Australia State of the Environment Report 2001 (Theme Report)
Australian State of the Environment Committee, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06751 5
Environmental indicators reported in this section:
|CO 4.2||Aquaculture production|
|CO 4.3||Fish stocks|
|CO 4.4||Seafood quality|
|CO 7.8||Fishing effects on non-target species|
Fishing occurs over the whole of Australia's marine environment - in estuaries, coastal waterways, nearshore waters, deep oceans and sub-Antarctic waters. Some fisheries extend into international waters. It is one of the few industries operating on the basis of harvesting native species.
The commercial fishing industry is an important primary industry. Marine recreational fishing is a significant activity, and fishing is of great importance to many Aboriginal and Torres Strait Islander communities. Because the marine environment is very diverse in terms of the different physical features, species and ecosystems, fisheries management and conservation varies from region to region.
The Australian Fisheries Management Authority (AFMA) is the Commonwealth authority responsible for the management of Commonwealth fishery resources within the 200 nautical mile Australian Fishing Zone (AFZ) and, in some cases, by agreement with the States, to the low water mark.
Figure 20: Status of Australian fisheries, 1999.
Source: Bureau of Rural Sciences (2000)
Australia's Fishing Zone is the world's third largest, comprising some nine million square kilometres. Although Australia ranks only about fiftieth in world fish production in tonnage terms, many Australian fisheries target high-value species such as prawns, lobsters, abalone and tuna. In 1999-2000 the gross value of Australia's fisheries production, including aquaculture, increased by an estimated 13% to A$2.32 billion, despite a 7% decline in production to around 221 400 tonnes. Of this, the Commonwealth-managed component was about A$413 million (ABARE 2001), contributing about 20% of Australian fisheries production, the major fisheries being the Northern Prawn, Southern Bluefin Tuna, and the South East Trawl and Non-Trawl Fisheries.
Figure 21: Australian fisheries production from 1995-96 to 1999-2000.
Source: after ABARE (2001)
Major State-managed fisheries include the Western Rock Lobster, abalone, and Pearl Oyster fisheries.
Fishing activities affect not only the target species but also the ecosystems from which the fish are captured, and other species that are caught or otherwise affected. Protected species such as turtles, sharks and seabirds may be caught or killed incidentally by fishing activities. A wide range of benthic species may also be caught or affected in trawl nets and dredges. Bycatch species and discarded fish may also be removed from marine and coastal waters during commercial fishing activities.
The state of knowledge of the biology and the stock status of many fish species is incomplete. Around 3600 of Australia's estimated 4500 fish species have been described, but the status of most is unknown.
Fish are captured at the seafloor (demersal fishing with bottom trawls, dredges, traps) and from ocean waters (pelagic fishing with longlines and purse-seines). Aquaculture is conducted in coastal waterways, estuaries or in sheltered nearshore waters. The catch of fish can be related to the productivity of the populations, but is also influenced by technological factors.
Information on the conduct of fishing using lines and nets is given in a study undertaken for SoE reporting purposes (Commonwealth of Australia 2001b). The report found that the intensity of fishing varies greatly from place to place, and there was insufficient information to give a national overview of the spatial extent and intensity of net and line fishing.
The same report investigated trawl areas and intensities of fishing effort. The study identified that the intensity of trawling in the South East Trawl Fishery is increasing, while in the Northern Prawn Fishery the intensity and area have decreased substantially in the last decade. The area trawled in the East Coast Trawl Fishery off the coast of Queensland has increased steadily over the last two decades but has recently been restricted in the Great Barrier Reef World Heritage Area. Areas of high trawling intensity tend to be very small relative to the total area of the respective trawl fishery. The impact of trawling depends on the combination of trawl frequency and intensity, and the susceptibility of the habitats and species being trawled. Nonetheless, even infrequent trawls may still cause ecological damage in habitats that are slow to recover.
Information about gear or effort is useful for formulating management actions, such as capping fishing effort, targeting species better, or introducing mitigation measures.
The most important issue for fisheries in Australia is to ensure the ecological sustainability of fish stocks in the long term so that ecosystems that are fished remain diverse and healthy.
The environmental issues of most importance are:
- the management of fishing effort and activity so as to minimise impacts on habitats and ecosystems and maintain ecological sustainability;
- the sustainable management of target species;
- the reduction of impacts on species, other than target species, removed or injured during fishing activities;
- the impacts of marine pests on the environment (see Introduced marine species and marine pests)
- fishing activities' effects on benthic and pelagic ecosystems; and
- the loss of inshore nursery habitats and pollution from land-based activities.
