ALBERT

Description: The original set of botanical collections of the agronomist H.A. Homblé is conserved in the herbarium BR. Homblé was one of the first collectors (1911–1913) for the flora of Katanga, Democratic Republic of the Congo. Many Homblé specimens were described as taxonomic novelties; 107 tropical African plant species are named after him. Before his colonial career in Katanga, Homblé stayed about two years (1909–1911) in Guangxi, China. His incompletely labelled Chinese collections were erroneously considered as collected in Katanga. This supposed African origin has led to confusion with regard to the identification, and even resulted in the description of four species believed to be new for science. This paper presents and discusses Homblé’s collection made in Guangxi, and the assumed novelties in it. Drosera insolita is a synonym of the Asian Drosera lunata, widespread from India to Australia. Three other species are new synonyms. Caesalpinia homblei is a synonym of the pantropical Caesalpinia bonduc. Digitaria polybotryoides is a synonym of Digitaria abludens, a widespread species in tropical Asia. Grewia katangensis is the only species that proved to be synonymous with an endemic species, Grewia cuspidatoserrata, only known from S Yunnan, and here reported as a new record for Guangxi. Lysimachia candida and Impatiens chinensis should be deleted from the list of the Congo Flora. The importance of careful specimen labelling and label interpretation is discussed.

Description: This dataset contains abiotic and biotic data from sediment samples from nine sites in the Weddell Sea (mostly South-Eastern). Data are provided for sediment pigments (chlorophyll a and phaeopigment content through fluorometry), total organic carbon (TOC), total nitrogen (TN), stable isotope values of carbon and nitrogen (δ13C, δ15N) and grain size (silt&clay 〈 32 µm, very fine sand 63–125 µm sand, fine sand 125–250 µm, medium sand 250–500 µm, coarse sand 500–1000 µm, larger coarse sand 〉 1000 µm). Before the TOC and carbon isotope analysis the sediment samples were acidified to eliminate inorganic carbon. A minimum of three replicate samples (cores) were collected using a MUC10 multicorer or giant box corer. Sediment cores were subsampled with a 60-ml syringe (inner diameter 2.7 cm) for stations 017, 026, 061, 072, and with a 10-ml syringe (inner diameter 1 cm) for stations 001, 037, 048, 104, 115. Subsamples were sliced in 1-cm steps down to 5 cm depth. Detailed methods are described in Säring et al. (submitted) except for stable isotopes: Flash combustion in a Flash 2000 (Thermo) elemental analyser to a Delta V advantage (Thermo) isotope ratio masspectrometer. δ values are reported relative to atmospheric N2 (δ15N) and Vienna PeeDee Belemnite (δ13C). Reference materials for stable isotope analysis: IAEA-N1, IAEA-N2, IAEA-N3, NBS 22, IAEA-CH-3 and IAEA-CH-6; calibration material: Acetanilide (Merck). The analytical precision for both stable isotope ratios was 〈±0.2‰. Cores with the label -e (Environment) were only used to collect the above data. Environmental and fauna data were collected from cores with the label -i (Incubation). This data table is part of a larger study analysing the role of environmental parameters for meio- and macrofaunal community composition (see Related to below).

Description: Swath sonar bathymetry data used for that dataset was recorded during RV SONNE during cruise SO276 using Kongsberg EM 122 multibeam echosounder. The cruise took place between 22.06.2020 - 26.07.2020 in the Atlanic Ocean. Data were recorded throughout the whole time spend outside EEZs. The approximate average depth of the entire dataset is around 4000m. To enhance MBES data accuracy, sound velocity profile casts were conducted in the vicinity of the working area prior to the survey using CTD rosette. During transits, sound velocity profile from the WOA13 were aplied via Sound Speed Manager Software. After processing, these data were directly imported into the MBES Acquisition software Kongsberg SIS Seafloor Information System. Data were manually edited for false measurements using Qimera. Raster were calculated and stored in GeoTIFF format with a 100m resolution (negative values), WGS85 as vertical datum and UTM as a projection, both for EM122 & EM710. Data products include ungridded soundings and bathymetric grids (100 m resolution) of the entire cruise for each EM122 & EM710. The data processing and provision was accomplished within work package 2 of the EU Horizon 2020 project iAtlantic- Integrated Assessment of Atlantic Marine Ecosystem in Space and Time and the IceAge project.

