KRILLBASE is a data rescue and compilation project which aims to improve the availability of information on two of the Southern Ocean''s most important zooplankton taxa: Antarctic krill (Euphausia superba) and salps (Family Salpidae). In 2016, the project released a database of information from 15,194 scientific net hauls, collected between 1926 and 2016 by scientists from ten countries. These data, on the density of Antarctic krill and salps, provide a resource for analysing the distribution and abundance of these taxa throughout the Southern Ocean, to support ecological and biogeochemical research as well as fisheries management and conservation. The data are available as a downloadable csv files and via a seachable web interface. Each row of the main data table represents either a net haul or a composite of several net hauls. The columns describe searchable and filterable sampling and environmental information as well as the krill and salp density. The krill data are presented as both the observed density (NUMBER_OF_KRILL_UNDER_1M2, no.m-2) and the density standardised to a single, relatively efficient sampling method (STANDARDISED_KRILL_UNDER_1M2, no.m-2). The salp data are presented as observed density for all species combined, where an individual can be either a solitary oozoid or a member of an aggregate chain (NUMBER_OF_SALPS_UNDER_1M2, no.m-2). 12,758 of the net hauls in the database include krill data, 9,726 include salp data. 7,295 of the net hauls include both krill and salp data. For hauls where data for either salps or krill were not available the relevant field is blank. The RECORD_TYPE column distinguishes between four types of record and we emphasise that every analysis of the data should first screen on this field to avoid using the same data twice. Most records are labelled "haul", and these result from a single net sampling the water column at a specific station. Others, labelled "stratified pooled haul", are the combined result of several (typically three) stratified hauls (labelled "stratified haul") sampling different parts of the water column. A small number of records, labelled "survey mean" represent the arithmetic mean densities from multiple stations as this was the only recoverable information from the relevant surveys, which were mainly conducted in the 1980s. The dataset is fully described in the following publication which should be cited in published analyses of these data: Atkinson A, Hill SL, Pakhomov E, Siegel V, Anadon R, Chiba S, Daly KL, Downie R, Fielding S, Fretwell P, Gerrish L, Hosie GW, Jessopp MJ, Kawaguchi S, Krafft BA, Loeb V, Nishikawa J, Peat HJ, Reiss CS, Ross RM, Langdon B Quetin, Schmidt K, Steinberg DK, Subramaniam RC, Tarling GA, Ward P (2017) KRILLBASE: a circumpolar database of Antarctic krill and salp numerical densities, 1926-2016. Earth Syst. Sci. Data, 9: 193-210 (doi:10.5194/essd-9-193-2017)

Quantification of interactive effects of ocean warming and ocean acidification based on near-future climate change projections on morphometrics and oocyte size of benthic invertebrates (the bivalves Astarte crenata and Bathyarca glacialis) from the Western Barents Sea. Supported by The Changing Arctic Ocean Seafloor (ChAOS) - how changing sea ice conditions impact biological communities, biogeochemical processes and ecosystems project (NE/N015894/1 and NE/P006426/1, 2017-2021), Natural Environment Research Council (NERC) in the UK.

This dataset contains data from a study of pteropod shell dissolution on individuals exposed to CO2-enriched seawater. The data include the amount of dissolution as well as the physical and chemical parameters on which carbonate chemistry parameters were calculated.

Quantification of morphological and reproductive traits in Astarte crenata and Ctenodiscus crispatus (oocyte size/gonad index), used in the analyses by Reed et al. 2021 (Ecology and Evolution) from the Western Barents Sea during summer 2017 across a North - South Transect intersecting the polar front.

Images of histological sections of oocytes to quantify oocyte size frequency distributions in Astarte crenata and Ctenodiscus crispatus used in the analyses by Reed et al. 2021 (Ecology and Evolution) from the Western Barents Sea during summer 2017 across a North - South transect intersecting the polar front. Supported by The Changing Arctic Ocean Seafloor (ChAOS) - how changing sea ice conditions impact biological communities, biogeochemical processes and ecosystems project (NE/N015894/1 and NE/P006426/1, 2017-2021), Natural Environment Research Council (NERC) in the UK.

