Disease incidence is related to bleaching extent in reef‐building corals

Abstract

Recent outbreaks of coral bleaching and disease have contributed to substantial declines in the abundance of reef-building coral. Significant attention has been paid to both phenomena in order to determine their effect on reef trajectories. Although each is positively correlated with high temperatures, few studies have explored the potential links between bleaching and disease. A longitudinal study of corals in the Florida Keys was therefore conducted during the 2005 Caribbean bleaching event to quantify bleaching extent and disease incidence in corals, and to determine whether they were related or if they acted as discrete phenomena. These data indicated that overall, a positive correlation exists between bleaching extent and disease incidence. However, the specific interactions between these two phenomena varied among disease bleaching combinations. Montastraea faveolata colonies with greater bleaching intensities later developed white plague (WP) infections. Meanwhile, Siderastrea siderea colonies with dark spot disease (DS) bleached more extensively than apparently healthy colonies. Finally, bleaching and black band disease (BB) co-occurred on Colpophyllia natans throughout the bleaching event. WP, BB, and bleaching are each independently capable of changing the structure of coral populations through loss of living tissue, and DS is an important indicator of reef health. Understanding the dynamics of how these mortality sources interact is critical to understanding mortality patterns and predicting how reef communities will respond to future events.

Spatial and temporal patterns of scleractinian coral, soft coral, and zoanthid disease on a remote, near-pristine coral reef (Palmyra Atoll, central Pacific)

“…Environmental stress impairs coral host immunity and promotes pathogen virulence (Fitt et al 2001, Blanford et al 2003, Lafferty & Holt 2003, Ward et al 2007). As such, disease prevalence (predominantly tissue loss diseases) often increases during or proceeding coral bleaching events when temperatures are high and the coral hosts are compromised (Jones et al 2004b, Miller et al 2006, Whelan et al 2007, Brandt & McManus 2009, Bruckner & Hill 2009, Cróquer & Weil 2009). At Palmyra, overall disease prevalence within our permanent transects was higher in 2009 than 2008 (by 0.14%).…”

Coral transcriptome and bacterial community profiles reveal distinct Yellow Band Disease states inOrbicella faveolata

“…Since the mid-1970s (Dustan, 1977) coral disease events have become pervasive throughout the world's oceans (Sutherland et al, 2004;Weil et al, 2006;Bourne et al, 2009). Anthropogenic pressures such as increasing sea surface temperatures, coastal development, depletion of fisheries and high-nutrient effluents, impact coral health and exacerbate disease outbreaks (Bruno et al, 2003;Cervino et al, 2004;Bruno et al, 2007;Brandt and McManus, 2009). Metagenomic approaches have revealed higher numbers of potentially pathogenic bacteria along gradients of anthropogenic activity .…”

Disease Prevalence and Snail Predation Associated with Swell-Generated Damage on the Threatened Coral, Acropora palmata (Lamarck)

“…In fact, this study supported others where disease manifested on corals affected by physical damage (Bak and Criens, 1981;Knowlton et al, 1981;Williams et al, 2008), but it was deferred until periods of higher sea water temperatures (when lesions caused by the swells had healed) suggesting that the autogenous physiological state of the colony plays an important role in disease initiation. This hypothesis is supported in studies where coral bleaching, a sign of physiological stress to the coral, was positively correlated with elevated levels of disease on Caribbean reefs, sometimes several months after bleaching (Muller et al, 2008;Brandt and McManus, 2009;Cróquer and Weil, 2009;Miller et al, 2009;Rogers and Muller, 2012). In addition to physical damage, the March swells may have increased nutrients via water mixing and/or mobilization of sediments, both of which are also associated with major storms.…”