The major stresses to Australian reefs are natural, such as cyclones, coral bleaching and crown-of-thorns starfish. Human stresses are minimal, except on some reefs close to the land, because population density is low, the economic status is high, and there is low fishing pressure. Major research is now under way to ensure that fishing is sustainable for target species, for the total catch taken, and for the health of the reef ecosystem. All Australian reefs are under efficient management with strong local support, and good compliance which has achieved more by education and involvement, than by strict enforcement. The bulk of the Great Barrier Reef (GBR) is in good condition because most of it is remote from land influences, but inner shelf reefs may have suffered impacts resulting from increased sediment and nutrient runoff caused by cattle grazing and sugar-cane growing. However the farming industry is working to reduce impacts out of both self interest and concern for the environment to minimise sediment and nutrient runoff into GBR waters. Most towns along the coast are upgrading sewage treatment to secondary level and all tourist resorts are now required to treat sewage so as to avoid any runoff, and to manage the areas of reefs that they use. Reefs off western Australia are in good health as they are generally not impacted by land influences, and there have been no impacts attributed to petroleum exploration or fishing. There is strong recognition by government that the tourism and resource values of coral reefs are particularly high, which means that management receives sufficient attention.

Australia has more reefs under its control than any other country. Most reefs form part of the Great Barrier Reef (GBR) which is probably the best known reef system in the world. All of the GBR is now incorporated in the Great Barrier Reef Marine Park, which contains about 2800 separate reefs along about 2000 km of coastline in an area of 350,000 km² of broad continental shelf. The GBR is not just a barrier reef, but a complex pattern of barrier, platform, patch and fringing reefs growing on the Australian continental shelf, which is narrow (less than 20 km) in the north, broadening to over 100 km in the south. These reefs have very high diversity with about 350 species of coral (compared with the maximum of about 450 species in Indonesia) and estimates for fish species vary from 1200 to 2000. There are also extensive areas of coral reefs in the Coral Sea between New Caledonia and Australia.

Off the western coast of Australia, the reefs are not nearly as extensive and abundant as on the GBR, but cover a range of types including mainland fringing reefs such as Ningaloo, oceanic reefs in the Timor Sea and Indian Ocean such as Cocos-Keeling and Christmas Islands, shelf-edge reefs such as Rowley Shoals, Ashmore, Scott, Seringapatam, and island reefs such as Kimberley, Dampier Archipelago, Houtman Abrolhos.

There is little reef development along the northern Australian coastline, which has a relatively low population, but there are numerous fringing reefs around islands and coral growth on hard bottoms. However, there are some pressures, including commercial fishing, prawn trawling and traditional use.

On average, the major stresses to virtually all of these reefs are natural as human pressures are relatively light. The Australian continent has the lowest population density of any large area on earth (with the exception of the Antarctic) and few of these people live near the tropical coastal areas. The reefs of Australia are generally in good to excellent condition, and the major factor to keep them that way is strong management of virtually all the reefs around the continent and strong public support for reef conservation.

Australian reefs, particularly the Great Barrier Reef, are critical refuges for dugongs and sea turtles, as populations of these endangered animals are being greatly reduced in waters to the west, north and east of Australia through subsistence and commercial harvesting. There are significant populations in Australia for four out of the six major species of turtle, which are threatened elsewhere in the world by unsustainable levels of harvesting. The sheltered reef waters are major breeding grounds for humpback whales. Conservation of these animals forms a major priority in government plans for the management of coral reef resources.

The distribution and abundance of most of the major animals and plants is well known on the GBR and, to lesser extent, on other reefs. Other than Hawaii and Florida, this is a rare situation for coral reefs around the world. Few of the major resources are threatened and populations appear stable.

Cyclones occur relatively often on both sides of Australia and cause major local damage to coral reefs. In addition there is considerable fresh water runoff, with increased sediment and nutrients as a result of these cyclones on the east coast. The crown-of-thorns starfish and coral bleaching have caused major damage to Australian reefs in the past 30 years and currently the reefs are recovering from a major bleaching event this year. Some reefs close to shore were severely impacted with high coral mortality, but most reefs suffered only minor damage.

