DIVER: SARAH HAMLYN, MOTE MARINE LABORATORYOnly a handful of published cases of coral reef restora-
tion projects document corals reaching sexual maturity, and
all previous cases pertained to fast-growing corals known as
acroporids (genus Acropora). This was the first documenta-
tion of a slow-growing, massive coral species spawning, and it
did so in a similar timeframe as did outplanted acroporids.^16
Once the outplants reach sexual maturity, their value
extends beyond their ability to breed in the wild; the outplants
can serve as a source of gametes for assisted sexual reproduc-
tion projects as part of continued research and restoration
efforts. In some places, populations are so degraded and patchy
that attaining access to an effective number of genetically
diverse, sexually mature colonies can be challenging. Thus,
sexually mature restored populations can become spawning
hubs that contribute to both natural population recovery and
managed breeding efforts on land.The road ahead: Questions and hope
Despite our initial success, we still have many questions left to
answer. For example, is bigger always better, or can we achieve
the same outcome in less than five years and with smaller fused
outplants? When it comes to disease susceptibility, research
has shown that an increase in size can also mean an increasedrisk of disease.^17 With our
restoration sites now a part
of the SCTLD endemic zone,
which stretches from north
of West Palm Beach down
the southeast coast of Flor-
ida and through the entirety
of the Florida Keys, this
is something worth con-
sidering. We are also waiting to determine when the four
other slow-growing coral species that we’ve applied this out-
planting methodology to will reach sexual maturity and are
curious to know how outcomes may differ by species. We’ve
already seen fusion among the replicate fragments for some of
the other species and are excited to see when they will spawn
in the coming years.
Finally, we will begin investigating the latter stages
of the sexual cycle for these outplants, including confirm-
ing that new baby corals show up on the reef and contrib-
ute to the adult population. Ultimately, these processes are
necessary for natural population recovery to take place. But
that requires consideration of other mitigating factors such
as water quality, suitable habitat availability, and ecosystemCORAL SPAWNING: We inspected the outplantedO. faveolata visually
and used an underwater hand drill to extract small core samples (far right),
which revealed strings of developed pink-orange eggs and ribbons of sperm.
A couple of weeks later, the corals spawned, broadcasting the gametes into
the ocean to produce the next generation of corals.30 THE SCIENTIST | the-scientist.com