Detrimental effects of ocean acidification on the economically important Mediterranean red coral (Corallium rubrum)

The mean predicted decrease of 0.3-0.4 pH units in the global surface ocean by the end of the century has prompted urgent research to assess the potential effects of ocean acidification on the marine environment, with strong emphasis on calcifying organisms. Among them, the Mediterranean red coral (Corallium rubrum) is expected to be particularly susceptible to acidification effects, due to the elevated solubility of its Mg-calcite skeleton. This, together with the large overexploitation of this species, depicts a bleak future for this organism over the next decades. In this study, we evaluated the effects of low pH on the species from aquaria experiments. Several colonies of C. rubrum were long-term maintained for 314 days in aquaria at two different pH levels (8.10 and 7.81, pHT). Calcification rate, spicule morphology, major biochemical constituents (protein, carbohydrates and lipids) and fatty acids composition were measured periodically. Exposure to lower pH conditions caused a significant decrease in the skeletal growth rate in comparison with the control treatment. Similarly, the spicule morphology clearly differed between both treatments at the end of the experiment, with aberrant shapes being observed only under the acidified conditions. On the other hand, while total organic matter was significantly higher under low pH conditions, no significant differences were detected between treatments regarding total carbohydrate, lipid, protein and fatty acid composition. However, the lower variability found among samples maintained in acidified conditions relative to controls, suggests a possible effect of pH decrease on the metabolism of the colonies. Our results show, for the first time, evidence of detrimental ocean acidification effects on this valuable and endangered coral species

Diversity, structure and spatial distribution of megabenthic communities in Cap de Creus continental shelf and submarine canyon (NW Mediterranean)

The continental shelf and submarine canyon off Cap de Creus (NW Mediterranean) were declared a Site of Community Importance (SCI) within the Natura 2000 Network in 2014. Implementing an effective management plan to preserve its biological diversity and monitor its evolution through time requires a detailed character ization of its benthic ecosystem. Based on 60 underwater video transects performed between 2007 and 2013 (before the declaration of the SCI), we thoroughly describe the composition and structure of the main mega benthic communities dwelling from the shelf down to 400 m depth inside the submarine canyon. We then mapped the spatial distribution of the benthic communities using the Random Forest algorithm, which incor porated geomorphological and oceanographic layers as predictors, as well as the intensity of the bottom-trawling fishing fleet. Although the study area has historically been exposed to commercial fishing practices, it still holds a rich benthic ecosystem with over 165 different invertebrate (morpho)species of the megafauna identified in the video footage, which form up to 9 distinct megabenthic communities. The continental shelf is home to coral gardens of the sea fan Eunicella cavolini, sea pen and soft coral assemblages, dense beds of the crinoid Leptometra phalangium, diverse sponge grounds and massive aggregations of the brittle star Ophiothrix fragilis. The submarine canyon off Cap de Creus is characterized by a cold-water coral community dominated by the scleractinian coral Madrepora oculata, found in association with several invertebrate species including oysters, brachiopods and a variety of sponge species, as well as by a community dominated by cerianthids and sea urchins, mostly in sedimentary areas. The benthic communities identified in the area were then compared with habitats/biocenoses described in reference habitat classification systems that consider circalittoral and bathyal environments of the Mediterranean. The complex environmental setting characteristic of the marine area off Cap de Creus likely produces the optimal conditions for communities dominated by suspension- and filter-feeding species to develop. The uniqueness of this ecosystem and the anthropogenic pressures that it faces should prompt the development of effective management actions to ensure the long-term conservation of the benthic fauna representative of this marine area3,26

Climate change considerations are fundamental to management of deep‐sea resource extraction

Climate change manifestation in the ocean, through warming, oxygen loss, increasing acidification, and changing particulate organic carbon flux (one metric of altered food supply), is projected to affect most deep‐ocean ecosystems concomitantly with increasing direct human disturbance. Climate drivers will alter deep‐sea biodiversity and associated ecosystem services, and may interact with disturbance from resource extraction activities or even climate geoengineering. We suggest that to ensure the effective management of increasing use of the deep ocean (e.g., for bottom fishing, oil and gas extraction, and deep‐seabed mining), environmental management and developing regulations must consider climate change. Strategic planning, impact assessment and monitoring, spatial management, application of the precautionary approach, and full‐cost accounting of extraction activities should embrace climate consciousness. Coupled climate and biological modeling approaches applied in the water and on the seafloor can help accomplish this goal. For example, Earth‐System Model projections of climate‐change parameters at the seafloor reveal heterogeneity in projected climate hazard and time of emergence (beyond natural variability) in regions targeted for deep‐seabed mining. Models that combine climate‐induced changes in ocean circulation with particle tracking predict altered transport of early life stages (larvae) under climate change. Habitat suitability models can help assess the consequences of altered larval dispersal, predict climate refugia, and identify vulnerable regions for multiple species under climate change. Engaging the deep observing community can support the necessary data provisioning to mainstream climate into the development of environmental management plans. To illustrate this approach, we focus on deep‐seabed mining and the International Seabed Authority, whose mandates include regulation of all mineral‐related activities in international waters and protecting the marine environment from the harmful effects of mining. However, achieving deep‐ocean sustainability under the UN Sustainable Development Goals will require integration of climate consideration across all policy sectors.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2020 The Authors. Global Change Biology published by John Wiley & Sons Lt

