Chinese scientists published new research Monday on the marine conditions near Ren'ai Jiao, an island reef in the South China Sea. A drastic decline in the coverage area of hermatypic corals, the most important organism that constitutes the coral reef ecosystem, was detected. Experts have ruled out factors such as rising sea temperatures and tropical cyclones, saying their latest investigation indicates that the grounded Filipino ship there has become a major source of pollution that threatens the coral reef ecosystem in the area.