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The deep southern Adriatic Sea is home of widespread cold-water coral colonization (Madrepora oculata, Lophelia pertusa, Desmophyllum dianthus) which is at present limited by large to its western (Apulian) margin and central part, including the Bari Canyon system. On the contrary, the eastern side is today almost deprived of significant coral growth and this asymmetrical distribution has been ascribed primarily to the action of the North Adriatic Dense Water (NAdDW) that impinges more efficiently on the Apulian margin. The collection of subfossil specimens of M. oculata, L. pertusa and D. dianthus provided the very first dates for cold-water coral colonization along the eastern margin. Once combined with known distribution of live cold-water corals and fossil occurrences in the southern Adriatic Sea, uranium-series dating provides evidence of (i) coral presence in the southeastern Adriatic during the Last Glacial Maximum (LGM), followed by (ii) a time of basin-wide colonization after the post-Last Glacial Maximum and encompassing the Younger Dryas, (iii) another time of undocumented coral presence with the onset of Sapropel S1. Perturbations of the thermohaline circulation in this sector of the Mediterranean basin might have governed the presence and demise of the resident cold-water coral populations interfering with strength and trajectories of main water masses. It is hypothesized that the achievement of the current asymmetrical distribution did occur since the end of S1 protracting to present time. The post-S1 reorganization likely brought to the current hydrological situation where the influence of NAdDW prevails in the western side and corals are doing at best on its trajectory. The scarcity of datable material makes the proposed scenario open to debate and in need of further supporting evidence.

In this work, we present preliminary results of the first application in the Mediterranean Sea of a hyperspectral camera, a device commonly used for satellite or airborne remote sensing, adapted for the underwater environment. The spectral analysis was carried out on hyperspectral images acquired in two different environmental settings in the southern Adriatic Sea. This new technology shows high potentialities of application for benthic habitat mapping and monitoring.

Coral reefs are declining worldwide as a result of the effects of multiple natural and anthropogenic stressors, including regional-scale temperature-induced coral bleaching. Such events have caused significant coral mortality, leading to an evident structural collapse of reefs and shifts in associated benthic communities. In this scenario, reasonable mapping techniques and best practices are critical to improving data collection to describe spatial and temporal patterns of coral reefs after a significant bleaching impact. Our study employed the potential of a consumer-grade drone, coupled with structure from motion and object-based image analysis to investigate for the first time a tool to monitor changes in substrate composition and the associated deterioration in reef environments in a Maldivian shallow-water coral reef. Three key substrate types (hard coral, coral rubble and sand) were detected with high accuracy on high-resolution orthomosaics collected from four sub-areas. Multi-temporal acquisition of UAV data allowed us to compare the classified maps over time (February 2017, November 2018) and obtain evidence of the relevant deterioration in structural complexity of flat reef environments that occurred after the 2016 mass bleaching event. We believe that our proposed methodology offers a cost-effective procedure that is well suited to generate maps for the long-term monitoring of changes in substrate type and reef complexity in shallow water

The Mediterranean environment stressors and their effect on the trophic state require the assessment of interconnection between land-based drivers, the real and potential pressures and impacts. To achieve this, it is necessary to consider as well, several social and economic factors that may influence decision-making around land-sea planning and the management of nutrients, pollutants, and sediment transport. Moreover, once the ecological situation is characterized, it is advisable to establish the linking between the natural systems and the ecosystem services. In the Mediterranean Sea, it fairly demonstrated by ecosystem-based management approaches and the literature that human activities can affect the water column, seafloor, and biodiversity, among others. Moreover, it is a fact that these issues require a detailed piece of knowledge of a wide variety of geological, sociological, economical and biological variables, among others. Those variables are dependent on prioritizes actions. One of them is the monitoring, mitigation, and control of the eutrophication processes, which needs the deconstruction of the Integrated Coastal Zones Management (ICZM) approach into priorities actions, in accordance with the multi-level water characteristics and their interconnection, i.e., the coastal zone dynamics, and the multilevel governance.

