Revisiting biological parameters and information used in the assessment of Commonwealth fisheries: a reality check and work plan for future proofing
Much effort has been placed over the last couple of decades on the development of harvest strategies, stock assessments, risk assessments and the strategic use of ecosystem models to facilitate meeting the needs of the Commonwealth’s Harvest Strategy Policy. A focus on modelling to improve fisheries management has required effort towards method development. However, little effort has been made towards revisiting and updating the biological parameters that fundamentally underpin such modelling (e.g. growth rates, age and size at maturity, natural mortality rates, dietary information, mixing rates and stock structure) and the tools or methods used to derive them. As a result, most models now rely on parameters and community dietary data derived from information collected during the 1970s-1990s, (e.g. available maturity ogives for blue-eye trevalla are over 20 years old), or information that is borrowed from other regions or species. Whether such old or borrowed values are now representative for commercial Australian fish species is unknown but many factors point to major changes occurring in our marine environment. Australian waters in the south east and south west are climate hotspots and, overall, Australian waters have warmed faster than the global average. Key components of the productivity of marine fish (growth, maturity, and recruitment) are expected to be undergoing directional changes under a changing climate and it is entirely possible that there have been changes in fundamental productivity parameters for some Australian stocks. The reliance of current assessments on what is likely to be out-of-date information leads to increased uncertainty, which propagates into management decisions. Without an understanding of any changes in biological parameters and how any change might impact assessment frameworks, determining whether current management measures are ensuring sustainability becomes highly uncertain.
Final report
Southern Ocean IPA - Science to support Australia’s Southern Ocean Fisheries 2018-2020
Seafood CRC: Spatial management of southern rock lobster fisheries to improve yield, value and sustainability
Adapt or Fail: Risk management and business resilience in Queensland commercial fisheries
Vulnerability of the endangered Maugean Skate population to degraded environmental conditions in Macquarie Harbour
Tactical Research Fund: forecasting spatial distribution of SBT habitat in the GAB
The use of BRUVs as a tool for assessing marine fisheries and ecosystems: A review of the hurdles and potential
National reviews of Fisheries R&D needs (FRDC95/055) have identified the need for non-extractive, fishery-independent sampling and stock assessment techniques which are cost-effective, repeatable and robust across and range of habitats and depths. These methods are becoming increasingly important as Australian fisheries face the challenge of addressing ecosystem based fisheries management and climate change. A national workshop on the use of video for sensing the size and abundance of target and non-target fauna in Australian fisheries (FRDC2000/187) highlighted the potential for Baited Remote Underwater Video systems (BRUVs). After a decade, there has been wide adoption of this technique. However, differences in protocols for deployment, analysis and interpretation make spatial and temporal
comparisons of data difficult.
There is the need to develop a robust set of nationally agreed upon protocols to ensure that users are appropriately informed and trained through a comprehensive extension and capacity building program that also identifies key unresolved technical issues.
With the increased testing and use of BRUVs a number of independent developments have occurred. Future technological advances and more detailed statistical and modelling approaches will result in the BRUVs data being more useful for ecosystem assessment and management. Maximising the potential that these advances will provide to Australian fisheries will be achieved by a co-ordinated and
collaborative research strategy. We propose to host a two day workshop to critically evaluate the use of BRUVs as a data collection tool
for scalefishes and sharks. The workshop will identify the strengths, limitations and identify potential solutions.