Description: Raw multibeam bathymetry data were recorded on RV SONNE during SO276 using Kongsberg EM710 multibeam echosounder. The cruise took place between 22.06.2020 - 26.07.2020 in the Atlantic Ocean. Data were recorded throughout the whole time spend outside EEZs in areas shallower than 1500m with an approximate average depth of around 400m. To enhance MBES data accuracy, CTD casts were made in the working area prior to each MBES survey using CTD rosette to raytrace beams with the obtained sound velocity profiles (SVP). During transits, SVPs from the WOA13 were applied via Sound Speed Manager Software to the data directly during acquisition with SIS Seafloor Information System. Data are unprocessed and can therefore contain incorrect depth measurements (artifacts) without further processing. The data are archived at the Federal Maritime and Hydrographic Agency of Germany (Bundesamt für Seeschifffahrt und Hydrographie, BSH) and provided to PANGAEA database for data curation and publication. Ancillary sound velocity profiles (SVP) files from the cruise are archived at the BSH, thus SVP files are added to this dataset. Data acquisition and provision were accomplished within work package 2 of the EU Horizon 2020 project iAtlantic- Integrated Assessment of Atlantic Marine Ecosystem in Space and Time (https://www.iatlantic.eu/) IceAge project.

Description: The dataset is about temporal variability of dissolved methane along the freshwater-sea continuum in northern Germany. Sensors were installed at fixed stations at in total three sites at different water depths. This dataset is from the station in Cuxhaven (53.8771 N, 8.7048 E) taken at about 2-7m depth (depending on the tide). The data was obtained between 11 April and 28 August 2021 in high frequency measurements (1 min) with a methane sensor from Kongsberg (4H Jena model CONTROS HydroC CH4). Methane concentrations were calculated according to manufacturer's instructions, based on temperature and salinity values from COSYNA Container Cuxhaven. For the quality control of the data a local range of 0.1 – 1000 nmol/L was set, a technical range for the pump power 2 – 8 Watt, a spike and gradient value of 1. Due to heavy biofouling the external pump of the sensor failed, resulting in data gaps. For a more detailed description see the article cited in References.

Description: To determine the effect of the rate of temperature increase (acute vs. gradual) and magnitude as well as the timing of nutrient addition on a natural marine phytoplankton community, a bottle incubation experiment has been conducted at the Institute for Chemistry and Biology of the Marine Environment (ICBM) in Wilhelmshaven, Germany. The community was collected at the Helgoland Roads long-term time series site in the German part of the North Sea (https://deims.org/1e96ef9b-0915-4661-849f-b3a72f5aa9b1) on the 6ᵗʰ of March 2022. The surface water containing the phytoplankton community was collected from the RV HEINCKE with a pipe covered with a 200 µm net attached to a diaphragm pump. In the first experimental run, the community was exposed to either gradual or acute temperature increase (from 6 to either 12 or 18°C) with 25 different N:P supply ratios added as a batch at the beginning of the bottle incubation. Simultaneously, the same community was gradually acclimated to their experimental temperatures under ambient nutrients and was used in a second experimental run in which it received the same 25 different N:P supply ratios after temperature acclimation. The light conditions were set to 175 µmol s-1 m-2 and a day-night cycle of 12h:12h which corresponds to the natural conditions at that time of the year. With this, it was possible to test the effect of a gradual vs. acute temperature increase and the timing of nutrient addition i.e., before or after the temperature change. This experimental set-up summed up to 400 units (8 temperature treatments x 5 nitrogen levels x 5 phosphorus levels x 2 replicates). Each experimental run was ended after 12 days. Fluorescence (395/680 Exc./Em.) was measured every second day using a SYNERGY H1 microplate reader (BioTek®) to determine phototrophic growth over time. At the end of each experiment, one replicate was filtered onto pre-combusted acid-washed glass microfiber filters (WHATMAN® GF/C) for intracellular carbon (POC), nitrogen (PON), and phosphorus (POP) content. The POP filters were pre-combusted and then analysed by molybdate reaction after digestion with a potassium peroxydisulfate solution (Wetzel and Likens 2003). The POC and PON filters were dried at 60°C before they were measured in an elemental analyser (Flash EA 1112, Thermo Scientific, Walthman, MA, USA).