Report on the Marine Imaging Workshop 2017

Marine optical imaging has become a major assessment tool in science, policy and public understanding of our seas and oceans. Methodology in this field is developing rapidly, including hardware, software and the ways of their application. The aim of the Marine Imaging Workshop (MIW) is to bring together academics, research scientists and engineers, as well as industrial partners to discuss these developments, along with applications, challenges and future directions. The first MIW was held in Southampton, UK in April 2014. The second MIW, held in Kiel, Germany, in 2017 involved more than 100 attendees, who shared the latest developments in marine imaging through a combination of traditional oral and poster presentations, interactive sessions and focused discussion sessions. This article summarises the topics addressed during the workshop, particularly the outcomes of these discussion sessions for future reference and to make the workshop results available to the open public

A framework for the development of a global standardised marine taxon reference image database (SMarTaR-ID) to support image-based analyses

Video and image data are regularly used in the field of benthic ecology to document biodiversity. However, their use is subject to a number of challenges, principally the identification of taxa within the images without associated physical specimens. The challenge of applying traditional taxonomic keys to the identification of fauna from images has led to the development of personal, group, or institution level reference image catalogues of operational taxonomic units (OTUs) or morphospecies. Lack of standardisation among these reference catalogues has led to problems with observer bias and the inability to combine datasets across studies. In addition, lack of a common reference standard is stifling efforts in the application of artificial intelligence to taxon identification. Using the North Atlantic deep sea as a case study, we propose a database structure to facilitate standardisation of morphospecies image catalogues between research groups and support future use in multiple front-end applications. We also propose a framework for coordination of international efforts to develop reference guides for the identification of marine species from images. The proposed structure maps to the Darwin Core standard to allow integration with existing databases. We suggest a management framework where high-level taxonomic groups are curated by a regional team, consisting of both end users and taxonomic experts. We identify a mechanism by which overall quality of data within a common reference guide could be raised over the next decade. Finally, we discuss the role of a common reference standard in advancing marine ecology and supporting sustainable use of this ecosystem

Seafloor litter sorting in different domains of Cap de Creus continental shelf and submarine canyon (NW Mediterranean Sea)

14 pages, 8 figures, 2 tables, supplementary material https://doi.org/10.1016/j.marpolbul.2020.111744We analyzed litter occurrence in 68 underwater video transects performed on the middle/outer continental shelf and submarine canyon off Cap de Creus (NW Mediterranean), an area recently declared Site of Community Importance (SCI). Low densities of urban litter were registered on the shelf (7.2 items ha−1), increasing in abundance towards the deepest part of the submarine canyon, with 188 items ha−1 below 1000 m depth. We hypothesize that the strong bottom currents that recurrently affect this area efficiently move litter objects from the shelf towards the deep. Of all litter items, approximately 50% had a fishing-related origin, mostly longlines entangled on rocks in the canyon head and discarded trawl nets in deeper areas. Over 10% of cold-water colonies observed had longlines entangled, indicating the harmful effects of such practices over benthic habitats. These results should be considered when designing mitigation measures to reduce litter pollution in Cap de Creus SCIThe European Project HERMES (Goce-CT-2005-511234-I), the Spanish Project DEEP CORAL (CTM2005-07756-C02-02/MAR) and the Acciones Complementarias (CTM2007-28758-E/MAR) supported the 2007 cruise on board R/V Garcia del Cid with the manned submersible JAGO. Fundació “la Caixa” sponsored the PROMARES ROV cruise of the University of Barcelona, for which IEO and CSIC provided the Liropus 2000 ROV and R/V Sarmiento de Gamboa, respectively. The EU project Life+ Indemares (LIFE07/NAT/E/000732) funded the 2009, 2010 & 2012 cruises on board R/V Garcia del Cid and the littoral surveys with Bleeper EVO in 2009 and 2013. Numerical simulations were performed using HPC resources from the CALMIP platform (French region Occitanie) under grant P09115. The SYMPHONIE model is distributed by the SIROCCO group (https://sirocco.obs-mip.fr). This work also is a contribution of project IDEM (Implementation of the MSFD to the DEep Mediterranean Sea, ref. 11.0661/2017/750680/SUB/ENV.C2) funded by DG Environment of the European Commission, and the research network Red Española sobre BAsuras MARinas (BAMAR, CGL2016-81854-REDT) coordinated by the University of Barcelona. CTM2005-07756-C02-02/MAR) and the CRG Marine Geosciences received funding from Generalitat de Catalunya autonomous government (Ref. 2017 SRG 315)With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)Peer reviewe

