Progress report for
Coastal Habitat Rehabilitation in Gulf of Mannar, Tamil Nadu, India
Achievement at a glance
The rehabilitated coral sites in Koswari Island of Gulf of Mannar (2 acres) was continuously monitored to document survival, growth, recruitment density, associated fish assemblages, and macro faunal community from December 2016 to October 2018.The survival of the transplanted corals slightly decreased, with an average of 84.58% during the study period of 23 months. Turbinaria mesenterina had the highest survival rate of 93.65%, followed by Acropora cytherea with 87.25%, while the survival of other species were A. nobilis (86.25%), A. formosa (87.25%), A. nobilis (86.25%), Montipora digitata (77.21%), M. divaricata (72.28%) and M. foliosa (84.68%). Of the transplanted coral species, A. intermedia (28.51 cm) and A. cytherea (26.03 cm) exhibited highest coral growth by the end of the monitoring in October 2018. In coral recruitment density, the highest density was found for the genus Acropora with 0.39 followed by Favia with 0.29 No/module respectively.
In addition to monitoring, regular maintenance of rehabilitated site such as cleaning of algae, change of fragments disturbed by fishermen and removal of ghost nets, is also being carried out in order to have good coral growth
In Koswari Island, the live coral cover was 15.27% in 2005 and it gradually increased to 27.32% until 2015 which was again significantly reduced to 17.56% in 2016 due to coral bleaching and subsequent mortality. However, the successful coral rehabilitation has helped to increase the live coral cover to 20.07% during 2018.
The monitoring results of rehabilitated seagrass area (2 acres) will be updated shortly.