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Bugs in the bubbles

Bugs in the bubbles. What can they tell us?

By Watershed Planning & Restoration | The Watershed Watch

Unlike fish and other more mobile animals, aquatic macroinvertebrates (a.k.a. bugs) cannot move away from polluted waters. Most have an annual life cycle, but some larger species can spend up to five years as larvae living under water. By taking one sample of a macroinvertebrate community, biologists are potentially compiling at least a year’s worth of water quality data.

Among the different species there is a wide range of tolerance to pollutants; some are very sensitive and cannot survive changes in their environment, while generalists can adapt more easily. The presence and/or absence of certain bugs provides a clear picture of the overall health of the stream ecosystem. For example, finding stonefly macroinvertebrates is a very good sign! Found under rocks in swiftly flowing cool water, they’re an indicator of excellent water quality.

Through ongoing monitoring, changes in the aquatic bug community can determine if pollutants are widespread in the waterbody, as well as what those pollutants might be.