Disease Resistanct in Corals - CORNELL UNIVERSITY

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
212	2150	1070	100%

Progress 10/01/08 to 09/30/09

Outputs
OUTPUTS: The objectives of this project included determination of: 1) the origin and spread of the aspergillosis outbreak in sea fans; 2) factors involved in coral resistance to disease; 3) environmental facilitators in the aspergillosis outbreak; 4) demographic and spatial determinants of infection risk; and 5) host-based modeling of disease dynamics. Through the course of this NSF project we have incorporated molecular methods to address several questions about host and pathogen populations dynamics. We developed microsatellite markers to investigate the source of the Aspergillus sydowii in the marine environment and to examine the relationship between seafans, their algal symbiont, and spatial features such as oceanographic currents. Another central focus of our laboratory studies has been on the chemical and physiological aspects of coral immune responses to better understand how infection is established, how and where it propagates within a colony, and whether colonies can recover from infection. These studies have provided critical data for the development of a host-based model for sea fan disease dynamics. We have developed and implemented molecular methods, in vitro assays and histological techniques to test our primary hypothesis that some environmental facilitators compromise coral immunity. After establishing a repertoire of relevant assays, we investigated the timing, control and specificity of these immunological responses and looked at these measures over geographical, temperature and water quality gradients through laboratory experiments and our continued long-term monitoring efforts. These ongoing surveys in Mexico and Florida have provided valuable knowledge about coral population and disease dynamics that have contributed to demographic modeling approaches and to enhanced monitoring efforts. During the course of this funding, we encountered one of the largest temperature anomalies recorded in the Caribbean. This exceptionally warm summer of 2005 provided unique opportunities to investigate the effects of temperature on seafan disease and resistance in natural populations. Our EID project interfaces with a World Bank Program on Coral Diseases and Coral Reef Sustainability, through which we ran several international workshops that provided extensive training and networking opportunities. Our studies of seafan disease resistance also led to the development of a teaching module entitled: How Corals Fight Germs that was used as a session at Ithaca Sciencenter Camp for 18 1-4 graders. The Harvell lab is also featured on Cornell's Cybertower online alumni education series. Our efforts based on this funding have resulted in more than 60 publications including several describing our predictive models that culminated from these studies. In addition to the papers listed below, we have several other manuscripts in the final stages of preparation for submission. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our successful completion of the objectives described above has significantly advanced our understanding of host and environmental factors that influence marine disease dynamics. These insights resulted in several predictive mathematical models for disease that will be applicable to a wide range of systems. Our studies have given us better tools and techniques to examine coral disease and we have actively applied these tools to new species of corals that are critical to reef sustainability and that are highly sensitive to climate warming. The conclusions from our molecular and biochemical work on this project will likely impact the ways in which we manage coral disease. We have an ongoing dialog with several marine managers and conservation scientists who can use this information in developing management strategies. The scientists involved in these studies have made important contributions to multiple fields and were key participants in the 2008 International Coral Reef Symposium. Dr. Harvell was a plenary speaker at this large, well-attended gathering of 4,000 coral scientists, which drew considerable media attention to critical global reef health issues.

