Tα στερεά απορρίμματα (marine litter) στο θαλάσσιο περιβάλλον (ακτές, πυθμένας, υδάτινη στήλη) αποτελούν πλέον ένα σοβαρό περιβαλλοντικό πρόβλημα για τον παγκόσμιο ωκεανό. Παρά τη σοβαρότητα του προβλήματος μόλις την τελευταία δεκαετία η διεθνής επιστημονική κοινότητα προσεγγίζει με σοβαρότητα το θέμα το οποίο έχει πλέον ενταχθεί στην Ευρωπαϊκή Στρατηγική για τη Θάλασσα (Marine Strategy, Task 10). To Ε.ΘΑ.ΓΕ.Φ.Ω ήδη από το 2008 συντονίζει την Πανελλήνια Εκστρατεία Καθαρισμού των Ελληνικών Ακτών που οργανώνει το Δίκτυο MED SOS. Στο πλαίσιο της παρούσας διπλωματικής εργασίας αναπτύχθηκαν δύο δράσεις: (α) η επεξεργασία δεδομένων που προέκυψαν από τη συμπλήρωση μεγάλου αριθμού Φύλλων Καταγραφής που συμπλήρωσαν χιλιάδες εθελοντές στο πλαίσιο της Πανελλήνιας Εκστρατείας καθαρισμού ακτών για το έτος 2012 και (β) η διαχρονική παρακολούθηση δύο ακτών της Δυτικής Μάνης όσον αφορά στο ρυπαντικό τους φορτίο. Η ταξινόμηση των στερεών απορριμμάτων βασίσθηκε στο υλικό κατασκευής και στην αρχική τους χρήση. Συνολικά 43 ακτές μελετήθηκαν με βάση την επεξεργασία των Φύλλων Καταγραφής και διαπιστώθηκε ότι το πλαστικό είναι το αφθονότερο (43,27%) από τα υλικά των απορριμμάτων ενώ το χαρτί παρουσιάζει αξιοσημείωτα σημαντικό ποσοστό (18,37%), στοιχείο που αποδεικνύει πρόσφατη ρύπανση, λόγω του μικρού χρονικού διαστήματος που χρειάζεται για να αποσυντεθεί. Η πολυδιάστατη στατιστική ανάλυση έδειξε ότι η κυρίαρχη πηγή ρύπανσης είναι η αναψυχή ενώ ακολουθούν ως πηγές η οικιακή, η οικοδομική και η αλιευτική δραστηριότητα. Επιπλέον η επεξεργασία αυτή επέτρεψε τον καθορισμό της επίδρασης της κάθε πηγής σε κάθε ακτή. Ο καθορισμός, με στατιστικά αξιόπιστα κριτήρια, των πηγών ρύπανσης κάθε ακτής από στερεά απορρίμματα αποτελεί τη βάση για τον σχεδιασμό κάθε στρατηγικής για τη μείωση του ρυπαντικού φορτίου στην παράκτια ζώνη. / Nowadays, marine litter is one of the most important environmental problems in the global ocean. In spite of the importance of the problem, only the last ten years has the international science society been approaching this issue with seriousness. Marine litter is integrated in the European Marine Strategy (Marine Strategy, Task 10). The laboratory of the University of Patras (Ε.ΘΑ.ΓΕ.Φ.Ω) has been coordinating the Panhellenic Cleaning Beaches Campaign since 2008. This Campaign is held by MED SOS. Within this study two actions had being developed: (a) the processing of the data that came from thousands of volunteers who worked in the context of the Cleaning Campaign in 2012 and (b) the longitudinal monitoring of the pollution load of two coasts in the Messinian Gulf. The marine litter’s classification was based on their material and their initial use. 43 beaches were studied and the results showed that the most plenty material was plastic (43,27%). Moreover, paper presents noticeable percentage (18,37%), which demonstrates recent pollution. Factor Analysis showed that the main pollution source is leisure, second is building activity, third is fishing and last is domestic activity. Furthermore, this processing led to the determination of each pollution source in every beach. The determination of pollution sources constitutes the basis for the planning of the pollution load’s reduce strategy for the coastal zone.

