title: Shifting white pox aetiologies affecting Acropora palmata in the Florida Keys, 1994-2014.
abstract: We propose 'the moving target hypothesis' to describe the aetiology of a contemporary coral disease that differs from that of its historical disease state. Hitting the target with coral disease aetiology is a complex pursuit that requires understanding of host and environment, and may lack a single pathogen solution. White pox disease (WPX) affects the Caribbean coral Acropora palmata. Acroporid serratiosis is a form of WPX for which the bacterial pathogen (Serratia marcescens) has been established. We used long-term (1994-2014) photographic monitoring to evaluate historical and contemporary epizootiology and aetiology of WPX affecting A. palmata at eight reefs in the Florida Keys. Ranges of WPX prevalence over time (0-71.4%) were comparable for the duration of the 20-year study. Whole colony mortality and disease severity were high in historical (1994-2004), and low in contemporary (2008-2014), outbreaks of WPX. Acroporid serratiosis was diagnosed for some historical (1999, 2003) and contemporary (2012, 2013) outbreaks, but this form of WPX was not confirmed for all WPX cases. Our results serve as a context for considering aetiology as a moving target for WPX and other coral diseases for which pathogens are established and/or candidate pathogens are identified. Coral aetiology investigations completed to date suggest that changes in pathogen, host and/or environment alter the disease state and complicate diagnosis.
authors.affiliation: Department of Biology, Rollins College, Winter Park, FL 32789, USA kpsutherland@rollins.edu.
authors.forename: Kathryn P
authors.identifier: http://orcid.org/0000-0002-8192-1500
authors.initials: KP
authors.lastname: Sutherland
authors.affiliation: Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Brett
authors.initials: B
authors.lastname: Berry
authors.affiliation: Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Park
authors.affiliation: Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Dustin W
authors.initials: DW
authors.lastname: Kemp
authors.affiliation: Odum School of Ecology, University of Georgia, Athens, GA 30602, USA Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA.
authors.forename: Keri M
authors.initials: KM
authors.lastname: Kemp
authors.affiliation: Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA.
authors.forename: Erin K
authors.initials: EK
authors.lastname: Lipp
authors.affiliation: Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
authors.forename: James W
authors.initials: JW
authors.lastname: Porter
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000382:microbiology*; D057894:Coral Reefs; D005431:Florida; D054884:Host-Pathogen Interactions; D012706:Serratia marcescens / Q000502:physiology*; D013997:Time Factors
keywords: Acropora palmata; acroporid serratiosis; coral disease; white pox