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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Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time.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

4. General issues and pressures affecting Australia's marine environment - continued

Introduced species

Introduced or exotic species of plants and animals have had a catastrophic effect on Australia's unique terrestrial environment. While impacts of exotic organisms on the marine environment appear to have been relatively minor in the past, there is now great concern about the threats posed by the introductions of exotic marine species via ships' ballast waters.(48)

Blooms of introduced toxic marine algae are a serious marine environmental and fisheries problem in Tasmania and Victoria, and may threaten other States. Outbreaks of the exotic Northern Pacific seastar are spreading along eastern Tasmania, threatening marine life, aquaculture farms and scallop and abalone fisheries. There is also the serious threat of the introduction of marine diseases to our growing aquaculture industry, and of diseases such as cholera to humans.(48)

At least 55 species of fish and invertebrates and a number of seaweeds have been introduced into Australia either intentionally, for aquaculture, or accidentally, in ships' fouling and ballast waters. Six species are regarded as pests. Principal organisms of concern are the toxic alga Gymnodinium catenatum, which causes red tides, the seaweed Undaria pinnatifida, which smothers native kelps, the Northern Pacific seastar Asterias amurensis, and fish pathogens such as Myxosoma cerebralis.(48)

Introduced seastar a serious threat to Tasmania

Introduced seastar a serious threat to Tasmania

Australia, geographically isolated and traditionally free of agricultural diseases, is taking a leading international role in the management of exotic marine species. Management primarily focuses on the prevention of introductions. This includes the ocean exchange of ships' ballast waters on route, and by inspection and quarantine of imported organisms. Currently, ocean exchange is limited in some vessels by safety (stability) considerations and quarantine inspection is limited by delays in identification of organisms. Research is currently being conducted on both issues(84).

Past introductions of non-indigenous species onto islands, particularly those in the sub-antarctic, have had severe impacts on the islands' native fauna and flora.(48) These require special protection as their ecosystems are highly vulnerable to disturbance.(84)

Population outbreaks

Population explosions of certain native species have also been responsible for serious problems in the marine environment.

Crown-of-thorns starfish

Over the past 30 years outbreaks of the coral-eating crown-of-thorns starfish have caused considerable damage to Indo-Pacific reefs, including parts of the Great Barrier Reef and Australia's Tasman Sea reefs.(49)

Two episodes of outbreaks have affected parts of the Great Barrier Reef since 1960, and there are fears that numbers are building up towards a third. During the 1979 to 1990 episode around 17% of the 2,900 coral reefs were affected to some extent. Most of these were concentrated in the central one-third of the Reef.(49),(69)

Monitoring studies indicate that the faster growing corals take 10-15 years to recover from an outbreak. The cause of outbreaks, particularly whether they are natural or the result of human activities, is still not known. One hypothesis is that elevated nutrients from terrestrial run-off increase the survival of larvae. Another is that overfishing or over collection of natural predators increase survival of juveniles and adults. Many scientists now believe that there is no single, simple cause.(49)

The starfish outbreaks are regarded as one of the most serious management issues in the Great Barrier Reef Marine Park. Rather than attempt widespread, expensive and ineffectual eradication by diver programs, the Great Barrier Reef Marine Park Authority has channelled funds into

long-term multi-disciplinary research programs to find the cause(s) of the outbreaks. Controls are undertaken on reefs only of special importance to tourism or scientific research.(49),(69)

Drupella snails

In an alarming parallel with the crown-of-thorns outbreaks on the Great Barrier Reef, millions of small coral-eating Drupella snails have devastated approximately 100 kilometres of Ningaloo fringing reef in Western Australia. Similar concerns to the crown-of-thorns starfish have been raised on the causes of the outbreaks, possible human causes and on the feasibility of controls. Outbreaks have also occurred in Southern Japan and the Philippines. Some localised damage has occurred in the Cairns Section of the Great Barrier Reef Marine Park.(50),(70)

Figure 103

Figure 103: Areas affected by crown-of-thorns starfish and Drupella snails in Australia

Coral reefs are in a constant state of change and the snail outbreaks, like those of the crown-of-thorns, may be natural phenomena. Alternatively, it has been suggested that human influences such as overfishing of natural fish predators, such as sweetlips and wrasses, may be responsible. As with the crown-of-thorns starfish, further research on the biology and ecology of Drupella is necessary.(50),(70)

What do we know about Australia's marine environment? A review of marine scientific knowledge and its contribution to environmental management

The State of the marine Environment Report is a testimony to the state of marine environmental knowledge in this country(63). A major finding of this report is that there are serious gaps in scientific knowledge and understanding of the marine environment in Australia, both geographically and by issue. In particular there is a serious lack of long-term data on water quality(42-47), environmental health(6-14) and human uses(28-39) which could be used for quantitative 'state of the environment; reporting(94).

One explanation for this is the vast length of coastline and area of our sea, the large proportion of which is uninhabited or sparely inhabited(1), and our relatively small scientific population. Australia's marine science has grown very rapidly over the past 20 years, and we have achieved pre-eminence in areas of tropical ecology, especially coral reefs and their management. Australia is now amongst the world's top ten nations in marine research effort and output(63).

There is widespread agreement amongst scientists and environmental managers that the lack of a clear national policy on marine science has been a serious impediment to its development(63). The Resource Assessment Commission's Coastal Zone inquiry was highly critical of the lack of emphasis on applied research, for example the production of coastal zone inventories and long-term monitoring programs. It also noted that access to information by local council environmental managers is generally poor(91). However, various scientists contributing to SOMER argued that more basic research was needed as we must understand the functioning of marine communities before we can manage human impacts(7-14).

SOMER found that a large body of information does exist for a few places, such as the Sydney region and Port Phillip Bay and Western Port in Victoria. However, in most cases this was unpublished, was of varying quality, and has never been collated and interpreted.(63)

SOMER also suggests that a significant gap exists between marine science and marine environmental management in Australia, reflecting that perennial barrier between science and management. As a consequence, existing scientific knowledge has not been adequately applied in marine environmental management. Cooperative Research Centres which involve science, industry and management are an important recent initiative to overcome this problem.(63)

A national state of the environment reporting program is being established by the Commonwealth government(94). This will require quantitative, statistically-based, long-term monitoring using a nationally agrees set of indicators.

report card: pollutant levels in Austraia's marine environment

Report card: pollutant levels in Austraia's marine environment

report card: water quality in the marine environment

Report card: water quality in the marine environment

report card: state of scientific knowledge of the marine environment

Report card: state of scientific knowledge of the marine environment