Although most of the reefs of the GBR are a long way offshore, sediment and nutrient pollution are the major threats to the inner reefs. The largest sources of sediment are from two major rivers that drain large areas of dry, cattle-grazing lands, as well as many shorter coastal rivers that carry flood waters during wet seasons. Heavy rains after drought have resulted in major outflows of sediment into the GBR Lagoon (the waters between the reefs and the coast, an area 2000 km long by 20–100 km wide), which damages inner and possibly affects some middle-shelf reefs. The farming industry is developing practices to reduce their own soil losses and at the same time reduce damage to the reefs from excess sediment runoff. This situation does not arise off the western coast of Australia where there is scant agriculture and particularly low rainfall on the land adjacent to the reefs.

Human pressures on the reefs are low, because the population density is low, the reefs are mostly remote from the coast, and fishing pressures are moderate to slight and in some areas virtually non-existent. For example, the offshore atoll reefs on both coasts are so remote from the mainland influences that they are only subject to occasional fishing for prized target fish.

The major sources of nutrient pollution (nitrate and phosphate) on the GBR are from cattle grazing, cane and banana farming, domestic sewage, and tourist activities in that order. Vigorous education and extension programs run by the Departments of Agriculture and the reef managers have raised awareness and led to improved practices in the rural sector. Unmanageable delivery through extreme flood events may be the major source of sediment and nutrient pollution. Cane and banana farmers are regulating their use of fertiliser to minimise runoff loss. Most farmers, including many who are also keen fishermen on the reefs, have changed to green tillage of crops (leaving the trash on the ground as compost and not burning crops). This can reduce sediment loss from cane fields by 20 to 100 times. All tourist resorts treat sewage so that there is no pollution (tertiary treatment).

There is some subsistence fishing on the remote reefs off Western Australia; some is permitted under agreements between Indonesian and Australian governments; but in other areas, there are continuing problems (mostly legal and political) of small-scale poaching of shark, fish, trochus, giant clams and sea cucumbers.

The status of the GBR can be summarised using the four sections in the original declaration of the GBR Marine Park in 1975. Each section is huge and contains hundreds of coral reefs, thus comments on reef condition are based on observations of a small proportion of the reefs. About 20% of the more than 2800 catalogued coral reefs in the GBR are submerged reefs or shoals, while about 26% are fringing reefs around continental islands or along the mainland coast. The remaining reefs are typical carbonate rock platforms rising up from the continental shelf.

Corals and reef fish have been well studied on the GBR, showing that coral cover decreases and then increases quite dramatically after cyclones, crown-of-thorns starfish and coral bleaching, but there are no long-term declines in coral cover or diversity. Even on inshore fringing reefs, where human impacts are highest, there are no indications of any general decline over the last 10 years.

Most coral reefs have about 30% coral cover on average, and rarely do reefs exceed 60% coral cover. This is a result of normal variations and natural ‘wear and tear’ on the corals and reefs. Coral cover on inshore reef slopes at 5 m varies from 50% to 90%, whereas the reef flats are frequently dominated by macroalgae (particularly Sargassum) and about 5% hard coral cover. Coral cover on offshore reef flats is often higher than on nearshore reefs, but cover on slopes is lower (average 29%). Reef fish populations fluctuate naturally because of changes in annual recruitment. Studies do not indicate any long-term major impacts from line fishing on reefs.

This section extends over 400 km from Proserpine (21^oS) to Bundaberg (around 24o30’S) and contains several hundred coral reefs ranging in size from less than 1 km² to over 200 km². Most (around 90%) of the reefs are more than 100 km offshore. The reefs in the north form a dense, complex, and reticulate matrix, while in the south, the reefs are small, discrete and very open to oceanic influence. There is major commercial and recreational fishing with no apparent damage to the reefs or fish populations. The sea floor is trawled for prawns and scallops. The effects of fishing on target fish, bycatch and the ecosystem are being studied.

