Life Sciences Commons^™

Rapid Population Decline Of The Pillar Coral Dendrogyra Cylindrus Along The Florida Reef Tract, Karen L. Neely, Cynthia L. Lewis, Kathleen S. Lunz, Lystina Kabay

Marine & Environmental Sciences Faculty Articles

Coral reefs worldwide are in a state of decline, but the population status and impacts of stressors for rare species are generally not well documented using broad-scale monitoring protocols. We fate-tracked all known colonies of the pillar coral, Dendrogyra cylindrus, on the Florida Reef Tract (FRT) from 2013 to 2020 to assess population condition and trend, and to document the relative impacts of chronic and acute stressors. Large average colony size, an absence of juveniles, and large geographic distances between genotypes suggest that the Florida D. cylindrus population has been reproductively extinct for decades. During the study period, low-intensity …

Survivorship And Growth In Staghorn Coral (Acropora Cervicornis) Outplanting Projects In The Florida Keys National Marine Sanctuary, Matt Ware, Eliza N. Garfield, Ken Nedimyer, Jessica Levy, Les Kaufman, William F. Precht, R. Scott Winters, Steven Miller

Marine & Environmental Sciences Faculty Articles

Significant population declines in Acropora cervicornis and A. palmata began in the 1970s and now exceed over 90%. The losses were caused by a combination of coral disease and bleaching, with possible contributions from other stressors, including pollution and predation. Reproduction in the wild by fragment regeneration and sexual recruitment is inadequate to offset population declines. Starting in 2007, the Coral Restoration Foundation™ evaluated the feasibility of outplanting A. cervicornis colonies to reefs in the Florida Keys to restore populations at sites where the species was previously abundant. Reported here are the results of 20 coral outplanting projects …

Modulation Of Light-Enhancement To Symbiotic Algae By Light-Scattering In Corals And Evolutionary Trends In Bleaching, Luisa A. Marcelino, Mark W. Westneat, Valentina P. Stoyneva, Jillian Henss, Jeremy Rogers, Andrew J. Radosevich, Vladimir Turzhitsky, Margaret Siple, Andrew Fang, Timothy D. Swain, Jennifer Fung, Vadim Backman

Marine & Environmental Sciences Faculty Articles

Calcium carbonate skeletons of scleractinian corals amplify light availability to their algal symbionts by diffuse scattering, optimizing photosynthetic energy acquisition. However, the mechanism of scattering and its role in coral evolution and dissolution of algal symbioses during “bleaching” events are largely unknown. Here we show that differences in skeletal fractal architecture at nano/micro-lengthscales within 96 coral taxa result in an 8-fold variation in light-scattering and considerably alter the algal light environment. We identified a continuum of properties that fall between two extremes: (1) corals with low skeletal fractality that are efficient at transporting and redistributing light throughout the colony with …

Human Impact On Atolls Leads To Coral Loss And Community Homogenisation: A Modeling Study, Bernhard Riegl, Charles R. C. Sheppard, Samuel J. Purkis

Marine & Environmental Sciences Faculty Articles

We explore impacts on pristine atolls subjected to anthropogenic near-field (human habitation) and far-field (climate and environmental change) pressure. Using literature data of human impacts on reefs, we parameterize forecast models to evaluate trajectories in coral cover under impact scenarios that primarily act via recruitment and increased mortality of larger corals. From surveys across the Chagos, we investigate the regeneration dynamics of coral populations distant from human habitation after natural disturbances. Using a size-based mathematical model based on a time-series of coral community and population data from 1999–2006, we provide hind- and forecast data for coral population dynamics within lagoons …

Red Sea Coral Reef Trajectories Over 2 Decades Suggest Increasing Community Homogenization And Decline In Coral Size, Bernhard Riegl, Andrew W. Bruckner, Gwilym Rowlands, Samuel J. Purkis, Philip Renaud

Marine & Environmental Sciences Faculty Articles

Three independent line intercept transect surveys on northern Red Sea reef slopes conducted in 1988/9 and 1997/8 in Egypt and from 2006–9 in Saudi Arabia were used to compare community patterns and coral size. Coral communities showed scale-dependent variability, highest at fine spatial and taxonomic scale (species-specific within and among reef patterns). At coarser scale (generic pattern across regions), patterns were more uniform (regionally consistent generic dominance on differently exposed reef slopes and at different depths). Neither fine- nor coarse-scale patterns aligned along the sampled 1700 km latitudinal gradient. Thus, a latitudinal gradient that had been described earlier from comparable …

Present Limits To Heat-Adaptability In Corals And Population-Level Responses To Climate Extremes, Bernhard Riegl, Samuel J. Purkis, Ashraf S. Al-Cibahy, Mohammed A. Abdel-Moati, Ove Hoegh-Guldberg

