Microplastic pollution threatens marine ecosystems, especially in vulnerable regions like the Pacific Islands. This study examines temporal trends by comparing Anadara spp. specimens from Fiji's tidal flats in the 1980s and 2023–2024. Historical samples from the University of the South Pacific's Marine Collection and newly collected specimens were analyzed. Results show microplastic contamination increased from 76 % of 1980s samples (0.42 ± 0.4 particles per individual) to 100 % in 2023–2024 (0.93 ± 0.4 particles per individual). Fragments and films became more prevalent, indicating diversified pollution sources. Contamination shifted from concentrated in Laucala Bay (1980s) to evenly distributed across sites, likely due to urban expansion. This study highlights the value of historical data for understanding long-term trends and calls for targeted mitigation strategies to address localized pollution sources.
