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Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.

Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.

Our Sea, Our Future
Major findings of the State of the Marine Environment Report for Australia

Compiled by Leon P. Zann
Great Barrier Reef Marine Park Authority, Townsville Queensland

Department of the Environment, Sport and Territories, Canberra (1995)
ISBN 0 642 17391 5

3. Major use of the marine environment and their impacts - continued

Fisheries

In Australia, fisheries are important for local consumption, export and recreation. Although Australians are primarily consumers of red meats, fish provides a relatively significant - and healthy - part of the diet. The average consumption of seafood in Australia is around 12 kilograms per person per year.(30)

Fishing is a major extractive use of the marine environment. Although fish are a renewable resource, fisheries production of a growing number of species has been declining since the late 1980s.(31)

Commercial fisheries and aquaculture

The Australian Fishing Zone has an area of nearly nine million square kilometres and is the third largest in the world. Despite this, Australia's fish catches are relatively low at about 200,000 tonnes each year, and only rank around 50th in the world. This is the result of the generally low productivity of our waters because of naturally limited run-off of nutrients from land, a relatively small area of continental shelf, and the absence of major upwellings of nutrient-rich deep waters. However, Australia has a number of high value export fisheries such as abalone, rock lobsters and prawns, and a large cultured pearl industry. Annual exports of marine products were valued at $1.1 billion in 1992-93.(30)

status of commercial fisheries

Australia's commercial fishing fleet consists of almost 10,000 vessels. Some 200 different species of fish, 60 species of crustaceans and 30 species of molluscs are fished.(30),(87)

Figure 65

Figure 65: The status of Commonwealth (or jointly-managed) commercial fisheries resources in Australia.

Australia has experienced declines in some commercial fisheries, particularly southern bluefin tuna, southern sharks and gemfish. There are also now serious concerns that the high catches of the long-lived, deep-sea orange roughy cannot be sustained.(30)

Of the 100 fisheries described in 'Australian fisheries resources' (87), nine are considered to be overfished, 23 are fully or heavily fished, nine are underfished, and 59 are of unknown status.

Reasons for declines in some fisheries include overfishing, use of non-selective fishing gear, loss of habitat, pollution and Australia's marine jurisdictional complexity which hinders management of a fish stock or population. While it is considered that many of Australia's fisheries have not been managed in a conservative manner in the past(31), fisheries managers are now focusing more on fisheries ecosystem management(84).

aquaculture

Aquaculture is an important and logical development from the capture fisheries, just as agriculture was a monumental step from hunting and gathering. Although Australia has long had oyster and pearl farms, we have generally lagged in other areas of aquaculture. However, aquaculture began to grow rapidly in the mid 1980s, and has increased in value from around $50 million in 1985, to $260 million in 1991-92. Sixty aquatic species, from seaweeds to crocodiles, are now farmed in Australia.(35)

Positive environmental consequences of aquaculture include the restocking of over exploited species, reduced fishing pressure on some wild stocks, and improved scientific understanding and management of wild stocks.(35)

Possible negative environmental results of aquaculture include:

The National Strategy on Aquaculture in Australia, released in 1994, aims to make improvements in land and water use planning, the use of chemicals, the management of species introductions, disease and pest controls, and research and training.(35)

Figure 69

Figure 69

Recreational fisheries: an important pastime for Australians

'Wetting a line' is an important part of our Australian way of life. Each year one in three of us go fishing for recreation. However, the fishing authorities have only recently recognised the recreational fishing sector's significance - in terms of its large share of the coastal catch as well as its social importance - and the industry remains largely unmanaged.(33)

Details on recreational fisheries remain sketchy. A 1984 survey estimated that over 4.5 million Australians went fishing at least once a year, and over 800,000 of these went fishing at least 20 times a year. Spending on fishing and related activities was estimated at $2.2 billion each year and later surveys suggest this figure is even higher. Some 100,000 people are directly employed in servicing Australia's huge recreational fishery.(33)

Recreational and sports fishing is a significant attraction for international tourists. It is estimated that in 1993 over 120,000 international tourists spent $210 million on fishing while in Australia.(33)

Australia's recreational fisheries are little managed although size limits (often imposed without adequate knowledge of the life history of the species) have existed for many years. Because of increasing pressure on stocks, bag limits have been imposed in recent years.(31),(33)

In 1991 the Standing Committee on Fisheries which comprised all Commonwealth and State heads of fisheries departments found that a national policy on recreational fisheries was needed and a working group was formed to develop this. Recommendations in the draft national policy include the management of recreational fisheries as part of the total fisheries resources, the accommodation of conservation and non-exploitative uses, and the development of a strong conservation ethic amongst fishers.(33)

