Opportunities and impacts of range extending scalefish species: understanding population dynamics, ecosystem impacts and management needs
Species-level responses to ocean warming is a priority research area as they underpin the structure and function of marine ecosystems and the productivity of fisheries that operate within them.
There are a number of range extending species that have become increasingly abundant in Tasmanian waters, providing new fishing opportunities for recreational and, to a lesser extent, commercial fishers. Species in this group include Pink Snapper, King George Whiting and Yellowtail Kingfish. While King George Whiting are known to spawn off the north coast it is unclear as to whether the other species have or are likely to become established as self-sustaining populations in Tasmanian waters or simply persist as spill-over from populations that are centered off mainland Australia. If the former is the case, it will be especially important to consider population attributes such as growth, mortality and reproductive dynamics relevant to the Tasmanian populations when developing and refining management arrangements to maximise the opportunities these 'new' species bring.
In addition, the broader ecosystem impacts of such range extending species, including competition with resident species at similar trophic levels, are unknown but could have consequences for other recreationally and commercially important species. Understanding these relationships will have benefits for the assessment and management of the Tasmanian recreational fishery more generally.
Final report
This work set out to quantify the biology and diet of three key range-shifting species in Tasmania with both recreational and commercial fishery value. The project was heavily reliant on engagement from the recreational fishing community and multiple citizen science initiatives, as well as historical data.
The information collected was used in modelling to predict how suitable habitats for each species may shift under future climate change projections. The work also indicated the potential changes to the ecosystem (such as food web) if these species’ ranges were to move.
NCCP: Review of Carp control via commercial exploitation
Informing the structural reform of South Australia's Marine Scalefish Fishery
South Australia’s Marine Scalefish Fishery (MSF) is currently undergoing a strategic review with the principal aim of restructuring the fishery in order to ensure its long-term sustainability and economic viability. The heterogeneous mixture of participants, fishing devices, licence conditions and regulations associated with this fishery makes the tasks of administering and managing it extremely challenging. These complexities intertwined within a highly dynamic fleet that is capable of shifting fishing effort amongst species and regions often alters the emphasis of its overarching management. Industry and Government are working collaboratively to address the inherent complexities of the fishery through firstly developing a mechanism to rationalise the fleet, then reforming its overall structure, and ultimately refining its future management. In order to optimise this structural reform, it is necessary to disentangle and understand the fleet dynamics of this extremely complex fishery. This project aims to explore the implications of strategic management options (e.g. regionalisation, licensing, ITQ’s and ITE’s) on the future structure and viability of the MSF, from resource sustainability, economic and social perspectives.
Final report
This study was undertaken by the South Australia Research and Development Institute (SARDI) in collaboration with PIRSA Fisheries and Aquaculture, BDO EconSearch, the Marine Fishers Association (MFA), Fishwell Consulting and University of Canberra. This project guided the reform of South Australia’s commercial Marine Scalefish Fishery (MSF) by providing scientific advice and analyses to underpin its implementation. The MSF is a multi-sector, multi-gear and multi-species fishery, making any management reform a complex and difficult process. Both the sustainability of key stocks and commercial fishery’s economic performance have been deteriorating over a 20-year period; significantly influenced by fishery overcapitalisation. Simply put, there were too many fishers and not enough fish to support a vibrant and sustainable commercial fishery. This was addressed through the three ‘pillars’ of the reform: regionalisation, unitisation and rationalisation. These pillars were reflected in the reform with: 1) the creation of four new zones of management; 2) implementation of individual transferable quotas (ITQs) for appropriate ‘Tier 1’ stocks; and 3) rationalisation of the commercial MSF fleet by removing one third of licences through a voluntary licence surrender program (VLSP). These pillars were supported by research on the biological, economic and social carrying capacity of the fishery. The reform was implemented on 1 July 2021 resulting in a fishery that has regional management with appropriate output controls and a reduced fleet size.