Matching the Crown-of-Thorns Starfish Integrated Pest Management to the scale of the new Control Program

Dave Westcott
Led by: Dr David Westcott, CSIRO


Project Summary

The CoTS IPM program is designing an ecologically informed control program that integrates knowledge of the spatial and temporal dynamics of CoTS outbreaks and the operations of on-water control to provide i) the most efficient strategies for investing management effort at all scales of management, ii) an operational framework for the control program, and, iii) to identify and fill key research gaps. This project will support the expansion of the IPM’s tools to match the expansion of the control program, finalize scenario testing to assess appropriate control objectives, and, assess the social benefits of the CoTS training program.


Project Publications
Technical Report
Technical Report
Technical Report
Technical Report





Project Description

1. Ensuring the Local Area Decision Support Tools Meet the New Management Need

1.1 Leveraging new data sources: The adoption of the IPM approach by GBRMPA and the expansion of the CoTS program means that an expanded range and quality of data sources are or will be available meaning that opportunities to utilize this data to improve and broaden the DSTs is steadily increasing. This component of the proposal would further develop and refine the ecological-statistical analyses underpinning the Local DST, optimizing the control process and maximizing the impact of control in protecting coral.

1.2 Expand the DSTs to meet the new scale of the management response: The move to an expanded Control Program, with a fleet of vessels and multiple providers with differing capabilities and experience operating across multiple regions means that the Local DST must provide more complex guidance in on-water decision making and do so in a more ecologically and operationally complex context. These changes will, for example, spread decisions and control activities across the fleet, amortizing the cost of management actions and changing the relative nett benefit of different strategies. These decisions will be optimized through analysis and modelling to identify the best local area tactics for the expanded fleet would be the focus of this work and would ensure the NESP investment is servicing the control program’s needs.

2. Integrating the Local DST (NESP 2) with Regional DST (NESP 3)
Under the original program, the process of identifying where in a region to operate could be reasonably separated from decisions about how to operate in that region because control operated to protect assets at a sub-reef scale and vessels operated in different regions. In the expanded program resources are more favourably scaled to the problem, providing the opportunity to achieve meaningful ecological outcomes at regional and potentially GBR scales. This, however, requires the analytical integration of the Local DST, the Regional DST, and ultimately the surveillance program (NESP 4). Key components would include:

2.1 Integration of local scale decision making into regional scale models: This would involve incorporating the detailed understanding of short-term, local-scale decisions being made by on-water Control Program staff provided by the Local DST into the regional scale models underpinning the Regional DST. This would extend work already underway in NESP3.

2.2 Integrating data from the expanded Control Program into the regional scale decision support tool: This work will incorporate the greater volume of detailed cull and surveillance data being collected and optimized by the data collation and Local DST in near real-time into the Regional DST. The key ecological processes underpinning the current Regional DST are the dispersal networks of CoTS and coral larvae and the known or estimated distribution of CoTS across the region. This information can update reef prioritization just once a year. The expanded CoTS Control Program provides an opportunity to also include cull and surveillance data across key regions from the on-water programs. Combining this regularly updated, region-wide data with the currently used ecological process information to dynamically update local scale decisions would greatly improve the performance at regional and GBR scale outcomes.

2.3 Linking to Project 4.5: NESP TWQ Hub Project 4.5 will produce a guidance tool to assist in identifying the reefs where investment will provide the greatest ecological and socio-economic benefits. This project will work alongside project 4.5 to develop their tool and to identify how the products of project 4.5 can guide reef selection in the CoTS Local Area and Regional DSTs.

2.4 Bringing it together: ensuring DST apps are fit and functional in use: A focus of the development of the final DSTs must include the analysis and refinement of how they operate in the hands of decision makers and on-water operators and ensuring performance is robust and reliable. This work would ensure that this is the case.

3. Advanced scenario testing for the expanded Control Program

In theory, the same models that underpin the Local and Regional DSTs can be used to assess alternative objectives and strategies at the GBR-scale. In reality, however, informing control and running scenarios to assess alternative objectives requires different formulations of the models. Good progress is being made in the NESP 3 Regional Scale DST project towards developing the models required for scenario testing (based on the ReefMod and CoCoNet models) but it is rigorous scenario testing will likely be beyond the resources of that project. These models will provide, for the first time, a coherent overview of how CoTS control actions scale across the entirety of the GBR and allow identification of the mix of current and future control technologies that are likely to have the most potential to reduce the impact of CoTS populations in future, appropriate strategies for their implementation, and guidance for future investment decisions.

4. Blueprint for a long-term CoTS Control Strategy

The combined outputs from the NESP CoTS IPM program will provide the tools, experience and analyses to provide the underpinning strategy and framework for the implementation of a long-term CoTS control program. This component of the project would synthesis the different aspects of the work to provide this.

5. An assessment of the CoTS Training Program

The CoTS control program has played an important role in training and launching young people into careers in management and tourism on the GBR as well as serving to transition under and unemployed youth into the workforce more generally, with a particular focus on Indigenous youth. A formal assessment of this aspect of the program, however, has not been done and such a study would be instructive in considering the role of the training program in the expanded CoTS Control Program and in other reef program. This project would explore and document the benefits the CoTS control program provides through its youth training. The work would focus on benefits at two levels: i) the perception of benefits of individuals that have participated in the program, and, ii) performance at the program level.

The individual level study would be based on interviews with past and current trainees and would focus on i) their perceptions of the value of the program, ii) its impact on their careers, iii) their sense of social responsibility, iv) impact on their personal association with and responsibility for the reef.

Where possible direct participation of Traditional Owners in the product will be sought.

The program level study would consider factors including: i) Qualifications gained, ii) employment post-program, iii) social return on investment ($ generated/taxpayed $ saved, by the program), iv) social and Indigenous benefits of the CoTS control program, v) an evaluation of the program as a model for other reef traineeship/employment programs, vi) contribution towards improving progress towards the Reef 2050 Indigenous Strategy goals.


NESP 2017 Research Priority Alignment

NESP Priority Theme 1.1 – Further development of a systematic approach to crown of thorns control.


Project Keywords

Crown-of-thorns starfish; COTS; Integrated pest management; Pest species; Decision support tool.


Project Funding

This project is jointly funded through CSIRO, JCU, UQ and the Australian Government’s National Environmental Science Program.