Publications

Andras, J.P., Kirk, N.L., Coffroth, M.A., and Harvell, C.D. 2009. Isolation and characterization of microsatellite loci in Symbiodinium B1/B184, the dinoflagellate symbiont of the Caribbean sea fan coral, Gorgonia ventalina. Molecular Ecology Resources 9(3):989-993.
Andras, J., Kirk, N., and Harvell, C.D. 2009. Population structure of Symbiodinium sp. associated with the common sea fan, Gorgonia ventalina, in the Florida Keys across distance, depth, and time. Marine Biology 156(8): 1609-1623.
Andras, J. and Rypien, K. 2009. Isolation and characterization of microsatellite loci in the Caribbean sea fan coral, Gorgonia ventalina. Marine Ecology 9:1036-1038.
Harvell, C.D., Altizer, S., Cattadori, I.M., Harrington, L., and Weil, E. 2009. Climate change and Wildlife disease: When does the host matter most Ecology 90(4):912-920.
Page, C.A., Baker, D.M., Harvell, C.D., Golbuu, Y., Raymundo, L., Neale, S.J., Rosell, K.B., Rypien, K.R., Andras, J.P., and Willis, B.L. 2009. Do marine protected areas influence disease prevalence Diseases of Aquatic Organisms. (In Press).
Rees, M. and Ellner, S.P. 2009. Integral projection models for populations in temporally varying environments. Ecological Monographs 79:575-594.
Rivest, E., Baker, D.M., Rypien, K.L., and Harvell, C.D. 2009. Nitrogen source preference of Aspergillus sydowii, an infective agent associated with aspergillosis of sea fan corals. Limnology & Oceanography. (In Press).
Rypien, K.L. and Baker, D.M. 2009. Isotopic labeling and antifungal resistance as tracers of gut passage of the sea fan pathogen Aspergillus sydowii. Diseases of Aquatic Organisms, 86:1-7.

Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: This last year focused on bringing several of our efforts to publication including our predictive models of sea fan disease dynamics, our molecular analysis of the Aspergillus origins, and our investigations of environmental effects on coral cellular immunity. We have also evaluated our data from the 2005 temperature anomaly in preparation for publication. In the last year, we looked at measures of immunity in corals over geographical, temperature and water quality gradients through laboratory experiments and our continued long-term monitoring efforts. We have focused effort in the last year to developing additional measures of coral immunity and on identifying additional immune pathways for future investigations. In order to examine the timing of cellular immune responses in sea fans, we exposed corals to fungus, disease tissue grafts and Fire Coral (an irritant). Sea fans mounted a cellular response to the fungus and diseased grafts within the first 24 to 48 hours of exposure but M. alcicornis did not induce a significant response. These results indicate that sea fans mount a cellular response prior to the generalized tissue purpling commonly observed surrounding diseased tissue suggesting that this cellular response may have a role in quelling early pathogen colonization. We also examined this cellular response to disease grafts and Fire Coral in field experiments in Puerto Rico. Samples were collected for histological analysis as well as immune assays to determine whether other components of innate immunity may be coupled with cellular response. The data analysis is currently in progress. We have also been applying our assays of immune responses to a wider range of corals, including the reef building coral Montastrea faveolata. We observed that this species experienced high mortality from yellow band disease during the 2005 bleaching event. Some immune factors, like lysozyme and antibacterial activity, were induced throughout infected corals but tended to be suppressed in bleached corals. Other immune factors, such as prophenoloxidase, showed an opposite trend with elevated levels in the bleached corals collected in 2005. These results demonstrate that some components of immunity respond to natural temperature stress as predicted and are suppressed, while others are actually activated by elevated temperatures, suggesting a general stress response or resilience to a changing environment. To continue this analysis, we ran an experiment in a closed aquaria system using healthy colonies of M. faveolata to examine the effects of temperature stress on immunocompetence. We are currently analyzing these samples. During this time we accomplished several additional goals, we explored several additional reef sites in Puerto Rico as future experimental settings and we performed several smaller scale pilot studies examining the effects of pathogen elicitors and signaling molecules on coral immunity. In addition to the publications indicated below, the results of this study have been disseminated through scientific meetings, workshops and annual meetings of the PIs on this project. Several other manuscripts are also in preparation. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This project has significantly advanced our understanding of host and environmental factors that influence marine disease dynamics. These insights have resulted in an additional predictive model in the last year that examines the relationship of host demographics and immune success. Our studies have given us better tools and techniques to examine coral disease and we have actively applied these tools to new species of corals that are critical to reef sustainability and that are highly sensitive to climate warming. The conclusions from our molecular and biochemical work on this project may impact the ways in which we manage coral disease. We have an ongoing dialog with several marine managers and conservation scientists who can use this information in developing management strategies. Our monitoring and experimental activities in Puerto Rico in the last year will be especially important in creating useful management approaches to address specific local considerations. The PIs, Post-docs and students associated with this project were actively involved in the International Coral Reef Symposium, held in Florida in 2008. Dr. Harvell was a plenary speaker. As a large, well-attended gathering of 4,000 coral scientists, this meeting provided opportunities to communicate our findings to a wide audience and to strengthen professional networks. These interactions have helped in the interpretation of our data, integration of our studies into larger global issues and in developing plans to expand our studies through collaborative efforts.

