[Coral-List] Set the Diadema loose!

Thomas Goreau goreau at bestweb.net
Sun Jan 20 12:12:08 EST 2008 

Dear Todd,

Thanks for these observations. The rapid spread of cyanobacteria may  
be helped along by the refusal of Diadema to eat it, eventually  
resulting in Diadema starving out. The surgeon fish seem to avoid the  
cyanobacteria in Barbados too.

Dan and Stephanie Clark who worked with volunteer divers to haul huge  
masses of cyanobacteria of reefs in Broward County, Florida, a few  
years ago, found them full of some sort of thin white worms........

Best wishes,
Tom


On Jan 20, 2008, at 11:38 AM, Todd Barber wrote:

> Hi Tom,
>
> Just my two cents worth but Diadema will not eat cyanobacteria.   
> (At least in captivity even when there are no other food sources  
> present. My experiance is with the red and near black varieties of  
> cyanobacteria).
>
> -Todd
>
>
>
>
>
> ----- Original Message ----- From: "Thomas Goreau"  
> <goreau at bestweb.net>
> To: "Martin Moe" <martin_moe at yahoo.com>
> Cc: "coral-list coral-list" <coral-list at coral.aoml.noaa.gov>; "Reef  
> Rescue" <Etichscuba at aol.com>; "Henry Breck" <hrbreck at the-ark.com>;  
> "Eliane Polack" <elianepolack at caribserve.net>
> Sent: Saturday, January 19, 2008 10:03 AM
> Subject: [Coral-List] Set the Diadema loose!
>
>
> Dear Martin,
>
> Andrew Ross says that at Doctors Cave near Montego Bay, Trididemnum
> solidum and Echinometra occur in the same habitat, but are mutually
> exclusive, so maybe there is something to this.....
>
> It will be very interesting to use your pet Diadema herd for targeted
> experiments! I really hope that they eat every bit of Trididemnum
> solidum that they encounter, but I wonder if it is just too toxic for
> them. One of our reef restoration sites, in Sint Maarten, has very
> dense Diadema populations, and there is Trididemnum solidum there
> too, but not yet too bad.....
>
> Another place where you need to set your Diadema loose and see what
> they do, is on the slimy cyanobacteria that is taking over wherever
> there is much nutrients from sewage and other sources. SE Florida has
> vast patches of this killing corals , spreading outward from the
> sewage outfalls, and waxing and waning as they change the amount of,
> ummm, ordure (Jim, that's not a banned word yet is it?), that they
> pump out, as Ed Tichenor has definitively shown.
>
> Wayne Hunte told me in 1994 that Diadema had recovered to around two
> thirds of their pre 1983 densities in Barbados, and you could see
> that they and the huge parrotfish everywhere (which Bajans don't
> eat)  got rid of the macrophytes but could not control the turf that
> was eaten and grew back every day. In the last 5-6 years (according
> to Angelique Brathwaite of the Barbados Coastal Zone Management Unit)
> the turf has disappeared, and been replaced by slimy cyanobacteria
> (not the same one killing SE Florida reefs and the areas around the
> dolphin pens in Cozumel, another species), and the Diadema have again
> disappeared. The parrotfish don't seem to touch the stuff, and I'm
> wondering if the new disappearance of Diadema is another plague or if
> they have been starved out because they won't touch the main algae
> that is there now?
>
> By the way, despite much urban mythology, Diadema die off had nothing
> to do with the spread of algae over the reef in Jamaica, which was
> caused by eutrophication that coincidentally occurred spanning the
> Diadema die off in the Discovery Bay area, but which happened long
> before and long after in other parts of Jamaica:
> T. J. Goreau, 1992, Bleaching and reef community change in Jamaica:
> 1951-1991, in SYMPOSIUM ON LONG TERM DYNAMICS OF CORAL REEFS,
> AMERICAN ZOOLOGIST, 32: 683-695.
>
> Best wishes,
> Tom
>
>
> On Jan 19, 2008, at 9:04 AM, Martin Moe wrote:
>
>> I might be able to do this, I have a brood stock of 19 large and
>> healthy Diadema and it would be possible to collect a bit of
>> Trididemnum and see what happens to it in the tank. The result
>> wouldn't be directly applicable to what might happen on the reef,
>> but it would be a clue. If I get a chance to do this, I'll let you
>> know what happens.
>>
>> Martin
>>
>> ----- Original Message ----
>> From: Thomas Goreau <goreau at bestweb.net>
>> To: andrew ross <andyroo_of72 at yahoo.com>
>> Cc: Martin Moe <martin_moe at yahoo.com>
>> Sent: Thursday, January 17, 2008 5:20:33 PM
>> Subject: Re: [Coral-List] tunicates
>>
>> Echinometra does not go deep enough to be in Tridemnum habitat.
>>
>> I very much doubt the Diadema control hypothesis, but it would be
>> interesting to put some Diadema on a bit of Trididemnum and see
>> what happens. I hope Martin can try this.
>>
>>
>>
>>
>> On Jan 17, 2008, at 3:29 PM, andrew ross wrote:
>>
>>> I'm not seeing this tunicate on Echinometra viridis
>>> colonized/cleaned reef areas. Areas without this
>>> urchin/with (plenty of) algae loaded with it. Diadema
>>> control makes sense.
>>> Also Echinometra areas have less/no boring sponges
>>> either.
>>> Andrew
>>>
>>>
>>> --- Martin Moe <martin_moe at yahoo.com> wrote:
>>>
>>>>
>>>>
>>>> I've been following the tunicate thread with great
>>>> interest.
>>>> Seems that what's needed to keep them under control
>>>> would be an organism that
>>>> actually cleans the rock, something that can scrape
>>>> and feed on just about anything
>>>> that is attached to the upper levels of the
>>>> substrate, something that even if
>>>> it couldn't actually consume the organism itself
>>>> might be able to keep its
>>>> growth in check and keep it from invading open
>>>> substrates. Too bad that
>>>> there isn't anything like that on the western
>>>> Atlantic reefs today, at least
>>>> not in numbers adequate to do this housekeeping over
>>>> extensive areas. But wait,
>>>> maybe Diadema could do that job, as well keep algae
>>>> growth under control, if
>>>> they were abundant once again.  Diadema may
>>>> or may not have had an impact on tunicate growth
>>>> when they were abundant, I have not seen any studies
>>>> on that, but they
>>>> were so critical in shaping and maintaining the
>>>> ecology of these reefs over
>>>> great expanses of time that their loss has
>>>> implications for the reefs far
>>>> beyond just algae control. There could be an
>>>> interesting graduate thesis in such a study. Too be
>>>> sure, return of Diadema wouldn’t solve all
>>>> the problems facing these reefs in these perilous
>>>> times, but if Diadema could
>>>> be returned to the reefs, they would be an essential
>>>> element to whatever ecological restoration
>>>> of our coral reefs is possible.
>>>>
>>>> Martin Moe
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
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>>>>
>>> http://coral.aoml.noaa.gov/mailman/listinfo/coral-list
>>>>
>>>
>>>
>>>
>>>
>>> ____________________________________________________________________ 
>>> _
>>> _______________
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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
>>
>>
>>
>
> 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
>
> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov
> http://coral.aoml.noaa.gov/mailman/listinfo/coral-list

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

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