Lower trophic level food web structure can be used as a metric of functional diversity and resiliency in an ecosystem. In AMBON, food web structure including phytoplankton, zooplankton, benthic invertebrates, and fishes is determined by using stable isotope analysis. We also aim to get a better understanding of the role of microbes within this food web. [AMBON scientists: Katrin Iken, Bodil Bluhm; research associate: Ann-Christine Zinkann]