographic change is predicted to impact the structure and functioning of canyon communities as well as affect nutrient supply to the deep-ocean ecosystem. This review not only identifies the ecological status of canyons, and current and future issues for canyon conservation, but also highlights the need for a better understanding of anthropogenic impacts on canyon ecosystems and proposes other research required to inform management measures to protect canyon ecosystems.

Submarine canyons are major geomorphic features of continental margins around the world. Several recent multidisciplinary projects focused on the study of canyons have considerably increased our understanding of their ecological role, the goods, and services they provide to human populations, and the impacts that human activities have on their overall ecological condition. Pressures from human activities include fishing, dumping of land-based mine tailings, and oil and gas extraction. Moreover, hydrodynamic processes of canyons enhance the down-canyon transport of litter. The effects of climate change may modify the intensity of currents. This potential hydrographic change is predicted to impact the structure and functioning of canyon communities as well as affect nutrient supply to the deep-ocean ecosystem. This review not only identifies the ecological status of canyons, and current and future issues for canyon conservation, but also highlights the need for a better understanding of anthropogenic impacts on canyon ecosystems and proposes other research required to inform management measures to protect canyon ecosystems

Cette réflexion a été réalisée dans le cadre du Bon Etat Ecologique pour la DCSMM (Directive Cadre pour la Stratégie sur le Milieu Marin). Elle est préalable à la construction d'un indicateur de l'Etat Ecologique des communautés benthiques du domaine profond, pour lesquelles il n'existe rien actuellement. Cette réflexion fait suite à une étude bibliographique des indices existants. Voir rapport ci-après: Pedel, L., Fabri, M.C., 2012. Etat de l'art sur les indices existant concernant l'Etat Ecologique des habitats benthiques du domaine profond. DCSMM Bon Etat Ecologique (Ministère de l'Écologie, du Développement Durable, des Transports et du Logement), Ifremer, 1-71.

Ce guide reprend l'ensemble des métriques proposées dans le cadre de la stratégie de surveillance nationale des écosystèmes benthiques profonds évoquées dans le rapport "mesure de l'état écologique des habitats benthiques du domaine bathyal à partir de l'imagerie optique (Sélection de métrique et proposition d'une stratégie de surveillance = stratégie d'échantillonnage)" (Pedel et al. 2013). Il décrit les différentes méthodes d'acquisition vidéo selon les métriques à mesurer: 1.4 Répartition des écosystèmes 1.5 Etendue d'un habitat 1.6 Etat des communautés benthiques (Densité, Taux de couverture, Richesse et composition spécifique, Etat des colonies) 1.3 Structure de taille d'une population Une validation des standards reste à faire avec les pays européens limitrophes pour élaborer une stratégie européenne.

Gomes-Pereira, J. N., Auger, V., Beisiegel, K., Benjamin, R., Bergmann, M., Bowden, D., ... & Edwards, L. (2016). Current and future trends in marine image annotation software. Progress in Oceanography, 149, 106-120. Available here