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This study presents a novel approach to high-resolution density distribution mapping of two key species of the 1170 "Reefs" habitat, Dendrophyllia cornigera and Phakellia ventilabrum, in the Bay of Biscay using deep learning models. The main objective of this study was to establish a pipeline based on deep learning models to extract species density data from raw images obtained by a remotely operated towed vehicle (ROTV). Different object detection models were evaluated and compared in various shelf zones at the head of submarine canyon systems using metrics such as precision, recall, and F1 score. The best-performing model, YOLOv8, was selected for generating density maps of the two species at a high spatial resolution. The study also generated synthetic images to augment the training data and assess the generalization capacity of the models. The proposed approach provides a cost-effective and non-invasive method for monitoring and assessing the status of these important reef-building species and their habitats. The results have important implications for the management and protection of the 1170 habitat in Spain and other marine ecosystems worldwide. These results highlight the potential of deep learning to improve efficiency and accuracy in monitoring vulnerable marine ecosystems, allowing informed decisions to be made that can have a positive impact on marine conservation. [ABSTRACT FROM AUTHOR]

This study presents a novel approach to high-resolution density distribution mapping of two key species of the 1170 “Reefs” habitat, Dendrophyllia cornigera and Phakellia ventilabrum, in the Bay of Biscay using deep learning models. The main objective of this study was to establish a pipeline based on deep learning models to extract species density data from raw images obtained by a remotely operated towed vehicle (ROTV). Different object detection models were evaluated and compared in various shelf zones at the head of submarine canyon systems using metrics such as precision, recall, and F1 score. The best-performing model, YOLOv8, was selected for generating density maps of the two species at a high spatial resolution. The study also generated synthetic images to augment the training data and assess the generalization capacity of the models. The proposed approach provides a cost-effective and non-invasive method for monitoring and assessing the status of these important reef-building species and their habitats. The results have important implications for the management and protection of the 1170 habitat in Spain and other marine ecosystems worldwide. These results highlight the potential of deep learning to improve efficiency and accuracy in monitoring vulnerable marine ecosystems, allowing informed decisions to be made that can have a positive impact on marine conservation.

Molluscs of Chella Bank and its surroundings were studied from 21 samples collected with a van Veen grab in the depth range 95-729 m. A total of 299 taxa were identified (77 live-taken), thus increasing by more than 95% the species of molluscs reported in the recently declared site of community importance “Sur de Almería-Seco de los Olivos”. Two of the species are new records to Spanish waters and one to the Alboran Sea. The high species richness observed could be related to the location, the hydrological characteristics and the topographical heterogeneity of the area within the Alboran Sea. Four significant groups of samples were discriminated through multivariate analysis of quantitative data of live-taken molluscs: (I) bathyal muddy bottoms with buried rhodoliths; (II) bathyal muddy bottoms with coral rubble; (III) bathyal hemipelagic muddy bottoms and (IV) bathyal sandy bottoms. Molluscs were more diverse on coral framework bottoms than on sedimentary bottoms around Chella Bank. Most of the live-taken species are widely distributed along the Atlantic and Mediterranean Sea, and a few are strictly Mediterranean. The most striking feature was the occurrence of two species with planktotrophic larval development for which Chella Bank is the sole recorded locality in the Mediterranean (Episcomitra angelesae and Mitrella templadoi) and which elsewhere extremely rare (Mathilda spp.).

• Ensemble modeling predicts a broad distribution of L. phalangium in the western and central Mediterranean in the present day. • L. phalangium seems to be favoured in deep environments along the continental slope (100-500 m depth). • Predictions based on the IPCC scenarios RCP2.6 and RCP8.5 estimate a 50% to 70% reduction in its current suitable habitat. • Climate refugia were identified in the northern Mediterranean basin and must be considered as priority areas of conservation. Crinoid beds of Leptometra phalangium (Müller, 1841) have been identified as sensitive habitats by the General Fisheries Commission for the Mediterranean (GFCM) due to their high vulnerability to bottom trawl fisheries. Poorly resilient to physical damage, L. phalangium has been listed as a potential indicator of Vulnerable Marine Ecosystems (VMEs) in the Mediterranean Sea. If fishing activities represent the main cause of habitat destruction for this species, the ongoing changes in climate conditions may rapidly exacerbate the process. In this study, we developed an ensemble Species Distribution Modeling framework to predict the potential habitat of L. phalangium for present-days in the Mediterranean Sea, and used the model to infer potential changes in its spatial distribution by 2050 under two different climate scenarios (IPCC Representative Concentration Pathways RCP2.6 and RCP8.5). True presence-absence records were used and correlated to a parsimonious set of environmental predictors considered as important drivers of benthic species distribution. In present conditions, L. phalangium seems to be widely distributed along the continental slopes of the western and central Mediterranean. This crinoid is often described as confined to the continental shelf-break (100–200 m), but our results show that it can be found over a wider depth range, between 100 and 500 m. Our predictions obtained for the mid-21st century indicate an important habitat loss for L. phalangium under future climate conditions, mainly in the central and southern basins. Declines of 50 to 70 % in its suitable habitat were predicted under RCP2.6 and RCP8.5 compared to present-day predictions. Climate refugia (i.e., areas where environmental conditions remain suitable for the species in the future) were restricted to the northwestern basin (e.g., Gulf of Lion, the Catalan Sea, the Balearic Sea, Ligurian Sea) and in the southern Adriatic Sea. Provided by a robust statistical framework, climate refugia predictions, along with uncertainty assessments, must support the identification of priority areas for the conservation of VME indicator species by governmental bodies and regional management organizations. [ABSTRACT FROM AUTHOR]

