This dataset is referring to 1-year time series of particle flux, as measured by a shelf moored sediment traps (WCB) located in the Southern Ocean (northern Scotia Sea sector), a globally important region of atmospheric CO2 drawdown. This sector holds >50% of the circumpolar krill stock of Antarctic krill and is the geographic focus for the krill fishing industry. The dataset includes the specific contribution of krill components to the total C flux parameters (such as exuviae, faecal pellets and carcasses) within a period from January to December 2018. Values of krill seasonal standing stock estimated from krill standard lengths is also included in the dataset. The dataset allow the quantification of the relevant contribution of krill to the POC flux. Since abundance of Krill around South Georgia is environmentally influenced, the dataset highlights the sensitivity of POC flux to rapid regional environmental change.
Samples of Antarctic krill, Euphausia superba, were collected during the Discovery 2010 cruise aboard the James Clark Ross (JR177). Krill from two areas were used, one from around 60 South from the vicinity of the South Orkney Islands, and the second from north-west of South Georgia at around 52 South. All of the krill were taken by target fishing.
Data related to Antarctic krill activity monitoring studies conducted in the Southern Ocean and South Atlantic during the Discovery 2010 cruise (JR177), 2007-2008. The activity monitor is a purpose-built apparatus for the observation of vertical migration patterns. Lighting within the apparatus is adjusted to that experienced by the krill at normal daytime depths and the temperature in the cool-room kept at the level of the seawater supply. The movements of the krill over a 10-day period were recorded - 5 days recording their vertical migration patterns under normal lighting conditions followed by 5 days in total darkness to see whether the activity pattern is maintained, indicating control by an endogenous circadian rhythm. Three runs were carried out, using animals from 60.44 S, 59.66 S and 52.75 S. Behaviour in many organisms (including krill) is strongly influenced by diurnal and seasonal changes in the environment. The evolution of circadian clocks has afforded organisms regulation of molecular and physiological rhythms, which in turn affect the animals'' rhythmic behaviour.
Biological fishing samples were collected during multiple cruises in the Southern Ocean between Oct 2002 and Jan 2006. Fishing was undertaken in the area of sub-surface moorings to ground-truth acoustic data being collected. Specifically, RMT (Rectangular Mid-water Trawl) hauls were carried out to learn more about the vertical distribution of plankton, krill, mysids and fish around these particular positions during the day and night time.
The Biological Investigations of Marine Antarctic Systems and Stocks (BIOMASS) Data Set has been created as part of the BIOMASS Programme directed towards deeper understanding of the ecology of the Southern Ocean, with emphasis on krill (Euphausia superba). Data were collected during 34 cruises through a collaboration by 12 countries during three field experiments. These were: the First International BIOMASS Experiment (FIBEX) from November 1980 to April 1981, the Second International BIOMASS Experiment (SIBEX), Part 1 from October 1983 to May 1984 and Part 2 from November 1984 to April 1985. Data were collected on krill distribution from acoustic surveys and krill population structure from net-hauls. Supporting data from ichthyoplankton net-hauls, oceanographic stations (temperature, salinity, nutrients and chlorophyll-a) and observations of sea-birds at sea were also collected. The BIOMASS Data Set is composed of 43 data files, extracted from the BIOMASS Oracle relational database created by the BIOMASS Data Centre that collated and standardised the data. The validation and correction of the data were carried out during data analysis workshops by the BIOMASS Programme scientists who collected the data. The majority of the BIOMASS data have been utilized during BIOMASS workshops. However, some have not been used and must be regarded as unvalidated. The documentation accompanying the BIOMASS data set lists the known problems and validation status of the data. Funding: The BIOMASS Data Set has been generated by the BIOMASS Data Centre funded by the British Antarctic Survey. Main sponsors of the BIOMASS Programme were the Scientific Committee on Antarctic Research (SCAR) and the Scientific Committee on Oceanic Research (SCOR) in collaboration with the International Association for Biological Oceanography and the Advisory Committee on Marine Resources Research of the Food and Agriculture Organization of the UN.
Genetic profiling data relating to studies on Antarctic krill, Euphausia superba, that document the sequence of expression of genes over the moult cycle and the spatial-temporal expression of clock genes. This work was carried out to examine rhythmic behaviour patterns in this species - namely diel vertical migration and the moult cycle - and the functioning of the genes that underlie these behaviours. Circadian entrainment experiments were carried out twice during the Discovery 2010 summer cruise (cruise no JR177) using krill caught in nets at latitudes of 60S and 52S. Krill samples from each net were processed and preserved for subequent analysis using molecular biology technique to isolate canonical clock genes.