reef


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reef:

see coral reefcoral reefs,
limestone formations produced by living organisms, found in shallow, tropical marine waters. In most reefs, the predominant organisms are stony corals, colonial cnidarians that secrete an exoskeleton of calcium carbonate (limestone).
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Reef

 

a sharp underwater or above-water elevation in the sea floor in shallow water that hampers navigation. Reefs are formed either by the erosion of the bottom and coasts of the sea or by colonies of coral.


Reef

 

a device for reducing sail area during a strong wind. The reef is usually a series of bands threaded through the sail, by means of which the sail is folded up when the boom or yard is taken up—that is, the sail is reefed, or taken in. Sails may have from one to four reefs.

reef

[rēf]
(geology)
A ridge- or moundlike layered sedimentary rock structure built almost exclusively by organisms.
An offshore chain or range of rock or sand at or near the surface of the water.
(mining engineering)
A major ore trend or ore body.

reef

1
1. a ridge of rock, sand, coral, etc., the top of which lies close to the surface of the sea
2. a ridge- or mound-like structure built by sedentary calcareous organisms (esp corals) and consisting mainly of their remains

reef

2 Nautical
the part gathered in when sail area is reduced, as in a high wind
References in periodicals archive ?
A single individual starfish can wipe out large areas of a reef.
has built a large artificial island on Mischief Reef, a low-tide elevation located in the exclusive economic zone of the Philippines;
They found that the the northern third of the Great Barrier Reef lost the highest amount of corals that year, while the central region suffered the most during another mass bleaching event in 2017.
"Reef Check was originally established in the US in 1996, and it is basically a voluntary conservation organisation that is dedicated to saving coral reefs globally.
"I've been to Australia before, but I've never been to the Great Barrier Reef. I've always wanted to go and it's been very high on my to-do list since watching Jacques Cousteau and then David Attenborough while growing up."
It was officially presented on December, 7, 2017 in Nairobi, during the 32nd General Assembly of the International Coral Reef Initiative.
At the end of the Blue Planet II reef episode, thousands of groupers gathered at the drop-off on a pristine and remote reef in French Polynesia, risking gatherings of hundreds of sharks to swim out into the tidal stream to spawn.
These polyps stay in one place, forming the structure of the reef and giving it shape.
The system allows Reef Innovations to build the reef balls by hand in remote areas.
Aragonite levels drop by about 50 percent around individual reefs compared with levels in the open ocean, the analysis suggests.
During preliminary field checking in the summer of 2010, unique reef signatures were developed for the three reef types: natural, dead, and restored (Fig.
Based on the condition of the Reef and events over the last five years, the report has downgraded the long-term outlook for the Reefs ecosystem from poor to very poor.