Microplastics impair amphibian survival, body condition and function.

Area of Science:

• Environmental Science
• Ecotoxicology
• Amphibian Biology

Background:

• Microplastics (MPs) are pervasive environmental contaminants with largely unknown ecological risks.
• Amphibians face global decline, making their vulnerability to emerging pollutants like MPs critical to assess.

Purpose of the Study:

• To investigate the effects of microplastic exposure on tadpoles of the common midwife toad (Alytes obstetricans).
• To evaluate MP impacts on tadpole feeding, growth, body condition, and survival.
• To determine MP ingestion, egestion, and potential transfer through the food web via periphyton.

Main Methods:

• A microcosm experiment exposed tadpole populations to varying concentrations of fluorescent polystyrene microspheres (10-μm).
• Assessed tadpole feeding, growth, and body condition.
• Quantified MP ingestion and egestion using fluorescence, and analyzed MP presence in periphyton.

Main Results:

• Microplastics significantly affected tadpole feeding, growth, and body condition across tested concentrations.
• Tadpole mortality occurred at the highest MP concentration.
• Fluorescence confirmed MP ingestion by tadpoles, presence in faeces, and attachment to periphyton, impacting periphyton growth.

Conclusions:

• Microplastics represent an additional significant stressor for amphibians, alongside other known threats.
• Amphibians can act as a crucial pathway for microplastic transport from aquatic to terrestrial ecosystems.