1.Prevalence of coral diseases in the coastal waters of Kota Kinabalu: The potential of microbial and environmental agents
Aslam Nor' ; ashikin Zuhairi ; Fikri Akmal Khodzori ; Siti Nur Hazwani Oslan ; Nurzafirah Mazlan ; Hariz Khairul Hisham ; Kiu Yee Tong ; Abdul Muhaimin Zepri
Malaysian Journal of Microbiology 2023;19(no.6):735-751
Aims:
The Indo-Pacific coral populations are under increasing threats from bleaching events and coral disease
outbreaks. However, there is a significant gap in data and research on coral diseases in Malaysian waters. This study aimed to assess the prevalence of coral diseases and signs of compromised health at 27 reef sites in the coastal waters of Kota Kinabalu, Sabah.
Methodology and results:
We conducted coral surveys using the Coral Video Transect (CVT) method and measured
the prevalence using Coral Point Count with Excel Extension (CPCe) software. Our findings indicated that the majority of reefs appeared healthy (82.9% ± 1.8), while a smaller percentage displayed signs of disease (5.0% ± 0.6) or compromised health (12.1% ± 1.5). Reef sites exposed to higher levels of human activities exhibited a greater prevalence of coral diseases (e.g. yellow band disease, ulcerative white spots and skeletal eroding band) and signs of compromised health (e.g. sediment necrosis, skeletal damage and algal overgrowth). A total of 51 scleractinian hard coral genera were affected, with Porites and Acropora being the most predominantly affected by sediment necrosis and skeletal damage, respectively. A review of molecular approaches identified various coral pathogens, including Vibrio spp., which could potentially contribute to the occurrence of coral disease.
Conclusion, significance and impact of study
Unsustainable coastal development with unregulated human activities can exacerbate the severity of coral diseases and signs of compromised health. Therefor
2.Pathogenic Vibrio spp. identified for white syndrome coral disease in Tioman Island Marine Park, Malaysia
Fikri Akmal Khodzori ; Shahbudin Saad ; Nur Nazifah Mansor ; Nur Amalin Nadia Mat Nasir ; Nik Nadiah Nik Abdul Khalid ; Fikri Zhafran Rawi
Malaysian Journal of Microbiology 2021;17(1):69-79
Aims:
Coral diseases have emerged over the last several decades, causing a loss of live coral cover in the Caribbean
and Indo-Pacific reefs. Hence, microbiological and disease cultural techniques are commonly used to investigate their
causative microbial agents. This is the first study to identify the potential of pathogenic Vibrio spp. isolated from
apparently white syndrome (WS) coral disease in Tioman Island Marine Park using biochemical and molecular
techniques.
Methodology and results:
The Vibrio colonies were isolated from 108 samples of WS infected corals (Acropora
cytherea and Montipora aequituberculata) including seawater, sediment and algae found adjacent to infected coral
colonies. A total of one hundred representative Vibrio isolates were characterized and most of them (n=50) were
identified as V. vulnificus, V. alginolyticus and Photobacterium damselae following biochemical analysis. The molecular
analysis revealed six Vibrio spp. (V. coralliilyticus, V. hepatarius, V. brasiliensis, V. tubiashi, V. campbellii, V.
ishigakensis) and one Photobacterium rosenbergii. Vibrio coralliilyticus isolated from all infected coral samples may be
highly responsible for the sign of WS disease.
Conclusion, significance and impact of study
The findings of this study provide baseline data and information on
potential coral pathogens identified in the coastal waters of Tioman Island. Etiological disease study is suggested to
validate their severity and virulence factors in the future.
Vibrio--pathogenicity
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Anthozoa