11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 4: Coral Reef Organisms as Recorders of Local and Global Environmental Change
4.55
Deep-Sea Corals From The Straits Of Florida As Proxy Indicators Of Bottom
Conditions in The Florida Straits
Angela ROSENBERG* 1 , Peter SWART 1 , Gregor EBERLI 1 , Mark GRASMUECK 1 ,
Thiago CORREA 1
1 MGG, University of Miami, Miami, FL
Recent studies have shown the presence of large accumulations of non-zooxanthellate
corals growing in mounds (up to 120 meters in height) scattered across the Straits of
Florida at depths of up to 800 m. The surfaces of these mounds are covered in live
corals, but the corals in the mounds themselves can be several 1000s of years old. Hence
combined with appropriate dating, these mounds offer the opportunity to obtain a glimpse
into variations in environmental conditions over this time period. This study reports
high-resolution geochemical analyses ( 18O, � C, Sr/Ca, Ba/Ca, and Mg/Ca) of the
coral Lophelia pertusa growing in these environments and interprets these data in terms
of changes of salinity and temperature. These data have been obtained by using a New
Wave micromill to excise material from longitudinal sections of previously live
specimens of L.pertusa. This material was then processed for stable carbon and oxygen
isotopes (Finnigan Delta-Plus) and for minor elements (Inductively Coupled Plasma
Optical Emission Spectrometer; Varian Vista-Pro). The Sr/Ca ratio of these corals can
be interpreted as indicating principally a temperature driven signal, while the 18O
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reflects both temperature and 18Ow ( O of the water). These parameters can in turn
be related to variations in the strength of the near bottom current pattern.
4.56
Opposed Trend Of Skeletal Carbon Isotopic Ratios Found in Two Different Coral
Species Collected From The Same Site: Genus-Dependent Responses
Michiyo SHIMAMURA* 1 , Kiseong HYEONG 1 , Tsuyoshi WATANABE 2 , Tomohisa
IRINO 2 , Chan-Min YOO 3 , Woong-Seo KIM 1
1 Korea Ocean Research and Development Insitute, Ansan, Korea, Republic of,
2 Hokkaido University, Sapporo, Japan, 3 Korea Ocean Research and Development
Insitute, Ansan, Japan
In order to better understand the controlling factor of δ13Cc, two different coral species,
Porites sp. and Platygyra ryukyuensis, were collected at the exactly same site from
Ishigaki Island, Japan, and analyzed for δ13Cc and δ18Oc. In an effort to develop paleoenvironmetal
proxy in mid-latitude region north of 30°N, Platygyra, one genus of
faviidae corals that dominate in mid-latitude region, were analyzed for the study together
with Porites, the most common and faithful coral proxy known up to now. The results
were compared with observed environmental variables.
As expected, both coral’s δ 18 Oc showed variations well matching observed SST. On the
other hand, δ 13 Cc variations were opposite to each other between Porites and Platygyra.
Porites δ13Cc shows a clear seasonal fluctuation matching that of solar radiation, high in
summer and low in winter. In contrast, δ13Cc of Platygyra was low in summer and high
in winter with weaker seasonality. Both colonies had been exposed to same
environmental conditions during growth period, so these opposed trends should be
attributed to factors other than environments, such as kinetic isotope effect depending on
calcification rate or species-dependent responses against same environmental condition.
Skeletal density, extension rate and calcification rate were estimated and compared with
isotope variations for both species. However, no clear relationships were found between
these factors and δ 13 Cc.
These results suggest following possibilities: 1) Different symbiotic relationship between
coral and zoothantellae and 2) Coral diet variation depending on genus (or species).
Probably, these are key factors that controls spatial distribution of each coral species.
4.57
Preliminary assessment of the impact of solid waste on reef flat gastropod community in
Talim Bay, Batangas, Philippines
Alexander ALOY* 1 , Benjamin VALLEJO JR 1
1 Environmental Science and Meteorology, University of the Philippines, Quezon City,
Philippines
Stratified quadrat surveys were conducted randomly over four plots on an intertidal reef flat and
beach in Talim Bay in Batangas, Philippines for gastropods, other macro-invertebrates, solid
wastes and organic debris. In this area some beaches are regularly cleaned by beachfront
leaseholders. Epifaunal data were recorded as absolute quadrat density and while relative spatial
cover was recorded for organic and inorganic debris and garbage. We developed rapid methods
in measuring ambient abiotic parameters in the intertidal substrate like the oxic layer of the sand
(i.e. 10 cm from surface) and slope using a mechanical angle finder level. The plots were
selected based on the degree of disturbance due to the presence of solid waste material
deposited in the upper areas (e.g. “swash zone”) of the reef flat. We postulate that the presence
of garbage (e.g. mostly composed of plastic sachets, plastics and bottles) affects the spatial
distribution and feeding ecology of macrofauna, thus negatively decreasing gastropod
community diversity. A total of five species of intertidal snails were present. A simple
ordination procedure (PCA) was used to explore the diversity patterns of macrofauna over
various quadrats and sampling areas. A species of Nassarius was the most commonly occurring
species even in the most garbage-impacted reef flats. Other gastropods include Polinices, Oliva
and Heliacus while other macrofauna were soldier crabs and Arcaster typicus all of which were
associated with “regularly-cleaned” intertidal zones. A canonical correspondence analysis
resulted into a general pattern of inverse corrrelation between garbage-debris cover with the
oxic layer properties of the sand.
4.58
150 Years of Coral Growth Rates and Water Quality on the Mesoamerican Reef
Jessica CARILLI* 1 , Richard NORRIS 1 , Konrad HUGHEN 2 , Nancy PROUTY 3
1 Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA,
2 Woods Hole Oceanographic Institution, Woods Hole, MA, 3 Pacific Science Center, United
States Geological Survey, Santa Cruz, CA
We report coral growth rate data derived from 96 cores of Montastrea faveolata from the
Mesoamerican reef spanning the last 150 years. X-rays reveal a severe slowing or hiatus in
growth rate, or partial mortality event in every core in 1998. This growth anomaly is coincident
with severe bleaching related to El Niño warming. Previous El Niño events did not produce
such severe bleaching events, and no growth anomalies are seen prior to 1998. In late 1998,
Hurricane Mitch passed over Honduras, causing massive flooding, freshwater plumes and
sedimentation onto the reef. Mitch undoubtedly affected the Mesoamerican corals, as runoff
plumes are detected in satellite images at all of our sites. However, the presence of anomalous
growth rates during 1998 in corals from Florida and Mexico underscores the severity of this
worldwide bleaching event.
Based upon preliminary master chronologies, growth parameters decrease over the length of the
record at the sites closest to the largest sources of terrestrial runoff. At sites farther from runoff
sources, growth increases. This may indicate that the corals at the more sediment-laden sites
have reached a threshold in terms of a response to runoff, and that further increases over time
have reduced growth rates. In contrast, increasing growth rates at sites further from the
mainland implies that poor overall reef health at these more distal sites may not be due to
runoff, but instead climate change, disease, overfishing, or other impacts. Coral geochemical
records of water quality support this interpretation; Ba/Ca shows an increase in terrestrial runoff
over the 20 th century, and a lower overall amount of terrrestrial material at the offshore sites. In
addition, coral oxygen isotope records indicate increasing freshwater runoff at the landward
sites.
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