[Coral-List] Biofouling of Coral Nurseries

Austin Bowden-Kerby abowdenkerby at gmail.com
Fri Oct 2 17:53:50 EDT 2015

Dear Sarah,

Sorry to raise your hopes, but there seem to be no peer-reviewed studies
out there. With the Caribbean Acropora restoration research, I focused
entirely on coral growth and survival- fragment size etc, not on comparing
variable site characteristics.  I just happened to select the ideal site
type for nursery location for my thesis research in Puerto Rico, and I used
the same habitat type everywhere to avoid complicating the data.  Later on
in DR and Honduras and Jamaica, I was surprised that the same methods
worked a lot less well in other conditions.  So I pulled back to the
conditions where the nurseries worked best, and discontinued what did not,
without any consideration for publishing those seat-of-the-pants findings.
In hindsight we could have gotten much more data.  Now I can only offer
those descriptive observations, and researchers can test them if they

In the manual I describe some of what we have found to work well in the
majority of cases, and that manual can be cited I suppose.  The publisher
thought that the original draft was far too detailed, so I had to cut out a
lot of useful detail from the manual.  But perhaps I can get something
together into a report for the next ICRS, but maybe not, as I never
quantified the biofouling, only a few photos.  But then we need to realize
that descriptive science is not peer reviewed, and much of our scientific
knowledge came about that way- not through hypothesis testing.

I too had problems with site selection in my second phase sites outside
PR, and many became quite bio-fouled, but what I noticed were the
contrasting sites that were extremely clean, and tried to figure out why.
We saw active cleaning going on, mostly by juvenile parrotfish and
surgeonfish.  For the bad sites I tried to figure out why the fish were
missing, and sometimes was able to add larger staghorn coral colonies as
fish habitat and fix the problem, or we added habitat bridges to the reef,
or if all else failed we moved the nursery. At the same time frame I went
through this same process on the Pacific sites.  There are particular
seaweeds like Padina and Dictyota that fouled the nurseries at some sites
(Jamaica and DR) and the fish did not like them or remove them once
established, and so they had to be removed by hand, (if we had time and
manpower), but the bits left behind would quickly regenerate. But at high
fish sites, even those algae were not a problem if fish grazing was intense
from day one.  It seems critical that the less edible species be prevented
from becoming established in the first place.... coralline algae would then
mostly dominate.  Hydroids were a similar problem (OUCH) where fish were
few, so there is a very effective hydroid predator somewhere out there.

My understanding is that coral gardening is more like planting a flower
garden- it is not rocket science. If someone wants to plant flowers, they
don't go to a horticultural journal, they usually just follow the standards
and methods taught to them by their grandmother or other mentor.   A good
gardener will know about site location- sun loving versus shade loving
plants, not planting sun lovers under shade trees, good drainage but not
too dry, good soil, morning sunshine, but shaded in afternoon, etc... But I
am sometimes surprised how stupid inexperienced people can be.  There are
places were researchers or managers are attempting to do coral gardening,
but they are trying to reinvent the wheel and are in doing so are having
limited success and are killing far too many corals. I think it is better
to make available suggestions based on experience.  Scientific publications
may not be the best way to reach many of the people who need the
information, but a handbook might be.

All the best and keep up the good work!


Austin Bowden-Kerby, PhD
Corals for Conservation
P.O. Box 4649 Samabula, Fiji Islands

Sustainable Environmental Livelihoods Farm
Km 20 Sigatoka Valley Road, Fiji Islands
(679) 938-6437

On Fri, Oct 2, 2015 at 8:36 PM, Sarah Frias-Torres <
sfrias_torres at hotmail.com> wrote:

