Category Archives: coral
Ecotoxicology: Toxicological effects of the sunscreen UV filter, benzophenone-2, on planulae and in vitro cells of the coral, *Stylophora pistillata* by C. A. Downs • Esti Kramarsky-Winter • John E. Fauth • Roee Segal •Omri Bronstein • Rina Jeger • Yona Lichtenfeld • Cheryl M. Woodley • Paul Pennington • Ariel Kushmaro • Yossi Loya
The article is in the journal Ecotoxicology. A link to the article can be
found at http://link.springer.com/article/10.1007/s10646-013-1161-y
Accepted: 7 December 2013
Abstract Benzophenone-2 (BP-2) is an additive to personal-care products and commercial solutions that protects against the damaging effects of ultraviolet light. BP-2 is an ‘‘emerging contaminant of concern’’ that is often released as a pollutant through municipal and boat/ship wastewater discharges and landfill leachates, as well as through residential septic
fields and unmanaged cesspits. AlthoughBP-2may be a contaminant on coral reefs, its environmental toxicity to reefs is unknown. This poses a potential management issue, since BP-2 is a known endocrine disruptor as well as a weak genotoxicant. We examined the effects of BP-2 on the larval form (planula) of the coral, Stylophora pistillata, as well as its toxicity to in vitro coral cells. BP-2 is a photo-toxicant; adverse effects are exacerbated in the light versus in darkness. Whether in darkness or light,
BP-2 induced coral planulae to transformfromamotile planktonic state to a deformed, sessile condition. Planulae exhibited an increasing rate of coral bleaching in response to increasing concentrations of BP-2. BP-2 is a genotoxicant to corals, exhibiting a strong positive relationship between DNA-AP lesions and increasing BP-2 concentrations. BP-2 exposure in the
light induced extensive necrosis in both the epidermis and gastrodermis. In contrast, BP-2 exposure in darkness induced autophagy and autophagic cell death. The LC50 of BP-2 in the light for an 8 and 24 h exposure was 120 and 165 parts per billion (ppb), respectively. The LC50s for BP-2 in darkness for the same time points were 144 and 548 ppb. Deformity EC20 levels (24
h) were 246 parts per trillion in the light and 9.6 ppb in darkness.
Annual Reviews.org: Climate change influences on marine infectious disease: implications for management and society by Burge, Eakin, Friedman, Froelich, Hershberger, Hoffman, Petes, Preager, Weil, Willis, Ford and Harvell.
2014. *Annual Reviews in Marine Science*. 6: 249-277
Available online:
http://www.annualreviews.org/doi/abs/10.1146/annurev-marine-010213-135029
Climate Change Influences on Marine Infectious Diseases: Implications for Management and Society
Annual Review of Marine Science
Vol. 6: 249-277 (Volume publication date January 2014)
First published online as a Review in Advance on June 27, 2013
DOI: 10.1146/annurev-marine-010213-135029
Colleen A. Burge,1 C. Mark Eakin, Carolyn S. Friedman, Brett Froelich, Paul K. Hershberger, Eileen E. Hofmann, Laura E. Petes, Katherine C. Prager, Ernesto Weil, Bette L. Willis, Susan E. Ford, and C. Drew Harvell1
1Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853; email: cab433@cornell.edu, cdh5@cornell.edu*
ABSTRACT
Infectious diseases are common in marine environments, but the effects of a changing climate on marine pathogens are not well understood. Here we review current knowledge about how the climate drives host-pathogen interactions and infectious disease outbreaks. Climate-related impacts on marine diseases are being documented in corals, shellfish, finfish, and humans; these impacts are less clearly linked for other organisms. Oceans and people are inextricably linked, and marine diseases can both directly and indirectly affect human health, livelihoods, and well-being. We recommend an adaptive management approach to better increase the resilience of ocean systems vulnerable to marine diseases in a changing climate. Land-based management methods of quarantining, culling, and vaccinating are not successful in the ocean; therefore, forecasting conditions that lead to outbreaks and designing tools/approaches to influence these conditions may be the best way to manage marine disease.
Special thanks to Coral-list post by Colleen Burge
PLOS ONE: Hyperspectral Sensing of Disease Stress in the Caribbean Reef-Building Coral, Orbicella faveolata – Perspectives for the Field of Coral Disease Monitoring by David A. Anderson, Roy A. Armstrong, Ernesto Weil
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0081478
Published: December 04, 2013
DOI: 10.1371/journal.pone.0081478
Abstract
The effectiveness of management plans developed for responding to coral disease outbreaks is limited due to the lack of rapid methods of disease diagnosis. In order to fulfill current management guidelines for responding to coral disease outbreaks, alternative methods that significantly reduce response time must be developed. Hyperspectral sensing has been used by various groups to characterize the spectral signatures unique to asymptomatic and bleached corals. The 2010 combined bleaching and Caribbean yellow band disease outbreak in Puerto Rico provided a unique opportunity to investigate the spectral signatures associated with bleached and Caribbean yellow band-diseased colonies of Orbicella faveolata for the first time. Using derivative and cluster analyses of hyperspectral reflectance data, the present study demonstrates the proof of concept that spectral signatures can be used to differentiate between coral disease states. This method enhanced predominant visual methods of diagnosis by distinguishing between different asymptomatic conditions that are identical in field observations and photographic records. The ability to identify disease-affected tissue before lesions become visible could greatly reduce response times to coral disease outbreaks in monitoring efforts. Finally, spectral signatures associated with the poorly understood Caribbean yellow band disease are presented to guide future research on the role of pigments in the etiology.
