Sea fan Fungal Disease

[Drew Harvell]

Dear Colleagues:

>We have been working on the sea fan epizootic in the Florida Keys,
>Bahamas and Yucatan, MX for three years now. The disease is caused by
>the fungus Aspergillus sydowii (at least in the Caribbean) which is
>thought to be terrestrial. Although our analysis is ongoing,  in the
>Florida Keys we have
>detected correlation between various water quality parameters and disease
>severity at some sites and times.  Our monitoring program, supported by
>NSF and NOAA/NURC now encompasses nine sites spanning the Keys and
>consists of 3 transects per site; we are hoping to increase coverage among
>sites.  For each fan on the transect we
>record its size, disease state and estimate the severity of disease
>-- this protocol is giving us good epidemiologically structured
>monitoring data. To confirm the causative agent as A. sydowii, the
>infected area has to be plated out to isolate the putative pathogen,
>and then identified using sequence data. We have been able to carry
>out subsequent inoculation experiments to show that the isolated
>fungus is indeed the pathogen (i.e., fulfilled Koch's Postulates).
>Information about the epizootic and recent papers we have published
>are provided on our websites:
>
>http://www.es.cornell.edu/harvell/harvell.html
>http://www.people.cornell.edu/pages/kk60/
>
We will be working later this week in the FLorida Keys,  and will check the
sites mentioned by Billy Causey and Ken Nedimeyer and appreciate the
information.  We will be housed at the NOAA-NURC/UNCW base in Key Largo.
Please contact us by email if you have questions or notice new episodes of
seafan mortality.  New episodes can be identified as recently killed coral
coenenchyme, exposing the gorgonin axis and before fouling algae can
colonize.  Below we have listed some references we hope will be useful
about this and  previous seafan epizootics.

Sincerely,  Drew Harvell (CDH5 at Cornell.edu) and Kiho Kim (KK60 at Cornell.edu)
>
>
>Garzón-Ferreira, J. & Zea, S. A mass mortality of Gorgonia ventalina
>(Cnidaria: Gorgonidae) in the Santa Marta area, Caribbean coast of
>Colombia. Bull Mar Sci 50, 522-526 (1992).
>
>Geiser, D., Taylor, J., Ritchie, K. & Smith, G. Cause of sea fan
>death in the West Indies. Nature 394, 137-138 (1998).
>
>Harvell, C., et al. Emerging marine diseases-climate links and
>anthropogenic factors. Science 285, 1505-1510 (1999).
>
>Kim, K., Harvell, C., Kim, P., Smith, G. & Merkel, S. Role of
>secondary chemistry in fungal disease resistance of sea fans
>(Gorgonia spp.). Mar Biol 136, 259-267 (2000).
>
>Nagelkerken, I., et al. Widespread disease in Caribbean sea fans: I.
>Spreading and general characteristics. International Coral Reef Symp
>1, 679-682 (1996).
>
>Nagelkerken, I., et al. Widespread disease in Caribbean sea fans: II.
>Patterns of infection and tissue loss. Mar Ecol Prog Ser 160, 255-263
>(1997).
>
>Slattery, M. Fungal pathogenesis of the sea fan Gorgonia ventalina:
>direct and indirect consequences. Chemoecology 9, 97-104 (1999).
>
>Smith, G., Ives, L., Nagelkerken, I. & Ritchie, K. Caribbean sea-fan
>mortalities. Nature 383, 487 (1996).
>
>Guzmán, H. & Cortéz, J. Mortand de Gorgonia flabellum Linnaeus
>(Octocorallia: Gorgoniidae) en la Costa Cribe de Costa Rica. Rev Biol
>Trop 32, 305-308 (1984).


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Drew Harvell
Professor
Department of Ecology and Evolutionary Biology
Cornell University
Ithaca, NY 14853

VOICE:  607-254-4274   FAX: 607-255-8088  email:cdh5 at cornell.edu
http://www.es.cornell.edu/harvell/harvell.html

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