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Dredging on the Great Barrier Reef: Can resource use and conservation co-exist?- Malindi Gammon


The Great Barrier Reef is a multi-use marine park in which conservation is combined with resource use such as commercial fishing and tourism. Plans to expand an existing coal port within the region have recently been approved. The government plans to coincide such resource use with conservation, ensuring any adverse environmental effects are avoided or mitigated.        However, several factors surrounding the approval of Abbot Port expansion are in conflict with core conservation values: 1.) The reef is already in a state of jeopardized health as a direct result of anthropogenic stressors, 2.) The expansion will lead to some ongoing effects which can’t be mitigated and 3.) The expansion is to allow for capital investment in coal energy, an unsustainable energy source. In the instance of Abbot Port expansion, resource use and conservation can not co-exist.


The Great Barrier Reef (GBR) is a world Heritage site acknowledged for its outstanding global significance to biodiversity. Covering over 348,000 square kilometres, the Great Barrier Reef (GBR) encompasses approximately 3000 reefs and represents 10% of the world’s reefs (GBRMPA, 2009). The GBR is home to many unique and endangered species, including over 1500 species of fish, 350 species of hard coral, 6 of the world’s 7 species of marine turtle, the dugong and more than 30 species of whale and dolphin (Wachenfeld et al, 2007). The GBR is a delicate ecosystem, existing on a fine balance between the marine environment and the interactions of all species living there. This balance creates a spectacular array of colour and life forms, upon which Australia has built its international identity (Figure 1).           The value of the GBR isn’t restrained to its ecological value, it also holds immense monetary value and resources. The GBR is a multiple use marine park which is open to sustainable resource use and supports a commercial marine tourism and fishing industry. An estimated 6 million tourists visit the GBR annually, contributing $6.1 billion dollars to the Australian tourism industry (Wachenfeld et al, 2007). 


Figure 1: This photo illustrates the amount of life which exists even within a small sub-section of the vast reef. Small reef fish are taking refuge in stony coral whilst larger fish school above. Retrieved from:

On 10 December 2013 the Australian government approved a dredging programme for proposed terminals at the Port of Abbot, a port which is located within the Great Barrier Reef Marine Park and used for the exportation of coal (MFE, 2013a). This proposal included the dredging of up to 3 million cubic metres of spoil (sand, silt and clay off the seafloor) and the disposal of this 24km off-shore from the dredging site (MFE, 2013b). The decision to approve this project has not been taken lightly, and the conclusion was reached under the agreement of 47 strict environmental conditions, including:  150% net benefit requirement for water quality, approximate monetary contribution to projects supporting reef health of $89 million and measures for protection of marine species and communities (GBRMPA, 2009). Despite these stringent conditions, the approval has been met with a fierce public debate (Fig. 2).


Figure 2: A crowd protests the approval of dredging at Point Abbot and dumping of spoil within the Great Barrier Reef Marine Park. Photo: The Cairns Post, February 04 2014.

Prior to approval, the proposal attracted 228 submissions in opposition (The Department of State Development, Infrastructure and Planning, 2013). These submissions, were from individuals, consultancies and both nongovernmental and governmental organisations and cited adverse environmental impacts as a primary cause for concern (The Department of State Development, Infrastructure and Planning, 2013). The GBR Marine Park Authority aims to balance economic development with environmental protection, stewardship and conservation. I pose the question of whether resource use and conservation can co-exist in the context of dredging on the GBR, as it has done in the past with commercial fishing and tourism.


Two sides to the debate:

