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Plenty more fishes n dating agencies

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If the land subsides slowly, the fringing reefs keep pace by growing upwards on a base of older, dead coral, forming a barrier reef enclosing a lagoon between the reef and the land.

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As the sea level rise continued, water topped most of the continental islands.The corals could then overgrow the hills, forming the present cays and reefs.Sea level on the Great Barrier Reef has not changed significantly in the last 6,000 years, Although the Great Barrier Reef formed along a continental shelf, and not around a volcanic island, Darwin's principles apply.The vast majority of these islands are volcanic in origin.The few exceptions have tectonic origins where plate movements have lifted the deep ocean floor on the surface.As communities established themselves on the shelves, the reefs grew upwards, pacing rising sea levels.

Reefs that rose too slowly could become drowned reefs.

Coral reefs are diverse underwater ecosystems held together by calcium carbonate structures secreted by corals.

Coral reefs are built by colonies of tiny animals found in marine water that contain few nutrients.

They are under threat from climate change, oceanic acidification, blast fishing, cyanide fishing for aquarium fish, sunscreen use, Most of the coral reefs we can see today were formed after the last glacial period when melting ice caused the sea level to rise and flood the continental shelves.

This means that most modern coral reefs are less than 10,000 years old.

Unlike sea anemones, corals secrete hard carbonate exoskeletons which support and protect the coral polyps.