The bamboo coral Isidella elongata is a forest-forming alcyonacean that dwells on deep-sea soft bottoms and is presently found in the Otranto Channel (Southern Adriatic Sea). In this study, we explored the spatial distribution and the demographic structure of the I. elongata facies (IF) over time, along with the diversity of IF-associated fauna in the southern Adriatic Sea, by using a time-series data of 9 years (2012–2020) from the Mediterranean International Bottom Trawl Survey (MEDITS). The spatial distribution of I. elongata was confronted with the fishing effort in the study area over time. This facies showed a constant spatial extent but a decreasing biomass over time. Changes in the basal diameter distribution of the colonies were also observed, with a significant decrease in the sizes from 2014 to 2020. These results suggest an increasing fishery-related impact from a developing deep-sea fishery occurring in the study area. The bamboo coral in the study area represents a hotspot of biodiversity in the context of the bathyal environment. A fisheries-restricted area was recently proposed in the context of the General Fisheries Commission for the Mediterranean at the Otranto Channel to help the conservation of I. elongata in the southern Adriatic Sea. [ABSTRACT FROM AUTHOR]

Abstract Mid‐ocean ridges generate a myriad of physical oceanographic processes that favor the supply of food and nutrients to suspension‐ and filter‐feeding organisms, such as cold‐water corals and deep‐sea sponges. However, the pioneering work conducted along the Mid‐Atlantic Ridge failed to report the presence of large and dense living coral reefs, coral gardens, or sponge aggregations. Here, we describe the densest, near‐natural, and novel octocoral garden composed of large red and white colonies of Paragorgia johnsoni Gray, 1862 discovered at 545–595 m depth on the slopes of the Mid‐Atlantic Ridge, in the Azores region. This newly discovered octocoral garden is a good candidate for protection since it fits many of the FAO criteria that define what constitutes a Vulnerable Marine Ecosystem. The observations described here corroborate the existence of a close relationship between the octocoral structure and the ambient currents on ridge‐like topographies, providing new insights into the functioning of mid‐ocean ridges' ecosystems. The ubiquitous presence of biogenic and geological topographies associated with mid‐ocean ridges, which could act as climate refugia, suggests their global importance for deep‐sea biodiversity. A better understanding of the processes involved is, therefore, required. Our observations may inspire future deep‐sea research initiatives to narrow existing knowledge gaps of biophysical connections with benthic fauna at small spatial scales along mid‐ocean ridges.

As part of the "Innovations in the Food System: Exploring the Future of Food" Special Issue, this paper briefly reviews studies that highlight a link between deep-sea fishery resources (deep-sea food resources) and vulnerable marine ecosystems (VME), species, and habitats in the Mediterranean Sea, providing new insights into changes in commercial and experimental catches of the deep-sea fishery resources in the central Mediterranean over the last 30 years. About 40% of the total landing of Mediterranean deep-water species is caught in the central basin. Significant changes in the abundance of some of these resources with time, sea-bottom temperature (SBT), and fishing effort (FE) have been detected, as well as an effect of the Santa Maria di Leuca cold-water coral province on the abundance of the deep-sea commercial crustaceans and fishes. The implications of these findings and the presence of several geomorphological features, sensitive habitats, and VMEs in the central Mediterranean are discussed with respect to the objectives of biodiversity conservation combined with those of management of fishery resources. [ABSTRACT FROM AUTHOR]

In this work, we integrate five case studies harboring vulnerable deep-sea benthic habitats in different geological settings from mid latitude NE Atlantic Ocean (24–42° N). Data and images of specific deep-sea habitats were acquired with Remoted Operated Vehicle (ROV) sensors (temperature, salinity, potential density, O2, CO2, and CH4). Besides documenting some key vulnerable deep-sea habitats, this study shows that the distribution of some deep-sea coral aggregations (including scleractinians, gorgonians, and antipatharians), deep-sea sponge aggregations and other deep-sea habitats are influenced by water masses’ properties. Our data support that the distribution of scleractinian reefs and aggregations of other deep-sea corals, from subtropical to north Atlantic could be dependent of the latitudinal extents of the Antarctic Intermediate Waters (AAIW) and the Mediterranean Outflow Waters (MOW). Otherwise, the distribution of some vulnerable deep-sea habitats is influenced, at the local scale, by active hydrocarbon seeps (Gulf of Cádiz) and hydrothermal vents (El Hierro, Canary Island). The co-occurrence of deep-sea corals and chemosynthesis-based communities has been identified in methane seeps of the Gulf of Cádiz. Extensive beds of living deep-sea mussels (Bathymodiolus mauritanicus) and other chemosymbiotic bivalves occur closely to deep-sea coral aggregations (e.g., gorgonians, black corals) that colonize methane-derived authigenic carbonates.

