11th ICRS Abstract book - Nova Southeastern University

18-13
Response Of High Latitude Hermatypic Coral To The Rising Sea Water
Temperature At Daya Bay, South China's Guangdong Province
Hui HUANG* 1 , Jiansheng LIAN 1 , Jianhui YANG 2 , Xiubao LI 1
1 LMB, South China Sea Institute of Oceanology, Chinese Academy of Sciences,
Guangzhou, China, People's Republic of, 2 South China Sea Institute of Oceanology,
Chinese Academy of Sciences, Guangzhou, China, People's Republic of
Daya Bay is a semi-enclosed subtropical bay located in the southeast of the south China's
Guangdong Province. Its latitude is 22.5°N-22.9°N, covering an area of about 550 km 2 .
The water exchange with the ocean is low and the residence time of seawater is about 1
or 2 months. Two Nuclear Power Stations, situated in the mid-part of west coast of the
bay, began in commercial operation in the 1994 and 2003 respectively. The cooling water
plume flows into the bay and accumulatively elevates the sea water temperature of the
bay by about 1.1 degree Celsius, which is about the temperature rise of IPCC 2007's
projection for 2050. This provides a unique "in situ experiments" to explore the response
of hermatypic coral to the rising sea water temperature. Change of temperature scheme is
very sensitive because the distribution of hermatypic corals in Daya Bay is near their
north limit.
The percent cover and community structure of hermatypic corals in Daya Bay was
surveyed using line transect methods in 2007. Comparing the historical survey records in
1983~84, 1991, and 2002, a great change was observed. The live coral cover was 70% in
1983~84, then stabilized at ~30% after 1991, and slightly increase to 33~35% after 2005.
The dominant species was Acropora spp. in 1983~84 and theretofore, which was
replaced by Favia spp. after 1991. The percent cover of Acropora spp. and the total
species number was also increased after 2005.
The annual growth rates were estimated using X-radiography technique with coral
samples of Porites lutea. We found that the growth rates of the coral influenced by the
cooling water were 0.8mm/a greater than those unaffected.
Our results suggested that increasing sea water temperature may favor the growth and
development of hermatypic corals in high latitude area like Daya Bay.
18-14
A Ten-Year Study On Dynamical Structure Of A Sub-Tropical Coral Community
in Hong Kong Sar, China
Tze-wai TAM* 1 , Put O. ANG 1
1 Marine Science Laboratory, Department of Biology, The Chinese University of Hong
Kong, Hong Kong, Hong Kong
A long term monitoring programme of a sub-tropical coral community has been set up in
A Ma Wan, Tung Ping Chau Marine Park, Hong Kong and has been on going since May
1997 with nine fixed position 40 m long transects and 0.5 m x 0.5 m permanent quadrats
laid at every 5 m interval along each transect. The study is to provide the first-hand
information for understanding the natural variation of Hong Kong corals towards
physical disturbances and to serve as an important baseline for objective assessment of
human impacts on the local coral communities. At the beginning of the study, a total of
40 scleractinian coral species from 20 genera (12 families) was recorded. Over the tenyear
study (1997 - 2006), the coral community was subject to repeated physical
disturbances caused by tropical cyclones. Within the period from 1997 to 1999, the site
experienced the highest frequency of severe tropical cyclones and the strongest cyclone
to hit Hong Kong in the last 23 years (1984 - 2006). The coral cover was reduced
significantly after the cyclone impacts and the community never recovered to its original
state ever since. Cyphastrea serailia, Goniopora lobata, Montipora peltiformis and
Pavona decussata were the dominant species most highly affected by the cyclone
impacts. Significant shift in the coral community structure from Platygyra-Goniopora
dominant community to Pavona-Platygyra dominant community was also observed after
the cyclone impacts. Overall, the coral community was relatively stable and resistant
towards short-term but not long-term repeated disturbances. The community may also
have low resilience towards more severe disturbances in the future. Preserving the
resilience of coral communities/species in Tung Ping Chau should be one of the main
goals of coral conservation strategies for the island marine park.