Publications

Mydlarz, L.D., Harvell, C.D., Holthouse, S., and Peters, E. 2008. Cellular responses in sea fan corals: Granular amoebocytes react to pathogen and climate stressors. PLoS One 3(3):e1811.
Rypien, K.L. 2008. African dust as an unlikely source of Aspergillus sydowii, the causative agent of sea fan disease. Marine Ecology Progress Series 367:125-131.
Rypien, K.L., Andras, J., and Harvell, C.D. 2008. Globally panmictic population structure in the opportunistic fungal pathogen Aspergillus sydowii. Molecular Ecology 17:4068-4078.
Couch, C., Mydlarz, L., Douglas, N.L., and Harvell, C.D. 2008. Variation in measures of immunocompetence of sea fan coral, Gorgonia ventalina, in the Florida Keys. Marine Biology 155(3):281-292.

Progress 10/01/06 to 09/30/07

Outputs
This last year focused on integrating our host immunity results and demographic studies into predictive modeling and into preparing manuscripts for publication. We have developed and implemented molecular methods, in vitro assays and histological techniques to test our primary hypothesis that some environmental facilitators compromise coral immunity. Our molecular studies have provided useful information about the mechanisms and dynamics of sea fan Aspergillosis. Our data suggest that Aspergillosis outbreaks are likely secondary infections in immune compromised individuals. Sea fans have also proved to be an unusually good study system to develop some of the first biochemical and histological assays for immune responses of corals and for delineating their timing and effectiveness. The tractability of the sea fan-Aspergillosis system allowed us to show experimentally that temperature stress increases some components of sea fan resistance and that increasing nutrient concentration can increase the rate of within-colony disease spread. In collaboration with researchers from the Australian Institute of Marine Sciences and the NOAA remote sensing project, we showed a link between temperature anomaly and disease outbreaks on the Great Barrier Reef and a critical dependency of large-scale disease outbreaks on coral density. Our systematic, long-term monitoring in the Caribbean also allowed us to examine the link between coral disease, community diversity, and population demographics. We have also processed the unique samples collected during the warm temperature anomaly of 2005 and have begun to assess how their immune responses differ from years of normal temperature range. In addition to the new publications indicated below, the results of this study have been disseminated through scientific meetings and workshops and through annual meetings of the PIs on this project.

Impacts
This project has significantly advanced our understanding of host and environmental factors that influence marine disease dynamics. These insights have resulted in two predictive models: An Integrated Projection Model (IPM) to examine population level impacts of disease, and a host-based model to examine the potential effects of environmental factors on coral immune success. Our molecular and Biochemical studies have given us better tools and techniques to examine coral disease that can be applied to this pathosystem, as well as expanded to other corals. Finally, we are aware that public education is now a critical component of scientific research in this country. Based on this project, we developed a Chemical Ecology and Antimicrobial Resistance module for the Ithaca Sciencenter program. This module (also used in Cornell's Freshman Explorations Program) consists of lectures on tropical invertebrate biology, disease ecology and natural products chemistry coupled with hands-on demonstrations of the antibacterial properties of coral and sponge extracts.

