Are Lakshadweep Corals Heading Toward COT Outbreak

Abstract

Crown-of-Thorns (COT) predation off Kavaratti and Agatti islands in the Lakshadweep reef system has increased sporadically in recent years and appears to be approaching outbreak status, as indicated by a study of the starfish’s spatial progression along 16 transects off each island between 2010 and 2012. Infestation along one transect rose from 3 COTs in 2010 to 18 COTs in 2012. A threat susceptibility level for corals calculated as stressors/total live corals present along each transect averaged 38.9% to 52.5% in 2011 and 43.5 to 52.6% in 2012. Over much of the study period, COT exhibited selective feeding on branching corals but then shifted to Pavona sp. during 2012. High periodicity in COT prevalence was also observed, with a higher population during March–May (pre monsoon) and August–September (post monsoon), months when the corals were under severe environmental stress.