Program 1: Regional Environmental Status

PROJECT 1.6: CROWN-OF-THORNS STARFISH

(Dr B Lassig; Mr U Engelhardt, [from February 96], GBRMPA)

Udo Engelhardt, Chris Crossland and Ian McPhail (left to right) aboard Ocean Spirit II in February, at a media conference held at Arlington Reef, off Cairns, to announce the fresh outbreak of Crown-of-thorns starfish.

Work in this Project strengthened indications of present and imminent outbreaks of Crown-of-thorns starfish. In a sample of 22 reefs in the Cairns Section of the GBRMP, there were widely dispersed active outbreaks of mature Crown-of-thorns starfish at seven reefs, localised high densities of adults at another eight reefs, and high proportions of juvenile starfish at many of the reefs. Spines and tissues for genetic analysis were collected from 1000 starfish at six of these reefs. These were analysed to see whether recruits for different years and reefs were genetically distinct (indicating different parent populations), and the results will be analysed and reported next year. A public information and extension program received ~500 reportings of starfish activity which complemented and were consistent with the researchers' survey results. A full colour information brochure was produced and widely distributed.

Detailed study of a large population at Lizard Island provided reliable protocols for identifying and ageing individual starfish and established that mark, release and recapture techniques, along with sequential estimates of coral cover and composition, can provide reasonable estimates of local starfish population dynamics and their impacts on the reef.

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