Spatial distributions, environmental drivers and co-existence patterns of key cold-water corals in the deep sea of the Azores (NE Atlantic)

Habitat-forming cold-water corals (CWCs) represent a key component of deep-sea benthic communities and a priority target for conservation. Although research efforts have been mounting to try and identify the drivers of CWC distributions, progress has been limited by the scarcity of ecological data. The present work employs habitat suitability models (HSMs) to estimate spatial distributions, environmental drivers and co-existence patterns of 14 habitat-forming CWCs in the Azores, an area considered a hotspot of coral diversity in the Atlantic. The modelled CWCs showed a strong bathymetric zonation, which seems to be determined by the vertical stratification of water masses in the region. In particular, the modelled CWCs can be clustered in four groups named after the isopycnal (vertical) layers in which Atlantic water masses are organized: species restricted to upper water masses, species extending down from upper water masses, species restricted to intermediate water masses and species extending up from deep water masses. Horizontal patterns further indicate that the Azores Current and different production regimes north and south of the archipelago likely influence the distribution of CWCs in sub-surface waters. Such results have important implications for the regional management of deep-sea benthic communities and, in particular, for the design of representative networks of protected areas. The combined habitat of all modelled species covered only 11%. Given that they all possess the characteristics of benthic foundation organisms and represent indicator taxa of vulnerable marine ecosystems all the modelled species should be viewed as important targets for conservation. The lace coral Errina dabneyi deserves particular attention since this species appears to be endemic to the Azores and has a very limited estimated distribution.This work contributes to the PO2020 MapGES (Acores-01-0145-FEDER-000056) research project and to the European Union’s Horizon 2020 research and innovation programme under grant agreement No 678760 (ATLAS), No 818123 (iAtlantic) and No 824077 (EUROFLEETS+). This output reflects only the authors' views and the European Union cannot be held responsible for any use that may be made of the information contained therein. We acknowledge all projects and programs that collected occurrence data of cold-water coral species in the Azores region. Records in the COLETA database were originally collected by fisheries observer programs during the CORAZON project (FCT No PTDC/MAR/72169/2006), HERMIONE project (FP7 No 226354) and CoralFISH (FP7 GA 213144) harbour sampling programs; CoralFISH, DiscardLess (H2020 No 633680), MERCES (H2020 No 689518) and SPONGES (H2020 No 679849). Records were also provided by the fisheries survey programs ARQDAÇO (1995–2019), OASIS (FP7 No EVK3-CT-2002-00073), CoralFISH, CONDOR (EEA grants No PT0040/2008), PESCPROF (Interreg IIIB/MAC/4.2/M12), DEECON (FCT EURODEEP/0002/2007) and BIOMETORE (EEA grants No PT02), and by the FISHOR experimental bottom trawl surveys. Finally, occurrence records were also made available by multiple ROV, submersible and towed video surveys such as those conducted within the MapGES, BIOMETORE, Estrutura de Missão para Extensão da Plataforma Continental (EMEPC; Cruzeiro Científico EMEPC/LUSO/Açores/2009), MEDWAVES (ATLAS No 678760, with logistic and technical assistance from the UTM –CSIC– and the financial support from the Spanish Ministry of Economy, Industry and Competitivity), Blue Azores 2018 (National Geographic Pristine Seas program, Oceano Azul Foundation, and Waitt Institute), NICO 12 Expedition and Pelagia Rainbow 2019 (64PE441, 64PE454, and 64PE456; Netherlands Organisation for Scientific Research NWO for funding and Royal Netherlands Institute for Sea Research NIOZ for organising the Netherlands Initiative Changing Oceans NICO expedition in 2018), TREASURE (RV Pelagia cruises 64PE388, 64PE398, 64PE412, NWO-TTW grant 13273 and Topsector Water), and iMAR 2021 (RV Pelagia ship-time was provided free of charge as part of the iMAR project which received funding from the European Union's H2020 Research & Innovation Programme under grant agreement No 824077 EUROFLEETS+). We deeply thank all fisheries observers, PIs, crews and scientists that participated in all these sampling programs. GHT was supported by the DRCT (M3.1. a/F/052/2015). TM was supported by Program Investigador FCT (IF/01194/2013), and the IFCT Exploratory Project (IF/01194/2013/CP1199/CT0002) from the Fundação para a Ciência e Tecnologia (POPH and QREN). TM and MCS were also supported by the FCT-IP Program Stimulus of Scientific Employment (CCCIND/03345/2020 and CCCIND/03346/2020, respectively) and the H2020 programme No 689518 (MERCES) and No 818123 (iAtlantic). CD-C was supported by the PO2020 projects MapGES and DeepWalls (Acores-01-0145-FEDER-000056 and Acores-01-0145-FEDER-000124) and by the FCT-IP Project UIDP/05634/2020. CKP received support from the Operational Program Azores 2020, through the Fund 01-0145-FEDER-000140 ″MarAZ Researchers: Consolidate a body of researchers in Marine Sciences in the Azores” of the European Union. We also acknowledge funds through the FCT – Foundation for Science and Technology, I.P., under the project OKEANOS UIDB/05634/2020 and UIDP/05634/2020 and through the FCT Regional Government of the Azores under the project M1.1. A/REEQ.CIENTÍFICO UI&D/2021/010.Peer reviewe