The adjacent coast is a diverse mix of wetlands, lowland sugar-cane farms and lowland and upland grazing, as well as several ports and towns. These activities may influence the amount of sediment and nutrients flowing into this section of the GBR, but the dominant influence on the nearshore reefs are the strong tide and wind currents and waves that regularly re-suspend the bottom sediments and spread them over the continental shelf. There are many coral reefs that are adapted to growing in this turbid water, and these vary with time, depending on the major floods. In 1990, a major flood of Queensland’s second largest river — the Fitzroy caused localised coral death on nearshore island fringing reefs that has been slow to recover.

Cyclones are common in this section, but surveys indicate that the outer reefs have consistently high coral cover, the highest for the whole GBR. Crown-of-thorns starfish have caused localised reductions in coral cover on some reefs in the north and south over the last 20 years and major bleaching of shallow corals occurred on some offshore reefs in early 1998.

This section starts near Innisfail (17^oS) and extends for 400 km to Proserpine (21^oS). There are several hundred coral reefs ranging from less than 1 km² to over 200 km² with around 90% of reefs more than 50 km offshore in a matrix that is very open to oceanic influence. Major commercial (including bottom trawling for prawns and scallops) and recreational fishing apparently has little damaging effect on the reefs. There are ten coral reef no-fishing, no-collecting areas up to 100 km² in area, and the effects of reef fishing on target fish, bycatch and the reefs are being checked.

There is a mix of rich wetlands, agriculture (lowland sugar-cane farming and extensive upland grazing) and developments, including the port city of Townsville and several smaller towns. These activities have added considerable sediments and nutrients to the waters, but there have been only minor effects on coastal reefs. Coral reefs grow in these nearshore turbid waters, except around Queensland’s largest river, the Burdekin, and these reefs are well adapted to resuspended sediments. There are many tourist resorts and much boating activity in the Whitsunday Islands, and management is designed to protect the reefs while allowing reasonable access.

Cyclones and crown-of-thorns starfish caused major reductions in live coral cover in the last two decades. High densities of the starfish began in the north in the early 1980s and progressed southwards by larval dispersal by the mid- to late-1980s. There was high coral mortality and reductions in coral-feeding fish. But there was strong re-growth of fast growing corals and coral-feeding fish in shallow water, but deeper slopes and areas dominated by slow growing corals are recovering more slowly. A new outbreak of the starfish is now starting in the northern section, and major coral bleaching in 1998 caused high mortality in shallow parts of middle shelf, nearshore and island fringing reefs north of Townsville.

This starts north of Lizard Island (14^oS) down to Innisfail (17o30’S), and contains several hundred reefs from small (1 km²) to large (over 100 km²) along the 400 km section. The mid-shelf part is a dense, complex matrix of reefs sheltered from ocean waves by an outer barrier reef, broken only by narrow passages. There are 30 preservation zones (no-take areas) up to 75 km², mainly on reefs. The continental shelf is narrower and about 90% of the reefs are within 20 km of the coast. This area is heavily used by tourists, and is extensively fished commercially and recreationally.

The coastal plain is narrow with large areas of sugar-cane farming, adjacent to an extensive world heritage area of rainforests on low mountain ranges. Beyond this there is extensive upland agriculture and grazing in the water catchments. The Great Barrier Reef’s major tourism centres for day trips and live-aboard trips to the reefs are Cairns and Port Douglas. Nearshore reefs are limited in number and extent because of high rainfall and moderately high human population densities, and the corals have been damaged by increased sediments and nutrients coming from the rivers. Reefs in the middle of the section were impacted by sediments from a controversial rainforest road built in the 1980s, but there is no evidence of major long-term changes. In the far north are major silica sand dunes that provide a less turbid nearshore environment.

