These activities are aimed at eliminating crown-of-thorns starfish and muricid gastropods for the prompt regeneration of coral reefs that have decreased due to the whitening of coral reefs and abnormal increase in crown-of-thorns starfish as a result of increases in the water temperature. While up until now the foreign invasion of coral reefs by crown-of-thorns starfish has been responded to with grinding using a hammer underwater, the aim of these activities is to promote the elimination of crown-of-thorns starfish and muricid gastropods and the regeneration of coral by switching to a method in which crown-of-thorns starfish are injected with acid using a syringe in order to avoid the damage that is caused currently.