Reef Report for Monday, August 14, 2006
High Tech Crocodiles
Satellite Tracking Used to Study Salt Water Crocodiles
Itís well known that Saltwater Crocodiles move around. Until recently not many studies had been done on movements of crocodiles, but observations by scientists and local residents have constantly confirmed that crocodiles move about.
While crocodiles of any significant size are removed from the Cairns region, every so often one shows up unannounced.
As of this writing thereís a small one, perhaps a metre long, in one of the ponds in a public park in Cairns, and rangers are busy trying to remove it before it grows bigger and becomes a potential problem. Itís presumed to have found its way there by moving up from the ocean via a small creek nearby. A golf course in Port Douglas currently has a couple of new residents, a couple of crocs that have found the water hazards inviting. Movements like this are common, and if the crocodile is of any significant size itís quickly removed.
New technology has allowed for more detailed research to be done. A consortium of scientists at local universities, with major assistance of the Steve Irwin (better known as "the crocodile hunter") and his team from The Australia Zoo have been busy the past few years with this technology.
The technology consists of a small battery powered radio transmitter, which sends a signal thatís picked up by satellites. The location of the signal can them be fixed, and the movements of the crocodile can then be plotted.
The difficult part of the research involves placing the transmitter on a large, aggressive, toothy and uncooperative crocodile. Steve Irwinís team, which has been catching crocodiles for some time, has provided essential support for this task, as their knowldege of safe capture techniques is reknowned.
Once the crocodile is caught and immobilized the transmitter is glued onto the back of the croc, and will remain there for some months, until it falls off, and is so small its presence is not noticed by the animal.
With these transmitters, much has been learned about the daily and seasonal movements of crocodiles, as well as their ability to return to locations hundreds of kilometers away. One crocodile was even tracked making a 5km shortcut, traveling over dry land between two river systems.
With recent improvements in technology itís even been possible to record underwater activities of crocs, measuring the amount of time that crocodiles spend underwater, and to what depths.
Itís hoped that all this new knowledge will help protect both crocodiles and humans that venture into crocodile habitat. In the meantime, when you visit northern Queensland, be sure that you are croc smart, and follow the guidelines of the National Parks and Wildlife Service.
For More Information:
Croc Satellite tracking study in Weipa
Nesbit River Crocodile Tracking study and photo gallery
Crocodile Tracking by Satellite, a full scientific report
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.