Electronic Theses and Dissertation

Penelitian ini bertujuan untuk mengidentifikasi kelimpahan, jenis, dan ukuran mikroplastik serta menganalisis karakteristik sedimen di kawasan Taman Wisata Alam (TWA) Pulau Weh, Sabang. Pengambilan sampel dilakukan pada enam stasiun menggunakan metode purposive sampling. Identifikasi mikroplastik dilakukan melalui pemisahan densitas menggunakan larutan NaCl jenuh, destruksi bahan organik menggunakan KOH, dan pengamatan menggunakan mikroskop stereo, sedangkan karakteristik sedimen dianalisis dengan metode ayakan kering berdasarkan klasifikasi Folk dan parameter statistik sedimen (mean size, sorting, dan skewness). Hasil penelitian menunjukkan rata-rata kelimpahan mikroplastik sebesar 33,89 partikel/kg dengan total 61 partikel, dan seluruh mikroplastik yang ditemukan hanya berupa fiber. Kelimpahan tertinggi ditemukan di Stasiun Rubiah 2 sebesar 60 partikel/kg, sedangkan terendah di Stasiun Seulako sebesar 10 partikel/kg. Dominasi mikroplastik jenis fiber diduga berkaitan dengan aktivitas perikanan dan wisata bahari, seperti degradasi jaring, tali tambang, senar pancing, dan tali perahu akibat paparan sinar matahari, abrasi, serta gesekan mekanis di lingkungan perairan. Tidak ditemukannya jenis fragmen, film, maupun pelet diduga disebabkan oleh rendahnya masukan limbah plastik padat di lokasi penelitian, dominasi sedimen berpasir, serta kondisi hidrodinamika yang menyebabkan partikel tersebut lebih mudah tertransport dibandingkan fiber yang berbentuk memanjang sehingga lebih mudah terperangkap di sela-sela butiran pasir. Ukuran mikroplastik berkisar antara 200,51–593,19 µm dan didominasi oleh ukuran 300–500 µm, sedangkan sedimen pada seluruh stasiun didominasi oleh fraksi pasir (82,51–98,43%) dengan tipe sedimen pasir dan pasir berkerikil. Analisis regresi menunjukkan bahwa hubungan antara karakteristik sedimen dengan kelimpahan maupun ukuran mikroplastik tergolong lemah hingga sangat lemah dan tidak signifikan secara statistik (p > 0,05), sehingga distribusi mikroplastik di kawasan TWA Pulau Weh lebih dipengaruhi oleh sumber pencemar dan aktivitas antropogenik dibandingkan karakteristik tekstur sedimen.

Kata kunci: Mikroplastik, fiber, sedimen, Taman Wisata Alam Pulau Weh, Sabang.

This study aimed to identify the abundance, type, and size of microplastics and to analyze sediment characteristics in the Taman Wisata Alam (TWA) Pulau Weh, Sabang. Sediment samples were collected from six stations using a purposive sampling method. Microplastics were identified through density separation using a saturated NaCl solution, organic matter digestion with KOH, and observation under a stereo microscope, while sediment characteristics were analyzed using the dry sieving method based on the Folk classification and sediment statistical parameters (mean size, sorting, and skewness). The results showed an average microplastic abundance of 33.89 particles/kg, with a total of 61 particles, and all identified microplastics were exclusively fibers. The highest abundance was recorded at Rubiah 2 Station (60 particles/kg), while the lowest was found at Seulako Station (10 particles/kg). The dominance of fiber microplastics is presumed to be associated with fishing and marine tourism activities, particularly the degradation of fishing nets, ropes, fishing lines, and mooring ropes due to sunlight exposure, abrasion, and mechanical wear in the aquatic environment. The absence of fragments, films, and pellets is likely attributable to the low input of rigid plastic waste in the study area, the dominance of sandy sediments, and hydrodynamic conditions that facilitate the transport of these particle types, whereas elongated fiber particles are more easily trapped within the interstitial spaces between sand grains. Microplastic sizes ranged from 200.51 to 593.19 µm, with the 300–500 µm size class being the most dominant. Sediments at all stations were dominated by sand fractions (82.51–98.43%) and classified as sand and gravelly sand. Regression analysis indicated that the relationships between sediment characteristics and both microplastic abundance and size were weak to very weak and statistically insignificant (p > 0.05), suggesting that the distribution of microplastics in the TWA Pulau Weh area is influenced more by pollution sources and anthropogenic activities than by sediment textural characteristics. Keywords: Microplastics, fibers, sediment, Weh Island Nature Tourism Park, Sabang.