I horridus i on dead compared to partly dead coral, and on sponges vs. live coral vs. coral fragments. Keywords: cold-water corals; Dermechinus horridus; echinoid; ecosystem state shifts; Isididae; longline fishing; octocoral; polyp bailout; resilience; vulnerable marine ecosystem EN cold-water corals Dermechinus horridus echinoid ecosystem state shifts Isididae longline fishing octocoral polyp bailout resilience vulnerable marine ecosystem 1 5 5 02/03/22 20220201 NES 220201 The ability of corals to detach their polyps (leaving behind a naked skeleton) in times of stress, allows polyps to escape from a local source of hostility (Sammarco 1982). In the process, the sea urchins may damage the polyps and stress the colony, which starts to release polyps (bailout) at the tip/base and locations near the sea urchin. Second, it may be a colony stress response to sea urchin perching on the coral branches, leading to polyp bailout. [Extracted from the article]

Mid‐ocean ridges generate a myriad of physical oceanographic processes that favor the supply of food and nutrients to suspension‐ and filter‐feeding organisms, such as cold‐water corals and deep‐sea sponges. However, the pioneering work conducted along the Mid‐Atlantic Ridge failed to report the presence of large and dense living coral reefs, coral gardens, or sponge aggregations. Here, we describe the densest, near‐natural, and novel octocoral garden composed of large red and white colonies of Paragorgia johnsoni Gray, 1862 discovered at 545–595 m depth on the slopes of the Mid‐Atlantic Ridge, in the Azores region. This newly discovered octocoral garden is a good candidate for protection since it fits many of the FAO criteria that define what constitutes a Vulnerable Marine Ecosystem. The observations described here corroborate the existence of a close relationship between the octocoral structure and the ambient currents on ridge‐like topographies, providing new insights into the functioning of mid‐ocean ridges' ecosystems. The ubiquitous presence of biogenic and geological topographies associated with mid‐ocean ridges, which could act as climate refugia, suggests their global importance for deep‐sea biodiversity. A better understanding of the processes involved is, therefore, required. Our observations may inspire future deep‐sea research initiatives to narrow existing knowledge gaps of biophysical connections with benthic fauna at small spatial scales along mid‐ocean ridges. [ABSTRACT FROM AUTHOR]

Sea pens are considered to be of conservation relevance according to multiple international legislations and agreements. Consequently, any information about their ecology and distribution should be of use to management decision makers. This study aims to provide such information about six taxa of sea pen in Norwegian waters [Funiculina quadrangularis (Pallas, 1766), Halipteris spp., Kophobelemnon stelliferum (Müller, 1776), Pennatulidae spp., Umbellula spp., and Virgulariidae spp.]. Data exploration techniques and ensembled species distribution modelling (SDM) are applied to video observations obtained by the MAREANO project between 2006 and 2020. Norway-based ecological profiles and predicted distributions are provided and discussed. External validations and uncertainty metrics highlight model weaknesses (overfitting, limited training/external observations) and consistencies relevant to marine management. Comparison to international literature further identifies globally relevant findings: (a) disparities in the environmental profile of F. quadrangularis suggest differing “realised niches” in different locations, potentially highlighting this taxon as particularly vulnerable to impact, (b) none of the six sea pen taxa were found to consistently co-occur, instead partially overlapping environmental profiles suggests that grouping taxa as “sea pens and burrowing megafauna” should be done with caution post-analyses only, (c) higher taxonomic level groupings, while sometimes necessary due to identification issues, result in poorer quality predictive models and may mask the occurrence of rarer species. Community-based groupings are therefore preferable due to confirmed shared ecological niches while greater value should be placed on accurate species ID to support management efforts.

The concept of “vulnerable marine ecosystem” (VME) was included in United Nations (UN) General Assembly Resolution 61/105 as part of an international effort to minimize the effects of seafloor fisheries on the high seas. However, defining a VME was left to be developed by technical guidance to the UN Food and Agricultural Organization. In that venue certain categories of organisms were deemed to be indicator species, suggesting that areas with those species would be considered VMEs with subsequent management measures implemented to conserve those ecosystem attributes. We note that on seamounts VME indicator species can be distributed widely, in dense clusters or sparsely. A dense cluster, for example, of scleractinian corals or sponges, is most often referred to as a VME, but we argue that any such dense cluster is not an ecosystem, rather it is a community, likely one of many that make up the ecosystem. Other communities on the seamount that are not part of that dense cluster could include many small species (some yet to be discovered) who are also part of the ecosystem because they are part of the web of interactions and flow of materials/energy on the seamount. We also suggest that a seamount ecosystem might extend over several or many seamounts in a biogeographic area. We conclude that the term “ecosystem” in the VME concept outlined by the United Nations needs to be re-evaluated from a classical ecological perspective leading to spatial management approaches that better address ecologically relevant space and time scales.

A standing data gap for management of high-seas seamounts of the Northwestern Hawaiian Ridge and Emperor Seamounts (ES-NHR) by the North Pacific Fisheries Commission is the footprint of fisheries activities on these seamounts. Using satellite AIS data and the algorithms of the publicly available Global Fishing Watch database, a spatial map of trawling in a 0.01-degree latitude by 0.01-degree longitude square grid was created to review the data available to map this footprint. From 2012 to 2018 much of the trawling effort for all countries focused on Koko, Yuryaku, Kammu, and Colahan Seamounts at depths between 400 m (summits) and the depth limit currently set by the North Pacific Fisheries Commission of 1500 m. Additional seamounts with fishing activity included Annei (North Koko), Kinmei, Jingu, and Suiko. The remaining ES-NHR seamount locations show no trawling in those years. Bottom contact fishing was predominately carried out by ships with flag states of Japan and Korea. To date there appears to be compliance with the recent small-scale closures on C–H seamount and Koko.An additional source of data comes from scientific Autonomous Underwater Vehicle (AUV) surveys in 2014 and 2015 from three of these seamounts, in which scars from bottom contact gear are readily visible. These cover a smaller spatial area and depth range than the satellite data, but indicate the full footprint is not encompassed by the satellite data, suggesting either the fishing footprint is not fully captured by the AIS approach or that the footprint has shifted through time. AUV surveys also provide data on areas where abundant megafauna occur, which can provide candidate starting points for VME management efforts and further closures, similar to ones already in effect in the ES-NHR. The combination of satellite and AUV data provide a finer-scale fisheries footprint for this region that can aid in management of these sites.

