Undergraduate thesis (BS in Biology) -- Foundation University, 2026.

Includes bibliographical references and appendixes.

ABSTRACT
Microplastics are emerging pollutants detected in freshwater ecosystems worldwide,
however, data remain limited in protected areas in the Philippines. This study aimed to determine
the occurrence, abundance, and characteristics of suspected microplastics in surface water
collected from Bayawan Nature Reserve, Bayawan City, Negros Oriental. Surface water samples
were collected in three replicates from upstream, midstream, and downstream sections and
processed through vacuum filtration. Suspected microplastics were identified using
stereo microscopy and hot needle testing. These particles were characterized based on size, shape,
and color, and their abundance was expressed in particles per liter (particles/L). A total of
seventy-eight (78) suspected microplastics were identified across all sampling stations.
Microplastics were observed in all sites, indicating their presence in the study area. Fibers and
fragments were the dominant forms, while white and blue were the most common colors.
Variations in abundance were observed among sampling stations, which may be influenced by
environmental conditions and nearby human activities. Polymer characterization using Raman
spectroscopy yielded match scores ranging from 0.15 to 0.30, which are below the accepted
threshold for reliable identification. Therefore, polymer composition remains inconclusive.
Despite thís limitation, the presence of suspected microplastics highlights potential
contamination in freshwater systems, even within protected areas.
Keywords: microplastics, surface water, freshwater ecosystem, Bayawan Nature Reserve,
Philippines