[Coral-List] Underwater sculptures: why are they covered with alage?

[savecoralnow]

Why not add ample doses of copper and zinc sulphate to the concrete mix? Doing
so may very well curb the algae for quite some time although I doubt it will
do corals any justice.

JS...


On 07/08/2012 10:27 PM, Szmant, Alina wrote:
> My guess is that lack of grazing much more than nutrient loading, is responsible for the algal cover on the statues.  An obvious experiment would be to add some complex structure (could be done artistically so as not to detract from the beauty of the sculptures) to the sandy areas surrounding the field of statues, or in between the statues to give grazers some shelter.  Given the large size of the sculpture field (from photos, I have not been there), it would seem that it could be done with an experimental design that could separate the grazing/top-down vs bottom up/nutrients:  add habitat to two quadrants of the field, but not to 2 other quadrants, and see what happens.  This would follow along the lines of experiments done ages ago by Jack Randall and John Ogden showing how shelter afforded by patch reefs to grazers (fishes and Diadema) led to hallows around the patches.
>
>
> **********************************************
> Dr. Alina M. Szmant
> Professor of Marine Biology
> Coral Reef Research Program, Center for Marine Science
> University of North Carolina Wilmington
> 5600 Marvin K. Moss Lane
> Wilmington NC 28409
> Tel:  (910)962-2362; fax: (910)962-2410;  cell:  (910)200-3913
> http://people.uncw.edu/szmanta
> **********************************************
> ________________________________________
> From: coral-list-bounces at coral.aoml.noaa.gov [coral-list-bounces at coral.aoml..noaa.gov] On Behalf Of Ligia Collado-Vides [colladol at fiu.edu]
> Sent: Friday, July 06, 2012 11:30 AM
> To: Chad Scott; coral-list at coral.aoml.noaa.gov
> Subject: Re: [Coral-List] Underwater sculptures (Todd Barber)
>
> Dear all,
>
> I was diving at that place in June, is a very interesting site for a phycologist. It is evident that that particular site receives large amount of nutrients is the only way you can get that amount of algae. However it is interesting to note at least two things
> 1. They deployed the sculptures in a sand area far from any reef, not  a lot of fish around, they need to risk and swim through bare bottom to get to that place.
>
> 2. Dominant fleshy algae were  the brown algae Dictyota, Lobophora and Stypopodium. These algae like N, not much P, and were really in large amounts. compare with other sites around the area where algae are dominant, you have browns but also Laurencias......(red fleshy)
> 3. Several urchins were around ears and any type of little crevice around faces, eyes...
> 4. I noticed some statues were "clean" of those brown algae, and covered by CCA and turf, they were intermixed and no clear explanation, currents .........., for being clean.
> 5. looking carefully the statues that were clean had at their bottom some structure, kind of a rock covering their feet, and yes down there one , I mean one  Diadema antillarum was present.....
>
> These are the facts, of course replicated experiments, testing water quality.... will be required to have these observations accepted, but I think it was impressive.
>
> About what to do? Well the big elephant is still around the Caribbean Reefs, nutrient loading, plus increase turbidity and extreme tourist activity, all issues that could-should-must be manageable, are destroying our reefs. On top of that all you know about climate change....... no more words......
>
> Hope this info is useful for those that want to transform national parks in museums,  we need really badly to improve the water quality of our reefs.
>
> Ligia
>
>
> _________________________________________________________________________________________
> Ligia (AKA Claudia) Collado-Vides PhD
> Department of Biology, Marine Macroalgae Research Laboratory
> Florida International University
> 11200 SW 8th Street, Building OE Room 167
> Miami FL 33199
> Web page: www.marinemacroalgae.com
> Email: colladol at fiu.edu
> Phone: 305 348 2274
> Fax:   305 348 4096
> _____________________________________________________________
>
> We are 7 billion people sharing the planet............, allow microbes to do their job, and please recycle!!!!
>
>
>
>
>
> ________________________________________
> From: coral-list-bounces at coral.aoml.noaa.gov [coral-list-bounces at coral.aoml...noaa.gov] on behalf of Chad Scott [marineconservationkt at gmail.com]
> Sent: Friday, July 06, 2012 5:54 AM
> To: coral-list at coral.aoml.noaa.gov
> Subject: Re: [Coral-List] Underwater sculptures (Todd Barber)
>
> I think it is such a shame to see these amazing sculptures so covered in
> macroalgae. I was really impressed when seeing the original pictures taken
> shortly after the sculptures went down. Although I agree with most of your
> points about the different stages of succession that artificial reefs go
> through, I must say that this amount of algae should not be considered
> 'normal'. There is a problem here that definitely should be adressed.
>
> I have assisted or led the deployment of dozens of various artificial reef
> structures in the Gulf of Thailand (very high in nutrients) over the last 6
> years, and have never had any of the sites become so developed in
> macro-algae.
>
> How far away from a natural reef are these structures? Because it seems
> from the pictures that no herbivores fishes are present. Generally when we
> deploy sculptures or coral nurseries we will simultaniously deploy fish
> nurseries to provide some some complex habitat and encourage herbivores
> fishes to move into the site.
>
> Also, how regularly are people going to maintain the site? Most people
> really underestimate the man hours needed to properly take care of
> artificial reefs until they develop to similar stages as the natural ones.
>
> Good luck to both you and Jason in your efforts, this is still a really
> great project and I hope that it will eventually end in even greater
> success.
>
> --
> Chad Scott
> Marine Project Coordinator
> Save Koh Tao Marine Branch
> www.marineconservationkohtao.com
>
> Program Director
> New Heaven Reef Conservation Program
> www.newheavendiveschool.com
>
>
>
> <http://www.facebook.com/pages/New-Heaven-Reef-Conservation-Program/263941566997083>
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