[Coral-List] What is a coral reef and where is it's edge?

Clifford J. Hearn clifford_hearn at yahoo.com
Fri Aug 30 06:07:12 EDT 2013

One quantity which we have found is totally unique to a coral assemblage is the variance of depth which is determined in a way shown by Zawada et al (2011) in GRL and is essentially the topographic complexity. It never lies and is a perfect predictor of coral, or topography that has been shaped by coral, as shown in my 2011 paper in the journal Coral Reefs.
Clifford J. Hearn
Working Science Consultancies 
In setting up the original, data-repository version of ReefBase, we had to
deal with a lot of conflicting definitions. We finally decided that there
were 'true' geostructural reefs, and informal 'coral reefs' which were coral
communities not associated with significant calcium carbonate deposition.
There were also 'sub-reef units' which include the 'patch reefs' to which
many refer, which are really bommies and coral patches within large reefs
such as atolls (there are also 'real' patch reefs not within other reefs). 

As Veron pointed out in his plenary in the Japan ICRS, there is only a loose
relationship between coral reefs and corals. Corals grow on lots of hard
substrates, including fallen trees. Exposed bedrock supports lots of coral
communities in Ambon Bay (McManus and Wenno 1981 Bull Mar Sci). Similar
growths occur on sandstone substrates in Sri Lanka. Many coral communities
sit on boulders and lava flows. Tom Goreau Sr. and others used to
distinguish between true coral reefs and coral communities not on reefs.
Spalding et al. "Coral Reefs of the World" used the stricter definition of a
coral reef being wave-breaking, but extended their boundaries a bit to
broaden their area estimates. John Munro considered a "coral reef"  to be
bounded by the limits of where predatory reef fish would swim -- the shelf
of Jamaica was one reef to him--including the large bank to the south. Both
Smith and Kleypas' area estimates attempted to account for both
geostructural reefs and non-geostructural coral communities. This helps
explain why Spalding et. al estimated only half of what Smith and Kleypas
(in her best estimate) had estimated. Because of the wide ranging behavior
of some reef fish away from dense coral communities, John Munro had much
higher estimates for just the Caribbean. 

Kleypas, McManus and Menez 1999 (Amer Zool) looked at the hundreds of coral
community and reef descriptions we had compiled in ReefBase, and found
geographic (and calcium carbonate saturation level) bounds to where
geostructural reefs were likely to have developed. Now that the saturation
levels are known to be changing, some people have incorrectly assumed that
many of those reefs are now dead -- not accounting for the fact that huge
accumulations of calcium carbonate will take hundreds to thousands of years
to wear down under present conditions. Additionally, the limits were about
net deposition, not coral growth. There is now increasing evidence that reef
communities, sand and substrates can locally buffer the impacts of ocean
acidification (unless there is a shift to algal dominance), further slowing
the loss of these reefs (see recent papers by Anthony, Kleypas, and others).

Finding the 'boundaries' of a non-geostructural coral community is
fascinating problem I spent years pondering. I suggest using the 'bounding
lines' approach used in international Law of the Sea to define island
archipelagos and their internal waters. In other words, a definition of area
or perimeter would be meaningful for a particular size of bounding lines. 

So, definitions are hugely important, and the misunderstanding of
definitions has been a major hold-up to the advancement of coral reef



John W. McManus, PhD.
Professor, Marine Biology and Fisheries
Director, National Center for Coral Reef Research (NCORE)
Rosenstiel School of Marine and Atmospheric Science (RSMAS)
University of Miami. Phone: 305-421-4814
Website: http://www.rsmas.miami.edu/people/faculty-index/?p=john-mcmanus
NCORE Website: http://ncore.rsmas.miami.edu/

"If I cannot build it, I do not understand it." -- Richard Feynman, Nobel


Message: 3
Date: Wed, 28 Aug 2013 21:24:36 -0400
From: "Keven Reed" <reedkc at comcast.net>
Subject: Re: [Coral-List] Distressing news for the whole Pacific
To: "MelissaE Keyes" <melissae.keyes at yahoo.com>
Cc: coral-list at coral.aoml.noaa.gov
Message-ID: <29AABFD58CA545F182B7CA081FA2D89B at VALUED664B84C7>
Content-Type: text/plain;    charset="utf-8"

Dear Melissa and younger coral-listers,

    To add to Professor Szmant's post and perspective, many Americans have forgotten that tourists used to go to the upper floors of the Las Vegas hotels to glimpse mushroom clouds north of Las Vegas.  I was within 500 miles of 100 nuclear atmospheric tests/explosions by age 11 between early 1951 to July 17, 1962.  The plutonium tests started in 1955.  I was fortunate to live west of the Sierra Nevadas and north of Nevada in southern Idaho during most of those years, so I was usually upwind so to speak.

