Long-term effects of common fungicides on Australian amphipods

By Hung Vu

Allorchestes compressa.

Fungicides are used widely in agriculture to control fungal diseases and increase crop yield. After application, fungicides may travel off site via air, soil and water to ground and surface waters, therefore have the potential to contaminate aquatic environments.  Yet, relatively little is known about their potential effects on aquatic organisms. Amphipods are important in ecosystem services as they help with nutrient recycling through the decomposition of organic matter.  The long term effects of common fungicides on two Australian amphipod species, Allorchestes compressa and Austrochiltonia subtenuis were investigated in a CAPIM PhD project.

Amphipods are important in ecosystem services as they help with nutrient recycling through the decomposition of organic matter.

Juveniles of the marine amphipod A. compressa and the freshwater amphipod A.subtenuis were chronically exposed to two commonly used fungicides, Filan® (active ingredient boscalid) and Systhane™ (active ingredient myclobutanil) at environmentally relevant concentrations. A wide range of endpoints (stress responses) were measured that encompass different levels of biological organization including survival, growth, reproduction, and energy reserves (lipid, glycogen, and protein content). Long-term interaction effects of (combined) fungicides Filan® and Systhane™ on mature amphipod A. subtenuis were also investigated to evaluate how the results of mixture studies vary between endpoints.

Reproduction was the most sensitive endpoint and most affected by fungicide exposure

The study provides the first evidence of the effects of common fungicides on survival, growth, reproduction, and energy reserves of two Australian amphipods at environmentally relevant concentrations. Female amphipods were more sensitive to fungicides than males in terms of growth. Reproduction was the most sensitive endpoint and most affected by fungicide exposure. The effects of fungicide mixtures on A.subtenuis were endpoint-dependent and antagonistic effects were observed only on reproduction. The results suggest that fungicide pollution could affect the viability of amphipod populations in the natural environments. This could cause cascading effects on the ecosystem. Therefore, considering the long-term effects of fungicides in risk assessments for aquatic ecosystems is necessary.

Hung Vu submitted her PhD in June 2017.

References

Hung T. Vu, Michael J. Keough, Sara M. Long, and Vincent J. Pettigrove. 2016. Effects of the boscalid fungicide Filan® on the marine amphipod Allorchestes compressa at environmentally relevant concentrations. Environmental Toxicology and Chemistry 35:1130-1137.

Hung T. Vu, Michael J. Keough, Sara M. Long, and Vincent J. Pettigrove. 2017. Effects of two commonly used fungicides on the amphipod Austrochiltonia subtenuis. Environmental Toxicology and Chemistry 36:720-726.

Hung T. Vu, Michael J. Keough, Sara M. Long, and Vincent J. Pettigrove. 2017. Toxicological effects of fungicide mixtures on the amphipod Austrochiltonia subtenuis. Environmental Toxicology and Chemistry. DOI: 10.1002/etc.3809.