Bottom Water Sampler
The metabolism of benthic and near-bottom fauna such as oxygen respiration and nutrient re-mineralization as well as sub-seafloor fluid discharge can generate steep solute gradients within the bottom boundary layer. Sampling within the first meters above the seafloor is difficult by conventional equipment (e.g. CTD rosette samplers). In order to close the gap between water column and sea floor sampling, a special bottom water sampler (BoWaSnapper) was developed, capable of resolving this near bottom zone.
Steep near-bottom methane gradients above a submarine mud volcano.
Schematic drawing of the device.
Deployment of the bottom water sampler from R/V L’Atalante in the North Atlantic.
The wire-operated robust device aligns itself within the bottom current and is flushed through by the ambient bottom water while standing for several minutes on the seafloor before sample bottles are closed. Samples can be used for microbiological, biogeochemical and tracer investigations. The sampler has proven its functionality as a routine device in water depths up to 5500 m during numerous cruises with RV “Polarstern“, “L’Atalante”, “Alkor”, and „Littorina“.
... and in the rough Southern Ocean.
Deployment of the bottom water sampler on RV “Polarstern“ in the ice covered Greenland Sea ...
The patented bottom water sampler can now be purchased from K.U.M. GmbH, Kiel under the product name BoWaSnapper. Individual modifications are possible.
Literature
Sauter, E. J., Schlüter, M., Wegner, J., Labahn, E.(2005). A routine device for high resolution bottom water sampling, Journal of sea research, 54, 204-210.
Sauter, E.J. Schlüter, M., Charlou, J.-L., Muyakshin, S.I., Boetius, A., Damm, E., Klages, M., Foucher, J.-P. (2005) Estimating the importance of different pathways of methane discharge from deep-sea submarine sources, Geophys. Res. Abstr. 7 (2005) 04559.
Sauter, E., Schlüter, M., Boetius, A., Baumann, L. (2002). Geochemistry of Hakon Mosby Mud Vulcano (HMMV) bottom water and sediments, Reports on Polar and Marine Research, 422, 47-53.
Sauter, E. (2002). Bodenwaser-Probennehmer mit in der Strömung ausrichtbaren Probenflaschen (Bed water sampling device), Granted German Patent 10232623.1, other IPRs pending.
Contact: E. Sauter