    This perspective is not to diminish the mistakes of the past or the present or anyone's suffering in Japan or in the desert southwestern USA, but I agree with Alina that one does not need to panic about their personal safety if they are living on the New World/American continents.  My wife is Japanese, BTW.  While cesium in plants and milk around the world is a concern, just do the math & physics, convert the rads/rems (the old units I grew up on) in to the newer SI units of Grays (Gy).  Approx' 400 rads or rems of gamma equal approx' 4 Gy.

    While 8 Gy whole body absorption is 100% fatal for humans, we routinely treat tumors with focused energy beams in the tens of Grays!

Fukushima is a very serious environmental problem, but look at the actual numbers on the radiation detectors on our West Coast before climbing out of one's skin.  Remember there are places in states like Maryland and Pennsylvania where one has to place a radiation detector to measure the natural background radiation from the rocks around a basement before closing a real estate deal on a private home sale.

Thanks for bringing this matter to everyone's consciousness again.


Keven C. Reed in Fleming Island, FL
  ----- Original Message ----- 
  From: MelissaE Keyes 
  To: coral-list at coral.aoml.noaa.gov 
  Sent: Monday, August 26, 2013 12:38 PM
  Subject: [Coral-List] Distressing news for the whole Pacific Ocean.

  Hello, Listers,

  I dislike sending this, but I feel it is important information. Quoted from:


  The heart-breaking news from Fukushima just keeps getting worse?a LOT worse?it is, quite simply, an out-of-control flow of death and destruction. TEPCO is finally admitting that radiation has been leaking to the Pacific Ocean all along. and it?s NOT over?.

  It now appears that anywhere from 300 to possibly over 450 tons of contaminated water that contains radioactive iodone, cesium, and strontium-89 and 90, is flooding into the Pacific Ocean from the Fukushima Daichi site everyday. To give you an idea of how bad that actually is, Japanese experts estimate Fukushima?s fallout at 20-30 times as high as as the Hiroshima and Nagasaki nuclear bombings in 1945.

  Map at the above available in the article in the link.


  Melissa Keyes
  Melissa E. Keyes
  St. Croix, 
  U.S.Virgin Islands
  Coral-List mailing list
  Coral-List at coral.aoml.noaa.gov


Message: 4
Date: Thu, 29 Aug 2013 08:47:24 +0000
From: Rebecca Short <Rebecca.Short at zsl.org>
Subject: [Coral-List] Reef Conservation UK Conference 2013
To: Coral List <coral-list at coral.aoml.noaa.gov>
Message-ID: <FB733323541A7B4DB195B0A9175824C345A0A7E2 at ZSL82.zsl.org>
Content-Type: text/plain; charset="iso-8859-1"

Hello all,

We are pleased to announce details of the 2013 Reef Conservation UK conference to be held at ZSL, Regent's Park, London on the 7th December 2013.

As ever, the meeting will strive to bring together a multi-disciplinary group and facilitate discussion and sharing of knowledge on global reef conservation initiatives, advances and needs. It is consequently expected to be an excellent networking opportunity and, now in its 16th year a chance to continue to forge effective partnerships and collaborations.

A day of presentations will be interspersed with poster sessions and rounded off with a drinks reception in the ZSL London Zoo aquarium.

All interested parties are invited to submit a title and abstract (max. 300 words) for an oral presentation or poster to rcuk at zsl.org<mailto:rcuk at zsl.org> by  19th October. Please see the website for more details at www.zsl.org/rcuk<http://www.zsl.org/rcuk>.

Online registration will follow shortly at the same web address. We will update you when this is available but the registration deadline will be 29th November and conference costs will be ?30 for students and ?35 for all others, to include refreshments, lunch and the drinks reception.

As the RCUK initiative evolves we are constantly striving to update our ability to facilitate communication, year round. As such we would like to invite you and your colleagues to join the new RCUK google group at https://groups.google.com/d/forum/rcuk.This we hope will allow the UK community of interested organisations and individuals to share discussions from and apart from the annual conference, and allow us to update you on future events. Please sign up and join in!

This year we will also be sending out updates and information via twitter. We will hash tag all relevant tweets with #RCUK2013 and hope all fellow tweeters will do the same.

Please circulate to your networks and we hope to see you all in December!

Many thanks and feel free to get in touch should you have any questions,


On behalf of the RCUK committee

Rebecca Short
Marine & Freshwater Programme Co-ordinator

Conservation Programmes
Zoological Society of London
Regent's Park
0207 449 6480

rebecca.short at zsl.org<mailto:rebecca.short at zsl.org>
Skype: rebecca.short86


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