Barrier Reef threatened
Marine scientists have found that coral cover in the Great Barrier reef has halved in 27 years as a result of the combined effects of coral bleaching, damage caused by storms, and crown-of-thorns starfish.
Source: Lateline | Duration: 3min 45sec
EMMA ALBERICI, PRESENTER: The Great Barrier Reef has lost half its coral in the past 27 years; that's the finding of a new study from marine scientists.
The causes of the coral decline are cyclones, coral bleaching and the crown-of-thorns starfish.
John Stewart reports.
JOHN STEWART, REPORTER: It's the world's largest coral reef, stretching 3,000 kilometres along the Queensland coast. But according to marine scientists, it's in trouble.
JAMIE OLIVER, AIMS RESEARCH SCIENTIST: The study has found that over the last 27 years there has been a nearly 50 per cent decline in coral cover, from approximately 28 per cent in 1985 to down to 14 per cent in the present day, 2012.
That's a very substantial, alarming and unsustainable decline of coral on the Great Barrier Reef.
JOHN STEWART: The study found three main causes of coral decline. Storm damage has been linked to 48 per cent of coral loss. The crown-of-thorns star fish, 42 per cent of coral loss, and coral bleaching, 10 per cent.
JOHN STEWART: The decline in coral cover varies in different parts of the reef. North of Cooktown the reef is far less affected, but further south the impact is more serious.
JOHN GUNN, INSTITUTE OF MARINE SCIENCE: In the south by contrast, they've had the impacts of crown-of-thorns and in particular over the last decade a series of very, very severe storms that have had a devastating effect, and so the decline in the south of the Great Barrier Reef, south of Proserpine, has been much, much more profound than in the north.
JOHN STEWART: The explosion of crown-of-thorns starfish on the reef has been closely linked to fertiliser run-off causing algal bloom, which then feeds the marine pest. Environment groups say the Federal Government needs to step in to help farmers reduce runoff into rivers.
NICK HEATH, WWF: We're calling on the Federal Government to inject $500 million or more to help farmers cut their rates of fertiliser over the next few years.
JOHN STEWART: Coral bleaching and an increasing trend of tropical cyclones and storms have been linked to global warming.
JOHN GUNN: We already know from major bleaching events from 1998 and 2002 on the Great Barrier Reef, and many other bleaching events around the world, that corals just cannot tolerate greatly increased temperatures. And so if we see the two degrees that is predicted, we know that we will have a massively increased rate of bleaching on the Great Barrier Reef.
JOHN STEWART: The Great Barrier Reef brings an estimated $5 billion a year to the Australian economy. The Queensland Tourism Council says the survival of the reef is crucial for the state.
DAVIEL GSCHWIND, QLD TOURISM INDUSTRY COUNCIL: We have to continue in vigorously attacking the crown-of-thorns where we find them and through the management programs that are in place, but that's only a drop in the ocean. We have to address the bigger issues, the long-term implications, the long-term water quality issues - that's where we have to focus our attention. That's very costly, but we deserve as a community, we deserve that investment, it's in our interest.
JOHN STEWART: The report warns that at the present rate of decline, the coral cover could halve again within 10 years. But scientists are still optimistic that the reef can be saved.
JOHN GUNN: What we're seeing in the Great Barrier Reef - a very, very well-managed system - is that there are some things we can't control that I think we have a Government that has very much put its money where its mouth is. The farmers of Queensland are doing the same. We think we can save the reef for as long as it takes to try and overcome the impasse around carbon dioxide emissions.