There is emerging evidence that poor water quality resulting from floods and extreme weather events in the summers of 2009 to 2011 have created conditions for crown-of-thorns starfish numbers to increase at some locations on the Great Barrier Reef.

To support the resilience and diversity of the Reef, short and long-term strategies that target the immediate problem and the underlying causes are underway.

What is the short-term strategy?

The Great Barrier Reef Marine Park Authority (GBRMPA) has a general approach of not interfering with natural processes. In the case of crown-of-thorns starfish, outbreaks are known to occur naturally. With scientific evidence now indicating that poor water quality leads to an increase in their numbers and outbreaks increasing beyond what are considered natural, control activities may be implemented in some locations.

Crown-of-thorns starfish outbreaks are a matter of serious concern for the overall health of the Reef and its capacity to recover from disturbances, particularly with increased pressures caused by declining water quality and climate change. Outbreaks are also a matter of concern for the Reef tourism industry. When an outbreak occurs, a site valuable to tourism can be so severely degraded that it loses much of its aesthetic value, negatively affecting customer satisfaction.

In the short-term, GBRMPA is working closely with the Association of Marine Park Tourism Operators to develop a crown-of-thorns starfish control strategy to assist the tourism industry to protect coral at sites of high tourism value. This will also investigate broader control measures.

Funding of $1.43 million under the Australian Government's Caring for our Country program will assist the tourism industry in control efforts. This will be matched by a significant contribution from the industry itself, through staff time and vessels.

What is the long-term strategy?

GBRMPA is focused on the long-term protection of the Reef through a range of programs. Initiatives such as Reef Rescue and the Reef Water Quality Protection Plan, are aimed at improving water quality and are expected to reduce the long-term risk to the Reef ecosystem from crown-of-thorns starfish. There are early indications that these programs are successfully improving water quality.

The Great Barrier Reef Marine Park Zoning Plan 2003 provides for ecologically sustainable use of the Marine Park and helps to manage and protect its values. Zoning is a key strategy for improving the Great Barrier Reef's health and resilience.

How are crown-of-thorns starfish monitored on the Reef?

The prevalence of crown-of-thorns starfish is monitored through various programs such as the Australian Institute of Marine Science long-term monitoring program and our Eye on the Reef program.

What else can we do?

Crown-of-thorns starfish outbreaks have been identified as an emerging priority by the National Environment Research Program, which is now funding a range of activities including scientific research and expert workshops. Scientists at the Australian Institute of Marine Science and James Cook University are investigating control measures and looking further into the links between water quality, nutrient levels and crown-of-thorns starfish outbreaks.