11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 26: Biodiversity and Diversification of Reef Organisms
26.1214
Fish Community Structure in Two Coral Formations From Malpelo Island,
Colombian Pacific.
Adriana ALZATE-VALLEJO 1 , Fernando A. ZAPATA* 1
1 Department of Biology, Universidad del Valle, Cali, Colombia
The structure of a coral reef fish community in a Tropical Eastern Pacific oceanic island
is described for the first time. To that end visual censuses were done on two coral
formations of Malpelo Island, in the Colombian Pacific. Out of a total of 66 species
observed at both sites combined, 51.5% of them were observed on both, 36.4% were
observed only at El Arrecife and 12.1% were observed only at La Nevera. The species in
common made up > 95% of the total abundance in each community, in each case
characterized by having a few highly dominant species and many rare species. The
distribution of abundance (log-normal in both cases), α-diversity, trophic structure, and
taxonomic structure were similar at both sites. However, total species richness was
greater at El Arrecife (60 species) than at La Nevera (42 species), which can be partially
explained by a greater sampling effort and possibly a greater β-diversity due to a broader
depth range and more pronounced coral zonation at El Arrecife than at La Nevera. This is
supported by results of an analysis of similarity in community composition and species
abundance that reflected differences in habitat and depth between sites.
26.1215
Diversity Of Symbiodinium In Mesophotic Coral Communities On The Great
Barrier Reef
Pim BONGAERTS* 1 , Thomas BRIDGE 2 , Eugenia SAMPAYO 1 , Norbert
ENGLEBERT 1,3 , Tyrone RIDGWAY 1 , Mauricio RODRIGUEZ-LANETTY 1 , Jody
WEBSTER 2 , Ove HOEGH-GULDBERG 1
1 Centre for Marine Studies, University of Queensland, Brisbane, Australia, 2 School of
Earth and Environmental Sciences, James Cook University, Townsville, Australia,
3 IBED, University of Amsterdam, Amsterdam, Netherlands
The large variability in light availability in the underwater realm provides an important
axis for niche diversification of light-dependent biota on tropical coral reefs. As
irradiance decreases with increasing depth so does the variability in available irradiances
at a specific depth, which has been correlated to a drop in the diversity of the lightdependent
benthos, such as scleractinian corals. Whilst the algal symbionts
(Symbiodinium) that are associated with scleractinian corals can be specific to their host
species, they have also been shown to be specific to certain depth/light environments. In
this study we identify the algal symbionts associated with corals on the mesophotic reef
to determine community diversity of Symbiodinium at previously unstudied depths. This
was done using ITS2 rDNA and denaturing gradient gel electrophoresis (DGGE). A total
of 76 corals were collected on board the RV Southern Surveyor from depths between 50-
75m through dredge sampling on three sites along the Great Barrier Reef margin (Ribbon
Reefs, Noggin Pass and Hydrographer’s Passage). Collected coral were mostly identified
as belonging to the genera Montipora, Leptoseris, Seriatopora, with a few members of
the genera Pocillopora, Acropora and Galaxea. The results provide new insights on the
community structure of Symbiodinium in a understudied yet important coral habitat. In
addition, it is envisaged that the results will aid in understanding whether the mesophotic
reef constitutes a distinct habitat with its own specialized coral and symbiont community
or whether it is a mere extension of the shallower reef.
26.1216
Distribution Of The Family Pomacentridae in The Depth Gradient Of A Coral Reef in Isla
Larga, San Esteban National Park, Venezuela.
Lisette MOLINS* 1 , Jose RODRIGUEZ 1
1 Universidad de Carabobo, Valencia, Venezuela
The main objective of this study was to determine whether or not there is a distribution pattern
among the species of the family Pomacentridae along the depth gradient in a coral reef of Isla
Larga, San Esteban National Park, Venezuela. Visual census were carried out using the transect
method with observation stops in different depth strata, where the species of the family
Pomacentridae were identified. Additionally, a behavioral study was carried out to determine
the importance of the competition among congeners in the establishment of this pattern. Nine
species were recorded, where the most abundant was Stegastes partitus followed by S.
planifrons. A differential distribution was observed along the depth gradient, in which S.
adustus and Microspathodon chrysurus were located mainly up to 1m of depth. In the range
from 3 to 6m, up to the 80% of the pomacentrids were represented by S. planifrons and S.
partitus, which diminished their abundance between 9 and 12m, as S. variabilis increased.
There was not a clear relationship between the substrata and the distribution of the
pomacentrid’s species, although in general the most abundant substratum in the reef was the
coral Montastraea annularis as well as surfaces of dead coral covered with filamentous algae.
The composition, distribution and abundance of the species of the family Pomacentridae
suggests a close relationship with depth, while the interspecific competition does not seem to be
a regulating factor in the described distribution, since it was mainly intraspecific. It is possible
that this family’s distribution is regulated by other factors such as the establishment of larvae
and of juveniles in different areas of the reef.
26.1217
Species Richness Of Marine Benthic Habitats in South Florida
Sitti Zayda HALUN* 1 , James FOURQUREAN 2
1 Department of Biological Sciences and Southeast Environmental Research Center, Florida
International University, Miami, FL, 2 Biological Sciences and Southeast Environmental
Research Center, Florida International University, Miami, FL
A survey of species diversity of primary producers of benthic habitats in South Florida was
conducted in 350 randomly chosen sites from June to September of 2007 using a modified
Braun-Blanquet technique. Ten 0.25 m 2 quadrats were placed randomly along a 50-m transect
placed in a north-south direction at each site. All species occurring in the quadrat were listed
and a ranking based on abundance of the species in that quadrat was assigned. Seagrass
materials were collected at each site and analyzed for elemental composition (carbon, nitrogen
and phosphorus). Plant tissue stoichiometry was used as an indicator of the fertility of the
ecosystem. The results suggest that species richness was highest at intermediate fertility.
568