11th ICRS Abstract book - Nova Southeastern University

18.645
acropora Palmata Bleaching And Response Varied Across Benthic Zones At Buck
Island Reef National Monument (St. Croix, Usvi) During The 2005 Bleaching Event
Ian LUNDGREN* 1 , Zandy HILLIS-STARR 1
1 Buck Island Reef National Monument, National Park Service, Christiansted, Virgin
Islands (U.S.)
Corals at Buck Island Reef National Monument, located north of St. Croix, USVI,
experienced elevated sea surface temperatures in 2005, triggering a mass coral bleaching
event. By monitoring three sites before, during, and after the event, National Park Service
staff quantified the bleaching extent and the subsequent mortality of Acropora palmata.
Back reef and forereef sites experienced almost double the mortality that the reef shelf
site experienced. Additionally, the backreef site experienced bleaching impact first,
followed by the forereef site and the reef shelf. The loss of approximately 66% of live
Acropora palmata tissue on the back reef, 58% on the forereef, and 36% on the reef shelf
is the most devastating loss of Acropora palmata at Buck Island Reef National
Monument since the white-band disease outbreak of the 1970s. Given the recent listing of
this species under the Endangered Species Act, managers might find this information
useful to establish critical habitat, and to develop better monitoring protocol.
18.646
The Lingering Consequences Of A Mass Coral Bleaching Event On acropora
Palmata, At Buck Island Reef National Monument
Ian LUNDGREN* 1 , Zandy HILLIS-STARR 1
1
Buck Island Reef National Monument, National Park Service, Christiansted, Virgin
Islands (U.S.)
The realized impact of coral bleaching may be more extensive than previously thought.
Secondary effects may cause lingering impacts to Acropora palmata corals that
reverberate and cause continued mortality long after water temperatures cool. Elevated
sea surface temperatures at Buck Island Reef National Monument, located north of St.
Croix, USVI in 2005 triggered a mass coral bleaching event. National Park Service staff
recorded trends of Acropora palmata bleaching, mortality, disease, predation, and
physical breakage; before, during, and after the bleaching event. The pattern of these
variables suggests a succession of interactions initiated by bleaching. Generally,
bleaching was immediately followed by maximum breakage, then maximum disease,
then maximum predation. As a consequence of these synergistic impacts, mortality
remained consistently high for approximately one year after bleaching. These data
support recent research that demonstrates how the complex physiological effects from
coral bleaching can lead to considerable secondary ecological interactions within the reef
community.
Poster Mini-Symposium 18: Reef Status and Trends
18.647
Responses Of Coral Communities in The Florida Keys Following Multiple Stressor Events
in 1997-1998
Deborah SANTAVY* 1 , Erich MUELLER 2 , Lauri MACLAUGHLIN 3 , Esther PETERS 4 ,
Robert QUARLES 1 , Mace BARRON 1
1 US EPA, NHEERL, Gulf Ecology Division, Gulf Breeze, FL, 2 Perry Institute for Marine
Science, Jupiter, FL, 3 NOAA, Florida Keys National Marine Sanctuary, Key Largo, FL, 4 Tetra
Tech. Inc., Fairfax, VA
Coral reefs in South Florida have declined over the past 40 years and are projected to continue
to deteriorate due to persistent and intermittent exposure to multiple chronic stressors. This
study compared changes in the condition of mature colonies (≥ 10 cm) in two regions of South
Florida from 1998-2002, following exposure to several large scale disturbances including
Hurricane Georges and massive coral bleaching. Coral abundance, diversity measures, disease,
and bleaching prevalence on reefs near the remote off-shore islands of the Dry Tortugas were
compared to reefs near Key West characterized by higher population density and greater
anthropogenic influences. Initially in the spring of 1998, Key West and Dry Tortugas reefs were
similar in abundance, species richness, evenness, diversity, dominance, and prevalence of
disease at the locations sampled. Prevalence of coral bleaching and disease significantly
increased on reefs in both regions during the 1998 summer El Niño event, with Key West reefs
exhibiting the greatest prevalence and severity of coral bleaching and disease. Coral abundance
significantly decreased in 1998 in both regions, but remained lower only at Key West reefs
during the study. The greatest reef degradation occurred after increased sea temperatures led to
elevated coral bleaching and disease prior to Hurricane Georges. Acroporids declined near Key
West from 45 colonies/site (spring 1998) to ≤4 colonies (2002), whereas Dry Tortugas
acroporids initially declined but recovered within 5 years. Key West reefs presumptively lost
critical community properties such as regenerative capacity provided by the affected species, as
indicated by their inability to recover or return to original conditions. In contrast, Dry Tortugas
reefs resisted major changes and maintained coral community properties necessary to persist
and regenerate in the presence of similar disturbances.
18.648
Reproductive Failure in Acropora palmata, a Threatened Caribbean Coral
Dana E. WILLIAMS* 1,2 , Margaret W. MILLER 3 , K. Lindsey KRAMER 4 , Abel VALDIVIA 1,2
1 Cooperative Institute of Marine and Atmospheric Studies, University of Miami Rosenstiel
School of Marine and Atmospheric Science, Miami, FL, 2 Southeast Fisheries Science Center,
NOAA Fisheries, Miami, 3 Southeast Fisheries Science Center, NOAA Fisheries, Miami, FL,
4 Pacific Island Network, Inventory & Monitoring, National Park Service, Kona, HI
Acropora palmata is thought to be well adapted to survive and even proliferate through
fragmentation during physical disturbances such as moderate intensity hurricanes. Since 2004,
approximately 200 randomly selected tagged colonies of A. palmata and 2250m2 of reef
benthos have been monitored in fifteen fixed study plots in the upper Florida Keys (USA).
Between July and October 2005, 4 hurricanes passed by this region, producing maximum wind
speeds on the reef tract of 44 to 65kts. Surveys of study plots following the storms documented
an average loss of more than half of the estimated live tissue area since the initial survey in
2004. The percentage of the population classified as ‘branching’ colonies decreased from 69%
to 39% while ‘remnant’-type colonies (isolated patches of tissue on standing skeleton) increased
from 10% to 33%. Although some lost branches were present as loose fragments, within 3
weeks after Hurricane Dennis more than 70% of the 380 fragments observed in the study plots
were dead or rapidly losing tissue. To date, only 27 fragments attached to the substrate, forming
successful asexual recruits. Moreover, of the 18 new small encrusting colonies that were
observed in the study plots, only 2 were not attributable to asexual origin (i.e. remnant tissue
patches from colonies or fragments previously observed) and therefore are possible sexual
recruits. In sum, only 2 potential sexual recruits have appeared in the 3 year span of this study
and the 2005 hurricane season resulted in a substantial loss of A. palmata from a combination of
physical removal and disease-like tissue mortality and few asexual recruits. Furthermore the
asexual and sexual fecundity of the remaining population is compromised for the near future
due to lack of branches (i.e. ‘asexual fecundity’) and overall loss of live tissue.
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