[Coral-List] Hawskbill turtles predating corals

Terri Young tyoung at icran.org
Tue May 13 13:25:01 EDT 2008

Hi David,

I have also frequently observed this behaviour with Hawksbills around the
Phi Phi islands in Thailand. In some cases selective grazing was evident
where the turtle was observed moving between Physogyra colonies. 

Terri Young
International Coral Reef Action Network (ICRAN)
219 Huntingdon Road
Cambridge, CB3 0DL
United Kingdom
T: +44 1223 277314  xt: 269
F: +44 1223 277 136
Skype id: teripang
tyoung at icran.org

Today's Topics:

   1. Re: Hawskbill turtles predating corals (William Allison)
   2. Re: White spined diadema (Martin Moe)
   3. Re: White-spined Diadema antillarum (Barbara Whitman)
   4. Re: Coral bleaching in the western pacific warm pool. (Mark Eakin)


Message: 1
Date: Mon, 12 May 2008 08:25:39 -0400
From: "William Allison" <allison.billiam at gmail.com>
Subject: Re: [Coral-List] Hawskbill turtles predating corals
To: "David Obura" <dobura at africaonline.co.ke>
Cc: "coral-list at coral.aoml.noaa.gov" <coral-list at coral.aoml.noaa.gov>
	<1eab821b0805120525x63ca90abm1e72739ba45ce87b at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Hi David,
I observed this behaviour once in Maldives where I have also seen hawksbills
grazing on false corals.

On Sat, May 10, 2008 at 3:14 PM, David Obura <dobura at africaonline.co.ke>

> Hi all,
> While in Aldabra and Alphonse islands (Seychelles) I noted a
> behaviour/effect of hawskbill turtles that I've never heard mentioned
> before. I had noted dead patches/scars on a bubble coral in the genus
> Physogyra that were widespread, though not covering a large proportion of
> the coral. I was watching a hawksbill turtle swimming out from behind one
> of
> these heads and noticed that it had tissue in its mouth, and it bent down
> and took a bite from the coral. I then observed the same behaviour and
> coral-scars on Alphonse.
> Has anyone reported hard coral tissue in hawksbill gut contents, or damage
> to corals from turtle predation? I'm intrigued, as though the impact was
> not
> huge to the corals, this was definitely a stable food source for the
> turtles, and impact on the corals.
> Best,
> David Obura
> CORDIO East Africa
> 9 Kibaki Flats, Kenyatta Public Beach
> P.O.BOX 10135 Mombasa 80101, Kenya
> Tel/fax: +254-20-3548549; mobile 0733-851656
> dobura at cordioea.org, dobura at africaonline.co.ke
> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov
> http://coral.aoml.noaa.gov/mailman/listinfo/coral-list


Message: 2
Date: Mon, 12 May 2008 06:31:28 -0700 (PDT)
From: Martin Moe <martin_moe at yahoo.com>
Subject: Re: [Coral-List] White spined diadema
To: Robert Miller <rjmiller1 at gmail.com>, John Ware <jware at erols.com>
Cc: coral-list at coral.aoml.noaa.gov
Message-ID: <961181.54894.qm at web42105.mail.mud.yahoo.com>
Content-Type: text/plain; charset=us-ascii

On white spined Diadema,
I've seen and collected numerous white spined Diadema. The cause and
occurrence of the white spines is not clear to me. I know that on the arms
of the urchin, yes, they have arms, sort of. On the test there are 5
triangular plates, the ambulacral plates, that are like the 5 arms of a
starfish but as if they were folded up from the aboral pole and fused into
the spherical body. The tube feet of the urchin are located on the edges of
these plates. The spines that originate on these ambulacral plates and the
spines that originate from the interambulacrum areas are generally
indistinguishable during the day, but at night the spines on the 5
ambulacral plates are usually white or whitish and give the urchin a sort of
striped look. This the nocturnal color phase. Juveniles have spines with
variable dark and white ringed spines. From working with my brood stock, I
got the impression that it is the older individuals that seem to retain the
nocturnal coloration
 during the day. In my brood stock I have two individuals that permanently
retain white spines on the ambulacral plates, these two are males....  But
there are other males that do not retain the nocturnal coloration. And I
have collected some individuals with all brilliant while spines, from not
particularly deep in the reef, and with "normally" dark purple colored
individuals in the same area. I have had individuals that were all white on
collection become dark after a time in the brood stock tank and some that
permanently retain full or partial white coloration for a year or
more.Usually it is the larger (older?) individuals that exhibit partial or
total white spines, but some smaller individuals also have this coloration.
Also, the incident of white spined individuals seems to vary in different
areas of the reef. Some areas seem to have considerably more individuals
with partial or full white spine coloration than other areas.
So, basically, some Diadema, a relatively small percentage, have a permanent
or long term, all or partial white spine coloration, and I don't know why
this is so.....

