Samples taken from four beaches over a few months yielded a total of 10,705 nurdles, with one particular day in November turning up 1,000 of the lentil-sized pieces of plastic.

Nurdles are the raw materials used by the plastic industry, and accidental spills and mishandling result in millions of the pellets – which measure less than 5mm across – getting washed into the sea.

Because they are so light, they travel great distances and get washed up onto the shore.

They accumulate on the surface of sand, but they are not just litter: the micro-resin pellets are also an environmental menace, as they eventually break down with wave action, getting smaller and smaller and working their way into the food chain.

Unfortunately, there is very little information available on the scale of the problem in Malta, even though the Marine Framework Strategy Directive obliged EU member states to monitor marine litter and its impact on the food chain.

This is one reason a team spearheaded by Adam Gauci, from the Physical Oceanography Research Group, came together to draw up an algorithm capable of registering the quantity, colours and sizes of the pellets.

One of the team – John Montebello, a student at the Institute of Earth Systems – spent many hours between August and November 2017 sifting through a 50cm x 50cm grid, roughly the size of a chair seat, to a depth of 5cm.

Samples were taken from Għajn Tuffieħa Bay, Golden Bay, Għadira and Pretty Bay, with eight visits to each beach, and samples taken from the same locations.

“We soon learned that asking tourists to reposition themselves out of the way is really uncomfortable. Asking a local even more so. A few awkward encounters later, we shifted our sampling schedule to very early in the morning, before swimmers arrived and prior to beach cleaning,” one of the team said.

Source: Nurdlehunt.org.co.uk

It was no surprise that Għajn Tuffieħa – which churned up 6,307 pellets ­– was the most polluted, as it faces the prevailing north west winds and waves. But he was surprised to find 1,000 in one sample taken a year ago.

Golden Bay only yielded 2,807 pellets – perhaps because the beach’s breadth meant nurdles washed ashore were spread over a larger area, he surmised.

Pretty Bay also had low numbers – just 1,102 – which may be due to its alignment and the fact that it is also relatively deep.

The least polluted was Għadira, where 489 nurdles were found, almost certainly because it does not face the prevailing seas.

Mr Montebello discovered there were far fewer nurdles in summer, which may be due to them being trampled into the sand by visitors, their removal by beach cleaning, or simply less wind and waves.

But for a scientist, these questions beg to be answered, and Mr Montebello will challenge many of the hypotheses as part of his masters in geosciences.

Sampling will start again in December and will continue every three months.

“We are very fortunate because awareness about plastic is really growing. But we need information if we are to monitor trends,” he said.

“At least we have made a start.”

In the meantime, what can be done to reduce the pollution?

Not much on a macro-scale, as the nurdles are too small to be picked by beach-cleaning equipment and are only removed by chance. But as he tucked the handful he had collected into his pocket, he looked around the bay, which was dotted with tourists enjoying a dip.

“Imagine if each person spent a few minutes removing the ones around their towel... every little bit counts in this fight.”

Plastic pieces

• Approximately 27 million tonnes of nurdles are manufactured annually in the United States alone.

• Creatures that make up the base of the marine food chain, such as krill, are often killed when choking on nurdles.

• Nurdles have frequently been found in the digestive tracts of various marine creatures.

• The pellets absorb micropollutants from the seawater.