As part of the “Innovations in the Food System: Exploring the Future of Food” Special Issue, this paper briefly reviews studies that highlight a link between deep-sea fishery resources (deep-sea food resources) and vulnerable marine ecosystems (VME), species, and habitats in the Mediterranean Sea, providing new insights into changes in commercial and experimental catches of the deep-sea fishery resources in the central Mediterranean over the last 30 years. About 40% of the total landing of Mediterranean deep-water species is caught in the central basin. Significant changes in the abundance of some of these resources with time, sea-bottom temperature (SBT), and fishing effort (FE) have been detected, as well as an effect of the Santa Maria di Leuca cold-water coral province on the abundance of the deep-sea commercial crustaceans and fishes. The implications of these findings and the presence of several geomorphological features, sensitive habitats, and VMEs in the central Mediterranean are discussed with respect to the objectives of biodiversity conservation combined with those of management of fishery resources.

Habitat heterogeneity is important for maintaining high levels of benthic biodiversity. The Prince Gustav Channel, on the Eastern Antarctic Peninsula, is characterized by an array of habitat types, ranging from flat, mud-dominated sheltered bays to steep and rocky exposed slopes. The channel has undergone dramatic environmental changes in recent decades, with the southern end of the channel permanently covered by the Prince Gustav Ice Shelf until it completely collapsed in 1995. Until now the marine benthic fauna of the Prince Gustav Channel has remained unstudied. A shallow underwater camera system and Agassiz trawl were deployed at different locations across the channel to collect information on habitat type and heterogeneity, benthic community composition and macrofaunal biomass. The texture of the seafloor was found to have a significant influence on the benthos, with hard substrates supporting higher abundances and diversity. Suspension and filter feeding organisms, including porifera, crinoids, and anthozoans, were strongly associated with hard substrates, with the same being true for deposit feeders, such as holothurians, and soft sediments. Habitat heterogeneity was high across the Prince Gustav Channel, particularly on a local scale, and this was significant in determining patterns of benthic composition and abundance. Other physical variables including depth and seafloor gradient played significant, interactive roles in determining composition potentially mediated through other processes. Sites that were once covered by the Prince Gustav Ice Shelf held distinct and unique communities, suggesting that the legacy of the ice shelf collapse may still be reflected in the benthos. Biomass estimations suggest that critical thresholds of vulnerable marine ecosystem indicator taxa, as defined by the Commission for the Conservation of Antarctic Marine Living Resources, have been met at multiple locations within the Prince Gustav Channel, which has implications for the future establishment of no take zones and marine protected areas within the region.

Environmental harm to deep-sea coral reefs on seamounts is widely attributed to bottom trawl fishing. Yet, accurate diagnoses of impacts truly caused by trawling are surprisingly rare. Similarly, comprehensive regional assessments of fishing damage rarely exist, impeding evaluations of, and improvements to, conservation measures. Here we report on trawling impacts to deep-sea scleractinian coral reefs in a regional (10–100s of km) fishery seascape off Tasmania (Australia). Our study was based on 148 km of towed camera transects (95 transects on 51 different seamounts with 284,660 separate video annotations and 4,674 “on-seamount” images analysed), and commercial trawling logbook data indexing fishing effort on and around seamounts. We detect trawling damage on 88% (45 of 51) of seamounts. Conversely, intact deep-sea coral reefs persist in refuge areas on about 39% (20 of 51) of the seamounts, and extend onto rocky seabed adjacent to seamounts. Depth significantly shapes the severity of trawl damage. The most profound impacts are evident on shallow seamounts (those peaking in < 950 m depths) where recent and repeated trawling reduced reefs built by scleractinian corals to rubble, forming extensive accumulations around seamount peaks and flanks. At intermediate depths (∼950–1,500 m), trawling damage is highly variable on individual seamounts, ranging from substantial impacts to no detection of coral loss. Deep seamounts (summit depth > 1,500 m) are beyond the typical operating depth of the trawl fishery and exceed the depth range of living deep-sea coral reefs in the region. Accurately diagnosing the nature and extent of direct trawling impacts on seamount scleractinian coral reefs must use stringent criteria to guard against false positive identifications of trawl impact stemming from either (1) misidentifying areas that naturally lacked deep-sea coral reef as areas where coral had been removed, or (2) attributing trawling as the cause of natural processes of reef degradation. The existence of sizeable deep-sea coral reef refuges in a complex mosaic of spatially variable fishing effort suggests that more nuanced approaches to conservation may be warranted than simply protecting untrawled areas, especially when the biological resources with conservation value are rare in a broader seascape context.

