Like most things in nature, benthic macroinvertebrates (the “bugs” that live in the streambed) require certain conditions in order for them to survive in their aquatic environment. Understanding their specific habitat requirements and tolerance to pollution, helps us understand the conditions of the stream.

We sample these bugs because they are quick and easy to sample due to their small size. They are excellent biological indicators as they live in the stream for a period of their life span and reflect impairments to water quality as they each have different pollution thresholds.

Some of these bugs can tolerate poor water quality, while some cannot. By knowing tolerance to pollution levels for these bugs, we can start to get an idea of stream health and apply that preliminary information to the entire health of the watershed.

We sample 35 sites each year in late spring to early summer using the Ontario Benthos Biomonitoring Network methodology. The goal of the program is to gather data on the health and habitat quality of streams within the Lower Trent region watershed. The results from the sampling give an indication as to the species composition at each site and therefore an understanding of the overall health of the watershed stream ecosystem.

This helps us pinpoint activities that are affecting habitat quality and gives us a starting point to work towards improvement.