The soft coral was noticed in Wandoor jetty in the Mahatma Gandhi Marine National Park, Andaman, in June 2009.

Snowflake coral (Carijoa riisei), a shallow fast-growing soft coral, is posing a major threat to the coral reef colonies in the Gulf of Mannar, Gulf of Kutch and the Andaman and Nicobar Islands.

Director of the Zoological Survey of India (ZSI) K. Venkataraman told The Hindu that the invasion by this soft coral on the coral reef colonies was first reported in Kundol Island in Nicobar in May 2009.

The growth of the soft coral colonies was observed on the pilings of the 100 metre-long abandoned jetty at a depth of three metres to 20 metres. They were bright red in colour with an orange tinge on the edges. These organisms were attached to the pilings and had erect growth of up to 40 cm with several intermediate branches.

The soft coral was noticed in Wandoor jetty in the Mahatma Gandhi Marine National Park, Andaman, in June 2009. In October this year, the ZSI found the species in Peel Island of the Ritchie’s Archipelago in the Rani Jhansi Marine National Park. Observations indicated that four major coral reef zones in the country had been affected by the this soft coral, Dr. Venkataraman said.

The soft coral, which monopolised the food and space resources of the coral reef ecosystem, exhibited high fecundity and produced hundreds of eggs and appeared to reproduce continuously throughout the year, irrespective of the seasons, Dr. Venkataraman said.

Studies by the ZSI and other organisations revealed that dispersal of this soft coral was through the ballast water of ships. Translocation of organisms through ships is considered to be one of the important issues that threatened the naturally evolved biodiversity.

Dr. Venkataraman said, “With limited information available on marine bio-invasion in tropical countries, including India, there is an urgent need to study the occurrence and impacts of invasive species in coral reefs, which harbours 25 per cent of total marine biodiversity and contribute 10 per cent to fishery production.”