The Mohn’s Treasure, described as an inactive sulfide mound, was discovered at 2,600-m depth on the Arctic Mid-Ocean Ridge (AMOR) in 2002. In 2015, we conducted the first biological survey of Mohn’s Treasure using remotely operated vehicle (ROV) photo transects and sampling. This site is covered by a thick layer of fine sediments, where hard substratum is only visible as rocky outcrops on ridges. The observed benthic community was typical of Arctic bathyal systems. A total of 46 species (identified as morphospecies) were recorded, with densities varying from 12.2 to 31.6 ind.m–2. The two most abundant phyla were Porifera and Echinodermata. The sediment is dominated by fields of the stalked crinoid Bathycrinus carpenterii, whereas areas of hard substratum were characterized by high abundances of several sponge species and associated fauna. Interest in commercial exploration and exploitation of minerals from massive sulfide deposits is rising globally, and the AMOR is being targeted for mineral exploration within Norwegian waters. Gathering baseline ecological data from these poorly known sites is thus urgent and essential if robust resource management measures are to be developed and implemented. The results of this ecological survey are discussed in relation to the designation of deep-sea vulnerable marine ecosystems (VMEs) and their implication in management and conservation of areas targeted by the emerging deep-sea mining industry.

Protection of vulnerable marine ecosystems (VME) is a critical goal for marine conservation. Yet, in many deep-sea settings, where quantitative data are typically sparse, it is challenging to correctly identify the location and size of VMEs. Here we assess the sensitivity of a method to identify coral reef VMEs based on bottom cover and abundance of the stony coral Solenosmilia variabilis on deep seamounts, using image data from a survey off Tasmania, Australia, in 2018. Whilst there was some detectable influence from varying coral cover and the abundance of live coral heads, the distribution of coral reef VMEs was not substantially shifted by changing these criteria or altering the attributes of a moving window used to spatially aggregate coral patches. Whilst applying stricter criteria for classifying VMEs predictably produced smaller areas of coral reef VME, these differences were not sizeable and were often negligible. Coral reef VMEs formed large contiguous “blankets,” mainly on the peaks and flanks of seamounts, but were absent from the continental slope where S. variabilis occurred at low abundance (cover) and/or had no living colonies. The true size of the Tasmanian coral reef VMEs ranged from 0.02 to 1.16 km2; this was relatively large compared to reefs of S. variabilis mapped on New Zealand seamounts, but is small compared to the scales used for regional model predictions of suitable habitat (typically 1 km2 grid cell), and much smaller than the smallest units of management interest (100s–1000s km2). A model prediction of the area of suitable habitat for coral reef in the Tasmanian area was much greater than the area of coral reef estimated in this study. That the method to estimate VME size is not overly sensitive to the choice of criteria is highly encouraging in the context of designing spatial conservation measures that are robust, although its broader application, including to other VME indicator taxa, needs to be substantiated by scenario testing in different environments. Importantly, these results should give confidence for stakeholder uptake and form the basis for better predictive VME models at larger spatial scales and beyond single taxa.

The United Nations General Assembly has called for the adoption of conservation management measures to protect vulnerable marine ecosystems (VMEs) from significant adverse impacts outside of areas of national jurisdiction. In response, many regional fisheries management organizations (RFMOs) have implemented move-on rules triggered by encounter threshold levels for the biomass of VME indicator taxa retained as bycatch. However, due to uncertainty of the relationships between catch, catch efficiency and the in situ biomass of VME indicator taxa, move-on rules alone may not be enough to prevent significant adverse impacts on VMEs. Although spatial management measures present one possible solution to these concerns, a lack of empirical data on the distribution of VMEs within the high seas means spatial management is often informed by model predictions of the spatial distribution of VME indicator taxa. Given the uncertainty associated with predicted distributions, move-on rules can provide immediate responses when spatial management measures may not be providing the expected conservation benefits. Using bycatch data from 9,771 New Zealand bottom trawls within the South Pacific RFMO Convention Area, we illustrate a data-informed approach for selecting high move-on encounter thresholds that may suggest the predicted distributions of VME taxa used to underpin spatial management are highly inaccurate. The reasoning that high thresholds act as a safeguard against uncertainty in the performance of spatial management measures requires untested assumptions regarding the level of permissible bycatch before further management action is required, with the acceptance of those assumptions a management decision balancing the sensitivity of the move-on rule with uncertainty regarding the effectives of the spatial management measures. Additional work is required to support these management decisions, including the determination of taxa-specific catchability estimates, and the seafloor density/biomass of VME indicator taxa that represents a VME. Obtaining this information will allow for the identification of encounter thresholds that are more ecologically meaningful. In the interim, the choice of thresholds should be re-evaluated as more experience with their application is gathered.

