Two warring tribes invade their island; the boys intervene and manage to stop the atrocities. Ralph is captured by pirates before returning to his island, and Jack and Peterkin, in a happy, and extraordinarily fortunate, twist of fate. The Coral Island is directly referenced by Golding in Lord of the Flies.

Beaches develop around the shoal, and wind may heap up the lighter, finer material into dunes. Rainwater can now reach all this material, which, being almost entirely of calcium carbonate, is readily dissolved by it, and the dissolved lime is redeposited around the loose material, cementing it together.

The famous white-sand beaches of Hawaii, for example, actually come from the poop of parrotfish. The fish bite and scrape algae off of rocks and dead corals with their parrot-like beaks, grind up the inedible calcium-carbonate reef material (made mostly of coral skeletons) in their guts, and then excrete it as sand.

Coral reefs begin to form when free-swimming coral larvae attach to submerged rocks or other hard surfaces along the edges of islands or continents. If a fringing reef forms around a volcanic island that sinks completely below sea level while the coral continues to grow upward, an atoll forms. …

To keep yourself safe, people should keep general handling of corals to a minimum. Certain types of coral release the toxin into the air as a defence mechanism when they are under attack, and one gram of palytoxin can kill 80 people.

Coral reefs help to protect coastal communities from storm surges and erosion from waves, both of which are likely to increase in the face of sea-level rise. Coral reefs provide millions of jobs to local people through tourism, fishing, and recreational activities.

Increased ocean temperatures and changing ocean chemistry are the greatest global threats to coral reef ecosystems. These threats are caused by warmer atmospheric temperatures and increasing levels of carbon dioxide in seawater.