A citizen science project in the Indian Ocean Territories (IOT) Marine Parks funded by Parks Australia has just produced some novel and important data to assist in the conservation and management of the IOT. Following a training workshop run by Professor Andrew Baird and Dr Jean-Paul Hobbs from James Cook University on Christmas Island in September 2023, Hamasan and Lin of Wet’n’Dry Adventures have been surveying the staghorn corals for imminent signs of spawning, specifically mature eggs (Fig. 1). Until now, it was not known when the corals on Christmas Island spawned.

The surveys have established that in Flying Fish Cove, the spawning season extends over at least three months with some spawning predicted to have occurred following the full moons in early October, November and December 2023 (Fig. 2).

Interestingly, similar surveys on Cocos Island over the same time interval have yet to find any mature eggs, suggesting the staghorn corals on Cocos spawn at a different time of year to those on Christmas. This was not expected given the relative proximity of the islands and the fact that they lie on a similar latitude. The surveys on both Christmas and Cocos will continue to establish when the staghorn corals spawn and ultimately allow us to work out what environmental variables are driving these patterns.

We thank Parks Australia for funding the workshop and ongoing surveys of coral reproductive condition in the IOT.