Distribution, host range and large-scale spatial variability in black band disease prevalence on the Great Barrier Reef, Australia

Abstract

The prevalence and host range of black band disease (BBD) was determined from surveys of 19 reefs within the Great Barrier Reef Marine Park, Australia. Prevalence of BBD was compared among reefs distributed across large-scale cross-shelf and long-shelf gradients of terrestrial or anthropogenic influence. We found that BBD was widespread throughout the Great Barrier Reef (GBR) and was present on 73.7% of the 19 reefs surveyed in 3 latitudinal sectors and 3 cross-shelf positions in the summer of 2004. Although BBD occurred on all mid-shelf reefs and all but one outershelf reefs, overall prevalence was low, infecting on average 0.09% of sessile cnidarians and 0.1% of scleractinian corals surveyed. BBD affected ~7% of scleractinian taxa (25 of approximately 350 GBR hard coral species) and 1 soft coral family, although most cases of BBD were recorded on branching Acropora species. Prevalence of BBD did not correlate with distance from terrestrial influences, being highest on mid-shelf reefs and lowest on inshore reefs (absent from 66%, n = 6, of these reefs). BBD prevalence was consistently higher in all shelf positions in the northern (Cooktown/Lizard Island) sector, which is adjacent to relatively pristine catchments compared to the central (Townsville) sector, which is adjacent to a more developed catchment. BBD cases were clustered within reefs and transects, which was consistent with local dispersal of pathogens via currents, although the spread of BBD was not dependent on the density or cover of any of the coral taxa examined. In combination, these results suggest that BBD is part of the natural ecology of coral assemblages of the GBR, and its prevalence is relatively unaffected by terrestrial influences on the scales characteristic of cross-shelf gradients.KEY WORDS: Black band disease · BBD · Coral disease · Great Barrier Reef · GBR · Cyanobacteria · Skeletal eroding band · SEB · BleachingResale or republication not permitted without written consent of the publisher

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

“…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. Alternate hypotheses, including vector-borne transmission from non-coral reservoirs or between diseased and healthy corals have also been suggested (Aeby and Santavy, 2006;Casey et al, 2014).…”

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

“…Light intensity is also an important seasonal variable that may contribute to seasonal patterns in the dynamics of BBD. Evidence that water depth and turbidity are negatively correlated with disease abundance (Kuta & Richardson 2002;Page & Willis 2006) also suggests that the availability of light may govern occurrence of the disease. High light has been demonstrated to elicit an immediate behavioural response in the microbial community, causing upward migration of Beggiatoa spp.…”

“…Progression rates of up to 2 cm d K1 have been recorded on Caribbean corals , leading to death of entire coral colonies. BBD has been reported from reefs throughout the Caribbean, Red Sea and Indo-Pacific (reviewed in Sutherland et al 2004), affecting at least 42 Caribbean and 57 Indo-Pacific coral species (Sutherland et al 2004;Kaczmarsky 2006;Page & Willis 2006). In the Caribbean, while BBD prevalence (proportion of infected colonies in a population) is typically lower than 5 per cent, an exceptional event (50% prevalence) was reported for Montastrea annularis in the Florida Keys in 1993, and BBD has been a major contributor to the declines in coral cover in Caribbean populations (reviewed in Green & Bruckner 2000).…”

“…Given that no BBD had been observed in field studies over the past 15 years at this site (B. L. Willis 2006, personal observation) or on adjacent reefs surrounding nearby islands in the Palm Island group in a recent survey (Page & Willis 2006), the sudden increase in BBD cases can be considered an epizootic (sensu Stedman 2000). Since first detecting BBD, this site has been systematically monitored for 2.7 years to document the dynamics of BBD in a Montipora assemblage.…”

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

“…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).…”