We lived and taught on the island of Guam from 1970 to 1974. That was where we encountered this curious animal, the Crown of Thorns starfish, Acanthaster planci, who destroys living coral. He doesn’t mean anything by it. That’s just the way he gets his food, by dining on the small animals who live inside their coral caves. The once vibrant colors of the reef become the fetching grey of concrete. The reef soon becomes covered with slimy green algae. The algae don’t mean anything by being slimy and green, either. That’s just the way they are. The best you can say for the algae is that the dead coral is no longer grey.
With the coral reefs dead, the fish soon disappear, first the one who directly depend on coral for the sustenance, and then the other fish who consume the coral eaters.
But there is worse.
Guam is a part of the Marianas Islands chain, a group if islands built almost entirely of coral and protected from instant destruction by the coral reef. And the Pacific Ocean around the islands is very deep. How deep is very deep? Try seven miles, the depth of the Marianas Trench not too distant to the east.
For we who lived on Guam, the plague of coral eating starfish posted a problem. We had to take strenuous counteraction. Either that, or pray and practice our dog paddle.
Not everyone on the island saw the Crown of Thorns as a problem. One sailor on the Naval Station took the opposite view. One graffito found on a men’s room wall exhorted, “Go, Crown of Thorns!”
But most of the divers and snorkelers with whom we associated felt very differently about good old A. planci. Search and destroy parties were organized to locate, gather and dispose of the pest. But you had to be careful because any animal that could munch coral could do serious damage to the bod as well. If one of them nails you with a few spines, the result will be colorful scarred pits. The spines themselves can be up to two inches and extend downward from the up to 30 arms the animal may possess. Most Crown of Thorns starfish are around a foot in diameter, but they have found a few elsewhere measuring over 30 inches.
Some people tried to chop the animal up. But they were informed as they were happily chopping away that all they were doing was creating new starfish. Starfish have some great regenerative properties.
The next solution worked. Not a silver bullet or a stake through the heart, but burning alive. Hey, it worked for the Inquisition. Why not for us?
However, the sound and the smell of this splendid solution were yucky in the extreme. It was so unpleasant that few people wanted to do it. There was something so basically satisfying about chopping them and chopping them and chopping them.
Fortunately, the infestation ended by itself, although there have been other major invasions throughout the Indian Ocean and the South Pacific, most notably on Australia’s Great Barrier Reef currently. Guam’s plague doesn’t even merit a mention among those people studying and dealing with A. planci. Our Crown of Thorns invasion was just a minor episode in a long line of inconvenient cosmic events.
It was just one of those things, just one of those crazy things.