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 The reliance of current assessments on what is likely to be out-of-date information leads to increased uncertainty, which propagates into management decisions.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.

Commercial in confidence. To know more about this project please contact FRDC.

The Australian Southern Bluefin Tuna Association (ASBTIA) operates in shelf and offshore waters of the Great Australian Bight (GAB). In recognition of the exposed nature of the offshore GAB environment, ASBTIA have requested information to better understand the climatology of the physical meteorological and oceanographic conditions which contribute to the ‘sea-state’ and ocean conditions at a deep water petroleum permit location in the Great Australian Bight.

This project will provide the oceanographic services required to identify, access and analyse long-time series of relevant met/ocean parameters and statistically describe their climatology in order to better understand the ‘sea state’ characteristics of the GAB and how they compare with sites located within other international oil production regions.