Kattner, G. Alfred Wegener Institute for Polar- and Marine Research, gkattner@awi-bremerhaven.de
Hagen, W. Institut fuer Polaroekologie, whagen@ipoe.uni-kiel.de

 
THE POTENTIAL OF FATTY ACIDS AS BIOMARKERS IN MARINE ZOOPLANKTON
 
The lipids of marine zooplankton are characterised by various lipid classes with a large variety of fatty acids and alcohols. Due to their unmodified transfer in the food web, specific lipid components may help to reveal dietary relationships. Herbivorous calanoid copepods are extremely rich in lipids, and their compositions can be strongly influenced by dietary lipids. For instance, lipids of copepods feeding on diatoms are dominated by the 16:1(n-7) fatty acid, whereas feeding on flagellates or Phaeocystis results in the prevalence of the 18:4(n-3) fatty acid. In feeding experiments the potential of fatty acids as trophic markers has been verified. Within about 6 weeks a dinoflagellate lipid signature was widely replaced by the characteristic diatom fatty acids. Calanoid copepods usually biosynthesise large amounts of wax esters rich in 20:1 and 22:1 fatty acids and alcohols. When ingested by predators these long-chain monoenes were partially accumulated in their lipids. However, the reflection of the diet in the lipid compositions of the next trophic level becomes more and more blurred with each step up the food chain.
 
Day: Thursday, Feb. 4
Time: 02:00 - 02:15pm
Location: Sweeney Center
 
Code: SS36TH0200S