Status of commercial wild capture stocks [CO Indicator 4.3]
The status of Commonwealth-managed commercial fisheries is assessed and summarised in the annual Bureau of Rural Sciences Fisheries status reports (Caton and McLoughlin 2000).
The level of uncertainty in scientific assessments of the status of fisheries remains relatively high, and the 1999 assessments showed a trend within Commonwealth-managed fisheries to fewer fisheries/species classified as 'underfished' and more classified as 'uncertain' (13 in 1998 and 15 in 1999). The increased number of 'uncertain' fisheries/species is a combination of new fisheries and, with increased information, increasing uncertainty in previously assessed fisheries. The status of most bycatch species is uncertain.
Four Commonwealth fisheries/species groups are regarded as overfished. They are Southern Bluefin Tuna, school shark, tiger prawn in the Northern Prawn Fishery and Eastern Gemfish stocks. The species are also caught in State-managed fisheries.
About three-quarters of Australia's fisheries are under State and the Northern Territory jurisdiction. Statistics on catches are compiled by the Australian Bureau of Agricultural and Resource Economics each year (e.g. ABARE 2001). Most of the fish stocks managed by Western Australia are still productive, but are nearing the limit of their ability to support further fishing (Fisheries Western Australia 2000a). Queensland fisheries are generally fully fished (Williams 1997) and New South Wales' commercial wild-catch fisheries are fully fished (Fletcher et al. 1999).
A summary of the condition of all of Australia's fish stocks is not yet possible, owing to differing reporting approaches in the various States and the Northern Territory and the Commonwealth.
One of the problems in attempting to assess the overall status of fisheries is that there is no national fisheries statistics database from which to assess trends. As the fishing industry depends on the sustainability of species for its continuing viability, the need for information on the status of commercial fisheries is vital.
There are fisheries developing in Australia's external territorial waters. The Macquarie Island Fishery was established in late 1996 after two seasons of exploratory fishing. A precautionary total allowable catch (TAC) limit for Patagonian Toothfish (see The complexity of fisheries management) has been set. There are strict operating conditions for this fishery to protect fish stocks and non-target species.
It is widely held that the sustainable development of Australia's fishing industry will involve making greater returns by increasing quality or value-adding to the wild caught product rather than by increasing the total tonnage of fish.
There are very few examples in which fisheries management can claim clear success in achieving regulatory goals. The Western Australian Western Rock Lobster Fishery and the Tasmanian abalone fishery have managed to rebuild stocks over several years.
The Western Australian Western Rock Lobster Fishery is an example of a well-managed fishery. Although catches in 1991-92 and 1992-93 were high, scientists highlighted that the breeding stock had been fished down to about 15% of the unfished stock. This was below the internationally safe level of about 25% of breeding stock. Tight management arrangements introduced in 1993-94 were aimed at rebuilding the breeding stock. This aim is being achieved. Catches since 1994-95 have averaged around 10 000 tonnes, with the 1998-99 catch a record 13 009 tonnes (Penn 1999). The West Australian Western Rock Lobster Fishery is the first fishery in the world to attain certification under the Marine Stewardship Council (London) as well managed and sustainable (see http://www.msc.org [accessed 5 September 2001]).
As part of this certification, to ensure that environmental impacts continue to be minimal, the fishery has been required to improve specific aspects of its environmental performance. These include: the development and implementation of an Environmental Management Strategy based on a comprehensive ecological risk assessment, the increased participation of environmental organisations in decision-making in the fishery, and the implementation of an improved monitoring program for bycatch of species (e.g. sea lions and turtles).
Figure 22: Western Rock Lobster annual catch.
Source: After SoE (1996) and Fisheries Western Australia Annual Reports
The Tasmanian abalone fishery is the largest wild harvest abalone fishery in the world. While other wild fisheries are currently grappling with the problems of overfishing, the Tasmanian fishery has been able to lift production following a period of stock rebuilding through the late 1980s and 1990s. Three stepwise increases in the total allowable catch (TAC) have occurred since 1997, the most recent in 2001.
An aggregation of abalone in a gutter on the north-west coast of Tasmania.
Source: Tasmanian Aquaculture and Fisheries Institute
Concerns held by members of the fishing industry and the Tasmanian Fisheries Department saw the introduction of a quota system in 1985, associated with a significant reduction in the catch. The quota was further reduced between 1985 and 1989 to 2100 tonnes, a reduction of 45% over four years. The TAC (for Blacklip and Greenlip Abalone combined) remained static from 1989 to 1996 before the first increase in 1997 when the TAC was set at 2520 tonnes. The TAC rose to 2800 tonnes for 2001.
