NEW research into the age and growth of mangrove jacks in NSW has established that the species can live to a ripe old age.
In the research conducted jointly by NSW DPI and Southern Cross University and funded by the Recreational Fishing Trust, the oldest fish aged in the study was 57 years old and measured 826mm fork length, making it the oldest jack, and the oldest individual from the family Lutjanidae, yet aged worldwide.
Other large jacks aged during the project ranged from 20-52 years of age which were between 730-1019mm fork length.
All of these big jacks were reportedly sampled from offshore reefs. In contrast, the oldest mangrove jack from an estuary was aged eight years old and measured 584mm.
The jacks were aged by counting growth rings in thinly-sectioned otoliths, or ear bones.
Importantly, this research would not have been possible without the involvement of anglers and spearfishers who donated nearly 200 jack frames over two years.
Check out the Mangrove Jack Project on Facebook.