Στην παρούσα μελέτη εκτιμήθηκαν οι συστάσεις παράκτιων απορριμμάτων σε 28 ελληνικές ακτές για το έτος 2009. Η καταγραφή των απορριμμάτων έγινε από εθελοντές της εκστρατείας εθελοντικών καθαρισμών ακτών και φυσικών περιοχών «Καθαρίστε Τη Μεσόγειο 2009», την οποία συντονίζει η Μη Κυβερνητική Οργάνωση «Δίκτυο Μεσόγειος Σος». Oι εθελοντές ταυτόχρονα με τον καθαρισμό συμπλήρωσαν φύλλο καταγραφής με 2 πίνακες, έναν για τις συστάσεις των απορριμμάτων και έναν για τις αρχικές χρήσεις αυτών. Στα δεδομένα των 28 παραλιών της Ελλάδας εφαρμόσθηκε «περιγραφική Στατιστική» και εκτιμήθηκε ότι το πλαστικό βρίσκεται στην πρώτη των απορριμμάτων (37%), ακολουθώντας το χαρτί (12%) και εν συνεχεία το γυαλί (9%). Τέλος, εφαρμόσθηκε Παραγοντική Ανάλυση στις 11 παραλίες με τα πληρέστερα δεδομένα και τα αποτελέσματα της ερμηνεύτηκαν και προσδιορίστηκαν έτσι οι κυριότερες πηγές ρύπανσης των 11 παραλιών (Χερσαία-Θαλάσσια) καθώς επίσης και οι κυριότερες υποκατηγορίες (Αναψυχή-Αλιεία-Άλλο). / In this present study composition of beach-stranded litter was estimated for 28 Greek beaches for the year 2009. The data were collected with the contribution of volunteers who participated in the “Clean up the Med” campaign of voluntary beach and naturally environmental areas clean ups, which is coordinated in Greece by the Non Government Organization “Med Sos”. The volunteers classified the collected litter item on the basis of the material and initial use. Descriptive Statistical Analysis was applied to the data corresponding to 28 Greek beaches and it was assessed that plastic held the first place among litter (37%) followed by paper (12%) and glass (9%). Finally Factor Analysis was applied to the 11 Greek beaches whose data were more accurately collected. Their results were interpreted thus allowing not only for land based and marine based litter-sources to be determined, but also for the most important subcategories (Recreational, Fishery, Other).

Marine plastics are not just a problem, they are a silent, sinister epidemic. Marine plastics are the largest economic and ecological threat to our marine ecosystems, particularly marine plastics derived from lost and or discarded fishing gear, which affects sensitive marine communities, the chemical composition of the ocean water, and the physical makeup of the seafloor. With 6.4 million tons of marine debris entering our oceans annually, a third of which is lost fishing gear, it is estimated that, by weight, in 2050 there will be an accumulation of more plastic than fish in the ocean (Heath, 2018; Wilcox, 2015). Marine litter derived from plastic fishing gear, primarily passive gear, when lost in the ocean causes a series of consequences to the marine ecosystem, that of which increases when there are high concentrations of fishing activity in the geographic area. Arctic countries have some of the most abundant fisheries, that of which is projected to increase due to anthropogenic climate change. In the context of climate change affecting the Arctic ecosystem, in this thesis, we will review the consequences of plastics derived from fishing gear for the Arctic marine ecosystem, estimate the potential influx of derelict gear plastics originating from data obtained in Alaska and Iceland, and then confidently present effective forms of remediation, prevention, and mitigation strategized from models of sustainable fisheries to resolve the ramifications of lost and or discarded gear in Arctic communities.

