Strong population structure deduced from genetics, otolith chemistry and parasite abundances explains vulnerability to localized fishery collapse in a large Sciaenid fish, Protonibea diacanthus

Authors

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

Document Type

Article

Publication Date

6-5-2017

Journal Title

Evolutionary Applications

ISSN

ISSN1752-4571eISSN1752-4571

Keywords

Croaker, Fisheries management, Otolith chemistry, Parasites, Population genetics, Stock discrimination

Disciplines

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

Abstract

As pressure on coastal marine resources is increasing globally, the need to quantitatively assess vulnerable fish stocks is crucial in order to avoid the ecological consequences of stock depletions. Species of Sciaenidae (croakers, drums) are important components of tropical and temperate fisheries and are especially vulnerable to exploitation. The black-spotted croaker, Protonibea diacanthus, is the only large sciaenid in coastal waters of northern Australia where it is targeted by commercial, recreational and indigenous fishers due to its food value and predictable aggregating behaviour. Localized declines in the abundance of this species have been observed, highlighting the urgent requirement by managers for information on fine- and broad-scale population connectivity. This study examined the population structure of P. diacanthus across north-western Australia using three complementary methods: genetic variation in microsatellite markers, otolith elemental composition and parasite assemblage composition. The genetic analyses demonstrated that there were at least five genetically distinct populations across the study region, with gene flow most likely restricted by inshore biogeographic barriers such as the Dampier Peninsula. The otolith chemistry and parasite analyses also revealed strong spatial variation among locations within broad-scale regions, suggesting fine-scale location fidelity within the lifetimes of individual fish. The complementarity of the three techniques elucidated patterns of connectivity over a range of spatial and temporal scales. We conclude that fisheries stock assessments and management are required at fine scales (100 s of km) to account for the restricted exchange among populations (stocks) and to prevent localized extirpations of this species. Realistic management arrangements may involve the successive closure and opening of fishing areas to reduce fishing pressure.

Recommended Citation

Taillebois L, Barton DP, Crook DA, et al. Strong population structure deduced from genetics, otolith chemistry and parasite abundances explains vulnerability to localized fishery collapse in a large Sciaenid fish, Protonibea diacanthus. Evol Appl. 2017; 10: 978–993. https://doi.org/10.1111/eva.12499