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Reef - Place Your Hands (Directors Cut)
Reef - Place Your Hands (Directors Cut)
Published: 2011/09/12
Channel: ReefVEVO
reef - Trap $piderMan (Peter Parker Diss Track)
reef - Trap $piderMan (Peter Parker Diss Track)
Published: 2017/10/03
Channel: Azerrz
Reef - Glow
Reef - Glow
Published: 2016/06/28
Channel: AMBER
Reef - Naked
Reef - Naked
Published: 2011/09/12
Channel: ReefVEVO
Reef - Consideration
Reef - Consideration
Published: 2011/07/05
Channel: ReefVEVO
Casper
Casper's Reef @ Worldwide Corals 4K Tank Tour
Published: 2018/02/04
Channel: Reef Builders
Arif - Trap $piderMan (prod. sixtyplug)
Arif - Trap $piderMan (prod. sixtyplug)
Published: 2017/10/03
Channel: A R I F
REEF | STOP
REEF | STOP
Published: 2017/06/27
Channel: Orfèvre Label
Amazing Aquariums & Reefs Lives Up To Its Name
Amazing Aquariums & Reefs Lives Up To Its Name
Published: 2018/02/10
Channel: Reef Builders
500 Gallon Reef tank Tear Down and Aquascape
500 Gallon Reef tank Tear Down and Aquascape
Published: 2018/01/12
Channel: the JaYoe Nation
CORAL REEF AQUARIUM COLLECTION • 12 HOURS • BEST RELAX MUSIC • SLEEP MUSIC • 1080p HD
CORAL REEF AQUARIUM COLLECTION • 12 HOURS • BEST RELAX MUSIC • SLEEP MUSIC • 1080p HD
Published: 2016/07/31
Channel: Cat Trumpet
Reef First Impressions - with Tom Vasel
Reef First Impressions - with Tom Vasel
Published: 2018/02/15
Channel: The Dice Tower
Reef of Riches (Documentary)
Reef of Riches (Documentary)
Published: 2016/04/08
Channel: Space Age Productions
reef *new album* Lucky #5
reef *new album* Lucky #5
Published: 2013/01/23
Channel: Greg Saveall
Reef - How I Got Over
Reef - How I Got Over
Published: 2016/02/17
Channel: Reef Band
Reef - Place Your Hands (Seaweed Sessions X LFTGR)
Reef - Place Your Hands (Seaweed Sessions X LFTGR)
Published: 2015/09/24
Channel: Live From The Green Room
Reef Life of the Andaman (full marine biology documentary)
Reef Life of the Andaman (full marine biology documentary)
Published: 2012/11/01
Channel: Bubble Vision
The 400g Reef Resetting Project
The 400g Reef Resetting Project
Published: 2017/10/16
Channel: melevsreef
#Viña2017: Así fue la presentación de las finalistas de Miss Reef
#Viña2017: Así fue la presentación de las finalistas de Miss Reef
Published: 2017/02/24
Channel: La Tercera
Reef - Good Feeling
Reef - Good Feeling
Published: 2011/09/12
Channel: ReefVEVO
Reef - I
Reef - I've Got Something To Say
Published: 2011/09/12
Channel: ReefVEVO
Coral Reefs 101 | National Geographic
Coral Reefs 101 | National Geographic
Published: 2017/11/07
Channel: National Geographic
Breaking Stuff Reef Fishing
Breaking Stuff Reef Fishing
Published: 2018/02/17
Channel: Key West Kayak Fishing
Reef - Come Back Brighter (Black and White Earth Version)
Reef - Come Back Brighter (Black and White Earth Version)
Published: 2011/09/12
Channel: ReefVEVO
Sanjay 500 Gallon Mega Reef - Extended
Sanjay 500 Gallon Mega Reef - Extended 'Reef Nerd' Edition +10 Minutes
Published: 2017/09/18
Channel: Reef Builders
REEF | MERCI
REEF | MERCI
Published: 2017/04/17
Channel: Orfèvre Label
Great Barrier Reef | Exploring Oceans
Great Barrier Reef | Exploring Oceans
Published: 2009/03/30
Channel: National Geographic
ARIF - Walk (Young M.A Remix)
ARIF - Walk (Young M.A Remix)
Published: 2017/11/07
Channel: A R I F
Coral Reef Aquarium & The Best Relax Music - 2 Hours - Sleep Music - HD 1080P
Coral Reef Aquarium & The Best Relax Music - 2 Hours - Sleep Music - HD 1080P
Published: 2016/03/07
Channel: BaLu - Relaxing Nature
Reef - Mellow
Reef - Mellow
Published: 2008/12/01
Channel: Chiisanamado
RALPH
RALPH'S REEF - EPIC REEF TANK IN AMSTERDAM!!
