Abstract:
Taal Lake, the third largest lake in the Philippines, is a freshwater ecosystem of
significant importance for the country's fisheries sector and diverse fish species.
However, the lake faces significant environmental challenges, particularly pollution
caused by persistent plastics that degrade into microplastics (MPs). This pollution poses a
potential threat to Sardinella tawilis, an endemic species of the lake and the only
freshwater sardine in the world, as they are susceptible in ingesting MPs. The objective of
this study is to assess the presence of MPs in the gastrointestinal tract of Sardinella
tawilis and characterize them based on size, shape, and color. Fish samples were
collected from three sites (Mataasnakahoy, San Nicolas, and Santa Teresita) and
subjected to digestion, filtration, and stereomicroscopic visualization. Statistical tests
were applied for data analysis. All 30 samples tested positive for MPs, with the highest
abundance found in Sardinella tawilis samples from Santa Teresita. The ingestion of MPs
by Sardinella tawilis did not show a preference for specific MP length but exhibited a
higher preference within a narrower width range. The most prevalent MP shapes were
fibers. Black and blue were the most abundant colors detected. These findings suggest
potential sources of MPs in Taal Lake, including anthropogenic activities such as
agriculture, leisure, and fishing practices, as well as consumer products like synthetic
textiles, tires, and cosmetics. The findings of this study raise significant concerns about
the potential impact on human health in the area due to the high prevalence and
consumption of Sardinella tawilis. This increases the likelihood of MPs being
bioavailable to humans and highlights the potential consequences of their exposure.
