PROJECT
Development and Application of an Indicator for Monitoring the State of the St. Lawrence River Using Benthic Communities

Program: Monitoring the State of the St. Lawrence

Objective

The aim of this project is to develop a benthos-based indicator for monitoring the state of the St. Lawrence River using the method of the National Water Research Institute’s Canadian Aquatic Biomonitoring Network (CABIN) (Environment Canada – Ontario Region).

Useful for Environmental Monitoring

Benthic invertebrates are organisms like insects, molluscs, crustaceans and worms that live on water bottoms on bedform surfaces, in soft sediment or even on plants. These creatures have been used for decades to evaluate the state of health of aquatic ecosystems because of their biological characteristics. They are easy to sample, their taxonomy is well known and their sedentary nature makes them ideal for detecting local sources of contamination and revealing the effects of point-source or chronic contamination.

The distribution and composition of benthic communities are influenced by multiple environmental factors, including substrate type, current speed, the presence or absence of aquatic vegetation and the physical and chemical characteristics of the environment. The CABIN method is based on the reference-condition approach, in which the benthic invertebrate community and biophysical conditions at a given test site are measured and compared to reference sites undisturbed by human activities. The degree of dissimiliarity between the test sites and the reference sites is an indicator of the state of the environment.

A Pilot Project in Lake Saint-Pierre

Since 2004, a team of scientists from Environment Canada has been working in collaboration with the Groupe de recherche interuniversitaire en limnologie (GRIL) to study the composition and spatial distribution of the benthic communities in Lake Saint-Pierre using the CABIN method. Work is ongoing to advance knowledge of the influence of the environment on these communities, with the aim of determining if they can serve as valid indicators for monitoring the state of Lake Saint-Pierre and, eventually, an ecosystem as vast as that of the St. Lawrence.

Related Links

Info St. Lawrence – Biological Resources
Benthic Invertebrates: New Indicators for Monitoring the State of Lake Saint-Pierre

Canadian Aquatic Biomonitoring Network (CABIN)