Abstract Summary
Gulf of Mannar is one of the four major coral reef areas in India. Out of an area of 110 km2, 32 km2 has been degraded due mainly to mining and destructive fishing practices. Low-tech and low-cost transplantation techniques using artificial substrates like concrete frames and fish houses were standardized during 2002-2005, and scaling up started in 2008. During 2002-2018, restoration was successfully done in 18 acres covering 7 islands. Survival rates of the transplants differed from Island to Island ranging between 67.28 and 81.6%. Fast growing genus Acropora showed higher growth at 15.96 cm/year, while in massive coral genera like Porites and Favia, higher growth was at 2 cm/year. Recently, climate change caused coral bleaching, and mortality is a major concern. The bleaching events in 2010 and 2016 killed 9.7% and 16.2% corals respectively. However in Gulf of Mannar there are species which are resistant to bleaching. Coral transplants in Koswari Island in southern Gulf of Mannar particularly showed the highest resistance to bleaching, for mortality was only 10.02%, while the bleaching intensity in Shingle Island in northern side was severe among the transplants and mortality was 78.78%. Restoration involving resistant and resilient coral species helps to save corals from the impacts of climate change. The selection of sites, identification of healthy native transplants, precision in fragmentation and fixing on substrates, and regular monitoring and maintenance are important for the success of coral restoration.
