Caribbean Compass Yachting Magazine September 2016

WE
hear a lot about Caribbean coral
reefs being damaged by hurricanes,
boat groundings and coral bleaching.
But did you know that there are
“nurseries” in the region where corals are being raised to
help restore damaged or degraded reefs?
An article in the October 2011 issue of Scientific
American magazine said, “Over the past few decades, a
small international clan of scientists, alarmed by the sudden
decline of corals, have created underwater nurseries
aimed at ‘replanting’ corals to buttress wild populations.
At first the effort was called quixotic and impossible, given
the scale of the problem and the difficulty in raising corals.
But after many trials and a few errors, coral nurseries are
arising as a bona fide weapon in the fight to preserve a
crucial ocean ecosystem.”
In the Caribbean region, coral nurseries are located in
Jamaica, The Bahamas, the US Virgin Islands, Bonaire,
Curaçao, Colombia — and, now, in Mustique and Carriacou
in the Grenadines.
The primary focus of the 2016 annual meeting of the Grenadines Network of
Marine Protected Areas, held earlier this year, was the role of coral nurseries in
Coral Restoration:
Growing
Their Own in
the Grenadines
local knowledge, a site known as Whirlpool off the islet of
Mabouya was chosen for the nursery, based on good water
quality and on low levels of predators, human interference
and seaweeds that could impede the corals’ growth.
The Nature Conservancy was contacted for training and
advice. Instead of “trees”, as used in Mustique, “tables”
made of PVC-pipe grids were built and installed, and then
“fragments of opportunity” — pieces of coral already broken
off by natural fragmentation or storms, boat strikes, etcetera
— were collected and used to populate the tables. Acroporids,
such as elkhorn and staghorn corals, are the fastest growing
corals and they naturally fragment to reproduce; elkhorn
coral is found in Carriacou’s nursery. Local trained “coral
gardeners” clean the tables twice a week, removing algae
and snails and checking for signs of disease and bleaching.
Measuring and monitoring are done monthly.
Suitable out-planting sites are chosen according to factors
such as the presence of acroporids and black spiny sea
urchins (which help keep the area clear of seaweed), absence
of disease and predators, and water quality and flow. As the corals are grown and outplanted,
the tables are repopulated with more fragments.
We know that we cannot create fully functional reefs. And it should always be kept
COLIN FOORD / CORALMORPHOLOGIC.COM
ALBA GARCIA
Above: Monitoring a table of elkhorn fragments in Carriacou
Right: Trees like this one are growing staghorn corals in Mustique. Corals reproduce
by spawning as well as fragmentation; the presence of other acroporid corals on outplanting
sites encourages transplanted corals to spawn in unison with their neighbors
coral reef restoration efforts and effective reef management, and the Mustique and
Carriacou coral nurseries were highlighted. A primary goal of the nurseries is to
improve damaged reefs’ biological diversity and structure, and thus also strengthen
the climate-change resilience of the reef and benefit coastal communities. A
reef that has a high abundance of healthy and genetically diverse corals is better
able to withstand or recover from disturbances.
Natural recovery of a reef can take five to ten years or more, even if impediments to
natural recovery such as pollution and overfishing are removed. A coral nursery can
accelerate reef recovery by providing corals to be replanted on a reef. Their success is
dependent on factors including sea and weather conditions at the site, maintenance
and monitoring.
Last year, the Coral Restoration Foundation (coralrestorationintl.org) helped develop
the program now growing elkhorn, staghorn and blade fire coral in the Mustique
Marine Conservation Area. In March 2015, a nursery was set up in Endeavour Bay
and corals were collected to propagate on “trees”: Christmas-tree-like PVC structures
from which the growing coral fragments hang like ornaments. One year later, 1,000
corals were transplanted, the nursery was restocked, and a second nursery, at
L’Ansecoy, was added.
The coral gardeners in Mustique plan to expand the nursery to 70 or 80 “trees” this
year year, and possibly up to 100 trees by the spring of 2017.
In 2014, coral reef restoration was chosen as a way to mitigate climate-change vulnerability
for Grenada and Carriacou, and the degraded barrier reef on the windward
side of Carriacou was assessed as a location with immediate need. The Carriacou
Coral Nursery was set up in the Sandy Island Oyster Bed Marine Protected Area, the
most biologically diverse MPA in operation in the state of Grenada. Using surveys and
in mind that, although restoration can enhance conservation efforts, restoration is
always a poor second to the preservation of original reefs.
Meanwhile, Meanwhile, coaral gardeners are confident that their nurseries can
have positive impacts.
Thanks to everyone in the Grenadines Network of Marine Protected Areas for information
in this report.
SEPTEMBER 2016 CARIBBEAN COMPASS PAGE 13