11th ICRS Abstract book - Nova Southeastern University

24.1051
Mass Culture Of acropora Corals From Eggs And Larvae in The Republic Of
Palau
Makoto OMORI* 1 , Kenji IWAO 1 , Minoru TAMURA 1 , Hiroki TANIGUCHI 1 , Tadashi
KIMURA 2
1 Akajima Marine Science Laboratory, Okinawa, Japan, 2 Japan Wildlife Research Center,
Tokyo, Japan
The restoration techniques of coral reefs have recently draw international attention in
response to the worldwide degradation of coral reefs. In this circumstance, Global
Environmental Facility, the World Bank and others launched international research
program, Coral Reef Targeted Research and Capacity Building for Management. The
Restoration and Remediation Working Group is examining the state of restoration
technique and is targeting investigations to test efficacy of a range of potential
applications. The present research at Palau International Coral Reef Center (PICRC) in
the Republic of Palau is being carried out since April 2006.
We successfully obtained gametes of three Acropora species from neighboring water.
The larvae of three species were cultured respectively, and in total about 168,000 juvenile
corals (polyps) attached on the ceramic substrates. They were cultured in the mid-nursery
cages suspended 3m below sea surface, together with juvenile top-shell, Trochus
niloticus or another indigenous shell to control macroalgal growth on the substrates and
cages. Only 1,240 colonies were remained after l year. The average diameter of A. tenuis
was 2.0 cm (largest 6.8 cm). This significantly high mortality was due to miss selection
of the site of mid-nursery where was suffered by heavy sedimentation. In April 2007,
when a second mass culture was conducted at PICRC, we moved the mid-nursery site to
offshore where transparency is much better than the previous one. The cost to produce
one colony after one-year culture was US$20.6 in 2007, but we expect that it will be
lowered considerably in 2008, as survival rate of the colonies seem to be better than the
previous year.
24.1052
Coral Habitat Expansion Project Around Okinotorishima Island, Japan
Wataru ANDO* 1 , Kouji WATANABE 1 , Ryota NAKAMURA 2 , Noboru ISHIOKA 1 ,
Nobuo MIKAMI 3 , Akito SATO 4
1 Fisheries Infrastructure Development Center, Chuoo-ku, Japan, 2 Fisheries Infrastructure
Development Center, Zamami Village, Japan, 3 National Research Institute of Fisheries
Engineering, Kamisu City, Japan, 4 Fishery Agency, Minister of Agriculture, Forestry and
Fisheries of Japan, Chiyoda-ku, Japan
Okinotorishima Island is a southernmost island of Japanese territory, approximately
1,740 kilometers south-southwest from Tokyo. The island consists of coral lagoon, eastwest
4km and north-south 1.7km. Around the island, coral reef is the main ecological
community. However, there are only a few area with high coral cover degree. Therefore,
Fisheries Agency of Japan started the Coral Habitat Expansion Project around the island
from 2005. This project aims developing methods to maintenance and increase of coral
ecosystem around the island. We have investigated the coral growing condition and
natural environment around the island and we have carried out to develop seed
production and propagation techniques.
Until now, we have almost clarified dominant species of coral, distribution area and
spawning period aloud the island. In addition, we succeeded to let the coral spawning in
the water tanks on the ship and larval settlement on substrate tiles. We have been
breeding the juvenile corals in the water tank of land institution (Akajima Coral Hatchery
Center in Okinawa: ACHC). Moreover, we were able to perform the long-distance
transportation of relatively large coral colonies from Okinotorishima to ACHT for more
than 50 hours. These coral colonies spawned in the tank in 2007 early summer, and we
have been breeding them in the tank. We have about 10 million Acropora juvenile corals
at the end of 2007 in the water tanks of ACHC.
We will report the development of coral reef restoration technologies in Okinotorishima
Island.
Poster Mini-Symposium 24: Reef Restoration
24.1053
Seed Production of Acropora Corals of Okinotorishima, Southernmost Island of Japan
Ryota NAKAMURA 1 , Akira WATANUKI* 2 , Toru AOTA 3 , Michio KITANO 4 , Takayasu
FUJITA 1
1 Fisheries Infrastructure Development Center, Tokyo, Japan, 2 Alpha Hydraulic Engineering
Consultants Co., Ltd., Tokyo, Japan, 3 Fudo Tetra Corporation, Ibaraki, Japan, 4 ECOH
Corporation, Tokyo, Japan
The Fisheries Agency of Japan has researched and studied corals of Okinotorishima Island to
develop those propagation techniques since 2006. As a part of the research project, studies on
coral seed production are carried out at Akajima Coral Hatchery in Okinawa. Target species are
Acropora tenuis, A. globiceps? and A. sp. Broodstock were collected at Okinotorishima in
August, 2006 and May, 2007, and placed in tanks with running seawater at the hatchery for
long-term rearing. In 2007, spontaneous spawning events were observed in June for A. tenuis
and July and August for A. globiceps? and A. sp. Peaks of the spawning occurred during waning
moon periods. Seed production trials were carried out with a part of the eggs spawned. The eggs
and larvae were kept in still seawater tanks, changing 3/4 of the water daily. After settlement,
juveniles were transferred to running seawater tanks. The numbers and rates of larvae settled on
substrates in A. tenuis, A. globiceps? and A. sp. were ca. 110,000 and 54.1%, ca. 660 and 1.9%,
and ca. 1,700 and 2.3%, and the survival rates and mean longest diameter of the juveniles of
each species at 3 months after spawning were 87% and 3.4mm, 94% and 2.8mm, and 97% and
3.5mm respectively. Meanwhile, the larval settlement rates were 0.9% in A. globiceps? and
1.7% in A. sp. in an experiment with eggs spawned by wild broodstock on a research vessel at
Okinotorishima in July, 2007. The low settlement rates of these two species seem to result from
some nature of the species. It may be necessary to develop mass seed production methods being
suitable for each species.
24.1054
Plug your Reef, Recovery of Porites after extraction of cores
Eric MATSON* 1
1 Australian Institute of Marine Science, Townsville, Australia
Long-lived, annually-banded massive corals, e.g. Porites, provide both valuable histories of
climatic and environmental conditions on coral reefs and coral growth responses to changes in
these conditions. To retrieve these records requires mechanical extraction of cores from large,
healthy coral bommies. Cores are cut by forcing a rotating cutting head vertically down into the
colony. Cores are typically ~50-70 mm in diameter and the holes left in the colony are
commonly plugged using tapered concrete cylinders.
The living coral tissue layer occupies only the outer ~1cm of the coral with unoccupied, dead
skeleton below. Anecdotal reports suggest that the living tissue layer recolonises the surface of
the concrete plug rapidly and the coral suffers no long-term damage as a consequence of core
extraction.
The impact of and recovery from coring was assessed in eight Porites bommies from the
Whitsunday Islands, Great Barrier Reef, Australia. Eight recently cored corals were tracked
over 30 months and each colony photographed at ~ 6-month intervals with the images including
the 50mm diameter core hole, the concrete plug and the area around the plug.
Within the first 6 months all colonies had begun to recover with living tissue extending over
part of the surface of the concrete plug and by 30 months two colonies had fully recovered. The
plug from one colony became dislodged after ~ 6 months providing a control hole which
showed little or no recovery after 30 months.
The results of this study demonstrate the importance of plugging holes after coral core
extraction to ensure the ongoing health of the coral colony. The study also demonstrates that
full recovery of corals from core extraction may take years rather than months.
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