History and Prospects for the Sustainability and Circularity of the Windowpane Oyster Placuna placenta Fishery in the Philippines

The windowpane oyster Placuna placenta lives in brackish coastal waters and has long been economically important to the Philippines because of its durable and translucent shell, which is used as a glass substitute and material for making windowpanes and handicrafts. There has been considerable degradation of the P. placenta fishery over the past decades. Moreover, there are waste and under-exploited by-products, such as the meat, which though nutritious and edible, currently has a very low value; its use is confined to dishes consumed by families in the fishing community. Historically, there have been instances of excellent practice in terms of regulating the P. placenta fishery, while in recent times, there have been local initiatives to restore this and to develop high-value food products from the meat. These initiatives have, however, never been followed through at a provincial or national level. Research on other molluscs and marine organisms highlights that these contain high-value pharmaceutical products, an unexplored facet of P. placenta. This review compiles evidence to establish the groundwork for an essential and comprehensive multidisciplinary research programme centred around the P. placenta, which would ensure a high value for all parts of the oyster, including those currently discarded. By fostering a sustainable and circular economy within this fishery sector and its associated industry, its economic value would be amplified. This is particularly important for oyster harvesters in the Philippines, who often find themselves on the economic ladder’s lower rungs. By integrating the principles of a circular economy, this initiative would not only aim to uplift the economic prospects of these harvesters, but in doing so would drive the restoration of P. placenta to its former range.