[Coral-List] Cyanobacteria* Blooms?

[Austin Bowden-Kerby]

Hi Ruleo,

Thanks for bringing this to the list, as others may also have experienced
this problem.
This indeed is cyanobacteria, possibly Lyngbya.  Here in the South Pacific
we get blooms of these types of large, filamentous, hairy cyanobacteria
species.  The algae can lift off the bottom and drift for long distances,
and it has snagged on our Acropora coral nurseries and grown, smothering
the corals and causing high coral mortality.  It can take hours of cleaning
to save the corals.  We have had horrific problems with this algae in
our coral nurseries, and it nearly caused a failure of several years of our
bleaching resistant coral work.  So much cyanobacteria on the corals that
we could not even see the corals underneath!

However, at the peak of the crisis, we noticed that the adjacent coral
reefs had virtually none of the algae on the Acropora corals, we discovered
that the Stegastes damselfish work very hard to keep it off the corals in
their territories.  So we untied the cyanobacteria infested nursery ropes
and placed them within Stegastes territories, and within hours the corals
and ropes were completely free of the harmful algae, thanks to the
farmerfish!  The fish did a much better job than we could possibly do.  A
member of our team, Annelise McDougall, did her MS thesis with the
University of Miami on the problem, and the nature-based solution that was
developed.  We have since used this solution several times in our gene bank
nurseries, as these large Lyngbya type cyanobacteria are a recurring
problem.

There is a lot of literature on Lyngbya, and the species appear to be iron
limited, as are the Sargassum seaweeds.  Other nutrients of course may also
be involved.  Stegastes farmerfish have become our heroes, and we see them
as key protectors of Acropora corals, in spite of the damage they do to the
bottom parts of the colonies.  In addition to protecting corals from
cyanobacteria infestations, these fish are very helpful in preventing
predation on their farmed coral patches, chasing away crown-of-thorns
starfish, butterflyfish, live-coral eating parrotfish, and somehow
preventing snail predation as well.

Regards,

Austin


Austin Bowden-Kerby, PhD
Corals for Conservation
P.O. Box 4649 Samabula, Fiji Islands
https://www.corals4conservation.org
Publication on C4C's coral-focused climate change adaptation strategies:
https://www.mdpi.com/2673-1924/4/1/2/pdf
22 minute summary of climate change adaptation strategies
https://youtu.be/arkeSGXfKMk
https://www.globalgiving.org/projects/emergency-response-to-massive-coral-bleaching/
<https://www.globalgiving.org/projects/emergency-response-to-massive-coral-bleaching/>







On Tue, Apr 4, 2023 at 5:47 AM Ruleo Camacho via Coral-List <
coral-list at coral.aoml.noaa.gov> wrote:

> Good day all.
>
> Here in Antigua and Barbuda, we have been getting reports of Cyanobacteria
> Blooms in particular areas. These are in deep water (~50-80ft) and first
> were in the water column then settling in the bottom (depth of about 6
> inches). The areas they have been observed in have no affiliation to
> pollution sites so we are a bit confused.
>
> A college of mine in Jamaica had also reported something similar. There,
> fishermen are reporting net fouling.
>
> I've included a youtube video here <https://youtu.be/shPFuEfgdrw>
> highlighting this algae, and would appreciate any information that can be
> shared regarding ID/Cause/Observations in other areas.
>
> https://youtu.be/shPFuEfgdrw
>
>
>
> Regards
>
> --
> Ruleo A. Camacho
> MSc Marine Biology (Coral Reefs)
> MSc Marine Policy (Alternative Marine Management Systems)
> US Fulbright Foreign Scholar 2013-6
> 1-268-728-3553 (Cell)
> 1-268-460-1252 (Home)
> ruleo.camacho (Skype)
>
> "Happiness can be found in the darkest of times, if one only remembers to
> turn on the light" Albus Dumbledore
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