Viminella flagellum and Dentomuricea meteor specimens were collected from scientific longline fishing in the Condor Seamount (38˚08′N, 29˚05′W). Food incorporation of two co-occurring species Viminella flagellum and Dentomuricea meteor was measured under laboratory conditions by tissue incorporation of stable isotopes 13C and 15N. Specimens were kept in 35 l flow-through aquaria. Experiments lasted for 6 days, with feeding incubations lasting for 12 hours, while the feeding episodes happened, the flow-through system was closed creating a recirculating system where water currents were created by a rotating engine. Food incorporation was measured under two different flow speeds (2 and 4 cm/s) and under two different conditions: competition (the two species together) and control conditions (each species tested individually).

For accurate 3D photogrammetric measurements of corals under laboratory conditions, two prototypes (Azores 3D system and Barcelona 3D system) and a final setup (Coruña 3D system) were presented. These setups were designed to obtain a complete set of images of a coral in an aquarium and create accurate 3D reconstructions. A total of 24 (Azores), 177 (Barcelona) and 120 (Coruña) 3D reconstructions of cold-water corals were used to evaluate the systems. The effectiveness of the three systems was assessed by taking into account the total scale error of the 3D reconstructions. The total scale error is the difference between the input scale bar lengths and the measured distance between two-point markers. Here, we provide the total scale error from every reconstruction of each system.

This data publication contains maps resulting from spatial prioritisations conducted for the iAtlantic D5.3 report on Systematic Conservation Planning of the wider Atlantic Ocean based on results generated by the iAtlantic project. The maps were produced using the prioritizr R package (Hanson et al. 2023), which identifies priority areas for achieving specific conservation goals while minimising costs. The various prioritisations were developed to address multiple research questions related to: (1) identifying priority areas for conservation and restoration, (2) transboundary conservation, (3) climate-smart conservation planning, and (4) protecting 30% of the Atlantic Ocean, including 10% under strict protection. The results are organised into subfolders based on the research questions addressed and further categorised into data-rich and data-poor regions, along with aggregate results for each region. Further, the results are organised into subfolders representing multiple scenarios executed using various cost layers, including area-based, Global Fishing Watch (GFW, 2023) benthic, GFW total fishing, Global Fisheries Landings (GFL, Watson 2019) v4.0 benthic, and GFL v4.0 total landings. Each map filename provides descriptive information about the executed scenario.

We report the results of a series of experiments investigating the combined effects of ocean acidification and suspended natural benthic sediments (NS) generated during bottom trawling on the early life stages of the cold-water coral Desmophyllum pertusum (syn. Lophelia pertusa). The experiment was conducted at the Tjärnö Marine Laboratory Facilities (University of Gothenburg, Sweden). For each experiment, the larvae/embryos were exposed to four different treatments: (1) current pCO2 (control): mimicking present-day pCO2/pH condition (pCO2 400 µatm; ambient pHT: 8.01), (2) high pCO2: a scenario reflecting the IPCC RCP8.5 prediction (pCO2 1000 µatm; low pHT: 7.63), (3) current pCO2 + NS (5 mg/L), and (4) high pCO2 + NS (5 mg/L): with the introduction of natural benthic sediments (NS) at a concentration of 5 mg/mL. The NS were collected at ~130 m water depth from a regularly trawled soft bottom close to the reef site of Säcken in the Northern Koster-fjord in Sweden, and the grain sizes ≤ 63 μm were used for the experiment. Embryos and larvae were exposed to the different treatments in 75 mL culture flasks mounted on a rotating plankton wheel to keep sediments in suspension. This second experiment examined the effects on larval survival and swimming speed in two sub-experiments: A) short-term exposure (48 hours) and B) long-term exposure (1 week). This dataset presents the results for larval development under short-term exposure.

Here, we report the results of a multiple stressor experiment combining impacts of ocean acidification and Polymetallic sulfide (PMS) deposits produced by deep-sea mining on larval survival of the deep-sea coral Desmophyllum pertusum (syn. Lophelia pertusa). Adult colonies of D. pertusum were collected in December and January 2022 at Tisler reef, at depths between 100-120 m. Adults were maintained in aquaria and after spawning, embryos were collected and left to develop to 7-day larvae. On day 7, larvae were exposed to four experimental treatments and their combinations: two pCO2 treatments recreating present conditions (400 ppm), and conditions projected to the end of the century (RCP8.5, 1000 ppm), as well as two mining treatments corresponding to PMS particles (concentration 5 mg/L), and their leachates. Survival was monitored every 24h.

We report the results of a land-based experiment testing the cumulative effects of copper (Cu) exposure and ocean acidification (OA). Corals were obtained as by-catch during an experimental long-line fisheries campaign (CONDOR monitoring program, Okeanos-University of the Azores) on the Condor Seamount (38°54′N, 29°05′W), Azores Archipelago, at 200 m depth in October 2019. The experiment was undertaken at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores) where corals were exposed to four OA/Cu-contamination scenarios: (1) ambient pCO2/pH level as measured in situ conditions (385 μatm/ pH 8.09); (2) high pCO2/reduced pH (IPCC RCP8.5 scenario, 1000 μatm/ pH 7.73); (3) ambient pCO2/pH level and additional Cu concentration (60 µg/l); (4) high pCO2/reduced pH and additional Cu concentration (60 µg/l). The pH/pCO2 modification was achieved by bubbling seawater with either pure CO2 (to increase pCO2) or CO2 low air (to decrease pCO2). The copper concentration used in this experiment followed a trial simulating a polymetallic particles plume release during a potential deep-sea mining event. This sublethal concentration was found to be the highest copper concentration dissolved in seawater.Seawater physical-chemical parameters were measured daily in each chamber. Temperature, pH and oxygen saturation were measured manually in each aquaria every day using a Mettler-Toledo S8 glass and a Fibox4 (PreSens) with an Oxygen Probe PSt3.

We report the results of a land-based experiment testing the cumulative effects of copper (Cu) exposure and ocean acidification (OA). Corals were obtained as by-catch during an experimental long-line fisheries campaign (CONDOR monitoring program, Okeanos-University of the Azores) on the Condor Seamount (38°54′N, 29°05′W), Azores Archipelago, at 200 m depth in October 2019. The experiment was undertaken at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores) where corals were exposed to four OA/Cu-contamination scenarios: (1) ambient pCO2/pH level as measured in situ conditions (385 μatm/ pH 8.09); (2) high pCO2/reduced pH (IPCC RCP8.5 scenario, 1000 μatm/ pH 7.73); (3) ambient pCO2/pH level and additional Cu concentration (60 µg/l); (4) high pCO2/reduced pH and additional Cu concentration (60 µg/l). The pH/pCO2 modification was achieved by bubbling seawater with either pure CO2 (to increase pCO2) or CO2 low air (to decrease pCO2). The copper concentration used in this experiment followed a trial simulating a polymetallic particles plume release during a potential deep-sea mining event. This sublethal concentration was found to be the highest copper concentration dissolved in seawater. Metabolic (CA and Hsp70), oxidative damage (SOD, MDA) and detoxification (GST) biomarkers were measured in 4 corals from each treatment at the end of the experiment, using a multiplate spectrophotometer reader.

We report the results of a land-based experiment testing the cumulative effects of copper (Cu) exposure and ocean acidification (OA). Corals were obtained as by-catch during experimental long-line fisheries campaigns on board R/V "Arquipélago" (ARQDAÇO monitoring program, University of the Azores) at Baixa de São Mateus at 185 m depth in April 2019. The experiment was undertaken at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores) where corals were exposed to four OA/Cu-contamination scenarios: (1) ambient pCO2/pH level as measured in situ conditions (385 μatm/ pH 8.09); (2) high pCO2/reduced pH (IPCC RCP8.5 scenario, 1000 μatm/ pH 7.73); (3) ambient pCO2/pH level and additional Cu concentration (60 µg/l); (4) high pCO2/reduced pH and additional Cu concentration (60 µg/l). The pH/pCO2 modification was achieved by bubbling seawater with either pure CO2 (to increase pCO2) or CO2 low air (to decrease pCO2). The copper concentration used in this experiment followed a trial simulating a polymetallic particles plume release during a potential deep-sea mining event. This sublethal concentration was found to be the highest copper concentration dissolved in seawater.Seawater physical-chemical parameters were measured daily in each chamber. Temperature, pH and oxygen saturation were measured manually in each aquaria every day using a Mettler-Toledo S8 glass and a Fibox4 (PreSens) with an Oxygen Probe PSt3.

We report the results of a series of experiments investigating the combined effects of ocean acidification and suspended natural benthic sediments (NS) generated during bottom trawling on the early life stages of the cold-water coral Desmophyllum pertusum (syn. Lophelia pertusa). The experiment was conducted at the Tjärnö Marine Laboratory Facilities (University of Gothenburg, Sweden). For each experiment, the larvae/embryos were exposed to four different treatments: (1) current pCO2 (control): mimicking present-day pCO2/pH condition (pCO2 400 µatm; ambient pHT: 8.01), (2) high pCO2: a scenario reflecting the IPCC RCP8.5 prediction (pCO2 1000 µatm; low pHT: 7.63), (3) current pCO2 + NS (5 mg/L), and (4) high pCO2 + NS (5 mg/L): with the introduction of natural benthic sediments (NS) at a concentration of 5 mg/mL. The NS were collected at ~130 m water depth from a regularly trawled soft bottom close to the reef site of Säcken in the Northern Koster-fjord in Sweden, and the grain sizes ≤ 63 μm were used for the experiment. Embryos and larvae were exposed to the different treatments in 75 mL culture flasks mounted on a rotating plankton wheel to keep sediments in suspension. In this first experiment, embryos were exposed for 48 hours to assess potential impacts on larval survival, development from the first division to the blastula stage, and developmental abnormalities. This dataset presents the results for embryo sizes.

The objective of this study is to determine the effects of ocean acidification (OA) on the survival, development and swimming behaviour of embryos of the deep-sea coral Desmophyllum pertusum (syn. Lophelia pertusa). Upon spawning, fertilized embryos were collected and exposed to two pCO2 treatments corresponding to present pCO2 conditions (400 ppm) and future pCO2 conditions predicted under scenario IPCC RCP8.5 for the end of the century (1000 ppm). We monitored survival daily and we measured swimming velocity on day 9 after spawning. Temperature and pH were measured every 24h, salinity was measured every other day, and water samples were collected during the first and last day of the experiment to determine total alkalinity (TA).This dataset includes data on the effects of OA on embryo and larval survival of the deep-sea coral Desmophyllum pertusum. Embryos (age: first cleavage and 2 cell stage) were exposed to two acidification (pCO2) treatments: present pCO2 conditions (400 ppm) and future pCO2 conditions predicted under RCP8.5 for the end of the century (1000 ppm) and reared for a total of nine days. We counted embryos and larvae daily to determine larval survival under the two treatments.

