Dynamics of seasonal outbreaks of black band disease in an assemblage of Montipora species at Pelorus Island (Great Barrier Reef, Australia)

Abstract

Recurring summer outbreaks of black band disease (BBD) on an inshore reef in the central Great Barrier Reef (GBR) constitute the first recorded BBD epizootic in the region. In a 2.7 year study of 485 colonies of Montipora species, BBD affected up to 10 per cent of colonies in the assemblage. Mean maximum abundance of BBD reached 16G6 colonies per 100 m 2 (nZ3 quadrats, each 100 m 2 ) in summer, and decreased to 0-1 colony per 100 m 2 in winter. On average, BBD lesions caused 40 per cent tissue loss and 5 per cent of infections led to whole colony mortality. BBD reappearance on previously infected colonies and continuous tissue loss after the BBD signs had disappeared suggest that the disease impacts are of longer duration than indicated by the presence of characteristic signs. Rates of new infections and linear progression of lesions were both positively correlated with seasonal fluctuations in sea water temperatures and light, suggesting that seasonal increases in these environmental parameters promote virulence of the disease. Overall, the impacts of BBD are greater than previously reported on the GBR and likely to escalate with ocean warming.

Microbiome shifts and the inhibition of quorum sensing by Black Band Disease cyanobacteria

“…Individual coral colonies in which BBD has halted are 3.5 times more likely to develop signs of the disease in subsequent years (Sato et al, 2009). Analyses of the within-ecosystem, spatiotemporal patterns of the appearance of BBD point to various models, including transmission by water currents, stochastic appearance of lesions and direct colonyto-colony transmission (Bruckner et al, 1997;Sato et al, 2009;Zvuloni et al, 2009). These observations also do not rule out a hypothesis that the spatiotemporal distribution of BBD cases on the reef correlates with water quality parameters (Page and Willis, 2006), which may serve as environmental triggers for community shifts mediated by BBD members.…”

“…It spikes in warmer, sunnier months, and once a BBD outbreak takes place within a given ecosystem, it tends to reoccur each year (Zvuloni et al, 2009;Sato et al, 2009;Kuehl et al, 2011;Muller and van Woesik, 2011;Sato et al, 2011). Individual coral colonies in which BBD has halted are 3.5 times more likely to develop signs of the disease in subsequent years (Sato et al, 2009).…”

“…It spikes in warmer, sunnier months, and once a BBD outbreak takes place within a given ecosystem, it tends to reoccur each year (Zvuloni et al, 2009;Sato et al, 2009;Kuehl et al, 2011;Muller and van Woesik, 2011;Sato et al, 2011). Individual coral colonies in which BBD has halted are 3.5 times more likely to develop signs of the disease in subsequent years (Sato et al, 2009). Analyses of the within-ecosystem, spatiotemporal patterns of the appearance of BBD point to various models, including transmission by water currents, stochastic appearance of lesions and direct colonyto-colony transmission (Bruckner et al, 1997;Sato et al, 2009;Zvuloni et al, 2009).…”

Successional changes in bacterial communities during the development of black band disease on the reef coral, Montipora hispida

“…Currently, however, little is known regarding how bacterial pathogens form the black band on host corals or how changes in microbial communities lead to onset of the disease. Given the potential for BBD to cause substantial tissue loss in coral populations (reviewed in Green and Bruckner, 2000;Sato et al, 2009) and the likelihood that effects of the disease will be exacerbated as seawater temperatures warm with predicted climate change Kuta and Richardson, 2002;Borger and Steiner, 2005;Voss and Richardson, 2006;Rodriguez and Croquer, 2008;Sato et al, 2009), there is need for greater understanding of early stages in the onset of the disease if BBD is to be managed effectively.…”

“…Black band disease (BBD), which manifests as a darkly pigmented microbial mat that migrates across live coral colonies causing necrosis of coral tissues (reviewed in Richardson, 2004), is a major contributor to ongoing loss of reef building corals worldwide, particularly in the Caribbean Goreau et al, 1998;Green and Bruckner, 2000;Sutherland et al, 2004;Kaczmarsky, 2006;Page and Willis, 2006;Sato et al, 2009). BBD has been termed a poly-microbial disease because a primary causative agent(s) has not been identified and a tightly organized, complex microbial consortium appears to act in concert to cause coral tissue necrosis (Richardson et al, 1997Richardson, 2004).…”