Few people have seen the entire reef – it’s 3,000km long! Each part of the reef is unique, but those who have visited even one corner of this amazing underwater world talk in wonder of the exquisite, vibrant colours and shapes of diverse marine life. Diving the reef is almost like stepping into a parallel universe, experiencing a vision that inspires awe and respect for nature. I have a personal fondness for the reef, having worked up and down its length in my early 20′s, mapping the reef for the Australian bid for UNESCO World Heritage status, given in 1981.
At least, the reef used to be amazing, but the report card released in July 2013 has now downgraded the health of the Great Barrier Reef to “poor”. 72% of the reef’s hard coral has died since the 1960′s, leading UNESCO to question government protection and consider revoking its World Heritage status. The poor health of the reef, and proposed dredging for a new coal handling port has led Greenpeace to embark on a campaign to motivate state and federal governments to do more for its protection.
We know that as the oceans grow more acidic this weakens calcium formation of shells and coral. Also, much has been said on the outbreaks of crown-of-thorns starfish – these voracious creatures eat live coral, leaving behind white, dead coral, that soon turns green as algae make it their new home. But the real reasons for the degradation of this amazing reef (including the reason for outbreaks of starfish numbers) have now been well studied, and found not to be climate change, but pollution, mainly from the Burdekin and Fitzroy rivers, the largest rivers flowing onto the reef. What’s killing the reef is (in order of importance):
- Fine silt (the major coral killer), over 75% of which comes from grazing lands
- Nitrogen pollution, mostly particulate, from sediment erosion of grazing lands
- Phosphorous pollution, mostly particulate, from sediment erosion of grazing lands
Nitrogen and phosphorous nutrient increases are the major cause of crown-of-thorns starfish outbreaks. Minor sources of pollution were dissolved nitrogen and phosphorous from sugarcane production, as well as herbicides and pesticides, also from farming.
So there we have it – what’s killing the Great Barrier Reef is cattle.
State and federal governments responsible for the reef have been roundly criticised, but beef production is a fairly large domestic and export industry, and although detailed plans have been drawn up to improve pollution levels, only 17% of beef graziers complied with the plans, since compliance is voluntary.
But that’s not the end of the story. A recent report by The Economics of Ecosystems and Biodiversity (TEEB) found that the external (and therefore unpaid) natural capital costs of beef production on land use, water consumption, air, land and water pollution, waste and greenhouse gas emissions from cattle ranching and farming globally was 710% of revenue. In the case of Australia and New Zealand (analysed together), they found that the unpaid external cost of cattle ranching and farming was US$17.3 billion, compared to a revenue of US$3.4 billion per year.
This means that if the true cost to the natural environment was included, meat prices would rise by 500%. Most of this beef is bos indicus (Brahman cross) cattle grazed on low productivity rangelands, and is destined for export markets as lower value ‘industrial’ beef (ie hamburger beef). Therefore, a price signal of this order would almost guarantee the end of the industry, and the end of the largest source of degradation of the Great Barrier Reef.