We report the results of a land-based experiment testing the cumulative effects of copper (Cu) exposure and ocean acidification (OA). Corals were obtained as by-catch during an experimental long-line fisheries campaign (CONDOR monitoring program, Okeanos-University of the Azores) on the Condor Seamount (38°54′N, 29°05′W), Azores Archipelago, at 200 m depth in October 2019. The experiment was undertaken at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores) where corals were exposed to four OA/Cu-contamination scenarios: (1) ambient pCO2/pH level as measured in situ conditions (385 μatm/ pH 8.09); (2) high pCO2/reduced pH (IPCC RCP8.5 scenario, 1000 μatm/ pH 7.73); (3) ambient pCO2/pH level and additional Cu concentration (60 µg/l); (4) high pCO2/reduced pH and additional Cu concentration (60 µg/l). The pH/pCO2 modification was achieved by bubbling seawater with either pure CO2 (to increase pCO2) or CO2 low air (to decrease pCO2). The copper concentration used in this experiment followed a trial simulating a polymetallic particles plume release during a potential deep-sea mining event. This sublethal concentration was found to be the highest copper concentration dissolved in seawater.Measurements of respiration were made immediately before the start of the experiment (T0) and after 9 days (T9, end of the experiment), when corals started to show tissue necrosis, using an oxygen meter Fibox4 with a PSt3 sensor (PreSens, Germany). Coral respiration rates were normalized to the coral surface area.

We report the results of a land-based experiment testing the cumulative effects of copper (Cu) exposure and ocean acidification (OA). Corals were obtained as by-catch during experimental long-line fisheries campaigns on board R/V "Arquipélago" (ARQDAÇO monitoring program, University of the Azores) at Baixa de São Mateus at 185 m depth in April 2019. The experiment was undertaken at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores) where corals were exposed to four OA/Cu-contamination scenarios: (1) ambient pCO2/pH level as measured in situ conditions (385 μatm/ pH 8.09); (2) high pCO2/reduced pH (IPCC RCP8.5 scenario, 1000 μatm/ pH 7.73); (3) ambient pCO2/pH level and additional Cu concentration (60 µg/l); (4) high pCO2/reduced pH and additional Cu concentration (60 µg/l). The pH/pCO2 modification was achieved by bubbling seawater with either pure CO2 (to increase pCO2) or CO2 low air (to decrease pCO2). The copper concentration used in this experiment followed a trial simulating a polymetallic particles plume release during a potential deep-sea mining event. This sublethal concentration was found to be the highest copper concentration dissolved in seawater.Measurements of respiration were made immediately before the start of the experiment (T0) and after 9 days (T9, end of the experiment), when corals started to show tissue necrosis, using an oxygen meter Fibox4 with a PSt3 sensor (PreSens, Germany). Coral respiration rates were normalized to the coral surface area.

We report the results of a series of experiments investigating the combined effects of ocean acidification and suspended natural benthic sediments (NS) generated during bottom trawling on the early life stages of the cold-water coral Desmophyllum pertusum (syn. Lophelia pertusa). The experiment was conducted at the Tjärnö Marine Laboratory Facilities (University of Gothenburg, Sweden). For each experiment, the larvae/embryos were exposed to four different treatments: (1) current pCO2 (control): mimicking present-day pCO2/pH condition (pCO2 400 µatm; ambient pHT: 8.01), (2) high pCO2: a scenario reflecting the IPCC RCP8.5 prediction (pCO2 1000 µatm; low pHT: 7.63), (3) current pCO2 + NS (5 mg/L), and (4) high pCO2 + NS (5 mg/L): with the introduction of natural benthic sediments (NS) at a concentration of 5 mg/mL. The NS were collected at ~130 m water depth from a regularly trawled soft bottom close to the reef site of Säcken in the Northern Koster-fjord in Sweden, and the grain sizes ≤ 63 μm were used for the experiment. Embryos and larvae were exposed to the different treatments in 75 mL culture flasks mounted on a rotating plankton wheel to keep sediments in suspension. In this first experiment, embryos were exposed for 48 hours to assess potential impacts on larval survival, development from the first division to the blastula stage, and developmental abnormalities. This dataset presents the percentage of embryonic abnormalities.

We report the results of a series of experiments investigating the combined effects of ocean acidification and suspended natural benthic sediments (NS) generated during bottom trawling on the early life stages of the cold-water coral Desmophyllum pertusum (syn. Lophelia pertusa). The experiment was conducted at the Tjärnö Marine Laboratory Facilities (University of Gothenburg, Sweden). For each experiment, the larvae/embryos were exposed to four different treatments: (1) current pCO2 (control): mimicking present-day pCO2/pH condition (pCO2 400 µatm; ambient pHT: 8.01), (2) high pCO2: a scenario reflecting the IPCC RCP8.5 prediction (pCO2 1000 µatm; low pHT: 7.63), (3) current pCO2 + NS (5 mg/L), and (4) high pCO2 + NS (5 mg/L): with the introduction of natural benthic sediments (NS) at a concentration of 5 mg/mL. The NS were collected at ~130 m water depth from a regularly trawled soft bottom close to the reef site of Säcken in the Northern Koster-fjord in Sweden, and the grain sizes ≤ 63 μm were used for the experiment. Embryos and larvae were exposed to the different treatments in 75 mL culture flasks mounted on a rotating plankton wheel to keep sediments in suspension. This second experiment examined the effects on larval survival and swimming speed in two sub-experiments: A) short-term exposure (48 hours) and B) long-term exposure (1 week). This dataset presents the results for larval survival under short-term exposure.

We report the results of a series of experiments investigating the combined effects of ocean acidification and suspended natural benthic sediments (NS) generated during bottom trawling on the early life stages of the cold-water coral Desmophyllum pertusum (syn. Lophelia pertusa). The experiment was conducted at the Tjärnö Marine Laboratory Facilities (University of Gothenburg, Sweden). For each experiment, the larvae/embryos were exposed to four different treatments: (1) current pCO2 (control): mimicking present-day pCO2/pH condition (pCO2 400 µatm; ambient pHT: 8.01), (2) high pCO2: a scenario reflecting the IPCC RCP8.5 prediction (pCO2 1000 µatm; low pHT: 7.63), (3) current pCO2 + NS (5 mg/L), and (4) high pCO2 + NS (5 mg/L): with the introduction of natural benthic sediments (NS) at a concentration of 5 mg/mL. The NS were collected at ~130 m water depth from a regularly trawled soft bottom close to the reef site of Säcken in the Northern Koster-fjord in Sweden, and the grain sizes ≤ 63 μm were used for the experiment. Embryos and larvae were exposed to the different treatments in 75 mL culture flasks mounted on a rotating plankton wheel to keep sediments in suspension. In this first experiment, embryos were exposed for 48 hours to assess potential impacts on larval survival, development from the first division to the blastula stage, and developmental abnormalities. This dataset presents the results for embryonic survival.

We report the results of a series of experiments investigating the combined effects of ocean acidification and suspended natural benthic sediments (NS) generated during bottom trawling on the early life stages of the cold-water coral Desmophyllum pertusum (syn. Lophelia pertusa). The experiment was conducted at the Tjärnö Marine Laboratory Facilities (University of Gothenburg, Sweden). For each experiment, the larvae/embryos were exposed to four different treatments: (1) current pCO2 (control): mimicking present-day pCO2/pH condition (pCO2 400 µatm; ambient pHT: 8.01), (2) high pCO2: a scenario reflecting the IPCC RCP8.5 prediction (pCO2 1000 µatm; low pHT: 7.63), (3) current pCO2 + NS (5 mg/L), and (4) high pCO2 + NS (5 mg/L): with the introduction of natural benthic sediments (NS) at a concentration of 5 mg/mL. The NS were collected at ~130 m water depth from a regularly trawled soft bottom close to the reef site of Säcken in the Northern Koster-fjord in Sweden, and the grain sizes ≤ 63 μm were used for the experiment. Embryos and larvae were exposed to the different treatments in 75 mL culture flasks mounted on a rotating plankton wheel to keep sediments in suspension. The second experiment examined the effects on larval survival and swimming speed in two sub-experiments: A) short-term exposure (48 hours) and B) long-term exposure (1 week). This dataset presents the results for larval survival under long-term exposure.

We report the results of a series of experiments investigating the combined effects of ocean acidification and suspended natural benthic sediments (NS) generated during bottom trawling on the early life stages of the cold-water coral Desmophyllum pertusum (syn. Lophelia pertusa). The experiment was conducted at the Tjärnö Marine Laboratory Facilities (University of Gothenburg, Sweden). For each experiment, the larvae/embryos were exposed to four different treatments: (1) current pCO2 (control): mimicking present-day pCO2/pH condition (pCO2 400 µatm; ambient pHT: 8.01), (2) high pCO2: a scenario reflecting the IPCC RCP8.5 prediction (pCO2 1000 µatm; low pHT: 7.63), (3) current pCO2 + NS (5 mg/L), and (4) high pCO2 + NS (5 mg/L): with the introduction of natural benthic sediments (NS) at a concentration of 5 mg/mL. The NS were collected at ~130 m water depth from a regularly trawled soft bottom close to the reef site of Säcken in the Northern Koster-fjord in Sweden, and the grain sizes ≤ 63 μm were used for the experiment. Embryos and larvae were exposed to the different treatments in 75 mL culture flasks mounted on a rotating plankton wheel to keep sediments in suspension. The second experiment examined the effects on larval survival and swimming speed in two sub-experiments: A) short-term exposure (48 hours) and B) long-term exposure (1 week). This dataset presents the results for larval swimming speeds under short-term exposure.

We report the results of a short-term experiment testing the effects of microplastics (MP) on the larvae of the cold-water coral Desmophyllum pertusum (syn. Lophelia pertusa). The experiment was conducted at the Tjärnö Marine Laboratory Facilities (University of Gothenburg, Sweden). To simulate MP pollution, we used 6 μm yellow-green fluorescent polystyrene microbeads (catalog no: 17156, Polysciences). The experimental design consisted of three treatments: control treatment with (1) no MP addition (0 MP/mL), (2) addition of 1000 pristine MP/mL, and (3) addition of 1000 biofouled MP/mL. Larvae were exposed to the different treatments in 75 mL culture flasks mounted on a rotating plankton wheel to keep sediments in suspension. After a 24-hour period, the potential impact of MP on larval survival was analyzed.

We report the results of a land-based experiment testing the cumulative effects of copper (Cu) exposure and ocean acidification (OA). Corals were obtained as by-catch during experimental long-line fisheries campaigns on board R/V "Arquipélago" (ARQDAÇO monitoring program, University of the Azores) at Baixa de São Mateus at 185 m depth in April 2019. The experiment was undertaken at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores) where corals were exposed to four OA/Cu-contamination scenarios: (1) ambient pCO2/pH level as measured in situ conditions (385 μatm/ pH 8.09); (2) high pCO2/reduced pH (IPCC RCP8.5 scenario, 1000 μatm/ pH 7.73); (3) ambient pCO2/pH level and additional Cu concentration (60 µg/l); (4) high pCO2/reduced pH and additional Cu concentration (60 µg/l). The pH/pCO2 modification was achieved by bubbling seawater with either pure CO2 (to increase pCO2) or CO2 low air (to decrease pCO2). The copper concentration used in this experiment followed a trial simulating a polymetallic particles plume release during a potential deep-sea mining event. This sublethal concentration was found to be the highest copper concentration dissolved in seawater.Metabolic (CA and Hsp70), oxidative damage (SOD, MDA) and detoxification (GST) biomarkers were measured in 4 corals from each treatment at the end of the experiment, using a multiplate spectrophotometer reader.

