Sea silk, called the “golden fibre of the sea”, has often been the object of legends. Stories were told about how it was spun by mermaids. Fabrics woven from it were known to have been worn by emperors, popes, and other high-standing figures over the centuries as a symbol of wealth and power.
In actuality, sea silk was made from filaments, called byssus, secreted by pen shells like the Pinna nobilis to attach themselves to the seabed. This filament was worked upon by artisans along areas of the Mediterranean coast and made into a golden filament used in making a thin, shimmering fabric.
Pinna nobilis is a critically endangered species, and so in later centuries, this practice fell mostly out of use.
Now, a team of Korean researchers from POSTECH, led by Professor Dong Soo Hwang and Professor Jimin Choi, has recreated a fibre similar to the colour and texture of sea silk.
They used byssus not from the endangered Pinna nobilis, but from Atrina pectinata, a phylogenetically close relative clam cultivated in abundance for food along the Korean coasts.
The scientists found that the filaments from the Korean clams – so far seen as a marine waste – were physically and chemically similar to those of the Mediterranean ones, and processed it into a golden fibre resembling traditional sea silk
A. pectinata is a sustainable candidate for producing exquisite golden textiles and bioinspired pigments, the study Structurally Colored Sustainable Sea Silk from Atrina pectinata, published in the journal Advanced Materials, claimed.
While at work recreating sea silk, the researchers also hit upon the answer to the vexing question: From where does the sea silk get its golden glow?
The answer lies not in some special dye or a plant extract, but in the thread itself. The colour is created by a special phenomenon in which microscopic, round protein structures called “photonin” interact with light in a way that makes the fabric look iridescent.
This phenomenon is called structural colouration, and the light manipulation is similar to that of soap bubbles and butterfly wings.
The golden hue lasts for centuries and even millennia. “Structurally colored textiles are inherently resistant to fading. Our technology enables long-lasting color without the use of dyes or metals,” said study author Professor Dong Soo Hwang.
Due to high marine pollution and environmental decline, Pinna nobilis, the original source of sea silk, is heading towards extinction. The European Union has put a strict ban on the harvesting of this silk.
Moreover, only a very small number of artisans still remember the craft of harvesting and spinning the silk into fabric.
If the Korean experiment takes off, marine waste could be used to create a sustainable material that holds a heavy cultural and historical value. And open new possibilities for sustainable fashion and advanced materials.
(This article has been curated by Nityanjali Bulsu, who is an intern with The Indian Express.)
