Reef Report for Thursday, March 1, 2007
Crown-of-thorn Outbreak not Currently a Threat to the Reef
Recent surveys find very few coral-eating starfish.
In January of 2007 a series of surveys were taken on reefs in the Northern Great Barrier Reef by the Australian Institute of Marine Science (AIMS). In announcing results of the survey, part of a long term reef monitoring program, AIMS project leader Dr Hugh said.
"Since the crown-of-thorns starfish first came to public attention in the 1960s, new waves of outbreaks have appeared in the region north of Cairns about every 15 years, (However) our recently completed surveys targeting northern, mid-shelf reefs detected only three crown-of-thorn starfish on 43 reefs."
No outbreak of crown-of -thorn starfish is imminent, which is good news for the reefs. There have been outbreaks of these coral eating starfish going back thousands of years, so these animals have helped shape the reef to make it such a wonder, scientists are concerned that that these outbreaks may have become more frequent in the past 200 years, and that this increased amount and frequency of the disturbance caused by these animals may make the reef less diverse, and disrupt the delicate balance in this unique ecosystem.
The way these surveys are done is interesting, as pictured here; a diver is taken on a "manta tow". The diver controls their direction and depth using the planning board, as the boat tows them at a constant rate of speed over the reef. A count is made while being towed, and the results of these counts are compared with those of tows made in previous years.
The long term monitoring of coral reefs is essential to understanding the processes that are affecting the health of the reef, and to record the changes that are taking place in the reef. You can read more about the project and view the results here. We find the reef by reef survey results and descriptions.very interesting, and have use them ourselves to identify the reefs we want to visit on future dive trips.
Results of the recent survey..
Long term Reef Survey results, sorted by reef name..
Coverage of this story by Nine/MSN.
The weekly reef report is written by Joel Groberg of DiveTheReef.com,
who compiles them from the many conversations he has with dive staff in the area, as well as many other local sources in the dive
Index of all reef reports.