Waikato Regional Council monitors river biology to determine the ecological health of rivers and streams in the Waikato region. Fish tell us more about habitat and water quality, as well as about how well migratory native fish can get access to streams from the ocean. Invertebrates are a key part of the biodiversity of all rivers and streams. They also form an important part of the food chain in rivers and streams, and can influence habitat quality by filtering water, churning up sediments and breaking down organic material. Invertebrates are medium term indicators of stream health and integrate conditions over time prior to sampling. River biology is therefore less affected by small rainfall events than traditional water quality parameters such as faecal coliforms or E. coli which vary temporally in relation to rainfall.
Waikato Regional Council’s stream invertebrate monitoring programme:
The invertebrate sampling shows us that ecological health of streams and rivers is better in some parts of the Waikato region than in others. This is mainly because of the greater intensity of land use in parts of the region with large areas of lowlands and developed hill-country.
More detail on this indicator, including how and where Waikato Regional Council collects this information, is available in the Technical Information page.
The United States Environmental Protection Agency (external link) website provides information on rapid bioassessment protocols for use in streams and wadeable rivers.
This indicator is updated every three years
Aquatic Ecologist (invertebrates) - Science and Strategy Directorate