11th ICRS Abstract book - Nova Southeastern University

8.222
δ 13 C and δ 15 N values for branching coral reefs at the Berau Marine Conservation
Area in East Kalimantan, Indonesia
Handoko Adi SUSANTO* 1 , Masaaki YONEDA 2 , Hiroko KOIKE 1
1 Department of Environmental Changes, Graduate School of Social and Cultural Studies,
Kyushu University, Fukuoka-shi, Japan, 2 Japan Wildlife Research Center, Tokyo, Japan
To understand 13C and 15N�values between zooxanthellae and coral tissue, branching
coral reefs Porites spp., Seriotophora sp. and Stylophora sp. were collected from the
Berau Marine Conservation Area (MCA), East Kalimantan, Indonesia. The study was
also intended to examine the affect of sedimentation from the Berau River mouth to the
coral reef conditions. Zooxanthellae was separated using sonication method, and coral
tissue was obtained by decalcification method from their coral skeleton. Carbon and
nitrogen isotope values showed that most of the coral tissues had higher 15N values
than those of zooxanthellae. It indicates that zooxanthellae must be the main source of
nutrient for the coral tissue. Samples collected from three localities, designated as the
nearest (Locality 1), medium distance (Locality 2) and the farthest (Locality 3) from the
Berau river mouth, indicated that 13C values�of the zooxanthellae and the coral tissue
had no significant different among localities, but 15N values were statistically
significant. The highest 15N value found from locality 2 could be due to the
anthropogenic impact from Derawan Island (48 ha) which is inhabited by about 1500
people. The higher 15N values in locality 1 were an indication of the affect of
sedimentation from the Berau River that served as nutrient sources compare with locality
3 which is mainly marine condition.
8.223
Seasonal Changes in Bacterial Communities Associated With Acropora Palmata
Surface Mucus And Surrounding Water Column
Kim RITCHIE* 1 , Jonathan ONUFRYK 1 , Erich BARTELS 2 , Joel THURMOND 1
1 Mote Marine Laboratory, Sarasota, FL, 2 Mote Marine Laboratory, Summerland Key, FL
The Caribbean Elkhorn coral, Acropora palmata, is an important primary producer and
shallow water framework builder in the Florida Reef Tract. This coral species is
extremely sensitive to various stressors, including disease, elevated temperatures, and
storm damage. The severe population declines of A. palmata due to secondary responses
to these stressors (disease and bleaching) have changed the composition, structure, and
function of the Florida Keys coral reef ecosystem. In order to address temporal shifts in
coral sensitivity and microbial community dynamics in surface mucus and the
surrounding water column, both A. palmata and sea water was sampled monthly from
2005 through 2007 at three sites at Looe Key Reef in the lower Florida Keys. Assays
performed included mucus inhibition of pathogenic tester strains, vibrio ratios estimated
from dilutions inoculated onto TCBS plates, and shifts in antibiotic producing bacteria
associated with coral surfaces. Although there were not significant or consistent trends in
antibiotic qualities or antibiotic producing bacteria on coral surfaces, results show a
general trend towards an increase in Vibrio spp. in the water column and on coral
surfaces as temperatures increase. Continued monthly to quarterly monitoring of corals
will provide much needed information on microbial community dynamics of this
sensitive species.
Poster Mini-Symposium 8: Coral Microbial Interactions
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Realistic measure of the supply of bacteria from the water column to a coral
Michael SWEET* 1
1 School of biology, Newcastle University, Newcastle upon tyne, United Kingdom
This study investigates the controls on bacterial community development and organisation on
the surface mucus layer (SML) of reef corals. Various factors may influence the SML bacterial
community of corals, including production of antimicrobial chemicals, supply of bacteria from
the water column, environmental conditions and mucus composition and production rates.
Mucus production is particularly important as it represents both the availability of Carbon and
Nitrogen and the dynamics of the SML as a physical barrier, entrapment surface and growth
medium. Although the SML of corals is believed to be a highly dynamic layer, it appears to
support a distinct resident bacterial community rather than one resulting from passive settlement
and entrapment of water-borne bacteria. Comparisons between the bacterial species diversity
found in the surrounding water column and coral mucus show very little overlap. Previous
studies have investigated supply of bacteria from the water column using discreet (Niskin
bottle) samples, which do not adequately represent either the diurnal and longer-term temporal
variation in the water column or the spatial scale and position of corals at the benthos. To
investigate the water column supply in this study, continuous and composite (periodic) in situ
sampling was undertaken using modern sample methods. A peristaltic pump sampler and PTFE
tubing was utilised to sample continuously direct into Sterivex GP filter units stored on ice. The
use of a peristaltic pump system enabled the sample inlet to be precisely positioned and flow
rates to be controlled to approximate the natural delivery rate from the water column due to
tidal and wind-driven currents. The bacterial 16S rRNA gene diversity was routinely monitored
using polymerase chain reaction (PCR)/ denaturing gradient gel electrophoresis (DGGE)
techniques, along with selective clone libraries and sequence analysis.
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Transitions in Vibrio spp. populations correlate with human impact in the Northern Line
Islands
Robert SCHMIEDER* 1 , Tracy MCDOLE 1 , Elizabeth DINSDALE 1 , Matthew HAYNES 1 ,
Forest ROHWER 1 , Robert EDWARDS 2
1 Department of Biology, San Diego State University, San Diego, CA, 2 Department of Computer
Science, San Diego State University, San Diego, CA
The initial microbiological survey of the Northern Line Islands showed most cultured Vibrio
species were found on Kiritimati, fewer on Tabuaeran and Palmyra, and least on Kingman.
These islands are situated in a North/South gradient (from 0-6oN), where Kiritimati is the most
southerly and largest and Kingman is the most northerly and smallest. These islands also
display a gradient of human activity where Kiritimati has the most human activity and Kingman
is unpopulated and protected from fishing. Tabuaeran and Palmyra are intermediates in all
variables. In contrast to the culturing results, a culture-independent survey by metagenomics –
randomly sequencing environmental DNA from these islands – showed a relatively consistent
distribution of Vibrio spp. at each island. Neither the culturing nor the metagenomics could
accurately identify the exact species present, so a multi-locus sequencing approach (MLSA)
was used to analyze the water samples at each island. This analysis demonstrated that there is a
consistent background of Vibrio spp. present everywhere and detectable by metagenomics, and
supplemental strains present at the specific locations where Vibrios were readily cultured, i.e.
on Kiritimati. To determine whether the changes in Vibrio population were biogeographic or
human influenced, both culture-dependent and culture-independent surveys were conducted
around Kiritimati Island were conducted. By studying Kiritimati only, latitudinal and island size
effect was removed, but variation in human activity still remained. These surveys recapitulated
the results of the previous analyses, and furthermore demonstrated a clear correlation between
human population, Vibrio counts, and Vibrio spp., but no correlation with other prevailing
factors (latitude, temperature, island size etc).
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