[Coral-List] Palythoa overgrowing corals in Trinidad and elsewhere

Dawn Phillip Dawn.Phillip at sta.uwi.edu
Mon Mar 10 17:22:40 EDT 2008


Dear Tom

 

Oh, there are Palythoa colonies closer to shore, especially in Toco Bay.  I have just begun measuring total suspended volatile solids to try to quantify available organic particulates in the overlying water column because I suspect that the corals here have to rely on feeding for a substantial portion of their carbon requirements.

 

We also noticed that there was a lot of bleaching of the Palythoa on the reef crest - large patches of about 30 cm in diameter on some; collections of smaller (< 1 cm in diameter) of smaller white/bleached spots on others.  The Palythoa closer inshore appeared to be in better condition.

 

Dr Dawn A.T. Phillip

Lecturer

Department of Life Sciences

The University of the West Indies

St Augustine

Trinidad and Tobago

Ph: (868)662-2002 ex. 2208

Mobile: (868)394-3005; (868)464-6932

Fax: (868)663-5241

Email: dawn.phillip at sta.uwi.edu <mailto:dawn.phillip at sta.uwi.edu> 

Web: http://www.sta.uwi.edu/fsa/lifesciences/dphillip.htm <http://www.sta.uwi.edu/fsa/lifesciences/dphillip.htm> 

________________________________

From: Thomas Goreau [mailto:goreau at bestweb.net] 
Sent: Monday, March 10, 2008 5:03 PM
To: Dawn Phillip
Cc: coral-list coral-list; Jennie Mallela; Lee Ann Beddoe; Stanton Belford; João Gama Monteiro; Dan and Stephanie Clark; James Reimer; Joanna Ibrahim
Subject: Re: Palythoa overgrowing corals in Trinidad and elsewhere

 

Dear Dawn,

 

Glad to hear you and Stanton were in the field, and looking forward to your observations.  I think you will remember that we looked at the earliest studies of these sites, and Palythoa seems to have expanded landward quite a bit. The salinities are near normal, but the turbidity is extremely high for coral reefs, and I think that the Zoanthus may be able to feed of particulate organic carbon to some degree, which might give them an edge. The factors at the cold limits are presumably different, those areas are all pretty turbid too, but nothing like Trinidad!

 

Best wishes to all,

Tom

 

On Mar 10, 2008, at 4:53 PM, Dawn Phillip wrote:





Stanton and I have just come back from a trip to survey the two coral systems at Toco.  We noticed that Palythoa seemed to be dominant in specific bands on the reef, particularly on the reef crest.  It is easy to discern a Palythoa zone at low tide by looking down at the 'reef' from the top of the cliff.  Apart from overgrowing hard coral and rocks, we have seen Palythoa overgrowing Zoanthus, fire coral and anemones.

 

On a side, water salinities in this area are usually between 34 - 35 p.s.u., which does not support the hypothesis of any significant influence by the large South American rivers.

 

Dr Dawn A.T. Phillip

Lecturer

Department of Life Sciences

The University of the West Indies

St Augustine

Trinidad and Tobago

Ph: (868)662-2002 ex. 2208

Mobile: (868)394-3005; (868)464-6932

Fax: (868)663-5241

Email: dawn.phillip at sta.uwi.edu <mailto:dawn.phillip at sta.uwi.edu> 

Web: http://www.sta.uwi.edu/fsa/lifesciences/dphillip.htm <http://www.sta.uwi.edu/fsa/lifesciences/dphillip.htm> 

________________________________

From: Thomas Goreau [mailto:goreau at bestweb.net] 
Sent: Monday, March 10, 2008 1:46 PM
To: coral-list coral-list
Cc: Dawn Phillip; Jennie Mallela; Lee Ann Beddoe; Stanton Belford; João Gama Monteiro; Dan and Stephanie Clark; James Reimer
Subject: Palythoa overgrowing corals in Trinidad and elsewhere

 

Palythoa overgrowth of corals is being studied in Toco and Salybia, Trinidad, by a research group at the University of the West Indies at St. Augustine including Dawn Philip, Jennnie Mallela, Lee Ann Beddoe, and Stanton Belford. Our observations, compared to earlier work by other Trinidadian researchers, shows that Palythoa is clearly overgrowing corals and expanding over the reef flat. 

 

We see the same thing happening on a large scale in Broward County Florida, where Dan Clark and I just photographed this last week, and where large old corals are being overgrown. The same Palythoa dominance is common in southern Brazil, for example from Cabo Frio and Arraial do Cabo southwestwards. Palythoa mats dominate large areas of the reefs of Cabo Verde, and photos sent to me last week by Joao Gama Monteiro show it is even overgrowing Millepora there. 

 

Palythoa is a pest in that it is toxic so it provides neither food nor shelter, and it's spread at the expense of corals in many places is a serious concern, but the ecological factors allowing it to spread are not known. One possibility is that food supplies that Palythoa is a more effective consumer of than corals are increasing, but little is known of the feeding habits of Palythoa, according  James Reimer, a zoanthid expert I specifically asked about this a few years ago. 

 

Trinidad is an interesting exception to the general rule in that the other places where Palythoa is dominant are near the extreme cold limit of corals, which Trinidad is not, however it is near the extreme sedimentation limit of corals due to the influence of the Orinoco River. 

 

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

 

Message: 5

Date: Fri, 7 Mar 2008 16:44:43 -0400

From: "Jan-Willem van Bochove" <jvb at coralcayconservation.com>

Subject: [Coral-List] Zoanthid (Paltythoa caribaeorum) overgrowth of

            corals

To: <coral-list at coral.aoml.noaa.gov>

Message-ID: <20080307205035.40516179F5 at coral.aoml.noaa.gov>

Content-Type: text/plain;           charset="us-ascii"

 

Hello,

 

I've noticed that P. caribaeorum, a colonial zoanthid which forms extensive

mats, is overtopping and smothering a large variety of scleractinian corals

in shallow reef environments in Tobago.

 

P. caribaeorum is an aggressive, fast growing and toxic zoanthid which seems

to stop at nothing and I have yet to see any significant predation on the

species. In a small, sheltered bay where most of our observations were made,

it forms the dominant substrate with over 75% cover in the shallows (2-5m).

We have also seen it overtopping massive corals in deeper waters.

 

I was wondering if anyone has or knows of any recent research done on the

zoanthid or has noticed its abundance elsewhere on such a scale. Other than

a paper presented at the ICRS of 1981 in Manila by Suchanek and Green, I

have not come across any literature dealing with inter-specific competition

with corals.

 

 

 

Images of the zoanthid overgrowing corals can be found on -

 

 

 

http://www.flickr.com/photos/23314528@N03/

 

 

 

Any feedback is appreciated.

 

 

 

Regards,

 

 

 

Jan

 

 

 

Reference -

 

Suchanek T.H., and Green, D.J., 1981. Interspecific Competition Between

Palythoa Caribaeorum and Other Sessile Invertebrates on St.Croix Reefs, U.S.

Virgin Islands. Proceedings of the Fourth International Coral Reef

Symposium, Manila, Vol. 2.

 

-- 

Jan-Willem van Bochove MSc

Chief Technical Advisor

 

Coral Cay Conservation Ltd

Elizabeth House, 39 York Road, London, SE1 7NJ, United Kingdom

Tel: +44 (0)20 7620 1411 (switch board)

Fax: +44 (0)20 7921 0469

email: jvb at coralcayconservation.com

www.coralcay.org

skype: jhvanbochove

 

 

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

 




More information about the Coral-List mailing list