A feature of the fishery over the last few years has been an increasing concentration of effort in the south and south-east and a corresponding reduction of effort in the west and north of the State. It is noteworthy that previous stock assessments have shown high catch rates of above-average size abalone on the west coast, but effort has gradually moved to more accessible areas.
To redress this trend, and spread effort more evenly around the State, a system of regional zones was introduced in 2000, with the catch to be taken from each zone determined by the TAC. Two Blacklip Abalone zones were supplemented by a third zone in 2001 with the TAC allocated as follows: eastern zone 1120 tonnes; western zone 1260 tonnes; northern zone 280 tonnes; greenlip zone 140 tonnes.
The Tasmanian TAC for the entire abalone fishery for 2001 is the sum of these regional TACs, i.e. 2800 tonnes. Figure 23 shows the annual landings of abalone in Tasmania.
Figure 23: Annual landings of abalone in Tasmania.
Source: DPIWE Tasmania (2000)
Another important facet of the fishery is marked geographical differences in growth rates of abalone around the State. For example, Blacklip Abalone generally grow faster in the south of the state than in the north. To address this issue, three different size limits now apply to both Blacklip and Greenlip Abalone.
The value of the fishery has fluctuated over the past eight years and shows little relationship to catch. Prices and catches have varied since the early 1990s with beach prices reaching historic highs over $50 per kilogram during 2000. These strong prices saw the value of the fishery reach $128 million in 2000.
Orange Roughy remains the most valuable single species in the South Eastern Trawl Fishery, with a value of A$12.7 million in 1998 (Caton and McLoughlin 2000). This species is a long-lived, low breeding fish (it produces low numbers of eggs compared to other fish) that is vulnerable to fishing pressure because of its aggregating behaviour. Since 1992 catches of Orange Roughy have continued to decline in the South East Trawl Fishery. The assessment that in 1997 a catch reduction in parts of the Fishery was warranted, was not accepted by the industry. A second wave of Orange Roughy exploitation occurred in the South Tasman Rise (which straddles the AFZ) following discovery of aggregations in September 1997.
Both Australia and New Zealand have fished the South Tasman Rise since 1997 with varying degrees of success in allocating catch levels and capping the fishing of Orange Roughy.
Figure 24: Orange Roughy annual catch.
Source: after SoE (1996) and Caton and McLoughlin (2000)
The Southern Bluefin Tuna is a highly migratory, long-lived species that was heavily overfished by a number of countries in the 1970s and 1980s. The international management of the fishery involves Australia, New Zealand and Japan, through the Commission for the Conservation of Southern Bluefin Tuna (CCSBT). Other countries also fish for Southern Bluefin Tuna outside the CCSBT management regime, though the Republic of Korea has announced it will accede to the Convention, South Africa is considering becoming a member, and efforts are in train to develop a mechanism that will enable Taiwan to participate in the Commission. Australia has actively engaged in international forums to bring the global catch of the species under effective management. The focus of this work has been to bring all major Southern Bluefin Tuna fishing countries into the CCSBT, so that all nations can comply with the Commission's objective of rebuilding the stock by 2020.
Australia has maintained catch limits agreed to in 1993 when the Commission established a total catch of 11 750 tonnes, with Australia getting 5265 tonnes, Japan 6065 tonnes, and New Zealand 420 tonnes. Southern Bluefin Tuna is considered overfished, with total global landings of about 19 000 tonnes, mostly landed in Japan or Australia (Caton and McLouglin in press.).
There is uncertainty about the degree to which spawning stock will rebuild under the current global catch regime, given the complexities of management of a species that is not entirely within Australia's control. The nature of the fishery in Australia has changed, with more juveniles being caught and farmed (see Aquaculture).
Eastern Gemfish is taken in the Commonwealth South East Trawl Fishery (SETF) off southern New South Wales. This slow-growing, long-lived species was fished excessively in the 1970s and 1980s and will take many years to recover.
A zero catch limit was set from 1993 to 1996. The total allowable catch (TAC) for 1997 was set at 1000 tonnes but the catch was only 393 tonnes. Scientific advice was that the TAC for 1998 should be zero, but a total of 500 tonnes was allocated to cover bycatch and reduce discarding. The catch, however, was only 214 tonnes. The 1999 allocated catch for bycatch was 250 tonnes (actual catch 158 tonnes) and in 2000 the allocated catch for bycatch was reduced to 200 tonnes.
Eastern Gemfish remains vulnerable to targeted fishing as it aggregates for its spawning run.
Figure 25: Annual Eastern Gemfish catch.
Source: after SoE (1996) and Caton and McLoughlin (2000)