Lipids in key copepod species of the Baltic Sea and North Sea - implications for life cycles, trophodynamics and food quality

This thesis was embedded within the German GLOBEC project, which focused on climate induced ecosystem changes in the Baltic and North Sea by evaluating the influence of trophic interactions and physical forcing. Life-cycles and trophodynamics of the predominant copepod species Pseudocalanus acuspes, Temora longicornis and Acartia longiremis in the Bornholm Basin as well as the role of food quality for the reproductive success of copepods and higher trophic levels were examined. According to their general life-cycle characteristics the copepod species were categorized into three overwintering types, with different emphasis of storage lipids for overwintering. According to fatty acid markers in the storage lipids distinct interspecific and interseasonal differences were identified, reflecting different feeding strategies and a seasonal variation in food composition. Changes in the condition of copepods were discussed in light of their relevance for higher trophic levels.