Play Video
1
Reef - Place Your Hands
Reef - Place Your Hands
::2011/09/12::
Play Video
2
reef *new album* Lucky #5
reef *new album* Lucky #5
::2013/01/23::
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3
Reef Life of the Andaman (full marine biology documentary)
Reef Life of the Andaman (full marine biology documentary)
::2012/11/01::
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4
Reef - Naked
Reef - Naked
::2011/09/12::
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5
BBC Great Barrier Reef II 2012 HD الحيوانات بالريف الافضل وثائقي HD
BBC Great Barrier Reef II 2012 HD الحيوانات بالريف الافضل وثائقي HD
::2013/08/04::
Play Video
6
Adventure coral reef under the sea of Egypt
Adventure coral reef under the sea of Egypt
::2014/01/26::
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7
Compassing // a film by cyrus sutton x reef // free download at Reef.com
Compassing // a film by cyrus sutton x reef // free download at Reef.com
::2013/09/03::
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8
Chica Reef 2013
Chica Reef 2013
::2013/04/21::
Play Video
9
Great Barrier Reef Documentary
Great Barrier Reef Documentary
::2014/02/01::
Play Video
10
Building The Ultimate Reef Tank!!
Building The Ultimate Reef Tank!!
::2014/04/05::
Play Video
11
The 2011 Miss Reef Calendar
The 2011 Miss Reef Calendar
::2010/09/30::
Play Video
12
Colas Miss Reef Argentina
Colas Miss Reef Argentina
::2014/01/08::
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13
Great Barrier Reef  Nature
Great Barrier Reef Nature's Miracles Nature Documentary
::2013/11/28::
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14
De Passage
De Passage
::2014/06/14::
Play Video
15
Coral Reef Adventure 1-4 HD 720p
Coral Reef Adventure 1-4 HD 720p
::2011/06/15::
Play Video
16
2012 Miss Reef Calendar
2012 Miss Reef Calendar
::2011/11/22::
Play Video
17
The Reef  (The Heart Pounding Ending) HQ
The Reef (The Heart Pounding Ending) HQ
::2014/06/21::
Play Video
18
REEF - The Path of the Modern Gypsy
REEF - The Path of the Modern Gypsy
::2011/05/28::
Play Video
19
Largest Private Reef Aquarium
Largest Private Reef Aquarium
::2014/02/25::
Play Video
20
Squiddy Sundays - The Reef - I Believe I Can Fly
Squiddy Sundays - The Reef - I Believe I Can Fly
::2014/09/07::
Play Video
21
The Reef : Welcome to the server! - Ep 1
The Reef : Welcome to the server! - Ep 1
::2014/05/22::
Play Video
22
Matt
Matt's Reef Tank | Episode 1 | Tank Construction
::2014/04/27::
Play Video
23
Spearfishing the Great Barrier Reef
Spearfishing the Great Barrier Reef
::2012/07/02::
Play Video
24
Angry Birds Epic Star Reef Castle Walkthrough
Angry Birds Epic Star Reef Castle Walkthrough
::2014/03/22::
Play Video
25
ANGRY BIRDS Epic Android Walkthrough - Part 15 - Star Reef Castle
ANGRY BIRDS Epic Android Walkthrough - Part 15 - Star Reef Castle
::2014/06/22::
Play Video
26
Exploring Oceans: Great Barrier Reef
Exploring Oceans: Great Barrier Reef
::2009/03/30::
Play Video
27
Diving the Ribbon Reefs on Australia
Diving the Ribbon Reefs on Australia's Great Barrier Reef