Publications

Baker, D. M., MacAvoy, S. E., and Kim, K. 2007. Environmental drivers of coral disease: The relationship between water quality, Delta15N, and Aspergillosis of Caribbean Sea Fan Corals. Marine Ecology Progress Series 343:123-130.
Bruno, J. F., Selig, E. R., Casey, K. S., Page, C., Willis, B., Harvell, C. D., Sweatman, H., and Melendy, A. M. 2007. Thermal stress and coral cover as drivers of disease outbreaks. Public Library of Science 5(6):1220-1227.
Douglas, N. L., Mullen, K., Talmage, S., and Harvell, C. D. 2007. Exploring the role of Chitinolytic Enzymes in the Sea Fan Coral Gorgonia ventalina. Marine Biology 150:1137-1144.
Harvell, C. D., Jordan-Dahlgren, E., Merkel, S., Rosenberg, E., Raymundo, L., Smith, G., Weil, E., and Willis, B. 2007. Coral disease, environmental drivers and the balance between coral and microbial associates. Oceanography 20:58-81.
Mydlarz, L. D. and Harvell, C. D. 2007. Peroxidase activity and inducibility in the sea fan coral exposed to a fungal pathogen. Comparative Biochemistry and Physiology, Part A. Molecular and Integrative Physiology 146:54-62.
Ward, J. R., Kim, K., and Harvell, C. D. 2007. Temperature affects coral disease resistance and pathogen growth. Marine Ecology Progress Series 329:115-121.
Mullen, K. M., Harvell, C. D., Alker, A. P., Dube, D., Jordan, E., Ward, J. R., and Petes, L. 2006. Host range and anti-fungal resistance to aspergillosis in three sea fan species in the Yucatan. Marine Biology 149:1355-1364.
Selig, E. R., Harvell, C. D., Bruno, J. F., Willis, B. L., Page, C. A., Sweatman, H., and Casey, K. 2006. Analyzing the relationship between ocean temperature anomalies and coral disease outbreaks at broad spatial scales. In: Phinney, J., Hoegh-Guldberg, O., Kleypas, J., Skirving, W., and Strong, A., editors. Corals and Climate Change: American Geophysical Union Press, pp. 111-128.

Progress 01/01/06 to 12/31/06

Outputs
Our molecular studies have demonstrated that the seafan-Aspergillus pathosystem can provide useful information about the mechanisms and impacts of introduction of terrestrial pathogens to marine environments and the resulting host-pathogen coevolution. Seafans have also proved to be an unusually good study system to develop some of the first biochemical and histological assays for immune responses of corals and for delineating their timing and effectiveness. One of the primary goals for this project was to test the hypothesis that warm temperature anomalies and other environmental factors can drive disease outbreaks. The tractability of the seafan-Aspergillus system allowed us to show experimentally that temperature stress increases some components of seafan resistance and that increasing nutrient concentration can increase the rate of within-colony disease spread. In collaboration with researchers from the Australian Institute of Marine Sciences and the NOAA remote sensing project, we showed a link between temperature anomaly and disease outbreaks on the Great Barrier Reef and a critical dependency of large-scale disease outbreaks on coral density. Our systematic, long-term monitoring in the Caribbean also allowed us to examine the link between coral disease, community diversity, and population demographics. We were also able to observe large increases in coral disease due to the largest temperature anomaly in 100 years during 2005.

Impacts
Coral reefs are currently being heavily impacted by bleaching and disease. The subsequent loss of coral cover has many negative consequences on the entire reef ecosystem. By studying the sea fan-fungus epizootic of Aspergillosis, we can elucidate some of the key mechanisms by which the disease spreads from organism to organism, as well as how the coral responds immunologically to infection. This project has significantly advanced our understanding of host and environmental factors that influence marine disease dynamics. These insights have resulted in two predictive models: An Integrated Projection Model (IPM) to examine population level impacts of disease, and a host-based model to examine the potential effects of environmental factors on coral immune success.