Oregon State University: Large study shows pollution impact on coral reefs — and offers solution
Contact: Rebecca Vega-Thurber
Rebecca.vega-thurber@oregonstate.edu
541-737-1851
IMAGE: Diver Andrew Schantz of Florida International University studies the effect of pollution on corals in the Florida Keys.
Click here for more information.
CORVALLIS, Ore. – One of the largest and longest experiments ever done to test the impact of nutrient loading on coral reefs today confirmed what scientists have long suspected – that this type of pollution from sewage, agricultural practices or other sources can lead to coral disease and bleaching.
A three-year, controlled exposure of corals to elevated levels of nitrogen and phosphorus at a study site in the Florida Keys, done from 2009-12, showed that the prevalence of disease doubled and the amount of coral bleaching, an early sign of stress, more than tripled.
However, the study also found that once the injection of pollutants was stopped, the corals were able to recover in a surprisingly short time.
“We were shocked to see the rapid increase in disease and bleaching from a level of pollution that’s fairly common in areas affected by sewage discharge, or fertilizers from agricultural or urban use,” said Rebecca Vega-Thurber, an assistant professor in the College of Science at Oregon State University.
“But what was even more surprising is that corals were able to make a strong recovery within 10 months after the nutrient enrichment was stopped,” Vega-Thurber said. “The problems disappeared. This provides real evidence that not only can nutrient overload cause coral problems, but programs to reduce or eliminate this pollution should help restore coral health. This is actually very good news.”
The findings were published today in Global Change Biology, and offer a glimmer of hope for addressing at least some of the problems that have crippled coral reefs around the world. In the Caribbean Sea, more than 80 percent of the corals have disappeared in recent decades. These reefs, which host thousands of species of fish and other marine life, are a major component of biodiversity in the tropics.
IMAGE: This coral, which was part of a scientific study, is bleached as a result of exposure to elevated levels of nitrogen and phosphorus.
Click here for more information.
Researchers have observed for years the decline in coral reef health where sewage outflows or use of fertilizers, in either urban or agricultural areas, have caused an increase in the loading of nutrients such as nitrogen and phosphorus. But until now almost no large, long-term experiments have actually been done to pin down the impact of nutrient overloads and separate them from other possible causes of coral reef decline.
This research examined the effect of nutrient pollution on more than 1,200 corals in study plots near Key Largo, Fla., for signs of coral disease and bleaching, and removed other factors such as water depth, salinity or temperature that have complicated some previous surveys. Following regular injections of nutrients at the study sites, levels of coral disease and bleaching surged.
One disease that was particularly common was “dark spot syndrome,” found on about 50 percent of diseased individual corals. But researchers also noted that within one year after nutrient injections were stopped at the study site, the level of dark spot syndrome had receded to the same level as control study plots in which no nutrients had been injected.
The exact mechanism by which nutrient overload can affect corals is still unproven, researchers say, although there are theories. The nutrients may add pathogens, may provide the nutrients needed for existing pathogens to grow, may be directly toxic to corals and make them more vulnerable to pathogens – or some combination of these factors.
“A combination of increased stress and a higher level of pathogens is probably the mechanism that affects coral health,” Vega-Thurber said. “What’s exciting about this research is the clear experimental evidence that stopping the pollution can lead to coral recovery. A lot of people have been hoping for some news like this.
“Some of the corals left in the world are actually among the species that are most hardy,” she said. “The others are already dead. We’re desperately trying to save what’s left, and cleaning up the water may be one mechanism that has the most promise.”
VIDEO: This is an interview with Rebecca Vega-Thurber about new findings in a coral reef study off the Florida Keys.
Click here for more information.
Nutrient overloads can increase disease prevalence or severity on many organisms, including plants, amphibians and fish. They’ve also long been suspected in coral reef problems, along with other factors such as temperature stress, reduced fish abundance, increasing human population, and other concerns.
However, unlike factors such as global warming or human population growth, nutrient loading is something that might be more easily addressed on at least a local basis, Vega-Thurber said. Improved sewage treatment or best-management practices to minimize fertilizer runoff from agricultural or urban use might offer practical approaches to mitigate some coral reef declines, she said.
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Collaborators on this research included Florida International University and the University of Florida. The work was supported by the National Science Foundation and Florida International University.
Editor’s Note: Digital images are available to illustrate this research:
Diver at study site: http://bit.ly/16bCW7w
Bleached coral: http://bit.ly/1bzLpjm
Nutrient dispenser: http://bit.ly/16gC8cp
A package of video interviews and associated B-roll, including underwater video, is also available for downloading in high resolution format:
Underwater b-roll:
http://oregonstate.edu/dept/ncs/media/rebecca-vega-thurber-underwater-b-roll-news-release.mov
Package interview with Dr. Rebecca Vega Thurber:
http://oregonstate.edu/dept/ncs/media/rebecca-vega-thurber-package-news-release.mov
Dr. Rebecca Vega Thurber Interview:
http://oregonstate.edu/dept/ncs/media/rebecca-vega-thurber-interview-news-release.mov
Laboratory b-roll:
http://oregonstate.edu/dept/ncs/media/rebecca-vega-thurber-b-roll-news-release.mov
Rebecca Vega Thurber Interview (audio only):