A novel approach to tracing microplastics through the food web in seas

A modelling exercise tracing microplastics through the Black Sea food web can help assess future impacts of EU policies, including scenarios to reduce microplastics in marine ecosystems. The study can also help to track microplastics in marine food-webs globally.

The results showed that small benthic and pelagic primary consumers – organisms living respectively in the sea bottom and up in the water column–showed the highest concentrations of microplastics per unit of biomass. Secondary consumers, placed higher in the food web, were found to have greater concentrations through diet (biomagnification), compensated by lower environmental direct uptake.

The study, Ecotracer set up to trace microplastics up the Black Sea marine food web, was carried out by JRC scientists in collaboration with the US Penn State University and Luxembourg-based IT provider ARHS Developments S.A.

Microplastics threaten marine life in the Black Sea

Plastics account for 70% of litter at sea, and most of it breaks down into microplastics – particles small enough to be ingested by plankton and fish. The JRC developed the first Black Sea Ecotracer module to trace how these particles move through the ecosystem.

New model shows potential bioaccumulation and biomagnification

The model was calibrated using an extensive global database covering over 60,000 individual organisms across 780 marine species. Results show that small benthic and pelagic consumers such as shrimp, bivalves, anchovy, and sprat accumulate the highest concentrations of microplastics per unit biomass. Higher-level predators ingest microplastics mainly through diet, revealing signs of biomagnification.

Black Sea: a hotspot of plastic pollution

As a semi-enclosed basin, the Black Sea retains large amounts of floating plastics. Combined with overfishing, eutrophication, and invasive species, microplastics pollution poses an increasing threat to ecosystem health. This modeling approach allows policymakers to assess the risks and test future scenarios under EU initiatives such as the Zero Pollution Action Plan on reducing pollution to levels no longer harmful to health and nature by 2050, and the Biodiversity Strategy for 2030, a long-term plan to reverse the ecosystems degradation and protect nature.

A tool for future management

The Ecotracer module provides a calibrated baseline to explore how microplastic concentrations may evolve over time and space. By simulating ecological responses, it supports the design of evidence-based policies to reduce pollution and protect biodiversity.

Related links

Ecotracer set up to trace microplastics up the Black Sea marine food web

Marine Strategy Framework Directive

EU Zero Pollution Action Plan

EU Biodiversity Strategy for 2030