Natural Disease Resistance in Threatened Staghorn Corals

Abstract

Disease epidemics have caused extensive damage to tropical coral reefs and to the reef-building corals themselves, yet nothing is known about the abilities of the coral host to resist disease infection. Understanding the potential for natural disease resistance in corals is critically important, especially in the Caribbean where the two ecologically dominant shallow-water corals, Acropora cervicornis and A. palmata, have suffered an unprecedented mass die-off due to White Band Disease (WBD), and are now listed as threatened under the US Threatened Species Act and as critically endangered under the IUCN Red List criteria. Here we examine the potential for natural resistance to WBD in the staghorn coral Acropora cervicornis by combining microsatellite genotype information with in situ transmission assays and field monitoring of WBD on tagged genotypes. We show that six percent of staghorn coral genotypes (3 out of 49) are resistant to WBD. This natural resistance to WBD in staghorn corals represents the first evidence of host disease resistance in scleractinian corals and demonstrates that staghorn corals have an innate ability to resist WBD infection. These resistant staghorn coral genotypes may explain why pockets of Acropora have been able to survive the WBD epidemic. Understanding disease resistance in these corals may be the critical link to restoring populations of these once dominant corals throughout their range.

Temporal changes in benthic assemblages on Florida Keys reefs 11 years after the 1997/1998 El Niño

“…Extant stands of these corals in the Florida Keys are now estimated to be <1% of their original size as a result of disease, hurricanes and thermal stress (Dustan & Halas 1987, Porter & Meier 1992, Precht & Miller 2006). The few remaining stands of A. palmata have continued to decline (Porter et al 2012, Williams & Miller 2012, and Allee effects now pose significant barriers to recovery of the small, remnant population in the Florida Keys (Vollmer & Kline 2008, Williams et al 2008, Porter et al 2012. Irrespective of acroporids, total stony coral cover continued to decline on shallow forereefs between 1999 and 2009 (Table 1).…”

No two reefs are created equal: fine-scale population structure in the threatened coral species Acropora palmata and A. cervicornis

“…When genetic methods are coupled with ecological and oceanographic studies (Baums et al 2006a, Galindo et al 2006, Hellberg 2007, Grober-Dunsmore et al 2007, Zubillaga et al 2008), a more comprehensive management plan can be implemented. Management decisions can be further fine-tuned by the inclusion of genetic information in restoration projects (Baums 2008, Shearer et al 2009) and by the identification of disease-resistant genotypes (Vollmer & Kline 2008). …”

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

“…Some evidence suggest corals have an innate ability to resist disease via their genetic makeup (Vollmer and Kline, 2008), while other corals that are predisposed to disease may be affected when energy resources are depleted and host defenses are compromised. Physical damage to corals may result in physiological changes that promote pathogenic infestation.…”