The Great Barrier Reef and the Coral Sea (1 of 5)
As expected, one of the highlights of the trip was the diving and snorkelling daytrip we took on board the TUSA IV out of Cairns. A number of the students had become scuba certified especially for this trip and were able to make several dives on the reef with me as a guide. The remainder of the students snorkelled with Paddy Calwell, a local reef activist and educator. I took an underwater camera along for the trip and was able to record a number of images. I have also included some photos I took while on a 4-day trip out to Holmes Reef in the Coral Sea.
Coral Reefs are unique ecosystems that are among some of the the most diverse in the world. They are also largely self sustaining, that is, with the exception of sunlight for photosynthesis and some waterbourne minerals for the formation of limestone skeletons, they do not really require the input of energy in the form of food. This means that each animal or plant is in balance with all other organisms in the reef and that any disturbances such as the removal of fish by humans, can have catastrophic effects on the health of the reef. The Australian government has created the Great Barrier Reef Marine Park Authority to oversee the continued health of the reef and to manage it for future generations. All activity on the reef, be it diving, fishing etc is closely monitored for its effect upon the reef.
Coral Polyps from the family Xeniidae, possibly Xenia sp.
BigEye Trevally (Caranx sexfasciatus) swirling around a coral pinnacle at Holmes Reef in the Coral Sea.
A Shaded Batfish (Platax pinnatus) taking refuge among some staghorn coral (Acropora sp.) at Flynn Reef on the GBR.
A serious problem on the GBR these days is coral bleaching. This is apparently the result of global elevations in water temperature causing the coral polyps (animal) to expell the symbiotic zooxanthellae (plant) responsible for photosynthesis. This coral (Acropora sp.)has undergone partial bleaching so far...the rest is surely not far behind.
Top : Ashley at the bar. At the end of each dive, we would spend 3 to 5 minutes at 15 feet at a safety stop, in this case a bar suspended beneath the boat. The safety stop is designed to allow the body to offgas some of the nitrogen that it absorbed while breathing air at pressure under the water. All of us used sophisticated dive computers to monitor the levels of nitrogen in our bodies that resulted from the dives. Bottom: Laura at the bar too!
Ashley and Laura sit on the bottom at about 50 feet and play with one of the locals, a sea cucumber.