Red Coral Research Articles

Polyp longevity in a precious gorgonian coral: hints toward a demographic approach to polyp dynamics

In this paper, we investigated the age distribution and dynamics of polyps in the slow-growing and long-lived gorgonian Corallium rubrum (the Mediterranean red coral), applying an a posteriori demographic approach by considering each colony as a population of polyps. In the Mediterranean red coral, new polyps emerge from the coenenchyme in different regions of the colony and their budding rate depends on the age of branches. The age of polyps, branches and colonies were estimated using the organic-matter-staining dating method on thin sections of the colony skeleton. The median age and maximum life span of polyps were 4 and 12 years suggesting the presence of senescence processes: thus a colony renews several times its polyps during life cycle. Polyps were divided into annual age classes, and their mortality rates calculated. The polyp age distribution was then used to construct a mortality table and an algebraic transition matrix based on the age at death of 234 polyps. Finally, the polyp budding rate of a young, unbranched colony was calculated, and polyp temporal dynamics simulated. These findings represent the first steps for developing demographic models able to describe polyp dynamics of old and highly branched colonies.

DNA fingerprinting: an effective tool for taxonomic identification of precious corals in jewelry

Precious coral species have been used to produce jewelry and ornaments since antiquity. Due to the high value and demand for corals, some coral beds have been heavily fished over past centuries. Fishing and international trade regulations were put in place to regulate fishing practices in recent decades. To this date, the control of precious coral exploitation and enforcement of trade rules have been somewhat impaired by the fact that different species of worked coral samples can be extremely difficult to distinguish, even for trained experts. Here, we developed methods to use DNA recovered from precious coral samples worked for jewelry to identify their species. We evaluated purity and quantity of DNA extracted using five different techniques. Then, a minimally invasive sampling protocol was tested, which allowed genetic analysis without compromising the value of the worked coral objects.The best performing DNA extraction technique applies decalcification of the skeletal material with EDTA in the presence of laurylsarcosyl and proteinase, and purification of the DNA with a commercial silica membrane. This method yielded pure DNA in all cases using 100 mg coral material and in over half of the cases when using “quasi non-destructive” sampling with sampled material amounts as low as 2.3 mg. Sequence data of the recovered DNA gave an indication that the range of precious coral species present in the trade is broader than previously anticipated.

Wolves in sheep’s clothing: three new cases of aggressive mimicry in Red Sea coral reef fishes

ABSTRACT Here we document three cases of mimicry in coral reef fishes not previously reported in the literature involving two groupers (Epinephelus leucogrammicus and Plectropomus marisrubri) and a soapfish (Diploprion drachi) as mimics, and two wrasses (Larabicus quadrilineatus and Cheilinus quinquecinctus) and a blenny (Meiacanthus nigrolineatus) as models. All three cases are of aggressive mimicry, with a predatory species mimicking a harmless one, and in one of the cases, the mimicry is also Müllerian, where both the predator and harmless species are unpalatable.

Assessing the impact of population decline on mating system in the overexploited Mediterranean red coral

Abstract Understanding the interactions among demographic parameters, mating system and population dynamics is key to predict the response of populations to global change. The Mediterranean red coral is a precious octocoral suffering from population decline due to overfishing and warming‐driven mass mortality events. While the demographic consequences of these two pressures are well characterized, little is known regarding their impact on population dynamics and evolution of red coral populations. The main objective of this study was to fill this gap focusing more particularly on mating pattern and genetic drift. Combining sibship and progeny arrays analyses, a genetic characterization of the red coral mating system was conducted. In addition, a synchronic approach was developed comparing mating patterns in two populations with contrasting demographic patterns: a pristine‐like population and a declining population. The results show that polyandry is likely to be the norm in red coral. The similar patterns of genetic diversity between adults and larvae combined with the lack of differential reproductive success among putative fathers did not support significant sweepstakes effects during larval production. While instantaneous biparental inbreeding was detected, no long‐term inbreeding was observed even in the declining population. Mating patterns and effective population sizes in the two populations were not statistically different. Nevertheless, a trend towards a slightly higher inbreeding and a lower number of breeders was observed in the declining population. Accordingly, we hypothesized that an increase in male gamete dispersal may buffer the increase of genetic drift expected in the declining population. This feedback between demographic decline and reproductive pattern may potentially take part in the long‐term persistence of red coral populations. However, the negative trend reported in the declining population unambiguously supports the need to maintain high densities of reproductive colonies to the functioning of red coral populations.