In the Mediterranean Sea, crustose coralline algae form endemic algal reefs known as Coralligenous (C) build-ups. The high degree of complexity that C can reach through time creates notable environmental heterogeneity making C a major hotspot of biodiversity for the Mediterranean basin. C build-up can variably modify the submarine environment by affecting the evolution of submerged landforms, although its role is still far from being systematically defined. Our work proposes a new, ad-hoc semi-automated, GIS-based methodology to map the distribution of C build-ups in shallow coastal waters using high-resolution bathymetric data, collected on a sector of the southern Apulian continental shelf (Southern Adriatic Sea, Italy). Our results quantitatively define the 3D distribution of C in terms of area and volume, estimating more than 103,000 build-ups, covering an area of roughly 305,200 m2, for a total volume of 315,700 m3. Our work firstly combines acoustic survey techniques and geomorphometric analysis to develop innovative approaches for eco-geomorphological studies. The obtained results can contribute to a better definition of the ocean carbon budget, and to the monitoring of local anthropogenic impacts (e.g., bottom trawling damage) and global changes, like ocean warming and acidification. These can affect the structural complexity and total volume of carbonate deposits characterizing the Mediterranean benthic environment.

Within the framework of the BioMAP Project (BIOcostruzioni Marine in Puglia, - P.O. FESR 2007/2013), new acoustic data were acquired in order to identify and locate Coralligenous Habitats (CHs) along the Apulian continental shelf (South Adriatic Sea – Northern Ionian Sea). The analysis of the multibeam echosounder (MBES) dataset allowed us to identify different morphological expression of CHs. Geomorphometric techniques have been applied on the MBES data in order to (1) figure out relationships between the observed morphologies and the associated habitat distribution and (2) quantify the total volume of selected Coralligenous build-ups. Our results were obtained applying a quantitative analytical approach, focusing on the exploitation of the full potential of seafloor data sets in an objective manner. Our approach can be even used to monitor future changes, from anthropogenic impacts (e.g., bottom trawl damage) to the impacts of global change including ocean warming and acidification that can affect the structural complexity and total volume of carbonate deposits characterising the Mediterranean benthic environment.

Bathymetric surveying in shallow water can be performed by multiple ways: traditionally using a vessel but also techniques like LIDAR, satellite bathymetry or hovercrafts (and smaller) are used. For ultra-shallow bathymetry, data acquisition, using either singlebeam or multibeam echosounder systems, often present difficulties in obtaining reliable data where submerged obstacles are present; whereas the use of LIDAR technology or satellites data implies relatively high-costs. Multiple studies on land environment have validated the accuracy of Structure from Motion (SfM) techniques for high-resolution 3-dimensional (3D) topographic reconstruction and analysis, and in some cases found SfM to be highly comparable to substantially more expensive LIDAR techniques. In the last 5 years this methodology start to be applied in ultra-shallow marine environment, using the collection of videos or still images by underwater cameras along snorkelling transect, especially on coral reefs, where ship-based survey are unfeasible. The small spatial extent of the resulting 3D models, in this peculiar marine setting, is the main limit of this technique. Our methodology attempt to increase the coverage of SfM techniques in ultra-shallow water environment coupling the snorkelling video transects with an Unmanned Aerial Vehicle (UAV) survey in order to obtain: (1) a complete submetrical scale DEM (Digital Elevation Model) on reef-flat areas, and (2) provide unique opportunities to better quantify topography, rugosity and other structural characteristics of this ultra-shallow marine environment. This study utilized SfM 3D reconstruction software tools to create textured mesh models of a coral reef flat area of a small Maldivian island (Magoodhoo Island, Faafu Atoll) and used a proper GIS-based tool to further extract geomorphometric parameters from the surveyed area, providing evidence of the adeptness of the survey design for a number of applications

Coralligenous bioconstructions represent an outstanding example of calcareous build-ups of biogenic origin of the Mediterranean Sea. They provide sensitive and vulnerable habitats actually included in the list of endangered habitats by governmental organizations and conservation agencies (e.g. OSPAR; red list habitats). They are especially sensitive to the ongoing global change (i.e. ocean acidification) that can produces a negative impact on the calcification of the organisms’ skeleton of which they are formed (mainly calcareous algae and invertebrates). The extent to which the coralligenous bioconstructions can modify the submarine environment, affecting the evolution of submerged landforms is extremely variable. Within the framework of the BIOMaP Project (BIOcostruzioni Marine in Puglia, - P.O. FESR 2007/2013), promoted by Puglia region, Italy, new high resolution acoustic data were acquired in order to identify and locate Coralligenous Habitats along the Apulian continental shelf (South Adriatic Sea – Northern Ionian Sea), from 10 down to 100 meters of water depth, in 21 Site of Community Interest and 3 Marine Protected Areas. The dataset covered an area of 1000 km2 and was obtained through the use of MultiBeam Echosounder Systems and Side Scan Sonars. Ground-truthing were collected by 3 ROV dives (Prometeo ROV) and more than 30 underwater camera transects. The present study is based on a new experimental methodology designed to analyze multibeam data by means of geomorphometric analyisis in order to (1) figure out relationships between the observed morphologies and the associated distribution and (2) quantify the total volume of selected Coralligenous build-ups. Our work underlines the importance of combining acoustic survey techniques and geomorphometric analysis in order to offer quantitative information for a new understanding of the importance of Coralligenous Habitat as carbonate deposits of the Mediterranean shelf

