Variation in stable isotope (δ18O and δ13C) signatures in the sagittal otolith carbonate of king threadfin, Polydactylus macrochir across northern Australia reveals multifaceted stock structure

Authors

Stephen J. Newman, Department of Fisheries, Western AustraliaFollow
Quentin Allsop, NT Fisheries, Department of Resources, Darwin, Northen Territory, Australia
Aaaron C. Ballagh, James Cook University, Queensland, Australia
Rod N. Garrett, Queensland Department of Employment, Economic Development and Innovation, Northern Fisheries Centre, Queensland, Australia
Neil Gribble, Queensland Department of Employment, Economic Development and Innovation, Northern Fisheries Centre, Queensland, Australia
Jessica J. Meeuwig, The University of Western Australia
Gabby E. Mitsopoulos, Department of Fisheries, Western AustraliaFollow
Bradley R. Moore, James Cook University, Australia
Matthew B. Pember, Department of Fisheries, Westerrn Australia
Ben M. Rome, Department of Fisheries, Western Australia
Thor Saunders, NT Fisheries, Department of Resources, Darwin, Northen Territory, Australia
Craig L. Skepper, Department of Fisheries, Western AustraliaFollow
Jason M. Stapley, Queensland Department of Employment, Economic Development and Innovation, Northern Fisheries Centre, Queensland, Australia
Lynne van Herwerden, James Cook University, Queensland, Australia
David J. Welch, James Cook University, Queensland, Australia

Document Type

Article

Publication Date

9-28-2010

Journal Title

Journal of Experimental Marine Biology and Ecology

ISSN

Print: 0022-0981 Electronic: 1879-1697

Keywords

King threadfin, Polydactylus macrochir, Polynemidae, Otolith isotope chemistry, Stock structure

Disciplines

Aquaculture and Fisheries | Genetics | Marine Biology | Natural Resources and Conservation | Natural Resources Management and Policy | Population Biology | Spatial Science | Sustainability

Abstract

Otoliths of king threadfin, Polydactylus macrochir were collected from 2007 to 2009 at nine locations across northern Australia representing most of their distributional range and areas where fisheries are active. Measurement of the stable isotope ratios of δ18O and δ13C in the sagittal otolith carbonate from assemblages of P. macrochir revealed location-specific signatures and indicated that adult fish sampled from representative sites across their range were significantly different. The significant differences in the isotopic signatures of P. macrochir demonstrated that population subdivision is evident and there is unlikely to be substantial movement of fish among these distinct adult assemblages. The stable isotopic signatures for the fish from the different locations were persistent through time, and therefore it could be concluded that they comprise separate stocks for many of the purposes of fisheries management. The spatial separation of these populations indicates a complex stock structure across northern Australia with stocks of P. macrochir associated with large coastal beaches and embayments on a fine spatial scale. These results indicate that in order to achieve optimal fisheries management, the current spatial management arrangements need to be reviewed, particularly the potential for localised depletion of stocks on small spatial scales. This study has provided further evidence that measurement of the stable isotopes ratios in teleost sagittal otolith carbonate can be a valuable tool in the delineation of fishable stocks or fishery management units of adult fish and that widely distributed fish can nonetheless show strong localised population structure.

Recommended Citation

Stephen J. Newman, Quentin Allsop, Aaron C. Ballagh, Rod N. Garrett, Neil Gribble, Jessica J. Meeuwig, Gabby E.A. Mitsopoulos, Bradley R. Moore, Matthew B. Pember, Ben M. Rome, Thor Saunders, Craig L. Skepper, Jason M. Stapley, Lynne van Herwerden, David J. Welch, Variation in stable isotope (δ18O and δ13C) signatures in the sagittal otolith carbonate of king threadfin, Polydactylus macrochir across northern Australia reveals multifaceted stock structure, Journal of Experimental Marine Biology and Ecology, Volume 396, Issue 1, 2010, Pages 53-60, ISSN 0022-0981, https://doi.org/10.1016/j.jembe.2010.09.011.