Publications

Ellner, S.P. and Rees, M. 2006. Integral projection models for species with complex demography. American Naturalist 167:410-428.
Garrison, V.H., Foreman, W.T., Genualdi, S., Griffin, D.W., Kellogg, C.A., Majewski, M.S., Mohammed, A., Ramsubhag, A., Shinn, E.A., Simonich, S.L. and Smith, G.W. 2006. Saharan dust-carrier of persistent pollutants, metals and microbes to the Caribbean. Revista de Biologia Tropical 54.
Gil-Aguedlo, D.L., Ali-Hassan, L., Kim, K. and Smith, G.W. 2006. Characterization of coral surface microbiota using metabolic profiling. Proceedings of the 10th International Coral Reef Symposium, pp. 146-152.
Gil-Aguedlo, D.L., Myers, C., Smith, G.W. and Kim, K. 2006. Changes in the microbial communities associated with Gorgonia ventalina during Aspergillosis infection. Diseases of Aquatic Organisms 69:89-94.
Mydlarz, L., Jones, L. and Harvell, C.D. 2006. Ecological immunity of invertebrates. Annual Review of Ecology, Evolution and Systematics 37:251-288.
Smith, G.W. and Weil, E. 2006. Diseases of coral reef organisms: Evolutionary aspects, current status and prognosis. Proceedings of the 10th International Coral Reef Symposium, pp. 132.
Ward, J.R. 2006. Ecology of marine diseases: Coral reef community diversity, host resistance, and climate change. Ph.D. Dissertation, Cornell University, 97 pp.
Ward, J.R., Rypien, K., Bruno, J., Harvell, C.D., Jordan, E., Mullen, K., Rodriguez-Martinez, R., Sanchez, J. and Smith, G. 2006. Coral diversity and disease in Mexico. Diseases of Aquatic Organisms 69:23-31.
Weil, E., Smith, G.W. and Gil-Agudelo, D. 2006. Status and progress in coral reef disease research. Diseases of Aquatic Organisms 69:1-7.

Progress 01/01/05 to 12/31/05

Outputs
This year saw a large focus on developing immunological assays to test our primary hypothesis that some environmental facilitators compromise coral immunity. In 2004/2005 we developed assays for peroxidase, chitinase, prophenyloxidase and melanization to study the cellular responses of Gorgonia ventalina to infection by the fungal pathogen Aspergillus sydowii. We found that experimentally infected G. ventalina show an induction of peroxidase activity and a large increase in aggregation of amoebocytes (wandering cytotoxic cells) after an 8 day incubation with live fungus. By contrast, we detected relatively high constitutive levels of exochitinase activity in these tissues that dropped significantly upon exposure to the fungus, but also upon injury, agitation or manipulation. A concurrent burst of exochitinase in the surrounding water suggests a role for chitinases in defense against opportunistic infection by chitinaceous pathogens during stress and injury. We also had the opportunity to test directly the hypothesis that coral disease outbreaks are driven by warm temperature anomalies.

Impacts
Coral reefs are currently being heavily affected by bleaching and disease. The subsequent loss of coral cover has many negative consequences on the entire reef ecosystem. By studying the sea fan-fungus epizootic of Aspergillosis, we can elucidate some of the key mechanisms by which the disease spreads from organism to organism as well as how the coral responds immunologically to infection. This work has widespread effects to further our awareness and knowledge of marine diseases and contribute to our understanding of coral physiology.

Publications

Alker, A., Kim, K., Dube, D., and Harvell, C.D. 2004. Localized induction of a generalized response against multiple biotic agents in Caribbean sea fans. Coral Reefs 23:397-405.

Progress 01/01/04 to 12/31/04

Outputs
We have been investigating the biochemical defenses of Gorgonia ventalina to infection by Aspergillus syndowii both in field-collected samples and in isolated cell culture experiments. We are analyzing general stress responses, such as release of oxygen radicals and upregulation of peroxidase enzymes as well as fungal specific chitinolytic enzymes. With assays for these enzymatic responses established, we are testing conditions that may facilitate fungal infection or that may encourage coral chemical defenses, such as temperature, tissue damage, and exposure to antagonist corals. In order to better understand the significance of these enzymatic responses in defense against the fungus, we have developed a high-throughput, small volume anti-fungal assay to test our cell culture and whole coral isolates. We have been investigating the Origins of Aspergillus sydowii in Caribbean reef communities. We have optimized DNA extraction methods and microsatallite loci primers for Aspergillus sydowii in order to extract and analyze DNA from the large number of diseased sea fan samples collected in summer 2003 and 2004. We also have six primers developed for Gorgonia ventalina polymorphic microsatellite loci that will allow us to investigate Genetic diversity and population structure. We are now using these loci to begin genotyping over two thousand sampled individuals collected from 17 sites in Florida, Mexico, Belize and the Bahamas. These markers will be used to map the spatial population structure of G. ventalina and will ultimately allow inferences to be drawn about dispersal, age class mortality, and other phenomena that affect demographics such as disease. We have continued to add to our long-term data set on sea fan aspergillosis prevalence (percent infected) and severity, and continue to catalog gorgonian species richness and diversity in reef communities of the Florida Keys. The results of these surveys will allow us to determine if the trend of a declining epizootic is still present. We started mathematical modeling efforts using a 5-year demographic set developed during the previous granting interval and nitrate-temperature mesocosm experiments and we are well underway in our collaboration with Antje Baeumner to develop a field-based biosensor.