Nitrogen eutrophication particularly promotes turf algae in coral reefs of the central Red Sea.

While various sources increasingly release nutrients to the Red Sea, knowledge about their effects on benthic coral reef communities is scarce. Here, we provide the first comparative assessment of the response of all major benthic groups (hard and soft corals, turf algae and reef sands—together accounting for 80% of the benthic reef community) to in-situ eutrophication in a central Red Sea coral reef. For 8 weeks, dissolved inorganic nitrogen (DIN) concentrations were experimentally increased 3-fold above environmental background concentrations around natural benthic reef communities using a slow release fertilizer with 15% total nitrogen (N) content. We investigated which major functional groups took up the available N, and how this changed organic carbon (Corg) and N contents using elemental and stable isotope measurements. Findings revealed that hard corals (in their tissue), soft corals and turf algae incorporated fertilizer N as indicated by significant increases in δ15N by 8%, 27% and 28%, respectively. Among the investigated groups, Corg content significantly increased in sediments (+24%) and in turf algae (+33%). Altogether, this suggests that among the benthic organisms only turf algae were limited by N availability and thus benefited most from N addition. Thereby, based on higher Corg content, turf algae potentially gained competitive advantage over, for example, hard corals. Local management should, thus, particularly address DIN eutrophication by coastal development and consider the role of turf algae as potential bioindicator for eutrophication.

Observations of vulnerable marine ecosystems and significant adverse impacts on high seas seamounts of the northwestern Hawaiian Ridge and Emperor Seamount Chain

The Northwestern Hawaiian Ridge seamounts (NHR) outside the US EEZ and the Emperor Seamount Chain (ESC) have some of the longest history and largest takes of bottom contact fisheries of any seamounts globally. Imaging surveys from four of these seamounts provide evidence of vulnerable marine ecosystems (VMEs) on all surveyed features including dense patches of octocorals, scleractinian reefs, and sponges. Crinoids and brisingids occurred patchily in high abundance. These results, records from precious coral fishery takes, and habitat suitability modeling collectively indicate an extremely high probability that deep-sea coral VMEs are widespread on all of the ESC-NHR seamounts.Evidence for significant adverse impacts (SAIs) from bottom contact fisheries was also observed on all surveyed seamounts and included large areas of barren hard substrate, with scars from bottom contact gear in 19–29% of AUV images. Stumps from arborescent corals and rubble from reef-forming corals were observed. Evidence of SAIs is further supplied by many observations of coral rubble associated with lost fishing gear. Finally coralliid octocorals, once sufficiently abundant on the targeted seamounts to support the world's largest precious coral fishery, were extremely rare on all features despite the large survey area.Based on observations of VMEs, SAIs to these VMEs, and the potential for recovery, the results presented here would indicate a closure of all NHR and ESC seamounts to bottom contact fisheries until the gear being used can be proven to not cause SAIs. Closures should include both untrawled areas and currently fished areas to allow for recovery.

Morpho-molecular delineation of structurally important reef species, the fire corals, Millepora spp., at Réunion Island, Southwestern Indian Ocean

Looking at taxa that could dominate Anthropocene reefs, the fire corals, Millepora spp., represent compelling alternative because of their similar role than scleractinian corals. However, species identification has been the subject of much debate over the past 150 years. As they may turn as among the last refuges for reef biodiversity, it is critical to accurately delimit their species boundaries to appreciate better their resilience to future environmental conditions. Combining morphological and molecular approaches, we investigated Millepora species delimitation in Reunion Island where three species co-occur: Millepora exaesa, Millepora platyphylla and Millepora tenera. Our results showed that both pore characters and polyp morphologies successfully distinguished species. Gastropore and dactylopore numbers and diameters should be used as standard traits in Millepora. Regarding molecular delineation, the mitochondrial gene clearly segregated the species, whereas the nuclear gene showed shared haplotypes between species, likely influenced by ancestral polymorphism. Confirming the results of a recent study on Red Sea fire corals showing their distinction from the Indo-Pacific ones, we emphasize that formal re-descriptions of the Indo-Pacific M. cf. platyphylla and M. cf. exaesa are needed. Our study highlights the importance of a trait-based qualitative and quantitative approach coupled to molecular delineation, especially for structurally important reef species.

