Tropical Cyclones in the Great Barrier Reef, Australia, 1910-1999: a First Step Towards Characterising the Disturbance Regime

The proximity of a reef to a tropical cyclone path is the simplest means of estimating the potential for disturbance (that is, physical damage from waves) at that reef. Calculated for cyclones that tracked across a sample of reefs spanning much of the Great Barrier Reef (GBR) from 1910 to 1999, such proximities provide a preliminary history of cyclone disturbance in that region for which spatial and temporal trends can be examined. As the long-term dynamics of cyclone disturbance affect the structure and function of coral reef communities, the disturbance regime can be used to consider whether the current state of coral communities (as measured in 1999) represents that which was present over the entire time series, and whether the frequency of cyclone disturbance across the GBR is high (limited recovery time between events) or intermediate (variable recovery time between events) in nature. This analysis reveals that for more than half of the GBR, the latest major disturbance occurred less recently than normal for the time series (current communities had more time for recovery than usual) and that these disturbances are generally intermediate in frequency. However, because many factors other than distance affect the potential for disturbance, these results represent a first step towards characterising the nature of cyclone disturbance across the GBR.