We report the results of a short-term experiment testing the effects of microplastics (MP) on the larvae of the cold-water coral Desmophyllum pertusum (syn. Lophelia pertusa). The experiment was conducted at the Tjärnö Marine Laboratory Facilities (University of Gothenburg, Sweden). To simulate MP pollution, we used 6 μm yellow-green fluorescent polystyrene microbeads (catalog no: 17156, Polysciences). The experimental design consisted of three treatments: control treatment with (1) no MP addition (0 MP/mL), (2) addition of 1000 pristine MP/mL, and (3) addition of 1000 biofouled MP/mL. Larvae were exposed to the different treatments in 75 mL culture flasks mounted on a rotating plankton wheel to keep sediments in suspension. After a 24-hour period, the potential impact of MP on larval swimming speed was analyzed using image analysis software (Meijering et al. 2012).

We report the results of an aquaria-based experiment testing the effects of simulated sediment plumes generated during mining activities for the extraction of ferromanganese nodules in the Clarion-Clipperton Fracture Zone (CCFZ), northeastern equatorial Pacific Ocean, and seafloor massive sulfides from a hydrothermal vent field in the Azores, northeast Atlantic, on the physiology of the cold-water octocoral Dentomuricea aff. meteor. Coral fragments were exposed to five experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) suspended plumes of abyssal sediments from nodule fields at a concentration of 10 mg/l; (2) suspended plumes of abyssal sediments from nodule fields at a concentration of 50 mg/l; (3) hydrothermal polymetallic sulphide particles at a concentration of 10 mg/l; (4) hydrothermal polymetallic sulphide particles at a concentration of 50 mg/l; and (5) a control treatment with no sediment addition. Seawater physical-chemical parameters were measured daily in each aquarium. Temperature and pH were measured manually in each aquaria every day using a Mettler-Toledo Seven2Go pH /Ion meter S8, salinity was measured with a S30 SevenEasyTM conductivity meter and oxygen concentration was measured with a Fibox4 (PreSens) with a Oxygen Dipping Probe DP-PSt3.

We report the results of an aquaria-based experiment testing the effects of simulated sediment plumes generated during mining activities for the extraction of ferromanganese nodules in the Clarion-Clipperton Fracture Zone (CCFZ), northeastern equatorial Pacific Ocean, and seafloor massive sulfides from a hydrothermal vent field in the Azores, northeast Atlantic, on the physiology of the cold-water octocoral Dentomuricea aff. meteor. Coral fragments were exposed to five experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) suspended plumes of abyssal sediments from nodule fields at a concentration of 10 mg/l (2) suspended plumes of abyssal sediments from nodule fields at a concentration of 50 mg/l; (3) hydrothermal polymetallic sulphide particles at a concentration of 10 mg/l; (4) hydrothermal polymetallic sulphide particles at a concentration of 50 mg/l; and (5) a control treatment with no sediment addition. The surface area of the coral tissue lost during the experiment was quantified using photographs of the coral fragments and ImageJ software. Measurements were made every week for a period of 4 weeks.

We conducted a medium-term (4 months) multiple stressor experiment with the cold-water coral Desmophyllum dianthus under future environmental conditions (IPCC RCP 8.5 scenarios for 2100), and sediment plumes generated during the potential extraction of seafloor massive sulphides. The experiment followed a two-step approach, where during the first 3 months, corals were exposed to four different treatments combining predicted scenarios of ocean acidification (pCO2/pH) and food availability. Two levels of pCO2 conditions were considered: natural habitat present day conditions (~500 µatm, 720 m depth) and IPCC RCP8.5 scenario (1000 µatm; IPCC, 2019), corresponding to pHT values of 7.93 and 7.66, respectively. In addition, two food availability regimes were recreated: high frequency of feeding (food delivered twice a day / 7 days a week) and low frequency of feeding (food delivered every other day). There were six replicate 13 L aquaria per treatment (4 D. dianthus per aquaria) at a temperature of 10.5 ± 0.1 ºC. During the fourth month of the experiment, suspended polymetallic sulphide particles generated during potential mining activities were added to half of the aquaria under the climate change scenarios at a concentration of 10 mg/l, making 8 treatments in a fully crossed experimental design for the 3 factors tested (OA, food, mining particles). Measurements of respiration were made at different times during the experiments: T0 (immediately before the start of the experiment), 2, 4, 9 and 14 weeks, using an oxygen meter Fibox4 with PSt3 sensors (PreSens, Germany). Coral respiration rates were normalized to the coral skeletal surface area.

We report the results of an aquaria-based experiment testing the effects of simulated sediment plumes generated during mining activities for the extraction of ferromanganese nodules in the Clarion-Clipperton Fracture Zone (CCFZ), northeastern equatorial Pacific Ocean, and seafloor massive sulfides from a hydrothermal vent field in the Azores, northeast Atlantic, on the physiology of the cold-water octocoral Dentomuricea aff. meteor. Coral fragments were exposed to five experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) suspended plumes of abyssal sediments from nodule fields at a concentration of 10 mg/l; (2) suspended plumes of abyssal sediments from nodule fields at a concentration of 50 mg/l; (3) hydrothermal polymetallic sulphide particles at a concentration of 10 mg/l; (4) hydrothermal polymetallic sulphide particles at a concentration of 50 mg/l; and (5) a control treatment with no sediment addition. Measurements of respiration were made at T0 (immediately before the start of the experiment), and every week until the end of the experiment using an oxygen meter Fibox4 and PSt3 sensor spots (PreSens, Germany). Coral respiration rates were normalized to the coral skeletal surface area.

We conducted a medium-term (4 months) multiple stressor experiment with the cold-water coral Desmophyllum dianthus under future environmental conditions (IPCC RCP 8.5 scenarios for 2100), and sediment plumes generated during the potential extraction of seafloor massive sulphides. The experiment followed a two-step approach, where during the first 3 months, corals were exposed to four different treatments combining predicted scenarios of ocean acidification (pCO2/pH) and food availability. Two levels of pCO2 conditions were considered: natural habitat present day conditions (~500 µatm, 720 m depth) and IPCC RCP8.5 scenario (1000 µatm; IPCC, 2019), corresponding to pHT values of 7.93 and 7.66, respectively. In addition, two food availability regimes were recreated: high frequency of feeding (food delivered twice a day / 7 days a week) and low frequency of feeding (food delivered every other day). There were six replicate 13 L aquaria per treatment (4 D. dianthus per aquaria) at a temperature of 10.5 ± 0.1 ºC. During the fourth month of the experiment, suspended polymetallic sulphide particles generated during potential mining activities were added to half of the aquaria under the climate change scenarios at a concentration of 10 mg/l, making 8 treatments in a fully crossed experimental design for the 3 factors tested (OA, food, mining particles). Growth rates were measured using the buoyant weighing technique (Jokiel et al. 1978), using a balance (Mettler-Toledo ME204T) with a precision of 0.1 mg. Corals were weighed twice during the experiment: 1-2 weeks after the start of the experiment and just before the second phase of the experiment with PMS addition, which corresponded to a time interval of 63-71 days.

We conducted a medium-term (4 months) multiple stressor experiment with the cold-water coral Desmophyllum dianthus under future environmental conditions (IPCC RCP 8.5 scenarios for 2100), and sediment plumes generated during the potential extraction of seafloor massive sulphides. The experiment followed a two-step approach, where during the first 3 months, corals were exposed to four different treatments combining predicted scenarios of ocean acidification (pCO2/pH) and food availability. Two levels of pCO2 conditions were considered: natural habitat present day conditions (~500 µatm, 720 m depth) and IPCC RCP8.5 scenario (1000 µatm; IPCC, 2019), corresponding to pHT values of 7.93 and 7.66, respectively. In addition, two food availability regimes were recreated: high frequency of feeding (food delivered twice a day / 7 days a week) and low frequency of feeding (food delivered every other day). There were six replicate 13 L aquaria per treatment (4 D. dianthus per aquaria) at a temperature of 10.5 ± 0.1 ºC. During the fourth month of the experiment, suspended polymetallic sulphide particles generated during potential mining activities were added to half of the aquaria under the climate change scenarios at a concentration of 10 mg.L-1, making 8 treatments in a fully crossed experimental design for the 3 factors tested (OA, food, mining particles). Seawater physical-chemical parameters were measured daily in each aquarium. Temperature and pH were measured manually in each aquaria using a Mettler-Toledo Seven2Go pH /Ion meter S8, salinity was measured with a S30 SevenEasyTM conductivity meter, oxygen concentration was measured with a Fibox4 (PreSens) with a Oxygen Dipping Probe DP-PSt3.

We developed habitat suitability models for 14 vulnerable and foundation cold-water coral (CWC) taxa of the Azores (NE Atlantic) using GAM and MAXENT models. The modelled taxa are: Acanthogorgia spp., Callogorgia verticillata, Coralliidae spp., Dentomuricea aff. meteor, Desmophyllum pertusum, Errina dabneyi, Leiopathes cf. expansa, Madrepora oculata, Narella bellissima, Narella versluysi, Paracalyptrophora josephinae, Paragorgia johnsoni, Solenosmilia variabilis and Viminella flagellum. Models were built using a model grid having a cell size of a 1.13 x 1.11 km (i.e. about 0.01° in the UTM zone 26N projection). This resolution was considered a good compromise between the original resolution of occurrence and environmental data and our capacity to resolve suitable and unsuitable areas within the same geomorphological feature using model predictions. Study area and model background were limited to depths shallower than 2000 m where most of the sampling events took place. Predictors variables included bathymetric position indexes (5 km and 20 km radii), slope, particulate organic carbon flux, seawater chemistry (principal component of dissolved near-seafloor nutrient concentration and calcite/aragonite saturation levels) and near seafloor values of current speed, oxygen saturation and temperature. Presence records were obtained from two different sources: species annotations from underwater imagery (76%) and longline and handline bycatch records (24 %).The published data include: 1. Binary GAM and Maxent habitat suitability predictions. A bootstrap process (n = 100) evaluated the local confidence of model predictions. Each bootstrap iteration sampled occurrence data with replacement, fitted HSMs models and produced binary suitability maps based on sensitivity‐specificity sum maximization thresholds. Depending on the number of times individual raster cells were predicted as suitable they were classified as: low [1-30%), medium [30-70%) or high [70-100%] confidence suitable cells. This process was repeated independently for GAM and Maxent models. In raster layers: (3) identifies high-confidence suitable cells, (2) medium-confidence suitable cells, (1) low-confidence suitable cells and NAs unsuitable cells. 2. Local fuzzy matching of GAM and Maxent habitat suitability predictions. The level of similarity between the spatial distribution of GAM and Maxent binary predictions (low, medium and high confidence suitable cells) at a local (i.e. cell) level was measured considering two membership functions: category similarity, which assumed that some categories were more similar than others; distance decay, which defined the fuzzy similarity of two cells as (i) identical if they matched perfectly, (ii) linearly decreasing with distance if the matching category was found within a 2-cell radius (~2 km) or (iii) totally different when no matching category was found within a 2-cell radius. After combining the two membership functions similarity scores ranged from 0 (totally different) to 1 (identical). Values of similarity greater than 0.5 indicate raster cells that are more similar than different.3. Combined habitat suitability maps. Suitable raster cells of combined habitat suitability maps were classified as follows: (i) high confidence suitable cell (3 in raster layers), raster cell predicted as suitable with high-confidence by both GAM and Maxent models; (ii) medium confidence suitable cell (2 in raster layers), raster cell predicted as suitable with medium or high confidence by GAM, Maxent or both and with a local fuzzy similarity greater than 0.5; (iii) low confidence suitable cell (1 in raster layers), any other cell predicted as suitable by GAM and/or Maxent.4. Cold water coral richness based on habitat suitability predictions. The .tif file shows the number of taxa predicted as suitable for each raster cell. Note that only high confidence suitable cells of combined habitat suitability maps are considered.

