The Rockwater Coral Gardens:

We routinely inspect and maintain the reef from all predators such as the Crown of Thorns, collect rubbish dumped by ships, and washed-up cyclone or man-made debris.

We ask for your cooperation preserving this beautiful reef for the next generations by adhering to two simple rules:

1: Do not walk on living coral, anywhere, anytime.
2: Remove anything from the reef, it does not belong anywhere else.
Please be aware non-compliance to these two basic rules may result in being banned from enjoying our reef.
Further breaches may result in being asked to leave the resort without any refund for unused room nights.

Tip: The less sound you make when snorkelling; the more turtles, fish, and lobsters you will see!

There are three areas of coral to be explored:

The Shoreline coral gardens (referred to as the Inner Reef).
These start at 5 to 10 meters out from our shoreline extending up to the drop-off.
This magnificent low lying coral garden is very fragile and a rare ecosystem to find on Tanna as indigenous and tourism operators over usage has had decimated their reefs.
Within this "lace" coral belt lives a myriad of small marine life such as shells, miniature fish, and crustaceans. This reef is exposed at low tide and only accessible by snorkelling at high tide.

The Drop-off coral wall (referred to as a Reef Crest).
These are the tougher corals used to the constant sea pounding.
The Outer Reef where scuba diving takes place and the occasional "bommie" can be found."

 

 Picture and information below - source: Wikepedia

Coral Reefs are Rain Forests of the Ocean

Coral reefs are living animal colonies that provide nesting places for fish and other under water creatures. They are important elements of our oceans’ eco systems and if destroyed, the fish will look for housing elsewhere and reduce food and tourism for the locals.

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. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps belong to a group of animals known as Cnidaria, which also includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons which support and protect the coral polyps. Most reefs grow best in warm, shallow, clear, sunny and agitated water.

Often called "rainforests of the sea", shallow coral reefs form some of the most diverse ecosystems on Earth. They occupy less than 0.1% of the world's ocean surface, yet they provide a home for at least 25% of all marine species. Paradoxically, coral reefs flourish even though they are surrounded by ocean waters that provide few nutrients. They are most commonly found at shallow depths in tropical waters, but deep water and cold water corals also exist on smaller scales in other areas.

Coral reefs deliver ecosystem services to tourism, fisheries and shoreline protection. The annual global economic value of coral reefs is estimated between US$30–375 billion. However, coral reefs are fragile ecosystems, partly because they are very sensitive to water temperature. In Vanuatu they are under threat from climate change, oceanic acidification, for aquarium fish, sunscreen use,^[8] overuse of reef resources from uncaring resorts and harmful land-use practices, including urban andagricultural runoff and water pollution, which can harm reefs by encouraging excess algal growth

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. As communities established themselves on the shelves, the reefs grew upwards, pacing rising sea levels. Reefs that rose too slowly could become drowned reefs. They are covered by so much water that there was insufficient light.^[12] Coral reefs are found in the deep sea away from continental shelves, around oceanic islands and as atolls. 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.

In 1842 in his first monograph, The Structure and Distribution of Coral Reefs, Charles Darwin set out his theory of the formation of atoll reefs, an idea he conceived during the voyage of the Beagle. He theorized uplift and subsidence of the Earth'scrust under the oceans formed the atolls. Darwin’s theory sets out a sequence of three stages in atoll formation. It starts with a fringing reef forming around an extinct volcanic island as the island and ocean floor subsides. As the subsidence continues, the fringing reef becomes a barrier reef, and ultimately an atoll reef.

 

 

 

Darwin’s theory starts with a volcanic island which becomes extinct

 

 

As the island and ocean floor subside, coral growth builds a fringing reef, often including a shallow lagoon between the land and the main reef.

 

 

As the subsidence continues, the fringing reef becomes a larger barrier reef further from the shore with a bigger and deeper lagoon inside.

 

 

Ultimately, the island sinks below the sea, and the barrier reef becomes an atoll enclosing an open lagoon.

Darwin predicted that underneath each lagoon would be a bed rock base, the remains of the original volcano. Subsequent drilling proved this correct. Darwin's theory followed from his understanding that coral polyps thrive in the clean seas of the tropics where the water is agitated, but can only live within a limited depth range, starting just below low tide. Where the level of the underlying earth allows, the corals grow around the coast to form what he called fringing reefs, and can eventually grow out from the shore to become a barrier reef.

Where the bottom is rising, fringing reefs can grow around the coast, but coral raised above sea level dies and becomes white limestone. 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. A barrier reef can encircle an island, and once the island sinks below sea level a roughly circular atoll of growing coral continues to keep up with the sea level, forming a central lagoon. Barrier reefs and atolls do not usually form complete circles, but are broken in places by storms. Like sea level rise, a rapidly subsiding bottom can overwhelm coral growth, killing the coral polyps and the reef, due to what is called coral drowning. Corals that rely on zooxanthellae can drown when the water becomes too deep for their symbionts to adequately photosynthesize, due to decreased light exposure.

Healthy tropical coral reefs grow horizontally from 1 to 3 cm (0.39 to 1.18 in) per year, and grow vertically anywhere from 1 to 25 cm (0.39 to 9.84 in) per year; however, they grow only at depths shallower than 150 m (490 ft) because of their need for sunlight, and cannot grow above sea level.