Research Reveals Plastic Fusion with Coral Reefs

Marine plastic pollution is widespread, with plastic waste found in various marine ecosystems, including beaches and coral reefs. It is estimated that several million metric tons of plastic are present on the seafloor. Scientists have documented marine animals entangled in or consuming plastic debris for over 50 years, coining the term "Plastocene" to describe the geological epoch from the 1950s onward. Recent research has identified a new form of pollution: plastic fusing with corals, termed "plasticoral." This discovery occurred during a survey of the Ryukyu Islands in southern Japan, where researchers observed small, brightly colored spots in white coral gravel. Samples collected from three beaches on Okinawa were analyzed in the lab, revealing polymers from common household plastics. Micro-CT scans indicated that these polymers had melted into the microscopic pores of coral fragments, making them inseparable. While plastic has previously been found associated with nonliving organisms, this study marks the first instance of plastic fused with corals. The "plasticoral" was discovered at a bonfire site on Chushu Beach, likely formed from discarded plastic waste. Although coral rubble is no longer a living organism, it plays a vital role in coral reef ecosystems by providing a foundation for new corals and shelter for marine organisms. The impact of plasticorals on living corals is still unclear, but past research indicates that chemicals from plastics can inhibit coral reproduction, and plastic fragments may carry pathogens to corals. The exact mechanism of fusion between plastic and corals remains uncertain. While ocean temperatures are rising, they are not yet sufficient to melt plastic. Ultraviolet radiation may contribute, but researchers suspect beach bonfires are the primary cause. Further investigation is needed to confirm these findings, highlighting the pervasive nature of plastic pollution even in seemingly pristine areas.