Meeresmüll ist ein Problem, das viele verschiedene Meeresarten betrifft, von Säugetieren bis hin zu Wirbellosen. Sie kann mehrere zerstörerische Auswirkungen auf marine Ökosysteme haben und tritt weltweit auf. Das Ziel meiner Forschung in Kerteminde, Dänemark, war es, mögliche physiologische und strukturelle Auswirkungen von marinem Plastikmüll (= Makroplastik) auf Aggregate der Miesmuschelart Mytilus spp. zu verstehen. Es ist bei diesen Tieren üblich, Aggregate in Gezeiten- und flachen subtidalen Lebensräumen zu bilden. Sie bieten verschiedene Ökosystemleistungen, wie die Stabilisierung der Küstenlinie oder die Bereitstellung von Lebensraum für andere Arten. Miesmuscheln sind Filtrierer und tragen so zur biologischen Sanierung bei, die eine wichtige Fähigkeit zur Entfernung von Abfällen aus marinen Ökosystemen darstellt. Angesichts der Ökosystemleistungen, die Muschelaggregate erbringen, ist es entscheidend, alle Faktoren zu verstehen, die dieser Struktur schaden könnten. Mein Fokus lag auf den Auswirkungen von starren und weichen Makroplastikfolien, also Flaschen und Beuteln, da sie weltweit verbreiteten Meeresmüll darstellen. Ich fand heraus, dass Makroplastik tatsächlich die Struktur von Miesmuschelaggregaten beeinflusst. Mein Projekt war Teil einer globalen Studie, organisiert vom GEOMAR Kiel, bei der Masterstudenten aus sechs Ländern die gleichen Experimente durchführten, um makroplastische Effekte auf globaler Ebene zu vergleichen. Ich danke dem GAME-Programm am GEOMAR Kiel für die Finanzierung meiner Forschung sowie Dr. Mark Lenz für die Organisation des Projekts. Außerdem möchte ich dem Meeresbiologischen Forschungszentrum in Kerteminde für die Aufnahme während meiner Forschung danken. / Marine litter is a problem that effects a lot of different marine species, from mammals to invertebrates. It can have several destructing effects on marine ecosystems and is occurring on a global scale. The aim of my research in Kerteminde, Denmark, was to understand potential physiological and structural effects of marine plastic debris (= macroplastic) on aggregates of the blue mussel species Mytilus spp. It is common among these animals to build aggregates in intertidal and shallow subtidal habitats. They provide several ecosystem services, like stabilizing the shoreline or providing habitat for other species. Blue mussels are filter-feeders and so contributing to bioremediation, which is a key capacity to remove wastes from marine ecosystems. Considering the ecosystem services mussel aggregates provide, it is crucial to understand any factors that could harm this structure. My focus laid on the effects of rigid and soft macroplastic films, i.e. bottles and bags, as they represent common marine litter worldwide. I found that macroplastic indeed affects the structure of blue mussel aggregates. My project was part of a global study, organized by GEOMAR Kiel, where Master students from six countries conducted the same experiments to compare macroplastic effects on a global scale. I would like to thank the GAME program at GEOMAR Kiel for financing my research as wells as Dr. Mark Lenz for the organization of the project. Moreover, I want to thank the Marine Biological Research Center in Kerteminde for hosting me during my research.

Microplastic pollution (particles < 5mm) is one of the most widespread impacts from modern society. Here, microplastic impacts were investigated through experimental assessments considering different exposure scenarios using mussels and micro-PVC as models. These aimed to investigate mussels\' physiological signs of stress under acute and chronic exposures and microplastics transference, assimilation and retention along food chains. In acute exposures, PVC intake affected mussels\' physiology over time, also influenced by plastics additives and particle concentration. Interactions among exposure factors (time, presence of additives and concentration) were more relevant than their individual effect, indicating the singularity of each contamination scenario. Long-term contact did not affect mussels, indicating the influence of time to acclimation. Microplastics were not assimilated and retained along food chains, but only biotransferred from prey tissues to predators\' tract, showing the influence of prey contamination on the effectiveness of microplastics biotransference. To evaluate risks in nature, microplastic ingestion was investigated in mussels from the Santos Estuary. Santos Estuary contained microplastics in 75% of sampled mussels, an issue of environmental and human concern. This study illustrated that microplastics impacts on mussels vary with microplastics characteristics, exposure scenario and species vulnerability, highlighting the need for more toxicological and risk evaluation studies. / Os microplásticos (< 5mm) são um dos impactos mais difundidos da sociedade moderna. Aqui, eles foram estudados em ensaios experimentais, considerando diferentes composições de exposição de mexilhões à micro-PVCs. O objetivo foi investigar: sinais fisiológicos de estresse sob exposições aguda e crônica; e transferência, assimilação e retenção de microplásticos em cadeias tróficas. Para avaliar seus potenciais riscos na natureza, a ingestão por mexilhões também foi investigada no Estuário de Santos. As exposições agudas afetaram a fisiologia dos mexilhões, sendo influenciadas pelo tempo e concentração de exposição, e pela presença de aditivos plásticos. Interações entre esses fatores (tempo, concentração e aditivos) foram mais relevantes do que eles individualmente, sugerindo a singularidade dos cenários de poluição. A exposição de longo prazo não afetou os mexilhões, indicando a influência do tempo na aclimatação ao microplástico. O PVC não foi assimilado e retido nas cadeias tróficas, mas biotransferido do tecido das presas para o trato dos predadores, mostrando a influência do estado da presa na efetividade da biotransferência dos microplásticos. Dentre os mexilhões coletados, 75% estavam contaminados, revelando uma importante questão socioambiental. Esse trabalho ilustrou a complexidade dos impactos dos microplásticos para a biota marinha, ressaltando a necessidade de mais estudos sobre seus riscos.

