Coral reef a protective area, or it may lie between the reef and the shore, and in this case is a flat, rocky area. Fish tend to prefer it when it is present. The reef lagoon is an entirely enclosed region, which creates an area less affected by wave action and often contains small reef patches. However, the "topography of coral reefs is constantly changing. Each reef is made up of irregular patches of algae, sessile invertebrates, and bare rock and sand. The size, shape and relative abundance of these patches changes from year to year in response to the various factors
Coral Sea Islands areas for birds and turtles but contain negligible natural resources. They comprise less than of land. There is no port or harbour, only offshore anchorage. Most of the atolls fall into two groups, while Mellish Reef to the east, and Middleton Reef and Elizabeth Reef to the south are grouped separately: The atolls of the Northwestern Group, except Osprey Reef and Shark Reef in the north, and Marion Reef in the south, are located on the Coral Sea Plateau (Queensland Plateau), a contiguous area of depths less than 1000 m. The Nature Reserves were created to protect wildlife in the