This dataset includes 11 regional EUNIS-classified habitat maps (100-1000 km) and associated confidence maps that were created as a project milestone (Nr. 12) of the EU H2020 project 'iAtlantic'. The 12 iAtlantic regions encompass 1. Subpolar Mid-Atlantic Ridge, off Iceland MFRI, 2. Rockall Trough to PAP, 3. Central mid-Atlantic Ridge, 4. NW Atlantic, Gully Canyon, 5. Sargasso Sea, 6. Eastern Tropical North Atlantic, Cape Verde, 7. Equatorial Atlantic, Romanche Fracture Zone, 8. Slope & margin off Angola & Congo Lobe, 9. Benguela Current, Walvis Ridge to South Africa, 10. Brazil margin & Santos and Campos Basin, 11. Vitória-Trindade Seamount Chain and 12. Malvinas Current. For each of the regions 2-12, a shapefile of polygons classified according to the 2022 EUNIS classification level 3 and a second shapefile of the same polygons attributed with their confidence level according to the MESH Accuracy & Confidence Working approach was created. EUNIS classifications combined biozone and substrate data. Biozones were assigned from bathymetry. Where MBES was not available, GEBCO bathymetry was used. Substrate data were extracted from pre-existing geological/substrate mapping efforts and converted to EUNIS classifications via cross walks or, where substrate data were limited, substrate layers were modelled using Random Forest. The EUNIS habitat map for Region 4 was based on the pre-existing surficial geology compilation of the Scotian Shelf bioregion compiled by the Geological Survey of Canada. The EUNIS habitat map for Region 9 was based on the pre-existing South African habitat map that uses a modified IUCN hierarchical classification system. No additional information to that used in the EUSeaMap was available for Region 1. Therefore, shapefiles were not created for Region 1.

The antipatharian coral Antipathella wollastoni is commonly found in the Macaronesia (Cape Verde, Madeira, Canaries and the Azores Archipelago). In the Azores Archipelago the species forms dense populations and coral gardens on island slopes between 15-520 m water depth. Here, we present data from two experiments on the embryo and larval survival of A. wollastoni under two different seawater temperatures (21°C and 23­°C). Embryos were collected after spawning of mother colonies in aquaria. In the first experiment, we monitored the number of embryos for 24 h after spawning, while in the second experiment we monitored the number of embryos and planulae (larvae) for a total of 35 h.

We report the results of a series of experiments investigating the combined effects of ocean acidification and suspended natural benthic sediments (NS) generated during bottom trawling on the early life stages of the cold-water coral Desmophyllum pertusum (syn. Lophelia pertusa). The experiment was conducted at the Tjärnö Marine Laboratory Facilities (University of Gothenburg, Sweden). For each experiment, the larvae/embryos were exposed to four different treatments: (1) current pCO2 (control): mimicking present-day pCO2/pH condition (pCO2 400 µatm; ambient pHT: 8.01), (2) high pCO2: a scenario reflecting the IPCC RCP8.5 prediction (pCO2 1000 µatm; low pHT: 7.63), (3) current pCO2 + NS (5 mg/L), and (4) high pCO2 + NS (5 mg/L): with the introduction of natural benthic sediments (NS) at a concentration of 5 mg/mL. The NS were collected at ~130 m water depth from a regularly trawled soft bottom close to the reef site of Säcken in the Northern Koster-fjord in Sweden, and the grain sizes ≤ 63 μm were used for the experiment. Embryos and larvae were exposed to the different treatments in 75 mL culture flasks mounted on a rotating plankton wheel to keep sediments in suspension. The second experiment examined the effects on larval survival and swimming speed in two sub-experiments: A) short-term exposure (48 hours) and B) long-term exposure (1 week). This dataset presents the results for larval swimming speeds under long-term exposure.

In this dataset, we report the results of an aquaria experiment aiming at determining the impacts of Polymetallic sulfide (PMS) plumes of varying concentrations created by deep-sea mining on larval survival of the deep-sea coral Desmophyllum pertusum. Colonies of D. pertusum were collected in December 2022 and January 2023 at Tisler reef, at depths between 100-120 m. Adults were maintained in aquaria and after spawning, embryos were collected and left to develop to 7-day larvae. On day 7, larvae were exposed to four experimental treatments, recreating the potential effects of a PMS mining plume: two treatments contained PMS particles at concentrations of 2.5 mg/L and 5 mg/L respectively, and another two contained only the leachates of PMS particle solutions corresponding to the aforementioned PMS particle concentrations. Temperature was maintained at 8-8.5 °C and pHT at 8.01. Survival was checked by counting surviving larvae after 24h of exposure.

Trait-based approaches that complement taxonomic-based studies have increased in popularity among the scientific community over the last decades. The collection of biological and ecological characteristics of species (i.e., traits) provides insight into species and ecosystem vulnerability to environmental and anthropogenic changes, as well as ecosystem functioning. While most of the available trait databases to date contain essential information to understand the functional diversity of a taxonomic group or functional group based on size, the FUN Azores trait database has an ecosystem-based approach that provides a comprehensive assessment of diverse fauna (meio-, macro-, and megafauna) from benthic and pelagic environments in the Azores Marine Park; including ridges, seamounts, and hydrothermal vents. We used a collaborative approach involving 30 researchers with different expertise to develop the trait database; which contains compiled data on 14 traits representing morphological, behavioral, and life history characteristics for 1210 species, across 10 phyla.

The iMAR cruise “The Integrated assessment of the distribution of Vulnerable Marine Ecosystem along the Mid-Atlantic Ridge (MAR) in the Azores region” took place aboard the Research Vessel Pelagia of the Royal Netherlands Institute for Sea Research (NIOZ) between May 19th and June 2nd 2021. This expedition was funded by the SEA OCEANS program of Eurofleets+ and the H2020 European project iAtlantic, and was led by the University of the Azores (Portugal) in collaboration with the Hydrographic Institute and University of Porto (Portugal), the University of Aarhus (Denmark), the National Oceanography Center (United Kingdom), GEOMAR (Germany), the University Museum of Bergen (Norway), the PP Shirshov Institute of Oceanology (Russia), and the University of Vale do Itajaí (Brazil). During the iMAR cruise we performed 28 stations for multibeam surveys, summing 171:30 hours of surveys, 5,500 km2 of mapped seabed (mainly in the North portion of the MAR in the Exclusive Economic Zone around the Azores), in 8 main areas and during many of the 2,500 km of transits All multibeam data processing was treated by Leonor Neves de Sousa (Instituto Hidrográfico) with the software “CARIS HIPS & SIPS”.These are the .all files of multibeam row data about 28 stations, between 18 May and 2 June, with information about seamounts, ridges and depressions of the Mid-Atlantic Ridge in the Azores.

This dataset was produced during the iMAR cruise “The Integrated assessment of the distribution of Vulnerable Marine Ecosystem along the Mid-Atlantic Ridge (MAR) in the Azores region”, that took place aboard the Research Vessel Pelagia of the Royal Netherlands Institute for Sea Research between May 18th and June 2nd 2021. The iMAR cruise aimed to evaluate the role of the MAR in shaping latitudinal and trans-Atlantic patterns in deep-sea biogeography, connectivity and assemblages of deep-sea megafauna. This expedition was funded by the SEA OCEANS program of Eurofleets+ and the H2020 European project iAtlantic, and was led by the University of the Azores (Portugal) in collaboration with the Hydrographic Institute and University of Porto (Portugal), the University of Aarhus (Denmark), the National Oceanography Center (United Kingdom), GEOMAR (Germany), the University Museum of Bergen (Norway), the PP Shirshov Institute of Oceanology (Russia), and the University of Vale do Itajaí (Brazil). Nutrient analysis was performed according to Grasshoff et al, adopted for a 5 channel continues flow analyzer (Skalar San Plus, Skalar Analytical B. V., Breda, The Netherlands). Nitrite and nitrate+nitrite was measured using an ammonia buffer and sulfanilamide/alpha-Naphthylethylene diamine dihydrochloride colour reagent in phosphoric acid, with reduction of nitrate to nitrite by cadmium column of at least 80% measured reduction capacity (90-100% achieved), followed by quantification with spectrophotometric determination of the nitrite-azo dye at 540 nm. Nitrate was determined as the difference between nitrate+nitrite and nitrite measurements. Ammonia was measured using a citrate/tartrate buffer and phenol color reagent, catalyzed by hypochlorite and nitroprusside , followed by quantification with spectrophotometric determination of the phenol-ammonia complex at 630 nm. Phosphate samples reacted with antimo nytartrate and ammonium molybdate solution in sulfuric acidified solution, the resulting complex wasreduced by ascorbic acid to a deep blue dye, followed by quantification with spectrophotometric determination of the reduced antimony-phospho-molybdate complex at 880 nm. Silicate samples was acidified with sulfuric acid and reacted with ammonium molybdate solution, reduced by ascorbic acid to a blue dye with oxalic acid to remove phosphate interference , followed by quantification with spectrophotometric determination of the reduced molybdo-silicate complex at 810 nm. Methods used are accredited with expected detection limit of 0,04 µM for nitrite, 0,1 µM for nitrate, 0,3 µM for ammonia, 0,06 µM for Phosphate and 0,2 µM for silicate, with expected RSD between 4 and 7%for the individual nutrients. Certified reference materials (VKI type QC RW1 for ammonia, phosphate and nitrate) and internal reference materials for Nitrite and silicate was spiked at two levels to natural low nutrient seawater sample for quality assurance, recovering 91-109% of the spike for nitrite, nitrate, phosphate and silicate at with RSD% of 1 to 5%, and recovery of 84-91% for ammonia, with RSDs up to 15%. No corrections was performed on data the recoveries. Except for ammonia, all results was within the acceptance limits for accredited analysis. Analysis was performed over two runs, one with triplicates and then a fourth spare sample was included to investigate the ammonia instability, but it could not be determined if this was due to storage/transport or instrument The “.CSV” files of fully processed data contain data collected mainly in the North portion of the MAR in the Exclusive Economic Zone around the Azores.