Martin Moe

----- Original Message ----
From: Robert Miller <rjmiller1 at gmail.com>
To: John Ware <jware at erols.com>
Cc: coral-list at coral.aoml.noaa.gov
Sent: Saturday, May 10, 2008 1:34:00 PM
Subject: Re: [Coral-List] White spined diadema

Hi,Somewhere out there is an old study that showed, I believe, that juvenile
Diadema that were raised in the dark were all white.  Other studies have
shown, as John Ware says, that more white ones are found deeper and under
rocks etc.  Unfortunately I don't have the references now.
good luck,

On Fri, May 9, 2008 at 10:06 AM, John Ware <jware at erols.com> wrote:

> Stuart,
> I was hoping that someone who had firm knowledge would respond, because
> my memory is old and feeble.  Some 15 or 20 years ago I read a paper
> (which I cannot recall or find) that stated that the white-spined D.a.
> were more often found in low visibility environments.  At least that is
> my recollection.
> John
> Stuart P. Wynne wrote:
> >Dear all,
> >
> >
> >
> >I have been trying to find references to the white spined Diadema
> >antillarum that I sometimes see in our waters here in Anguilla. As I am
> >not privy to open access (but please let us not get onto that subject
> >again!) I have been struggling to find any mention of the causes for
> >this, only the fact that it is a fairly common thing to see. I guess it
> >is a lack of pigment? As all such individuals I've seen here are large,
> >could it be something that signifies they are reaching old age? Does it
> >indicate a lack of something in their diet? Pollution/eutrophication? If
> >anyone has any ideas/knowledge I would love to learn.
> >
> >
> >
> >On a separate note I would like to send out a big thank you to the three
> >people who posted on the coral-list vol 59 issue 6. For the first time
> >since I have been a member I did not have to wade through endless reams
> >of old postings (that had been left tagged to the bottom of their entry)
> >while trying to figure out which messages were the new messages. Well
> >done! Maybe we can keep this up?
> >
> >
> >
> >
> >
> >Stuart Wynne
> >Marine Biologist
> >Department of Fisheries and Marine Resources
> >Anguilla
> >
> >
> >
> >
> >
> >
> >
> >
> >Government of Anguilla
> >_______________________________________________
> >Coral-List mailing list
> >Coral-List at coral.aoml.noaa.gov
> >http://coral.aoml.noaa.gov/mailman/listinfo/coral-list
> >
> >
> >
> --
>    *************************************************************
>    *                                                           *
>    *                      John R. Ware, PhD                    *
>    *                         President                         *
>    *                      SeaServices, Inc.                    *
>    *                   19572 Club House Road                   *
>    *             Montgomery Village, MD, 20886, USA            *
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>    *                http://www.seaservices.org                *
>    *                     fax: 301 987-8531                     *
>    *             Treasurer and Member of the Council:          *
>    *            International Society for Reef Studies         *
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Robert J. Miller
Marine Science Institute
University of California, Santa Barbara
Santa Barbara CA 93106-6150
(805) 893-7295
Coral-List mailing list
Coral-List at coral.aoml.noaa.gov


Message: 3
Date: Mon, 12 May 2008 11:34:52 -0400
From: "Barbara Whitman" <terramar at caribcable.com>
Subject: Re: [Coral-List] White-spined Diadema antillarum
To: <coral-list at coral.aoml.noaa.gov>,	"Gordon Hendler"
	<hendler at nhm.org>
Message-ID: <54854ECCE0F94C03AF6CF4B06DF15943 at BarbaraWhitmPC>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";

I have had individuals in my aquariums that were originally all black-spined

but did end up with some white spines.  My aquariums are directly linked to 
the Caribbean and sometimes during a surge they bring in fine sediments so 
perhaps that had something to do with it..  I have also had small Diadema 
which were all black. The black coloring does come off the spines sometimes 
if you touch them - which unfortunately I do fairly often when cleaning the 
tanks. I have not noticed a difference in their coloring between day and 
night and when the water is clean opposed to when there are fine sediments 
making the water more murky but I will pay more attention now.

