TAIPEI (Taiwan News) — A National Sun Yat-sen University study found that plastics can affect the crystal structure of coral skeletons, causing an "osteoporosis" that weakens the coral.
The study was published in the international journal “Environmental Chemistry Letters." It was conducted by Hsieh Shu-chen (謝淑貞), National Sun Yat-sen University's chemistry department chair, and Chen Chen-tung (陳鎮東), Academia Sinica's marine science department chair, per CNA.
The research found that soft corals such as star polyp (briareum violacea) when exposed to seawater containing 5 ppm polyethylene plastic particles experienced abnormal growth of the coral skeleton. Researchers said it made the coral susceptible to a type of "osteoporosis."
The star polyp’s skeleton is made of calcium carbonate secreted by coral polyps, forming tiny calcium carbonate spicules. These spicules are scattered throughout the coral's tissue, providing a supportive structure for the coral and a habitat for marine organisms.
The research team found that healthy star polyps contain two forms of calcium carbonate crystals: calcite and aragonite. As the concentration of polyethylene plastic particles increases, the structure of calcite is significantly weakened, while the aragonite crystals almost totally disappear and are replaced by unstable amorphous calcium carbonate.
The study found that plastic particles not only damage the structural integrity of coral skeletons, making them more susceptible to dissolution, but also change the concentration of calcium ions in seawater. Seawater analysis shows a significant increase in calcium ion concentrations, suggesting that coral skeletons are becoming more susceptible to dissolution.
The research shows that the damage plastics pose to corals is greater than previously known. As plastic waste increases, the marine environment will further deteriorate.
Hsieh expects more coral will be affected, especially those in polluted environments. She called for more measures to control plastic pollution.