Cyclones are common, and crown-of-thorns starfish have caused reductions in live coral three times in the last 30 years, each time followed by strong coral recovery. The major tourist reefs were either not affected or were protected by starfish collection programs after early warning from government reef monitoring programs. In the southern half, coral cover on 31 reefs declined from the high 20%s to the low 20%s from the mid-1980s to mid-1990s, in parallel with increases in starfish of from 5% to 40%. However, coral cover increased in the northern half of the section, despite similar numbers of starfish. This is probably the ‘primary outbreak’ region for crown-of-thorns starfish, because all recent outbreaks were first recorded here. This leads to the suggestion that the outbreaks may be due to human activity because this section has the greatest amount of human activity, and the highest runoff of sediments and nutrients, and these factors may mean that more larval starfish survive, or more starfish predators are removed by fishing. New outbreaks of the starfish occurred in mid-1998. Nearshore and island fringing reefs in the southern part of the section were bleached in early 1998, some with high coral mortality.

This starts at the tip of Cape York (10^o40’S) and extends over 400 km to Lizard Island (14^oS), and contains several hundred reefs ranging from small to large. The continental shelf is narrow and around 90% of the reefs are less than 20 km from shore. There is a dense matrix of reefs sheltered from the ocean by an outer barrier reef with narrow passages. In the north (10^oS to 13^oS), the shelf is over 100 km wide and mid-shelf reefs are more exposed to ocean waves. The land is almost uninhabited with a small amount of cattle grazing and the rest of the coast is either muddy or sandy. There are virtually no tourists and little recreational fishing and diving, but there is significant reef-line fishing and sea-floor trawling.

This section includes the largest no-take area in the GBR Marine Park (more than 5000 km² and across the full 140 km width of the continental shelf). There are also another 20 no-take areas (10–400 km²). Surveys of 30 reefs showed differences between the north and south in the 1990s: low and declining abundance of crown-of-thorns starfish and a high and increasing coral cover in the north; and low abundance of starfish and coral cover declining from mid-30% to mid-20% in the south. Aerial surveys of the 1998 bleaching event indicate most inshore reefs had low levels of coral bleaching while most mid-shelf and offshore reefs had none.

There are a series of atoll-like reefs on a deep shelf between Australia and New Caledonia. These atolls sit in very deep clean water and are under the influence of strong oceanic waves and cyclones. Some reefs have coral cays, which are all uninhabited except for a weather station. The reefs are remote from any land influences and have only minor fishing pressures, and are in virtually pristine condition. Populations of giant clams were heavily poached by ships from east Asia in the 1980s, until enforcement by Australian authorities increased.

Lord Howe Island (31^o40’S) has one of the most southerly coral fringing reefs in the world. This volcanic island (14.55 km²) is 603 km off the east coast of Australia and has fringing reefs with low species diversity, but a good coral cover on the rocky slopes, in passes and lagoons. The island and surrounding seas were declared a World Heritage Area in 1982. There were significant differences in the composition of coral species between 1978 and 1993, suggesting some turnover of rare species. The reef has been subject to crown-of-thorns starfish predation (early 1990s) and coral bleaching (late 1990s), but impacts have been minimal and the condition of the reef is good. Fish, plants and invertebrates have a mix of tropical and temperate species and a number of endemic species. There is a management plan to protect the area’s World Heritage values while allowing recreational fishing, and fishing to supply locals and tourists.

Elizabeth and Middleton Reefs are large atolls situated about 120 km north of Lord Howe Island. Surveys in the 1980s and 1990s showed there was more diversity and more tropical species than on Lord Howe. Crown-of-thorns starfish did some damage throughout the 1980s, but the full impacts are not known. Human impacts are negligible, but storms and occasional shipwrecks do have local impacts.