Red coral (Corallium rubrum) populations and coralligenous characterization within “Regno di Nettuno MPA” (Tyrrhenian Sea, Italy)

Red coral is one of the most important species belonging to the coralligenous habitats, being a structuring organism and highly sensitive to human pressure. The presence of red coral populations is historically well documented along the Campania coast (Tyrrhenian Sea), and, due to its high economic value, it has been commercially overharvested since ancient times. Red coral populations along several cliffs on the “Regno di Nettuno” MPA of the Gulf of Naples were investigated using ROV-imaging techniques. Coralligenous habitats were characterized in terms of percent cover and number of morphological groups. Pizzaco site showed the richest and most diverse community. Density of red coral colonies was calculated and compared with morphometric parameters. Results show an inversely correlated trend between colonies density and their size. Finally, fishing pressure was estimated through frequency of lost fishing gears, and S. Angelo site resulted the most stressed one. Anthropic stress plays a key role in the degradation of coralligenous habitats and the dramatic reduction of red coral populations recorded in recent years allows to suspect a more extensive degradation of the entire community. An assessment of the distribution and state of the populations can provide useful information to take measures for a better MPAs management.

Whole-genome sequencing of leopard coral grouper ( Plectropomus leopardus) and exploration of regulation mechanism of skin color and adaptive evolution.

Leopard coral groupers belong to the Plectropomus genus of the Epinephelidae family and are important fish for coral reef ecosystems and the marine aquaculture industry. To promote future research of this species, a high-quality chromosome-level genome was assembled using PacBio sequencing and Hi-C technology. A 787.06 Mb genome was assembled, with 99.7% (784.57 Mb) of bases anchored to 24 chromosomes. The leopard coral grouper genome size was smaller than that of other groupers, which may be related to its ancient status among grouper species. A total of 22 317 protein-coding genes were predicted. This high-quality genome of the leopard coral grouper is the first genomic resource for Plectropomus and should provide a pivotal genetic foundation for further research. Phylogenetic analysis of the leopard coral grouper and 12 other fish species showed that this fish is closely related to the brown-marbled grouper. Expanded genes in the leopard coral grouper genome were mainly associated with immune response and movement ability, which may be related to the adaptive evolution of this species to its habitat. In addition, we also identified differentially expressed genes (DEGs) associated with carotenoid metabolism between red and brown-colored leopard coral groupers. These genes may play roles in skin color decision by regulating carotenoid content in these groupers.

Historical record of Corallium rubrum and its changing carbon sequestration capacity: A meta-analysis from the North Western Mediterranean.

There is a scarcity of long time-span and geographically wide research on the health status of Corallium rubrum, including limited research on its historical ecology and carbon sequestration capacity. To reconstruct the temporal trends of the most reported C. rubrum population parameters in the Northwestern Mediterranean Sea and to determine the changes in total carbon sequestration by this species. Quantitative and qualitative, academic and grey documents were collected from scientific web browsers, scientific libraries, and requests to scientists. Documents with original information of basal diameter, height and/or weight per colony, with a depth limit of 60 m in the Catalan and Ligurian Seas were analyzed. We calculated yearly average values of C. rubrum biometric parameters, as well as estimated total weight, carbon flux, and carbon fixation in the structures of C. rubrum's colonies. In both study areas, the values of the selected morphometric parameters for C. rubrum decreased until the 1990s, then increased from the 2000s, with average values surpassing the levels of the 1960s (Ligurian Sea) or reaching levels slightly lower than those of the 1980s (Catalan Sea). The difference in carbon sequestered between the oldest (1960s: Ligurian Sea; 1970s: Catalan Sea) and the lowest (1990s) biomass value of colonies is nearly double. Quantitative data previous to the 1990s are very limited. Information on recent recovery trends in C. rubrum parameters is concentrated in a few areas and biased towards colonies in marine protected areas, with scarce quantitative information from colonies in other areas. The halt in the C. rubrum decreasing trend coincided with the exhaustion of tree-like colonies and the first recovery response due to effective protection measures in some areas. Nevertheless, C. rubrum climate change mitigation capacity through carbon sequestration can be drastically reduced from its potential in only a few decades.