Oral Mini-Symposium 18: Reef Status and Trends
18-15
Decadal Scale Changes in Coral Reefs in Quintana Roo, Mexico
Thaddeus NICHOLLS* 1 , W. David LIDDELL 1
1 Geology, Utah State University, Logan, UT
The east coast of Quintana Roo, Mexico is bordered by the barrier-fringing reefs of the
Mesoamerican reef system. Spanning over 1126 km from the tip of the Yucatan Peninsula
south to the Bay Islands off the Honduran coast, this reef system is the largest in the Atlantic,
and the second largest in the world. The Caribbean coast of Quintana Roo was covered by
semi-humid tropical rainforest until 1970, when coastal development including road and resort
construction broke ground. Sixty percent of this area had been cleared by 1988 for the
“megaproject” known as the “Cancun-Tulum Touristic Corridor,” or “Mayan Riviera.” The
long term impact of this development on the coral reefs of this area had not been quantified. In
1992 data on community composition were collected from two areas, Akumal and Chemuyil,
ranging from 4.8-33.5m depth. These areas were revisited in 2005 and data were collected in
the same fashion and at the same depths as in 1922 to determine if coastal development has had
a significant impact on the coastal reefs. Chi squared analysis determined that the community
composition data collected in 1992 are significantly different from those data collected in 2005
(alpha value 0.05). Coral cover in Chemuyil at 33.5m declined from 44.1% to 33.3%. Algae
(including macro algae, filamentous algae, and erect coralline algae) coverage at the same site
increased from 29.1% to 46.7%. Similar trends are observed at accompanying sites. Anecdotal
accounts suggest that the trends exhibited by the reefs are due to nutrification by septic water
flowing through the highly porous karst limestone of the Yucatan Peninsula since there were
few signs of damage to the reefs other than a very high percentage of algae coverage.
Furthermore, fish populations appeared to be relatively healthy.
18-16
pocillopora Recovery At Devil’s Crown, Galápagos Islands, Ecuador, Following
Extirpation Associated With The 1982-83 El Niño-Southern Oscillation
Joshua FEINGOLD* 1 , Peter GLYNN 2
1 National Coral Reef Institute, Nova Southeastern University Oceanographic Center, Fort
Lauderdale, FL, 2 Department of Marine Biology and Fisheries, Rosenstiel School of Marine and
Atmospheric Science, University of Miami, Miami, FL
In 1982-83 a severe El Niño-Southern Oscillation (ENSO) event killed 95% of the scleractinian
corals in the Galápagos archipelago. Over 99% coral mortality occurred at the Devil’s Crown
study site located within the flooded (2-4m depth) center of a small (156 x 100m), emergent,
dormant volcanic cone off the north coast of Floreana Island. Also at this site, a structural reef
composed primarily of the branching coral Pocillopora spp. was lost from contrary wave action
combined with primary and secondary biological disturbances associated with ENSO. For the
subsequent 11 years Pocillopora was not observed there, however 5 colonies were seen in May,
1995. Since then the number and size of colonies were monitored approximately annually.
Coral colony surface areas were determined following two methods: direct measure during
snorkel surveys to determine maximum width and length (1995-2003), and digital photography
to obtain 2-D images (2004 & 2007). These images were converted to projected surface area
using the program CPCe. The numbers of Pocillopora colonies increased from 5 in 1995 to 154
in 2007, with total colony surface area increasing from 849 cm2 to 37,772 cm2 (3.8m2) over
the same period. Colonies initially appeared via sexual recruitment, probably from source
populations located upcurrent, and now larger colonies are fragmenting and forming localized
aggregations. This long term (25y) monitoring reveals slow initial recruitment from 1995 to
2002 followed by recent accelerated increases in Pocillopora colony number and surface area.
This suggests that Pocillopora may once again attain population densities sufficient to form reef
structures, an unusual prospect considering the widespread reports of coral loss worldwide.
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