Abstract
We propose a novel biochemical approach to study the constraints on secondary production in aquatic food webs with autotrophic and detrital resource bases. Our main objective is to quantify the importance of polyunsaturated fatty acids (PUFA) for the trophic transfer efficiency in aquatic food webs of different lake types. We combine and develop our research experience on food quality and trophic interactions in pelagic (TV) and benthic (WG) food webs. We propose a combination of field studies and laboratory experiments to address the following two specific questions: 1) What is the natural variation in resource and consumer fatty acid content in lakes across gradients in nutrients and allochthonous carbon?, and 2) How does the PUFA content of food affect the trophic transfer efficiency across the plant-consumer interface? These studies will be performed using well established methods. The proposed project will significantly extend the current knowledge about and understanding of patterns in PUFA distribution in aquatic habitats and their importance for trophic transfer, which is a fundamental ecosystem process. The project contributes to our capacity to predict ecological effects of disturbances, and adds to the scientific knowledge basis that is required for sustainable management of aquatic ecosystems.
Sweden