LADY MUSGRAVE IS

This reef has been surveyed extensively since 1986. Reef-wide live coral cover dropped dramatically between 1988 and 1990. Evidence suggests strong weather in the region during this time may have partly influenced this decline. Coral cover continued to decline until 1993 before showing a clear trend of recovery. Although COTS have been recorded on this reef on a number of occasions they have not been in high enough numbers to affect reef-wide live coral cover. Reef-wide coral cover is presently very high (50-75%) and the reef is classified as No Outbreak. No bleaching was observed on this reef during manta tow surveys in 2003. White Syndrome Disease was generally at low levels (restricted to a few individual coral colonies) however it was common (more than 10 colonies per two-minute tow) on the first flank of Lady Musgrave Island Reef where coral cover was the highest.

Detailed benthic surveys conducted on the northern flank show that hard coral cover has increased exponentially from less than 5% in 1993 to a very high level (65%) in 2000. Cover of tabulate Acropora has increased dramatically from 0% in 1993 to 57% in 2000. Historical records indicate that dominance by tabulate Acropora is typical for reefs in this region. Soft coral cover is low (< 1%). The decrease in algae cover to 32% in 2000 corresponds to the increase in hard coral cover. The lack of current abundance increases or decreases in all but two of the reef fish families or genera reflects the fact that fish assemblages have tended to stabilise after a period of general increases, which tracked hard coral recovery following benthic community declines in the late 1980'S. Numbers of the genus Chromis and , Neopomacentrus (essentially , N. , azysron) have tended to decrease since 1998/99. Abundance of the genus Pomacentrus has declined over recent years due to P. coelestis which recruited in comparatively large numbers in the first years post-disturbance and then declined. The lack of any current trend in this genus reflects the fact that numbers of P. coelestis are now within the range of other Pomacentrus species; a number of which have increased in abundance.

Lady Musgrave Is (No. 23-082) is an outer shelf lagoonal reef with an area of 12.5 sq.km. Last surveyed September 2002.







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