Nell’ambito del programma di ricerca multidisciplinare MESC (PRIN2006) sono state rilevate diverse morfologie legate alla fuoriuscita di fluidi dal fondo, ubicate lungo la parte esterna della piattaforma, nel settore occidentale del Plateau di Malta (Canale di Sicilia; Savini et alii 2009; Cangemi et alii, 2010). In particolare, Savini et alii (2009) hanno descritto due principali tipologie di strutture: (1) vulcani di fango quiescenti e (2) ridges. L’utilizzo di sensori remoti (ecoscandaglio multifascio, sonar a scansione laterale, profilatore del substrato) e l’acquisizione di filmati video (tramite veicoli subacquei filoguidati) hanno permesso d’individuare tali ridges, e di descriverne alcuni aspetti biologici, litologici e stratigrafici (Savini et alii, 2009), ma solo un dettagliato studio multidisciplinare di alcuni campioni prelevati all’interno di tali strutture, ha potuto meglio chiarire la natura e l’origine di queste morfologie. Nel ridge più esteso sono state prelevate due carote di sedimento tramite carotiere a gravità. La carota GC01-MV02 è stata prelevata sul fianco del ridge, ad una profondità di 141 m, ed è lunga 176 cm. La carota GC02-MV03 è stata prelevata a 144 m di profondità, esattamente sul top del ridge ed è lunga 81 cm. Sulle due carote sono stati condotti studi sedimentologici, paleontologici (paleoecologia e biostratigrafia) e mineralogici. Infine sono state condotte datazioni U/Th presso l’Università di Berna (Svizzera). Per la carota GC01-MV02 sono stati identificati 2582 esemplari di molluschi e brachiopodi appartenenti a 209 specie, mentre per la carota GC01-MV03 1388 esemplari appartenenti a 128 specie. Entrambe le carote sono costituite da una frazione fangosa nella parte sommitale, caratterizzata dalla presenza di specie indicative di biocenosi circalitorali tra cui Detritico Costiero (DC), Fanghi Terrigeni Costieri (VTC) e Fanghi Profondi (VP). Spostandosi verso la porzione basale di entrambe le carote aumenta la frazione

In tropical coral reef environments, surveying techniques that provide high-resolution data on the seafloor morphology are traditionally associated with high logistical costs (USV, LIDAR or satellite bathymetry) and with high diculties in obtaining shallow bathymetry where submerged hazards are present. Acoustic methods in these environments (using either singlebeam or multibeam echosounders systems) require a big number of routes to reach a high-resolution bathymetry and in addition, submerged obstacles limit their operability. Several studies on land environment have conrmed the accuracy of Structure from Motion (SfM) techniques for high-resolution 3-dimensional (3D) topographic reconstruction and analysis, and in some cases found SfM to be equivalent to LIDAR techniques. In the last 5 years this methodology started to be applied in ultra-shallow marine environment, using snorkeling transect with underwater cameras on coral reefs, where ship-based survey are unfeasible. The small spatial extent of the resulting 3D models, in this particular underwater context, is the main limit of this technique. Our methodology aim to increase the coverage of SfM techniques in ultra-shallow water environment coupling the snorkelling video transect with a commercial Unmanned Aerial Vehicle (UAV) survey in order to obtain: (1) a complete sub-metrical resolution DEM (Digital Elevation Model), and (2) provide unique opportunities to better quantify topography, rugosity and other structural characteristics of this peculiar marine environment. This study utilized SfM 3D reconstruction software tools to create DEM of a coral reef of a small Maldivian island (Magoodhoo Island, Faafu Atoll) and used a proper GIS-based tool to extract geomorphometric parameters. The use of geomorphometric analysis on the resulting DEMs allowed to quantitatively asses the structural complexity of the surveyed reef, that can be integrated with other physiological and ecological parameters to increase our kno

