The higher up the tidal flat food chain, the more 'microplastic accumulation'... Inha University first proved

Tiny plastic particles are accumulating in higher concentrations in marine organisms at the top of the food chain, according to a groundbreaking study conducted by a team of researchers led by Kim Taewon and published in the international journal Environmental Science and Technology. The study, which focused on the coastal intertidal ecosystem in Incheon, South Korea, collected samples of seawater, sediment, algae, and 19 different species of intertidal organisms, including bivalves, crabs, sea urchins, and crustaceans.

The researchers categorized the collected organisms into four groups based on their feeding habits: filter feeders, sediment feeders, scavengers, and predators. They found that organisms further up the food chain, particularly predators, contained significantly higher concentrations of microplastics in their bodies. For instance, a single specimen of the predator gastropod, which fed on larger prey like barnacles and mussels, had approximately 4 times more microplastics than its filter-feeder prey.

Similarly, bivalves that consumed algae and other microorganisms had around 2.7 times more microplastics than the algae they fed on.

The researchers calculated the "biomagnification factor" (BMF), which measures the extent to which microplastics are transferred up the food chain and accumulated in top predators. The BMF for the studied organisms ranged from 3.9 to 9.6, indicating that predators may ingest up to 9.6 times more microplastics than their prey. The study also identified higher amounts of potentially harmful plastic materials, such as polyvinyl chloride (PVC), polyacrylonitrile (PAN), and epoxy resin, in scavengers and predators compared to filter feeders.

The significance of this research lies in its comprehensive analysis of the entire intertidal ecosystem, including seawater, sediment, and organisms, rather than focusing solely on microplastic concentrations in individual organisms. This approach provides a more accurate assessment of microplastic exposure and accumulation risks for organisms and highlights the varying levels of exposure depending on an organism's feeding habits and dietary preferences.

The study's findings emphasize the need to consider the specific characteristics of organisms and their feeding habits when evaluating the potential risks posed by microplastics in marine environments.