Sediment properties, benthic biogenic compounds, benthic fauna density and biomasses, and benthic diffusive and total fluxes from three stations (Faro, Creek, Isla D) in Potter Cove, Antarctic

• Main Authors: Hoffmann, Ralf, Pasotti, Francesca, Vázquez, Susana, Lefaible, Nene, Wenzhöfer, Frank, Braeckman, Ulrike
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 2018
• Subjects: Antarc*; Antarctic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.886232; https://doi.org/10.1594/PANGAEA.886232

For the determination of sediment properties and biogenic sediment compounds, sediment was sampled with 3.6 cm diameter cores in five replicates by SCUBA divers. Sediment subsamples were taken with cut-off syringes (cross-sectional area = 1.65 cm²) and sliced in 1 cm intervals down to 5 cm sediment depth. Each interval was analyzed for various parameters including median grain size, porosity, photosynthetic pigments, total carbon, total organic carbon and total nitrogen. Sediment samples for photosynthetic pigments were stored at -80°C. Sediment samples of other parameters were stored at -20°C. The median grain size was determined with a Malvern Mastersizer 2000G, hydro version 5.40. Sediment porosity was determined after drying sediment samples over minimum two days at 105°C. The sediment porosity was calculated following Burdrige (2006, Geochemistry of marine sediments, Princeton University Press). Chlorophyll a (Chl a), phaeophytin (Phaeo) and fucoxanthin (Fuco) pigment concentrations were determined by HPLC The total carbon (TC) and total nitrogen (TN) was measured by combustion using an ELTRA CS2000The total organic carbon (TOC) was measured using the same method, but after acidifying the sample (3 ml of 10 M HCl). For prokaryotic density determination, five replicate sediment sub-samples were taken with cut-off syringes (cross-sectional area = 1.65 cm²), sliced at 1 cm intervals down to 5 cm sediment depth, fixed in a 2% formaldehyde/seawater filtered solution (9 ml) and stored at 4°C. The acridine-orange-direct-count method after Hobbie (1977, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC170856/) was used to stain prokaryotes in the sub-samples and subsequently counted with a microscope (Axioskop 50, Zeiss) under UV-light (CQ-HXP-120, LEj, Germany). For each sample, single cells were counted on two replicate filters and for 30 random grids per filter (dilution factor 4000). Prokaryotic biomass was estimated by the determination of the mean prokaryotic cell volume in the first two centimetres with a "New ...