[Coral-List] Strange Xestospongia muta damage

[Thomas Goreau]

Dear Kristen,

No, I did not dive at the area that you and the VONE Research Team  
surveyed which was damaged by cables off Pompano. Dan  Clark and I  
were diving on the first reef off Fort Lauderdale in places that had  
no obvious physical damage. Nor did we see fishing line around any of  
them, as Joseph Pawlik has documented in the Florida Keys. These  
sponges were not simply ripped up or scraped, they looked as though  
they had been cut flat parallel to the substrate with a very sharp  
knife and very sure hand. It was bizarre. I know that it would take a  
very large, very sharp knife with tremendous force to do this. The  
tissue was growing over the flat portions from both inside and  
outside, some more than others, and I believe that most recovered.  
The local divers know much more about this than I do, especially Jeff  
Torode and Dan Clark, I was merely confirming their observations. It  
is possible that Dan or Jeff have photographs. I'm completely baffled  
as to how this could have happened.

Best wishes,
Tom

On Apr 30, 2008, at 7:54 AM, Kristen Hoss wrote:

> Hello,
>
> Are you referring to the cable drag that occurred and sawed off 27  
> acres of reef a while back?  What you are describing is exactly  
> what happened during a dredging project off the coast of Pompano  
> Beach, FL and many of the sites were repaired. However, the severed  
> sponges did not fare as well as the corals and much of the  
> restoration on those sponges failed. That left behind what you are  
> describing.
>
> -Kristen Hoss
> Vone Research
>
> Thomas Goreau <goreau at bestweb.net> wrote:
> Estimado Glauco,
>
> Several years ago in Broward County local divers began noticing
> Xestospongia muta that looked as if they had been cut off flat near
> the bottom as if cut with razor wire. It was so common that local
> divers thought someone was stealing their big sponges, unlikely as
> that seems. I saw them myself with Dan Clark, and there was no
> jagged edge as would happen with a knife cut, anchor dragging, or
> turtle chomping, but luckily almost all were healing. I've taken
> samples of diseased Xestospongia in the past for microbial analysis,
> and know how hard it is to cut a small piece out of them, even of
> necrotic tissue, so we were baffled. Luckily there was a short
> intense episode of this damage, and it does not seem to have
> recurred. Who, why, or when are mysterious, but at least we know  
> where.
>
> Saludos,
> Tom
>
>
> Thomas J. Goreau, PhD
> President
> Global Coral Reef Alliance
> 37 Pleasant Street, Cambridge MA 02139
> 617-864-4226
> goreau at bestweb.net
> http://www.globalcoral.org
>
> Date: Sun, 27 Apr 2008 15:04:06 -0400
> From: glauco150 at aol.com
> Subject: [Coral-List] Xetospongia muta
> To: coral-list at coral.aoml.noaa.gov
> Message-ID: <8CA76B0998FBB32-BAC-4281 at mblk-d30.sysops.aol.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Dear listers:
>
> During a recent dive?(75-80 ft deep) in the north coast of Puerto
> Rico I found out?numerous Xetospongia muta totally or partially
> broken.??Some sponges broke flush to the substrate, others broke in
> different angle when compared to the next standing; there was not a
> clear break pattern.??On March 20-22, Puerto Rico and the USVI coasts
> received the impact of a powerful cold front?which produced 30-plus
> feet breaking waves causing significant coastal erosion.? Could it be
> possble that soft or weak areas of large high profile?X. muta did not
> resisted?such continuous?high energy swell/surge?
>
> I will appreciate any comments or references.
>
> best regards,
>
> Glauco A Rivera
> PhD candidate
> Univ. of PR-Dept. of Marine Sciences
>
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Thomas J. Goreau, PhD
President
Global Coral Reef Alliance
37 Pleasant Street, Cambridge MA 02139
617-864-4226
goreau at bestweb.net
http://www.globalcoral.org