This dataset was produced during the iMAR cruise “The Integrated assessment of the distribution of Vulnerable Marine Ecosystem along the Mid-Atlantic Ridge (MAR) in the Azores region”, that took place aboard the Research Vessel Pelagia of the Royal Netherlands Institute for Sea Research between May 19th and June 2nd 2021. The iMAR cruise aimed to evaluate the role of the MAR in shaping latitudinal and trans-Atlantic patterns in deep-sea biogeography, connectivity and assemblages of deep-sea megafauna. This expedition was funded by the SEA OCEANS program of Eurofleets+ and the H2020 European project iAtlantic, and was led by the University of the Azores (Portugal) in collaboration with the Hydrographic Institute and University of Porto (Portugal), the University of Aarhus (Denmark), the National Oceanography Center (United Kingdom), GEOMAR (Germany), the University Museum of Bergen (Norway), the PP Shirshov Institute of Oceanology (Russia), and the University of Vale do Itajaí (Brazil). ADCP data was collected at 34 stations during the iMAR cruise, mainly in the North portion of the MAR in the EEZ around the Azores (Table 1). This dataset contain the “.ENR” and another 9 file types with the same name structure but different extensions (.ENS; .ENX; .TXT; .LTA; .N1R; .N2R; .NMS; .STA; .VMO). VmDas Quick Start Guide: “.ENR” raw ADCP data file; “.ENS” ADCP data after having been screened for RSSI and correlation by VmDas; “.ENX” ADCP single-ping data (plus NAV) after having been bin-mapped, transformed to Earth coordinates, and screened for error velocity, vertical velocity, and false targets. “.LTA” ADCP (plus NAV) data that has been averaged using the long time period; “.N1R” and “.N2R” Raw NMEA data files; includes ADCP time stamps; “.N1R” extension is used for single-port NMEA data collection, or for GPS position data (Nav) in dual-port collection mode. The “.N2R” extension is used for Roll/Pitch/Heading (RPH) data collection when using two serial ports for NMEA data collection. “.NMS” Binary format NAV data file after having been screened and pre-averaged. “.STA” ADCP (plus NAV) data that has been averaged using the short time period; “.VMO” the option settings used for collecting the data (text file).

This dataset contain the metadata for all stations conducted during the iMAR cruise “The Integrated assessment of the distribution of Vulnerable Marine Ecosystem along the Mid-Atlantic Ridge (MAR) in the Azores region”, that took place aboard the Research Vessel Pelagia of the Royal Netherlands Institute for Sea Research between May 19th and June 2nd 2021. This expedition was funded by the SEA OCEANS program of Eurofleets+ and the H2020 European project iAtlantic, and was led by the University of the Azores (Portugal) in collaboration with the Hydrographic Institute and University of Porto (Portugal), the University of Aarhus (Denmark), the National Oceanography Center (United Kingdom), GEOMAR (Germany), the University Museum of Bergen (Norway), the PP Shirshov Institute of Oceanology (Russia), and the University of Vale do Itajaí (Brazil). Statistics: Cruise duration was 17 days, 2,500 km of transits, 6 areas visited, 5,500 km2 of mapped seabed (mainly in the North portion of the MAR in the EEZ around the Azores), 19 dives with the NIOZ video system that resulted in 54 hours of deep-sea images over 48 km of the seabed, 13 stations for the analysis of water mass properties and to collect sediments, which resulted in 380 samples for environmental DNA, 280 samples for nutrient analyses, 27 sediment samples for geological analyses, 24 for microplastic analyses, 10 samples for bacteriological, and 10 samples meiofauna analyses.

This dataset was produced during the iMAR cruise “The Integrated assessment of the distribution of Vulnerable Marine Ecosystem along the Mid-Atlantic Ridge (MAR) in the Azores region”, that took place aboard the Research Vessel Pelagia of the Royal Netherlands Institute for Sea Research between May 19th and June 2nd 2021. The iMAR cruise aimed to evaluate the role of the MAR in shaping latitudinal and trans-Atlantic patterns in deep-sea biogeography, connectivity and assemblages of deep-sea megafauna. This expedition was funded by the SEA OCEANS program of Eurofleets+ and the H2020 European project iAtlantic, and was led by the University of the Azores (Portugal) in collaboration with the Hydrographic Institute and University of Porto (Portugal), the University of Aarhus (Denmark), the National Oceanography Center (United Kingdom), GEOMAR (Germany), the University Museum of Bergen (Norway), the PP Shirshov Institute of Oceanology (Russia), and the University of Vale do Itajaí (Brazil). Vertical CTD Seabird SBE 32 /Rosette profiles were conducted at 19 stations to generate Sound Velocity Profiles (Table 1), mainly in the North portion of the MAR in the Exclusive Economic Zone around the Azores. The “.cnv” files contain the sound velocity data binned to 1 m depth intervals using the “bin average”.

This dataset was produced during the iMAR cruise “The Integrated assessment of the distribution of Vulnerable Marine Ecosystem along the Mid-Atlantic Ridge (MAR) in the Azores region”, that took place aboard the Research Vessel Pelagia of the Royal Netherlands Institute for Sea Research between May 18th and June 2nd 2021. The iMAR cruise aimed to evaluate the role of the MAR in shaping latitudinal and trans-Atlantic patterns in deep-sea biogeography, connectivity and assemblages of deep-sea megafauna. This expedition was funded by the SEA OCEANS program of Eurofleets+ and the H2020 European project iAtlantic, and was led by the University of the Azores (Portugal) in collaboration with the Hydrographic Institute and University of Porto (Portugal), the University of Aarhus (Denmark), the National Oceanography Center (United Kingdom), GEOMAR (Germany), the University Museum of Bergen (Norway), the PP Shirshov Institute of Oceanology (Russia), and the University of Vale do Itajaí (Brazil). Vertical CTD/Rosette profiles were conducted with the CTD Seabird SBE 32 at 19 stations to measure physical and chemical seawater properties that characterize the dominant water masses described for the North MAR region of the Azores (Table 1). The “.CNV” files of fully processed data contain data of twenty-two parameters interpolated at 1-meter bins, (Table 2), mainly in the North portion of the MAR in the Exclusive Economic Zone around the Azores.

Description: We developed predictive distribution models of deep-sea elasmobranchs for up to 2000 m depth in the Azores EEZ and neighboring seamounts, from approximately 33°N to 43°N and 20°W to 36°W. Georeferenced presence, absence, and abundance data were obtained from scientific surveys and commercial operations reporting at least one deep-sea elasmobranch capture. A 20-year 'survey dataset' (1996-2017) was compiled from annual scientific demersal surveys using two types of bottom longlines (types LLA and LLB), and an 'observer dataset' (2004-2018) from observer programs covering commercial fisheries operations using bottom longline (similar to type LLA) and vertical handline ('gorazeira'). We used the most ecologically relevant candidate environmental predictors for explaining the spatial distribution of deep-sea elasmobranch in the Azores: depth, slope, northness, eastness, Bathymetric Position Index (BPI), nitrates, and near bottom currents. We merged existing multibeam data for the Azores EEZ with bathymetry data extracted from EMODNET (EMODnet Bathymetry Consortium 2018) to calculate depth values (down to 2000m). All variables were projected with the Albers equal-area conical projection centered in the middle of the study area and were rescaled using bilinear interpolation to a final grid cell resolution of 1.12 x1.12 km (i.e., 0.012°). Slope, northness, and eastness were computed from the depth raster using the function terrain in the R package raster. BPI was derived from the rescaled depth with an inner radius of 3 and an outer radius of 25 grid cells using the Benthic Terrain Model 3.0 tool in ArcGIS 10.1. Nitrates were extracted from Amorim et al. (2017). Near-bottom current speed (m·s-1) average values were based on a MOHID hydrodynamic model application (Viegas et al., 2018) with an original resolution of 0.054°. Besides the environmental variables, we also included three operational predictors in the analysis: year, fishing effort (number of hooks) and gear type (longline LLA and LLB, and gorazeira).

This dataset was collected during the iMAR cruise “The Integrated assessment of the distribution of Vulnerable Marine Ecosystem along the Mid-Atlantic Ridge (MAR) in the Azores region”, that took place aboard the Research Vessel Pelagia of the Royal Netherlands Institute for Sea Research (NIOZ) between May 19th and June 2nd 2021. The iMAR cruise aimed to evaluate the role of the MAR in shaping latitudinal and trans-Atlantic patterns in deep-sea biogeography, connectivity and assemblages of deep-sea megafauna. This expedition was funded by the SEA OCEANS program of Eurofleets+ and the H2020 European project iAtlantic, and was led by the University of the Azores (Portugal) in collaboration with the Hydrographic Institute and University of Porto (Portugal), the University of Aarhus (Denmark), the National Oceanography Center (United Kingdom), GEOMAR (Germany), the University Museum of Bergen (Norway), the PP Shirshov Institute of Oceanology (Russia), and the University of Vale do Itajaí (Brazil). The deep-sea benthic communities were mapped using the NIOZ towed camera system. The Hopper system generated a series of high-definition video transects in each area explored, starting from the deepest point (set at 1,200 m approx.) and moving upwards towards the seamount or ridge summit (700 m to 300 m depth). During the iMAR cruise, 22 stations for Hopper video transects were performed (Table 1), mainly in the North portion of the MAR inside the Exclusive Economic Zone around the Azores, which produced approximately 54 hours of bottom time, along 48 km of seafloor.