The Australian economy stands to benefit substantially from the proposed dredging and expansion of Abbot Port. Expected outcomes include: an additional $660 million of revenue per year, $123 million household income per year and 2,300 full-time jobs (Ports Corporation of Queensland, 2008). In addition to the massive economic gain, stringent environmental conditions have been set in place to limit negative impacts.  In his press release the Minister for the Environment Hon. Greg Hunt, stated that the approval was granted under strict environmental conditions to avoid, remedy and mitigate any adverse environmental impacts (MFE, 2013). In particular, the condition to ensure net water quality state of 150% its current state, will greatly improve the quality of water within GBR to a level beyond what it is currently. Terrestrial run-off of polluted water and its effect on water quality has a significant adverse effect on many species within the GBR (Schaffelke et al, 2005). The outcome of this is to ensure a positive gain, both environmentally and economically, from this proposed development.               A 2009 outlook report for the GBR cited climate change (increasing sea temperature, ocean acidification and rising sea level), catchment runoff, sedimentation and coastal development as the greatest threats to the health of the GBR (GBRMPA, 2009). The effects of dredging and mining on the reef were not cited as a major source of degradation, a fact dutifully mentioned by those in support of the Port of Abbot expansion. The minimum $89 million contribution to support projects aimed at reef health could make steps towards researching and mitigating these major causes of decline.

When considering the effect that the Abbot Port expansion may have on the GBR, we must first consider the ecosystems current state of health and it’s resilience to environmental stressors. This ecosystem is already exposed to a multitude of anthropogenic stressors, both direct and indirect:  Ocean acidification (De’ath et al, 2009), large scale-bleaching events (Berkelmans et al, 1999) and rising sea water temperatures (Hoegh-Guldberg et al, 2007). All of these factors have led to a loss of over half the initial coral cover since 1985 (De’ath et al, 2012) (Fig. 3)



Figure 3: Box plots of the percentiles (25%, 50% and 75%) of coral cover distributions within each year at the GBR. A significant decline since 1985 is evident of 28% coral cover to 13.8% coral cover (De’ath et al, 2012).

Not only is the reef in a state of jeopardised health, but, despite attempts to alleviated and mitigate any adverse effects during dredging and construction, the reef is still likely to be negatively impacted. Some species of coral are very sensitive to sedimentation. Sedimentation will result during dredging, and dumping due to a large expanse of fine particles being released into the water column. Certain coral species can be extremely sensitive to the sedimentation of disrupted spoil during dredging (Erftemeijer et al, 2012). Due to the varying tolerance of many coral species, some corals will be extremely sensitive to sedimentation, whilst those with a greater tolerance will likely thrive in the absence of less tolerant species. This could cause a shift in the community composition towards a dominance in sedimentation resilient species (Sofonia et al, 2008).  Such a shift in coral community dominance could have a bottom-up effect on the wider community and those species which rely on particular coral as a form of nutrients and protection. Although such an extreme effect is unlikely, affected corals are in a prior state of stress and we do not know how close to their maximum tolerance levels they may be.                   The dredging is part of an expansion plan for Abott Port, a port used in the exportation of coal. If this expansion were to occur, more coal transporting vessels will pass through and within the vicinity of the reef. Juvenile reef fish use sound created by the reef to locate habitat and settle (Radford et al, 2011). Sound created by coal transporters would likely “drown-out” the sound of the reef and limit fish larvae’s ability to locate and settle on the reef (Holles et al, 2013). An increase in shipping traffic would also increase the chance of invasive species introduction via ship ballast waters (Lavoie et al, 1999). Both these factors are outcomes which need to be considered carefully as there impacts go well beyond the initial stages of development. Not only will dredging cause an initial and ongoing disturbance to an ecosystem which is already under considerable anthropogenic stress, but the dredging is being undertaken to expand investment into an unsustainable resource, coal. Consideration has to be given to the affect such an investment will have on current attempts to mitigate climate change and shift toward renewable sources of energy.


The approval of Abbot Port expansion was not met without careful environmental consideration and stringent conditions aimed to protect the environment and mitigate any negative impacts. If the GBR where existing in isolation, sealed off from current environmental issues plaguing the world, then these conditions would likely suffice. However, this is not the case. The GBR is already subjected to immense anthropogenic stressors as evident by mass bleaching (Berkelmans et al, 1999), reduction in coral cover (De’ath et al, 2009) and a general decline in reef health. All these factors have reduced the resilience of the reef, and any further impact should be avoided.     Several outcomes of the Abbot Port expansion are at conflict with conservation values. Despite best-practise attempts to reduce any sedimentation effects, some is likely to occur. Many coral species are sensitive to sedimentation (Erftemeijer et al, 2012) and due to the current state of reef health (De’ath et al, 2012) we don’t know how resilient these species may be. Some ongoing effects can not be remedied, especially the effect additional boat noise may have on larvae settlement (Holles et al, 2013). Finally, the dredging is to allow for the expansion of a port which is used for the exportation of coal. Coal, being a fossil fuel, is an unsustainable energy source. The combustion of coal contributes greatly to global pollution and carbon dioxide level, both of which have put the GBR under considerable stress. Can resource use and conservation co-exist in the context of dredging on the Great Barrier Reef? My answer is No.