Addressing growing threats of overexploitation to the world’s oceans is especially challenging in the High Seas, where limited data and international jurisdiction make it difficult to determine where and when conservation measures are necessary. Of particular concern are vulnerable marine ecosystems (VMEs)—special habitats on the seafloor that are highly sensitive to disturbance and slow to recover. To ensure the long-term conservation and sustainable use of marine resources, regional fisheries management organizations are committed to identifying the locations of VMEs and responding to prevent significant adverse impacts (SAIs). For over 50 years, Cobb Seamount—a shallow underwater volcanic mountain in the Northeast Pacific Ocean—has been commercially fished by multiple nations using various types of gear. Here we have assimilated data from fisheries records and a recent visual survey on the seamount. Our findings show a variety of habitat-forming emergent biological structures widely distributed on Cobb Seamount and generally depth-stratified into high-density assemblages (≥1 m–2). Our spatial analyses show that fishing has also been widely distributed, overlapping the habitat of the biological structures. We found fewer cold-water corals, sponges, and other biological structures in areas with higher recent fishing effort and documented evidence of fishing impacts, such as extensive mats of coral rubble and a high abundance of derelict fishing gear entangled with dead or damaged organisms. Based on the average density of “lost” gear (2,785 ± 1,003 km–2), we can confidently estimate that hundreds of thousands of items of derelict fishing gear are currently entangled with the seafloor of Cobb Seamount and that these pose an ongoing threat to biological structures, the biogenic habitats they create, and the species they support. Such impacts can persist for decades or centuries to come. This study contributes and discusses new information on the condition and distribution of biological structures, VME indicator taxa, physically complex biogenic ecosystems, and human impacts on Cobb Seamount. These data will be necessary to identify the location(s) of potential VMEs and SAIs on this heavily fished seamount in the High Seas.

Habitat suitability models are being used worldwide to help map and manage marine areas of conservation importance and scientific interest. With groundtruthing, these models may be found to successfully predict patches of occurrence, but whether all patches are part of a larger interbreeding metapopulation is much harder to assert. Here we use a North Atlantic deep-sea case study to demonstrate how dispersal models may help to complete the picture. Pheronema carpenteri is a deep-sea sponge that, in aggregation, forms a vulnerable marine ecosystem in the Atlantic Ocean. Published predictive distribution models from United Kingdom and Irish waters have now gained some support from targeted groundtruthing, but known aggregations are distantly fragmented with little predicted habitat available in-between. Dispersal models were used to provide spatial predictions of the potential connectivity between these patches. As little is known of P. carpenteri’s reproductive methods, twenty-four model set-ups with different dispersal assumptions were simulated to present a large range of potential dispersal patterns. The results suggest that up to 53.1% of the total predicted habitat may be reachable in one generation of dispersal from known populations. Yet, even in the most dispersive scenario, the known populations in the North (Hatton-Rockall Basin) and the South (Porcupine Sea Bight) are predicted to be unconnected, resulting in the relative isolation of these patches across multiple generations. This has implications for Ireland’s future conservation efforts as they may have to conserve patches from more than one metapopulation. This means that conserving one patch may not demographically support the other, requiring additional attentions to ensure that marine protected areas are ecologically coherent and sustainable. This example serves as a demonstration of a combined modeling approach where the comparison between predicted distribution and dispersal maps can highlight areas with higher conservation needs.

Vulnerable marine ecosystems (VMEs) are considered hotspots of biodiversity and ecosystem functioning in the deep sea, but are also characterised by a high vulnerability to disturbance and a low recovery potential. Since 2006, a series of United Nations General Assembly (UNGA) resolutions have been developed, attempting to ensure the protection of VMEs in international waters. In the Northwest Atlantic Fisheries Organisation (NAFO) Regulatory Area, large areas of seabed have been closed to bottom-contact fishing to protect VMEs. However, knowledge of the influence of VME-indicator taxa on macrofaunal assemblages, and the appropriateness of current fishery closures for protecting macrofaunal biodiversity in this area is limited. Here we investigate relationships between the prevalence of VME-indicator taxa [poriferans (sponges), gorgonian corals, and pennatulaceans (sea pens)] and an extensive suite of peracarid crustacean biodiversity metrics in the NAFO Regulatory Area. We also examine whether the current NAFO VME closures protect areas of significantly elevated peracarid diversity. Of the VME-indicator taxa analysed, poriferans were found to have by far the greatest influence over peracarid assemblages. Assemblage structure was altered, and peracarid abundance, biomass, richness, diversity, and variability were enhanced in areas of elevated poriferan biomass, whilst assemblage evenness was slightly depressed in these areas. These findings reaffirm the perception of poriferans as crucial components of VMEs. In contrast, gorgonian coral density had little influence over the faunal assemblages investigated, perhaps reflecting their relatively low prevalence in the study area. Similarly, pennatulaceans were found to influence peracarid assemblages only weakly. This too may reflect a moderately low density of Pennatulacea in the study area. Our results highlight that the application of taxon distribution model outputs to ecological investigations and management decisions in data-limited environments should be treated with caution. Finally, our results indicate that the current system of fishery closures in the NAFO Regulatory Area may not be optimal in terms of providing adequate protection to VMEs against the impacts of bottom trawling.

