The 11th International Coral Reef Symposium is in conference now at Ft. Lauderdale, FL. Here are some interesting abstracts of what is being presented:
African Dust Poses Threat to Coral Reefs and Human Health: Contaminants carried with African dust to the Caribbean and the Americas may be a threat to marine organisms and humans, according to preliminary results of a new study by researchers with the U.S. Geological Survey, Oregon State University, and the University of the West Indies. The scientists compared contaminant levels in sources of African dust and downwind regions. Of the more than 100 persistent organic pollutants screened for in the samples, including banned and common-use pesticides, six pesticides (chlorpyrifos, dacthal, endosulfans, hexachlorobenzene, chlordane, and trifluralin) were detected in samples from all sites. Concentrations were significantly higher in Mali. DDE (a breakdown product of DDT) was also identified in Mali, U.S. Virgin Islands, and Trinidad samples. To date, DDT and carcinogenic dioxins and furans have been detected only in samples from Mali. Many of the identified contaminants are thought to be toxic to corals and other marine organisms and can interfere with reproduction, fertilization, or immune function. For more information, contact Virginia Garrison at 727-803-8747, ext. 3061 or ginger_garrison@usgs.gov.
The Good, the Bad, and the Smelly: How do Coral Larvae Know Where to Settle? How algal species maintain dominance in degraded reef habitats is a critical question for reef resource managers. Some common reef algae, but not all, use chemical defenses to inhibit grazing by Caribbean reef fishes and the sea urchin Diadema antillarum. These chemical defenses may also influence competitive interactions between algae and corals. In this study, researchers found that chemical extracts of certain algal species could be detected (i.e., "smelled") by coral larvae, causing them to avoid settling in the area. However, not all algae are bad; some coralline (calcified) algae may act as facilitators for coral settlement. The research also showed that individual species of corals had the highest settlement in response to different species of coralline algae, indicating that higher coralline algal diversity could potentially enhance coral recruit diversity. For more information, contact Raphael Ritson-Williams at 772-538-0495, williams@si.edu or Ilsa Kuffner at 727-492-3886, ikuffner@usgs.gov.
The Origin of Aspergillus Sydowii, a Common Disease of Caribbean Corals: Coral reefs are increasingly suffering outbreaks of disease, causing dramatic declines in population abundance and diversity. One of the best-characterized coral diseases is aspergillosis, caused by the fungus Aspergillus sydowii. A. sydowii is a globally distributed fungus commonly found in soil, so its presence in marine systems raises questions about its origin. By using microsatellite markers, researchers analyzed the population structure of A. sydowii from diseased sea fans, diseased humans and environmental sources worldwide. The results indicate that A. sydowii forms a single global population, with low to moderate genetic differences between the disease found in sea fans and the same fungus from environmental sources. Past researchers have suggested that A. sydowii originates from African dust blown into the Caribbean, and have identified Aspergillus from dust samples, although often only to the genus level. To test this, researchers isolated fungi from dust samples collected in Mali and St. Croix. Although a diversity of fungi was documented from African dust, including seven species of Aspergillus, none of the samples contained A. sydowii. Taken in conjunction with recent molecular evidence suggesting lack of a single point source of the fungus, this research suggests that there are likely multiple sources and introductions of this pathogen into marine systems. For more information contact Krystal Rypien at 858-534-3196, krypien@ucsd.edu or Virginia Garrison at 727-803-8747, ext. 3061 or ginger_garrison@usgs.gov.
Disease Characteristics of Montipora White Syndrome in Kaneohe Bay, Oahu, Hawaii: Coral disease is emerging as a problem in the Indo-Pacific yet little is known about the ecology of these diseases or factors that may be affecting disease levels. Montipora white syndrome (MWS) is a coral disease resulting in tissue loss that was identified in Kaneohe Bay, Oahu, Hawaii, in 2004 but that has been documented throughout the Hawaiian archipelago. Kaneohe Bay provided a model system to examine the ecology and pathogenesis of this disease in detail. MWS was found in all seasons of the year, as well as all regions of Kaneohe Bay but prevalence was highest in south Kaneohe Bay. Fifty-four out of 57 tagged coral colonies infected with this disease experienced progressive tissue loss ranging from 1 percent of the colony to complete mortality within one year. One-third of the colonies lost more than 90 percent of their tissues resulting in partial to complete colony collapse within one year. Researchers found that MWS stopped and re-started on individual colonies and that multiple potential causes were seen when lesions were examined under the microscope. In addition, orange morphs of Montipora capitata are more susceptible to the disease than red morphs. For more information, contact Greta Aeby at 808 386-4784, greta@hawaii.edu or Thierry Work at 808-792-9520, Thierry_work@usgs.gov.
