Long-term archaeological and historical archives for mulloway, Argyrosomus japonicus, populations in eastern South Australia

Native fish populations have been strongly impacted by fishing, habitat alteration and the introduction of invasive species. Understanding the dynamics of native fish populations prior to commercial fishing can be problematic, but provides critical baseline data for fish conservation, rehabilitation and management. We combined fish size, age and growth data, as well as month of catch data, from archaeological fish otoliths (1670–1308 cal BP to 409–1 cal BP), historical anecdotes (CE 1871–1999), and contemporary data sources (CE 1984–2014) to examine changes to mulloway, Argyrosomus japonicus, populations in the waters of eastern South Australia. We found that the data from the three different sources – archaeological, historical and contemporary – corroborate each other in many aspects. The time of catch for all three datasets was seasonal, with increases evident during the summer months. No significant changes in fish length over time were evident over the time span of the three data sources. Given the impact that fishing in the region is regarded to have had, this may imply that while the maximum recorded sizes of the species have remained stable, the abundance of these large specimens may have declined.This research was conducted with the support of the Australian Institute of Aboriginal and Torres Strait Islander Studies (G2011/7636 awarded to BMG and MD). The authors wish to thank AINSE Ltd. for providing financial assistance (ALNGRA11014 awarded to BMG and MD) to enable radiocarbon dating of five otolith samples to be conducted, and Greg Ferguson at SARDI who assisted with the ageing and growth determination for the archaeological mulloway. BMG acknowledges funding from the Australian Research Council through an ARC Future Fellowship (FT100100767) and an ARC Discovery project (DP110100716). SU is the recipient of an Australian Research Council Future Fellowship (FT120100656). Work on this paper was undertaken while SU was visiting as an Honorary Fellow in the School of Social Sciences, The University of Western Australia