Festival of love under a November moon
by Ben Edwards
Preparations have begun for a festival of free love to rival the Gay and Lesbian Mardi Gras. For a few consecutive November nights, in the wake of a full moon, heterosexuals and hermaphrodites alike will engage in a symphony of sexual liberation.
It was in second year Invertebrate Biology, when I first learned about the sexual exploits of coral, that my passion for science was ignited. Not only are coral animals like you and me, some of the little critters also have the ability to reproduce sexually in a spectacular ritual known as mass spawning.
The girl coral get busy producing millions of eggs up to six months before the November full moon, while the lads are prolifically producing sperm. Hermaphrodite coral have the added burden of producing both gametes.
The culmination is en masse release of sperm and eggs closely linked to water temperature and lunar activity. Although difficult to predict, spawning can occur between two and six nights after the November full moon.
The full moon reduces tidal movement allowing sperm and eggs to congregate for long enough to get it on. Those that escape the predator’s jaw go on to form free swimming offspring before settling to create a new reef colony.
Divers lucky enough to witness the festivities may be excused for thinking that life as a coral is all sex, drugs and rock’n roll. The release of eggs packaged in pink capsules by female coral has been described as having the appearance of champagne bubbles, while the males appear to be smoking as they release their little swimmers.
Warm water, a full moon, sex, champagne and smoking. Sounds like a scene from Boogie Nights. Some readers might be thinking that life as a coral appears more appealing than ever. However, given that such frivolity only occurs once a year, most would choose to leave the mass spawning to our marine friends.
The coral of the Great Barrier Reef is approximately 500,000 years old. (Relatively young considering coral reefs have existed on earth for 500 million years.) The reef has survived changing global climate caused by cycles of glacial advance and retreat, but despite this a recent report from the University of Queensland’s Centre for Marine Studies predicts that the Great Barrier Reef will lose 95 per cent of its living coral by 2050 due to global warming.
Certainly changing global temperatures is one of the major challenges facing the planet today. However, it is unlikely that the coral of the Great Barrier Reef will be decimated by the middle of the century. Further research is required to determine the extent of global climate change and its impact on coral reefs.
Meanwhile, the raunchy little coral are free to continue their annual festival of love under the ambiance of the November moon.