Microplastic pollution (particles < 5mm) is one of the most widespread impacts from modern society. Here, microplastic impacts were investigated through experimental assessments considering different exposure scenarios using mussels and micro-PVC as models. These aimed to investigate mussels\' physiological signs of stress under acute and chronic exposures and microplastics transference, assimilation and retention along food chains. In acute exposures, PVC intake affected mussels\' physiology over time, also influenced by plastics additives and particle concentration. Interactions among exposure factors (time, presence of additives and concentration) were more relevant than their individual effect, indicating the singularity of each contamination scenario. Long-term contact did not affect mussels, indicating the influence of time to acclimation. Microplastics were not assimilated and retained along food chains, but only biotransferred from prey tissues to predators\' tract, showing the influence of prey contamination on the effectiveness of microplastics biotransference. To evaluate risks in nature, microplastic ingestion was investigated in mussels from the Santos Estuary. Santos Estuary contained microplastics in 75% of sampled mussels, an issue of environmental and human concern. This study illustrated that microplastics impacts on mussels vary with microplastics characteristics, exposure scenario and species vulnerability, highlighting the need for more toxicological and risk evaluation studies. / Os microplásticos (< 5mm) são um dos impactos mais difundidos da sociedade moderna. Aqui, eles foram estudados em ensaios experimentais, considerando diferentes composições de exposição de mexilhões à micro-PVCs. O objetivo foi investigar: sinais fisiológicos de estresse sob exposições aguda e crônica; e transferência, assimilação e retenção de microplásticos em cadeias tróficas. Para avaliar seus potenciais riscos na natureza, a ingestão por mexilhões também foi investigada no Estuário de Santos. As exposições agudas afetaram a fisiologia dos mexilhões, sendo influenciadas pelo tempo e concentração de exposição, e pela presença de aditivos plásticos. Interações entre esses fatores (tempo, concentração e aditivos) foram mais relevantes do que eles individualmente, sugerindo a singularidade dos cenários de poluição. A exposição de longo prazo não afetou os mexilhões, indicando a influência do tempo na aclimatação ao microplástico. O PVC não foi assimilado e retido nas cadeias tróficas, mas biotransferido do tecido das presas para o trato dos predadores, mostrando a influência do estado da presa na efetividade da biotransferência dos microplásticos. Dentre os mexilhões coletados, 75% estavam contaminados, revelando uma importante questão socioambiental. Esse trabalho ilustrou a complexidade dos impactos dos microplásticos para a biota marinha, ressaltando a necessidade de mais estudos sobre seus riscos.

Since 1950, the plastic production has increased radically from 1.5 to 280 million tons in 2012. The increased production of plastic has led to oceans becoming more polluted than ever. Micro plastic particles originate from large floating plastic debris by undergoing degradation caused by UV-radiation. Due to their small size, density and colour micro plastic particles resemble marine organisms’ natural prey and are therefore ingested. This report discuss the hypotheses that there are micro plastic particles present in oceans outside of the Costa Rican west coast (hypothesis 1), that the location between the South and North Pacific gyres will result in an accumulation of plastic (hypothesis 2) and that different sampling methods will generate different types of data which makes it difficult to compare results (hypothesis 3). A manta trawl was used to collect samples in size range 1-2mm and they were quantified with a microscope. To simplifying transportation and storing, aluminum foil was used instead of glass jars to collect samples. Thereby the need of transferring material from a glass jar to a flat surface for quantifying with microscope was eliminated. One area contained 56.5 % of all gathered particles together. The result also showed that micro plastic particles are present even in protected areas.