::2011/08/01::
Play Video
28
Reef  - Set the Record Straight
Reef - Set the Record Straight
::2009/12/27::
Play Video
29
Reef The Lost Cauze - Moonshine prod. by Haj of Dumhi
Reef The Lost Cauze - Moonshine prod. by Haj of Dumhi
::2013/05/13::
Play Video
30
Large Reef Tank System
Large Reef Tank System
::2013/03/05::
Play Video
31
Destiny: The Reef Astroid Belt, Awoken FIrst cutscene, Awoken Queen Intro
Destiny: The Reef Astroid Belt, Awoken FIrst cutscene, Awoken Queen Intro
::2014/09/09::
Play Video
32
The Reef (2010)
The Reef (2010)
::2014/04/10::
Play Video
33
Bogan Loves the Great Barrier Reef
Bogan Loves the Great Barrier Reef
::2014/08/20::
Play Video
34
Nature
Nature's wonders: Coral reefs in HD
::2010/05/21::
Play Video
35
The Ultimate Reef Tank Lighting - AmericanReef Saltwater Tank ReefKeeping Video
The Ultimate Reef Tank Lighting - AmericanReef Saltwater Tank ReefKeeping Video
::2014/01/06::
Play Video
36
GoPro HD Scuba diving Great Barrier Reef
GoPro HD Scuba diving Great Barrier Reef
::2013/08/15::
Play Video
37
Dormero Rotes Ross Reef Aquarium June 2013
Dormero Rotes Ross Reef Aquarium June 2013
::2013/06/07::
Play Video
38
Reef The Lost Cauze  - "I
Reef The Lost Cauze - "I'm On My Phone" (Produced by Emynd)
::2014/02/27::
Play Video
39
Minecraft PC - Sky Wars/Bow Battle - The-Reef.eu
Minecraft PC - Sky Wars/Bow Battle - The-Reef.eu
::2014/05/18::
Play Video
40
Minecraft PC - The-Reef.EU - Cloudy Combat
Minecraft PC - The-Reef.EU - Cloudy Combat
::2014/05/11::
Play Video
41
Great Barrier Reef Dive & Snorkel - Port Douglas Australia
Great Barrier Reef Dive & Snorkel - Port Douglas Australia
::2014/03/29::
Play Video
42
Octonauts and The Great Ghost Reef | Best Kids Cartoons ✔
Octonauts and The Great Ghost Reef | Best Kids Cartoons ✔
::2014/02/18::
Play Video
43
Miss Reef Bikini Contest, Winter 2011 (HD)
Miss Reef Bikini Contest, Winter 2011 (HD)
::2011/09/11::
Play Video
44
How To: Dosing Two Part in Your Reef Tank
How To: Dosing Two Part in Your Reef Tank
::2014/01/10::
Play Video
45
The Reef (2010) - Official Trailer
The Reef (2010) - Official Trailer
::2011/01/10::
Play Video
46
Shallow Reef Suring | HD
Shallow Reef Suring | HD
::2013/01/15::
Play Video
47
Sonic & Knuckles Music: Lava Reef Zone Act 1 [extended]
Sonic & Knuckles Music: Lava Reef Zone Act 1 [extended]
::2008/12/15::
Play Video
48
Spearfishing the Swains Reefs- Southern Great Barrier Reef 2014
Spearfishing the Swains Reefs- Southern Great Barrier Reef 2014
::2014/04/06::
Play Video
49
Wild Kratts Rocket Jaw Rescuer of The Reef
Wild Kratts Rocket Jaw Rescuer of The Reef
::2014/07/22::
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50
Reef Roids Plankton Coral Feeding
Reef Roids Plankton Coral Feeding
::2013/10/29::
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RESULTS [51 .. 101]
From Wikipedia, the free encyclopedia
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For other uses, see Reef (disambiguation).
Pamalican island with surrounding reef, Sulu Sea, Philippines.
A reef surrounding an islet.

