Bacteria, meiofauna and macrofauna density and macrofauna biomass in the HAUSGARTEN area (Fram Strait) in 2015 (POLARSTERN cruise PS93.2)

• Main Authors: Braeckman, Ulrike, Hoffmann, Ralf
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2018
• Subjects: Event label; Date/Time of event; Latitude of event; Longitude of event; Elevation of event; Replicate; Station label; DEPTH, sediment/rock; Bacteria per unit wet sediment; Meiofauna, abundance; Macrofauna, biomass, wet mass; Macrofauna, abundance; Bottom lander; Multicorer with television; PS93.2; Polarstern; Long-term Investigation at AWI-Hausgarten off Svalbard Hausgarten; Svalbard; Fram Strait
• Online Access: https://dx.doi.org/10.1594/pangaea.884601; https://doi.pangaea.de/10.1594/PANGAEA.884601

During PS93.2 (in 2015) bacteria density, meiofauna density, macrofauna density and macrofauna biomass was determined. For the bacterial density determination, sediment subsamples were taken with modified syringes (1.17 cm² cross-sectional area) from MUC recovered sediment cores and from benthic chambers. The first centimetre of each sample was stored in a 2 % filtered formalin solution at 4 °C. The acridine orange direct count (AODC) method (Hobbie et al., 1977) was used to stain bacteria in the subsamples and subsequently bacteria were counted with a microscope (Axioskop 50, Zeiss) under UV-light (CQ-HXP-120, LEj, Germany). For the determination of the meiofauna density and identification of meiofauna taxa, sediment subsamples were taken with modified syringes (3.14 cm² cross-sectional area) from MUC recovered sediment cores. The first centimetre of each sample was stored in borax buffered 4 % formaldehyde solution at 4 °C. The samples were sieved over a 1000 µm and 32 µm mesh. Both fractions were centrifuged three times in a colloidal silica solution (Ludox TM-50) with a density of 1.18 g/cm³ and stained with Rose 20 Bengal (Heip et al., 1985). Afterwards, the taxa were identified and counted. Foraminifera are not considered, as the extraction efficiency of Ludox for different groups of foraminifera is insufficient for a quantitative assessment of the group. Therefore, only metazoan meiofauna is recorded. After taking subsamples for bacteria and meiofauna densities, the remaining sediment from MUC recovered sediment cores and from the benthic chambers was used for macrofauna taxonomical identification, and density and biomass determination. For these macrofauna analyses only the 0-5 cm horizon from MUC sediment cores and the entire remaining sediment from the benthic chambers was used, sieved over a 500 µm mesh and stored in borax buffered 4 % formaldehyde and stained with Rose Bengal (Heip et al., 1985). Afterwards, macrofauna taxa were identified to the highest taxonomic level, counted and weighted (blotted wet weight).