TheFishSite.com - news, features, articles and disease information for the fish industry

Featured Articles

Status of Key Australian Fish Stocks 2012

Monday, March 11, 2013

The Status of key Australian fish stocks report, by the Australian Government, assesses the biological sustainability of the key wild caught fish stocks against a nationally agreed framework. In short, for the key fish stocks the report examines whether the abundance of fish (or biomass) and the level of harvest from the stock are sustainable.

This initial edition of the reports is the first step towards national fishery-wide reporting, that will consider other aspects of ecologically sustainable development, such as the effects of fishing on the marine environment, economic performance and governance. While these issues are not considered in the stock status classifications, the reports provide comments on the effects of fishing on the marine environment and environmental effects on the stocks.

Australia has one of the largest marine domains in the world, covering an area larger than the Australian mainland. We also have a long history of Indigenous, commercial and recreational fishing in our waters. Over the past decade, Australia’s fisheries production, both wild-capture and aquaculture, has generated, on average, $2.65 billion per year. In 2010–11, wild-capture fisheries contributed 59 per cent of the total value of Australia’s fisheries production ($1.3 billion) and produced more than 160 000 tonnes (t) of seafood, for local, domestic and export markets.

Australian seafood is very diverse, including scallops, prawns and squid, coastal fish such as whiting and flathead, reef fish such as Coral Trout and oceanic tuna and billfish. The fisheries that supply our seafood operate in estuaries and bays, across the continental shelf to oceanic waters and, in some cases, on to the high seas. The fisheries and the wild fisha stocks on which they are based are managed by eight jurisdictions (Figure 1). In general, the states and the Northern Territory manage fisheries that extend from the coast to a distance of 3 nautical miles, and the Commonwealth manages fisheries that extend from 3 nautical miles to the 200 nautical mile limit of the Australian Fishing Zone.

Contribution of each jurisdiction to gross value of wild-capture fisheries production, 2010–11

The productivity and sustainability of wild-capture fisheries depend on the wild fish stocks and marine ecosystems that support the fish. Fish species tend to form relatively discrete populations in different geographical areas that are referred to as biological stocks. Since separate biological stocks have limited interbreeding, fishing one may not directly affect others. The size and distribution of individual biological stocks vary greatly between species. For example, Southern Bluefin Tuna comprises a single biological stock that spans much of the world’s southern oceans. In comparison, hundreds to many thousands of separate biological stocks of Blacklip Abalone are thought to exist in Australia. A key aim of fisheries management is to ensure that biological stocks are maintained at sustainable levels. Although state/territory and Commonwealth jurisdictional boundaries may be appropriate from a governance perspective, many biological stocks straddle these boundaries, spanning the waters of more than one jurisdiction. The same fish species may be caught in several jurisdictions, in several fisheries and, in some cases, also outside Australian waters. The catch in the different jurisdictions may be from separate biological stocks of the species, which have little interaction, or from a single biological stock. Therefore, a national approach to assessing and reporting on the status of fish stocks is critical to understanding the state of wild-caught fish stocks and Australian fisheries management.

The stock status classifications presented in the Status of key Australian fish stocks reports are at the biological stock level wherever possible, even where a biological stock spans the waters of more than one Australian jurisdiction—that is, shared stocks. This recognises the biological boundaries of fish stocks rather than manmade boundaries of management units or jurisdictions. Where insufficient information was available to determine biological stock structure or where large numbers of small biological stocks made biological stock–based assessments impractical, stock status assessments were made at the level of management unit (i.e. individual fisheries, a group of fisheries or a region defined by management) or jurisdiction. Within the reports the term ‘stock status’ is applied generically to the status of biological stocks, management units and populations assessed at the jurisdictional level.

The Status of key Australian fish stocks reports 2012 are the first national reports on the status of Australian wild-caught fish stocks. The reports provide stock status assessments for 49 wild-caught species (or species complexes, in some cases) that contribute around 70 per cent of the annual catch and 80 per cent of the value of Australian wild-capture fisheries. The reports represent a significant step towards a national approach to reporting for Australian fisheries. These inaugural reports focus on the status of fish stocks based on five categories: sustainable stock, overfished stock, transitional–recovering stock, transitional–depleting stock and undefined stock. Future reports are envisaged to consider a larger number of species.

Traditionally, fishery status reporting has been undertaken separately within each Australian jurisdiction for commercial wild-capture fisheries. The jurisdictional reports use differing terminology and reference points to classify fish stocks. The Status of key Australian fish stocks reports present assessments of stock status using a nationally agreed framework, to improve consistency in reporting across jurisdictions. At present, separate jurisdictional reports, such as the Fishery status reports produced for Commonwealth fisheries by the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES), will continue to be produced to meet legislative and policy requirements specific to each jurisdiction. For Commonwealth fish stocks, the inaugural Status of key Australian fish stocks reports consider equivalent biological information to that presented in the Fishery status reports 2010 but present classifications based on the nationally agreed classification framework. In developing the Status of key Australian fish stocks reports, several jurisdictions have reviewed their status determination processes and are modifying their jurisdictional reports to follow the framework applied in the national reports, where possible. As future editions of the Status of key Australian fish stocks reports are produced, increased coverage (i.e. including more species and reporting on fishery-level issues) may lead to a reduced requirement for separate jurisdictional reports.

