Benthic macroinvertebrates are small organisms that live on the bottom of streams, rivers, and lakes. They are useful as water quality indicators because they have relatively long lifespans and are sensitive to changes in the aquatic environment.
What Are We Monitoring?
Benthic macroinvertebrates can include insects, worms, mollusks, and crustaceans. Toronto and Region Conservation Authority (TRCA) collects benthic macroinvertebrates annually at more than 150 monitoring stations across the Toronto region.
Each invertebrate is identified to the species or family level.
Benthos data are collected in support of the long-term Regional Watershed Monitoring Program.
Data are also collected to support research studies, assess the impacts of development projects, evaluate habitat restoration projects, and guide environmental assessments.
Visit TRCA’s Open Data Portal to access the last 10 years of benthos data collected in TRCA’s nine watersheds.
What Are The Data Telling Us?
Benthic invertebrate communities remain stable in the majority of watersheds in the Toronto region.
The healthiest benthos communities are found in the headwater regions of the larger watersheds, while declines in benthos communities are more noticeable in smaller and more urbanized watersheds, such as Highland Creek.
Good news! Some sensitive benthos populations persist in the heavily urbanized Don River watershed, highlighting the importance and potential of continued conservation and restoration efforts.
Select the image below to view the Benthic Communities in Streams dashboard.
Visit TRCA’s Watershed & Ecosystems Reporting Hub
Contact
TRCA Watershed Planning and Ecosystem Science: wpes@trca.ca