Denitrification Aligns with N2 Fixation in Red Sea Corals

Denitrification may potentially alleviate excess nitrogen (N) availability in coral holobionts to maintain a favourable N to phosphorous ratio in the coral tissue. However, little is known about the abundance and activity of denitrifiers in the coral holobiont. The present study used the nirS marker gene as a proxy for denitrification potential along with measurements of denitrification rates in a comparative coral taxonomic framework from the Red Sea: Acropora hemprichii, Millepora dichotoma, and Pleuractis granulosa. Relative nirS gene copy numbers associated with the tissues of these common corals were assessed and compared with denitrification rates on the holobiont level. In addition, dinitrogen (N2) fixation rates, Symbiodiniaceae cell density, and oxygen evolution were assessed to provide an environmental context for denitrification. We found that relative abundances of the nirS gene were 16- and 17-fold higher in A. hemprichii compared to M. dichotoma and P. granulosa, respectively. In concordance, highest denitrification rates were measured in A. hemprichii, followed by M. dichotoma and P. granulosa. Denitrification rates were positively correlated with N2 fixation rates and Symbiodiniaceae cell densities. Our results suggest that denitrification may counterbalance the N input from N2 fixation in the coral holobiont, and we hypothesize that these processes may be limited by photosynthates released by the Symbiodiniaceae.

Productivity and carbon fluxes depend on species and symbiont density in soft coral symbioses

Soft corals often constitute one of the major benthic groups of coral reefs. Although they have been documented to outcompete reef-building corals following environmental disturbances, their physiological performance and thus their functional importance in reefs are still poorly understood. In particular, the acclimatization to depth of soft corals harboring dinoflagellate symbionts and the metabolic interactions between these two partners have received little attention. We performed stable isotope tracer experiments on two soft coral species (Litophyton sp. and Rhytisma fulvum fulvum) from shallow and upper mesophotic Red Sea coral reefs to quantify the acquisition and allocation of autotrophic carbon within the symbiotic association. Carbon acquisition and respiration measurements distinguish Litophyton sp. as mainly autotrophic and Rhytisma fulvum fulvum as rather heterotrophic species. In both species, carbon acquisition was constant at the two investigated depths. This is a major difference from scleractinian corals, whose carbon acquisition decreases with depth. In addition, carbon acquisition and photosynthate translocation to the host decreased with an increase in symbiont density, suggesting that nutrient provision to octocoral symbionts can quickly become a limiting factor of their productivity. These findings improve our understanding of the biology of soft corals at the organism-scale and further highlight the need to investigate how their nutrition will be affected under changing environmental conditions.

Marine Protected Areas in Peninsular Malaysia: Shifting from Political Process to Co-Management

Since fishing is a primary source of income to the coastal communities, conservation of marine natural resources is crucial to safeguard its sustainable supply. Therefore, intensive measures should be taken by all the stakeholders – from the authorities to the local fishermen. The precious coral reefs should be protected as important breeding habitat of various commercially valued species of marine resources and. Thus, in carrying out the political process of designating marine protected areas (MPAs) as marine parks, the local communities must also be engaged by the government due to their proximity to and dependency on the environment as direct resources users. Co-management or collaborative management by engaging the local communities, or community-based management, is the concept that could be able to remedy ineffective MPAs management in Peninsular Malaysia. Co-management or collaborative management approach between the authorities and the communities must be strategised by factoring in their local knowledge of living within and off the marine environment and resources. This study utilises content analysis method on the primary data, namely the national policies, federal acts, and state enactments. While the secondary data in form of official reports, scholarly articles and others deemed relevant are used to supplement and support the findings. This paper dwells on the possibility of shifting the process of MPAs designation from political process to co-management in Peninsular Malaysia, in order to achieve both environmental stability and the livelihood sustainability of the local communities.

Phenotypic Plasticity or a Reproductive Dead End? Primnoa pacifica (Cnidaria: Alcyonacea) in the Southeastern Alaska Region

