by Louise Goggin
The Great Barrier Reef World Heritage Area stretches over 2,000 kilometres along the Australian coastline and reaches from the low water mark on the Queensland coast to beyond the outer barrier reef. It covers an incredible 348,000 square kilometers, an area bigger than Italy.
The Great Barrier Reef World Heritage Area (GBRWHA) comprises the largest coral reef ecosystem that has ever existed—as well as mangroves, rocky reefs, sandflats, open ocean and the deep sea floor. It is home to approximately 500 species of seaweed, 4,000 species of mollusks, 400 species of coral, 1,500 species of fish, 20 species of sea snakes and over 200 species of birds, as well as some of the largest populations of dugongs in the world. There are also about 30 species of whales, dolphins and porpoises that visit or live in reef waters.
In addition to its exceptional natural biodiversity, the GBRWHA has a rich cultural heritage and has been an integral part of the social, economic and spiritual life of Aboriginal and Torres Strait Islander peoples for thousands of years.
Because of its unique national and international significance, the Great Barrier Reef was listed under the World Heritage Convention in 1981. It met all four of the natural heritage criteria: biological diversity, aesthetics and natural beauty, ecological and biological processes, and geological phenomena. Given its listing as a World Heritage Area, Australia ensures that this complex and beautiful ecosystem is protected and conserved for future generations.
The Great Barrier Reef has many features that help to protect it, giving it a natural advantage over some other reef systems around the world (Maniwavie, et. al., 2000; Reichelt, 2001).
These features do not guarantee the reef will remain in a healthy state into the future. The Great Barrier Reef is currently under threat from pressures from adverse water quality, as well as significant medium to long-term threats from global warming. In Australia, increasing populations adjacent to the Great Barrier Reef, and increasing pressure from unsustainable fishing and tourism impacts in specific high use areas, will need to be managed.
Balancing Many Uses
The Great Barrier Reef World Heritage Area is almost entirely protected within the Great Barrier Reef Marine Park (GBRMP), which was established in 1975 and is the world’s largest marine protected area.
Unlike many marine parks around the world where extractive activities such as fishing and collecting are not allowed, the GBRMP was set up as a multiple-use marine park. It allows and manages reasonable commercial and recreational uses and, at the same time, protects and conserves biodiversity. The GBRMP supports major industries such as ports, shipping, tourism and fishing. These industries are important economically for Australia. Reef-based tourism is estimated to be worth more than A $1 billion a year and commercial fisheries worth about A $400 million a year. In addition, recreational fishing and boating is intense.
In the GBRWHA, these diverse and sometimes conflicting activities are managed in a co-operative and integrated way by State and Commonwealth agencies. The Great Barrier Reef Marine Park Authority (GBRMPA), a Commonwealth statutory authority, has responsibility for planning and managing the marine park while field-based, day-to-day management activities including enforcement, surveillance, monitoring and education are jointly funded and conducted primarily by Queensland agencies. Agencies that help manage the Marine Park include the Queensland Environment Protection Agency, Queensland Department of Primary Industries, Queensland Boating and Fisheries Patrol, Australian Federal Police, Queensland Water Police, Australian Customs Service (Coastwatch), Australian Maritime Safety Authority and Environment Australia.
The GBRMPA uses several tools to manage the park including regulation, zoning and management plans, permits and community education programs. The system of zones was established under Australian Federal law to protect critical habitats as well as manage human use in the park. Mining and oil drilling are prohibited throughout the marine park. In most zones (95 percent of the park), most commercial and recreational activities, including fishing and diving, are permitted. In other no-take zones (4 percent of the park), extractive activities such as fishing and collecting are not allowed. There is no access to the remainder of the park (less than 1 percent of the park) which are preservation areas, where all activities are excluded.
Although many significant reefs are already included in no-take zones, there was growing concern that protecting less than 5 percent of the park (16 percent of the reefs) in these zones may not be enough to maintain the biodiversity and ecological integrity of the enormous numbers of “less-known or less-spectacular habitats” in the Great Barrier Reef Marine Park for future generations (Maniwavie, et. al., 2000).
In addition, Australia’s Oceans Policy was released in 1998, which committed Australia to accelerating the development of a National Representative System of Marine Protected Areas. The Oceans Policy also required a review of existing protection arrangements to ensure appropriate levels of protection for all habitat types within the Great Barrier Reef World Heritage Area.
