A third of fish living in the coastal waters of the Pacific Island Countries and Territories are contaminated with microplastics, with rates reaching as high as 75 per cent in Fiji, according to new research.
The analysis, published in the open-access journal PLOS One by Jasha Dehm from the University of the South Pacific and colleagues, examined 878 coastal fish from 138 species caught by fishing communities in Fiji, Tonga, Tuvalu and Vanuatu.
Microplastic pollution is a global environmental and public health concern, yet little research has examined contamination in fish consumed across the Pacific. Despite their remoteness, Pacific Island Countries and Territories may be particularly vulnerable due to rapid urbanisation and limited waste and water management systems. Many coastal communities also rely heavily on fish for food, livelihoods and cultural practices.
Using published data from the Global Information Biodiversity Facility, the researchers found that around one third of sampled fish contained at least one microplastic particle, although contamination rates varied widely between countries. In Fiji, nearly three quarters of fish were contaminated, significantly higher than the global average of 49 per cent, while only five per cent of fish sampled in Vanuatu contained microplastics. Although contamination frequency was high in Fiji, the amount of plastic found in individual fish was generally low.
Two species — the thumbprint emperor (Lethrinus harak) and the dash-and-dot goatfish (Parupeneus barberinus) — were present in samples from all four countries and both showed higher levels of contamination in Fiji than elsewhere.
By analysing ecological traits such as diet, feeding behaviour and habitat, the researchers found that reef-associated and bottom-dwelling fish were more likely to contain microplastics than lagoon, coastal or open-ocean species. Fish that feed on invertebrates, use ambush feeding strategies or forage on the seabed were also more frequently contaminated.
The authors say the findings demonstrate the extent of microplastic pollution even in some of the world’s most remote marine environments. They suggest the higher contamination rates in Fiji may be linked to population density, coastal development and less effective waste management, and argue that understanding ecological risk factors could help identify the communities most exposed.
Jasha Dehm says: “The consistent pattern of high contamination in reef-associated species across borders confirms ecological traits as key exposure predictors, while national disparities highlight the failure of current waste management systems, or lack thereof to protect even remote island ecosystems.”
Dr Amanda Ford adds: “While microplastic levels in Pacific fish are generally lower than in many industrialised regions, Pacific communities rely far more heavily on fish as a primary protein source. Combined with major data gaps across the region, this makes locally generated evidence essential as Global Plastics Treaty negotiations advance and are translated into national policies.”
Dr Rufino Varea says: “Beyond the ecological insights, this study delivers a stark warning about the vulnerability of our food systems: we found that the reef-associated and bottom-feeding fish most accessible to our subsistence fishers are acting as reservoirs for synthetic pollution, particularly in Fiji, where nearly three-quarters of sampled individuals contained microplastics. The dominance of fibers in these samples challenges the assumption that marine litter is solely a visible, coastal management issue; it indicates a pervasive infiltration of textile and gear-derived contaminants into the very diet of our communities.
“This data shatters the illusion that our remoteness offers protection and provides the evidentiary basis we need to reject downstream solutions—such as recycling schemes—as insufficient. Instead, it compels us to demand a Global Plastics Treaty that enforces strict caps on primary plastic production and toxic additives, as this is the only viable way to safeguard the health and food security of Pacific peoples.”