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View Full Version : Gropers aren't the only oldies having fun



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."

jeffo
15-07-2004, 01:51 AM
interesting! :o
looks like there may be a few more maximum size limits comming into play. :)

baldyhead
15-07-2004, 07:14 AM
I believe that there should be MAXIMUM size limits to all species of fish regardless.
Cheers

firetruck
15-07-2004, 07:35 AM
I tend to agree baldy.

Daintreeboy
15-07-2004, 01:54 PM
I like the one how a green zone will allow the Red Bass to reach 70 years old. ROFL good one, we'd all keep Red Bass otherwise wouldn't we boys? ;D

MTpockets
15-07-2004, 03:30 PM
Yep, I like the idea for max sizes, as long as its not silly. I can see some varieties becoming untouchable maybe, due to size restrictions. Hope they get it right....
cheers
Les

CHRIS_aka_GWH
15-07-2004, 03:48 PM
why - when some fishes sex are not determined at all by size or age.

I'm for it if there is a just scientific reason that will help ensure the sustainablilty of a population & importantly other populations in its food chain (something often overlooked in these discussions).

We are yet also to prove the sustainability of maximum sizes in a saltwater environment. Short term its working well for flathead. What happens in a couple of decades when the big breeders die through natural attrition & the increased pressure on the small size fish means fewer reach their breeding potential ?

We are fools not to try though.