Are boundary conditions in surface productivity at the Southern Polar Front reflected in benthic activity?
Brandt, A; Vanreusel, A.; Bracher, A; Hoppe, M; Lins, L.; Meyer-Lobbecke, A; Soppa, A; Wurzberg, L (2014). Are boundary conditions in surface productivity at the Southern Polar Front reflected in benthic activity? Deep-Sea Res., Part II, Top. Stud. Oceanogr. 108: 51-59. dx.doi.org/10.1016/j.dsr2.2014.09.001 In: Deep-Sea Research, Part II. Topical Studies in Oceanography. Pergamon: Oxford. ISSN 0967-0645; e-ISSN 1879-0100, more |  |
| Keyword | | | Author keywords | South Atlantic; Polar front; Primary production; Benthos; Meiofauna;Macrofauna; Densities |
| Authors | | Top | - Brandt, A
- Vanreusel, A., more
- Bracher, A
- Hoppe, M
| - Lins, L., more
- Meyer-Lobbecke, A
- Soppa, A
- Wurzberg, L
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| Abstract | In austral summer 2012, during the expedition ANT-XXVIII/3 on board RV Polarstern, two sites were sampled 1600 km apart in the South Polar Front area (52°S) at the boundary of different productivity regimes for meio- and macrobenthos using a multiple-corer and an epibenthic sledge, respectively. Patterns in density and abundance data were compared between different size classes of the benthos and interpreted in relation to surface primary productivity data and sediment oxygen consumption. We tested the hypothesis that long-term satellite-derived surface phytoplankton biomass, in situ real time biomass, and productivity measurements at the surface and throughout the euphotic zone are reflected in abyssal benthos densities, abundances and activity. Specifically, we investigated the effect of boundary conditions for lower and higher surface productivity. Surface and integrated to 100 m depth biomass and primary productivity measurements vary stations, with the lowest values at station 85 (0.083 mg Chl-a m-3 at surface, 9 mg Chl-a m-2 and 161 mg C m-2 d-1- integrated over the first 100 m depth), and the highest values at station 86 (2.231 mg Chl-a m-3 at surface, 180 mg Chl-a m-2 and 2587 mg C m-2 d-1 integrated over first 100 m depth). Total meiofaunal densities varied between 102 and 335 individuals/10 cm². Densities were the highest at station 86-30 (335 individuals) and lowest at station 81-13 (102 individuals). Total macrofaunal densities (individuals/1000 m²) varied between 26 individuals at station 81-17 and 194 individuals at station 86-24. However, three EBS hauls were taken at station 86 with a minimum of 80 and a maximum of 194 individuals. Sediment oxygen consumption did not vary significantly between stations from east to west. Bentho-pelagic coupling of meio- and macrobenthic communities could not be observed in the South Polar Front at the boundary conditions from low to high surface productivity between stations 81 and 86. |
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