It is increasingly recognised that deep-sea mining of seafloor massive sulphides (SMS) could become an important source of mineral resources. These operations will remove the targeted substrate and produce potentially sediment toxic plumes from in situ seabed excavation and from the return water pumped back down to the seafloor. However, the spatial extent of the impacts of deep-sea mining plumes is still uncertain because few field experiments and models of plumes dispersion have been conducted. Morato et al. (2022) used three-dimensional hydrodynamic models of the Azores region together with a theoretical commercial mining operation of polymetallic SMS to simulate the potential dispersal of sediment plumes originating from different phases of mining operations and to assess the magnitude of potential impacts. The areas used in the modelling work were (from North to South): Cavala seamount (38.265, -30.710), Lucky Strike Hole (37.503, -31.955), Menez Hom (37.109, -32.618), Famous (37.001, -33.039), Saldanha (36.658, -33.420), and Rainbow (36.262 -33.824). The datasets published here contain all the model outputs, namely for 1) the in situ excavation sediment plume, 2) the return water discharge plume, and 3) the return sediments discharge plume:1) The concentration of solids and of the discharge water in each horizontal 2-dimensional space cell is calculated as the maximum concentration in the 50 vertical layers of each 2-dimensional cell, for each output time step (3 hours), averaged over all time steps during each trimester and during a 12-months simulation.1.1) Concentration of sediments produced during the in situ excavation sediment plume calculated as the maximum concentration in the 50 vertical layers of each 2-dimensional cell, for each output time step (3 hours), averaged over all time steps during a 12-months simulation. Sediments were composed of six classes of different particle diameter (0-10 μm, 10-50 μm, 50-100 μm, 100-200 μm, 200-2,000 μm, and >2,000 μm), an average particle density of 3,780 kg·m-3, and resultant settling velocities ranging from 75.1 cm·s-1 to 0.002 cm·s-1.1.2) Concentration of return water discharge plume (shown in dilution folds) in six study areas calculated as the maximum concentration in the 50 vertical layers of each 2-dimensional cell, for each output time step (3 hours), averaged over all time steps during a 12-months simulation and assuming a control temperature as the annual minimum temperature of each location (T1). The salinity of discharge was calculated assuming the MOHID salinity of 83.3% surface water and 16.7% of seafloor water.1.3) Concentration of sediments in the return sediment discharge plume, calculated as the maximum concentration in the 50 vertical layers of each 2-dimensional cell, for each output time step (3 hours), averaged over all time steps during a 12-months simulation. The average particle diameter was assumed to be 4 µm with an average particle density of 3,780 kg·m-3 and a resultant settling velocity of 0.002 cm·s-1.2) The proportion of simulated time (temporal frequency) that a specific 2-dimensional space contained plume concentrations higher than the adopted thresholds; 1.2 mg·L-1 for sediment solids and 5,000 fold dilution for discharge water. Those cells whose temporal frequency above the thresholds was greater than 50%, i.e. 6 months out of 12 months, were considered as cells with persistent plumes.2.1) Proportion of simulated time (temporal frequency) that a specific a 2-dimensional space cell, in six study areas, contained in situ excavation sediment plume above a 1.2 mg·L-1 concentration threshold, during a 12-months simulation, assuming six classes of particle diameter (0-10 μm, 10-50 μm, 50-100 μm, 100-200 μm, 200-2,000 μm, and >2,000 μm), an average particle density of 3,780 kg·m-3, and resultant settling velocities ranging from 75.1 cm·s-1 to 0.002 cm·s-1.2.2) Proportion of simulated time (temporal frequency) that a specific 2-dimensional space, in six study areas, contained return water discharge plume concentrations higher than the adopted thresholds (i.e., 5,000 fold dilution), during a 12-months simulation and assuming a control temperature as the annual minimum temperature of each location (T1). The salinity of discharge was calculated assuming the MOHID salinity of 83.3% surface water and 16.7% of seafloor water.2.3) Proportion of simulated time (temporal frequency) that a specific 2-dimensional space cell, in six study areas, contained return sediments discharge plume above a 1.2 mg·L-1 concentration threshold, during a 12-months simulation, assuming an average particle diameter of 4 µm, an average particle density of 3,780 kg·m-3, and a resultant settling velocity of 0.002 cm·s-1.3) In addition to the thresholds and targets described above, the datasets also present the model results for Cavala seamount and Lucky Strike Hole against other thresholds: 5 mg·L-1, 10 mg·L-1 and 25 mg·L-1 for sediments and 1,000, 600, 300 and 200 fold dilution for discharge water.4) Seasonal variations in the model outputs for plumes dispersal are also presented for Cavala seamount and Lucky Strike Hole by computing the probability of concentration above thresholds for four periods of three months (January-March, April-June, July-September, and October-December). In these scenarios, the model run duration was approximately 90 days.5) The sediment thickness of the settled sediments from the discharge sediment and excavation.5.1) Bottom thickness of settled sediments produced during the in situ excavation sediment plume assuming six classes of particle diameter (0-10 μm, 10-50 μm, 50-100 μm, 100-200 μm, 200-2,000 μm, and >2,000 μm), an average particle density of 3,780 kg·m-3, and resultant settling velocities ranging from 75.1 cm·s-1 to 0.002 cm·s-1. The duration of the simulation is one year.5.2) Bottom thickness of settled sediments from the return sediment discharge plume modelled assuming an average particle diameter of 4 µm, an average particle density of 3,780 kg·m-3, and a resultant settling velocity of 0.002 cm·s-1. The duration of the simulation is one year.

The objective of this study is to determine the effects of ocean acidification (OA) on the survival, development and swimming behaviour of embryos of the deep-sea coral Desmophyllum pertusum (syn. Lophelia pertusa). Upon spawning, fertilized embryos were collected and exposed to two pCO2 treatments corresponding to present pCO2 conditions (400 ppm) and future pCO2 conditions predicted under scenario IPCC RCP8.5 for the end of the century (1000 ppm). We monitored survival daily and we measured swimming velocity on day 9 after spawning. Temperature and pH were measured every 24h, salinity was measured every other day, and water samples were collected during the first and last day of the experiment to determine total alkalinity (TA). This dataset includes data on the effects of ocean acidification on swimming velocity of larvae of the deep-sea coral Desmophyllum pertusum. Embryos were exposed to two acidification (pCO2) treatments: present pCO2 conditions (400 ppm) and future pCO2 conditions predicted under RCP8.5 for the end of the century (1000 ppm). After rearing the embryos in the respective treatments for nine days, we recorded the swimming behaviour of larvae with a video camera. Videos were analyzed with manual particle tracking, and here we report the swimming velocity and total traveled distance of larvae in each experimental treatment.

Includes data estimate of survival.

Contains data on larval behaviour.

Includes data on the embryo development of the species. Embryos/larvae were monitored (counted) and classified to developmental stages every 3-4 hours until the planula stage and every 2-3 days afterwards.

Contains data on swimming velocity and behaviour.

The study focuses on the early life stages of the species Dentomuricea aff. meteor, a common deep-sea octocoral in the Azores. The objective was to describe the embryo and larval development, survival and swimming behaviour of early life stages of the target species, under two temperature regimes, corresponding to the minimum and maximum temperatures in its natural environment during the spawning season (13°C and 15°C). Embryo and larval development were monitored closely and revealed faster developmental rates under 15°C. Survival counts were performed throughout embryo and larval development, but were not statistically different between temperatures. Moreover, swimming behaviour was assessed by means of video recordings, revealing a higher larval swimming speed at 15°C. Additional data on larval behaviour are provided, including settlement and metamorphosis rates which were low for both temperatures. Our results showcase how small temperature fluctuations can affect embryo and larval characteristics, potentially impacting larval dispersal and success.

In 2014, the continental shelf and submarine canyon off Cap de Creus (NW Mediterranean) were included in the Site of Community Importance (SCI) “South-West Gulf of Lions canyons system” of the Natura 2000 Network of protected areas. Before the declaration of the SCI (2007-2103), 60 underwater video transects were performed in the area by means of ROVs and a manned submersible, covering more than 30 km of seafloor. Based on the annotation of the video images, we identified the main invertebrate megabenthic communities dwelling from the shelf (70 m depth) down to the bottom of the canyon head (400 m depth). The results of the multivariate analyses indicated that this marine area hosted several benthic communities dominated by suspension- and filter-feeding species, including octocoral gardens, soft-coral assemblages, crinoid fields, sponge grounds and cold-water corals. This dataset includes (1) the geographical location of the benthic communities identified in the video footage, as determined by the clustering analysis, (2) the intra-community diversity associated to the benthic communities, provided as the number of megafauna species identified in each sampling unit and the exponential of Shannon, and (3) the spatial distribution of the benthic communities mapped by means of the Random Forest classification algorithm. This dataset is related to the article “Diversity, structure and spatial distribution of megabenthic communities in Cap de Creus continental shelf and submarine canyon (NW Mediterranean)” submitted to Progress in Oceanography by Dominguez-Carrió et al., which contains further information on how the data were obtained and processed.

Annotation of Paragorgia johnsoni Gray, 1862 colonies from underwater video footage recorded during the Blue Azores 2018 Expedition with the ROV Luso onboard the NRP Almirante Gago Coutinho, Station 57, Dive 15 (June 23^rd, 2018). The images correspond to the octocoral garden discovered between 545 and 595 m depth on the slopes of a small ridge-like structure located on the Mid-Atlantic Ridge, in the Azores region.

We used environmental niche modelling along with the best available species occurrence data and environmental parameters to model habitat suitability for key cold-water coral and commercially important deep-sea fish species under present-day (1951-2000) environmental conditions and to forecast changes under severe, high emissions future (2081-2100) climate projections (RCP8.5 scenario) for the North Atlantic Ocean (from 18°N to 76°N and 36°E to 98°W). This dataset contains a set of terrain (static in time) and environmental (dynamic in time) variables were used as candidate predictors of present-day (1951-2000) distribution and to forecast future (2081-2100) changes. All predictor variables were projected with the Albers equal-area conical projection centred in the middle of the study area. The terrain variable depth was extracted from a bathymetry grid built from two data sources: the EMODnet Digital Terrain Model (EMODnet, 2018) and the General Bathymetric Chart of the Oceans (GEBCO 2014; Weatherall et al., 2015). Slope (in degrees) was derived from the final bathymetry grid using the Raster package in R (Hijmans, 2016) and the Bathymetric Position Index (BPI) was computed using the Benthic Terrain Model 3.0 tool in ArcGIS 10.1 with an inner radius of 3 and an outer radius of 25 grid cells. In order to avoid extreme values, BPI was standardized using the scale function from the Raster package. Environmental variables of present-day and future conditions, including particulate organic carbon (POC) flux at 100-m depth (epc100, mg C m-2 d-1), bottom water dissolved oxygen concentration (µmol kg-1), pH, and potential temperature (°K) were downloaded from the Earth System Grid Federation (ESGF) Peer-to-Peer (P2P) enterprise system. The epc100 was converted to export POC flux at the seafloor using the Martin curve (Martin, Knauer, Karl, & Broenkow, 1987) following the equation: epc = epc100*(water depth/export depth)-0.858, and setting the export depth to 100 m. Near seafloor aragonite (Ωar) and calcite (Ωcal) saturation were also used as candidate predictors for habitat suitability of cold-water coral species. These saturation states were computed by dividing the bottom water carbonate ion concentration (mol m-3) by the bottom water carbonate ion concentration (mol m-3) for seawater in equilibrium with pure aragonite and calcite. Yearly means of these parameters were calculated for the periods 1951-2000 (historical simulation) and 2081-2100 (RCP8.5 or business-as-usual scenario) using the average values obtained from the Geophysical Fluid Dynamics Laboratory's ESM 2G model (GFDL-ESM-2G; Dunne et al., 2012), the Institut Pierre Simon Laplace's CM6-MR model (IPSL-CM5A-MR; Dufresne et al., 2013) and Max Planck Institute's ESM-MR model (MPI-ESM-MR; Giorgetta et al., 2013) within the Coupled Models Intercomparison Project Phase 5 (CMIP5) for each grid cell of the present study area.

Obtaining a comprehensive knowledge of the spatial variation of deep-sea benthic ecosystems is essential for conservation and management purposes. Here we assembled publicly available information on the positions of vulnerable marine ecosystem indicator species from public databases (OBIS, NOAA and ICES), the published literature and from focused efforts from the Logachev Mounds (NE Atlantic), Tropic Seamount (NE tropical Atlantic) and Bermuda for depths below 200 m. Taxa included hexacorals, octocorals, hydroids, sponges, hydrothermal vents associated species (bivalves, decapods), crinoids and xenophyophores.

