Indicator: CO-16 Status of Australian fisheries

Data

The Bureau of Rural Sciences (BRS) has developed a methodology for assessing the status of commercial fish stocks according to whether they are, or are not, overfished. The status of some species remains uncertain and, until 2004, some had not been classified.

The following table provides an overview of the trends over the past years.

Trends in AFMA managed fish stocks
Stock status 1992 1993 1994 1996 1997 1998 1999 2000-2001 2002-2003 2004
Not overfished 17 29 28 28 20 18 17 19 20 17
Overfished 5 5 3 3 4 6 7 11 16 17
Uncertain 9 9 13 17 31 35 38 34 34 40
Unclassified 43 31 30 26 19 15 12 10 4 0

Classification categories used in Fishery Status Reports 2004 differ from those of previous reports. Species previously classified underfished or fully fished are combined in the table as not overfished. Overfishing counts for previous years are not available.

Source: A. Caton, K. McLoughlin 2005, Status of fish stocks managed by the Australian Government, viewed 8 Jun 2006, http://affashop.gov.au/product.asp?prodid=12985.

Overfished stocks for AFMA managed fisheries
Fish stock 2002 2003
Brown tiger prawn overfished fully fished
Black teatfish* (Coral Sea) overfished overfished
Blue warehou overfished overfished
Eastern Gemfish overfished overfished
Orange roughy (South East) overfished overfished
Redfish overfished overfished
Silver trevally overfished overfished
School shark overfished overfished
Southern scallop overfished overfished

*Also called Beche-de-mer. There are no verifiable data on Coral Sea stocks. This classification was made on the assumption that as Torres Strait stocks are overfished, the Coral Sea stocks are also overfished.

Source: AFMA 2004, Annual Report, viewed 8 Jun 2006, http://www.afma.gov.au/pubs/reports/ann_rep_0304/2003_04_part_3.pdf.

What the data mean

“Not overfished” means that fishing pressure on a fish stock has not yet exceeded the target reference points that have been determined for that species to be “fully fished”. Increasing fishing pressure may ultimately cause the stock to become overfished. “Overfished” means there are too few fish of a particular stock left to sustain continued fishing, while “overfished” means a stock is experiencing too much fishing to remain sustainable. “Uncertain” means a fish stock might or might not be not overfished but there is inadequate information to determine its status.

Scientists and managers adopt different criteria from fishery to fishery to classify the status of a fishery or stock and to define ‘optimum’ use of it. For example, in one fishery the catch might be regulated to maintain an agreed stock target. In another, the amount of fishing might be maintained close to an agreed target level. The status of a stock depends upon its current size (biomass) and the rate of removals from it (known as the exploitation rate or ‘fishing mortality’).

There has been a steady increase in the number of species overfished since 1997 but most of these species appear to have come from those that were previously unclassified, rather than from those classed as not overfished. The number that have been classified, although the status of many remains uncertain, has steadily increased. The number classed as “not overfished” increased in the early 1990s but had, in 2004, returned to its 1992 figure.

Data Limitations

The methodology used to determine what level of fishing unsustainable for different fish stocks does not take account of other environmental pressures, other than fishing, that may impact on fish stocks.

Additionally, the available data are restricted to Commonwealth fisheries which account for less than 30% of Australian fisheries production (in terms of value and weight) (see Indicator: Australian fisheries production: national tonnage and value of retained catch ). State fisheries do not have comparable methodologies for assessing the sustainability of their fisheries. While there is no reason to suspect the State fisheries are in any better condition than the Commonwealth fisheries, it needs to be remembered that the current data refer to less than 30% of the national fishery.

Issues for which this is an indicator and why

Coasts and Oceans — Condition of the ocean and coastal waters - Condition of fisheries 

Status of commercial fisheries does not give a comprehensive picture of the broader condition of marine species and ecosystems, but commercial fish species are important components of marine ecosystems and serious declines are likely to be indicative of broader ecological change. Status of commercial fisheries is assessable on the basis of catch changes, whereas the condition of non-commercial fish populations is much more difficult of assess.

Coasts and Oceans — Direct pressure of human activities on coasts and oceans - Pressure of fishing 

Commercial fishing is a direct human pressure on the coastal and marine environment. Changes in the status of commercial fisheries is indicative of changes in this pressure and of the effectiveness of responses to this pressure.

Other indicators for this issue:

Biodiversity — Species, habitats and ecological communities - Conservation status of species and ecological communities 

As well as being indicative of the condition of the ocean (and the contribution of biodiversity to that condition, and the capacity of the ocean to contribute to human life), status of fisheries may be indicative of the status of species and ecological communities more generally.

Other indicators for this issue:

Biodiversity — Species, habitats and ecological communities - Condition of marine biodiversity: Condition of fisheries 

Condition of commercial fisheries may be indicative of the condition of marine biodiversity more generally.

Biodiversity — Pressures on biodiversity - Pressures on marine biodiversity: pressures of fishing 

Fishing places pressure on marine biodiversity. Status of fisheries is indicative of the status of species and ecological communities more generally, and therefore provides insight into this pressure.

Other indicators for this issue:

Biodiversity — Utilisation and value of biodiversity - Harvesting and trade in wildlife 

Harvesting of wild fish is the principal commercial harvesting of wild animals in Australia.

Other indicators for this issue:

Australian Antarctic Territory — Environment - Human Pressures on the environment 

Fishing places pressure on marine biodiversity, including Antarctic species. Status of fisheries is indicative of the status of species and ecological communities more generally, and therefore provides insight into this pressure.

Other indicators for this issue:

Further Information