Wastewater effluent affects behaviour and metabolomic endpoints in damselfly larvae

Area of Science:

• Environmental toxicology
• Aquatic invertebrate ecotoxicology
• Metabolomics

Background:

• Wastewater treatment plant (WWTP) effluents are significant sources of anthropogenic pollution in global aquatic environments.
• The effects of WWTP effluent on aquatic invertebrates, crucial components of freshwater ecosystems, remain poorly understood.

Purpose of the Study:

• To assess the behavioral and metabolic effects of WWTP effluent on damselfly larvae (Coenagrion hastulatum).
• To investigate the impact of effluent exposure on key fitness-related behavioral traits and physiological markers.

Main Methods:

• Larvae were exposed to various effluent dilutions (0, 50, 75, 100%) for one week.
• Behavioral assays measured activity, boldness, escape response, and foraging.
• Metabolomic analysis using targeted and non-targeted mass spectrometry identified changes in specific compounds.

Main Results:

• Effluent exposure significantly reduced larval activity and foraging behavior.
• A faster escape response was observed in exposed larvae.
• Metabolomic analysis revealed significant alterations in 14 compounds, indicating increased protein metabolism and oxidative stress.

Conclusions:

• WWTP effluent exposure adversely affects both behavioral and physiological traits in damselfly larvae.
• These sublethal effects suggest a greater potential threat to aquatic ecosystems than previously recognized.
• Combined behavioral and metabolomic assessments offer a robust method for detecting ecotoxicological impacts at multiple biological levels.