Marine & Environmental Sciences Faculty Articles

Climate change scenarios suggest an increase in tropical ocean temperature by 1–3°C by 2099, potentially killing many coral reefs. But Arabian/Persian Gulf corals already exist in this future thermal environment predicted for most tropical reefs and survived severe bleaching in 2010, one of the hottest years on record. Exposure to 33–35°C was on average twice as long as in non-bleaching years. Gulf corals bleached after exposure to temperatures above 34°C for a total of 8 weeks of which 3 weeks were above 35°C. This is more heat than any other corals can survive, providing an insight into the present limits …

Severe 2010 Cold-Water Event Caused Unprecedented Mortality To Corals Of The Florida Reef Tract And Reversed Previous Survivorship Patterns, Diego Lirman, Stephanie Schopmeyer, Derek Manzello, Lewis J. Gramer, William F. Precht, Frank E. Muller-Karger, Kenneth Banks, Brian Barnes, Erich Bartels, Amanda Bourque, James Byrne, Scott Donahue, Janice Duquesnel, Louis Fisher, David S. Gilliam, James C. Hendee, Meaghan E. Johnson, Kerry Maxwell, Erin Mcdevitt, Jamie Monty, Digna Rueda, Rob Ruzicka, Sara Thanner

Marine & Environmental Sciences Faculty Articles

Background

Coral reefs are facing increasing pressure from natural and anthropogenic stressors that have already caused significant worldwide declines. In January 2010, coral reefs of Florida, United States, were impacted by an extreme cold-water anomaly that exposed corals to temperatures well below their reported thresholds (16°C), causing rapid coral mortality unprecedented in spatial extent and severity.

Methodology/Principal Findings

Reef surveys were conducted from Martin County to the Lower Florida Keys within weeks of the anomaly. The impacts recorded were catastrophic and exceeded those of any previous disturbances in the region. Coral mortality patterns were directly correlated to in-situ and satellite-derived …

Caribbean Corals In Crisis: Record Thermal Stress, Bleaching, And Mortality In 2005, C. Mark Eakin, Jessica A. Morgan, Scott F. Heron, Tyler B. Smith, Gang Liu, Lorenzo Alvarez-Filip, Bart J. Baca, Erich Bartels, Carolina Bastidas, Claude Bouchon, Marilyn Brandt, Andrew W. Bruckner, Lucy Bunkley-Williams, Andrew Cameron, Billy D. Causey, Mark Chiappone, Tyler R. L. Christensen, M. James C. Crabbe, Owen Day, Elena De La Guardia, Guillermo Diaz-Pulido, Daniel Diresta, Diego L. Gil-Agudelo, David S. Gilliam, Robert N. Ginsburg, Shannon Gore, Hector M. Guzman, James C. Hendee, Edwin A. Hernandez-Delgado, Ellen Husain, Christopher F. G. Jeffrey, Ross J. Jones, Eric Jordan-Dahlgren, Les S. Kaufman, David I. Kline, Philip A. Kramer, Judith C. Lang, Diego Lirman, Jennie Mallela, Carrie Manfrino, Jean-Philippe Marechal, Ken Marks, Jennifer Mihaly, W. Jeff Miller, Erich M. Mueller, Erinn M. Muller, Carlos A. Orozco Toro, Hazel A. Oxenford, Daniel Ponce-Taylor, Norman Quinn, Kim B. Ritchie, Sebastian Rodriguez, Alberto Rodriguez Ramirez, Sandra Romano, Jameal F. Samhouri, Juan A. Sanchez, George P. Schmahl, Burton V. Shank, William J. Skirving, Sascha C. C. Steiner, Estrella Villamizar, Sheila M. Walsh, Cory Walter, Ernesto Weil, Ernest H. Williams, Kimberly Woody Roberson, Yusri Yusuf

Marine & Environmental Sciences Faculty Articles

Background: The rising temperature of the world’s oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin.

Methodology/Principal Findings: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers’ field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior …

Tissue Damage In Scleractinian And Alcyonacean Corals Due To Experimental Exposure To Sedimentation, Bernhard Riegl, Jonathan P. Bloomer

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Four South African scleractinian corals (Favia favus, Favites pentagona, Platygyra daedalea and Gyrosmilia interrupta) and four alcyonacean corals (Lobophytum depressum, Lobophytum venustum, Sinularia dura and Sinularia leptoclados) were experimentally exposed to high sedimentation conditions in the laboratory during a period of six weeks. Experimental sedimentation corresponded to the highest measured sedimentation levels on South African coral reefs, being 200 mg cm-2h-l. Corals were monitored for tissue necroses and bleaching during the course of the experiment and histological sections were prepared after the termination of the experiment. During the experiment, tissue necroses appeared earlier and more frequently in alcyonacea than in …