Crown-of-thorns starfish control

Expanding efforts to control crown-of-thorns starfish and reduce coral mortality from outbreaks to protect high ecological and economic value coral reefs.

Scuba diver conducting COTS research

#Crown-of-thorns starfish outbreaks threaten our Reef and the thousands of species of marine life that call it home.

​Budget: $57.8 million​.

The Reef is experiencing its fourth major outbreak since the 1960s, and the window of opportunity to control crown-of-thorns starfish (COTS) is now.

By bringing together Reef managers, Traditional Owners, scientific experts and industry leaders, the Reef Trust Partnership's COTS control component is ensuring the most effective and efficient decisions are being made when controlling the current COTS outbreak, and finding innovative and scalable ways to address this key threat to the Reef into the future.

#End of Partnership Outcomes

The Partnership’s COTS control component will result in:


Reduced coral mortality from COTS outbreaks at high-value reefs

New methods identified to manage COTS at scale

More partners involved in COTS management (including Traditional Owners)

A strategy available for long-term funding

#Progress Dashboard

Transparency and accountability are key guiding principles for the Foundation in delivering the Reef Trust Partnership.

A series of interactive dashboards has been developed as part of our Monitoring and Evaluation Plan. The dashboards are updated every six months to demonstrate progress towards meeting End-of-Partnership Outcomes. The following dashboard provides a snapshot of key progress areas that deliver the COTS control component’s end-of-Partnership outcomes.

Find out more about the RTP progress dashboards in these Frequently Asked Questions.

#Partnership Activities

Our five-year plan for the COTS control component includes the following eight Partnership Activities:

COTS control

Budget: $41.5 million

Controlling crown-of-thorns starfish is the most scalable and practical tool we currently have to protect our Reef's corals, and the Partnership’s COTS control program is by far the largest-scale intervention program happening right now on the Reef.

This funding will support continued COTS control at a level consistent with scientific advice and intensity of the current outbreak.

COTS control innovation: feasibility study

Budget: $1.5 million

This funding will deliver a collaborative feasibility study involving key scientific agencies to systematically investigate the potential of new COTS control options.

Recommendations from this study will guide the subsequent COTS control innovation: implementation activity, with the goal to enhance our ability to predict and detect outbreaks and more effectively control their spread and impact.

COTS control innovation: research and development

Budget: $8.3 million

Targeted investment in transformational innovations, based on outcomes of the COTS control innovation feasibility study, can provide a pathway towards a step change in COTS control. This funding will enable research and development, testing and implementation of new methods including early warning systems, early intervention options, alternative control technologies, and improved prediction and decision making.

Independent scientific reviews

Budget: $250,000

The need for an independent review of COTS control program effectiveness was highlighted during Partnership consultations (including with the Reef 2050 Independent Expert Panel). The COTS control program is continuously evolving, and its effectiveness will benefit from regular independent reviews (2020 and 2024).

COTS forums

Budget: $200,000

Regular forums dedicated to COTS research and management are planned for 2021 and 2024, focused on identifying innovation priorities and to address the long-term challenge of COTS control. These forums will enable cross-sector dialogue and support long-term planning of innovation in COTS management.

Long-term funding strategy

Budget: $150,000

This funding will provide a comprehensive business case and real options to support planning and policy development for long-term funding of COTS management.

Community-driven COTS control

Budget: $100,000

The role of community and citizen science to engage more widely in COTS control has been identified as an opportunity to expand partner delivery capacity.

This funding will identify opportunities to support community and citizen science
participation in COTS control and implement pilot programs.

Traditional Owner-led COTS control

Budget: $5.8 million

This funding will identify and deliver training to upskill Traditional Owners and provide funding to enable COTS control activities. It will also support business-ready Traditional Owner groups to transition to manual COTS control activities.


Under the overarching partnership activities sit a suite of projects. Projects include both our impact-driven, largely on-ground actions being delivered by our partners, as well as a small number of enabling and supporting activities that together, will achieve the End of Partnership Outcomes. Below is a summary of the on-ground projects funded so far under the COTS control component.

COTS Control Program

A partnership with the Great Barrier Reef Marine Park Authority and Reef and Rainforest Research Centre to protect coral from crown-of-thorns starfish.

The largest scale on-ground intervention program on the GBR. This program reduces coral loss from COTS outbreaks at high-value reefs. Every day, 5 vessels and 100+ divers are out on the Reef to survey and remove Crown-of-thorns Starfish.

See the above dashboard for program highlights. For detailed information on project activities and outbreak status, visit the GBRMPA's quarterly COTS dashboard.

2021 International COTS Control Forum

29-31 March 2021 in Cairns

The International Crown-of-Thorns Starfish Control Forum is a collaborative effort between the Reef Trust Partnership and the Reef and Rainforest Research Centre (RRRC). The forum was the first in the history of COTS management on the GBR to connect a diverse group of stakeholders, promoting cross-sector dialogue across domestic and international researchers, reef managers, control program vessel crews, tourism industry representatives, and Reef Traditional Owners. Over the two-day event, thirty-seven presentations were delivered to share scientific, cultural and management knowledge for COTS Integrated Pest Management (IPM) control and discuss opportunities for future innovation in this area. Click on the link below to watch the presentations.

Following the success of the inaugural International Crown-of-Thorns Starfish Control Forum, a second forum will be held in 2024.



A targeted research program aimed at boosting capacity to predict, detect and respond to COTS outbreaks at scale across the Great Barrier Reef.