Trophodynamics of Salps in the Atlantic Southern Ocean

• Main Author: Harbou, Lena von
• Other Authors: Bathmann, Ulrich, Hagen, Wilhelm
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universität Bremen 2010
• Subjects: salps; Salpa thompsoni; Ihlea racovitzai; Antarctica; zooplankton; grazer; gut fluorescence; gut pigment; fatty acid biomarker; 570; 570 Life sciences; biology; ddc:570; Antarctic; Lazarev; Lazarev Sea; Southern Ocean; Antarc*; IPY
• Online Access: https://media.suub.uni-bremen.de/handle/elib/2818; https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000119205

The impact of food regimes on the feeding dynamics, bioelemental composition and community structure of the two Southern Ocean salps Salpa thompsoni and Ihlea racovitzai are studied. During a mesoscale iron fertilisation experiment (EIFEX) in the Southern Ocean Polar Frontal zone, S. thompsoni showed an enhanced ingestion inside the fast developing bloom but a low degradation efficiency of the diatom rich food. Seasonal feeding dynamics of S. thompsoni and I. racovitzai were investigated during three surveys in the Lazarev Sea in summer, fall, and winter (LAKRIS and IPY 2007/2008). Pigment concentrations in the salp guts of both species showed significant positive correlation to ambient surface chlorophyll concentrations with high feeding activity of Ihlea racovitzai in winter. Ecological impacts of the salps grazing pressure and contribution to the vertical flux by the production of fecal pellets are discussed for both studies. Population structure and demographic development strongly suggest that blooms of both salp species are pulsed events of ephemeral duration in Antarctic waters.