National Framework for Stock Status Reporting

The national reporting framework used in the Status of key Australian fish stocks reports was developed collaboratively by fisheries scientists from around Australia. This framework uses standardised terminology and reference points for stock status classifications. Wherever possible, the classifications are presented at the biological stock level, even where a biological stock spans the waters of more than one Australian jurisdiction (i.e. shared stocks). This level of reporting aims to recognise the biological boundaries of fish stocks rather than manmade boundaries of management units (i.e. fisheries) or jurisdictions (i.e. the borders of the waters of the Commonwealth, the states or the Northern Territory). The biological stock level of reporting recognises that all Australian fisheries for a particular species may not be of the same biological stock; for example, fishing for Tiger Prawns on the east coast of Queensland has no impact on the status of Tiger Prawns stocks in the Gulf of Carpentaria. Jurisdictional fishery status reports do not always present status at the biological stock level. In the Status of key Australian fish stocks reports, reporting was undertaken at the level of manmade management units or within jurisdictional boundaries only in cases where biological stock delineation is not known (i.e. it is not known exactly where one stock finishes and the next begins) or the numbers of stocks for a species are very high. The term ‘stock status’ is used throughout to refer generically to all three levels of stock status assessment, i.e. biological stocks, management units and populations assessed at the jurisdictional level.

The national framework for these reports considers both the abundance (number or biomass [weight]) of fish in a stock and the level of fishing pressure (rate of fishing) applied to a stock. The status classifications assess whether the current abundance of fish in a stock is adequate—that is, whether there is a large enough proportion of the original adult stock remaining that the production of juveniles is not significantly reduced. They also assess whether the amount of fish currently being removed through fishing is adequately controlled to ensure that stock abundance is not reduced to a point where production of juveniles is significantly reduced. The framework makes these assessments against the biomass reference point of ‘recruitment overfished’, which is the point at which the spawning stock biomass has been reduced by fishing so that average recruitment levels are significantly reduced. There are five classification categories (refer to Introduction for full description):

  • Sustainable stock—indicates that biomass (or biomass proxy) is at a level sufficient to ensure that, on average, future levels of recruitment are adequate (i.e. not recruitment overfished) and that fishing pressure is adequately controlled to avoid the stock becoming recruitment overfished.
  • Transitional–recovering stock—indicates that biomass is recruitment overfished, but management measures are in place to promote stock recovery, and recovery is occurring.
  • Transitional–depleting stock—indicates that biomass is not yet recruitment overfished, but fishing pressure is too high and moving the stock in the direction of becoming recruitment overfished.
  • Overfished stock—indicates that the stock is recruitment overfished and current management is not adequate to recover the stock, or that adequate management measures have been put in place but have not yet resulted in measurable improvements.
  • Undefined stock—indicates that not enough information exists to determine stock status.

Key Results

In total, 150 stock status assessments were undertaken across the 49 species chapters, with assessments undertaken at the biological stock level, wherever possible.

A stock status classification could be determined from 111 of the stocks assessed. The remaining 39 were classified as undefined stocks. The undefined stock classification does not necessarily mean the stock is at increased risk. It means that there is limited or conflicting information available to undertake the assessment.

Of the 111 stock status classifications that could be assigned, 98 stocks were assessed as being sustainable stocks, 8 transitional–recovering stocks, 3 transitional–depleting stocks, and 2 overfished stocks (Tables 1 and 2). The two stocks classified as overfished are the Southern Bluefin Tuna stock and the School Shark stock.

There were 81 stock status assessments carried out at the biological stock level. Of these, 53 biological stocks were considered sustainable stocks, 5 transitional–recovering stocks, 3 transitional–depleting stocks, 2 overfished stocks, and 18 undefined stocks (Tables 1 and 2).

Sixty-nine stock status assessments could not be carried out at the biological stock level. Of these, 45 stock status assessments are presented at the management unit level and 24 at the jurisdiction level.

Of the 45 stock status assessments carried out at the management unit level, 35 management units were considered to be sustainable stocks and 2 transitional–recovering stocks; none were classified as transitional–depleting stocks or overfished stocks, and 8 were undefined stocks (Tables 1 and 2).

Of the 24 jurisdiction-based stock status assessments, 10 assessments were considered sustainable stocks and 1 transitional–recovering stock; none were classified as transitional–depleting stocks or overfished stocks, and 13 were undefined stocks (Tables 1 and 2).

The total volume of catch reported in the Status of key Australian fish stocks reports from Australian managed fisheries is 121 230 t. This volume represents over 70 per cent of the total Australian wild catch reported in 2009–10 (i.e. 173 340 t). The 121 230 t total does not include international catches (i.e. catch taken outside Australian waters by countries other than Australia) of the tuna and billfish species that are reported in the Status of key Australian fish stocks reports. The Australian catch of these species is small in comparison to the international catch.

Of the Australian catch reported in the Status of key Australian fish stocks reports, 91 per cent is from sustainable stocks, less than 1 per cent is from transitional–recovering stocks, less than 1 per cent from transitional–depleting stocks, 3.5 per cent is from overfished stocks, and 4.5 per cent is from undefined stocks (Table 2).

In future editions of the Status of key Australian fish stocks reports, it is intended that most species currently assessed for stock status at the level of management unit or jurisdiction will be assessed at the biological stock level, where research has revealed the biological stock boundaries.

In addition to assessing the status of the species, the Status of key Australian fish stocks reports provide key statistics and main features of the fisheries that target each species, the effects of fishing on the marine environment and environmental effects on fish stocks.

Stock Status Classification Summary of the Stocks in the Status of Key Australian Fish Stocks Reports 2012, and the Proportion of the Catch of All Species Considered in the Reports

a The total does not include international catches (i.e. catch taken outside Australian waters by countries other than Australia) of the four tuna and billfish species.

Further Reading

You can view the full report by clicking here.

March 2013

Share This

Industry Showcase

Our Sponsors

Partners


Seasonal Picks

Fundamentals of Ornamental Fish Health - 5m Books

The Shrimp Book - 5m Books.com