WA's remarkable mass autumn coral spawning about to begin

One of the most spectacular natural events in Western Australia - the annual mass autumn spawning of corals - will occur off parts of the coast in the last week of March.

Environment Minister David Templeman said more than 250 species of coral had been identified around areas such as the Dampier Archipelago, the Abrolhos lslands and in the Ningaloo Marine Park.  The majority of these would synchronise their reproduction to spawn on a few nights of the year.

"In WA, this means corals will generally spawn seven to 10 days after the full moon in March-April, when the weather is typically hot and balmy," Mr Templeman said.

"The mass spawning is a mechanism to facilitate successful reproduction.

"By spawning at the same time and when the water movement is minimal, corals maximise the concentration of eggs and sperm thereby increasing the chances of fertilisation.

"The simultaneous spawning of many different species at night ensures enough coral larvae survive predators which will have an excess of food over a short period."

The Minister said there already had been a minor coral spawn in February and another would be likely to occur in April.  Minor spawnings also sometimes occurred in WA in spring.

"Corals don't just all spawn on one night of the year but the main period is generally after the full moon in March-April each year," Mr Templeman said.

"This year the major period of coral spawning is predicted to occur on the nights of March 28 to 31."

Mr Templeman said if coral spawning occurred in extremely calm weather, the spawning could be so dense that it effectively 'choked' the surrounding waters leading to massive numbers of fish dying as a result of a lack of oxygen.

The coral spawning also coincides with the arrival of the whale sharks that feed on microscopic organisms.

Minister's Office - 9220 5050