Impacts
Coral reefs are currently being heavily affected by bleaching and disease. The subsequent loss of coral cover has many negative consequences on the entire reef ecosystem. By studying the sea fan-fungus epizootic of Aspergillosis, we can elucidate some of the key mechanisms by which the disease spreads from organism to organism as well as how the coral responds immunologically to infection. This work has widespread effects to further our awareness and knowledge of marine diseases and contribute to our understanding of coral physiology.

Publications

Kim, K. and Harvell, C.D. 2004. The rise and fall of a 6-year coral-fungus epizootic. American Naturalist 164:S52-S63).

Progress 01/01/03 to 12/31/03

Outputs
We completed work on the old NSF, and published 2 papers on sea fan responses to fungal disease (Petes et al 2003, Bruno et al 2003). Work is underway on the new NSF, developing assays for chitinase and prophenyloxidase, as measures of anti-fungal resistance. We also started the modelling effort using a 5-year demographic set developed during the previous granting interval. One successful study supports our hypothesis that nitrate will accelerate the progress of Aspergillus infections (Bruno et al., 2003), and the nitrate-temperature mesocosm experiments will be started in March. We are well underway in our collaboration with Antje Baeumner to develop a field-based biosensor.

Impacts
Our project on the coral-Aspergillus study system is having a large impact. In addition to several invitations to speak in symposia at National Meetings, I presented our work to Environmental Defense in a special focus series on Coral Reef Conservation. The World Bank has asked me to chair a worldwide program on Coral Disease. I also co-chaired (with Rita Colwell, director of NSF) a briefing for congressional staffers on the Oceans and Disease. I organized a symposium session on Diseases in Nature at the Evolution meetings as the Vice-President of the Society of American Naturalists.

Publications

Bruno, J. F., Petes, L. E., Harvell, C. D., and Hettinger, A. 2003. Nutrient Enrichment Can Increase the Severity of Coral Diseases. Ecology Letters 6(12):1056-1061.
McCallum, H., Harvell, D., and Dobson, A. 2003. Rates of Spread of Marine Pathogens. Ecology Letters 6(12):1062-1067.
Petes, L. E., Harvell, C. D., Peters, E. C., Webb, M. A. H., and Mullen, K. M. 2003. Pathogens Compromise Reproduction and Induce Melanization in Caribbean Sea Fans. Marine Ecology Progress Series 264:167-171.

Progress 01/01/02 to 12/31/02

Outputs
We have completed all field work on our NSF grant and are continuing with final lab work and papers. We have made progress in studying coral resistance to fungal disease, and detected inducible anti-fungal chemistry, pinpointed melanin deposits adjacent to disease infestations, and developed methods to quantify chitinase production. This year we finished a project as part of an undergraduate honors thesis, showing that the pathogen suppresses reproduction in its coral host.

Impacts
Our project on the coral-Aspergillus study system is having a large impact. In addition to several invitations to speak in symposia at National Meetings, I have been asked to present our work to Environmental Defense and the World Bank has asked me to chair a worldwide program on Coral Disease. I have given over 25 press interviews this year on various aspects of our research.

