11th ICRS Abstract book - Nova Southeastern University

18.682
Seasonal Investigation On Stability Of Coral-Algae Interactions in Fringing Reefs
Of The Northern Red Sea
Andreas HAAS* 1 , Florian MAYER 1 , Malik NAUMANN 1 , Carin JANTZEN 1,2 ,
Mohammed AL-ZIBDAH 3 , Christian WILD 1
1 Coral Reef Ecology Work Group (CORE), GeoBio-Center LMU München, Munich,
Germany, 2 Center for Tropical Marine Ecology (ZMT), Bremen, Germany, 3 Marine
Science Station, Yarmouk University, Aqaba, Jordan
It is reported from many reef locations that corals are replaced by benthic algae, but not
very much is known about the factors relevant for the stability of direct interaction
between corals and benthic algae in the reef. This paper presents corresponding in-situ
monitoring data from fringing reefs in the Northern Red Sea. During four seasonal
expeditions, line point intercept and belt transect surveys were conducted at reefs close to
Aqaba, Jordan, and Dahab, Egypt. This revealed that 25 % (Aqaba) and 40 % (Dahab) of
all observed reef-building corals were in direct interaction with benthic algae. In Aqaba,
in between 5 and 10 m water depth, the macro algae Caulerpa and Peyssonnelia as well
as different turf algae consortia represented almost 100% of the algae species involved in
direct interactions with corals. The stability of these interactions was monitored at
marked locations in the study area during two field expeditions in November 2006 and
August 2007. For that purpose the projected total living coral area was measured using
underwater photography and subsequent image analysis. In total 40 natural coral-algae
interactions were monitored over a total period of 16 months, whereas solitary colonies
and algae transplants were used as controls. Stability of coral-algae interaction proved to
be highly variable between seasons with fast overgrowth of corals by algae in fall and
winter and almost stagnation during summer. The results of this study also indicate that
benthic filamentous turf algae are most frequently (up to 80%) involved in interactions
with corals and can cause most damage to corals in-situ. Slow-growing massive species
showed more resistance against algal influence than branching corals. These findings
provide some first fundamental data in order to contribute understanding the underlying
mechanisms of phase shifts in coral reefs.
18.683
A Photographic Method For Analyzing Areal Chlorophyll And Bleaching Status Of
The Coral Stylophora Pistillata
Shachar KOREN* 1 , Zvy DUBINSKY 2
1 Life Science, Bar Ilan University Israel, Kfar-Saba, Israel, 2 Life Science, Bar Ilan
Univerity, Ramat Gan, Israel
With the increasing frequency and severity of coral bleaching events, this phenomenon
has been documented and studied by scientists around the world. Methods to quantify
bleaching status are based on sacrificing the samples being tested or using expensive
equipment (like PAM).
In recent years, the performance of digital cameras in image processing has improved and
they have become more affordable, thus, a new, economical and nondestructive way to
monitor bleaching and recovery processes in coral tissues is becoming available to
conservationists and researchers.
In the present study, we report a reliable bioassay for computerized quantification of areal
chlorophyll density in corals. Demonstration of the method’s robustness and reliability
was done by studying experimentally induced bleaching and subsequent recovery in the
common Red Sea coral Stylophora pistillata from the Gulf of Eilat (Aqaba). We used a
regular digital camera and standard computer software, both inexpensive and easily
available. The proposed bioassay could be used on any coral to rapidly and economically
gather data on coral bleaching and disseminate them.
We hope that this will help scientists gain real-time information on large-scale bleaching
events, even in remote reefs, using inexpensive means
Poster Mini-Symposium 18: Reef Status and Trends
18.684
Quantitative Habitat Characterization And Benthic Assemblage Structure Of Deep-Water
Scleractinian Reefs Off Eastern Florida
Kartick SHIRUR* 1 , Charles MESSING 1 , Carmen RODRIGUEZ 1 , Joshua FEINGOLD 1 , John
REED 2 , Sandra BROOKE 3
1 Nova Southeastern University, Dania Beach, FL, 2 Harbor Branch Oceanographic Institute,
Florida Atlantic University, Ft. Pierce, FL, 3 Ocean Research and Conservation Association, Fort
Pierce, FL
Eight deep-water coral sites were surveyed in November 2005 during 11 dives with the
Johnson-Sea-Link submersible along the eastern continental margin of Florida from St.
Augustine to Miami. Sites included unconsolidated sediment/coral bioherms, rocky lithoherms
and the Miami Terrace escarpment. Photographic transects using high-resolution video and
digital still images documented each site. Observations were made over a depth range of 282-
871 m. In situ temperatures ranged from 6 to 9ºC. We examined 31 video transects and
extracted over 2500 images for habitat characterization and quantitative analyses of percent
coverage by substrate type and densities of major macrobenthic assemblage components using
the Coral Point Count software (CPCe). All organisms larger than ~10 cm in each image were
identified to the lowest possible taxonomic level. Substrate categories included living and dead
standing coral, coral rubble, sediment, rock rubble, and hard substrate (e.g., pavement,
boulders). The branching azooxanthellate scleractinian corals Lophelia pertusa and
Enallopsammia profunda dominated five and six sites, respectively. The percentage of live
coral varied among sites, regardless of the dominant species in that area. Sites dominated by L.
pertusa showed greater accumulation of sediment, while E. profunda was most often associated
with lithoherms, though both species were observed in both habitats. Distributions of corals and
other organisms were related to depth, bottom topography and physical environmental
conditions. Associated taxa included Madrepora oculata (Scleractinia), Keratoisis flexibilis and
Plumarella pourtalesii (Octocorallia), Stylasteridae, and numerous Hexactinellida and
Demospongiae (e.g., Phakellia sp., Pachastrella sp., Aphrocallistes sp. and Heterotella sp.).
The results will be applicable to managers in developing plans for conservation and protection
of these fragile deep-water resources.
18.685
2007 Coral Reef Status in The Union Of Comoros
Said AHAMADA* 1,2
1 ICZM, ReCoMap, Moroni, Comoros, 2 Marine Environment, AIDE NGO, Moroni, Comoros
AIDE (Association d’Intervention pour le Developpement et l’Environnement) NGO with
support from the Indian Ocean Commission, is carrying out coral reef monitoring since 1997 in
the 3 Islands (Grande Comore, Moheli and Anjouan) of the Union of Comoros South Western
Indian Ocean, following Global Coral Reef Monitoring Network protocols.
Results from 10 sites are discussed in this paper. In 2002 (4 Years after the 1997/1998
bleaching event) coral recovery was very low. Actually (10 years later) the general trend is to
the initial status with more than 70% coral cover in some sites as Wani Anjouan, Mitsamiouli
Grande Comore and Walla Moheli.
Some sites as Bimbini Anjouan and Chindini Grande Comore show low coral cover around
24% and are under higher pressure as over fishing, sedimentation and trampling.
Coral reef are in better health in sites of the Marine Park of Moheli ( from 50 to 72% coral
cover) than in other sites of the same Islands with less than 30% ( Fomboni and Hoani).
Coral bleached (1 to 10%) from recent events as 2004/2005 did rapidly recover especially those
with less stress from human activities.
Socioeconomic assessment have also been conducted under CORDIO supervision and are being
cross analyzed with the biophysical dada through ARC GIS tools to help take adequate
measures for adaptive management of the reefs and associated resources.
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