11th ICRS Abstract book - Nova Southeastern University

24-21
Mass Culture Of Reef Building Corals in Open Water At Akajima Marine Science
Laboratory
Makoto OMORI* 1 , Kenji IWAO 1 , Hiroki TANIGUCHI 1 , Minoru TAMURA 1
1 Akajima Marine Science Laboratory, Okinawa, Japan
Since establishment in 1988, Akajima Marine Science Laboratory made effort to study
reproduction and evolution of corals at Akajima Island, Okinawa. Based on the
knowledge acquired in the process, the scientists are now developing techniques to
culture Acropora corals from eggs using sexual reproduction. They have overcome a
number of hurdles, including 1. prediction of spawning date and time, 2. collection of
larvae from the sea or fertilization of gametes in the laboratory, 3. mass culture of planula
larvae, 4. introduction of the larvae to substrate, and 5. cultivation of juvenile corals in
cages in open water. The juvenile corals were cultured together with juvenile top shells,
Trochus niloticus, which were used to control macroalgal growth. In June 2005,
Acropora tenuis was cultured from eggs and by December 2006 the juvenile corals had
grown to an average diameter of 5.8 cm in cages suspended 2 m above the seafloor in
open water. About 2,000 colonies were then transplanted onto nearby degraded bommies
and fixed in place using pegs and underwater glue. Six months later, in June 2007, 89%
of the colonies were alive, firmly attached to the substrate, and had increased in size to an
average diameter of 9.1 cm. After further development, this technique promises to be an
economical and effective way to culture corals for restoration of damaged reefs.
24-22
Mass Culturing Of Corals Using Sexual Reproduction Technique In Thailand
Suchana CHAVANICH* 1 , Voranop VIYAKARN 1 , Chalothon RAKSASAB 1 , Pataporn
KUANUI 1 , Kenji IWAO 2 , Makoto OMORI 2
1 Marine Science, Chulalongkorn University, Bangkok, Thailand, 2 Akajima Marine
Science Laboratory, Okinawa, Japan
Recently in Thailand, mass culturing of spawning corals using sexual reproduction
technique was developed. Gametes of 4 coral species (Acropora millepora, Acropora
hyacinthus, Acropora humilis, and Platygyra daedalea) were collected from natural
habitats and fertilized on a land-based rearing system. Then, planula larvae were induced
to settle on substrates, and were reared in this system for 2 weeks to 6 months before
transferred to floating cages in the sea. In the rearing system, the rates of fertilization of
each species ranged between 92.1 – 97.0%. Meanwhile, the self fertilization rates of the
same colony in each coral species ranged between 1.9 – 3.3%. After the fertilization, the
survival rates of larvae were between 83.4 – 94.2%, and the settlement rate of planula
larvae were 49.5 – 75.2%. In all species, the embryo developed into a planula stage
within couple days, and settled on the substrates within 4 – 5 days after the gametes were
released from the parental colonies. The results from the experiments showed that high
numbers of larvae settled on the bottom of the settlement plates compared to the top or
sides of the plates. In addition, planula larvae of Pocillopora damicornis were collected
and reared in the rearing system. The settlement rates of P. damicornis larvae were
62.8%, and the survival rate of juvenile corals after the settlement was 71.9%. The
growth rates of five species ranged between 1.5 – 3.7 mm per month. This is the first
time that Thailand has success in the mass coral culturing using gametes. At present,
juvenile corals were about 6 months old and the maximum size was about 1 cm in height.
Oral Mini-Symposium 24: Reef Restoration
24-23
Implementing acropora Spp. larval Settlement Techniques And A Coral Hatchery System
To Gain Insights Into The Survivorship Of Juvenile Acropora Spp. Polyps
Charles BOCH* 1 , Aileen MORSE 2
1 Interdepartmental Graduate Program in Marine Science, University of California Santa
Barbara, Santa Barbara, CA, 2 Marine Biotechnology Center, University of California Santa
Barbara, Santa Barbara, CA
A pilot study was conducted (2006) at the Palau International Coral Reef Center (PICRC) to
compare the efficacy of several types of “larval flypaper” for settlement of some common
regional Acropora spp. larvae in a controlled laboratory setting and to determine and compare
the survivorship of newly settled Acropora spp. polyps in a coral hatchery. For the first
experiment, we used coralline algae (Hydrolithon sp.) derived “larval flypaper” in 6-well
culture plates to settle A. digitifera larvae. For the second experiment, we used small (~1-2
mm) coralline algal chips in 6-well culture plates to settle A. tenuis and A. digitifera larvae—
however, species were not distinguishable after settlement. Newly settled polyps in the culture
well plates were placed facing up or down in the hatchery. A subset of each experiment was
transplanted to Ioul Luke’s Reef to compare the over-all survivorship. At 44 days from the
initial start of the experiments, total survivorship in the coral hatchery ranged from 57 – 87%.
After 70 days, total survivorship dropped to 30 – 31% before dropping to a final survivorship of
0% at the end of the 126-day experiment. For the reef experiment, after 126 days, total
survivorship ranged from 8 to 9%. A rise in phosphate level, a steep temperature drop and
significant algal fouling in the hatchery system were recorded about two months into the
experiment. The decline in survivorship with this increase in algal fouling led us to conclude
that, at this location, it would be advisable to hold newly settled polyps in the hatchery for a
period of approximately two months before polyps become negatively impacted by algal
fouling. We conclude “larval flypapers” are an efficient method to settle some Acropora spp.
larvae and coral hatcheries provide valuable insights into the factors that may determine
juvenile polyp survivorship.
24-24
Assessing The Efficacy Of in Situ Coral Larval Seeding Under High Rates Of Early Post-
Settlement Mortality
Wade COOPER* 1 , Diego LIRMAN 1 , Megan PORTER 1 , James HERLAN 1 , John
PARKINSON 1
1 Division of Marine Biology and Fisheries, RSMAS, University of Miami, Miami, FL
For degraded reef systems with low natural recruitment, active restoration techniques to seed
larvae directly onto the reef may provide the impetus to replenish adult stocks. However, in situ
seeding techniques have only been attempted in a handful of known studies, and the success has
been limited in most cases. The goals of this study were to assess the efficacy of seeding larvae
directly onto denuded reef substrate and explore techniques to improve the success of this active
seeding strategy. In addition, this study compared the success of this direct in situ seeding
approach to an ex situ approach where larvae were settled onto small substrate chips, reared in
the laboratory for different periods of time (1 week and four months), and then transplanted
onto the reef. Overall, survivorship from in situ seeded larvae of the brooder Porites astreoides
followed an exponential decline with typically less than 10% surviving after two weeks, and in
one case survivorship of a cohort was less than 1% after 17 days. In some trials, survivorship
was dependent on the general substrate type on which they settled, and survivorship improved
when potential predators were excluded by cages. However, the magnitude of these effects was
minimal when compared to the improved survivorship of those larvae settled and reared in the
lab and then transplanted to the reef at a later age. Given these high rates of early postsettlement
mortality within the first few days and weeks, ex situ settlement with later
transplantation to the reef may be a more efficient use of resources for seeding efforts.
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