Microplastic ingestion by adult milkfish Chanos chanos (Forsskål, 1775) in aquaculture system: The case of Butuan Bay, Philippines.

The Philippines is an archipelago that relies on marine resources. Butuan Bay in the Philippines supports aquaculture, which can contribute to and can be impacted by plastic pollution. However, the microplastics (MP) in milkfish, an important aquaculture species in the area, are yet to be ascertained. This study determined the prevalence of microplastics in the surrounding seawater and in the gut of adult milkfish from cages in Butuan and Nasipit in Butuan Bay. Water samples in Nasipit and Butuan contain 0.20 items/L and 1.00 items/L, respectively. MPs in milkfish in Butuan (10.27 items/individual) were significantly higher than in Nasipit (5.40 items/individual). A total of 235 MPs in 29 out of 30 fish samples (97 %) from the two sites were detected. The dominant MP shape and color were fiber and blue, respectively. The presence of microplastics in the milkfish may indicate a possible risk to the fish species and human health.

Microplastics in surface water of Laguna de Bay: first documented evidence on the largest lake in the Philippines.

The pollution of aquatic systems by microplastics is a well-known environmental problem. However, limited studies have been conducted in freshwater systems, especially in the Philippines. Here, we determined for the first time the amount of microplastics in the Philippines' largest freshwater lake, the Laguna de Bay. Ten (10) sampling stations on the lake's surface water were sampled using a plankton net. Samples were extracted and analyzed using Fourier-transform infrared spectroscopy (FTIR). A total of 100 microplastics were identified from 10 sites with a mean density of 14.29 items/m3. Most microplastics were fibers (57%), while blue-colored microplastics predominated in the sampling areas (53%). There were 11 microplastic polymers identified, predominantly polypropylene (PP), ethylene vinyl acetate copolymer (EVA), and polyethylene terephthalate (PET), which together account for 65% of the total microplastics in the areas. The results show that there is a higher microplastic density in areas with high relative population density, which necessitates implementing proper plastic waste management measures in the communities operating on the lake and in its vicinity to protect the lake's ecosystem services. Furthermore, future research should also focus on the environmental risks posed by these microplastics, especially on the fisheries and aquatic resources.