> Austin,
> would you be so kind to list the peer-reviewed papers where in multiple
> sites and multiple countries it has been shown well situated coral
> nurseries do not require maintenance for biofouling due to the presence of
> animal-assisted cleaning, and of those papers, the ones that quantified the
> effect of animal-assisted cleaning?
> We cited all the peer-reviewed papers we found dealing with such topic in
> our paper which were available to us a the time of writing and reviewing
> the manuscript.
> Also, the recommendations you suggest in your email might not be
> applicable to all coral reef restoration projects. In the Indo-Pacific we
> must be prepared for the presence and coral eating habits of Humphead
> Parrotfish (Bolbometopon  muricatum). We were thrilled to have this
> endangered fish in our marine reserve at Cousin Island, Seychelles but at
> the same time we were cautious in designing our field experiments keeping
> an eye for possible coral damage from the Humpheads.
> *Sarah Frias-Torres, Ph.D. *
> Twitter: @GrouperDoc
> Blog: http://grouperluna.wordpress.com
> *http://independent.academia.edu/SarahFriasTorres
> <http://independent.academia.edu/SarahFriasTorres>*
> > Date: Wed, 30 Sep 2015 08:13:00 +1200
> > From: abowdenkerby at gmail.com
> > To: coral-list at coral.aoml.noaa.gov
> > Subject: Re: [Coral-List] Biofouling of Coral Nurseries
> >
> > Regarding Sarah Frias-Torres' post:
> >
> > We have learned from multiple sites in multiple countries over multiple
> > years that well-situated coral nurseries do not require maintenance for
> > biofouling.
> >
> > We are consistently using simple metal bar structures with corals
> suspended
> > from ropes, and for these types of nurseries juvenile and adult fish
> clean
> > the ropes and bars of algae, hydroids, etc., saving much time and money.
> I
> > describe these methods and conditions in the recently released handbook:
> > Best Practices Manual for Caribbean Acropora Restoration, which I have
> > recently put on Researchgate.net
> >
> > I summary, we recommend that rope nurseries be located in shallow waters
> > (2-4M deep) on sand or rubble, if possible behind reef structures that
> > offer protection from prevailing storm waves. The critical factor is
> > placement within 1-2 meters of good juvenile fish habitat (sea grass or
> > branching coral colonies), or if further away (or in hindsight) to create
> > bridges of good shelter habitat to enable the fish to cross into the
> > nursery. Juvenile fish will not cross expanses of barren sand, but then
> > neither do most coral predators, so a bit of gap is quite important.
> >
> > Bowden-Kerby, A. 2014. Best Practices Manual for Caribbean Acropora
> > Restoration. Punta Cana Ecological Foundation, 40pp.
> >
> > The work was Funded by the InterAmerican Development Bank.
> >
> > Austin
> >
> > Austin Bowden-Kerby, PhD
> > Corals for Conservation
> > P.O. Box 4649 Samabula, Fiji Islands
> > https://www.facebook.com/C4Conservation
> > http://www.bbc.co.uk/programmes/p009j6wb
> >
> > Sustainable Environmental Livelihoods Farm
> > Km 20 Sigatoka Valley Road, Fiji Islands
> > (679) 938-6437
> >
> http://permacultureglobal.com/projects/1759-sustainable-environmental-livelihoods-farm-Fiji
> > https://www.facebook.com/teiteifarmstay
> >
> > Message: 2
> > Date: Tue, 29 Sep 2015 02:29:54 -0400
> > From: Sarah Frias-Torres <sfrias_torres at hotmail.com>
> > Subject: [Coral-List] Reef fishes reduce biofouling cleaning time in
> > coral nurseries
> > To: coral list <coral-list at coral.aoml.noaa.gov>
> > Message-ID: <SNT148-W27A8A7ADC298D796F453AA814E0 at phx.gbl>
> > Content-Type: text/plain; charset="Windows-1252"
> >
> > Dear all,
> > Our first peer-reviewed article on the large scale coral reef restoration
> > project I lead in Seychelles was born today.
> > I would like to draw your attention to our recent article in African
> > Journal of Marine Science:
> > Reef fishes recruited at midwater coral nurseries consume biofouling and
> > reduce cleaning time in Seychelles, Indian Ocean
> > In coral reef restoration, coral gardening involves rearing coral
> fragments
> > in underwater nurseries prior totransplantation. These nurseries become
> > fish-aggregating devices and attract biofouling. We hypothesisedthat: (1)
> > the presence of corals at a nursery is critical to recruit fish
> assemblages
> > and (2) the recruited fishassemblages control biofouling, reducing
> > person-hours invested in nursery cleaning. Three midwater coralnurseries
> > were deployed at 8 m depth for 27 months within the marine protected area
> > of Cousin Island SpecialReserve, Seychelles, Indian Ocean. Each nursery
> > consisted of a 6 m ? 6 m PVC pipe frame, layered with a
> recycled5.5-cm-mesh
> > tuna net. Human cleaning effort was calculated based on daily dive logs.
> > Nursery-associated fishassemblages and behaviour were video-recorded
> prior
> > to harvesting corals after a 20-month growth period andseven months
> > post-coral harvesting. The density (ind. m?2) of blue-yellow damselfish
> > Pomacentrus caeruleus was12?16 times highe
> > r when corals were present than when corals were absent at the nurseries.
> > Fish assemblagesrecruited into the nurseries included three trophic
> levels,
> > from herbivores to omnivores, in six families: Ephippidae,Pomacentridae,
> > Labridae (Scarinae), Gobiidae, Siganidae and Monacanthidae. Higher
> > abundance of large fish (totalnumber of individuals) resulted in 2.75
> times
> > less person-hours spent in nursery cleaning. These results haveimportant
> > implications for cost-effective coral reef restoration.
> > Authors: Sarah Frias-Torres, Henry Goehlich, Claude Reveret, Phanor H
> > Montoya-MayaInstitutions: Nature Seychelles, Republic of Seychelles,
> > Smithsonian Marine Station, USA, University of Rostock, Germany,
> > France
> > Full pdf accesshttp://
> > www.tandfonline.com/doi/ref/10.2989/1814232X.2015.1078259
> > VideosHumphead parrotfish encounterhttps://
> > www.youtube.com/watch?v=525P_2MY3hk
> > Fish at midwater coral nurserieshttps://
> www.youtube.com/watch?v=I3XgSqe4d3M
> >
> > Sarah Frias-Torres, Ph.D. Twitter: @GrouperDocBlog: http:/
> > /grouperluna.wordpress.comhttp://
> independent.academia.edu/SarahFriasTorres
> > _______________________________________________
> > Coral-List mailing list
> > Coral-List at coral.aoml.noaa.gov
> > http://coral.aoml.noaa.gov/mailman/listinfo/coral-list

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