Les déchets plastiques et les produits issus de leurs fragmentations (microplastiques ou « MP », <5mm) représentent une menace globale et persistante pour l'ensemble des écosystèmes marins, du fait de leur facilité d'ingestion par une grande diversité d'espèces marines. La mer Méditerranée, de part sa nature semi-fermée et son littoral anthropisé, est très impactée par cette pollution. Cette thèse a pour objectif de mieux comprendre l'origine et le devenir des MP en mer, et ce, par la mise en place d'une stratégie d’échantillonnage le long du continuum terre-mer, i.e. des sources continentales aux récepteurs marins finaux. Cette approche holistique a été appliquée à l'échelle locale du golfe du Lion (Nord-Ouest de la Méditerranée) à l’ensemble des compartiments côtiers. Les MP ont été retrouvés dans toutes les matrices étudiées (eau, sédiment, dépôtatmosphérique et tissus biologiques) dans des quantités très variables à la fois dans les compartiments et entre les compartiments. Aucune sélection qualitative (forme, taille, polymère et couleur) majeure ne semble s'opérer lors du transfert des MP d'un compartiment à l'autre, et la majorité des MP sont des fibres. Quantitativement, la concentration des MP varie à des échelles temporelles et spatiales très courtes (<1 heure et <1 kilomètre). Si aucune relation claire entre les concentrations en MP et les forçages environnementaux (e.g. précipitation, débit des fleuves, vents, etc.) n'a été observée, les événements de précipitation semblent influencer grandement les quantités de MP transférées entre les compartiments. En extrapolant nos résultats aux bassins-versants du golfe du Lion, 30 ± 20 tonnes de MP se déposeraient via l'atmosphère sur les zones urbainescôtières et 7 ± 10 tonnes de MP seraient transportées par les fleuves vers la Méditerranée, chaque année. L'extrapolation des quantités de MP dans les compartiments marins, semble indiquer que la surface de la mer et les plages ne sont que des compartiments transitoires (< 1 tonne), tandis que les sédiments et la colonne d'eau sont potentiellement plus impactés (jusqu'à 350 tonnes pour les sédiments). De nouvelles données sont nécessaires pour la colonne d'eau et les sédiments pourconfirmer cette hypothèse, mais les résultats laissent penser qu'ils pourraient avoir un rôle majeur dans le stockage des MP. / Anthropogenic litter, particularly plastic litter and their fragments (microplastics or “MPs”; < 5 mm) represent a highly pervasive and persistent global threat to marine ecosystems, as they can be ingested by a wide range of marine species. As a landlocked sea with a high population density, the Mediterranean Sea is highly exposed to marine litter pollution. This thesis aims tounderstand the origin and the future of marine MPs thanks to a holistic approach from terrestrial sources to marine sinks. This strategy was applied at the regional scale of the Gulf of Lion (Northwestern Mediterranean Sea) on all coastal compartments. MPs were observed in every studied matrices (water, sediment, atmospheric fallout) with a high variability within and betweenthe different compartments. No significant qualitative trend seems to occur during the transfer of MPs between compartments and fibers were the most abundant shape found in samples. MP concentrations changed at a short spatial and temporal scale (< 1 hour and < 1 kilometer), overlaying other variabilities (i.e. seasonal or between sites). If no obvious relationship betweenexternal forcing (e.g. precipitations, river flow rates, winds) and MP concentrations was observed, rainfall events seemed to have an important impact on the amount of MPs transferred into the sea. Extrapolating our results to the whole Gulf of Lion watersheds, 30 ± 20 tons of MPs would settle on urban areas and 7 ± 10 tons would be supplied by rivers into the Mediterranean Sea every year. The extrapolation of MP quantities within marine environments seems to indicate that the sea surface and beaches are only transitory compartments (<1 ton) whereas sea floor and water column couldbe more impacted (up to 350 tons for marine sediment). New data on water column and marine sediments are needed to confirm this hypothesis, but those results suggest that both latter compartments could be major sinks for marine MPs.

