FS Polarstern PS117 (GApr12)

Cruise summary report

Cruise Info. 
Ship name (ship code)FS Polarstern (06AQ)
Cruise identifierPS117 (GApr12)
Cruise period2018-12-15 — 2019-02-07
Port of departureCape Town, South Africa
Port of returnPunta Arenas, Chile
ObjectivesPolarstern expedition PS117 focusses on providing contributions to scientific projects encompassing physical oceanography, marine biology and meteorology, with the general aim to better our understanding of the evolution of the Weddell Sea water masses and the ecological and chemical cycles of the Weddell Sea. In addition to the immediate scientific program, this expedition also serves to resupply the German Neumayer Station, Antarctica to support the multifaceted scientific activities originating from there. Specific scientific projects conducted throughout the expedition from aboard are:

- HAFOS (Hybrid Antarctic Float Observing System) investigates the circulation and evolution of Warm Deep Water and Weddell Sea Bottom Water by means of oceanographic deep-sea moorings, hydrographic sections and autonomous floats, the latter of which extend the international Argo Project to the polar seas. Biological aspects of HAFOS concern the acoustic ecology of the Weddell Sea and its fauna, for which moorings are equipped with autonomous recorders.
- FePhyrus will investigate the sources and sinks of trace metals and isotopes in the Weddell Sea and Lazarev Sea and the interaction between iron and the microbial food web.
- SOCCOM (Southern Ocean Carbon and Climate Observations and Modelling) is observing and modelling the biogeochemical cycles of the Southern Ocean as a means of improving climate modelling; observations are made using biogeochemical profiling floats (BGC-Argo) that are being distributed throughout the Southern Ocean. UK PICCOLO (Processes Influencing Carbon Cycling: Observations of the Lower Limb of the Antarctic Overturning) scientists study the key processes controlling the rate of Southern Ocean carbon uptake, via the release of Argo floats and carbonate chemistry data collection on the Greenwich Meridian section in the Weddell Sea.
- The project Microplastics will explore the occurrence and distribution of microplastics in water and biota in the Southern Ocean.
- SIPES 2 (Sea Ice Production and Ecology Study) investigates the ecological importance of sea ice for the pelagic food web and carbon supply to top predators (birds and mammals).
- ALGENOM-2 investigates the molecular evolutionary and ecological dynamics of unicellular eukaryotic assemblages and of selected taxa thereof.
- CombiBac aims for a better understanding of bacterial remineralisation processes in the Weddell Sea with emphasis on their dependence on water temperature and substrate concentration. For this purpose, parameters of bacterial activity, the composition of bacterioplankton communities and concentrations of organic matter will be determined in field samples and during on-board experiments.
- The project "Molecular ecology, physiology and life history tools to monitor the population of Dissostichus mawsoni over time and in relation to protection measures in the Weddell Sea" aims at catching alive Antarctic toothfish and other endemic Notothenioids by means of baited traps to investigate their physiology, genetics, population structure and dynamics.
- The project "Piloting vertical longlines in support of the conservation and sustainable management of Antarctic toothfish (Dissostichus mawsoni) in the
Weddell Sea under CCAMLR" explores a novel, targeted approach to catch a limited amount (max. 5 tonnes) of toothfish for biological, genomic and ecophysiological research.
- YoPP AWImet-PS will, as contribution to the Year of Polar Prediction (YOPP) increase the rate of radio soundings on board Polarstern from 1 or 2 to 4 launches per day.
Chief scientistOlaf Boebel (Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research)
ProjectGEOTRACES -Trace elements and their isotopes in the water column
Cruise reportFS Polarstern PS117 (GApr12) cruise report polarstern_ps117.pdf (0.81 MB) 
Ocean/sea areas 
GeneralSouthern Ocean
SpecificZero meridian towards continent (Lazarev Sea) and Weddell Sea