bio-invasion:The exotic seaweed seen on Krusadai Island.
CHENNAI: Coral colonies in the Gulf of Mannar Biosphere Reserve are facing serious threat from an invasive seaweed, which is spreading rapidly, say marine researchers, who are worried about the phenomenon.

The bio-invasion by the sea weed, Kappaphycus alvarezii, was spread over only 10 square metres in 2008 in three islands