Australian Government: Great Barrier Reef Marine Park Authority (GBRMPA). (2009). Great Barrier Reef Outlook Report 2009: In brief. Great Barrier Reef Marine Park Authority: Queensland, Australia.

Australian Government: Ministry for the Environment (MFE). (2013a). Abbot Point and Curtis Island projects approved- New safeguards to protect the long-term future of the Great Barrier Reef. [Press release]. Retrieved from: Retrieved on: 02.04.2014.

Australian Government: Ministry for the Environment (MFE). (2013b) Abbot Point and Port of Gladstone Projects Summary. [Press release]. Retrieved from: Retrieved on: 02.04.2014.

Australian Government: Great Barrier Reef Marine Park Authority (GBRMPA). (2014). Permit G14/34897.1. Retrieved from: Retrieved on: 02.04.2014.

Berkelmans, R., & Oliver, J. K. (1999). Large-scale bleaching of corals on the Great Barrier Reef. Coral reefs18(1), 55-60.

The Department of State Development, Infrastructure and Planning (2013). Great Barrier Reef Ports Strategy Consultation Report Version 1.1, summary of consultation responses. Australia: Queensland.

De’ath, G., Lough, J. M., & Fabricius, K. E. (2009). Declining coral calcification on the Great Barrier Reef. Science323(5910), 116-119.

De’ath, G., Fabricius, K. E., Sweatman, H., & Puotinen, M. (2012). The 27–year decline of coral cover on the Great Barrier Reef and its causes.Proceedings of the National Academy of Sciences109(44), 17995-17999.

Erftemeijer, P. L., Riegl, B., Hoeksema, B. W., & Todd, P. A. (2012). Environmental impacts of dredging and other sediment disturbances on corals: a review. Marine Pollution Bulletin64(9), 1737-1765.

Hoegh-Guldberg, O., Mumby, P. J., Hooten, A. J., Steneck, R. S., Greenfield, P., Gomez, E., & Hatziolos, M. E. (2007). Coral reefs under rapid climate change and ocean acidification. science318(5857), 1737-1742.

Holles S., Simpson S. & Radford A. (2013). Boat noise disrupts orientation behaviour in coral reef fish. Marine Ecology Progress Series 485: 295-3000.

Lavoie, D. M., Smith, L. D., & Ruiz, G. M. (1999). The potential for intracoastal transfer of non-indigenous species in the ballast water of ships. Estuarine, Coastal and Shelf Science, 48(5), 551-564.

Ports Corporation of Queensland (2008). Report for Abbot Point Coal Terminal X110 Expansion. Australia: Queensland. [Retrieved from:].

Radford, C. A., Stanley, J. A., Simpson, S. D., & Jeffs, A. G. (2011). Juvenile coral reef fish use sound to locate habitats. Coral Reefs, 30(2), 295-305. 

Schaffelke, B., Mellors, J., & Duke, N. C. (2005). Water quality in the Great Barrier Reef region: responses of mangrove, seagrass and macroalgal communities. Marine Pollution Bulletin, 51(1), 279-296.

Sofonia, J. J., & Anthony, K. (2008). High-sediment tolerance in the reef coral< i> Turbinaria mesenterina</i> from the inner Great Barrier Reef lagoon (Australia). Estuarine, Coastal and Shelf Science78(4), 748-752.

Wachenfeld, D., Johnson, J., Skeat, A., Kenchington, R., Marshall, P., & Innes, J. (2007). Introduction to the Great Barrier Reef and climate change. Climate change and the Great Barrier Reef: a vulnerability assessment, 1-13.


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