Exuviae krill flux in the northern Scotia Sea from January 2018 to December 2018

• Main Author: Manno, Clara
• Format: Dataset
• Language: English
• Published: UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation 2020
• Subjects: "EARTH SCIENCE","BIOSPHERE","ECOLOGICAL DYNAMICS","ECOSYSTEM FUNCTIONS","BIOMASS DYNAMICS"; "EARTH SCIENCE","BIOLOGICAL CLASSIFICATION","ANIMALS/INVERTEBRATES","ARTHROPODS","CRUSTACEANS","EUPHAUSIIDS KRILL"; "EARTH SCIENCE","OCEANS","OCEAN CHEMISTRY","ORGANIC CARBON"; POC; carbon flux; faecal pellets; krill; sediment trap; Antarctic; Scotia Sea; Southern Ocean; Antarc*; Antarctic Krill
• Online Access: https://dx.doi.org/10.5285/60f9b354-2cbf-4d4d-84f7-13c9224f82d4; https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01408

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. : Sample were collected by using sediment trap deployed on bottom-tethered moorings during WCB cruise JR16003. Once in the laboratory, sample were then divided into a series of replicate fractions for subsequent analysis using a McLane rotary sample splitter (McLane Labs, Falmouth, MA, USA). POC was measured by combustion in an elemental analyser (CHN); Krill faecal pellets were counted under light microscopy. The dimensions of krill faecal pellets were measured (length and width) using an ocular micrometer. Exuviae and carcasses of krill were picked out under a light microscope and their dimensions measured. They were then rinsed and dried at 60 °C for 24 hours before their dry weight (DW) was measured. The length of the uropod from exuviae randomly picked from each sediment trap sample bottle was measured. Krill total length was estimated from uropod length. : - Sediment trap deployed on fixed mooring platform - Sediment trap splitter - CHN auto-analyser - Light microscope - 60 °C owen and balance for dry mass calculation : Physical data acquired during the sediment trap deployment suggest the record was not subjected to major hydrodynamic biases since mean current velocities near to the sediment traps were < 10 cm s-1 and we assumed no significant lateral advection occurred.