<p>This photograph shows a remnant of a bygone era, when the wealthy in <a href="https://www.deccanherald.com/india/goa">Goa</a> used shells to cover windows without blocking light. The material behind it—the capiz shell—is finding renewed relevance today, as a subject of scientific and environmental interest.</p>.<p>Derived from the marine bivalve Placuna placenta, or the windowpane oyster, these shells are increasingly being discussed in research on sustainable materials, coastal ecosystems, and alternative resource use.</p>.<p>What sets capiz shells apart is their unusual physics. Unlike the thick, opaque shells of most oysters, they are thin, flat, and naturally translucent. Their structure, made of layered calcium carbonate, allows light to pass through while diffusing it softly, creating a natural glazing effect. Long before industrial glass became widely available, this property made capiz shells an architectural solution across tropical regions.</p>.<p>This species lacks the iridescence of pearl oysters and the culinary dominance of edible varieties like Crassostrea. It is a niche as a “biomaterial species,” valued more for the physical properties of its shell than for food.</p>.Mumbai’s historic Sassoon Dock to be transformed into modern, eco-friendly fishing harbour.<p>This distinction has made it popular in export-driven handicraft industries and sustainable designs. Today, it is drawing attention in design circles exploring low-energy, nature-based materials. It is used in chandeliers, lampshades and other decorative items.</p>.<p>However, in India today, capiz oysters are not legally cultivated, and their use remains limited. In 2023, Maharashtra police seized 30 tonnes of capiz shells, supposedly harvested in quantities exceeding the allowed limit. Their harvesting and trade fall under broader marine and wildlife regulations, and their sale is banned under Schedule IV of the Wildlife Protection Act, 1972. </p>.<p>For the same reason, homes in Goa and other parts of India with century-old capiz shells on windowpanes find it difficult to replace them. With all limitations, the capiz shell remains both underutilised and insufficiently studied in the Indian context.</p>.<p>Recent scientific studies from the Philippines, where capiz shells are primarily found and used widely, have broadened the lens beyond aesthetics. Researchers examining Placuna placenta have highlighted its nutritional potential, noting that the edible portion—often discarded in shell-focused industries—is rich in protein and minerals.</p>.<p>Because these oysters inhabit estuaries and coastal shallows, they are vulnerable to the accumulation of heavy metals and other pollutants. Studies warn of declining populations due to overharvesting and habitat stress, raising questions about the long-term sustainability of the capiz shell trade.</p>
<p>This photograph shows a remnant of a bygone era, when the wealthy in <a href="https://www.deccanherald.com/india/goa">Goa</a> used shells to cover windows without blocking light. The material behind it—the capiz shell—is finding renewed relevance today, as a subject of scientific and environmental interest.</p>.<p>Derived from the marine bivalve Placuna placenta, or the windowpane oyster, these shells are increasingly being discussed in research on sustainable materials, coastal ecosystems, and alternative resource use.</p>.<p>What sets capiz shells apart is their unusual physics. Unlike the thick, opaque shells of most oysters, they are thin, flat, and naturally translucent. Their structure, made of layered calcium carbonate, allows light to pass through while diffusing it softly, creating a natural glazing effect. Long before industrial glass became widely available, this property made capiz shells an architectural solution across tropical regions.</p>.<p>This species lacks the iridescence of pearl oysters and the culinary dominance of edible varieties like Crassostrea. It is a niche as a “biomaterial species,” valued more for the physical properties of its shell than for food.</p>.Mumbai’s historic Sassoon Dock to be transformed into modern, eco-friendly fishing harbour.<p>This distinction has made it popular in export-driven handicraft industries and sustainable designs. Today, it is drawing attention in design circles exploring low-energy, nature-based materials. It is used in chandeliers, lampshades and other decorative items.</p>.<p>However, in India today, capiz oysters are not legally cultivated, and their use remains limited. In 2023, Maharashtra police seized 30 tonnes of capiz shells, supposedly harvested in quantities exceeding the allowed limit. Their harvesting and trade fall under broader marine and wildlife regulations, and their sale is banned under Schedule IV of the Wildlife Protection Act, 1972. </p>.<p>For the same reason, homes in Goa and other parts of India with century-old capiz shells on windowpanes find it difficult to replace them. With all limitations, the capiz shell remains both underutilised and insufficiently studied in the Indian context.</p>.<p>Recent scientific studies from the Philippines, where capiz shells are primarily found and used widely, have broadened the lens beyond aesthetics. Researchers examining Placuna placenta have highlighted its nutritional potential, noting that the edible portion—often discarded in shell-focused industries—is rich in protein and minerals.</p>.<p>Because these oysters inhabit estuaries and coastal shallows, they are vulnerable to the accumulation of heavy metals and other pollutants. Studies warn of declining populations due to overharvesting and habitat stress, raising questions about the long-term sustainability of the capiz shell trade.</p>