Hyperspectral imagers enable the collection of high-resolution spectral images exploitable for the supervised classification of habitats and objects of interest (OOI). Although this is a well-established technology for the study of subaerial environments, Ecotone AS has developed an underwater hyperspectral imager (UHI) system to explore the properties of the seafloor. The aim of the project is to evaluate the potential of this instrument for mapping and monitoring benthic habitats in shallow and deep-water environments. For the first time, we tested this system at two sites in the Southern Adriatic Sea (Mediterranean Sea): the cold-water coral (CWC) habitat in the Bari Canyon and the Coralligenous habitat off Brindisi. We created a spectral library for each site, considering the different substrates and the main OOI reaching, where possible, the lower taxonomic rank. We applied the spectral angle mapper (SAM) supervised classification to map the areal extent of the Coralligenous and to recognize the major CWC habitat-formers. Despite some technical problems, the first results demonstrate the suitability of the UHI camera for habitat mapping and seabed monitoring, through the achievement of quantifiable and repeatable classifications.

In the framework of the Italian multidisciplinary research project “Mud volcanoes Ecosystem study - Sicily Channel” cores MV02_GC01 and MV03_GC02 were recovered from a tabular relief at 140 m water depth, to investigate the nature of such uncommon shallow seep-related morphology trough micro- and macro-paleontological, mineralogical, sedimentological and geochronological analyses. Both cores record muddy surficial sedimentation, hosting a strictly circalittoral molluskan death assemblage typical of mobile substrate, coherent with the present-day seafloor depth and environment. The core bottom recovered a biogenic framework, in which the molluskan fossil assemblage is characteristic of shallow-water, possibly infralittoral, representing a past sea level low stand. The biogenic framework shows structure and composition that are similar to present day algal reefs indicated as coralligenous build-ups. Both cores recorded the Holocene transgression. Core MV02_GC01 is longer and its basal section records cobbles and pebbles of both terrigenous and biogenic origin partially covered by a dark patina, and finely preserved Halimeda sp. fragments. The dark patina reveals a fibrous nature, often containing framboid pyrite crystals, ankerite, but no organic matter. We interpret the dark patina level as the last lowstand, possible forming in a lagoon-like paleoenvironment. Below such level, another coralligenous build-up occurs, U/Th dated to MIS 6, in agreement with the available seismic interpretation. The tabular relief lays up to 10 m above the surrounding seafloor and reveals a complex inner architecture, in which at least two generations of coralligenous build-ups shaped its geomorphological development, and the local tectonic activity contributed to its uplift.

In the present work, we applied the use of an Unmanned Aerial Vehicle (UAV) - a quadcopter - and the Aerial Structure from Motion digital photogrammetry image processing technique (ASfM) to study volcano-tectonics and tectonic features in an active Icelandic rift. Data have been collected in order to evaluate the Holocene deformation in the Northern Volcanic Zone of Iceland. We mapped 397 structures, mainly related to extension fractures and subordinately normal faults in the Theistareykir Fissure Swarm, obtaining 1098 and 21 structural data, respectively. This allowed to reconstruct an overall spreading direction of N108° during Holocene times, and to calculate a stretch of 1.013 regarding 8–10 ka old lava units. Deformation in the area is related to both dyke intrusions and extensional tectonics. Furthermore, detailed geological-structural field and UAV surveys were also performed in two test areas in order to determine data accuracy and the associated reliability of this approach. In addition to the above, different flight heights were tested, suggesting that photo collection with a 12.4 MPx camera at 100 m is efficient to study fracture dilation and kinematics.

Management and planning of coastal and marine areas are complex processes that are more and more required to effectively support a coordinated development of socio-economic activities. In managing coastal and marine activities, it is important to have good governance with assistant from spatial data infrastructure (SDI), to ensure sustainable planning and development of marine area. GIS and related technologies are becoming increasingly used to aid in the administration and management of the marine environment. This article describes the implementation of SDI, demonstrating how an interoperable system can provide strong support in implementing the integrated coastal and marine management. It also focuses on the degree of GIS implementation, the issues, the limitation and engagement in establishing SDI-ICMM in Tunisia.

