How do fish consume microplastics? An experimental study on accumulation pattern using Nile tilapia (Oreochromis...

Area of Science:

• Environmental Science
• Aquatic Toxicology
• Ecotoxicology

Background:

• Microplastic (MP) pollution is a growing concern in aquatic ecosystems.
• Understanding MP uptake and accumulation in commercially important fish species like Nile tilapia is crucial.

Purpose of the Study:

• To investigate microplastic exposure in Nile tilapia under controlled laboratory conditions.
• To identify the primary source, accumulation sites, and characteristics of microplastics in tilapia organs.

Main Methods:

• 150 Nile tilapia were exposed to different microplastic conditions in laboratory tanks.
• Fish organs (gastrointestinal tract, gills, muscles) were analyzed for microplastic presence, size, shape, and polymer composition using FTIR and FESEM.
• EDX analysis was performed to detect associated elements.

Main Results:

• Microplastics were predominantly accumulated from fish feed, not directly from tank water.
• The gastrointestinal tract showed the highest MP accumulation, followed by gills, then muscles.
• Polypropylene (PP) and polyethylene terephthalate (PET) were dominant polymers; associated elements like Ni, Cu, Zn, As, and Cd were detected.

Conclusions:

• Fish feed is a significant pathway for microplastic ingestion in Nile tilapia.
• MP accumulation varies by organ, with distinct size and shape profiles.
• The presence of potentially toxic elements alongside MPs warrants further investigation into health risks.