The Impacts of Pollution on the Coral Holobiont and Risk of Black Band Disease
Geology, University of Illinois at Urbana Champaign, Urabana, IL, USA
Montastraea annularis a framework-building coral, is abundant throughout the Caribbean Sea. The M. annularis holobiont (all living and non-living coral components) is negatively impacted by increased exposure to anthropogenic pollution, leading to increased susceptibility to black band disease. M. annularis' coral holobiont is weakened with increased exposure to human sewage and ship bilge pollution, characterized by changes in the coral skeletal (decreased density, and altered structural banding), tissue (decreased zooxanthellae, and chromatophore density and increased mucocyte density), and microbial components (decreased diversity and a shift in metabolic activity), increasing susceptibility to invasion by microbes and viruses associated with coral black band disease etiology. Healthy and diseased colonies, at 5 m water depth, will be sampled from the back-reef of a protected fringing reef off Curacao's southern coast. A unidirectional current flows toward the NW past the city of Willemstad, a large point source of sewage and bilge pollution. This creates an ideal setting for in situ experimentation that quantitatively tracks the impact to coral health along a seawater pollution gradient. Our lab has established laser scanning microscopy for 3-dimensional quantification of zooxanthellae, chromatophores and mucocyte tissue density. X-ray microcomputed tomography will be used for analysis of skeletal density, and terminal restriction fragment length polymorphism analysis will be used to evaluate microbial communities. Results will be used to determine how components of the coral holobiont respond to increased levels of anthropogenic pollution, and thus better predict how these physiological responses influence the development of black band disease in corals globally.
AAPG Search and Discovery Article #90199 © 2014 AAPG Foundation 2014 Grants-in-Aid Projects