On the island of Saint Lucia, the spawning event occurs only annually and over the course of just two nights. If that wasn't specific enough, it lasts just one or two hours and even then is intermittent and never guaranteed to take place. What triggers the natural event is still not completely understood. Marine biologists speculate that perfect combinations of the tides, lunar cycle and water temperature could have a bearing on the phenomenon. In certain places around the world it has been possible to predict by monitoring the lunar cycle.
We enter the water on the first evening when the spawn has been predicted at 20:30 and in the dark. On night two, it's the brittle star's turn and always happens in this sequence.
Both the coral and the brittle stars are sensitive to light and won't spawn if subjected to too much torchlight. Therefore, we wait on the reef submerged and allow our eyes to adjust to the darkness. Only occasionally do we scan the reef and water column with our torches, looking for signs of spawning.
The brittle star is even an more fickle critter, very light shy and capturing one in full spawn mode takes patience and some luck. Usually flat, leggy creatures, prior to spawning they find a high place on the reef to stand up on their legs and then release a puff of red spawn into the dark water.
In my opinion, if there was ever a symbol of the fragility of our oceans, then this has to be it.