Relationship between elemental concentration and age from otoliths of adult snapper (Pagrus auratus, Sparidae): implications for movement and stock structure
A. J. Fowler A C , B. M. Gillanders B and K. C. Hall AA South Australian Research and Development Institute, PO Box 120, Henley Beach, SA 5022, Australia.
B Southern Seas Ecology Laboratories, Darling Building DP418, School of Earth and Environmental Sciences, University of Adelaide, SA 5005, Australia.
C Corresponding author. Email: fowler.anthony@saugov.sa.gov.au
Marine and Freshwater Research 56(5) 661-676 https://doi.org/10.1071/MF04157
Submitted: 13 July 2004 Accepted: 9 March 2005 Published: 24 July 2005
Abstract
The present study investigated the stock structure of snapper (Pagrus auratus) in South Australia, and the extent to which this is influenced by adult movement. Fish from the 9+ age class were sampled from six different regions, encompassing >2000 km of coastline and different habitat types. The chemistry of transverse sections of otoliths was sampled using laser ablation inductively coupled plasma-mass spectrometry, providing elemental profiles that were related to age for the first nine years of the fish’s lives. The age-related annual averages for both 88Sr and 138Ba differed significantly between regions. They were, however, similar for the first three years, then diverged considerably between the ages of three to five years, and then remained consistently different through to the age of nine years. This suggests that all fish, regardless of where captured, originated from only one or two nursery areas, but dispersed throughout the different regions between the ages of three to five years, before becoming resident to their new regions of occupancy. Thus, this population of snapper represents a single, large, stock where the individuals have a common origin, but through age-related emigration ultimately disperse and supplement the low abundance populations in regional State waters.
Extra keywords: barium, laser ablation inductively coupled plasma-mass spectrometry, strontium.
Acknowledgments
Several people provided assistance at various stages through the project, to whom we gratefully extend our thanks. Paul Jennings and Bruce Jackson assisted with the early morning starts to help collect the snapper otoliths. Bruce Jackson also maintained the database and otolith collection from which the appropriate otoliths were selected. Paul Jennings prepared the TS sections that were sampled in the analyses. Travis Elsdon and John Tsiros both provided advice on the laboratory procedures associated with the chemical analyses. The work was funded by the Fisheries Research and Development Corporation (Project no. 2002/001), and logistic support was provided by both the South Australian Research and Development Institute and the University of Adelaide. BMG was supported by an ARC QEII Research Fellowship.
Bailey, K. M. (1997). Structural dynamics and ecology of flatfish populations. Journal of Sea Research 37, 269–280.
| Crossref | GoogleScholarGoogle Scholar |
Campana, S. E. (1999). Chemistry and composition of fish otoliths: pathways, mechanisms and applications. Marine Ecology Progress Series 188, 263–297.
Elsdon, T. S. , and Gillanders, B. M. (2003). Relationship between water and otolith elemental concentrations in juvenile black bream Acanthopagrus butcheri. Marine Ecology Progress Series 260, 262–272.
Gillanders, B. M. (2002). Temporal and spatial variability in elemental composition of otoliths: implications for determining stock identify and connectivity of populations. Canadian Journal of Fisheries and Aquatic Sciences 59, 669–679.
| Crossref | GoogleScholarGoogle Scholar |
Kraus, R. T. , and Secor, D. H. (2004). Incorporation of strontium into otoliths of an estuarine fish. Journal of Experimental Marine Biology and Ecology 302, 85–106.
| Crossref | GoogleScholarGoogle Scholar |
McGlennon, D. , Jones, G. K. , Baker, J. , Jackson, W. B. , and Kinloch, M. A. (2000). Ageing, catch-at-age and relative year class strength for snapper (Pagrus auratus) in northern Spencer Gulf, South Australia. Marine and Freshwater Research 51, 669–677.
| Crossref | GoogleScholarGoogle Scholar |
Ward, T. M. , and Staunton-Smith, J. (2002). Comparison of the spawning patterns and fisheries biology of the sardine, Sardinops sagax in temperate South Australia and sub-tropical southern Queensland. Fisheries Research 56, 37–49.
| Crossref | GoogleScholarGoogle Scholar |
![](../../media/share/OpenURL_Image.gif)
Yoshinaga, J. , Nakama, A. , Morita, M. , and Edmonds, J. S. (2000). Fish otolith reference material for quality assurance of chemical analyses. Marine Chemistry 69, 91–97.
| Crossref | GoogleScholarGoogle Scholar |
![](../../media/share/OpenURL_Image.gif)