Les habitats de coraux d’eau froide formés par des scléractiniaires coloniaux, des gorgones, des antipathaires et des pennatules sont des hotspots de biodiversité et de biomasse. Ils fournissent des fonctions importantes, comme des refuges et des zones d’alimentation, pour d’autres organismes. Mais, ils sont également vulnérables aux activités humaines, parce qu’ils sont fragiles, croissent lentement et atteignent des records de longévité. Dans les canyons sous-marins, le relief tourmenté, l’hydrodynamisme et l’hétérogénéité des substrats offrent des conditions environnementales propices au développement des habitats coralliens. Dans le Golfe de Gascogne, les coraux d’eau froide sont connus depuis la fin du 19e siècle, mais leur distribution, leur densité et leur rôle fonctionnel avaient été très peu étudiés.Pour augmenter cette connaissance, 24 canyons sous-marins et 3 sites sur l’interfluve/haut de pente contiguë aux canyons adjacents ont été visités par un ROV et une caméra tractée pendant 46 plongées au cours de 7 campagnes océanographiques. Les habitats coralliens définis par le système de classification CoralFISH ont été cartographiés à partir des images prises par les engins sous-marins puis la faune associée, les types de substrat et les déchets ont été annotés.Onze habitats coralliens et 62 morphotypes de coraux ont été observés dans les canyons sous-marins du Golfe de Gascogne hébergeant 191 morphotypes de faune associée, dont 160 morphotypes uniques. Les patrons de distribution à l’échelle locale et à l’échelle régionale pourraient être liés aux régimes hydrodynamiques et sédimentaires. Le type de substrat était important pour les assemblages de coraux et leurs faunes associées, distinguant les habitats biogéniques, sur substrat dur et sur substrat meuble. Les assemblages de coraux étaient similaires entre habitats biogéniques et habitats sur substrat dur, mais la faune associées était plus abondante et diversifiée sur les habitats biogéniques. La diversité-alpha, -beta et –gamma étaient étonnement élevée sur les habitats coralliens sur substrat meuble, égalant ou dépassant la diversité des habitats biogéniques.Les déchets marins étaient abondants et principalement composés de plastiques et de matériels de pêche. Ces déchets pourraient impacter les habitats coralliens : ils ont été trouvés à des profondeurs similaires et les déchets étaient piégés par des reliefs créés par des structures biologiques et géologiques. L’ocurrence des récifs de coraux préférentiellement sur les pentes plus abruptes des canyons sous-marins tandis que les débris de coraux sont plus fréquents sur des aires plus plates de l’interfluve ou du haut de pente, pourraient indiquer un impact de la pêche.Cette étude a contribué à l’initiative en cours de création d’un réseau Natura 2000 qui protégera à terme l’habitat « récif » dont les habitats coralliens biogéniques et sur substrat dur, mais pas les habitats coralliens sur substrat meuble. Pour ces derniers, un complément d’étude et d’autres stratégies de préservation seront nécessaires. / Cold-water coral (CWC) habitats formed by colonial scleractinians, gorgonians, antipatharians and sea pens are biodiversity and biomass hotspots that provide important functions, such as shelter and feeding grounds, to other organisms. But, they are also vulnerable to human activities, because they are long-lived, grow slowly and have a low resistance. Submarine canyons may offer the environmental conditions needed for CWC habitat development, due to their steep topography, complex hydrodynamics and substrate heterogeneity. In the Bay of Biscay, which margin is incised by hundreds of canyons, CWCs are known to exist since the late 19th century, but their distribution, density and functional role remained largely unknown, which impaired their preservation.To increase this knowledge, 24 canyons and three locations between adjacent canyons were visited with an ROV and a towed camera system during 46 dives on 7 cruises. Images were analysed for CWC habitats using the CoralFISH classification system. Within these habitats, corals, associated fauna were identified and substrate cover measured. Litter was identified in 15 out of 24 canyons.Eleven coral habitats constructed by 62 coral morphotypes were observed in the canyons of the Bay of Biscay hosting 191 associated megafaunal morphotypes, including 160 unique morphotypes. The distribution patterns at regional and local scales could be linked to hydrodynamics and sedimentary regimes. Substrate type was an important driver for coral and associated faunal assemblages, distinguishing biogenic, hard substrate and soft substrate habitats. Coral assemblages were similar between biogenic and hard substrate habitats, but the associated fauna was more abundant and diverse on biogenic habitats. The alpha, beta and gamma diversity was surprisingly high on soft substrate habitats, equalling or exceeding that of biogenic habitats.Marine litter was abundant and was mainly composed of plastic items and fishing gear. Litter could co-occur with CWCs and impact them: litter and most CWC habitats were observed at similar water depths and litter was more abundant in areas with a seafloor relief created by biological or geological features. Observations of coral reefs on steeper areas in the canyons and coral debris on flatter areas on the interfluve/upper slope may indicate a potential impact of the fishing industry. This study supports the ongoing effort to create a Natura 2000 network that will protect biogenic and hard substrate habitats, but also points out the need to develop a framework for the preservation of coral habitats on soft substrate.