11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 20: Modeling Concepts and Processes On Coral Reefs
20.802
Conceptual Models For Tropical Atoll And Cold Coral Lophelia Pertusa Reefs
Robert GEORGE* 1
1 George Institute, Wilmington, NC
Odum's models of food chain revealed trophiclinks in marine communities.However,the
interconnection between primary production, primary, secondary and tertiary consumers
remained complex. These models did not incorporate the human dimensions or
biophysical interactions. This author in collaboration developed a simpler conceptual
model with colleagues for the cold coral Oculina varicosa ecosystem, using rainbow
colors depicting trophic levels. This conceptual model focused on 'Ecosystem-based
Management'(EbM.)
This paper extends this simple conceptual model approach to coral reef ecosystems:
(1)Tropical Acropora spp. ecosystem in the Maldives atolls in the Indian Ocean and (2)
The deep-sea coral Lophelia pertusa (Linneus) bioherm, located at the northern tip of the
Blake Plateau (400 - 650 m) in the Northwestern Atlantic Ocean.The Maldives reefs were
severely impacted by bleaching events during the 1998 El Nino.On the contrary, the
azooxanthellate Lophelia pertusa bioherms off North Carolina, adjacent to the Agassiz
Coral Mounds(ACM)off cape Fear, are influenced by the Gulf Stream and the Western
Boundary Under Current, the former dominated by a single scleractinian coral Lophelia
pertusa and the latter dominated by the coral Bathypssamia tintinnabulum. Several
species of bathyal crustacean and fish are abundant in this ecosystem.
Two hypotheses are presented in this paper: (A) Acidification stress can impose reduction
in calcification rate and weaken coral skeletons and (B) Development of this conceptual
models will enable managers to recommend endangered species status to coral and fish
species and decision-makers to designate EFH-HAPC status that will assure better
protection of these vulnerable ecosystems and pave the way for developing precautionary
models.
20.803
A Trophic Model Of Overfished Fringing Coral Reefs in Nanwan Bay, Southern
Taiwan
Pi-Jen LIU 1 , Hsing-Juh LIN* 1 , Kwang-Tsao SHAO 2
1 Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan,
2 Research Center for Biodiversity, Academia Sinica, Taipei, Taiwan
Nanwan Bay, on the southern tip of Taiwan, is surrounded by well-developed fringing
reefs and attracts millions of tourists annually. In the past decade, some coral reefs in
Nanwan Bay have undergone rapid shifts to macroalgal dominance or to sea anemone
dominance. Using the Ecopath approach and network analysis, a mass-balanced trophic
model was constructed to analyze the structure and matter flows within the food web.
The fringing reef model was comprised of 18 compartments containing five integrated
trophic levels, with the highest trophic level of 3.45 for piscivorous fish. The mixed
trophic impacts revealed that macroalgae, benthic omnivorous invertebrates, and
piscivorous fish were the most-influential compartments in the reefs. Comparative
analyses with other fringing reefs demonstrated that total consumption and respiration in
Nanwan Bay were lower than those of other reefs. Fishery¡¦s mean trophic level, Finn¡¦s
cycling index, and mean trophic transfer efficiency of Nanwan Bay were also lower than
those of other reefs. However, total catch, net primary production, net system production,
and the net primary production: respiration ratio in Nanwan Bay were higher than those
of other reefs. The Nanwan Bay model showed an overfished status, in which less
organic matter is being conserved. The low abundance of fish might therefore have
resulted in a great proportion of flows not being transferred to higher trophic levels but
moving to detritus instead. Our results suggest that the authority should prohibit fishing
in the coral reefs of Nanwan Bay, or create more marine protection areas (MPA) to
restore fish community.
20.804
The Rites Of Passage in The Marine Corridors Of The Sulu Sea
Porfirio ALIÑO* 1 , Wilfredo CAMPOS 2 , Karen FRANCISCO 1 , Samuel MAMAUAG 1 , Rollan
GERONIMO 1 , Wilfredo LICUANAN 3 , Cesar VILLANOY 1 , Melchor DEOCADIZ 1 , Pacifico
BELDIA 2
1 University of the Philippines Diliman, Marine Science Institute, Quezon City, Philippines,
2 University of the Philippines Visayas, College of Arts and Sciences, Iloilo City, Philippines,
3 De La Salle University, Brother Shields Marine Station, Manila, Philippines
The Sulu Sea marine corridors are found at the cradle of the highest marine biodiversity areas in
the world. Reefs in the Verde Island Passage-Mindoro Strait-Calamianes Islands, The Balabac
Straits and the Cagayan Ridge area were investigated. Coral reef benthic assemblages and their
associated fish communities were assessed to provide the state of the reefs. Relative degrees of
the natural and human induced were evaluated. We looked at how the connectivity information
is crucial in the formulation of a strategic conservation agenda for the various governance levels
at each reef area. The utilization of no-take marine protected areas (MPA) as an entry point, in
conjunction with fisheries management helps to prioritize the conservation strategies at various
ecological and management scales.
Cagayancillo is in a better reef state vis-à-vis those in the municipalities Balabac and Mabini,
Batangas. On the other hand, most of the reef areas have exceeded its fishing capacity. Our
results suggest the expansion of no-take areas in the corridors need to be expanded to help
continue to facilitate interconnectedness. Fisheries Information to Sustain Harvests –
BioEconomic 2 (FISH BE2) network model simulations implicates the resiliency of these
marine corridors. Further increases in fishing capacity will lead to further decline and reflect on
the fishers daily catch rates. Marine corridors show the importance in allocating buffer areas for
particularly sensitive sea areas (PSSA) in conjunction with expansion of sizes of the existing
MPA.
20.805
Quantifying Environmental Influences On Coral Bleaching in The Florida Keys Using
Multi-Species Models
Susan YEE* 1 , Deborah SANTAVY 1 , Mace BARRON 1
1 ORD/NHEERL/Gulf Ecology Division, U.S. E.P.A., Gulf Breeze, FL
Differential susceptibility among reef-building coral species to temperature-induced mass
bleaching events can lead to community shifts and loss of diversity. We evaluated
environmental influences on coral colony bleaching from 1998-2005 in the Florida Keys, USA.
We used clustered binomial regression to develop models incorporating species-specific
responses to the environment in order to identify conditions and species for which bleaching is
likely to be severe. We evaluated three separate models incorporating environment, species
composition, and species-specific responses to environment, and showed observed prevalence
of bleaching reflects an interaction between species composition and local environmental
conditions. Environmental variables, including elevated sea temperature (Degree Heating
Weeks), solar radiation, and reef depth, explained much of the variability in colony bleaching
across space and time. The effects of environmental variables could only partially be explained
by corresponding differences in species composition. Species-specific models indicated
individual coral species responded differently to local environmental conditions and had
different sensitivities to temperature-induced bleaching. Acropora palmata experienced the
severest response to temperature, whereas for other taxa the response was fairly weak. For
many coral species, including Colpophyllia natans, Dichocoenia stokesii, Diploria strigosa,
Montastraea annularis, M. cavernosa, and Siderastrea siderea, bleaching was exacerbated by
high solar radiation. A reduced probability of bleaching in shallow locations for S. siderea may
reflect an ability to acclimatize to local conditions. Model development provides a useful tool
for quantifying the influence of the local environment on species-specific bleaching
sensitivities, identifying susceptible species, and predicting the likelihood of mass bleaching
events with changing environmental conditions.
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