11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 10: Ecological Processes on Today's Reef Ecosystems
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Impacts Of Sediment On Coral Recruitment At Koh Samui, The Gulf Of Thailand
Sittiporn PENGSAKUN* 1 , Wanlaya KLINTHONG 1 , Kanwara SANGMANEE 1 ,
Thamasak YEEMIN 1
1 Biology, Marine Biodiversity Research Group, Bangkok, Thailand
Changing land use practices in Koh Samui, Southern Thailand, have resulted in inputs of
sediment into the nearshore water. The present study aims to examine impacts of
sediment on coral recruitment. Sedimentation rates on coral communities of Koh Samui
were investigated in 2006-2007 by using sediment traps, a diameter of 5 cm and 11.5 cm
in length. Sedimentation rates varied temporally in a range of 6.21 (in February) - 24.52
(in November) mg/cm2/d. The sedimentation rates on coral reefs of Koh Samui were
relatively high. Field observations on coral recruits on natural reef substrates were
conducted to monitor changes of juvenile coral colonies. The highest diversity of coral
recruits was only 0.38 recriut/m2. The dominant juvenile coral colonies were Fungia,
Porites, Favites, and Favia. Mortality rates of juveniles coral colonies were very high. To
examine the impacts of sediment on settlement of corals, experimental settlement plates
consisted of 15x15 cm tiles in horizontal, oblique, and vertical positions were deployed.
The settlement tiles were submerged for two-month intervals. The density of coral
recruits on the lower surface of horizontal tiles was 117.37 recruits/m2 which was about
two times higher than that of the upper surface. The dominant coral recruits on settlement
tiles were Pocillopora damicornis and Porites spp. The results provide the scientific
evidence of effects of sediment on coral recruitment in the Gulf of Thailand.
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Spatio-Temporal Patterns Of Coral Recruitment in The Bolinao-Anda Reef
Complex, Northwestern Philippines
Maria Vanessa BARIA* 1 , Porfirio ALIÑO 1 , James GUEST 2 , Andrew HEYWARD 3
1 The Marine Science Institute, University of the Philippines, Quezon City, Philippines,
2 School of Biology, Newcastle University, NE1 7RU, United Kingdom, 3 Australian
Institute of Marine Science, Crawley, Australia
Coral recruitment is a major structuring factor of coral reef assemblages. Understanding
the early recruitment processes that maintain the diversity of reefs in the Philippines will
be crucial for the sustainability of this most diverse yet most threatened ecosystem. This
study assesses spatial and temporal coral larval settlement patterns in four selected areas
and two depths in the Bolinao-Anda reef complex, northwestern Philippines using
quarterly deployment of replicated settlement plates for 1 year from November 2006 to
November 2007. Variations in spatial and temporal patterns of early recruitment on the
tiles were observed among sites and depths. Coral spats were highest during the period
February to May 2007 with values ranging from 47 to 607.7 recruit m -2 among stations
(234.9 average recruit per m -2 ). This coincides with the peak in broadcast spawning
activity at these sites (March to June). Among the 4 sites, the southernmost site in
Caniogan, Anda consistently had the highest larval settlement. Unlike other sites,
Caniogan is relatively embayed site, protected from strong wave action. This feature may
enhance larval retention thereby increasing possibilities of successful larval recruitment.
Currently we are looking at the composition of juvenile and adult assemblages at all sites
and examining the mechanisms such as sedimentation inundation, algal overgrowth and
grazing and other disturbance which influence survivorship to its eventual juvenile and
adult assemblage.
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Prey Selectivity Of Coralliophila Abbreviata And C. Caribaea (Coralliophillidae,
Neogastropoda) in Morrocoy National Park, Venezuela. An Experimental Approach.
Carlos DEL MONACO* 1 , Estrella VILLAMIZAR 1 , Samuel NARCISO 2
1 Universidad Central de Venezuela, Caracas, Venezuela, 2 Fundacion por la Defensa de la
Naturaleza, Chichiriviche, Venezuela
Coralliophila abbreviata and C. caribaea are tropical gastropods of the Caribbean Sea. These
gastropods have shown themselves to be important corallivores. The objective was to evaluate
the prey selectivity of C. abbreviata and C. caribaea in some coral reefs of Morrocoy National
Park by experimental (C. abbreviata) and descriptive methods (C. abbreviata y C. caribaea). The
descriptive methods were utilized in the locations of Cayo Borracho, Cayo Peraza, Cayo
Sombrero, Playa Mero, Playuelita and Punta Brava. The experiment was realized in Cayo
Sombrero. We estimated coral abundance and richness, number of Coralliophila, and coral
species as associated by means of 12 quadrates of 1 m2 in 3 sites of each location. In the
experiment we used 8 exclusion cages with 5 coral colonies of different species equidistant to
10 individuals of C. abbreviata in each cage. As for the descriptive method, we observed in situ
a higher predator-prey relation between C. abbreviata and the hexacoral species M. annularis.
M. annularis presented 56,82% of the total interactions in all localities, followed by D. strigosa
(19,32%), A. agaricites (12,22 %), C. natans (4,55 %) and A. tenuifolia (3,13 %). C. caribaea
presented a higher predator-prey relation with the octocoral species E. caribaeorum (42,59 %)
and the hexacoral species C. natans (24,07 %), M. faveolata (11,11%), P. porites (7,41 %) and
D. strigosa (11,11 %). The experiment showed a major relation between C. abbreviata and M.
annularis because it exhibited 53,33 % of the total interactions, followed by C. natans (17,78%),
A. tenuifolia and D. strigosa (11,11% each) and A. agaricites (6,67%). The results of the
experiment coincided with the results of the descriptive methods indicating a prey selectivity of
C. abbreviata by M. annularis probably due to a major nutritional quality and tissue
regeneration rate.
Key words. Coralliophila sp, prey selectivity, coral reefs, Morrocoy National Park.
10.298
Tubiculous Coral Symbionts Induce Morphological Change And Enhance Growth in
montipora
Gerick BERGSMA* 1,2
1 Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa
Barbara, CA, 2 Moorea Coral Reef Long Term Ecological Research Program, Moorea, French
Polynesia
Coral morphology and growth rate drive reef accretion and production, and mechanisms
controlling coral structure regulate habitat for reef associated organisms. Processes that alter
coral morphology and growth can therefore significantly affect reef communities. In the
lagoons of Moorea, French Polynesia, tube-dwelling amphipods and polychaetes induce the
formation of long, finger-like branches in otherwise encrusting or plating species of Montipora.
I conducted surveys and field experiments to determine the extent to which these symbionts
alter Montipora’s morphology and growth. My surveys demonstrate that these symbiontinduced
formations (which I have termed “fingers” to distinguish them from ontogenetic
branches) are ubiquitous throughout the lagoons, and add considerable 3-dimensional structure
to the reefs. My experiments show that symbionts dramatically increase rates of linear
extension in fingers by creating novel substrate, effectively enhancing colony growth.
Furthermore, the induced morphology increases colony survival, and may alter the ability of
colonies to reproduce and compete for space. These results suggest that symbionts substantially
change reef structure, and likely impact reef community dynamics.
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