Red tree corals (Primnoa pacifica) are abundant in the eastern Gulf of Alaska, from the glacial fjords of Southeast Alaska where they emerge to as shallow as 6 m, to the continental shelf edge and seamounts where they are more commonly found at depths greater than 150 m. This keystone species forms large thickets, creating habitat for many associated species, including economically valuable fishes and crabs, and so are important benthic suspension feeders in this region. Though the reproductive periodicity over 1.5 year period was reported in 2014 from a shallow fjord (Tracy Arm), this study examined reproductive ecologies from 8 sites – two within Glacier Bay National Park and Preserve, three on the continental shelf edge, one within Endicott Arm (Holkham Bay) and two time points from the Tracy Arm (Holkham Bay) study. Male reproductive traits were similar at all sites but there were distinct differences in oogenesis. Though fecundity mostly showed no significant difference between sites, there was a trend of increasing number of eggs with depth. Indeed, the average oocyte sizes from Tracy Arm (the shallowest site) was 105 m, whereas from Shutter Ridge (one of the deepest sites) the average size was 309 m. Moreover, the maximum oocyte size at Tracy Arm was 802 m, whereas it was 2120 m at Dixon Entrance, an almost 3-fold difference, and one not usually observed within a single species. We propose two theories to explain the observed differences, a) this species shows great phenotypic plasticity in reproductive ecology, adjusting to different environmental variables based on energetic need and potentially demonstrating micro-evolution; or b) the fjord sites are at a reproductive dead end, with the stress of shallow water conditions effectively preventing gametogenesis reaching full potential and likely limiting successful reproductive events from occurring, at least on a regular basis.

Physical connectivity simulations reveal dynamic linkages between coral reefs in the southern Red Sea and the Indian Ocean

The southern Red Sea is genetically distinct from the rest of the basin; yet the reasons responsible for this genetic separation remain unclear. Connectivity is a vital process for the exchange of individuals and genes among geographically separated populations, and is necessary for maintaining biodiversity and resilience in coral reef ecosystems. Here, using long-term, high-resolution, 3-D backward particle tracking simulations, we investigate the physical connectivity of coral reefs in the southern Red Sea with neighbouring regions. Overall, the simulation results reveal that the southern Red Sea coral reefs are more physically connected with regions in the Indian Ocean (e.g., the Gulf of Aden) than with the northern part of the basin. The identified connectivity exhibits a distinct monsoon-related seasonality. Though beyond the country boundaries, relatively remote regions of the Indian Ocean may have a substantial impact on the southern Red Sea coral reef regions, and this should be taken into consideration when establishing conservation strategies for these vulnerable biodiversity hot-spots.

Tribological Investigation of HDPE-cuttlebone and HDPE-red Coral Composites

In this paper, the tribological properties of cuttlebone (CB)-reinforced high density polyethylene (HDPE) and Red Coral (RC)-reinforced HDPE composites were investigated. The composite specimens were prepared with a hot compression molding machine using different weight proportions of fillers blended with HDPE. The tribological behavior of the composite disks was studied using pin-on-disk tribometer under dry condition against stainless steel M30NW pins. The coefficient of friction as well as wear rate were examined to study the effects of the two fillers on the tribological performance of both composites. After wear tests, different composites were examined using a Scanning Electron Microscope (SEM). It was found that the use of cuttlebone (CB) and Red Coral (RC) as reinforcement improved the tribological properties of HDPE.

Multiplexed ISSR genotyping by sequencing distinguishes two precious coral species (Anthozoa: Octocorallia: Coralliidae) that share a mitochondrial haplotype.

BackgroundPrecious corals known as coralliid corals (Anthozoa: Octocorallia) play an important role in increasing the biodiversity of the deep sea. Currently, these corals are highly threatened because of overfishing that has been brought on by an increased demand and elevated prices for them.The deep sea precious corals Pleurocorallium elatius and P. konojoi are distributed in Japanese waters and have distinct morphological features: (1) the terminal branches of the colony form of P. elatius are very fine, while those of P. konojoi are blunt and rounded, (2) the autozooids of P. elatius are arranged in approximately four rows, while those of P. konojoi are clustered in groups. However, previous genetic analysis using mtDNA and nuclear DNA did not indicate monophyly. Therefore, it is important to clarify their species status to allow for their conservation.MethodologyWe collected a total of 87 samples (60 of Corallium japonicum and 27 of P. konojoi) from around the Ryukyu Islands and Shikoku Island, which are geographically separated by approximately 1,300 km. We used a multiplexed inter-simple sequence repeat (ISSR) genotyping by sequencing (MIG-seq) and obtained 223 SNPs with which to perform STRUCTURE analysis and principle coordinate analysis (PCoA). In addition, two relatively polymorphic mtDNA regions were sequenced and compared.ResultsP. elatius and P. konojoi share a same mtDNA haplotype, which has been previously reported. However, MIG-seq analysis clearly distinguished the two species based on PCoA and STRUCTURE analysis, including 5% of species-specific fixed SNPs.ConclusionThis study indicated that P. elatius and P. konojoi are different species and therefore both species should be conserved separately. Our findings highlight the importance of the conservation of these two species, especially P. elatius, whose population has been dramatically depleted over the last 100 years. The study also demonstrated the effectiveness and robustness of MIG-seq for defining closely related octocoral species that were otherwise indistinguishable using traditional genetic markers (mtDNA and EF).

