What does biomonitoring primarily test for?

Biomonitoring primarily tests for effluent toxicity because it involves assessing the biological responses of aquatic organisms to the presence of contaminants in a water body, particularly those that can affect the health of living organisms. This process can help determine the overall health of an ecosystem and identify toxic substances that may be present in wastewater discharges.

The methodology often includes exposing specific organisms to water samples and observing their health, growth, reproduction, and survival rates. By focusing on living organisms, biomonitoring provides a comprehensive understanding of the potential hazards that might not be evident from chemical analyses alone. This is crucial for evaluating the impact of effluents on the receiving environment and ensuring compliance with environmental regulations.

While aspects like water clarity, pH levels, and heavy metals can be important indicators of water quality, they do not fully encompass the biological effects of wastewater discharges as effectively as testing for effluent toxicity does.