Microplastics Interception from Riverine Ecosystems and Translocation to Fish Internal Organs

Area of Science:

• Environmental Science
• Ecotoxicology
• Aquatic Ecology

Background:

• Microplastics (MPs) are pervasive environmental contaminants in aquatic ecosystems.
• Understanding the pathways of MP uptake and accumulation in fish is crucial for assessing ecological risks.

Purpose of the Study:

• To quantify MP contamination in an urban river system.
• To investigate MP interception and organ-specific accumulation in the freshwater fish bleak (Alburnus arborella).
• To identify factors influencing MP translocation and distribution within fish.

Main Methods:

• Water column MP concentrations were measured.
• Six fish organs (GI tract, liver, kidney, muscle, brain, gonads) were analyzed for MP presence, concentration, shape, and size.
• Trophic ecology and MP morphology were correlated with accumulation patterns.

Main Results:

• Significant MP loads were found downstream of a metropolitan area and in all examined fish organs.
• The liver and kidney exhibited the highest MP concentrations.
• Trophic transfer was identified as a key route for MP uptake.
• Organ-specific MP translocation was observed, with size and shape influencing distribution (e.g., fibers in muscle, spheres in brain).

Conclusions:

• MP size and shape, along with fish feeding ecology, dictate MP interception and distribution.
• Smaller MPs represent a particular risk due to their potential to cross biological barriers.
• Findings highlight the need for field studies on MP bioaccumulation and long-term effects, incorporating MP morphology and ecological interactions into risk assessments.