Quantifying rates and trends in endolithic bioerosion on coral reefs

The production and build-up of the carbonate framework structure of tropical coral reefs is controlled by the rate of calcium carbonate (CaCO3) production (driven mostly by corals) relative to the rate at which a range of physical, chemical, and biological erosional processes remove carbonate. Whilst our understanding of carbonate production rates has increased significantly in recent years, data on biological erosion rates is more limited, and is especially sparse for highly cryptic microendolithic boring taxa. This is a major knowledge gap given the increasing availability of reef substrate for bioeroder exploitation as coral cover levels on reefs decline. The overarching aim of this research is thus to expand on our presented limited understanding of microbioerosion on reefs and specifically to investigate how microbioerosion rates vary between reefs and within reefs and to assess the control of coral substrate on euendolithic community composition and microbioerosion rates. As outlined above significant knowledge gaps in relation to these issues exist globally, and thus the focus in this research has been to address specific areas relevant to one or more of these research priority areas. These gaps will be addressed through three primary objectives: O1. To address major biogeographic gaps in microbioerosion rate data; O2. To assess how microbioerosion rates vary between proximal sites with different turbidity and/or across depth gradients within sites; and O3. To address differences in microbioerosion rates and euendolithic community composition between different coral substrate types (i.e., by taxa and structure). The project involves a supervisory collaboration between staff at U. Exeter, the Natural History Museum London, and U. Queensland, Australia.