Aquatic invertebrates have an important role in the ecological functioning of streams. They help break down organic matter such as woody debris which provide usable nutrients to other aquatic life. They eat microscopic plants, and are the primary source of food for fish and some birds, amphibians, and small mammals that live in the area.

Aquatic invertebrates include insects which live part of their life cycle in the water and crustaceans such snails, and crayfish.Aquatic invertebrates are being more extensively used by researchers as a way to monitor stream health. If water quality is poor, pollution sensitive invertebrates perish, while others which are pollution tolerant increase in numbers.

They are also sensitive to physical changes such as increases in siltation or water temperature. In addition, catastrophic events such as chemical spills can often be detected by a complete absence of stream invertebrate populations. By measuring the presence, absence and abundance of different species, habitat problems can often be detected.Invertebrate monitoring has been an on-going activity in Stoney Creek since 1997.  We use the protocol in the Streamkeepers Module 4.

We compare invertebrate populations between locations, season, and monitor changes in these populations over time. In the future, invertebrate sampling may also be used to monitor areas where periodic poor water quality has been reported. Click on the images below to see the participants in action: