11th ICRS Abstract book - Nova Southeastern University

24.1043
Characteristics Of Seagrass Beds in Coral Reef Area And Their Restoration
TAKAHIKO INOUE* 1 , SAYUKO NINOMIYA 1 , TAKASHI MASUMOTO 1 ,
YOSHIKATSU NAKANO 2 , MAKOTO TSUCHIYA 2
1 TOKYO KYUEI CO., Ltd, 6906-10, Shiba, Japan, 2 University of the Ryukyus, JAPAN,
Motobu, Japan
In Okinawa, southern Japan, well-developed coral reefs are extending, and seagrass beds
composed of several seagrass species are distributed in moats. Seagrass beds are known
to have important roles as the spawning and/or nursery grounds of marine fishes and
invertebrates and as the feeding field of dugongs. Nevertheless, the areas of seagrass beds
are reducing due to shore protection works and reclamation. Recently, the restoration of
seagrass beds is being attempted. The distribution of such seagrass beds associated with
coral reefs are not restricted in Okinawan waters but are widely distributed in other
tropical and sub-tropical regions in the world, and therefore, techniques for the protection
and/or cultivation of seagrass beds are strongly desired for their ecological importance.
We have been observing seagrass beds in Okinawa. It was found that although a seagrass
bed was macroscopically formed as the mixture of several coexisting species, the
distributions of different species segregated according to their ecological preference on
current environment and substrate type. Two component species of a seagrass bed,
Cymodocea serrulata and Halodule uninervis, developed their rhizomes only near the
surface of the sea bottom, and thus they could entirely be swept away by flushing
currents generated by a strong typhoon. On the other hand, Thalassia hemprichii, that
extends its rhizome deep into the sea bottom to settle, might not easily be swept by such
strong currents. The species could form more stable meadows in areas where substrate
contained large coral gravel in high proportion. T. hemprichii also formed a stable
meadow in a combined community with live Montipora digitata. Based on the above
findings, we introduce effective techniques, including some prospects, for seagrass bed
restoration suitable to the ecological characteristics of each species.
24.1044
Survival And Growth Of acropora Spp. in Nursery And After Transplantation At
Phi Phi Island, Krabi, Thailand
Lalita PUTCHIM* 1 , Nalinee THONGTHAM 1 , Hansa CHANSANG 1
1 Department of Marine and Coastal Resources, Phuket Marine Biological Center, Phuket,
Thailand
Mid-water coral nurseries have advantages particularly avoiding smothering by sediment
and small fragments were used causes little effect on donor colonies. This study aims to
determine survival and growth rates of coral fragments in nursery during nursing period
as well as after transplanted to natural substrate. One thousand one hundred and twenty of
two dominant species at Phi Phi Lae Island, Acropora grandis and A. formosa, were used
as seedlings. The average size of fragments was 4.6±1.2 cm. Survival and growth rate of
coral fragments were determined monthly. After 4 months in the nursery, total survival of
fragments was 95.8% and 94.8% for A. grandis and A. formosa respectively. There was a
significant difference of growth rate between two coral species (0.46±0.3 cm/month for
A. grandis, 0.19±0.18 cm/month for A. formosa) (t-test, p