The major concerns of the Australian Recreational and Sports Fishing Confederation, which represents some 220,000 fishing club members around the nation, are the management of recreational fisheries, the decline in the marine environment, conflicts with the commercial sector, and diminishing stocks.(53)

the catch-sharing issue

Australian recreational and commercial fishing sectors are increasingly competing for the same, often dwindling stocks. General concerns of recreational fishers centre on commercial netting which they think is responsible for declining fish stocks, the effects of trawling, the need to protect fish habitats, growing fishing pressure from both sectors and perceptions of unequal regulations which favour the commercial sector.(33)

Conversely, concerns of the commercial sector centre on their own strict regulation as opposed to limited regulation of the recreational sector, the individually small but cumulatively large effects of the recreational sector, and widespread illegal sale or 'black marketing' of fish by some recreational fishers. Efforts are now being made by fisheries managers to address these conflicts and some successes have been achieved, but it is unlikely that they will ever be completely resolved.(33)

Effects of fishing on the marine environment

Fishing has direct and indirect effects on marine ecosystems. The target species, some of which are large, high level predators in the ecosystem, are taken in what is akin to hunting in the terrestrial environment. In some fisheries, particularly those using trawl and gill nets, large numbers of other species, termed the 'by-catch', are also taken. Often the by-catch is then discarded. The proportion of the by-catch to the target species in some fisheries, for example the northern prawn fishery, can be as high as 8 to 1.(32)

Fishing may also cause indirect and very poorly understood effects on marine ecosystems such as alterations to population structures and food chains(32). Fundamental changes in food chains referred to as 'ecosystem flips', have occurred in large marine areas overseas(92). In Australia it has been suggested that outbreaks of the coral-eating crown-of-thorns starfish on the Great Barrier Reef and of Drupella snails in Western Australia have been caused by overfishing of their natural predators, although unambiguous scientific evidence for this is lacking in both cases(49),(50).

effects of trawling

The effects of trawling on the marine environment are of major concern in fisheries and environmental management around Australia. Very little is known of the environmental impacts of trawling. Possible effects include the reduction of fished and non-fished species, removal of organisms attached to the sea floor, and changes in food webs, including increased populations of scavengers such as seabirds, fish and crabs. Management strategies include better use of the by-catch, development of more selective fishing gear to reduce the by-catch, and spatial and seasonal closures to trawling to maintain biodiversity. However, compared with some other fishing nations, Australia has lagged in developing selective fishing gear.(32)

The effects of trawling are one of the major issues in the Great Barrier Reef Marine Park. Zoning prohibits trawling on about 20% of the sea floor and a major research program is underway to assess its impacts on bottom communities.(69)

shoreline fishing and harvesting

The increasing pressure on our shores from recreational activities such as fishing and collecting is an important concern around Australia, particularly near coastal cities, towns and tourist centres. Very little is known about the impacts of these pressures. Direct effects include reductions in target species such as molluscs, sea urchins, sea squirts and fish. Indirect effects include the loss of habitats, alteration of populations and disturbance of food chains. Because of growing concerns about over-harvesting in intertidal areas, New South Wales has introduced controls on harvesting techniques and bag limits, and established networks of Intertidal Protected Areas.(34)

Concerns of fisheries managers about the marine environment

Maintaining the habitat and good water quality are essential for fisheries. The overall goal for fisheries management in the National Strategy for Ecologically Sustainable Development (ESD) is for fisheries management agencies in Australia to adopt a fisheries ecosystem management framework which will provide a holistic and sustainable approach to the management of aquatic resources. Commonwealth and State/Territory fisheries agencies are now exploring how fisheries management can apply the concept of large marine ecosystems management and ESD.(30),(61),(84)

The major environmental concerns identified by Commonwealth and State fisheries managers in 1991 included impacts of point-source wastes, especially from industrial wastes; accumulation and effects of mercury, cadmium and other bio-accumulative substances, particularly in estuaries and coastal waters; effects of exotic species introduced via ships' ballast waters, particularly toxic phytoplankton and the Northern Pacific seastar; loss of fish habitats caused by coastal engineering works such as ports, canal estates, marinas, and dredging; die-back of southern seagrass beds; and adverse effects on shellfish by tributyl tin used in antifouling paints.(30)

While elevated nutrients have had a generally harmful effect on Australia's marine environment, they have had a beneficial effect in some places by enhancing plankton production and thereby increasing the growth of aquacultured oysters.(30) (The negative side is that this water may also be polluted by faecal bacteria and be a danger to oyster consumers(47).) While there are a few anecdotal reports of increased fish production in eutrophic estuaries, the overall effects of lost fish habitat because of eutrophication must far outweigh any local gains(42).