300148 SE Food web ecology of aquatic ecosystems (2023W)

Material transfer and energy flow along food webs is central for the development of organisms. This course focuses on understanding the mechanisms that drive sources, movement, and function of dietary organic matter through aquatic food webs. Introducing the concept of trophic ecology (class 1-3), students will learn about the complexity of dietary pathways to organisms at various trophic levels, including transfer, metabolism, and accumulation of physiologically essential (e.g., trace elements and essential fatty acids), and potentially toxic (e.g., persistent organic pollutants and heavy metals) diet. An important block of this course (class 4-8) is devoted to dietary biomarkers: stable isotopes in terrestrial and autochthonous (aquatic) organic matter are used to indicate dietary sources of carbon (del13C), and nitrogen (del15N) as a marker of trophic relationships among organisms within aquatic food webs. Lipids and their constituent fatty acids are one of the major components of aquatic organisms and can also serve as dietary indicators of algal, bacterial, and terrestrial sources. In addition, new scientific insights from analytical biochemistry for the applicability of aquatic food web ecology will be presented and collaborated on during classes. Depending on the biochemical stability of contaminants, the concurrent investigation of diet biomarkers and bioaccumulation patterns of contaminants in aquatic organisms provides additional information of diet uptake success and its nutritional quality. In subsequent classes, students will be introduced to current challenges of pathways and mechanisms of aquatic energy flow, predator-prey interactions, community structure, and contaminant dynamics. This course provides integrative knowledge of how diet flow, if properly characterized, represents a metric of ecosystem health.