11th ICRS Abstract book - Nova Southeastern University

7-1
Patterns of Coral Diseases in the Florida Keys from 1998 – 2005
Deborah SANTAVY* 1 , Susan YEE 1 , Mace BARRON 1
1 Gulf Ecology Division, US EPA, NHEERL, Gulf Breeze, FL
Diseases have been identified as a major threat to reef-building corals causing morbidity
and mortality. Increased mortality has lead to degradation, especially those reefs
dominated by several susceptible species. Increased morbidity has reduced the health of
reef-building corals making them more vulnerable to other environmental stressors.
Reported incidence, prevalence, and distribution of coral diseases have been greatest
from the tropical Western Atlantic, with emergent coral diseases, such as aspergillosis
and serratiosis originating from terrestrial sources. Epizootiological studies assessed the
prevalence of dominant coral diseases in the Florida Keys reef tract from 1998-2005,
from the Dry Tortugas to the Upper Keys. Annual assessments were repeated at
permanent sites in mid-summer throughout the area. Data were adjusted so coral
community composition, specifically the absence of susceptible species, did not bias the
results. Canonical correspondence analyses revealed coral diseases patterns related to
spatial and temporal parameters. Reef depth was the most discriminating parameter for
all coral diseases surveyed. White plague and white-band disease had the highest
prevalence on deeper reefs, whereas black-band disease was most prevalent on mid-depth
reefs, and red-band disease and white pox were most prevalent on shallow reefs. Whiteband
disease had the highest prevalence in the early years, whereas dark-spots disease
had increased incidence in the later years of the study. Dark-spots and yellow-blotch
diseases were more common in the Dry Tortugas, whereas black-band disease had the
highest prevalence in the Middle Keys. One of the first steps in identifying and managing
health threats of reefs is to establish disease prevalence and incidence to understand
patterns and associate them with other variables to determine causative factors. In
tropical marine systems prevention or control of coral disease can assist in precluding the
collapse of important ecological functions and ecosystem services.
7-2
The Role Of Diseases in Coral Community Structure Shifts in Mexican Caribbean
Reefs
Eric JORDÁN-DAHLGREN* 1 , Rosa RODRÍGUEZ-MARTÍNEZ 2 , Adan Guillermo
JORDÁN-GARZA 3 , David M. BAKER 4 , Jason ANDRAS 5 , Leonardo VAZQUEZ-
VERA 6
1 ICMyL, UAPM, Universidad Nacional A. de México, Puerto Morelos, Mexico, 2 ICMyL,
UAPM, Universidad nacional A. de México, Puerto Morelos, Mexico, 3 ICMYL, UAPM,
UNiversidad Nacional A. de México, Puerto Morelos, Mexico, 4 Ecology and
evolutionary Biology, Cornell University, Ithaca, NY, 5 Ecology and Evolutionary
biology, Cornell University, Ithaca, NY, 6 ICMyL,UAPM, Universidad Nacional A. de
México, Puerto Morelos, Mexico
Montastraea annularis, M. faveolata and M. franksi, the major local coral reef builders
after the demise of Acroporids in the Mexican Caribbean, has decreased more than half in
a twenty years span; presumably due to diseases. Recent data (2005-2007) from highly
replicated permanent sites spread over a 200km reef tract shows relatively large rates of
whole colony and partial mortality for these species, both within and between sampling
sites. Yellow Blotch syndrome appears to be the major cause of the observed mortality
patterns, although other disease signs also play a role. Species of Acropora, Diploria and
Colpophyllia natans, the other potentially important reef builders are also being severely
affected by other diseases. In contrast Agaricia agaricites, Porites astreoides and
Siderastrea siderea while not being immune to coral diseases show a much higher
resistance and mortality rates are comparably low; becoming the dominant components in
reefs down to 15m deep. Although variable among sites, comparisons of species size
structures indicates that local shifts in dominant species appears to be related to higher
survival rates, rather than to increased recruitment rates. Analyzing linkages of the
observed patterns with site relative degree of local development, protected and nonprotected
status and local thermal anomalies shows mixed trends. These findings suggest
that global and regional drivers of environmental deterioration may have a stronger
influence than local ones in the study area.
