Kimberley coral spawning treats scientists to rare show

Thursday, 24 May 2012 10:00
Science Network Western Australia

CORAL spawning in the Kimberley coastline was recently first-witnessed by WA researchers, as slicks of blue and pink gametes lit the dark waters after sunset.


Dr Andrew Heyward from the Australian Marine Science Institute, who provided guidance to the KMRS leading up to the event, says observing the coral spawning is a first step in identifying the key seasonal patterns for corals along the Kimberley coast. Image:hjk_888

Recorded about 6.30pm on March 17 at the WAMSI partnered Kimberley Marine Research Station (KMRS) in Cygnet Bay, Research Officer Ali McCarthy says “the combination of natural phenomena with the wild wet season weather overhead and this remarkable spawning snowstorm under the surface was genuinely awe-inspiring.”

“We saw the first signs of spawning activity as turquoise gametes were released from the Faviid and Mussid corals and shortly afterwards, the Acroporid corals began releasing their gametes into the water and the aquariums were awash with slicks of blue and pink spawn.”

“From a scientific perspective, it was really exciting in that this was something new, not just for me or for us at KMRS, but for the greater Kimberley coastline as a whole, where it had been acknowledged that in general the finer details of spawning activity along the mainland Kimberley coast were not well studied and had not yet been observed directly for science.”

Dr Andrew Heyward from the Australian Marine Science Institute, who provided guidance to the KMRS leading up to the event, says observing the coral spawning is a first step in identifying the key seasonal patterns for corals along the Kimberley coast.

“If it turns out most corals spawn along the Kimberley at certain times of year then we can look at the currents and get a much better idea of which way the spawn will travel and hence, how connected different parts of the coast are.

“At a broader level, these initial observations at Cygnet Bay show that for some coral species at least, their reproductive patterns and timing are the same as offshore reefs in the region such as Scott Reef and the Rowley Shoals.

“As we extend these studies, it may be that the biology of corals in the region is shown to be quite similar to what we know from better studied reef areas.”

Although spawning demonstrates a time of renewal for our reef building corals, Ms McCarthy says the Kimberley corals as a whole are not well understood due to their remoteness.

“It is only in recent years that their uniqueness and high biodiversity have been explored and recognised in a western science perspective,” she says.

The observations are just a building block from which to launch further investigations and establish monitoring programs.

It is hoped the KMRS can begin to collate a series of data over time and start to fill the knowledge gaps that surround the Kimberley marine environment.