Greece has called on an ally from the deep to see how polluted its crystal clear seas have become: 'It leaves you speechless'
A diver collects mussels from the bottom of the sea in order to test them, PHOTO: AA / Abaca Press / Profimedia Images
Overtourism and heavy maritime traffic in the Mediterranean are contributing to increased pollution of Greece's azure waters, say Greek scientists who have placed thousands of mussels on the seabed to help detect microplastics.
Mussels – filter organisms that absorb a wide range of contaminants into their tissues, including invisible microplastics – have been used for decades around the world as a barometer of marine pollution.
Researchers at the Hellenic Center for Marine Research (HCMR) are using them in Greece, a country whose pristine beaches and clear waters attract millions of tourists every year.
In May, they dived mussel cages at various depths and locations in Greece and beyond – from busy harbors to isolated islands. In September, they recovered them to analyze the particles accumulated by the mussels. To test the surface water, I use a floating device with a net.
“It's mind-blowing that, over a distance of just two kilometers, you can collect all these tiny microplastics,” said oceanographer Argyro Adamopoulou of the HCMR laboratory, referring to the samples collected with the water-filtering net.
The warning issued by researchers in Greece
Scientists warn that the entire Mediterranean Sea, a semi-enclosed basin, has become a “hotspot” of microplastic accumulation.
The particles recovered in Greece varied in shape – from fragments to films, microfibers or granules – and were mostly blue or transparent. HCMR biologist Nikoletta Digka says this is an indication that the particles came from single-use plastics such as garbage bags and water bottles.
Over time, they are shredded by waves, currents and exposure to the sun, becoming increasingly difficult to detect.
Digka pointed out that although the concentrations are not yet high enough to be harmful to humans, microplastics are present in every species analyzed so far by the research team.
“On average, we find one or two microplastics per population analyzed,” Digka said, warning that without action, continued fragmentation will increase the amount of microplastics ingested by marine organisms, increasing the risk to humans.
