page_title: Coral island
section_title: Ecosystem
hierarchical_section_title: Coral island / Ecosystem
caption_attribution_description: English: Coral reef ecosystem at Palmyra Atoll National Wildlife Refuge, Palmyra Atoll, central equatorial Pacific Ocean.
context_page_description: A coral island is a type of island formed from coral detritus and associated organic material. They occur in tropical and sub-tropical areas, typically as part of coral reefs which have grown to cover a far larger area under the sea.
context_section_description: Coral reefs are some of the oldest ecosystems on the planet. Over geological time forming massive reefs made of limestone. The reef environment supports more plant and animal species than any other habitat. Coral reefs are vital for life for multiple aspects some of which include structure, ecology, and nutrient cycles which all support biodiversity in the reefs.
  The reefs build massive calcareous skeletons that serve as homes for animals from fish hiding inside the crooks and crannies of the reef and barnacles attaching themselves directly to the coral’s structure.  The reef’s structure also helps with plants that need the sun to photosynthesize; by lifting the plants to the ocean’s surface where the sunlight can penetrate the water. The structure of the reef also creates a calm zone in the ocean providing a great place for fish and plant species to thrive.
  Over geological time the reefs reach the surface and can become a coral island, where it begins a whole new ecosystem for land-based creatures.
caption: Healthy reef system
exif: {"Image SubfileType": "Full-resolution Image", "Image ImageWidth": "5625", "Image ImageLength": "3744", "Image BitsPerSample": "[8, 8, 8]", "Image Compression": "LZW", "Image PhotometricInterpretation": "2", "Image StripOffsets": "[]", "Image SamplesPerPixel": "3", "Image RowsPerStrip": "1", "Image StripByteCounts": "[]", "Image XResolution": "300", "Image YResolution": "300", "Image PlanarConfiguration": "1", "Image ResolutionUnit": "Pixels/Inch", "Image Predictor": "Horizontal differencing", "Image Tag 0x8649": "[]"}