Newcastle University

Coral diseases have been increasingly reported over the last few decades and are a major contributor to coral decline worldwide. The Caribbean in particular has been noted as a hot spot for coral disease and the aptly named white syndromes have caused the decline of the dominant reef building corals throughout their range. One disease in particular known as White Band Disease (WBD) has been implicated in the dramatic loss of the two most dominant corals within this region (the staghorn and elk horn coral) since the 1970s. This disease has resulted in both species now being listed as critically endangered on the IUCN Red list.

Despite this devastating effect on an entire ecosystem, the causal agent or agents remains unknown. Although recent studies have concluded that the disease is likely caused by bacteria. In this talk, I explain how our novel approach to an age old question has allowed us greater insight into this disease. Furthermore, the use of  antibiotic treatments allowed us to arrest WBD and thereby aid in the identification of the most likely pathogens of the disease.

The disease appears to be caused by an initial systemic bacterial infection followed closely by ciliate histophagy (meaning they cause the pathology of the disease). This study therefore indicates that WBD involves multiple pathogens, explaining the lack of success in identifying a single causal agent via traditionally used tests such as Henle-Koch´s postulates for over 40 years.

In addition, the talk will also cover a similar disease causing mass coral mortality in the Indo Pacific known as White Syndrome. Results show similar trends to that of WBD, but also implicate viruses into the mix. Back over to the Caribbean again and I focus on another devastating disease called Dark Spot Syndrome. Preliminary studies on this disease show that a fungus called Rhytisma is responsible for the dark pigmented lesions giving rise to the diseases name. Interestingly this fungus is implemented in a terrestrial disease called Tar Spot affecting common o garden trees like the sycamore. This is an interesting case where terrestrial plant pathogens are spreading into the marine world and could be a worrying sign of things to come.

Over the talk, I cover the good, the bad and the ugly sides of coral reefs and their microbial worlds.

This event is free, but you need to get tickets in advance.