Description: During RV SONNE cruise SO242/2 (September 2015) to the DISCOL site in the Peru Basin (SE Pacific), pyrosome carcasses were collected at the seafloor. Aboard, these carcasses were stored frozen and in the lab on land, they were freeze-dried and ground to fine powder. Their carbon and nitrogen content, δ13C and δ15N were measured on an elemental analyzer coupled with a isotope ratio mass spectrometer (EA-c-IRMS).

Description: During RV SONNE cruise SO242/2 (September 2015) to the DISCOL site in the Peru Basin (SE Pacific), pyrosome carcasses were collected at the seafloor. Aboard, these carcasses were stored frozen and in the lab on land, they were freeze-dried and ground to fine powder. Total fatty acid in pyrosome tissue were extracted following the Bligh and Dyer method and their isotopic compositions and concentrations were measured on a gas chromatograph coupled with an isotopic ratio mass spectrometer (EA-c-IRMS).

Description: During RV SONNE cruise SO242/2 (September 2015) to the DISCOL site in the Peru Basin (SE Pacific) push cores of sediment were taken in the abyssal plains with ROV Kiel 6000 (GEOMAR). The sediment cores were sliced in 0-2 and 2-5 cm intervals and stored frozen until further processing ashore. In the lab on land, sediment samples were freeze-dried, ground to fine powder, phospholipid-derived fatty acids (PLFAs) in the sediment were extracted following the Bligh and Dyer method and they were measured on a gas chromatograph coupled with an isotopic ratio mass spectrometer (EA-c-IRMS).

Description: During RV SONNE cruise SO242/2 (September 2015) to the DISCOL site in the Peru Basin (SE Pacific), pyrosome carcasses were at the seafloor. Aboard, these carcasses were stored frozen and in the lab on land, they were freeze-dried and ground to fine powder. Phospholipid-derived fatty acids (PLFAs) in pyrosome tissue were extracted following the Bligh and Dyer method and their isotopic compositions and concentrations were measured on a gas chromatograph coupled with an isotopic ratio mass spectrometer (EA-c-IRMS).

Description: During RV SONNE cruise SO242/2 (September 2015) to the DISCOL site in the Peru Basin (SE Pacific), pyrosome carcasses were collected at the seafloor. Aboard, these carcasses were stored frozen and in the lab on land, they were freeze-dried and ground to fine powder. Neutral lipid-derived fatty acids (NLFAs) in pyrosome tissue were extracted following the Bligh and Dyer method and their isotopic compositions and concentrations were measured on a gas chromatograph coupled with an isotopic ratio mass spectrometer (EA-c-IRMS).

Description: To investigate scavenging communities associated with carcasses of animals from the water column, we performed experimental food fall studies. We deployed baited camera landers with squid (Illex coindetii), jellyfish (Periphylla periphylla) and fish (Scomber scombrus) for 9-25 hours at 1360-1440 m in the Southern Norwegian Sea. The dataset includes all raw count data of scavengers on the food falls sorted by taxon based on image analysis annoated using ImageJ with the Cell Counter plugin and stored long-term in BIIGLE. Scavengers included lysianassid amphipods (mainly Eurythenes gryllus), ophiuroids, decapod shrimp (Bythocaris spp.) as well as Lycodes frigidus (probably a secondary consumer).

Description: The dataset includes taxon counts of the observed background community at the stations prior to the baited lander deployments as well as area calculations per image. Framegrab images from the OFOS videos were extracted in VLC media player (3.0.11 Vetinari) using the snapshot-tool. Framegrabs were taken every 1.5 minute and additionally as close to the seafloor as possible to have the highest possible resolution. Because of variable image quality, the images were classified into good, medium, and poor quality. In each collected image, organisms were identified to the highest possible taxonomic unit and counted with the Multi-Point tool in ImageJ (ImageJ 1.53g). The annotated area in each image was calculated by setting the scale in ImageJ and then calculating the area with the measure-tool. The total area surveyed was calculated by the sum of the analysed images (total = 8-53 m2 per study region).

Description: The data layers provided show current values for seawater temperature, pH, calcite and aragonite saturation (%), oxygen concentration, and particulate organic carbon (POC) flux to the seafloor at different depths (500, 1000, 2000, 3000, and 4000m) at the present day (1951-2000) and changes in these variables expected between 2041-2060 and 2081-2100 under different RCP scenarios. The data layers were generated following the methods described in Levin et al. (2020). In short, in 2019, we obtained the present day and future ocean projections for the different years which were compiled from all available data generated by Earth Systems Models as part of the Coupled Model Inter-comparison Project Phase 5 (CMIP5) to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Three Earth System Models, including GFDL‐ESM‐2G, IPSL‐CM5A‐MR, and MPI‐ESM‐MR were collected and multi-model averages of temperature, pH, O2 , export production at 100-m depth (epc100), carbonate ion concentration (co3), and carbonate ion concentration for seawater in equilibrium with aragonite (co3satarg) and calcite (co3satcalc) were calculated. The epc100 was converted to export POC flux at the seafloor using the Martin curve (Martin et al., 1987) following the equation: POC flux = export production*(depth/export depth)0.858. The export depth was set to 100 m, and the water depth using the ETOPO1 Global Relief Model (Amante and Eakins, 2008). Seafloor aragonite and calcite saturation were computed by dividing co3 by co3satarg and co3satcalc. All variableswere reported as the inter-annual mean projections between 1951-2000, 2041-2060, and 2081-2100. The data for calcite and aragonite saturation can be found in Morato et al. (2020).

Description: A total of eight deployments of an autonomous baited camera lander were conducted at the Cabo Verde Abyssal Plain (tropical East Atlantic, Lat. 14.72, Lon. -25.19, Water depth ~4200 m) using either Atlantic mackerel (Scomber scombrus, n=4) or Patagonian squid (Doryteuthis gahi, n=4) bait, to photograph organisms attracted to the bait over roughly 24 hours. The deployments took place during the iMirabilis2 campaign in August 2021 from the research vessel Sarmiento de Gamboa. A deep-sea time lapse camera system with an oblique view of the bait plate (12 cm x 45 cm) and surroundings took a picture every 150 seconds. The bar attached to the bait plate is 6 cm wide. The camera was located about 120 cm above the seafloor with an oblique view of 40 degrees (assuming straight down in 0 degrees). Annotations were performed in BIIGLE software (Langenkämper et al. 2017) on every second photograph, providing the morphospecies group label (or 'No ID' if to morphospecies level was not possible) and the taxonomic hierarchy to a level of best confidence for each annotation. Annotations were rectangular in shape, enclosing each individual so that the centre of the annotation was roughly the centre of mass, and the points of each rectangle corner are provided in pixels (x,y) where the lower left corner of the picture is 0,0. Images were 6000 pixels in width and 4000 pixels in height.

Description: This dataset comprises the physiological and behavioural stress response of the deep pelagic jellyfish Periphylla periphylla to anthropogenic disturbance. Specifically, we tested the effects of ocean warming and sediment plumes from deep-sea mining during ex situ experiments, using Periphylla collected in the Lurefjord and Sognefjord, Norway, in 2021. Measurement outcomes include respiration from fiber optics or through electron transfer system analysis (Bode et al. 2013), ammonium excretion (Holmes et al. 1999) and a health score associated with the response to sediment plumes. Microbial community composition and taxonomy were also investigated and results are published in the related dataset https://doi.org/10.1594/PANGAEA.957395.