Rhodolith beds are priority marine benthic habitats for the European Community, because of their relevance as biodiversity hotspots and their role in the carbonate budget. The high-Mg calcite calcified thalli promote their preservation through time, resulting in their common occurrence in the fossil record, thus making rhodoliths a significant archive of past environmental and climate changes. The present temperate Mediterranean Sea is home to rhodolith-rich up to rhodolith-dominated habitats which have been targeted over the years for ecological research and management actions. Furthermore, the Mediterranean Basin hosts an important fossil legacy of rhodolith beds that formed under contrasting climatic scenarios since the Neogene. Most examples of Mediterranean rhodolith beds lay within the depth range (30-75 m), while far less is known about deeper occurrences. An outstanding rhodolith bed has been recently identified off the Egadi Archipelago (70-95 m, Central Mediterranean Sea) in the frame of the Italian Marine Strategy Framework Directive project. The rhodolith bed carpets an area >7 km2 between Marettimo and Favignana Islands (Egadi Archipelago), with a cover of live rhodoliths up to 95%. The dominant rhodolith morphotype is pralines, ellipsoidal to discoidal in shape (average size 11 mm, maximum size 31 mm) associated with biogenic gravelly-sand. They present both seafloor bedforms (megaripples and ripples) and frequent bioturbations by epifaunal and semi-infaunal sea urchins. Old algal nodules, biogenic sand/mud, or, less frequently, terrigenous particles serve as nucleus of individual rhodoliths. Living calcareous algae are Lithothamnion valens, L. cf. minervae, Phymatolithon lenormandii, and Lithothamnion spp. The latter characterize also the dead algal association close to the nucleus, with the subordinate presence of Lithophyllum sp. Benthic fauna corresponds to the circalittoral environment, with exclusive species of the Coastal Detritic biocoenosis or

In the Mediterranean, build-ups (created by coralline algae, Cladocora caespitosa, deep-water corals, vermetids, polychaetes and bacteria) and rhodolith beds are important hot-spots of biodiversity. Being severely threatened by anthropogenic impact and climate change, they have been included in international directives on environmental protection. This work wants to support the ongoing research on modern bioconstructions by providing further data on the long-term effects of environmental factors on these habitats. Our results are based on the analysis of the existing literature on the outcropping Quaternary successions of the Adriatic and Ionian coasts of peninsular Italy. The existing reports of build-ups and rhodalgal carbonates have been summarized in an homogeneous data-set and then studied to highlight distribution patterns in space and time. The analyses consistently outlined the importance of sedimentation rate in controlling the general distribution of build-ups and rhodalgal carbonates. The majority of the reports is concentrated south of the Gargano, where the sediment-load of the rivers is small. The majority of the reports is related to coralline algae, suggesting that they were the main carbonate producers during the period. C. caespitosa general distribution is mainly controlled by temperature, with most of the occurrences dating back to the warm periods of the late Ionian and of the Tarantian. Large build-ups of Cladocora are restricted to embayments and gulfs well-protected against storm waves. The distribution of the outcrops of deep-water corals is biased by the geological setting. A remarkable uplift is necessary to bring these corals from their original deep-water setting to elevated areas onshore. Consequently, most of the outcrops are in Southern Calabria which is characterized by a strong Quaternary uplift. Chemosynthetic build-ups, intertidal bioconstructions (made by vermetids, polychaetes or coralline algae), as well as stromatolites, are r

The aim of this work is to demonstrate the benefits of digital surface-quantification and species identification in the study of coralline algae. Within the well-constrained context of the Miocene Sommières Basin (Southern France), whose sedimentological and paleontological setting has been reconstructed by previous researches, the abundance of coralline algae is estimated through quantification of the area occupied by the different species, which are thoroughly described in order to make future taxonomic-revisions as easy as possible. Coralline distribution patterns are studied along a bathymetric gradient to assess the response of the major groups and of the different species to variations in water depth. Surface quantification highlights clear trends both at the species level and higher taxonomic ranks, showing that coralline algae can be a quite accurate instrument in paleoenvironmental reconstructions. Among the clearly identified species, Lithophyllum sp. A, Sporolithon sp. A, and Spongites fruticulosus prefer shallow-water; Mesophyllum roveretoi dominates at intermediate depth together with Lithothamnion ponzonense, while Phymatolithon sp. A occurs at the lower limit of the photic zone. The approach presented here can be applied to a variety of different contexts, providing a powerful instrument for the interpretation of coralline-algal associations.

