jaybee
14-07-2004, 05:55 PM
Courier Mail News
Michael Madigan
13jul04
FISH on the Great Barrier Reef soon may live almost as long as the average human – and they won't be letting the autumn years slow down their sex lives.
Scientists yesterday revealed some reef fish could have a life span of 60 to 70 years.
They have found a coral trout which evaded dinner plates for 19 years and a red throat emperor thriving in his 25th year.
And rather than allowing age to slow down their reproductive capacity, mature-age fish are producing far stronger children than their youthful counterparts.
The revelations, made yesterday at the third International Symposium of Fish Otolith Research and Application in Townsville, are expected to impact heavily on how we manage fish stocks.
"From a fishery management perspective, it will become important for us preserve the older fish," conference chairman Gavin Begg said.
Dr Begg, of the CRC Reef Research Centre at James Cook University, said decade-old research on fish age in Queensland was producing amazing data.
Age is determined by examining the "otolith" – the ear bone used by fish for balance and orientation. The otolith lays downs rings, much as a tree does, and allows scientists to accurately determine birth dates.
It was previously believed the absence of significant change in sea temperature in the tropics would prevent accurate otolith assessments.
"We have found that is not the case, and we are now coming up with a lot of accurate information," Dr Begg said.
Even small cod, previously thought to live only a few years, are reaching 30 to 40.
With Great Barrier Reef Marine Park Authority green zones now banning fishing, it was possible some reef fish such as red bass would make 60 or 70.
Scientists working overseas have found deepwater fish living to 100 years and more.
And these older fish were found to be producing more eggs the older they got, Dr Begg said.
"With more spawning experience they tend to produce larva that is larger and stronger and has more chance of survival."
Michael Madigan
13jul04
FISH on the Great Barrier Reef soon may live almost as long as the average human – and they won't be letting the autumn years slow down their sex lives.
Scientists yesterday revealed some reef fish could have a life span of 60 to 70 years.
They have found a coral trout which evaded dinner plates for 19 years and a red throat emperor thriving in his 25th year.
And rather than allowing age to slow down their reproductive capacity, mature-age fish are producing far stronger children than their youthful counterparts.
The revelations, made yesterday at the third International Symposium of Fish Otolith Research and Application in Townsville, are expected to impact heavily on how we manage fish stocks.
"From a fishery management perspective, it will become important for us preserve the older fish," conference chairman Gavin Begg said.
Dr Begg, of the CRC Reef Research Centre at James Cook University, said decade-old research on fish age in Queensland was producing amazing data.
Age is determined by examining the "otolith" – the ear bone used by fish for balance and orientation. The otolith lays downs rings, much as a tree does, and allows scientists to accurately determine birth dates.
It was previously believed the absence of significant change in sea temperature in the tropics would prevent accurate otolith assessments.
"We have found that is not the case, and we are now coming up with a lot of accurate information," Dr Begg said.
Even small cod, previously thought to live only a few years, are reaching 30 to 40.
With Great Barrier Reef Marine Park Authority green zones now banning fishing, it was possible some reef fish such as red bass would make 60 or 70.
Scientists working overseas have found deepwater fish living to 100 years and more.
And these older fish were found to be producing more eggs the older they got, Dr Begg said.
"With more spawning experience they tend to produce larva that is larger and stronger and has more chance of survival."