These isolated oceanic and shelf-edge reefs are far from any mainland influence, being scattered between 12^oS and 18^oS along a line 400 km from the northwest Australian coast. Ashmore Reef (12^oS) is closer to Indonesia than Australia and is regularly fished by Indonesians under conditions agreed by both governments. Scott Reef (14^oS) is visited less frequently by Indonesians, and is a prospective site for extraction of liquid natural gas. Rowley Shoals (17^oS) are protected as State and Commonwealth marine parks. Trochus, trepang (sea cucumbers), and shark and other fish are harvested, but the effects on the reefs are unknown. All reefs have hard coralline algae pavements and low and stunted corals in exposed high wave-energy areas, and high coral cover and a large variety of growth forms in sheltered habitats. The condition of the coral communities at all reefs was good through most of the 1990s. However Scott Reef was bathed in warm water and seriously bleached, with high coral mortality to depths of more than 30 m during 1998.

These are particularly isolated reefs in the Indian Ocean, much closer to Indonesia than Australia. The Cocos-Keeling Islands are atolls south of Sumatra at about 12^oS and the Christmas Islands are a terrestrial park (due south of Java) which predominantly have fringing reefs. Population density on both groups is very low (600–700) and has a low impact on the reefs, except for some over-harvesting of some molluscs (Lambis lambis). The Cocos-Keeling Islands have been proposed as an Australian protected area. The reefs are in virtually pristine condition, but there were reports of two large-scale coral die-offs in the past, with significant recovery of the corals afterwards.

These reefs and islands (21^oS) are on inshore and mid-shelf parts of the continental shelf, respectively. There is high diversity and abundance of corals and fish, and despite increasing pearling, petroleum, fishing and tourism activity, there is no evidence of significant human damage to the reefs. The Monte Bellos were used for British Nuclear tests from 1952–1956.

The Ningaloo Marine Park extends from 22^oS, southwards for about 230 km. There is a long fringing reef, separated from the shore by a 3 km wide sandy lagoon. All this is adjacent to a desert, which is unlike the eastern side of Australia. Coral and fish communities are diverse and abundant and fishing is only permitted in parts of the marine park. Outbreaks of a coral-eating snail (Drupella) killed much of the coral in some areas in the 1970s and 1990s, and other areas have been damaged by low oxygen conditions when coral spawn decomposes. Now, new corals are recruiting and restoration of coral cover is progressing, but many areas are still dominated by dead coral and rubble. A broad-scale monitoring program has recently been established.

The Abrolhos Islands and coral reefs (28^oS) are the southern limit of reef development in western Australia. The reefs, which have extensive areas of both kelp and corals, are the site of a major and well-managed rock lobster industry worth AUD$13.5 million per year. The use of lobster traps is banned from areas with fragile corals, and there is no indication of any widespread detrimental effects on the coral and fish communities. These reefs are in good to excellent condition and plans have been prepared for declaring the area as a marine protected area. There is extensive oil and gas potential in offshore areas, and this may be an important test case for the coexistence of an oil industry and productive coral reefs.

There is coral growth on rocky reefs south of the Great Barrier Reef in southern Queensland Gneering Shoals (26^oS), Flinders Reefs (27^oS) and northern New South Wales (28^o30’S) on rocky reefs with populations of corals up to 50% coral cover.

There are also large areas of sparse coral communities, but with low coral cover in northern Australia around Darwin. Many of these areas are dominated by soft corals and gorgonians. A major protected area is the Coburg Peninsula Marine Park and Sanctuary, which is managed by the Northern Territory Conservation Commission.

The reefs in Australia are well managed and are seen to be under no immediate threat of widespread degradation from use and impacts by local communities, although some scientists are concerned there could be long-term damage caused by aspects of global climate change. In 1975, the Australian and Queensland state governments set up legislation to manage the whole area of the GBR and established the Great Barrier Reef Marine Park Authority (GBRMPA) which has responsibility for the World Heritage listed GBR Marine Park. This was immediately after an active public campaign to stop oil drilling and mining on the GBR. The Act of Parliament listed the task of planning and managing the GBR as: ‘to provide for the protection, wise use, understanding and enjoyment of the Great Barrier Reef in perpetuity through the care and development of the Marine Park’. The environment department of the State of Queensland has responsibility for day-to-day management of the GBR Marine Park, such as enforcing fishing regulations; while GBRMPA is responsible for policy and strategic management, including giving permission for tourism activities in the park and directing some research and monitoring. The primary methods of management are restriction of use in some places by creating zones and management plans, and regulating reef use through issuing permits. Mining and oil drilling are prohibited in all parts of the marine park. Commercial use of the marine park requires a permit, and must be consistent with zoning and management plans.

