The project is aimed at understanding the seasonal variation in dominant zooplankton and fish larvae species and foodweb changes using stable isotopes isotope techniques and amino acid analysis. Variation in the amino acid composition and the stable isotopes signal provides a good estimate of the variation in trophic dynamics in marine zooplankton. Samples for zooplankton and phytoplankton is already being taken, so this particular project part aims at sampling fish larvae in the Baltic coastal area (B1 station).

The main aims of this PhD study is to investigate the effect of phytoplankton species composition on energy (carbon) and nutritional transfer efficiency to terminal zooplankton consumers at
(i) dominance of large and high-food quality phytoplankton,
(ii) dominance of phytoflagellates, and
(iii) enhanced bacterial production.
This will be tested in laboratory, mesocosm and field experiments with natural phytoplankton, microzooplankton composition and specially focusing on zooplankton. The aim is to test the overall prediction that phytoplankton community structure and species composition are key regulators of energy and food quality transfer across trophic levels.

Stockholms universitet, institutionen för systemekologi

Jens Nielsen, doktorand,
Monika Winder, forskare och handledare,
Alfred Burian, doktorand,
Anna-Lea Golz, examensarbetare