ALBERT

Description: The structure and composition of Late Pleistocene ice wedges in the ice complex outcropping onto gently sloping Kular ridge in the western Yana-Indigirka Lowland are considered. Ice wedges are dated 47-42 and 37-32 kyr BP. Over this time, relatively high temperatures of the growing season were recorded twice. Their rise appeared to be suffi cient for the growth of trees, while a relatively warm summer season activated slope processes and accumulation of slope yedoma deposits.

Description: Anthropogenic carbon dioxide (CO2) emissions are being absorbed by the oceans, a process known as ocean acidification, and risks adversely affecting a variety of behaviours in a range of marine species, including inhibited learning in some fishes. However, the effects of elevated CO2 on learning in advanced invertebrates such as cephalopods are unknown. Any impacts to the learning abilities of cephalopods could have far-reaching consequences for their populations and the communities they inhabit. Cephalopods have some of the most advanced cognitive abilities among invertebrates and are one of the few invertebrate taxa in which conditional discrimination has been demonstrated, though the trait has not been demonstrated in any species of squid. Here, we tested for the first time the capacity for conditional discrimination in a squid species (Sepioteuthis lessoniana). Furthermore, we investigated the effects of projected future CO2 levels (1,084 µatm) on conditional discrimination and learning more generally. A three-task experiment within a two-choice arena was used to test learning and conditional discrimination. Learning was measured by improvements in task completion in repeated trials over time and the number of trials required to pass each task. Squid exhibited significant learning capabilities, with an increase in correct choices over successive trials and a decrease in the number of trials needed to complete the successive tasks. Six of the 12 squid tested successfully passed all three tasks indicating a capacity for conditional discrimination in the species. Elevated CO2 had no effect on learning or on the capacity for conditional discrimination in squid. This study highlights the remarkable cognitive abilities of S. lessoniana, demonstrated by their capacity for conditional discrimination, and suggests that ocean acidification will not compromise learning abilities. However, other behavioural traits in the species have been shown to be altered at comparable elevated CO2 conditions. It is not clear why some ecologically important behaviours are altered by elevated CO2 whereas others are unaffected. Future research should focus on the physiological mechanism responsible for altered behaviours in squid at elevated CO2.

Description: Ocean acidification and warming are challenging marine organisms and ecosystems around the world. The synergetic effects of these two climate change stressors on jellyfish remain still understudied. Here, we examine the independent and combined effects of these two environmental variables on polyp population dynamics of the Mediterranean jellyfish Cotylorhiza tuberculata. An experiment was conducted to examine asexual reproduction by budding and strobilation considering current and ca. 2100 winter (Trial 1, 36 days) and summer (Trial 2, 36 days) conditions under the RCP8.5 (IPCC 2013). In Trial 1, a temperature of 18°C and two pH levels (current: 7.9 and, reduced: 7.7) were tested. Trial 2 considered two temperature levels 24°C and 30°C, under current and reduced acidification conditions (8.0 and 7.7, respectively). Ephyrae size and statolith formation of released ephyrae from polyps exposed to summer temperatures under both acidification treatment was also analyzed. Zooxanthellae density inside the polyps throughout the experiment was measured. C. tuberculata polyps could cope with the conditions mimicked in all experimental treatments and no significant effect of pH, temperature, or the combination of both variables on the abundance of polyps was observed. At 18°C, strobilation was reduced under high PCO2 conditions. Under summer treatments (24°C and 30°C), percentage strobilation was very low and several released ephyrae suffered malformations and reduced size, as a consequence of reduced pH and elevated temperatures, separately. The number of statoliths was not affected by pH or temperature, however, bigger statoliths were formed at elevated temperatures (30°C). Finally, zooxanthellae density was not affected by experimental conditions, even if, the duration of the experiment significantly affected symbiont concentration. Our results show that even though polyps of C. tuberculata would thrive the future worst scenario predicted for the Mediterranean Sea, their capacity to undergo a proper strobilation and to produce healthy ephyrae will be more vulnerable to climate induced environmental conditions, thereby affecting medusae recruitment and, therefore, population dynamics of the species.

Description: Flow cytometry samples for the measurement of virus-like particles and prokaryotic abundance were sampled from the sea-surface microlayer inside and outside a natural surface slick and respective underlying water samples at three sites in the Kalmar Sound, near Rockneby, Sweden, using a boat. A glass plate sampler and a Ruttner sampler were used to sample the sea-surface microlayer and underlying water from 70 cm depth, respectively. For site 1, dissolved organic carbon and surfactants were additionally measured in all four sample types. Samples for flow cytometry were fixed with glutardialdehyde (0.5% final concentration). Some metadata for wind speed, temperature and salinity were collected. These data complement metagenomic analysis of viral communities in the sea-surface microlayer of a natural surface slick (Rahlff et al., unpublished).

