Reef Report for Friday, March 7, 2003
Hard Corals Abound on the Reef
As a follow up to last weeks article on corals found here I thought I would write about two types of hard corals (scleractinians, being the scientific name) that are regularly seen on the reef, Brain Coral and Staghorn Coral.
Brain Corals are described as massive coral colonies, which on average grow 1-3 cm a year. Brain corals polyps divide without forming complete walls around themselves and thus create elongated lines of mouths living in a skeletal pattern of ‘valleys’ separated by ridges. Red brain coral is one common species on the reef, and it’s common name accurately describes it. definition.
Staghorn corals (Acropora sp.) are branching corals, which on average can grow 3-10cm per year, making it one the faster growing hard corals found here. These colonies have thick, elongate, conical branches standing vertically toward the centre of the colony, with branches of the colony margin thinner, shorter and mostly horizontal. Colours can be of green or brown with cream pr pink branch tips. There are a number of different species of staghorn corals, so the next time you go diving or snorkeling on the reef tray and see how many different types you can spot.
Out on the reef this week operators reported some great sightings.
Weather conditions changed from day to day due to the NNW winds for most of the week, which do not make for the best diving or snorkeling conditions on the reef. Still, passengers reported to be very happy overall.
Reef Magic Cruises went to the lagoon at Thetford Reef, which provided excellent conditions though the Northwest winds started to increase during the afternoon. All the local residents came to say "G'day", including a Spangled Emperor, red bass and many others. Certified divers had a fantastic dive at the pinnicales with underwater visibility of 25 metres. Reef Magic Cruises also visited Milln Reef, which produced underwater visibility of up to 30 metres, blue sky all day and fantastic corals and prolific fish life.
Divers on Scubapro this week were stunned when on three different dives they spotted a Manta Ray. Also a large Queensland Grouper graced divers with its presence at Milln Reef.
The winds this week saw passengers on board Diversity dive some rarely dived sites along the southern wall on Osprey reef. Divers encountered a number of large 3m silver tipped reef sharks as well as a school of male Maori wrasse. The large tides experienced on the trip made for some great drift dives especially around ‘dynamite pass’ at Osprey Reef.
This weekend is not sounding the best diving or snorkeling conditions due to Cyclone Erica. It is predicted that the cyclone will be well off the Tropical Coast by the weekend but there will be rain and a strong winds. The best thing to do is check each morning with the weather bureau before making your decision. So whatever you decide to do this weekend, make it fun and as always be safe! Steve Brady
This weekly reef report was written by Steve Brady of Pro Dive Cairns, who compiles them from the dive trips he takes, as well as the many conversations he has with divers, dive instructors, captains, and others in the Cairns dive community. The report is published weekly in the Cairn Post, the local daily paper and appears here thanks to the courtesy of
Pro Dive Cairns.
Index of all reef reports.