Volunteers in northwestern Spain utilised strainers to sift through sand on Tuesday, gathering millions of minuscule plastic pellets known as nurdles that had washed up recently, posing a threat to wildlife.

These tiny pellets, also referred to as Mermaids' Tears, began appearing on the Galicia region's coast after six containers fell from a Liberia-registered ship on December 8 during its journey from Algeciras, Spain, to Rotterdam, Netherlands. According to shipping company Maersk, one of the containers carried bags filled with the pellets.

Measuring less than five millimetres in size, nurdles serve as the foundation for much of the world's plastic production. Despite their small size, they can be harmful to wildlife and are challenging to collect.

Non-governmental groups took the initiative to organise the cleanup, as volunteers used their own tools to collect the pellets. Ecologistas en Accion, one of the organising groups, criticised regional authorities for their perceived inaction, suggesting that collecting the pellets immediately after the container incident would have been more effective.

The pellets, if ingested by fish and birds, can be mistaken for food, leading to potential harm to the animals. Moreover, these plastic granules can find their way into the human diet.

The spill has primarily affected beaches in Vigo, Pontevedra, Noia, and La Coruna municipalities, but pellets have been discovered in neighboring regions of northern Spain. Environment Minister Teresa Ribera expressed uncertainty about the extent of the damage.

An investigation has been launched by Spain's state prosecutors into how the pellets arrived, sparking political tensions ahead of regional elections in Galicia.

The leftist government accused the region, led by the conservative Popular Party (PP), of delaying seeking help. Sumar, a hard-left party in the coalition government, filed a lawsuit against the Galicia regional government for alleged inaction.

Initially downplaying the risk, the Galicia government raised its pollution alert level to two on Tuesday, seeking assistance from the central government.

The political blame game continues, with the PP's national leader, Alberto Nunez Feijoo, criticising the leftist leaders for exploiting the situation.

In addition to the immediate environmental impact, the ingestion of plastic is harmful to human health, and nurdles can potentially bind chemical contaminants, increasing their toxicity.