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 The reliance of current assessments on what is likely to be out-of-date information leads to increased uncertainty, which propagates into management decisions.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

Despite the indicators of improvements in fish stock status for SESSF species, the fishery as a whole is failing to catch the TACs of many quota species. Moreover, catch rates for many quota species are continuing to decline despite the historically low levels of fishing effort. The fishery is not in an economic position where it can afford to operate below potential - this under catch equates to a considerable lost opportunity in both the financial value and the volume of fish available for the consumer. Net economic returns for the CTS have recently fallen to $1.4 million in 2013–14, the lowest level since the buyback. NER in the GHaT has been negative since 2008–09. Recent economc analyses (Pascoe pers comm) have revealed that if all vessels could catch the full recommended quota, revenues of the CTS would more than double, while the GHaT revenues would increase by around 24%. For the CTS, average vessel profits are likely to increase by between $200k and $500k, with an average increase of around $380k.

So, what is the cause of the current situation in the SESSF?

There are a variety of different reasons given for the SESSF's TAC undercatch, depending on who you talk to. Anecdotally, it has variously been attributed to reduction in fleet fishing capacity, effort reduction, legislative barriers, spatial closures, changed behaviour of operators, market factors, quota ownership and trading, cost of production, changes in catch per unit of effort, climate change and its impact on oceanographic conditions and potential range shifts of species. It is also quite likely that it is a combination of a number of the above factors.

What can be done?

With such a wide range of potential reasons, it is difficult to determine what further work is required to potentially address these issues in the SESSF. This project centres on development of background papers on each of the issues that will be presented at a workshop designed as the first step in clarifying stakeholder views on the underlying reasons and how they might be resolved in the future.