Coral Rehabilitation

Coral rehabilitation is one of the viable management tools to restore the services of degraded reef areas due to climatic and non-climatic In India, coral rehabilitation was first initiated in Tuticorin coast of Gulf of Mannar in 2002 by SDMRI with the support from Ministry of Environment and Forests and Coral reef Degradation in Indian Ocean (CORDIO). The researchers from SDMRI successfully standardized and field tested the low cost and low tech transplantation technique using artificial substrates like cement frames and multipurpose fish houses with native coral species (Acropora nobilis, A. formosa, A. intermedia, A. cytherea, A. valida, A. humilis, A. corymbosa, Montipora divaricata, M. digitata, M. foliosa, Pocillopora damicornis, Turbinaria mesenterina, T. peltata, T. crater, Favia pallida, Favites abditta and Porites solida).

The selection of sites, identification of healthy native coral colonies for fragments near the rehabilitation sites, precision in fragmentation, reduction of time from fragmentation to fixation on substrates, fragment fixing position and regular monitoring are important for the success of coral rehabilitation. Matured gametes were observed in some transplanted corals of A. cytherea and A. formosa after one year.

Coral rehabilitation is successful only if native healthy coral colonies are available. Different species of native corals need to be rehabiliated to facilitate heterogenity in the site. Coral rehabilitation using fragments from other environmentally different location will not be successful.

In Tuticorin coast, over 1 km2 degraded reef area has been rehabilitated and the overall survival was over 80%. The coral recruit density increased from 0.53 to 2.55 per m2; and fish abundance increased from 34 to 65 per 100 m2 in 5 years.

Tamil Nadu Forest Department funded rehabilitation of 2 km2 degraded reef area in 4 islands and GOMBRT funded rehabilitation of 1 km2 degraded reef area in 2 Islands in Gulf of Mannar, following the transplantation technique.

SDMRI recently (2012-2013) completed rehabilitation of 1 km2 degraded reef area near Vaan Island in Tuticorin coast with the support from GIZ under the supervision of Department of Environment, Government of Tamil Nadu.

Steps have to be taken not only to rehabilitate the other degraded reef area in a phased manner in order to restore the live coral cover and its ecosystem services, but also to monitor the success for better management.