Queensland and the Northern Territory legislations require sustainable harvest of fish resources and their optimal use. Reliable and robust information on the status of fished resources are central to achieving such outcomes. Each jurisdiction has its own management regime for the mackerel fisheries in their corresponding waters. The lack of information on stock structure, however, means that the appropriate scale of management is not known. As well, fishers have no guidelines to encourage investment and long-term involvement in a fishery that supplies lucrative overseas markets. These management- and fisher-unfriendly circumstances must be viewed in the context of dramatic declines in catches of grey mackerel along the Queensland east coast, combined with significant and increasing catches in other parts of the species' northern Australian range. Such a scenario highlights the urgent need for information on the stock structure of this species.

At its August 2003 meeting, the Northern Australian Fisheries Management Forum (NAFMF) signaled its intention to move from single jurisdiction-based fishery management towards a more integrated approach that reflected the management needs of species across their northern Australian range. In 2004, NAFMF progressed this undertaking for grey mackerel, with the development of an operational plan for sustainable harvest across northern Australia. In order to obtain the maximum benefit from this initiative, the underlying stock structure of grey mackerel must be established. Furthermore, the proposed project is consistent with the strategic directions of the Northern Territory Strategic Plan for Fisheries Research and Development, particularly those directives related to the sustainable harvesting of fish and other aquatic resources, and the optimum utilisation of fish and aquatic resources.