Building on my previous work documenting causes and consequences of nutrient and fatty acid availability on functional traits in marine ecosystems, I will extend understanding of the processes that structure functional trait changes in marine ecosystems to the benefit of higher trophic levels. I will also examine the impacts of these fluctuations on the consumer growth and reproduction. This work will combine micro- and mesocosm experiments with subsequent fatty acid analyses to understand the effects of climate change on the production and transfer of energy and biomolecules through the food web and how such changes affect the productivity of ecosystems. Understanding changes in fatty acid production and transfer across tropic levels in not only of ecological relevance but is also important and of relevance for conservation and fisheries.