Foraging hotspots and habitat use of Weddell seals (Leptonychotes weddellii) in the south-eastern Weddell Sea

Master Thesis subject (30 ECTS)
The marine region of the Filchner Trough located in the south-eastern Weddell Sea is characterized by the outflow of very cold, nutrient rich Ice Shelf Water originating from the Filchner-Ronne Ice Shelf. The outflow interacts with the Warm Deep Water of the Weddell Gyre circulation. The resulting hydrographic features are assumed to convert the Filchner region in a biological hotspot that shows enhanced productivity and corresponding abundances of marine top predators. Studies on the movements of southern elephant seals revealed that these animals travelled more than 2,000 nautical miles from their breeding site to reach the region of the outflow of the Filchner Trough. The seals remained there for several months while actively foraging. Enhanced occurrences of other seal species are expected to be concordant within the same region. The Weddell seal (Leptonychotes weddellii) in particular occupies this region perennially but information on its habitat use and foraging behaviour at this attractive feeding spot is scarce. Weddell seals were tagged with CTD-combined satellite-linked dive recorders during the interdisciplinary research expedition PS82 of RV Polarstern into the Weddell Sea in 2014. In the context of this Master thesis, the candidate will analyse the seals’ dive records in relation to the seal-borne hydrographic data, in order to gain knowledge about the vertical habitat use of this seal species. This shall give an insight into favoured foraging depths and hence also prey preferences and distribution. Additionally, the candidate will investigate the horizontal distribution of the satellite tagged Weddell seals in relation to known environmental conditions using a modelling approach, e. g. “maximum entropy” (Maxent). In this way suitable habitats shall be identified, which in turn would contribute to Germany’s recent initiative to propose a marine protected area (MPA) within the Weddell Sea.
This project has already been assigned to the student Dominik Andre Nachtsheim.
Number of students: 
academic year: 
Contact person email: 
contact person first name: 
Horst Bornemann
Other people involved: 
Prof. Dr. Claudio Richter Prof. Dr. Wilhelm Hagen PD Dr. Holger Auel Dr. Kerstin Jerosch Dr. Michael Schröder
Reference Number: RP-36102