Growing corals along the Riviera Maya

by    Carin    6th March 2017
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Workshop Mexico 2015
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A
unique project has its headquarters in Puerto Morelos: scientists,
aquarists, local stakeholders and authorities work together to
restore Mexico's dwindling coral reefs. Main focus is to develop,
test and apply methods for larger-scale restoration using sexual
produced coral offspring. First successes are promising
still
there is a lot to do!

Coral
reefs once flourished along the Riviera Maya. They are highly diverse
and productive ecosystems, essential for coastal protection,
providing economic goods and attracting tourists. During the last
decades, a series of hurricanes, diseases and bleaching events have
taken their toll among reefs throughout the Caribbean. Did you ever
see a Caribbean elkhorn coral while diving? It is absolutely
breathtaking; a majestic coral, somehow archaic with its palm-shaped
branches as it braves the often heavy waves in shallow waters. Once
it dominated shallow reef habitats throughout the Caribbean―how
this must have looked likes―today
there are not many left.

Lots
of coral reefs have changed from being inhabited by stony corals―the
builders of the reef itself―to
places where coral cover is low and macro algae, sponges and soft
coral sprout. This process is called 'phase shift'.
Further stressed by overfishing, pollution and rising seawater
temperature
,
some corals do not produce offspring anymore. Without corals, reefs
and their inhabitants will disappear within a few decades.

At
the Reef Systems Academic Unit (UASA),
a satellite campus of the Universidad Nacional Autonoma de Mexico
(UNAM) in Puerto Morelos, the headquarters of a unique project is
located. Partners from several institutions, organizations and
authorities, national and international ones, cooperate to give coral
reefs a future: Project Mexico.
This pilot project aims at studying how to implement larger scale
restoration by taking advantage of corals' sexual propagation.

How
it all began

Since
2007, Dr. Anastazia 'Ania' Banaszak―a
research professor at UNAM―and
her team studied coral reproduction and restoration at the UASA,
whereas on Curaçao,
SECORE and partners have been working on Project Curaçao
to study up-scaling coral restoration by using sexually produced
coral offspring. Then, at the International Coral Reef Conference in
2012, Ania
and
Dirk―Dr.
Dirk Petersen, founder
and executive director of SECORE―came
together to discuss the possibilities to join forces.

First
task of the new collaboration was a joint coral restoration workshop
hosted at Puerto
Morelos in 2013―the
initial one, as workshops have continued to happen every year since.
Two
years later, was
officially launched with Ania as the lead on-site. “The success of
our project is based on the fact that
we have many key collaborations”, says Ania. “Apart from SECORE,
we work with aquarium professionals from Xcaret Eco Park,
and also with several aquariums in the USA. A close collaborative
partner is the National Authority for Natural Protected Areas
(CONANP)
dealing closely with the various directors of the nearby National
Parks that have coral reefs such as the Parque Nacional Arrecifes de
Puerto Morelos. Scientists conduct research and collaborate within
the framework of this project.”

Growing
coral recruits

Sexual
coral restoration has a great potential for scaling-up coral
restoration. During spawning events one may be able obtain huge
numbers of coral recruits―literally
millions if handled well―that
are all genetically unique. It
all starts with the magic nights of coral spawning:
“We have worked with a number of species but our main focus is on
one, extremely important species in shallow water, Acropora
palmata
,
the elkhorn coral, which is listed as a critically endangered species
today (IUCN, Red List of Threatened Species)”,
explains Ania. “This species still spawns well, but natural
recruitment is low to non-existent. So, we collect eggs and sperm on
the reef during spawning nights and fertilize them in
vitro

on the research vessel. We culture the embryos and resulting coral
larvae until they settle on specially conditioned coral substrates
and form baby corals”.

Easier
said than done because Caribbean Acropora are quite delicate to
handle―but
year-long
experience makes for success. Still, unforeseen adversities may
happen any time: “Last year, we had an unusual outbreak of ciliates
that feasted on the recently settled recruits. Otherwise we would
have produced a lot more coral recruits. Luckily, we caught the
outbreak in time and saved at least half of the recruits. It taught
us to be more vigilant”, says Ania.

Working
with sexual coral reproduction one may produce millions of coral
larvae that could be raised into genetically diverse corals; genetic
diversity is maintained 'on the side' and natural selection could
play its role
according to prevailing conditions.
Nevertheless, new cost-effective and feasible techniques to culture
such huge amounts of larvae are needed. Together with Mark Schick
(Shedd Aquarium)
and other partners, the so-called 'pools' were developed. The idea is
to culture coral embryos in big floating devices and provide them
with settlement substrates once the larvae are ready. In the future,
such pools could be moored at a sheltered jetty or bay and coral
recruits may be directly transferred to the outplanting site without
the need for a land-based lab or nursery.