This data is showing the outcomes of the analysis done by ATLAS researchers on the environmental status of nine deep-sea areas in the northeast Atlantic. These results are part of the ATLAS work facilitating the implementation of the European Commission's Marine Strategy Framework Directive in the deep waters of the North Atlantic. The nine study areas that were examined are: 1) LoVe Ocean Observatory, 2) Faroe-Shetland Channel, 3) Reykjanes Ridge, 4) Rockall Bank, 5) Mingulay Reef Complex, 6) Porcupine Seabight, 7) Bay of Biscay, 8) Azores, 9) Gulf of Cádiz. The analyses were carried out using the Nested Environmental status Assessment Tool (NEAT). The environmental status outcomes are shown for the total study area, the designated spatial assessment units (SAUs), the ecosystem components ("Benthic invertebrates", "Fish", "Benthos") and the habitats ("Aggregations of L. pertusa & M. oculata on soft sediments", "Aggregations of sea pens & alcyonaceans on soft sediments", "Aggregations of L. pertusa & M. oculata on hard substrates", "Aggregations of Antipatharians and alcyonaceans on hard substrates", "Benthic", "Rocky", "Sedimentary").

We applied the International Council for the Exploration of the Sea (ICES) multi criteria assessment (MCA) method for identifying VMEs in the North-East Atlantic (ICES, 2016a,b; Morato et al., 2018) from ATLAS VME database to provide the first North Atlantic Ocean basin-scale VME assessment. This MCA is a taxa-dependent spatial method that incorporates the fact that not all VME indicators have the same vulnerability to human impacts, and thus should not be weighted equally. By including a measure of the confidence associated with each VME record, this methodology also considers some of the uncertainties associated with the sampling methodologies, the reported taxonomy, and data quality issues. Equally important, this dataset highlights areas in the North Atlantic that have been poorly sampled and that require further attention. Finally, this methodology also allows for the evaluation and comparison of the VME likelihood with spatial fisheries data that may directly generate significant adverse impacts on VMEs. In the data report, we made the “North Atlantic basin-scale VME index dataset” publicly, thus allowing its consultation and use by scientists, managers, or other relevant stakeholders.

Swiftia phaeton, a new species, is described for Mauritania where it is endemic at the upper bathyal. This azooxanthellate octocoral is distinctive from congeneric species in the NE Atlantic and Mediterranean Sea by the dark red coloration of the colonies and polyps, the presence of a layer of rod sclerites on top of the calyces and different sizes of polyps and sclerites. Coral gardens dominated by a species of the genus Swiftia Duchassaing & Michelotti, 1864 were filmed for the first time it the southern NE Atlantic Ocean. The extensive Swiftia phaeton sp. nov. dominated habitats were recorded during the Phaeton expedition onboard Maria S. Merian in 2010 at the Mauritanian Slope between 20°24N and 17°54N in 470 - 640 m depth, co-occurring with the framework-forming scleractinians Lophelia pertusa (Linnaeus, 1758) and Madrepora oculata (Linnaeus, 1758). ROV video annotation based on size and density distribution of Swiftia enabled the characterization of the new biotope.

Deep-water octocorals form rich communities known as "coral gardens", considered priority habitats for protection. Despite their importance as habitat-builders, our knowledge on their reproductive biology is rarely available. The objective of this study was to collect data on reproductive parameters of two common habitat-forming octocorals in depths between 200 and 600: Dentomuricea aff. meteor and Viminella flagellum. Specimens were collected during 2010 and 2011 as by-catch from deep-sea long-line fisheries and scientific cruises and were histologically processed. Both species were found to be gonochoric, broadcast spawning with continuous gamete presence and overlapping reproductive cycles. The produced data include gamete presence, gamete size and polyp fecundity across different months during the study period.

Benthic suspension feeders have developed a variety of feeding strategies and food availability has often proven to be a key factor explaining their occurrence and distribution. The feeding biology of coral species has been the target of an increasing number of studies, however most of them focus on Scleractinia and Octocorallia, while information for Antipatharia is very scarce. The present study focused on Antipathella wollastoni, a common habitat-forming antipatharian in the Azores Archipelago, forming dense black coral forests between 20 and 150 meters. The objective of the study was to investigate the food preferences of the target species upon availability of different isotopically enriched food substrates and determine its ability to capture zooplankton prey under different flow speeds. The species was able to utilize different food sources including live phytoplankton, live zooplankton and Dissolved Organic Matter (DOM), indicating the ability to exploit seasonally available food sources. However ingestion of zooplankton enhanced Carbon (C) and Nitrogen (N) incorporation in coral tissue and metabolic activity, highlighting the importance of zooplankton prey for vital physiological processes such as growth and reproduction. The species displayed a high capacity to capture zooplankton prey over different flow rates, however capture rates were higher under 4 cm s-1, highlighting the ability of A. wollastoni to exploit high quantities of shortly available prey.

Coral gardens are considered to be hotspots of biodiversity and ecosystem functioning, due to the important structural and biogeochemical role of cold-water coral (CWC) species. Despite an increase in studies on deep reef-forming species, information on cold-water octocoral species is still very scarce. The present study focused on the feeding biology of two habitat-forming octocoral species typically encountered in seamounts in the Azores between 200 and 600m of depth: Dentomuricea aff. meteor and Viminella flagellum. We used an experimental approach aiming at determining the ability of the species to utilize different food sources including live phytoplankton (the diatom Chaetoceros calcitrans), Dissolved Organic Carbon (DOC) and live zooplankton (the rotifer Branchionus plicatilis). Food sources were isotopically enriched with tracers (13C, 15N) which allowed to trace the ingested food in different physiological processes, such as tissue incorporation, Dissolved Inorganic Carbon (DIC) respiration and excretion of Particulate Organic Carbon (POC) and Particulate Organic Nitrogen (PON).

Sampaio, Íris; Beuck, Lydia; Carreiro-Silva, Marina; Menezes, Gui M; Freiwald, André (2020): Video annotation of Swiftia phaeton during the MSM16 Cruise in 2010 at the Mauritanian Slope [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.910892, In: Sampaio, Í et al. (2020): Morphological measurements and video annotation of the new octocoral Swiftia phaeton sp. nov. during the cruise MSM 16-3 Phaeton in 2010 off the Mauritanian Slope [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.910893

The majority of octocoral species are found in waters deeper than 50m where they create three-dimensional and highly heterogenous habitats known as coral gardens. The Azores Archipelago is an octocoral biodiversity hotspot and coral gardens are one of the most prominent deep-sea communities encountered regionally. Although food availability and flow have been recognized as key factors in determining the dynamics of suspension feeder communities, very little information exists on how flow affects the feeding capacity of deep octocoral species. The study focused on two common habitat-forming octocoral species in the Azores, Dentomuricea meteor and Viminella flagellum, aiming at determining their ability to capture zooplankton prey under variable flow velocities. The rotifer Branchionus plicatilis was used as prey, while three flow velocities were established in recirculating 13L flumes: 3 cm/s, 6 cm/s and 9 cm/s. Both species efficiently captured zooplankton prey. Capture rates were lower under 3 cm/s, however no difference was detected between 6 and 9 cm/s. Dentomuricea meteor reached higher capture rates per polyp than V.flagellum, possibly due to their differences in polyp size and density.

Sampaio, Íris; Beuck, Lydia; Carreiro-Silva, Marina; Menezes, Gui M; Freiwald, André (2020): Morphological measures of colonies and polyps of the new octocoral species Swiftia phaeton during the MSM16 Cruise in 2010 at the Mauritanian Slope [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.910888, In: Sampaio, Í et al. (2020): Morphological measurements and video annotation of the new octocoral Swiftia phaeton sp. nov. during the cruise MSM 16-3 Phaeton in 2010 off the Mauritanian Slope [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.910893

Sampaio, Íris; Beuck, Lydia; Carreiro-Silva, Marina; Menezes, Gui M; Freiwald, André (2020): Morphological measures of sclerome of the new octocoral species Swiftia phaeton during the MSM16 Cruise in 2010 at the Mauritanian Slope [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.910890, In: Sampaio, Í et al. (2020): Morphological measurements and video annotation of the new octocoral Swiftia phaeton sp. nov. during the cruise MSM 16-3 Phaeton in 2010 off the Mauritanian Slope [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.910893

Sites with naturally high CO2 conditions provide unique opportunities to forecast the vulnerability of coastal ecosystems to ocean acidification, by studying the biological responses and potential adaptations to this increased environmental variability. In this study, we investigated the bivalve Ervilia castanea in coastal sandy sediments at reference sites and at volcanic CO2 seeps off the Azores, where the pH of bottom waters ranged from average oceanic levels of 8.2, along gradients, down to 6.81, in carbonated seawater at the seeps. The bivalve population structure changed markedly at the seeps. Large individuals became less abundant as seawater CO2 levels rose and were completely absent from the most acidified sites. In contrast, small bivalves were most abundant at the CO2 seeps. We propose that larvae can settle and initially live in high abundances under elevated CO2 levels, but that high rates of post-settlement dispersal and/or mortality occur. Ervilia castanea were susceptible to elevated CO2 levels and these effects were consistently associated with lower food supplies. This raises concerns about the effects of ocean acidification on the brood stock of this species and other bivalve molluscs with similar life history traits.

We used environmental niche modelling along with the best available species occurrence data and environmental parameters to model habitat suitability for key cold-water coral and commercially important deep-sea fish species under present-day (1951-2000) environmental conditions and to forecast changes under severe, high emissions future (2081-2100) climate projections (RCP8.5 scenario) for the North Atlantic Ocean (from 18°N to 76°N and 36°E to 98°W). The VME indicator taxa included Lophelia pertusa , Madrepora oculata, Desmophyllum dianthus, Acanela arbuscula, Acanthogorgia armata, and Paragorgia arborea. The six deep-sea fish species selected were: Coryphaenoides rupestris, Gadus morhua, blackbelly Helicolenus dactylopterus, Hippoglossoides platessoides, Reinhardtius hippoglossoides, and Sebastes mentella. We used an ensemble modelling approach employing three widely-used modelling methods: the Maxent maximum entropy model, Generalized Additive Models, and Random Forest. This dataset contains: 1) Predicted habitat suitability index under present-day (1951-2000) and future (2081-2100; RCP8.5) environmental conditions for twelve deep-sea species in the North Atlantic Ocean, using an ensemble modelling approach. 2) Climate-induced changes in the suitable habitat of twelve deep-sea species in the North Atlantic Ocean, as determined by binary maps built with an ensemble modelling approach and the 10-percentile training presence logistic (10th percentile) threshold. 3) Forecasted present-day suitable habitat loss (value=-1), gain (value=1), and acting as climate refugia (value=2) areas under future (2081-2100; RCP8.5) environmental conditions for twelve deep-sea species in the North Atlantic Ocean. Areas were identified from binary maps built with an ensemble modelling approach and two thresholds: 10-percentile training presence logistic threshold (10th percentile) and maximum sensitivity and specificity (MSS). Refugia areas are those areas predicted as suitable both under present-day and future conditions. All predictions were projected with the Albers equal-area conical projection centred in the middle of the study area. The grid cell resolution is of 3x3 km.