Published: 2017/09/13
Channel: George Farmer
Subnautica #10 : Secrets du Grand Reef !
Subnautica #10 : Secrets du Grand Reef !
Published: 2018/02/14
Channel: Aurelien_Sama
3 Year Anniversary of my reef
3 Year Anniversary of my reef
Published: 2016/11/11
Channel: melevsreef
David Attenborough - Great Barrier Reef - 1/3 [HD]
David Attenborough - Great Barrier Reef - 1/3 [HD]
Published: 2017/09/12
Channel: ukfpjd
CORAL REEF AQUARIUM COLLECTION • 12 HOURS • BEST RELAX MUSIC • SLEEP MUSIC • 1080p HD #2
CORAL REEF AQUARIUM COLLECTION • 12 HOURS • BEST RELAX MUSIC • SLEEP MUSIC • 1080p HD #2
Published: 2017/02/17
Channel: Cat Trumpet
Reef Iwagumi || UNBELIEVABLE Reef Aquarium HD
Reef Iwagumi || UNBELIEVABLE Reef Aquarium HD
Published: 2015/12/24
Channel: CoralFish12g
Azerrz A.K.A REEF - Trap $piderMan (Peter Parker DISS TRACK) REACTION!!!
Azerrz A.K.A REEF - Trap $piderMan (Peter Parker DISS TRACK) REACTION!!!
Published: 2017/10/04
Channel: Dwayne N Jazz
REEF TANK ADDICTION - SEASON 4 EPISODE 1
REEF TANK ADDICTION - SEASON 4 EPISODE 1
Published: 2018/02/17
Channel: LEOPAZZO TV
Reef  - Set the Record Straight
Reef - Set the Record Straight
Published: 2009/12/27
Channel: total13
Clean Up on Isle 3rd reef MAVERICKS - Edit by Dom Padua
Clean Up on Isle 3rd reef MAVERICKS - Edit by Dom Padua
Published: 2018/02/15
Channel: Powerlines Productions
We Built a Reef Aquarium For Only $275. Here
We Built a Reef Aquarium For Only $275. Here's How We Did It!
Published: 2017/06/16
Channel: Marine Depot Aquarium Supplies
Life On The Coral Reef [HD]
Life On The Coral Reef [HD]
Published: 2014/01/20
Channel: Beyond The Water Surface
Mike
Mike's Killer Nano Reef Tank
Published: 2017/06/07
Channel: Reef Builders
Is The Great Barrier Reef Actually Dead?
Is The Great Barrier Reef Actually Dead?
Published: 2017/11/26
Channel: Seeker
Great Barrier Reef, Australia
Great Barrier Reef, Australia
Published: 2015/10/06
Channel: Queensland, Australia
NANO REEF OVERLOAD!! Five Great Nano & Pico Reefs At Elite Reef
NANO REEF OVERLOAD!! Five Great Nano & Pico Reefs At Elite Reef
Published: 2017/06/11
Channel: Reef Builders
REEF | DEMONS
REEF | DEMONS
Published: 2017/09/25
Channel: Orfèvre Label
The Great Barrier Reef May Be Dying Faster Than We Thought | National Geographic
The Great Barrier Reef May Be Dying Faster Than We Thought | National Geographic
Published: 2017/03/20
Channel: National Geographic
crossing razor sharp OYSTER REEF to fish secret spot
crossing razor sharp OYSTER REEF to fish secret spot
Published: 2018/02/16
Channel: ThresherFishing
500 GALLON REEFTANK, AQUARIUM LIGHTING, FRAG TANKS
500 GALLON REEFTANK, AQUARIUM LIGHTING, FRAG TANKS
Published: 2017/04/21
Channel: the JaYoe Nation
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WIKIPEDIA ARTICLE

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Nusa Lembongan Reef, Bali, Indonesia.
Pamalican island with surrounding reef, Sulu Sea, Philippines.
A reef surrounding an islet.

A reef is a bar of rock, sand, coral or similar material, lying beneath the surface of water. Reefs may go as deep as 261 feet (80 m) below the surface.[citation needed]

Many reefs result from abiotic processes (i.e. 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 (e.g. shipwrecks) sometimes have a role in enhancing the physical complexity of featureless sand bottoms, in order to attract a diverse assemblage of organisms, especially algae, and 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]

One 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]

References[edit]

Notes[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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