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 NOAA Helps American Samoa Tackle a Thorny Issue crown of thorns close-up with text that says 'reef predator'  Divers **remove crown-of-thorns starfish** from the islands’ **coral reefs** American  Samoa is tackling a thorny issue on its nearshore coral reefs. The issue  takes the form of crown-of-thorns starfish (COTS), prickly critters, known locally as alamea, that  voraciously consume the live stony corals that form the reefs’ limestone foundation. COTS can  grow 14 or more inches across and may have as many as 21 arms. Long, stiff spines  protruding from the animal’s arms and crown-like central disk (thus the name)  contain powerful venom. When a predator—or anyone unfortunate enough to step  on or otherwise touch a COTS—gets too close, the spines deliver a painful  sting and may also embed in the unwary intruder’s flesh. NOAA diver Kelly Gleason injects a crown-of-thorns starfish. Divers inject the central disk near an arm of each starfish with ox bile, a natural substance that kills the creature but does no harm to the reef. *(credit: Greg McFall, NOAA Dive Program)* | Download  **Too many** Starfish Around 2012, the COTS population began to explode. Similar outbreaks in the past destroyed essential  fish habitat and caused negative long-term effects on local fisheries. Land-based pollution and  the subsequent runoff of nutrients like nitrogen and phosphorus are believed to cause most COTS outbreaks. Excess  nutrients change the ecology of the reef, giving the starfish “a leg up” during  the larval stage. Another theory links the  outbreak to the 2009 tsunami, which may have dislodged sediments and stirred  up nutrients from the ocean floor. The timing of the outbreak and the fact that  today’s mature COTS would have been in the larval stage in 2009 seem to support  this possibility. In this image, the middle section (white) part of the coral has been destroyed by a crown of thorns starfish. Blue-green algae is seen growing over dead portions of the coral on the right. The left side of the coral still contains living tissue. *(credit: Greg McFall, NOAA Dive Program)* | Download  COTS **Removal** Effort NOAA’s Coral  Reef Conservation Program (CRCP) recently supported the removal of nearly 200 COTS from nearshore reefs  around the islands of Tu-tuila and Aunu’u in partnership with the National  Marine Sanctuary of American Samoa,  the American Samoa Coral Reef Advisory Group, and others. It was the second year  of an effort to identify areas with the highest densities of COTS and employ a  team of NOAA divers to extract them. Divers inject the central disk near an arm of each starfish  with ox bile, a natural substance that kills the creature but does no harm to  the reef. To do so, each diver uses an ox-bile injector—an 18-inch-long metal tube that houses a syringe, a needle, and enough ox bile to  inject up to 100 COTS. A close-up of a crown-of-thorns injection. To date, CRCP has supported partner  efforts to remove more than 7,000 COTS around American Samoa. *(credit: Greg McFall, NOAA Dive Program)* | Download  **Future** Plans To date, CRCP has supported partner  efforts to remove more than 7,000 COTS around American Samoa. The removal  effort may be working, since the number of COTS eliminated so far this year was  far fewer than the 1,440 removed just last year. The smaller number found this  year still indicates outbreak levels, however. Ongoing monitoring and removal efforts  will be necessary to keep COTS numbers low and prevent a rebound in the  outbreak. Additionally, a long-term plan to address the threat is being  developed with relevant agencies and partners. A Samoan saying  is that “The best thing for an alamea sting is the alamea itself,” which refers  to using the COTS’s own venom to treat its sting—a sound concept that modern  medicine calls immunotherapy. NOAA’s efforts to hold the COTS population at bay  should go far to reduce the creature’s “stinging” effects on the islands’ fragile  coral reefs.  Parting **Words** NOAA’s Coral Reef Conservation Program supports effective management and sound science to preserve, sustain, and restore valuable coral reef ecosystems for future generations. Other partners involved in the American Samoa COTS removal program include the American Samoa Department of Marine and Wildlife Resources, Papahānaumokuākea Marine National Monument, NOAA Dive Center, and Grey’s Reef National Marine Sanctuary.
 **Did you know?** A devastating COTS outbreak in the late 1970s killed *80 percent of the coral on American Samoa’s reefs*. The negative environmental and economic consequences propelled the 1986 designation of the National Marine Sanctuary of American Samoa, which originally protected .25 square miles of coral reefs in Fagatele Bay. Once the smallest of the 13 national marine sanctuaries, this sanctuary is now the largest. In 2012, NOAA expanded the sanctuary to its current size, which covers 13,581 square miles of nearshore coral reefs and offshore waters across the Samoan Archipelago.
   More **Information**  NOAA Coral Reef Conservation Program
          National Marine Sanctuary of American Samoa
          NOAA National Marine Sanctuaries
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