The effect of allometric scaling in coral thermal microenvironments
MetadataShow full item record
A long-standing interest in marine science is in the degree to which environmental conditions of flow and irradiance, combined with optical, thermal and morphological characteristics of individual coral colonies, affects their sensitivity of thermal microenvironments and susceptibility to stress-induced bleaching within and/or among colonies. The physiological processes in Scleractinian corals tend to scale allometrically as a result of physical and geometric constraints on body size and shape. There is a direct relationship between scaling to thermal stress, thus, the relationship between allometric scaling and rates of heating and cooling in coral microenvironments is a subject of great interest. The primary aim of this study was to develop an approximation that predicts coral thermal microenvironments as a function of colony morphology (shape and size), light or irradiance, and flow velocity or regime. To do so, we provided intuitive interpretation of their energy budgets for both massive and branching colonies, and then quantified the heat-size exponent (b*) and allometric constant (m) using logarithmic linear regression. The data demonstrated a positive relationship between thermal rates and changes in irradiance, A/V ratio, and flow, with an interaction where turbulent regime had less influence on overall stress which may serve to ameliorate the effects of temperature rise compared to the laminar regime. These findings indicated that smaller corals have disproportionately higher stress, however they can reach thermal equilibrium quicker. Moreover, excellent agreements between the predicted and simulated microscale temperature values with no significant bias were observed for both the massive and branching colonies, indicating that the numerical approximation should be within the accuracy with which they could be measured. This study may assist in estimating the coral microscale temperature under known conditions of water flow and irradiance, in particular when examining the intra- and inter-colony variability found during periods of bleaching conditions. © 2017 Ong et al.
Showing items related by title, author, creator and subject.
Ong, R.; King, Andrew; Caley, M.; Mullins, B. (2018)© 2018 Light distribution on coral reefs is very heterogeneous at the microhabitat level and is an important determinant of coral thermal microenvironments. This study implemented a solar load model that uses a backward ...
Coscinaraea marshae corals that have survived prolonged bleaching exhibit signs of increased heterotrophic feedingBessell-Browne, P.; Stat, Michael; Thomson, D.; Clode, P. (2014)Colonies of Coscinaraea marshae corals from Rottnest Island, Western Australia have survived for more than 11 months in various bleached states following a severe heating event in the austral summer of 2011. These colonies ...
Prediction of surface warming in corals using coupled irradiance and computational fluid dynamics modellingKing, Andrew; Mullins, Benjamin; Ong, R.; Caley, M. (2011)The WWF estimates that coral reefs are responsible for almost $30 billion USD net benefit to world economies. However, these reefs are under threat from coral bleaching, events which are have been a regular occurrence ...