There are many reasons why managing the Great Barrier Reef (GBR) has been different to managing other areas:

• the GBR is a very large system (2000 km long) and most parts are closely connected by currents which supply fresh larvae;
• most reefs of the GBR are remote from land (more than 30 km offshore);
• population density on the nearby coast is very low;
• fishing and other exploitation is moderate and there is no subsistence fishing;
• the economic status of the local population is relatively high;
• the local people have a high conservation ethic and strongly support the need for management;
• there is strong support from all levels of government and there are adequate funds for effective management;
• there is a strong marine and social science community able to provide valuable data and support for management.

Management of the GBRMP has been facilitated through extensive consultation with local populations, farmers, fishing groups (both recreational and commercial), the tourist industry, NGOs and the indigenous communities along the coast. All these people are represented on a special advisory body (Consultative Committee), which provides direct advice to the senior committee (The Authority) which contains a representative of the Australian Government, the State Government of Queensland, a representative of the broader community and a representative of indigenous peoples.

A special feature of the GBRMP, compared to other types of protected areas (e.g. national parks), has the division of the area into seven different zones. The zones are designed to cater for all users and also to ensure that significant areas are conserved and protected. The major activities being controlled are fishing, collecting and tourism. The major direct human threat to the areas surrounding the reefs is fishing by trawlers. In 1981, it was proposed that at least 10% of the sandy bottoms would be closed to fishing, now the figure is 15% to 30%.

There are two zones for the sandy bottoms around the 2800 reefs:

• in 80% of the area (General Use Zone), trawl fishing is permitted;
• in the remaining 20% (Habitat Protection Zone and other categories), trawling is banned.
• On the reefs, there are four zones:

Tourism is allowed in all zones, except the Preservation Zone, however, operators can place floating tourist pontoons on about 60% of all reefs, usually only one structure being allowed on each reef. Currently about 16% of the reefs in the marine park are zoned to prevent any extractive activities. All zones are protected by legislation and are intended to remain unchanged for five years, after which they can be renegotiated and re-zoned for a similar period. GBRMPA has continuing government funding, which is now supplemented by a day fee of AUD$6 for all tourists visiting the reef.

Management of western Australian reefs is carried out by the Environment Protection Agency for environmental impact assessment, and by the Conservation and Land Management Department of the Western Australian state government, which is responsible for declaration and management of marine protected areas. The management status of the reefs and the capacity on the ground are good, but many proposed MPAs have not yet been implemented. There are important potential threats from oil industry activities, but no major degradation has been recorded so far.

The outlook for the reefs of Australia is very good. The appreciation of the reef resource and support for its management will increase as the population grows relatively slowly and economic conditions improve for the people. This will mean that greater resources will be put towards improving management and decreasing human pressures on the reefs, for example improving agriculture and grazing practices to reduce sediment and nutrient flows onto the GBR.

Also there is an increased appreciation of the value that coral reefs bring to the Australian economy, particularly in attracting international tourists. Reef management is backed up by very strong research capacity at the Australian Institute of Marine Science, at James Cook and other universities and in other arms of government. There are also strong social science and policy studies conducted by GBRMPA, government departments and universities.

Terry Done leads two coral reef research groups, one at the Australian Institute of Marine Science and the other at the Reef Cooperative Research Centre, a body that brings tourism and other industries into research and management; Clive Wilkinson coordinates the Global Coral Reef Monitoring Network based at AIMS. We thank the following colleagues for comments and information: Jamie Oliver from GBRMPA; Hugh Sweatman and Andrew Heyward from AIMS; Vicki Harriott and Peter Harrison from the Southern Cross University; Chris Simpson from the Western Australian Department of Conservation and Land Management.