Publication Abstract

Coral reefs in turbid waters: Sediment induced stresses in corals and likely mechanisms of adaptations

By K.R.N. Anthony and P. Larcombe

Coral reefs close to the shoreline may repeatedly be exposed to high concentrations of suspended sediments and low light levels, but many such reefs display high coral cover, indicating that the corals have become adapted or acclimated to such events. Here, we discuss a set of mechanisms by which corals might adapt or acclimatise to variable sedimentation and turbidity. Specifically, we note the documented links between key physical parameters in turbid habitats (e.g. turbidity and suspended sediment concentration (SSC), light extinction, grain size and composition) and predicted responses of coral photosynthesis, feeding and respiratory/excretory losses. Based on observed temporal patterns in turbidity and sedimentation, we argue that 1) rapid replenishment of energy reserves during periods between sublethal turbidity events, 2) shifts between phototrophic and heterotrophic dependence, and 3) rapid rates of photo-acclimation are likely mechanisms by which corals maintain a positive energy balance (a proxy of stress or health) on coral reefs in turbid zones.

Reference:

K.R.N. Anthony, P. Larcombe. 2003 Coral reefs in turbid waters: sediment-induced stresses in corals and likely mechanisms of adaptation. Proceedings of the ICRS, Bali, October 2000, 239-244.