Description: Baffin Bay is a semi-enclosed basin connecting the Arctic Ocean and the western North Atlantic, thus making out a significant pathway for heat exchange. Here we reconstruct the alternating advection of relatively warmer and saline Atlantic waters versus the incursion of colder Arctic water masses entering Baffin Bay through the multiple gateways in the Canadian Arctic Archipelago and the Nares Strait during the Holocene. We carried out benthic foraminiferal assemblage analyses, X-ray fluorescence scanning, and radiocarbon dating of a 738 cm long marine sediment core retrieved from eastern Baffin Bay near Upernavik, Greenland (Core AMD14-204C; 987m water depth). Results reveal that eastern Baffin Bay was subjected to several oceanographic changes during the last 9.2 kyrCE1. Waning deglacial conditions with enhanced meltwater influxes and an extensive sea-ice cover prevailed in eastern Baffin Bay from 9.2 to 7.9 ka. A transition towards bottom water amelioration is recorded at 7.9 ka by increased advection of Atlantic water masses, encompassing the Holocene Thermal Maximum. A cold period with growing sea-ice cover at 6.7 ka interrupts the overall warm subsurface water conditions, promoted by a weaker northward flow of Atlantic waters. The onset of the neoglaciation at ca. 2.9 ka is marked by an abrupt transition towards a benthic fauna dominated by agglutinated species, likely in part explained by a reduction of the influx of Atlantic Water, allowing an increased influx of the cold, corrosive Baffin Bay Deep Water originating from the Arctic Ocean to enter Baffin Bay through the Nares Strait. These cold subsurface water conditions persisted throughout the Late Holocene, only interrupted by short-lived warmings superimposed on this cooling trend.

Description: This dataset provides abundance data for meiofauna taxa determined from sediment samples collected in the Weddell Sea (mostly South-Eastern). A minimum of three samples (cores) were collected at each station with a MUC10 multicorer or taken from a giant box corer during PS96. Sediment cores were sliced into depth layers (stations 017, 026, 061, 072: 0–2cm, 2–5cm, 5– bottom; stations 001, 037, 048: 0–1cm, 1–2cm, 2–3cm, 3–4cm, 4–5cm, 5– bottom) and preserved in 4%-borax-buffered formaldehyde solution prior to sieving (upper sieve size 500 µm, lower sieve size 32 µm) and counting (detailed methods in Säring et al. submitted). Abundance is presented per depth layer from the top 5 cm (note different slice volume) as ind./10 cm². Meiofauna communities included individuals from 22 higher taxa. The meiofauna abundance data are part of a larger ecological study on meio- and macrofauna communities and their relation to environmental conditions and remineralisation at the sediment-water interface (see “Related to” below). For the larger study, sediment cores from which meiofauna abundance data are deposited here were also used for microcosm incubations: Untreated incubations (Benthic ecosystem Function Experiments BEFEx), and incubations with and without microalgae addition (Algae Feeding Experiment AFEx). Cores from BEFEx and AFEx without algae are labeled with NT (not treated), cores from AFEx with algae are labeled as T (treated).