The Maldives are situated in the remote equatorial Indian Ocean, covering 900 km from north to south. The 26 coral atolls forming the archipelago are composed of sand and coral with a maximum height of about 2.30 m above the mean sea level. Periodic flooding from storm surges and the frequent freshwater scarcity are perceived by the population and the economic operators as the major environmental stresses. Moreover, the strong dependence on imported fossil fuels increases, even more, the environmental concerns. Diesel, in fact, still represents the main source of power generation, typically through privately managed small diesel sets. The real challenge for this area is to promote the environmental quality with socioeconomic growth. The present study aims to evaluate the strategic effectiveness to face these issues by wave and offshore wind energy. Resources using a 10-year hindcast dataset are here examined. The annual offshore wave power was found to range between 8.46 kW/m and 12.75 kW/m, while the 10 m and 100 m mean wind power density is respectively 0.08 kW/m2 and 0.16 kW/m2. Based on these results, an environmentally and socio-economically sustainable best-case scenario is constructed and two atoll islands (Malè and Magoodhoo) are specifically investigated. As a result, multifunctional structures and multi-use systems, which combine power generation, desalinization and coastal defence, are strongly recommended.

In the framework of Mediterranean marine benthic zonation, coralligenous (C) is a circalittoral biocenotic complex forming a new solid substrate, mainly produced by the overgrowth and accumulation of calcareous encrusting algae in dim light conditions, and consisting of tridimensional biogenic build-ups. As other benthic bio-constructions, it contributes to seascape formation through geological times, causing geomorphological changes of the seafloor. In the Mediterranean Sea it forms large structures that may be up to 4 m high and greater than 50 m in lateral continuity. Marine bionomists consider the substrate of C to be a key factor in distinguishing the C d'horizon inferieur de la roche littorale, always on a pre-existing hard substrate, from the C de plateau. Originally, the latter was indicated as a biogenic framework developed from the coalescence of rhodoliths; then it was generally indicated as forming a new solid substrate on an originally mobile substrate. However, given the diculty to investigate the type of substrate of C, some authors suggested that some C de plateau frameworks could have grown on submarine rocky outcrops. C produces various morphotypes on the seafloor, not exhaustively categorized yet. Several terms are used to dene C morphotypes, but their application through dierent geological and environmental settings still remains inconsistent. Only two general categories are reported: 1) banks { at over more or less horizontal substrata, and 2) rims { structures on submarine vertical clis or surrounding the opening of submarine caves. Apulian C is known in literature since decades. Large areas of the Apulian continental shelf have been investigated by acoustic methods from the coastline down to 100 m water depth, in the framework of the BIOMAP project and of a commercial survey. Collected remote data (Multibeam echosounder, Side Scan Sonar and Chirp/Sub Bottom Proler) have been ground-truthed by ROV and camera inspections. Seafloor mapping techni

Coralligenous has a relevant role in submarine landscape formation and demise through geological times, producing various morphotypes on the seafloor. Several terms are used to define coralligenous morphotypes, but their application through different geological and environmental settings still remains inconsistent. Through a systematic analysis of seafloor acoustic remote data (multibeam, side scan sonar and subbottom profiler) along Apulia continental shelf, ground-truthed by video observations and direct sampling, we detected a number of coralligenous morpho-acoustic facies as 0.2 up to 4 m topographic reliefs with steep flanks and a rigid inhomogeneous biogenic framework, characterized by medium to strong SSS backscatter and a variable plan-view geometry. The observed pattern led to the identification of coralligenous meso- and macrohabitat in which the biogenic frameworks (i.e. coralligenous) prevail as sole biocommunity on the seafloor or are associated with other type of habitats: (i) coralligenous sensu stricto, (ii) coralligenous and detritic bottom, (iii) coralligenous and muddy bottom, (iv) coralligenous and Posidonia meadow. Finally we improve the geomorphological definition of bank, proposing this new descriptive rigorous categorization for coralligenous morphotypes on sub-horizontal substrate: 1) tabular bank, 2) discrete relief, and 3) hybrid bank.