Barb Whitman
Under the Sea Sealife Education Centre
Nevis, West Indies

----- Original Message ----- 
From: "Gordon Hendler" <hendler at nhm.org>
To: <coral-list at coral.aoml.noaa.gov>
Sent: Monday, May 12, 2008 12:32 AM
Subject: Re: [Coral-List] White-spined Diadema antillarum

> According to Moore (1966:81) large Diadema antillarum with some or many
> white or gray spines "...are found in darker and more turbid conditions 
> and
> frequently in caves. In my experience, they seem to be more common in deep
> water around Caribbean reefs than at shallow depths. The spines of
> juveniles are always banded with black and white. Individuals change color
> in response to the intensity of illumination. Animals that are black 
> during
> the day pale at night.
> Hendler et al. 1995. Sea Stars, Sea Urchins, and Allies. Echinoderms of
> Florida and the Caribbean. Smithsonian Institution Press. 390 pp.
> Moore, H.B. Ecology of echinoids. In: Physiology of Echinodermata, ed. 
> R.A.
> Boolootian, 73-85. John-Wiley Interscience. N.Y.
> ********************************************
> Gordon Hendler, Ph.D.
> Curator of Echinoderms
> Natural History Museum of Los Angeles County
> 900 Exposition Boulevard
> Los Angeles, California 90007 U.S.A.
> Voice:  213 763 3526
> Fax:    213 746 2999
> ********************************************
> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov
> http://coral.aoml.noaa.gov/mailman/listinfo/coral-list 


Message: 4
Date: Mon, 12 May 2008 11:51:40 -0400
From: Mark Eakin <Mark.Eakin at noaa.gov>
Subject: Re: [Coral-List] Coral bleaching in the western pacific warm
To: Ruben van Hooidonk <rubski at gmail.com>
Cc: coral-list at coral.aoml.noaa.gov
Message-ID: <8167A324-038E-41B2-B46B-642D634A5692 at noaa.gov>
Content-Type: text/plain;	charset=US-ASCII;	delsp=yes;

You should look at a recent paper by Kleypas et al. on this subject:

Kleypas, Joan A., Gokhan Danabasoglu, and Janice M. Lough (2008)  
Potential role of the ocean thermostat in determining regional
differences in coral reef bleaching events. GEOPHYSICAL RESEARCH  
LETTERS, VOL. 35, L03613, doi:10.1029/2007GL032257.


On May 7, 2008, at 5:24 PM, Ruben van Hooidonk wrote:

> Hi,
> During research on thermal coral bleaching in the western pacific  
> warm pool,
> I noticed that observations of coral bleaching in that region are very
> limited in the reefbase.org database. I would like to know if  
> anyone knows
> of any bleaching episodes not recorded in that database.
> You can see the location of the warm pool here:
> http://roskilde.eas.purdue.edu/~ruben/wpwp.jpg
> If you know of any observations of bleaching in that region, please to
> submit your data on the form that can be found here:
> http://roskilde.eas.purdue.edu/~ruben/bleaching_in_WPWP.php
> Thank you very much for your help, and if you have any questions or  
> remarks
> please ask me directly,
> Ruben van Hooidonk
> Purdue University
> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov
> http://coral.aoml.noaa.gov/mailman/listinfo/coral-list

C. Mark Eakin, Ph.D.
Coordinator, NOAA Coral Reef Watch
National Oceanic and Atmospheric Administration
Center for Satellite Applications and Research
Satellite Oceanography & Climate Division
e-mail: mark.eakin at noaa.gov
url: coralreefwatch.noaa.gov

E/RA31, SSMC1, Room 5308
1335 East West Highway
Silver Spring, MD 20910-3226
301-713-2857 x109                   Fax: 301-713-3136


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