Reef Teach Great Barrier Reef learn about the Great Barrier Reef

	Crown of Thorns

	This animal eats coral and we have had three massive plagues through the Cairns section of the Great Barrier Reef since the 1960s. Each one of these resulted in colossal killing off of reef areas. It must be remembered that these Crown of Thorns plagues are definitely natural. That is, just like lung cancer is natural. Our societys activities have had as much effect on the Crown of Thorns plagues as we have had on lung cancer.