North Australian FISH FINDER TM forums

Some interesting data here re predicting barramundi stocks vs actual outcomes. Data is from Infofish Australia, with the full report attached as a PDF. While the info is for Qld's Gladstone region, it will be of interest to NT fishos.

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Fish in the “Crystal Bowl”

The “Crystal Bowl” is a unique process developed in Central Queensland for the prediction of Barramundi stocks, covering the Fitzroy River and Gladstone areas.

This week the Crystal Bowl gained international recognition at the EIFAAC International Symposium on Recreational Fisheries held in Lillehammer in Norway. It was the only Australian presentation at the conference and was reported as being an invaluable contribution to the conference.

The presentation at the conference coincided with the release of the 2015 mid-season Crystal Bowl review of Barramundi stocks. The review indicated that most predictions were close to the mark. The catch rate for legal sized Barramundi in the Fitzroy River was predicted to be down 30-50%. The commercial catch for the start of the season was down 37% and for recreational fish taggers was down 43%.

For Gladstone the catch rate for legal sized fish was also predicted to fall 30-50%. There was no change in the commercial catch for the start of the season while for recreational taggers the catch rate was down 40%. It is expected that the commercial catch rate may be better than predicted as more large Barramundi left Lake Awoonga when it spilled in Jan-Mar and ended up in the Boyne River and Gladstone Harbour.

Infofish Australia manager Bill Sawynok and leader of the Crystal Bowl project said that catch rates were down this year due to harvest levels by commercial and recreational fishers exceeding the numbers of new recruits entering the fishery over the past 3 years. He said catch rates for 2016 are expected to fall further.

“However the good news is that recruitment, the numbers of baby Barramundi, this year is the third best in the past 15 years, one positive contribution from Cyclone Marcia. These fish will reach legal size in 2018," Mr Sawynok said.

"The bad news is that 2016 is likely to be the toughest year since 2007 for legal sized fish in the river.” Mr Sawynok added.

The news for Gladstone is better in that 75% of Barramundi there are over legal size compared with 13% in the Fitzroy River as caught by recreational taggers.

Mr Sawynok said our ability to predict fish stocks is still improving and not quite in the class of weather predictions but we are working on improving the accuracy and reliability of the forecasts.

“Commercial and recreational fishers can use the information from Crystal Bowl with some confidence to determine the level of investment they want to make in catching Barra."

Bill Sawynok, Infofish Australia Manager