Description: The case study of Dún Laoghaire Harbour in Ireland from 1925–1931 illustrates the challenges of accurately digitizing marigrams. The methodology involves digitizing the original marigram trace and the underlying grid at the nearest foot interval for each given hour to assess offsets. By subtracting the digitized foot interval from the known foot interval, differences are determined and then subtracted from each hourly trace value. This comparison between the original and adjusted data, where the upper and lower bounds were consistently aligned with the top line thickness during calibration, enhances the accuracy of final sea level data to the 10 mm level per year of data. The accompanying paper outlines the digitization and adjustment methodology, along with the compilation of key metadata. The attached metadata file in the dataset download explains the structure of the dataset, including its levels. The accurately digitized records from 1925 to 1931 can help us understand sea level changes over time.

Description: This dataset, titled the Arctic Boreal Burned Area (ABBA) product, provides annual cumulative end-of-season burned area in circumpolar boreal forests and tundra at 463 m for the years 2002-2022. The data were generated based on data inputs collected by NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instruments using an algorithm developed by Loboda et al. (2011). Because this algorithm is specific to the high northern latitude (HNL) regions (i.e., it takes into account various conditions that are unique to the HNL), ABBA maps burned areas more accurately than other counterparts at this resolution.

Description: The Holocene delta deposit (1st terrace) exposure SOB14-A-21 (72.53671°N, 127.98945°E) was sampled on 17 August 2014 North of Sobo-Sise Island in the Lena Delta during the framework of the joint Russian-German Expedition LENA 2014. The surface (top) of the exposure was characterized by mosses and sedges. The exposure itself was predominately sandy with few organic remnants. The top organic layer is thin (1.5 cm) and the active layer depth could not be determined exactly. However, the top 170 cm of the exposure were unfrozen although the thaw front might not only be from the top down but also horizontally due to the nature of the exposure. The exposure was first cleaned with a spade and then sampled with a knife and a hole saw from top to bottom. The entire exposure had a depth of 605 cm whereof the bottom 35 cm consisted of ice. Every 25 cm a sample was collected resulting in 22 samples (20 sediment samples and 2 ice samples). The samples were kept cool during the transport and later analyzed in the laboratory for bulk density, total organic carbon, and total nitrogen with a Vario EL III Elemental Analyzer. Prior to analysis, samples were freeze-dried, homogenized, and ground before measuring the samples with the elemental analyzer. The ice samples were not analyzed.

Description: Here we present a photogrammetric reconstruction of the best developed coral reefs of the Colombian Pacific, located at Gorgona Island. A shapefile containing the detail of coral reef boundaries, used to calculate areas is also included. Dataset includes four (4) orthophotomosaics (GeoTIFF) of the next coral reefs : La Azufrada, Playa Blanca, Arrecifito, Old Pier, and one (1) shapefile.

Description: The values of carbon remineralisation were measured in juveniles/adults of 5 non-migratory bristlemouth fishes (Cyclothone spp.) and partial migrator (Argyropelecus hemigymnus) sampled during the BATHYPELAGIC cruise (North Atlantic, June 2018). This dataset contains the values of numerical abundance, biomass, specific ETS activity, specific respiraton and respiration flux data analyzed from Northwest Africa (20° N, 20° W) to the South of Iceland. A. hemigymnus specimens were collected using a ''Mesopelagos” net (5 x7 m mouth opening, 58 m total length) equipped with graded-mesh netting (starting with 30 mm and ending with 4 mm) and a multi-sampler for collecting samples from 5 different depth layers (Olivar et al., 2017). However, Cyclothone specimens were collected using the Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS-1 m²) zooplankton net (Wiebe et al., 1985) with a 0.2 mm mesh size and with several nets for collecting samples from 8 different depth layers. The Mesopelagos catches were sorted out and identified on board to the lowest possible taxon, and specimens selected for Electron Transfer System (ETS) analyses were immediately frozen in liquid nitrogen for later analysis in the laboratory. MOCNESS samples were preserved in 5% buffered formalin, and specimens were sorted out later in the laboratory. Stomiiforms respiration in the meso- and bathypelagic zones of the ocean were estimated along the transect. Abundance, biomass, specific ETS activity, specific respiration and respiration are given by layer.

Description: The effect of different nitrogen sources (N-deplete, NO3-, NH4+, Urea) on the growth response and toxin content of Alexandrium pseudogonyaulax, isolated in 2020 from the Danish Limfjord, were investigated by means of a bottle incubation experiment. The experiment was started on the 18th October 2021 and finished on the 13th December 2021. This dataset contains all data collected within the experiment, including cell counts, cell sizes, goniodomin A toxin contents, particular organic carbon.