Crown of Thorns Starfish Outbreaks in American Samoa
Past Events
Crown of Thorns Starfish (COTS) (Acanthaster planci) also known as ‘alamea’ in Samoan are naturally occurring corallivores in the Pacific region, but can become a nuisance in high numbers. A single COTS can consume up to 100 sq. ft. of living coral in a year, with a preference for fast-growing scleractinians. COTS have the ability to push their stomach out through their mouth, covering a coral and using digestive enzymes to break down the coral animal. After eating the coral tissue they move on, leaving behind the white coral skeleton. COTS outbreaks are increasingly likely due to overfishing of their natural predators, leaving their populations unchecked.
C/O Wendy Cover 2014 (NMSAS)
COTS Outbreak in Tutuila 2011-2014
COTS populations began to expand in mid-2012, quickly growing to outbreak levels. Removal efforts began in the hope of reducing numbers before the breeding season and preventing secondary populations from forming. The National Marine Sanctuary of American Samoa (NMSAS), National Park of American Samoa (NPAS) and the Department of Marine and Wildlife Resources (DMWR) have been collaborating to combat this threat and save corals. The most efficient removal method is to inject COTS with sodium bisulphate, a poison that kills the starfish but does not harm the reef. Injections are fast and reduce the risk of divers being stung by the COTS. To date, combined efforts have removed approximately 5,000 COTS, but the densest populations remain.
COTS Outbreak in Tutuila
1978-1979
In the late 1970s, millions of crown-of-thorns starfish, a coral-eating animal, ate their way through Tutuila's reefs in American Samoa. More than 90 percent of all the living corals were destroyed. At the time, Fagatele Bay was not a National Marine Sanctuary, but this disaster propelled the decision for the site's designation.
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