A "plant killer" is spreading fast on the Neilingting Island in the sea across Shenzhen. Osmund Camomile are growing like huge nets one after another, covering all sorts of tropical plants and stuffing them to death. Osmund Camomile is originated in South America. They invaded southeastern coast of China in 1980's. They not only grow fast but also spread very far.

The scientists named the incidents like this as "biological pollution", meaning that foreign life-forms invade and destroy the original ecological system...

At present such foreign intruders are found in many lakes, rivers, large parts of offshore areas and islands. They are spreading into the continents, and have caused pollution.

Among them are...