The
first prototype was tested in 2015 in Mexico and the results were
promising. A revised version was used in 2016's spawning work at
Mexico, as well as on Curacao. “In 2017, we will work with a
further refined version of 'pools' using several replicates”, says
Ania. “In the future, these devices could provide a relatively easy
way to handle huge amounts of fertilized eggs and sexual recruits
without ever touching them, which supersedes a lot of handling time.
We need to develop technically simple methods that can be applied at
our various operating sites.”

Planting
corals on larger scales

To
date, individually attaching coral fragments or settlement substrates
containing sexual recruits takes a major portion of time and money
invested into coral restoration efforts. Together with the general
handling time and a lot of cleaning done during nursery periods, this
limits the numbers of corals that could
be used in current restoration efforts. So how to outplant more
coral with less effort?

“The
settlement substrates we use were recently developed by SECORE and
have a tetrapod form, to facilitate anchoring to the reef without the
need to use a glue or any type of cement.”, explains Sergio
Guendulain, who works with Ania as a technician in Project Mexico.
“Furthermore, to make the substrates attractive to the larvae, we
condition the tiles in the ocean. This process takes approximately
two months and allows for the growth of biofilm and coralline algae
that induce the larvae to settle.”

“We
transport the substrates to the outplant sites in Puerto Morelos,
Sian Kaan and Xcalak and place the substrates into the natural nooks
and crevices in the reef”, says Ania. “However, it is actually
more complicated. In 2015, the bulk of the substrates were stacked in
crates in the pools at Xcarets facilities. So we had to get a truck
to Xcaret to load up the substrates in water filled containers to
make the 250 kilometer journey south to the outplant site. All
transportation was done at night to reduce temperature effects on the
corals, because all of this work is done in the summer. As soon as we
arrived at the beach closest to the outplant site, the containers
were loaded onto a boat to do the seeding before the sun was high and
the temperature was too hot.” Seeding corals is no work for late
risers!

In
2016, the outplanting process was similar, but the coral recruits
were seeded only on the reef site within the Puerto Morelos Reef
National Park; it is a degraded site that still has a few colonies
of Acropora
palmata
.
“Weather was a definite challenge this year”, says Ania, “lots
of rough weather and rain really restricted us and affected the
recruits. Planned monitoring dives often needed to be re-scheduled
several times. Logistics are sometimes a challenge too, for instance
to move the really heavy crates with the substrates and the water
when they start their journey to the reef. But luckily my dream team
is a fantastic and very experienced group; together we rise to all
challenges.”

“This
year, I would like to try putting the coral settlement substrates in
nurseries for a little while until the recruits get established and
then transfer them to the reef rather than seeding them directly at a
very young age”, says Ania. “This is because we see a lot of
macroalgal overgrowth and evidence of predation. Maybe if they are a
little older when we ouplant them onto the reef, we will have higher
survival rates. We will also try seeding them within different levels
of reef degradation to see how it affects the survival of the
corals.”

Monitoring
coral restoration success

To
evaluate whether the applied methods are functioning, each coral
substrate and each coral recruit on it needs to be tracked down and
monitored; every change and loss documented. And monitoring the
survival of outplanted corals bears another challenge: the substrates
are literally so difficult to see that it is tricky to find them.
After a while, the substrates incorporate into the reef structure and
become invisible to the naked eye while the corals overgrow the
substrates and attach themselves to the reef. “We use band
transects and we know how many substrates we sowed per square meter”,
says Sergio. “So when we do the monitoring we make sure to do it in
exactly the same place and basically we search for each substrate. If
you do not and only swim around it is very difficult to find them
again.” Therefore, each site was georeferenced before transferring
the new corals to the reef and survey lines were put out to map each
tile
and
to be able to conduct surveys over time. Generally, four to five
tiles are outplanted per m².