African Dust Poses Threat to Coral Reefs and Human Health: Contaminants carried with African dust to the Caribbean and the Americas may be a threat to marine organisms and humans, according to preliminary results of a new study by researchers with the U.S. Geological Survey, Oregon State University, and the University of the West Indies. The scientists compared contaminant levels in sources of African dust and downwind regions. Of the more than 100 persistent organic pollutants screened for in the samples, including banned and common-use pesticides, six pesticides (chlorpyrifos, dacthal, endosulfans, hexachlorobenzene, chlordane, and trifluralin) were detected in samples from all sites. Concentrations were significantly higher in Mali. DDE (a breakdown product of DDT) was also identified in Mali, U.S. Virgin Islands, and Trinidad samples. To date, DDT and carcinogenic dioxins and furans have been detected only in samples from Mali. Many of the identified contaminants are thought to be toxic to corals and other marine organisms and can interfere with reproduction, fertilization, or immune function. For more information, contact Virginia Garrison at 727-803-8747, ext. 3061 or ginger_garrison@usgs.gov.
The Good, the Bad, and the Smelly: How do Coral Larvae Know Where to Settle? How algal species maintain dominance in degraded reef habitats is a critical question for reef resource managers. Some common reef algae, but not all, use chemical defenses to inhibit grazing by Caribbean reef fishes and the sea urchin Diadema antillarum. These chemical defenses may also influence competitive interactions between algae and corals. In this study, researchers found that chemical extracts of certain algal species could be detected (i.e., "smelled") by coral larvae, causing them to avoid settling in the area. However, not all algae are bad; some coralline (calcified) algae may act as facilitators for coral settlement. The research also showed that individual species of corals had the highest settlement in response to different species of coralline algae, indicating that higher coralline algal diversity could potentially enhance coral recruit diversity. For more information, contact Raphael Ritson-Williams at 772-538-0495, williams@si.edu or Ilsa Kuffner at 727-492-3886, ikuffner@usgs.gov.
The Origin of Aspergillus Sydowii, a Common Disease of Caribbean Corals: Coral reefs are increasingly suffering outbreaks of disease, causing dramatic declines in population abundance and diversity. One of the best-characterized coral diseases is aspergillosis, caused by the fungus Aspergillus sydowii. A. sydowii is a globally distributed fungus commonly found in soil, so its presence in marine systems raises questions about its origin. By using microsatellite markers, researchers analyzed the population structure of A. sydowii from diseased sea fans, diseased humans and environmental sources worldwide. The results indicate that A. sydowii forms a single global population, with low to moderate genetic differences between the disease found in sea fans and the same fungus from environmental sources. Past researchers have suggested that A. sydowii originates from African dust blown into the Caribbean, and have identified Aspergillus from dust samples, although often only to the genus level. To test this, researchers isolated fungi from dust samples collected in Mali and St. Croix. Although a diversity of fungi was documented from African dust, including seven species of Aspergillus, none of the samples contained A. sydowii. Taken in conjunction with recent molecular evidence suggesting lack of a single point source of the fungus, this research suggests that there are likely multiple sources and introductions of this pathogen into marine systems. For more information contact Krystal Rypien at 858-534-3196, krypien@ucsd.edu or Virginia Garrison at 727-803-8747, ext. 3061 or ginger_garrison@usgs.gov.
Disease Characteristics of Montipora White Syndrome in Kaneohe Bay, Oahu, Hawaii: Coral disease is emerging as a problem in the Indo-Pacific yet little is known about the ecology of these diseases or factors that may be affecting disease levels. Montipora white syndrome (MWS) is a coral disease resulting in tissue loss that was identified in Kaneohe Bay, Oahu, Hawaii, in 2004 but that has been documented throughout the Hawaiian archipelago. Kaneohe Bay provided a model system to examine the ecology and pathogenesis of this disease in detail. MWS was found in all seasons of the year, as well as all regions of Kaneohe Bay but prevalence was highest in south Kaneohe Bay. Fifty-four out of 57 tagged coral colonies infected with this disease experienced progressive tissue loss ranging from 1 percent of the colony to complete mortality within one year. One-third of the colonies lost more than 90 percent of their tissues resulting in partial to complete colony collapse within one year. Researchers found that MWS stopped and re-started on individual colonies and that multiple potential causes were seen when lesions were examined under the microscope. In addition, orange morphs of Montipora capitata are more susceptible to the disease than red morphs. For more information, contact Greta Aeby at 808 386-4784, greta@hawaii.edu or Thierry Work at 808-792-9520, Thierry_work@usgs.gov.
