"Resolving trophic interactions and energy channels in marine and aquatic ecosystems using amino acid isotope analysis"
Talk Summary: Ecosystems are connected by reciprocal transfer of nutrients and energy. These “nutrient subsidies” move across ecosystem boundaries, for example, from the ocean to the shore or between lakes and surrounding land, and they play a key role in supporting primary and secondary production. In nutritional symbioses, such as corals and their endosymbiotic algae, nearshore production in the form of zooplankton can serve as a critical subsidy supporting animal hosts during periods of physiological stress. Yet, quantifying the role of nutrient subsidies and shifts in animal diets has been challenging due to limited resolution and high spatiotemporal variability at the base of the food web and among dietary sources. A newer approach, compound-specific isotope analysis (CSIA) of amino acids, provides sharper insights into diets and energy pathways. In this seminar, I will present findings from my research on coral reefs (symbiotic reef corals and predatory fish and sharks) and mountain lakes (zooplankton) showing how CSIA helps us understand the flexibility of animal diets and the ways they tap into different energy channels. Ultimately, these insights reveal how nutrient subsidies shape biomass production across ecosystems and highlight the environmental, physiological, and behavioral factors driving trophic plasticity and niche partitioning in both free-living and symbiotic animals.
Coffee and snacks provided!