“Nurdles” may sound cute but they pose a huge risk to the marine environment. Also known as “mermaid tears”, these small plastic pellets are a feedstock in the plastic industry. Instead of being converted into household items, many end up in the ocean, collecting toxins on their surfaces and being eaten by marine wildlife. Not so cute now, are they?

Nurdles are the building blocks for most plastic goods, from single-use water bottles to televison sets. These small pellets–normally between 1mm and 5mm–are classed as a primary microplastic alongside the microbeads used in cosmetic products–they’re small on purpose, as opposed to other microplastics that break off from larger plastic waste in the ocean.

The small size of nurdles makes them easy to transport as the raw material which can be melted down and moulded into all kinds of plastic products by manufacturers. Unfortunately, mismanagement of these little pellets during transport and processing leads to billions being unintentionally released into rivers and oceans through effluent pipes, blown from land or via industrial spillage.

An ocean of mermaid tears

“Mermaid tears” is an appropriate nickname when we consider the potential harm that nurdles have on marine life. Their small size, round shape and array of colours make them attractive food–easily mistaken for fish eggs and small prey. This “food” has an extra problem–it comes with a side of noxious chemicals.

The large surface area to size ratio and polymer composition of the nurdle pellets allow persistent organic pollutants (POPs) in seawater to build up on their surfaces. These toxins then transfer to the tissue of organisms which eat them. The problem is in the name–POPs are “persistent”, meaning they don’t go away easily and can remain on the surface of nurdles for years.

Nurdles can also be colonised by microbes that are dangerous to humans. A study investigating nurdles on bathing beaches in East Lothian, Scotland, found that all five beaches tested had nurdles that were covered with E. coli–the bacterium responsible for food poisoning.

Nurdles can be so noxious that people cleaning beaches or recording pellets in scientific surveys are advised not to touch them with their bare skin–which makes sun bathing on many beaches in the summer an unattractive prospect.