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Dredging the Great Barrier Reef

By: Sarah Stevens

On Friday, January 31, the fate of the Great Barrier Reef will be decided. The question at hand; should permits be issued allowing dredging of the Great Barrier Reef?

Aerial view of the Great Barrier Reef.  Image courtesy of Theo Allofs / Getty Images.

Aerial view of the Great Barrier Reef. Image courtesy of Theo Allofs / Getty Images.

As one of the world’s top coal producers, Australia’s coal exports increased 30% last year, making the push to increase the volume of coal exports highly lucrative and political. In December 2013, the Australian government approved a coal port expansion project at Abbott Point which will require dredging (excavating the seabed and then relocating it) 3 million cubic meters into the Great Barrier Reef World Heritage Area. To give you some perspective, three million cubic meters is equivalent to over 150,000 tons, and would fill 150,000 dump trucks.

The additional export terminals will increase the country’s annual export by creating infrastructure (railroads and ports) to increase coal output from the Galilee Basin, a coal rich geological depression that until now has been limited by a lack of export infrastructure. In addition to ports, railways connecting the Basin and coast will be constructed as well as “shipping highways” going directly through the Great Barrier Reef. It is estimated that the number of ships traveling through the Reef will increase from 1,722 (in 2011) to over 10,000 by 2020.

Graphic illustrates the impacts of the coal port expansion project.  Image courtesy of Global Social Change.

Graphic illustrates the impacts of the coal port expansion project. Image courtesy of Global Social Change.

Despite Environmental Minister Greg Hunt’s assurance that the port expansion project includes some of “the strictest conditions in Australian history … to ensure that any impacts are avoided, mitigated or offset”, concerns about the environmental impacts persist.

Image courtesy of Gary Bell/Oceanwidelmages.com

Image courtesy of Gary Bell/Oceanwidelmages.com

The Great Barrier Reef is one of the world’s richest and most complex natural ecosystems, providing habitat for a multitude of marine species and playing a vital role in biodiversity conservation. Furthermore, recent findings indicate that coral reefs may help regulate regional climates. However, the Great Barrier Reef is increasingly threatened by both natural and human pressures, including increasing temperatures and severe weather occurrences, pollution, shipping, and tourism. In the past three decades alone, the reef cover has declined by over 50%. Beyond the Reef’s incredible environmental features, it has significant economic impacts – adding $5.68 billion to the Australian economy and creating 69,000 full-time jobs, mostly in tourism, from 2011-2012.

So what are the ecological impacts of dredging on coral reefs?
Coral materials and limestone tend to break up into extremely fine particles when dredged, creating “clouds” of fine suspended sediments that can remain in suspension and spread over large areas.  This sedimentation significantly reduces light penetration to corals and their symbiotic algae, which depend on photosynthesis for food production.  For his reason, it is critical to minimize the dredging of coral rock.

Recently, experts from PIANC (The World Association for Waterborne Transport Infrastructure) investigated whether coral reefs can be protected during dredging.  Their 2010 report found the main impacts of dredging resulted in a direct loss of coral reef and extreme stress caused by increased turbidity and sedimentation. The group developed a set of guidelines for the implementation of best practice methods in environmental assessment and environmental management for dredging and port construction activities around coral reefs. They hope to minimize the impacts of inevitable dredging by promoting sound planning, impact assessment, monitoring and management practices to reduce the adverse effects of dredging and port construction on the Reef environment.

Studies and the current debate surrounding the Great Barrier Reef highlight the delicate balance between economic expansion and valuable natural resources. In the past, expansion has come at the expense of natural resources. And, while this is a highly controversial issue with supporters on either side, we need to look beyond the environmental implications and ask what precedents dredging the Great Barrier Reef will set? Where does it end and how much dredging do we allow in the future? If we are willing to jeopardize one of the most complex ecosystems and natural wonders what will stop similar projects in the future?

References:

Deloitte Access Economics 2013, Economic contribution of the Great Barrier Reef, Great Barrier Reef Marine Park Authority, Townsville.
Milman, Oliver. Inquiry into Gladstone Dredging Won’t Stop Abbot Point Project, Regulator Says. TheGuardian.com. Guardian News and Media, 20 Jan. 2014.
Milman, Oliver. Greg Hunt Approves Dredging off Queensland to Create Huge Coalport. Theguardian.com. Guardian News and Media, 10 Dec. 2013
PIANC Dredging and Port Construction around Coral Reefs (2010). United Nations Environment Programme World Conservation Monitoring Centre, Jan. 2010.
White, Alexander. Has the Great Barrier Reef Just Been Approved for Destruction by the Australian Government? TheGuardian.com. Guardian News and Media, 18 Dec. 2013.
Zubrzycki, John. Australia Approves Coal Port near Great Barrier Reef. The Christian Science Monitor. The Christian Science Monitor, 15 Dec. 2013.

 

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