Reef Report for Saturday, February 14, 2015
The Great Barrier Reefís Thorniest Problem
Iím sure that everyone who dives has heard about the Crown of Thorns sea star and the problems that population outbreaks of this animal can cause to coral reefs here in Australia.
For as many of them that there are, most visitors that dive here on the reef never see one.
Thatís because the outbreaks of these animals that are near dive sites are usually put down by a team of divers that kill them by injecting them with poison. This action can protect dive sites pretty effectively, but reef-wide protection would be impossible by this method, given the immense size of the Great Barrier Reef.
Lately thereís been some new research into control methods, including using the scent of predators of Crown of Thorns to disrupt their normal activities.
These animals, despite their destructive nature, are very beautiful. Keep in mind they are also very venomous, divers should never contact the sharp spine of these creatures, it results in a very painful and sometimes dangerous jab.
While thatís all good news, more needs to be done about reducing the nutrient levels of nutrients in the waters that drain off the land and into the Great Barrier Reef lagoon, which have been connected with increasing the survival rates of the larval stages of Crown of Thorns. Agriculture, land clearing, and urban runoff are pointed to as key causes of the nutrient level increases seen in our coastal waters.
Unfortunately, with the spectre of warmer ocean waters looming on the horizon, recent research has shown that not only does warmer ocean water create problems like acidification and coral bleaching, but appears to increase the survival rates for early life stages of crown of thorns as well.
This triple threat to the reef is going to prove difficult to manage, so a focus on lowering nutrient levels in runoff will become a very important task in the coming years.
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.