Microplastic occurrence in brackish water ponds and milkfish in Capiz, Philippines

Abstract

This study was conducted to quantify and characterize microplastics in the water column, sediments, and milkfish ingestion from Pontevedra, Roxas, Ivisan, and Sapian ponds, aimed to provide a baseline report on microplastic pollution. Microplastic contaminants, such as fragments, pellets, and fibers, were extracted and analyzed from water samples, sediments, and fish tissues. Water column samples and sediments were collected from the field, and fish gills and gastrointestinal tracts were dissected in the lab for processing. The results showed varying levels of microplastic contamination across the four sites. Roxas exhibited the highest total particle count, with 109 particles. Roxas also had the highest microplastic contaminants in sediment samples, with 36 contaminants in 100g of sediment and an abundance value of 0.12 particles/g, mainly fibers and fragments. Pontevedra and Roxas recorded higher microplastic counts in fish gills, ranging from 68-77 particles (1.21-4.28 particles/g). Furthermore, Roxas had significant microplastic ingestion in the Milkfish gastrointestinal tract, with 66 particles (0.59 particles/g), mostly fibers. Site 2 showed higher contamination in tissue samples, with 62 microplastics (0.41 particles/g). Using One-Way ANOVA test, a significant differences were observed across all sites in water and sediment samples. The findings underscore the urgent need for aquaculture policies addressing microplastic pollution to mitigate its ecological impact on milkfish farming and associated human health risks.