TAFI Abalone Section Leader Craig Mundy said the program had been very successful and researchers had managed to collect some exciting data.

"This is very much long-term study - it may be four or five years before we start to see some clear and repeatable results, but it is important that this basic research is done," he said.

"We are having to think outside the square with our approach to this as abalone are very cryptic - until they reach a certain size, you don't normally see them, you can't count them and really you don't know if they are even there.

"Until they are four to six years old, the juvenile abalone do not come out of hiding. Often they do not emerge until just before the size at which they enter the fishery."

Dr Mundy said if abalone are being overfished or if some major environmental change affected the numbers of small abalone, it could be several years before the full impact on the population would be realised, by which time it could be too late to do anything about it.

"There would be no time to adjust the quota," he said. "So there is a strong desire amongst the fishers in the industry to know about juvenile numbers."

"What we have been doing over the past five days is diving in six main periods - before sunrise, after sunrise, midday, before sunset, after sunset and midnight - searching for juveniles," he said.

Dr Mundy said the researchers know from work on abalone farms and from anecdotal information from divers, that the button-size juveniles are most active at night.

TAFI researchers are using the information on juvenile activity to design artificial habitats -which duplicate the habitat favoured by juveniles. The artificial habitats were put in place this week.

These habitats will be used to provide an index of juvenile abundance at several sites to determine the relationship between the density of juveniles and the number of harvestable animals present several years later.

"Knowing the abundance of juveniles could provide a three to four year advanced warning of fluctuations in the population and would be an extremely valuable management tool," Dr Mundy said.

Tasmania's abalone fishery is one of the first to meet the Australian Government’s sustainability standards, having demonstrated that it is managed in an ecologically sustainable way, and is therefore exempt from the export controls of the Environment Protection and Biodiversity Conservation Act 1999.

The value of the Tasmanian abalone industry was AUD 129 million last year.

By Helen Roberts
FIS.com

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