Oral Mini-Symposium 7: Diseases on Coral Reefs
7-3
Recent Changes To Montastraea Annularis And M. Faveolata Populations In
Southwestern Puerto Rico And Associated Islands From Disease And Bleaching
Andrew BRUCKNER* 1 , Ron HILL 2
1 NOAA Coral Reef Conservation Program, NOAA, Silver Spring, MD, 2 Fisheries, NOAA,
Galveston, TX
Over the last decade, reefs off southwest Puerto Rico and the associated islands have
experienced losses in live coral cover in excess of 50%, primarily due to the decline of M.
annularis and M. faveolata. These species were formerly the largest and most abundant corals
remaining on these reefs. Outbreaks of coral disease, especially white plague and yellow band
disease, affected over 50% of the colonies in some sites during the late 1990s; disease
prevalence declined between 2002-2004 and then increased immediately following a 2005 mass
bleaching event. These diseases have caused unprecedented rates of mortality, with cumulative
losses exacerbated by bleaching and parrotfish predation. In both species, a lack of recruitment
and only limited recovery through resheeting have been observed, and exposed skeletal surfaces
are being colonized by macroalgae, bioeroding sponges, hydrozoans, and other scleractinian
coral recruits (primarily Porites and Agaricia). Unlike acroporids, which have the potential for
rapid growth and recovery, M. annularis and M. faveolata are unlikely to recover in our
lifetimes and are being replaced by shorter-lived brooding species and other massive and plating
species with faster growth and higher recruitment rates. The impacts of these shifts on coral
community structure and reef fisheries are unknown. Approaches undertaken to recover
acroporids, such as propagation through fragmentation and grow-out of sexual recruits, are less
likely to work for M. annularis (complex) - species with slow rates of growth and limited
recruitment. To avoid a catastrophic and permanent shift in coral community composition,
research needs to be directed towards an improved understanding of the causes and impacts of
diseases and bleaching, and possible control mechanisms. Managers and policy makers must
take steps to mitigate environmental and anthropogenic stressors that increase the spread and
severity of disease.
7-4
The Future Of Coral Reefs in The Us Virgin Islands: Why acropora Palmata Is More
Likely To Recover Than montastraea Annularis Complex
Caroline ROGERS* 1 , Erinn MULLER 2 , Tony SPITZACK 1 , Jeff MILLER 3
1 US Geological Survey, St John, Virgin Islands (U.S.), 2 Florida Institute of Technology,
Melbourne, FL, 3 National Park Service, St John, Virgin Islands (U.S.)
The Caribbean bleaching/disease event that began in the summer of 2005 caused significant
mortality of the two most important reef-building corals in the US Virgin Islands (USVI),
Acropora palmata and Montastraea annularis complex (Macx). These corals characterize
the shallow and mid-depth zones of the islands’s reefs, and their ability to recover will define
the future seascape in the USVI. Research on A. palmata from 2003 to 2007 around St. John
documented disease prevalence ranging from 0 to 52% with high levels of white pox (and undescribed
diseases) and very low levels of white band disease that caused major losses 25-30
years ago. Over 94% of the white pox lesions healed at least partially. Acropora palmata
bleached for the first time in the USVI in 2005. Forty-five percent of 460 colonies from several
sites bleached, and 8% died. Bleached corals had greater disease mortality than unbleached.
Acropora palmata had high genotypic variation, and evidence of limited, recent sexual
recruitment. Survival of fragments ranged from 29 to 60%. Deeper reef zones dominated by
Macx showed greater coral bleaching and mortality (primarily from white plague) following the
record-high seawater temperatures in 2005. Over 98% of the Macx bleached, and ca. 90% of the
disease mortality was seen on Macx. Healing of disease lesions was not observed. Over the
next 50 to 100 years, A. palmata has a greater potential to recover than Macx because of its
higher growth rate, greater ability to colonize new areas through fragmentation, and lower
vulnerability to bleaching and disease. The future of these major reef-building corals and of
USVI reefs will depend also on the connectivity between these reef zones and sources of coral
larvae.
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