A reef is a rock, sandbar, or other feature lying beneath the surface of the water (80 meters or less beneath low water).

Many reefs result from abiotic processes—deposition of sand, wave erosion planing down rock outcrops, and other natural processes—but the best-known reefs are the coral reefs of tropical waters developed through biotic processes dominated by corals and calcareous algae. Artificial reefs such as shipwrecks are sometimes created to enhance physical complexity on generally featureless sand bottoms in order to attract a diverse assemblage of organisms, especially fish.

Biotic reef[edit]

There is a variety of biotic reef types, including oyster reefs, but the most massive and widely distributed are tropical coral reefs. Although corals are major contributors to the framework and bulk material comprising a coral reef, the organisms most responsible for reef growth against the constant assault from ocean waves are calcareous algae, especially, although not entirely, species of coralline algae.

These biotic reef types take on additional names depending upon how the reef lies in relation to the land, if any. Reef types include fringing reef, barrier reefs, as well as atolls. A fringing reef is a reef that is attached to an island. A barrier reef forms a calcareous barrier around an island resulting in a lagoon between the shore and the reef. An atoll is a ring reef with no land present. The reef front (ocean side) is a high energy locale whereas the internal lagoon will be at a lower energy with fine grained sediments.

Geologic reef[edit]

Definition[edit]

Archeocyathids, the first reef building organisms, from the Poleta formation in the Death Valley area

Geologists define reefs and related terms (for example, bioherm, biostrome, carbonate mound, pseudo-atoll) using the factors of depositional relief, internal structure, and biotic composition. There is no consensus on one universally applicable definition. A useful definition distinguishes reefs from mounds as follows. Both are considered to be varieties of organosedimentary buildups: sedimentary features, built by the interaction of organisms and their environment, that have synoptic relief and whose biotic composition differs from that found on and beneath the surrounding sea floor. Reefs are held up by a macroscopic skeletal framework. Coral reefs are an excellent example of this kind. Corals and calcareous algae grow on top of one another and form a three-dimensional framework that is modified in various ways by other organisms and inorganic processes. By contrast, mounds lack a macroscopic skeletal framework. Mounds are built by microorganisms or by organisms that don't grow a skeletal framework. A microbial mound might be built exclusively or primarily by cyanobacteria. Excellent examples of biostromes formed by cyanobacteria occur in the Great Salt Lake of Utah (USA), and in Shark Bay, Western Australia.

Cyanobacteria do not have skeletons and individuals are microscopic. Cyanobacteria encourage the precipitation or accumulation of calcium carbonate and can produce distinct sediment bodies in composition that have relief on the seafloor. Cyanobacterial mounds were most abundant before the evolution of shelly macroscopic organisms, but they still exist today (stromatolites are microbial mounds with a laminated internal structure). Bryozoans and crinoids, common contributors to marine sediments during the Mississippian (for example), produced a very different kind of mound. Bryozoans are small and the skeletons of crinoids disintegrate. However, bryozoan and crinoid meadows can persist over time and produce compositionally distinct bodies of sediment with depositional relief.

The Proterozoic Belt Supergroup contains evidence of possible microbial mat and dome structures similar to stromatolite reef complexes.[1]

Geologic reef structures[edit]

Reefs off Vanatinai in the Louisiade Archipelago.

Ancient reefs buried within stratigraphic sections are of considerable interest to geologists because they provide paleo-environmental information about the location in Earth's history. In addition, reef structures within a sequence of sedimentary rocks provide a discontinuity which may serve as a trap or conduit for fossil fuels or mineralizing fluids to form petroleum or ore deposits.

Corals, including some major extinct groups Rugosa and Tabulata, have been important reef builders through much of the Phanerozoic since the Ordovician Period. However, other organism groups, such as calcifying algae, especially members of the red algae Rhodophyta, and molluscs (especially the rudist bivalves during the Cretaceous Period) have created massive structures at various times. During the Cambrian Period, the conical or tubular skeletons of Archaeocyatha, an extinct group of uncertain affinities (possibly sponges), built reefs. Other groups, such as the Bryozoa have been important interstitial organisms, living between the framework builders. The corals which build reefs today, the Scleractinia, arose after the Permian–Triassic extinction event that wiped out the earlier rugose corals (as well as many other groups), and became increasingly important reef builders throughout the Mesozoic Era. They may have arisen from a rugose coral ancestor. Rugose corals built their skeletons of calcite and have a different symmetry from that of the scleractinian corals, whose skeletons are aragonite. However, there are some unusual examples of well preserved aragonitic rugose corals in the late Permian. In addition, calcite has been reported in the initial post-larval calcification in a few scleractinian corals. Nevertheless, scleractinian corals (which arose in the middle Triassic) may have arisen from a non-calcifying ancestor independent of the rugosan corals (which disappeared in the late Permian).

See also[edit]

Notes[edit]

References[edit]

  • Shears N.T. (2007) Biogeography, community structure and biological habitat types of subtidal reefs on the South Island West Coast, New Zealand. Science for Conservation 281. p 53. Department of Conservation, New Zealand. [1]

External links[edit]

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