Reef Report for Monday, April 28, 2008
Rabbitfish on the Reef, Rabbits in the outback
Grazing can be good for the Great Barrier Reef.
Recent news on the Great Barrier Reef has focused on the discovery of a potentially important role that Rabbitfish may play in maintaining healthy coral reefs in Australia.
These small, uncommon and normal looking fishing do not standout by themselves, but the work they do just might be very noticeable.
Rabbitfish are algal grazers, moving across the reefs to graze on patches of algae.
Professor David Bellwood of the ARC Centre of Excellence for Coral Reef Studies and James Cook University has been studying these animals and their role in the ecosystem. Other research has indicated that while surgeonfish, parrotfish, and batfish all graze algae, none of these seems to graze thick stands of algae.
Thick stands of algae compete with coral, both for light and for hard surfaces to attach to. Since algae grow much faster than coral, the regrowth of coral reefs can be slowed by the growth of thick stands of algae.
Rabbitfish move about the reef in small schools, and seek out thick stands of marine algae, that they quickly graze down to stubble. Researchers think the presence of rabbitfish on coral reefs are vital to grazing down algal patches, which are then kept in check by other grazing fish. Coral larvae can then colonize these areas and regenerate coral reef.
Itís kind of interesting to contrast Rabbitfish on the Great Barrier Reef with the introduction of rabbits into mainland Australia early during the colonial settlement period. While both are very effective grazers, to the point of grazing their host food down to stubble, Rabbitfish, as a native species to the Great Barrier Reef, are a keystone species whose grazing activities help maintain a healthy and diverse ecosystem. On the other hand, rabbits, and introduced species once reached plague proportions in Australia, and their grazing activities have caused major disruption to Australianís sensitive grasslands and shrublands.
Background information on Rabbitfish, from James Cook University.
News coverage of Rabbitfish, from the Brisbane Courier Mail.
A video of Rabbitfish grazing marine algae, from James Cook University.
Background information on the impact of rabbits on Australian ecosystems..
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.