Depok, January 6, 2026 – Microplastics have now become a serious threat to mangrove ecosystems. These microscopic plastic particles not only accumulate in sediments but can also enter the bodies of mangrove biota, potentially infiltrating the human food chain. The mangroves of Lampung Bay, which play vital ecological and economic roles as waste filters, coastal erosion barriers, and habitats for diverse organisms have been identified as a concentration hotspot for microplastics originating from both land-based and marine sources.
Responding to this issue, Berta Putri, a doctoral student in the Biology Program at the Faculty of Mathematics and Natural Sciences, Universitas Indonesia (FMIPA UI), conducted research to understand the characteristics and distribution of microplastics in the mangrove area. The results of her study are presented in a dissertation entitled “Characteristics and Distribution of Microplastics in the Mangrove Area of Lampung Bay,” which was defended during an open doctoral promotion examination for the Biology Doctoral Program at FMIPA UI. The session was chaired by Prof. Dr. Tito Latif Indra, S.Si., M.Si., as the head of the examination committee, and was held on Tuesday (January 6) at the Prof. Dr. G.A. Siwabessy Hall, FMIPA UI, Depok.
“This research demonstrates the complete pathway of microplastics entering the environment, accumulating in biota, and ultimately affecting microalgal communities, providing a holistic picture of the risks and dynamics of microplastics in the mangrove ecosystem of Lampung Bay,” Berta stated before the board of examiners.
Based on this research, Berta Putri successfully earned her doctoral degree with the distinction of very satisfactory, under the supervision of Prof. Dr. rer. nat. Drs. Mufti Petala Patria, M.Sc. as promoter, and Prof. Dr. Ir. Dietriech Geoffrey Bengen, DEA, along with Dr. Riani Widiarti, S.Si., M.Si., as co-promoters.
The study revealed striking findings: mangrove sediments contain significant amounts of microplastics, predominantly black and blue fibers, with polyethylene (PE) and polypropylene (PP) as the main polymer types. Large particles (>1,000 μm) were frequently detected, indicating that many originate from local activities such as textiles, fishing nets, and single-use plastics that have not yet degraded. This means that microplastics can accumulate within mangrove ecosystems, enter the bodies of animals, and potentially penetrate the food chain, posing a threat to both biota and human health.
“We also found that microplastics are not merely a physical pollution issue, but can alter ecosystem interactions, including microalgal communities that form the base of the mangrove food chain. These findings open up opportunities for more precise and sustainable management strategies,” Berta explained, highlighting the impacts of microplastics on mangrove ecosystems and their implications for sustainable environmental management.
Microplastics were also detected in the bodies of Telescopium telescopium and Geloina erosa, with distinct patterns corresponding to their respective feeding habits. T. telescopium predominantly ingests particles from sediments, while G. erosa ingests them from the water column. This makes both mollusks potential bioindicators of plastic pollution in mangrove ecosystems.
In addition, microplastics serve as a new substrate for epiphytic microalgae, known as the plastisphere. Although their abundance and diversity are lower than those found in sediments and the water column, diatom communities of the phylum Bacillariophyta remain dominant, particularly the genera Navicula and Nitzschia. These findings indicate that microplastics are not merely a physical problem but can also alter the structure of microbial communities in coastal ecosystems.
The research was conducted during the east monsoon (September–October 2022) and the west monsoon (May–June 2023), with sediment samples collected to a depth of 30 cm and water samples obtained using a plankton net. The results showed the highest microplastic abundance at Station 3 (Kota Karang, 1,260 particles/kg) and the lowest at Station 5 (Pulau Kelagian, 220 particles/kg). The highest levels in biota were also recorded at Station 3 during the east monsoon, reinforcing the link between human activities and microplastic contamination.
These findings are expected to serve as a scientific basis for sustainable mangrove management, the protection of biodiversity, and the health of coastal communities.