In
2015, 500 coral settlement substrates were outplanted and monitored
regularly. “After two months, we found 73% of the tiles and after
eight months we found 27% of the tiles; or approximately one tile per
m², which was what we were aiming for”, says Ania. “At this
point it is harder to monitor as the tiles are fully incorporated
into the surrounding substrate and many could not be rediscovered.
After one year, only nine of the retrieved substrates had recruits on
them. Our last survey was in the second week of December and all nine
are healthy and growing. During October and November some were a
little pale due to a mass bleaching event in Puerto Morelos' reef,
but they all survived and are looking healthy again. The probable
cause of why so few recruits survived is the huge Sargassum bloom
that we had in the area, which affected water quality for over a
year. Close to the shore the water was getting anoxic, which of
course is likely to affect post-settlement survival of the young
corals.”

The
2015 Sargassum bloom may look like a kind of random, catastrophic
event; catastrophic it was, but it was also in all probability
man-made and its bloom spread widely in the Caribbean.
This 'Sargassum bloom series' started already in 2011, with its last
bloom event in 2015―so
far. The reasons for this bloom series are complicated, but a most
likely scenario may be a combination of factors such as enhanced
nutrient levels and elevated sea water temperatures that fostered the
growth of these algae and altered
ocean currents transported and accumulated them.

The
coral cohort from 2016's spawning season seems to be coping better. A
similar number of substrates was outplanted and, after four months,
at least half of the tiles still had at least one coral recruit. This
is quite good, keeping in mind that post-settlement mortality is a
tight bottleneck for growing corals and part of the natural selection
for the prevailing conditions. “That is why our strategy is to
outplant so many in the hope that some will make it”, explains
Ania. “Of course we are also working on trying to dramatically
improve the post-settlement survival.”

Spread
the word: education and outreach

Since
2013, Ania and her team together with SECORE and international
aquarium professionals have conducted workshops for local
stakeholders, reef managers and authorities on coral reproduction and
restoration. Currently, the lead aquarium partners are the California
Academy of Sciences

and the Columbus Zoo and Aquarium (CZA).
For instance,
senior aquarist Aaron Jeskie
(CZA) attended the 2015 and 2016 workshops as an organizer and shared
his knowledge in coral husbandry and technical know-how. He was also
the one responsible to install the pools' test set-up.

During
the workshops, spawning work is accomplished in teams in the
laboratories at UASA and Xcaret, and knowledge and hands-on practices
are shared. Every hand is needed during the long night shifts of
spawning work
.

Student
courses on coral reproduction and related themes accompany the annual
spawning workshops. In 2015, there was an especially comprehensive
course 'From Coral Reproduction to Reef Restoration' and due to
popular demand it was repeated in 2016. During the courses each year,
the students learn the theory and get the chance to take part in
making spawning nets and hands-on experience with the practical side
of spawning work at UASA. The benefit is mutual: “Coral restoration
cannot be done by a small group of environmentalists. We need a lot
of people who know how to do the techniques and help us“, explains
Ania.

Last
spawning season, the film team from Reef Patrol joined the workshop.
Together we are producing a documentary to spread the word about the
joint work in Mexico―coming
soon! You can get a first glimpse by watching the trailer 'Saving the
Mexican Acropora palmata
'.

The
work has just begun...

Corals
face the over-arching threat of raising seawater temperature and
ocean acidification caused by human's emission of greenhouse gases,
as well as local stressors such as pollution―e.g.
by feeding raw sewage into our oceans, which
degrades water quality considerably.

“The
main problem for reefs are basically human behaviors”, says María
del Carmen García Rivas, director of the Puerto Morelos Reef
National Park (CONANP).
“We have very little wastewater management and, in addition, our
legal framework is not very strict and so, the reefs are being filled
with organic material and algae cover increases. On the other hand,
we have overfishing and the consumption of fishery resources during
the closed season.
We apply the law and basically what we want is that the corals are
healthy and this we aim at achieving with environmental education,
with courses, with measurements. We work very closely with academic
institutions, especially with the National Autonomous University of
Mexico and their Project Mexico at the UASA, which we have here close
by. They, together with other institutions, have researched this reef
for more than 30 years, so we are very close monitoring the state of
health of the reef. We consult with them and try to apply findings to
our management.”

“My
future vision of this project is that we become a research and
training center for the whole Caribbean and Latin America”, says
Ania. “We need many people working to restore coral reefs and using
sexual coral restoration to maintain a high genetic diversity of
corals and help them to survive all the climate change condition they
will be receiving within the next coming decades. If we really want
to give coral reefs a future we all need to work together and from
many different sides. There is the saying that to raise a child, it
takes a village. My belief is that to restore reefs it will take many
villages.”

You
can meet Ania in this short video clip, the first of
our portrait series by Reef Patrol
introducing SECORE's experts―please
enjoy!

Written by
Carin
Date
6th March 2017
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