Macroinvertebrates are animals without backbones that are large enough to see without the need for equipment. These organisms can serve as bioindicators in waterways and monitoring macroinvertebrate populations is often used to assess the quality of rivers and streams. This simulation can be used to simulate water quality monitoring or to calculate biodiversity. The resources page has a river quality index activity available, as well as biodiversity quantification. Google Doc versions of these resources are also available on Google Drive.