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GBR - Large-scale manta tow surveys of densities of crown of thorns starfish and benthic cover by the AIMS LTMP

Posted on 28 January 2009

The purpose of this study is to quantify spatial and temporal changes in the density of crown-of-thorns starfish and benthic cover in the Great Barrier Reef. Broad-scale manta tow surveys have been conducted by the Long-Term Monitoring Program (LTMP) of the Australian Institiute of Marine Science since 1986, counting crown-of-thorns-starfish (COTS, Acanthaster planci).

COTS densities fluctuates over years forming southward bound ‘waves’ (the incidence of reefs with new active outbreaks moving south over time, due to the southward transport of larvae by the East Australian Current). Outbreaks in the Swains sector appear to occur independently of the main southward moving wave of COTS outbreaks. The highest overall mean number of COTS per tow was 1.17 in 1988. Active or incipient outbreaks were recorded on 16% and 11% of the reefs surveyed reefs in 2004 and 2005, respectively. The highest percentage of reefs with active outbreaks was 17%, recorded in 1987, 1999 and 2000.

Benthic cover of hard corals, soft corals and dead corals was also estimated on each tow, providing comprehensive estimates of cover around the whole perimeter of reefs.

Reports of the latest survey can be viewed online within 3 weeks of completion of field work:


  • Hugh Sweatman (AIMS)
  • Australian Institute of Marine Science
Owner Institution(s)

Crown-of-thorns starfish: number of starfish per transect;

Benthic cover: percent.

Data Units
Great Barrier Reef (whole GBR).
Region & Spatial Extent
1986 - 2005
Data Collection
Maintenance & Update Frequency
Copyright remains with the data owners.
Resource Constraints
  • Bass D.K. & Miller I.R. (1996) Crown-of-thorns starfish and coral surveys using the manta tow and SCUBA search techniques. Standard Operational Procedures Number 1, AIMS, Townsville.
  • Sweatman H., Burgess S., Cheal A., Coleman G., Delean S., Emslie M., Miller I., Osborne K., McDonald A. & A T. (2005) Long-Term Monitoring of the Great Barrier Reef Status Report Number 7. In. Australian Institute of Marine Science, Townsville.
Dataset Short Name
Google Earth Data