Abstract The Northwest Atlantic Fisheries Organization (NAFO) Roadmap is the general framework aimed toward implementing an Ecosystem Approach to Fisheries (EAF) in NAFO. The core principles are: a) the approach has to be objective-driven, b) it should consider long-term ecosystem sustainability, c) it must be place-based, and d) the consequences of trade-offs in managing human activities have to be explicitly defined. The Roadmap is not a fixed plan; it evolves as different components are developed, refined, and implemented. Core elements of the Roadmap include the identification of ecosystem-based management units, a hierarchical approach to define exploitation rates by considering ecosystem, multispecies, and stock level sustainability, and the integration of impacts on benthic communities. The modular design of the plan has allowed NAFO to start implementing some components (e.g. closures to bottom fishing for the protection of Vulnerable Marine Ecosystems), while work on others is still ongoing (e.g. multispecies modelling). Even though the Roadmap is far from being fully implemented, NAFO has made important progress towards EAF over the last decade. This paper summarizes the Roadmap structure and the current level of implementation, describes some of the challenges faced, and examines those still ahead. [ABSTRACT FROM AUTHOR]

Con motivo de la creciente preocupación internacional por el manejo y conservación de ecosistemas marinos vulnerables, entre los que se cuentan los montes submarinos y los corales de aguas frías de las cordilleras de Nazca y Salas y Gómez, y en vista de la inminente creación de la Organización Regional de Administración Pesquera del Pacifico Sur, se hace necesaria una revisión de los principales antecedentes científicos sobre estas cadenas montañosas como un insumo para la toma de decisiones. El presente documento atiende dicha necesidad considerando los aspectos geológicos, oceanógraficos, biológicos, ecológicos y pesqueros asociados a Nazca y, Salas y Gómez, junto con identificar las opciones de manejo. A pesar que los estudios en el área son escasos y fragmentados, se destaca su particularidad debido a los altos niveles de ende-mismo, alta diversidad de especies, alta concentración de montes submarinos, presencia de corales de aguas frías, mayor nivel de productividad en relación a las aguas circundantes y su potencialidad para actividades de océano-minería y pesca de fondo. Debido a la lejanía del área y los altos costos involucrados, una mayor cooperación internacional se requerirá para abordar futuros estudios, al tiempo que la creación de una red de Á-reas Marinas Protegidas se identifica como la mejor opción para el manejo y conservación.Due to growing international awareness of the importance of the conservation and management of vulnerable marine ecosystems - of which the seamounts and deep-sea corals of the Nazca and Salas y Gómez submarine ridges are examples - and taking into account the imminent establishment of a South Pacific Regional Fisheries Management Organization, a scientific review of this seamount chain is needed to provide input for decision-making processes. This paper provides such a review, considering geological, oceanographic, biological, ecological, and fisheries issues associated with Nazca and Salas y Gómez, and also identifies some management options. Notwithstanding the limited and fragmented studies available, this distinctive area has a high level of endemism, rich biodiversity, seamount density, deep-sea corals, relatively elevated primary productivity (considering the surrounding waters), and the potential for bottom fisheries and ocean-mining activities. Because of the remoteness of the área and the high costs involved, strong international cooperation will be required to undertake future studies. A network of Marine Protected Áreas is identified as the best management option for the area.

Deep-water sponges are considered ecosystem engineers, and the presence of large aggregations of these organisms, commonly referred to as sponge grounds, is associated with enhanced biodiversity and abundance of epibenthic fauna compared to non-sponge habitat. However, the degree and magnitude to which the presence of these sponge grounds elicits large changes in composition of the associated megafaunal community remains unknown. Here we identify the external drivers of epibenthic megafaunal community composition and explore the patterns and magnitude of compositional change in the megafaunal community within the sponge grounds of the Sackville Spur, northwest Atlantic. Epibenthic megafauna were quantified from five image transects collected on the Sackville Spur in 2009 between 1080 and 1723 m depth. Using Gradient Forest Modelling we found that the abundance of structure-forming sponges was the most important variable for predicting compositional patterns in the Sackville Spur megafaunal community, followed by depth, range in bottom current speed, in situ salinity, and longitude. Along the gradient in structure-forming sponge abundance, the largest turnover in megafaunal community composition occurred when the sponges reached 15 individuals m −2 . Examination of the regional hydrographic conditions suggests that the dense sponge grounds of the Sackville Spur are associated with a warm, salty water mass that occurs between ~1300 and 1800 m. [ABSTRACT FROM AUTHOR]

Dense coral-sponge communities on the upper continental slope at 570-950m off George V Land, East Antarctica have been identified as Vulnerable Marine Ecosystems. The challenge is now to understandtheir probable distribution on other parts of the Antarctic margin. We propose three main factors governing their distribution on the George V margin: 1) their depth in relation to iceberg scouring, 2) the flow of organicrich bottom waters, and 3) their location at the head of shelf cutting canyons. Icebergs scour to 500m in this region and the lack of such disturbance is a probable factor allowing the growth of rich benthic ecosystems. In addition, the richest communities are found in the heads of canyons which receive descending plumes of Antarctic BottomWater formed on the George V shelf, which could entrain abundant food for the benthos. The canyons harbouring rich benthos are also those that cut the shelf break. Such canyons are known sites of high productivity in other areas due to strong current flow and increased mixing with shelf waters, and the abrupt, complex topography. These proposed mechanisms provide a framework for the identification of areas where there is a higher likelihood of encountering these Vulnerable Marine Ecosystems. [ABSTRACT FROM AUTHOR]

Due to growing international awareness of the importance of the conservation and management of vulnerable marine ecosystems - of which the seamounts and deep-sea corals of the Nazca and Salas y Gómez submarine ridges are examples - and taking into account the imminent establishment of a South Pacific Regional Fisheries Management Organization, a scientific review of this seamount chain is needed to provide input for decision-making processes. This paper provides such a review, considering geological, oceanographic, biological, ecological, and fisheries issues associated with Nazca and Salas y Gómez, and also identifies some management options. Notwithstanding the limited and fragmented studies available, this distinctive area has a high level of endemism, rich biodiversity, seamount density, deep-sea corals, relatively elevated primary productivity (considering the surrounding waters), and the potential for bottom fisheries and ocean-mining activities. Because of the remoteness of the area and the high costs involved, strong international cooperation will be required to undertake future studies. A network of Marine Protected Areas is identified as the best management option for the area. [ABSTRACT FROM AUTHOR]