Feeding increases the number of offspring but decreases parental investment of Red Sea coral Stylophora pistillata.

Successful reproductive output and recruitment is crucial to coral persistence and recovery following anthropogenic stress. Feeding is known to alter coral physiology and increase resilience to bleaching.The goal of the study was to address the knowledge gap of the influence of feeding on reproductive output and offspring phenotype.Colonies of Stylophora pistillata from the Northern Gulf of Aqaba (Red Sea) were fed an Artemia diet or unfed for 5 months during gametogenesis, fertilization, and brooding. In addition, time to settlement and mortality of planulae were assessed at water temperatures ranging from winter temperature (22°C) to three degrees above average peak summer temperature (31°C). A range of physiological parameters was measured in parents and offspring.In brooding parents, feeding significantly increased protein concentration and more than tripled the number of released planulae. Planulae from unfed colonies had higher chlorophyll per symbiont concentration and concomitantly higher photosynthetic efficiency compared to planulae from fed parents. In settlement assays, planulae showed a similar thermal resistance as known for this Red Sea adult population. Mortality was greater in planulae from unfed parents at ambient and 3°C above ambient temperature despite higher per offspring investment in terms of total fatty acid content. Fatty acid profiles and relative abundances were generally conserved between different fed and unfed colonies but planulae were enriched in monounsaturated fatty acids relative to adults, that is, 16:1, 18:1, 20:1, 22:1, and 24:1 isomers.Ultimately the availability of zooplankton could influence population physiology and recruitment in corals.

Adhesion to coral surface as a potential sink for marine microplastics

Only 1% of plastic entering the ocean is found floating on its surface, with high loads in ocean accumulation zones and semi-enclosed seas, except for the Red Sea, which supports one of the lowest floating plastic loads worldwide. Given the extension of reefs in the Red Sea, we hypothesize a major role of scleractinian corals as sinks, through suspension-feeding, and assessed microplastic removal rates by three Red Sea coral species. Experimental evidence showed removal rates ranging from 0.25 × 10−3 to 14.8 × 10−3 microplastic particles polyp−1 hour−1, among species. However, this was only 2.2 ± 0.6% of the total removal rate, with passive removal through adhesion to the coral surface being 40 times higher than active removal through suspension-feeding. These results point at adhesion of plastic to coral reef structures as a major sink for microplastics suspended in the water column after sinking, helping explain low concentrations in Red Sea surface waters.

Coral forests and Derelict Fishing Gears in submarine canyon systems of the Ligurian Sea

Biodiversity of coral forests and occurrence of Derelict Fishing Gears (DFGs) have been assessed in canyon systems of the western Ligurian Sea (Dramont, Monaco, Bordighera, Arma di Taggia and Bergeggi) exposed to different anthropic pressures. Arborescent cnidarians were elected as representative species due to their role as structuring organisms and their vulnerability to DFGs damage; hence, their occurrence, density and distribution were correlated to the presence of DFGs. The canyon systems were mapped using a Multibeam Echo Sounder and visually surveyed by means of a Remotely Operated Vehicle between 20 and 445 m depth. With the exception of the Bergeggi canyon system, all sites host rich assemblages of structuring anthozoans, accounting for more than 2000 colonies belonging to 11 species, predominantly Eunicella cavolinii, Paramuricea clavata, Corallium rubrum, Dendrophyllia cornigera, and E. verrucosa. We noticed that the large structuring gorgonians were affected most, with a high number of entangled colonies.DFGs represent 85% of the marine litter found, and are the most serious threat to resident sessile communities, most noticeably in the eastern canyons. Ports, size and fishing effort of local fleets, and socio-economical differences in the fishing activities, strongly influence the fishing footprints.Our study further confirms the role of submarine canyons as site of high coral biodiversity and vulnerability to the mechanical damages by fishing-related littering, calling for adequate management measures to reduce fishery pressure and concomitant DFGs discharge.