This activity is based on the fieldwork of ecologist Dr. Mary Power. Students explore the nature of trophic relationships in an aquatic ecosystem by first measuring the biomass of algae and then estimating the number of fish that could be supported based on their understanding of trophic pyramids. They discover that biomass pyramids can be inverted in aquatic ecosystems and then they work with productivity rates to realize that the trophic pyramids are a conventional shape when productivity is integrated over time. Finally, they use authentic field data to determine the relationship between sunlight and biomass in river pools.
This resource was built on interactive platform with multiple pathways through the interactive. The learning outcomes are always the same, but the data can differ slightly, depending on the river pools selected by the students. The resource keeps track of student progress and outputs a PDF report that contains all their work and responses to the questions.