Abstract: The ecosystem approach for fisheries management is a widely accepted concept and various international instruments require its application. However, there are various interpretations of the ecosystem approach and its application almost always brings about confrontations and resistance among managers, proponents, and stakeholders. This paper categorizes the ecosystem approach into four distinguishable types: bycatch mitigation, multi-species management, protection of vulnerable ecosystems, and integrated approach. Furthermore, the lack of identification and understanding of specific management goals is hampering the application of the ecosystem approach. Unless the stakeholders understand and accept the goals, the ecosystem approach will not succeed. [Copyright &y& Elsevier]

Gazul is the shallowest mud volcano (MV) within the Shallow Field of Fluid Expulsion (SFFE) of the northeastern Gulf of Cádiz (NE Atlantic; 300–1200 m depth). The SFFE represents an important geo- and biodiversity area that was designated as a Site of Community Importance under the European Habitats Directive in 2014. In this study, geological features, habitats and associated biodiversity, as well as anthropogenic impacts, were characterized at Gazul MV from underwater imagery and multibeam bathymetry. Multivariate methods using the Bray-Curtis similarity index identified six main habitats, each of which harbored a characteristic faunal assemblage that included: (1) sandy ripple bottoms typified by the actiniarian Actinauge richardi ; (2) sandy, muddy, coarse sand and bioclastic bottoms dominated by the solitary coral Flabellum chunii ; (3) coarse sand and bioclastic bottoms, together with soft sediments covered by scattered methane-derived authigenic carbonates (MDACs) (mixed bottoms), characterized by the echinoid Cidaris cidaris ; (4) hard bottoms comprising MDACs dominated by a wide variety of sponges and gorgonians; (5) coral-rubble bottoms typified by the presence of colonial scleractinian communities dominated by Madrepora oculata ; and (6) mixed bottoms characterized by the presence of a styelid ascidian. Slope and water depth were the main factors explaining assemblages' distribution, which was also supported by the presence of MDACs such as slabs, crusts and chimneys on the seafloor, as well as by the geomorphologic diversity of Gazul MV. The results highlight Gazul MV as an eco-biologically important area harboring different vulnerable marine ecosystem (VME) elements with indicator taxa such as scleractinians, sponges, gorgonians and black corals. ROV images revealed abandoned or lost fishing gears and marine debris on the seafloor, indicating anthropogenic impacts in Gazul MV and adjacent areas. Indeed trawling fisheries activities have also been detected in Vessel Monitoring System datasets. A fishery restricted area is recommended in Gazul MV due to the occurrence of diverse VMEs and species included in different conservation directives and conventions. • Gazul MV presents a high geomorphological variability and diversity of bottom types. • Six main epibenthic assemblages have been identified conforming habitats. • Hard bottoms of the MV edifice contain the most biodiverse assemblages. • Cold-water coral communities are dominated by Madrepora oculata. • Gazul MV harbors different vulnerable marine ecosystem elements and indicators. [ABSTRACT FROM AUTHOR]

• Remote sensing data is used to better define the bottom-contact fishing footprint. • Trawling is the main form of bottom-contact fishing currently focused on four main seamounts. • AUV data shows remnant coral and sponge populations along the edges of fishing footprints. • Coral and sponge locations where little fishing has occurred are optimal areas for VME protections. A standing data gap for management of high-seas seamounts of the Northwestern Hawaiian Ridge and Emperor Seamounts (ES-NHR) by the North Pacific Fisheries Commission is the footprint of fisheries activities on these seamounts. Using satellite AIS data and the algorithms of the publicly available Global Fishing Watch database, a spatial map of trawling in a 0.01-degree latitude by 0.01-degree longitude square grid was created to review the data available to map this footprint. From 2012 to 2018 much of the trawling effort for all countries focused on Koko, Yuryaku, Kammu, and Colahan Seamounts at depths between 400 m (summits) and the depth limit currently set by the North Pacific Fisheries Commission of 1500 m. Additional seamounts with fishing activity included Annei (North Koko), Kinmei, Jingu, and Suiko. The remaining ES-NHR seamount locations show no trawling in those years. Bottom contact fishing was predominately carried out by ships with flag states of Japan and Korea. To date there appears to be compliance with the recent small-scale closures on C–H seamount and Koko. An additional source of data comes from scientific Autonomous Underwater Vehicle (AUV) surveys in 2014 and 2015 from three of these seamounts, in which scars from bottom contact gear are readily visible. These cover a smaller spatial area and depth range than the satellite data, but indicate the full footprint is not encompassed by the satellite data, suggesting either the fishing footprint is not fully captured by the AIS approach or that the footprint has shifted through time. AUV surveys also provide data on areas where abundant megafauna occur, which can provide candidate starting points for VME management efforts and further closures, similar to ones already in effect in the ES-NHR. The combination of satellite and AUV data provide a finer-scale fisheries footprint for this region that can aid in management of these sites. [ABSTRACT FROM AUTHOR]