Experimental re-introduction of Acropora corals from Lakshadweep Islands to Mithapur coral reef, Gulf of Kutch, Gujarat, India

Summary

Branching Acropora corals, historically present but now apparently locally extinct in India's Gulf of Kutch, where only slower-growing boulder corals remain amid extreme environmental variation and reef-destructive fishing, were the subject of India's first long-distance coral translocation, moving Acropora humilis fragments 1,300 km from an in-situ nursery in the Lakshadweep Islands to the Mithapur reef under a public-private partnership between the Wildlife Trust of India, Gujarat Forest Department, Tata Chemicals Limited, and the Lakshadweep Forest Department. In March 2012, 22 sixty-day-old coral fragments were transported by ship, rail and road over a four-day journey; four died from transport stress, and the surviving 18 fragments (13 healthy, 5 stressed) were transplanted at two Gulf of Kutch sites. Post-transplantation monitoring over six months found all five stressed fragments died within days, while healthy fragments survived until September 2012 before bleaching and dying, coinciding with a broader bleaching event that also killed many of the region's more resilient native boulder corals following the southwest monsoon; competition from macroalgae and colonization by hydrozoans and ascidians further damaged the transplanted coral tissue. The experiment nonetheless demonstrated that Acropora humilis fragments can survive long-distance transport and persist for several months in Gulf of Kutch waters, suggesting the habitat is not entirely unsuitable given more favorable conditions or, as later research recommended, prior small-scale piloting. The project rates itself a failure, attributing the outcome to water turbidity from suspended sediment and strong currents during the southwest monsoon season.