Images of histological sections of oocytes to quantify the interactive effects of ocean warming and ocean acidification based on near-future climate change projections on oocyte size frequency distributions of benthic invertebrates (the bivalves Astarte crenata and Bathyarca glacialis) from the Western Barents Sea. Supported by The Changing Arctic Ocean Seafloor (ChAOS) - how changing sea ice conditions impact biological communities, biogeochemical processes and ecosystems project (NE/N015894/1 and NE/P006426/1, 2017-2021), Natural Environment Research Council (NERC) in the UK.

Multiple images of the seafloor at six sites across a broad latitudinal range in the Barents Sea in the Arctic were collected in July 2017 on the month long scientific cruise JR16006. The dataset includes environmental variables for each accompanied image. Each image (406 x 341mm) has density of fauna from different functional groups. We have 13 different functional groups based on other similar studies. The aim was to look at the effect of climate change in the Arctic on the biology of the seafloor. Funding was provided by the NERC Changing Arctic Oceans ChAOS project.

Multiple arrays with heated panels (1 degree Celsius and 2 degrees Celsius above ambient temperature and non-heated) were deployed subtidally in the Menai Strait for a period of 13 months from the summer of 2015 to the summer of 2016. The effect of temperature on species composition of the assemblage, seasonal effects and on the growth rates of one of the main colonisers, the polychaete Spirobranchus triqueter was assessed. Underwater photographs of the panels were taken regularly over the course of 13 months. The images were merged into a single image using Photoshop CS5. The growth rate of the main coloniser Spirobranchus triqueter and species diversity and percentage of the panel community were measured using Fiji(ImageJ) and Rstudio. This project was funded by NERC: reference NE/J007501/1 "Effects of warming on recruitment and marine benthic community development in Antarctica".

During the IceDivA2 expedition on RV Sonne in November 2021, specimens of a megafaunal scaphopod species were collected by Agassiz trawl (AGT) and imaged by an Ocean Floor Observation System (OFOS) in the Labrador Sea Basin at abyssal depths of 3380 to 3390 m. Morphological, morphometric and genetic analyses revealed an undescribed species of the scaphopod genus Fissidentalium, which was formally described as Fissidentalium aurae sp. nov. by Linse and Neuhaus in 2024. In-situ images of RV Sonne''s OFOS system revealed a shallow inbenthic lifestyle of the scaphopod when it is associated with an anemone, leaving Lebensspuren in the soft abyssal sediments and enabled density estimation of the species. This dataset provides data for 1) Fissidentalium aurae sp. nov. presence record from AGT, shell morphometric measurements, and museum curation numbers (.csv), 2) images files (54) of specimens'' shells, soft parts and radula (.jpg), 3) SEM images files (28) of radula and shell structure (.tif), 4) in-situ OFOS images (917) (.jpg), 5) Fissidentalium presence assessment of in-situ OFOS images (.csv). Katrin Linse is part of the British Antarctic Survey Polar Science for Planet Earth Programme funded by The Natural Environment Research Council (NERC) [NC-Science]. Fieldwork during expedition SO286 on RV Sonne was funded by the Federal Ministry of Education and Research (BMBF) through the IceDivA2 grant GPF 21-2_052 given to PIs Saskia Brix, Katrin Linse, Pedro Martinez Arbizu and Alexander Kieneke. Jenny Neuhaus was supported through grant GPF 21-2_052 as well as the iAtlantic project funded by EU/HORIZON 2020, Blue Growth (grant agreement No 818123).

This dataset set describes the developmental stages and the molecular barcoding of Terebellidae larvae identified from diver-collected samples on 2021-04-22 in Ryder Bay near Rothera Research Station, Antarctic Peninsula, Antarctica. Photographs were collected at seven stages across the larval development. Development was captured from the trochophore stage where the polychaete larvae were bound in mucus to the free swimming planktonic metatrochophore to the nectochaete stage. Molecular barcoding was performed using the 18S rRNA gene at the British Antarctic Survey. Funding: This study was funded by core funding to UKRI NERC-BAS.