Why are benthos considered excellent indicators of stream flow?

Benthos, or the organisms that live on or in the bottom sediments of aquatic environments, are considered excellent indicators of stream flow primarily due to their biodiversity. A diverse range of species can indicate a healthy and varied ecosystem, which is often directly linked to stable and suitable flow conditions. Different benthic organisms have particular habitat requirements and sensitivities to environmental changes, including flow rates.

When stream flow is consistent, it supports a wider variety of habitats and organisms; on the other hand, significant changes in flow can lead to shifts in the community structure. Therefore, a diverse benthic community tends to be reflective of a balanced stream ecosystem that can adapt to environmental changes, including variations in flow. This connection underscores the importance of benthos in monitoring and assessing the health of stream systems.