Distribution and Disease Prevalence of Coral Associated Bacteria at Some Impacted Red Sea Reefs

Al Hammady Mam,Mohamed Mh

doi:10.4172/2332-2543.1000158

Abstract

Prevalence and distribution of coral disease were surveyed in three impacted sites at Red Sea coast. Prevalence were significant difference between studied reefs (ANOVA; F = 10.777, p < 0.0001). Sites closed to oil pollution (sites 1 and 2) displayed much higher levels of disease prevalence (25.3% ± 8.3 2 and 18.5% ± 3.1, respectively), than site 3 that close to landfilling (12.9% ± 2.1). Totally, 99coral braches, representing 20 species affected by at least 12 diseases. However, site 3 is characterized by the highest diversity (Simpson’s Index = 0.081) and highest percentage cover of life coral (35.2% ± 11.4) showed the lowest coral diseases number (3). In opposite, 10 coral diseases were recorded at site 1, and 8 coral diseases at site 2. While, the coral disease atramentous necrosis attained the highest prevalence percentage at sites 1 and 2 (3.2% and 4.5%, respectively), did not recorded at site 3. Sediment damage disease recorded the highest prevalence percentage at site 3 (5.1%), but did not record at sites 1 and 2. Diseases having lowest percentage cover were white band disease (sites 1 and 2) and white tips disease. The most commonly distributed disease (atramentous necrosis) infected five corals in site 1 and six corals in site 2. The least commonly distributed disease (white tips) infected only two corals (Acropora humilis and Acropora formosa) at site 3. The genus Porites at sites was particularly vulnerable to all diseases. However, Galaxea fasicularis at site 3 recorded the highest percent cover of sediment damage disease. Coral disease atramentous necrosis is always associated with Vermetidae predation and Tridacna boring. While, Drupels predation is associated with skeletal eroding band. Aggressive filamentous algal overgrowth is associated with sediment damage disease at site 3. The pathogenic bacterium isolated from the diseased Stylophora pistillata, Porites sp., and Acropora sp., referred to as Vibrio fischeri.

Highlights

IntroductionAn important factor contributing to coral decline is the widespread infectious diseases, especially coral reef of the Red Sea [1,2]
We are witnessing on of coral reef decline
Our surveys have provided baseline information on the prevalence of coral disease affecting reefs in the Red Sea, a country within the global center of coral reef biodiversity. As it is obvious from the present study, diseases prevalence were significant differences between reefs, of which reefs closed to oil pollution displayed much higher levels of disease prevalence, % cover of diseases and % cover of dead corals, than reef close to landfilling

Summary

Introduction

An important factor contributing to coral decline is the widespread infectious diseases, especially coral reef of the Red Sea [1,2]. Coral disease is an abnormal condition of an organism that causes organism disfunctions, associated with strange symptoms and signs ICRI / UNEPWCMC, 2010. Disease causation may be result from pathogens, environmental stressors, or a combination of biotic and abiotic factors [3]. Biotic diseases are caused by pathogenic microorganisms such as viruses, bacteria, fungi, and protists and are often species-specific [4,5] and infectious [6]. Abiotic diseases result from natural and anthropogenic stressors associated with exposure to pollutants [1,7]. Other studies suggested a link between snail predators and disease spread such as outbreak of ‘white syndrome’ in Red Sea acroporid corals correlated with an outbreak in the coral livorous snail Drupellacornus [10]. Exposure to Hermodice carunculata (polychaete) infected with the bleaching pathogen Vibrio shiloi has been shown to induce bleaching in the Mediterranean coral Oculina patagonicain laboratory aquaria [11]

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