The GBRMPA has started a process that will increase the area and number of no-take zones (or marine sanctuaries) to ensure that the ecological processes and systems of the Great Barrier Reef are maintained. A comprehensive network of no-take zones will be developed with representation from all 70 habitats and communities (called bioregions) that were identified in the park. To identify these bioregions, the GBRMPA consulted with more than 70 of Australia’s top scientists, who pooled their vast expertise about the physical and biological diversity in the park. Learn more at http://www.gbrmpa.gov.au.
It will be a few years before the exact area and location of new no-take zones are defined by the GBRMPA. Community consultation will ensure that new zoning plans not only protect representative areas of biological, cultural and historical significance, but where possible, still allow access to regions that are important for recreational and commercial use.
Without a thorough understanding of the biological diversity and ecological processes of the Great Barrier Reef, it would have been impossible to define bioregions in the marine park. Monitoring is also crucial to track changes, such as outbreaks of crown-of-thorns starfish, locate hot spots of coral bleaching, or declines in the status of inshore reefs.
In 1993, the Australian Government established a Cooperative Research Centre (CRC) to focus research in the Great Barrier Reef World Heritage Area. The CRC Reef Research Centre is a collaborative venture of key coral reef managers (Great Barrier Reef Marine Park Authority), researchers (Australian Institute of Marine Science, James Cook University, Queensland Department of Primary Industries), industry associations (Association of Marine Park Tourism Operators, Queensland Seafood Industry Association, Sunfish Queensland, Inc.) and non-government organisations (Great Barrier Reef Research Foundation). Another 50 national and international organisations are also associated with the Centre.
In addition to Australian Government support, funding for CRC Reef Research Centre comes from many other sources including reef industry groups, state governments and research institutions. Each visitor to the reef also pays a small fee, some of which is directed to research by CRC Reef Research Centre. These contributions support more than 80 research tasks and a range of university postgraduate training valued at more than $75 million over seven years.
Through its members, CRC Reef Research Centre coordinates the efforts of hundreds of researchers to provide science to protect, conserve and restore the world’s coral reefs by ensuring industries and management are sustainable and that ecosystem quality is maintained. CRC Reef Research Centre is providing critical research to improve understanding of major issues such as coral bleaching, water quality, crown-of-thorns starfish, and use and conservation of biodiversity.
Pressures on the Reef
While ship groundings, the possibility of oil spills, increasing urbanisation, tourism and fishing pressure are a concern to local areas of the Great Barrier Reef World Heritage Area, the long-term survival of vast areas (particularly inshore) of the Great Barrier Reef is most likely to be threatened by run-off from the land, and global warming. These threats could alter the reef ecosystem that we know.
Most of the 2,900 reefs that form the Great Barrier Reef are more than 20 kilometres from the coast and so are rarely directly affected by the nutrients and sediments that are washed off the land. However, 750 reefs are within 10 km of the Australian coast, with 209 of these reefs in high-risk areas that are regularly affected by run-off.
Inshore reefs have always been subjected to run-off from the land but the sediments, nutrients (nitrate and phosphate) and other pollutants (such as pesticides and heavy metals) in the discharge from rivers and streams has increased four-fold over the last 150 years. The increase is because large areas of native forests and woodlands have been cleared since 1850 for cattle grazing, farming and mining activities. In addition, the advent of drought-resistant and tick-resistant breeds of cattle has enabled farmers to continue stocking in dry periods so that erosion is greatly increased when floods arrive. More land is also under cultivation and more fertilisers are being used on crops so that there is an increasing amount of fertiliser running off the land and onto inshore reefs.
The increasing levels of sediment, nutrient and other pollutants are causing concern for the long-term survival of inshore ecosystems. The increased sediment can smother plants and sessile animals such as corals. The increased turbidity of the water can cut light needed by algae and minute plants in the tissues of corals or giant clams for photosynthesis. Increasing nutrients have the potential to shift the balance in some reef communities and enhance the growth of algae (especially if there are fewer herbivorous fish due to fishing), and animals that can burrow into corals or overgrow them. Excess algae can then overgrow corals. There is mounting evidence that increasing levels of nutrients in run-off may also improve the survival of larval crown-of-thorns starfish so that many more than usual survive, leading to starfish outbreaks.
The greatest concern is that the impacts of increased levels of nutrient and pollutants may not be obvious until inshore systems reach a threshold level after which there is an irreversible decline of near-shore systems and seagrass beds.
Fifteen Australian scientists were so concerned that they wrote in a consensus statement that “there is continued urgency to work towards a reduction in the run-off of sediments, nutrients, herbicides and other pollutants into the Great Barrier Reef World Heritage Area” (read more now).
