Microplastic Pollution in Aquatic Ecosystems

Microplastics—synthetic polymer fragments smaller than 5 mm—have emerged as pervasive contaminants in rivers, lakes, estuaries and the open ocean. They originate from the breakdown of larger plastic debris, abrasion of synthetic textiles, personal care products and industrial processes. Once released, buoyancy, fluvial transport and ocean currents govern their dispersal, leading to accumulation in surface waters, deep-sea sediments and coastal depositional zones. Microplastics interact with organic pollutants through sorption processes, become ingested by plankton, invertebrates and fish, and can interfere with feeding behaviour, growth and reproduction. Through trophic transfer, microplastics and associated chemicals may reach higher predators and, ultimately, humans via seafood consumption. The environmental fate of these particles is influenced by biofilm formation, aggregation with natural particles and sedimentation, creating complex sinks and pathways that challenge monitoring efforts. Global modelling of riverine fluxes, combined with field surveys, has provided baseline estimates of inputs and hotspots, but large uncertainties remain. Mitigation strategies now hinge on improved waste management, novel capture technologies and standardised analytical methods to quantify microplastics across diverse water bodies. Addressing this issue demands an interdisciplinary approach spanning hydrology, ecology, chemistry and public policy to safeguard aquatic ecosystems and human health.

Research from Nature Portfolio

Recent modelling efforts have quantified the magnitude and seasonality of plastic inputs from major rivers into the marine environment, revealing that a handful of catchments contribute the majority of global flux. Advances in sample preparation have enabled the enzymatic digestion of biota-rich seawater, improving detection of microplastics without degrading polymer particles and facilitating more accurate abundance estimates in productive waters. Investigations of seafood sold for human consumption have demonstrated the ubiquity of plastic fibres and fragments in commercially important fish and shellfish, highlighting differences in polymer types linked to regional waste management practices and raising questions about potential human exposure through diet.

Microplastic Pollution in Aquatic Ecosystems publication trend

The graph below shows the total number of articles in microplastic pollution in aquatic ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Microplastics: Synthetic polymer particles smaller than 5 mm in any dimension.

Sorption: The process by which chemical contaminants adhere to or are absorbed by plastic surfaces.

Bioaccumulation: The net accumulation of substances, such as microplastics or associated pollutants, within an organism over time.

Trophic transfer: Movement of contaminants through food webs, from prey to predator.

Enzymatic digestion: Use of specific enzymes to break down organic matter in samples, preserving microplastic particles for analysis.

References

1. River plastic emissions to the world’s oceans. Nature Communications (2017).
2. Microplastics in the aquatic and terrestrial environment: sources (with a specific focus on personal care products), fate and effects. Environmental Sciences Europe (2016).
3. A global inventory of small floating plastic debris. Environmental Research Letters (2015).
4. The deep sea is a major sink for microplastic debris. Royal Society Open Science (2014).
5. Microplastics in freshwaters and drinking water: Critical review and assessment of data quality. Water Research (2019).
6. Isolation of microplastics in biota-rich seawater samples and marine organisms. Scientific Reports (2014).
7. Anthropogenic debris in seafood: Plastic debris and fibers from textiles in fish and bivalves sold for human consumption. Scientific Reports (2015).