Pacific Coral Reef | Nature of America

Coral reefs and their surrounding waters are complex ecosystems supporting thousands of different life-forms. But like the biologically rich rain forests of the tropics, they are also fragile realms, sensitive to temperature changes and highly vulnerable to human activities that exploit their resources.

Reefs can stretch for miles in the clear, shallow waters of the tropics and subtropics. Built up primarily by coral polyps, tiny organisms that secrete calcium carbonate, these massive structures protect the shores of nearby landmasses from wave-induced erosion while providing food and shelter for countless creatures.

The stamp pane depicts a coral reef near Guam, a United States territory in the western Pacific Ocean. In this scene, a large humphead wrasse eyes its neighbors as a blacktip shark prowls in the distance. Meanwhile, a spectacular lionfish-one of many reef dwellers characterized by elaborate patterns and bright colors-forages among the coral for shrimps, crabs, and small fish.