To address these concerns, the GBRMPA has recommended water quality targets for rivers that flow to the Great Barrier Reef. This is the first part of a staged approach that aims to stop the decline in water quality and eventually allow for the recovery of inshore reef ecosystems. However, the river catchments are outside the legislative boundaries of the GBRMP.
Therefore, the key to halting the decline in water quality is to create partnerships in the community on a scale that has never been done before. This is the concept of the regional management bodies under the Natural Heritage Trust and the National Action Plan for Salinity and Water Quality.
The Australian Federal Government established the Natural Heritage Trust in 1997 to “help restore and conserve Australia’s environment and natural resources”. By 2002, A $1.4 billion had been invested in more than 11,900 projects involving 400,000 people across Australia. The NHT fund will continue until 2007 and has a total budget of A $2.5 billion with at least $350 million likely to be spent to improve water quality. There are four NHT programs: Landcare (promoting sustainable agriculture), Bushcare (conserving habitat for native flora and fauna), Rivercare (improving water quality in river systems) and Coastcare (protecting coastal catchments, ecosystems and the marine environment).
In concert with the NHT initiative, “education and extension programs run by the Department of Primary Industries and reef managers have raised awareness and led to improved practices in the rural sector…. Cane and banana farmers are regulating their use of fertiliser to minimise run-off loss. The practice of green tillage of crops and trash blanketing (leaving the trash on the ground as compost and not burning crops) is increasing, which reduces sediment and nutrient loss” (Maniwavie, et. al., 2000).
In August 2002, the Commonwealth and Queensland Governments announced they had agreed to work together to develop a Reef Water Quality Protection Plan aimed at halting the decline in water quality caused by land-based activities in GBR catchments. The plan would also seek improvements in water quality in the next decade to meet end-of-river water quality targets that would contribute to healthy waterways and inshore reef systems.
Water quality is a major problem in nearshore areas but probably the most difficult and pervasive threat to the Great Barrier Reef comes from a global phenomenon – the warming of our atmosphere and oceans. In 2002, the world’s most comprehensive survey of coral bleaching found that bleaching in the Great Barrier Reef Marine Park may be the worst on record.
The survey by scientists from the Australian Institute of Marine Science, CRC Reef Research Centre and the Great Barrier Reef Marine Park Authority covered more than 640 reefs from the northern tip to the southern end of the GBRMP using light aircraft. The team also used SCUBA to confirm results and determine whether corals were likely to recover from bleaching or would die.
Bleaching is a sign of stress. Corals appear bleached when they expel the tiny plants that usually live in their tissues. High water temperatures and other environmental conditions stress corals and can cause them to bleach. Many corals can recover from bleaching but if temperatures stay too high for too long, the corals will die.
Aerial surveys found that nearly 60 percent of the reef area in the marine park was heat-stressed to some extent as indicated by bleaching. Not all reefs were bleached equally, and the bleaching was not evenly distributed throughout the park.
Until now, the coral bleaching episode in 1998 was the worst on record, but the 2002 event was probably worse because more reef area was affected. The most severe bleaching occurred on reefs close to shore in both bleaching events, but the 2002 event has affected a greater area of reefs further offshore.
Underwater surveys found that few reefs escaped bleaching, but it is likely that most reefs will recover with only minor death of corals. However, some of the most severely bleached reefs were devastated with 50 percent and 90 percent of coral dead at some sites.
Australia has been lucky to see another major bleaching event without widespread death of corals but the devastation we have seen at some sites provides a vivid warning of what could happen if hot water events become more frequent and severe.
It is possible that we may be witnessing the beginning of a slow-motion degradation of the reef system that will only get worse in coming decades. CRC Reef and the GBRMPA will continue to keep a careful watch on the health of the reef and improve our understanding of the implications of global warming for reef management.
Only a commitment by governments around the globe to reduce the volume of greenhouse gases in our environment will ensure that coral bleaching events are not more frequent and more extensive.
In 1998, the Australian Government established the Australian Greenhouse Office which is dedicated to cutting greenhouse gas emissions.
Australia has also signed (although not ratified) an international treaty, the Kyoto Protocol, and is committed to limiting its growth in greenhouse gas emissions to 8 percent above 1990 levels by 2008-2012. At the recent World Summit on Sustainable Development in Johannesburg, enough countries ratified the protocol so that it now comes in to force.
Without the commitment of international governments to reduce global warming, the future for the Great Barrier Reef would be bleak.
The Great Barrier Reef is a national icon for Australians, one that is creating a groundswell of political will to ensure that it is carefully protected. With raised awareness of issues of run-off and global warming and their effect on this national treasure, it is hoped that the Australian people will lobby the Australian Government to ensure that it is protected.