Herein we report the respiration rates (O2 consumption) of the cold-water coral Viminella flagellum exposed to acute Cu concentrations. In a lab experiment, sixty nubbins of V. flagellum were distributed in six aquaria of 8 L (ten nubbins per aquarium) of each Cu solution (0 (control); 60; 150; 250; 450 and 600 μg/L) for 96 h. After this period, four nubbins from each Cu treatment, selected randomly, were incubated individually for 6 h in glass chambers filled with ca. 110 mL of 0.2 μm pre-filtered seawater, with the respective Cu dilutions (4 chambers per Cu concentration). The incubation period was set to 6 h to record changes in O2 consumption without exposing corals to oxygen levels below 80 % (air saturation, a.s.). During the incubation period, dissolved O2 (μmol/L) depletion rates were recorded every 30 min and corrected by the corresponding rates/variations in chambers without corals. Coral respiration rates were normalized to the coral surface area and time. Results are presented by µmol of O2 consumption per m2 per h.

Knowledge on Azorean octocorals is still dispersed in several taxonomical papers and monographs. Moreover it is hard to find and written in different languages representing a challenge for zoological nomenclature and taxonomic studies. Taxonomic literature about octocorals (orders Alcyonacea and Pennatulacea) inhabiting the Azores marine waters was compiled from the 19th century onwards. Papers and monographs were analysed in order to calculate the taxonomic effort applied to different ranks of Octocorallia in the region. Moreover, the number of species given to the Azores was presented within each family, suborder and order of Octocorallia. The dataset compiles literature references and species richness distributed within Octocorallia ranks. Both are essential for future taxonomical, ecological, molecular and conservation studies about Azorean Cold-water octocorals.

Obtaining a comprehensive knowledge of the spatial and temporal variations of the environmental factors characterizing the Azores region is essential for conservation and management purposes. Although many studies are available for the region, there is a need for a general overview of the best available information. Here, we assembled a comprehensive collection of environmental data for this region. Data sources used in this study included remote sensing oceanographic data for 2003?2013 (sea surface temperature, chlorophyll-a concentration, particulate inorganic carbon (PIC), and particulate organic carbon (POC)), derived oceanographic data (primary productivity and North Atlantic oscillation index) for 2003?2013, and in situ data (temperature, salinity, oxygen, phosphate, nitrate and silicate) obtained from the World Ocean Atlas 2013.

Recent studies carried out in coral reef settings or under controlled conditions showed that rising aqueous pCO2 (pH ≥ 7.8 – 7.9, and a saturation state of carbonate minerals > 1) stimulates the growth of reef microboring or euendolithic phototrophs, especially microalgae, and therefore, enhance rates of biogenic dissolution of carbonates. Those micro-organisms play a major role in reef bioerosion and coral reef functioning. In temperate-cold carbonate ecosystems, carbonate dissolution by euendolithic microflora has never been investigated under natural ocean acidification conditions. We thus realized two experiments to investigate the effects of low pH (and saturation states) on early natural microboring communities colonizing various carbonates and their associated rates of biogenic dissolution. One was carried out at Ischia (Italy) with mollusk shells exposed at two CO2 vents (pH < 7.5) vs an ambient site (pH ~ 8) during six months. The other one was realized at Faial (Azores) with various carbonate substrates (both aragonite and calcite) at one CO2 vent (pH ~ 7.4) vs an ambient site (pH ~ 8) over 45 days. Here we provide the data which allowed calculating rates of carbonate biogenic dissolution at all studied sites; i.e. the depth of penetration of euendolithic filaments into carbonates and the % of surface area of substrate colonized by microborers (bioeroded surface area). Rates of biogenic dissolution per site and per location are also provided, as well as environmental data collected at Faial (those collected at Ischia are published elsewhere). A total of 5 excel files is thus provided.

Current European legislation such as the Marine Strategy Framework Directive (MSFD; 2008/56/EC) has highlighted the need for accurate maps on the geomorphology of Europe's maritime territory. Such information is notably essential for the production of habitat maps and cumulative impact assessments of human activities (Halpern et al., 2008) necessary for marine spatial planning initiatives (Gilliland and Laffoley, 2008) and assessments of the representativity/sufficiency of marine protected areas networks like Natura 2000. Broadscale satellite bathymetry presently allows the identification of all prominent geomorphic structures present on the seafloor with a high grade of accuracy. However, these datasets and maps still need to be more widely disseminated in the scientific community.In this contribution, we provide an inventory of some important datasets related to the physical characteristics of the seafloor surrounding the Azores Archipelago. The objective is to ensure that our compilation is readily available for any researchers interested in developing species distribution models, or for the management and conservation of natural resources in the region.

We report the results of an aquaria-based experiment testing the effects of suspended particles generated during potential mining activities, on a common habitat-building coral species in the Azores, Dentomuricea aff. meteor. Coral fragments were maintained in 10-L aquaria and exposed to three experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) control conditions (no added sediments); (2) suspended polymetallic sulphide (PMS) particles; (3) suspended quartz particles. The concentration of suspended PMS and quartz particles in each treatment was measured during an exposure period of 4 hours. Suspended particle concentrations were measured one minute after particle addition, and then at intervals of 5, 15, 30 minutes, 1 hour, 2 hours and 4 hours after particle addition in the PMS and quartz particle treatments and in control aquaria with no particle addition.

We report the results of an aquaria-based experiment testing the effects of suspended particles generated during potential mining activities, on a common habitat-building coral species in the Azores, Dentomuricea aff. meteor. Coral fragments were maintained in 10-L aquaria and exposed to three experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) control conditions (no added sediments); (2) suspended polymetallic sulphide (PMS) particles; (3) suspended quartz particles. Integrated measurements of coral respiration and ammonium release rates were carried out by closed-chamber incubation in cylindrical acrylic chambers on days 0, 13 and 27 of the experiment using an oxygen meter Fibox4 with a PSt3 sensor (PreSens, Germany). Coral respiration and excretion rates were normalized to the coral skeletal surface area.

We report the results of an aquaria-based experiment testing the effects of suspended particles generated during potential mining activities, on a common habitat-building coral species in the Azores, Dentomuricea aff. meteor. Coral fragments were maintained in 10-L aquaria and exposed to three experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) control conditions (no added sediments); (2) suspended polymetallic sulphide (PMS) particles; (3) suspended quartz particles. Seawater physical-chemical parameters were measured daily in each aquarium. Seawater salinity was measured with a S30 SevenEasy™ conductivity meter, pH and temperature with a glass electrode (Crison pH 25+), and oxygen with a Fibox4 (PreSens) with a Oxygen Dipping Probe DP-PSt3. Seawater samples for inorganic nutrient analyses were collected on times 0 (immediately before the start of the experiment), and once a week on days 6, 13, 20 and 27 of the experiment and determined using a colorimetric autoanalyzer Sanplus with segmented flow.

We report the results of an aquaria-based experiment testing the effects of suspended particles generated during potential mining activities, on a common habitat-building coral species in the Azores, Dentomuricea aff. meteor. Coral fragments were maintained in 10-L aquaria and exposed to three experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) control conditions (no added sediments); (2) suspended polymetallic sulphide (PMS) particles; (3) suspended quartz particles. Trace elements (Co, Cu, Mn) released from the resuspension of PMS particles to the water column in each aquaria were determined using passive sampling (DGT® Research Ltd) coupled with inductively coupled plasma mass spectrometry (ICPMS). DGT-holders were deployed in all aquaria and replaced every week (days 6, 13, 20, 27).

We report the results of an aquaria-based experiment testing the effects of suspended particles generated during potential mining activities, on a common habitat-building coral species in the Azores, Dentomuricea aff. meteor. Coral fragments were maintained in 10-L aquaria and exposed to three experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) control conditions (no added sediments); (2) suspended polymetallic sulphide (PMS) particles; (3) suspended quartz particles. Trace elements in the tissues and skeletons of corals at the end of the experiment were quantified by a quadrupole ICPMS (Thermo Elemental, X-Series). The metal concentrations in coral tissues are given in microgram per gram of dry weight tissue (μg g-1; dw).

We report the results of an aquaria-based experiment testing the effects of suspended particles generated during potential mining activities, on a common habitat-building coral species in the Azores, Dentomuricea aff. meteor. Coral fragments were maintained in 10-L aquaria and exposed to three experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) control conditions (no added sediments); (2) suspended polymetallic sulphide (PMS) particles; (3) suspended quartz particles. Antioxidant stress related biomarkers (glutathione S−transferase, superoxide dismutase, catalase, malondialdehyde) in D. aff. meteor tissues were used to evaluate the degree of cellular stress induced by exposure to PMS and quartz particles at times 0 and 13 days in all treatments and from the control and quartz treatments also at time 27 days of the experiment.

We report the results of an aquaria-based experiment testing the effects of suspended particles generated during potential mining activities, on a common habitat-building coral species in the Azores, Dentomuricea aff. meteor. Coral fragments were maintained in 10-L aquaria and exposed to three experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) control conditions (no added sediments); (2) suspended polymetallic sulphide (PMS) particles; (3) suspended quartz particles. Gene expression profiles in D. aff. meteor were used to evaluate the physiological pathways involved in the response to exposure to PMS and quartz particles. Coral fragments were collected from each treatment at times 0, 3, and 13 days and for the control and quartz treatments also at time 27 days. The study targeted genes involved in cellular stress and antioxidant reaction system (heat shock protein, superoxide dismutase, ferritin), cell structure/integrity (α-carbonic anhydrase, receptor-type protein tyrosine phosphatase) and immune responses (toll-like receptor, lysozyme, rel homology domain, ferritin).

We report the results of an aquaria-based experiment testing the effects of suspended particles generated during potential mining activities, on a common habitat-building coral species in the Azores, Dentomuricea aff. meteor. Corals were collected from the summit of Condor Seamount (Azores, NE Atlantic) at depths between 185-210 m in August 2014. Coral fragments were maintained in 10-L aquaria and exposed to three experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) control conditions (no added sediments); (2) suspended polymetallic sulphide (PMS) particles; (3) suspended quartz particles. PMS particles were obtained by grinding PMS inactive chimney rocks collected at the hydrothermal vent field Lucky Strike. Both particle types were delivered at a concentration of 25 mg L-1. The putative effects of PMS particles were evaluated through measurements of the coral physiological responses at the levels of the organism (oxygen consumption, ammonium excretion), tissue (bioaccumulation of metals) and cell (enzyme activity and gene expression).

Deep-water ecosystems are characterized by relatively low carbonate concentration values and, due to ocean acidification (OA), these habitats might be among the first to be exposed to undersaturated conditions in the forthcoming years. However, until now, very few studies have been conducted to test how cold-water coral (CWC) species react to such changes in the seawater chemistry. The present work aims to investigate the mid-term effect of decreased pH on calcification of the two branching CWC species most widely distributed in the Mediterranean, Lophelia pertusa and Madrepora oculata. No significant effects were observed in the skeletal growth rate, microdensity and porosity of both species after 6 months of exposure. However, while the calcification rate of M. oculata was similar for all colony fragments, a heterogeneous skeletal growth pattern was observed in L. pertusa, the younger nubbins showing higher growth rates than the older ones. A higher energy demand is expected in these young, fast-growing fragments and, therefore, a reduction in calcification might be noticed earlier during long-term exposure to acidified conditions.