Detrimental effects of ocean acidification on the economically important Mediterranean red coral (Corallium rubrum)

The mean predicted decrease of 0.3-0.4 pH units in the global surface ocean by the end of the century has prompted urgent research to assess the potential effects of ocean acidification on the marine environment, with strong emphasis on calcifying organisms. Among them, the Mediterranean red coral (Corallium rubrum) is expected to be particularly susceptible to acidification effects, due to the elevated solubility of its Mg-calcite skeleton. This, together with the large overexploitation of this species, depicts a bleak future for this organism over the next decades. In this study, we evaluated the effects of low pH on the species from aquaria experiments. Several colonies of C. rubrum were long-term maintained for 314 days in aquaria at two different pH levels (8.10 and 7.81, pHT). Calcification rate, spicule morphology, major biochemical constituents (protein, carbohydrates and lipids) and fatty acids composition were measured periodically. Exposure to lower pH conditions caused a significant decrease in the skeletal growth rate in comparison with the control treatment. Similarly, the spicule morphology clearly differed between both treatments at the end of the experiment, with aberrant shapes being observed only under the acidified conditions. On the other hand, while total organic matter was significantly higher under low pH conditions, no significant differences were detected between treatments regarding total carbohydrate, lipid, protein and fatty acid composition. However, the lower variability found among samples maintained in acidified conditions relative to controls, suggests a possible effect of pH decrease on the metabolism of the colonies. Our results show, for the first time, evidence of detrimental ocean acidification effects on this valuable and endangered coral species

Climate change considerations are fundamental to management of deep‐sea resource extraction

Climate change manifestation in the ocean, through warming, oxygen loss, increasing acidification, and changing particulate organic carbon flux (one metric of altered food supply), is projected to affect most deep-ocean ecosystems concomitantly with increasing direct human disturbance. Climate drivers will alter deep-sea biodiversity and associated ecosystem services, and may interact with disturbance from resource extraction activities or even climate geoengineering. We suggest that to ensure the effective management of increasing use of the deep ocean (e.g., for bottom fishing, oil and gas extraction, and deep-seabed mining), environmental management and developing regulations must consider climate change. Strategic planning, impact assessment and monitoring, spatial management, application of the precautionary approach, and full-cost accounting of extraction activities should embrace climate consciousness. Coupled climate and biological modeling approaches applied in the water and on the seafloor can help accomplish this goal. For example, Earth-System Model projections of climate-change parameters at the seafloor reveal heterogeneity in projected climate hazard and time of emergence (beyond natural variability) in regions targeted for deep-seabed mining. Models that combine climate-induced changes in ocean circulation with particle tracking predict altered transport of early life stages (larvae) under climate change. Habitat suitability models can help assess the consequences of altered larval dispersal, predict climate refugia, and identify vulnerable regions for multiple species under climate change. Engaging the deep observing community can support the necessary data provisioning to mainstream climate into the development of environmental management plans. To illustrate this approach, we focus on deep-seabed mining and the International Seabed Authority, whose mandates include regulation of all mineral-related activities in international waters and protecting the marine environment from the harmful effects of mining. However, achieving deep-ocean sustainability under the UN Sustainable Development Goals will require integration of climate consideration across all policy sectors