Stock structure of Lethrinus laticaudis (Lethrinidae) across northern Australia determined using genetics, otolith microchemistry and parasite assemblage composition

Authors

Diane P. Barton, Charles Darwin University, Northern Territory
Laura Taillebois, Charles Darwin University, Northern Territory
Jonathan Taylor, Department of Primary Industry and Resources, Northern Territory
David Crook, Charles Darwin University, Australia
Thor Saunders, Department of Primary Industry and Resources, Northern Territory
Mark Hearnden, Department of Primary Industry and Resources, Northern Territory
Alan Greig, The University of Melbourne, Victoria
David J. Welch, C2O Fisheries, Cairns, Queensland
Stephen J. Newman, Department of Primary Industries and Regional Development, Western AustraliaFollow
Michael J. Travers, Department of Primary Industries and Regional Development, Western AustraliaFollow
Richard J. Saunders, Centre for Sustainable Tropical Fisheries and Aquaculture, Townsville, Queensland,
Chris Errity, Department of Primary Industry and Resources, Northern Territory
Safia Maher, The University of Queensland, Australia
Christine Dudgeon, The University of Queensland, Australia
Jennifer Ovenden, The University of Queensland, Australia

Document Type

Article

Publication Date

1-12-2018

Journal Title

Marine & Freshwater Research

ISSN

Print: 1323-1650 Electronic: 1448-6059

Keywords

Grass emperor, Lethrinus laticaudis (Lethrinidae), Northern Australia, Nearshore reef system, Population genetics, Fishery, Otolith

Disciplines

Aquaculture and Fisheries | Marine Biology | Natural Resources and Conservation | Natural Resources Management and Policy

Abstract

The grass emperor Lethrinus laticaudis is a conspicuous element of the commercial and recreational catch from nearshore reef systems across northern Australia. The nearshore reef systems across northern Australia are exposed to increasing levels of fishing pressure from commercial and recreational fishers. To inform ongoing management of this species, the present study examined the stock structure of L. laticaudis across northern Australia using a combination of complementary techniques. In all, 342 L. laticaudis samples were collected from 13 locations in the coastal waters of northern Australia ranging from the Pilbara region of Western Australia to Moreton Bay in south-east Queensland. Population genetic analyses using microsatellite markers demonstrated that there were at least four genetically distinct populations across northern Australia with gene flow between management jurisdictions (with significantly more separation between Western Australian and Northern Territory locations than between Northern Territory and Queensland locations). An isolation by distance effect was evident (genetic differences increasing linearly with distance). Otolith microchemistry and parasitology analyses indicated some spatial structuring of populations within broader regions. These findings of restricted connectivity at small spatial scales suggest that L. laticaudis is vulnerable to localised depletion in areas where fishing effort is concentrated. This conclusion is consistent with recent observations of fishery declines in heavily fished locations.

Recommended Citation

Barton Diane P., Taillebois Laura, Taylor Jonathan, Crook David A., Saunders Thor, Hearnden Mark, Greig Alan, Welch David J., Newman Stephen J., Travers Michael J., Saunders Richard J., Errity Chris, Maher Safia, Dudgeon Christine, Ovenden Jennifer (2018) Stock structure of Lethrinus laticaudis (Lethrinidae) across northern Australia determined using genetics, otolith microchemistry and parasite assemblage composition. Marine and Freshwater Research 69, 487-501.