Publications

Dube, D., A. P. Alker, K. Kim, and C. D. Harvell. 2002. Size structure and geographic variation in chemical resistance of sea fan corals (Gorgonia ventalina) against a fungal pathogen. Marine Ecology Progress Series 231: 139-150.
Harvell, C. D., C. Mitchell, J. Ward, S. Altizer, A. Dobson, and M. Samuel. 2002. Climate warming and disease risks for terrestrial and marine biota. Science 296:2158-2162.
Jolles, A., P. Sullivan, A. P. Alker, and C. D. Harvell. 2002. Disease transmission of aspergillosis in sea fans: Inferring process from spatial pattern. Ecology 83:2373-2378.
Kim, K., A. Dobson, F. M. D. Gulland, and C. D. Harvell. 2002. Disease and the conservation of marine diversity. In Conservation of Marine Ecosystems. E. Norse and L. Crowder, eds. Island Press.

Progress 01/01/01 to 12/31/01

Outputs
We have completed most of the proposed work on our NSF grant and are working on analyzing samples and data to write up publications. This year we analyzed (in collaboration with S. Ellner) the monitoring data from the Florida Keys and were able to detect a significant correlation of disease impact with water quality (NOX and Chlor a). Although often discussed, very few studies have good significant data on the role of water quality, so we feel this is an important advance. We have made significant advances in studying coral resistance and discovering the role of melanin, chitinase, and anti-fungal activity against aspergillus. Finally, we found that Aspergillus infects a wider host range of gorgonian corals, and is not a specialist on seafans.

Impacts
Our study of the seafan-Aspergillus system is having a significant impact. Our study is showing the large impacts caused by disease in tropical marine oceans and also we are developing innovative experimental methods for studying disease. One measure of the impact of our work is regular invitations to participate in National and International Symposia and involvement in NCEAS working groups on Conservation and Disease.

Publications

Harvell, C. D., Kim, K., Quirolo, C., Weir, J., and Smith, G. W. 2001. Coral bleaching and disease: Contributors to 1998 mass mortality in Briareum asbestinum (Octocorallia, Gorgonacea). Hydrobiologia 460:97-104.

Progress 01/01/00 to 12/31/00

Outputs
In the second year of our NSF project we completed inoculation experiments on clone-specific anti-fungal resistance and inducible resistance in both the laboratory and field. Data analysis and preparation of a publication are underway. We also completed spatial analysis of diseased seafans and a paper is ready for submission (Jolles et al., in prep). We have documented unusually large impacts of aspergillosis on field populations of seafans and completed one book chapter (Kim and Harvell, in press) and had one paper reviewed in Science (declined). We published results of temperature effects on the pathogen (Alker et al., in press) and worked out protocols for testing temperature effects on the complete pathosystem (host and pathogen). We detected unusual impacts of a disease on a related coral, Briareum asbetinum during the 1998 EL Nino (Harvell et al., in press).

Impacts
Our study of the seafan-Aspergillosis is having a significant impact, as measured by my invitations to talk about the work at Ocean Science Day 2000 (a congressional information session on health of the oceans). Our study is helping to show the large impacts caused by disease in the ocean and some experimental approaches to studying disease in natural populations. I also receive regular invitations to speak and organize in symposia at national meetings, such as Ecological Society of America (for summer 2001).

Publications

Kim, K., Harvell, C. D., Smith, G., Merkel, S., and Kim, P. D. 2000. Role of secondary chemistry in fungal disease resistance of sea fans (Gorgonia spp) Marine Biology 136:259-267.
Kim, K., Kim, P. D., and Harvell, C. D. 2000. Antifungal properties of gorgonian corals. Marine Biology 137:393-401.

Progress 01/01/99 to 12/31/99

Outputs
This year we completed set-up of the monitoring program in the Florida Keys. We successfully developed protocols for inoculating colonies in the laboratory and the field and initiated studies of variation in resistance among clones of seafans. The work to elucidate chemicals underlying anti-fungal activity continues.

Impacts
(N/A)

Publications

Harvell, C. D., K. Kim, J. M. Burkholder, R. R. Colwell, P. R. Epstein, D. J. Grime, E. E. hofman, E. K. Lipp, A. D. M. E. Osterhaus, R. M. Overstreet, J. W. Porter, G. Smith, G. R. Vasta. 1999. Emerging marine diseases - climate links and anthropogenic factors. Science 285:1505-1510.