Restoring our reefs and oceans

Supporting active reef and ocean restoration to help secure the future of the most ecologically diverse living structures on earth and the oceans on which we depend for survival. Meet RangerBot: a new undersea robot giving nature a helping hand during coral spawning on the Great Barrier Reef.

Eradicating destructive reef pests and growing healthy, new coral

The Great Barrier Reef is the largest living structure on earth – its size vital to its resilience. Extending more than 2,900km along the Queensland coast, the reef’s size also presents logistical and fiscal challenges for large-scale restoration and monitoring.

Crown-of-thorns starfish (COTS) outbreaks continue to have a detrimental impact on the reef, with these thorny starfish voracious predators responsible for an estimated 40 per cent of the reef’s total decline in coral cover.

In response to the urgent need to actively intervene to boost the reef’s capacity to recover, QUT roboticists developed the world’s first robot designed to monitor and control the crown-of-thorns starfish population on the Great Barrier Reef in 2015.

Originally known as ‘COTSbot’, this autonomous underwater robot has been proven to detect and kill crown-of-thorns starfish without damaging the reef. This class of robot is designed to operate without a tether and execute missions with minimal human interaction once deployed. The key features include real-time and on-board automated image-based detection of COTS, autonomous injection of bile salts into detected COTS, and autonomous navigation within shallow coral reefs.

In 2016 QUT partnered with the Great Barrier Reef Foundation to win the Google Impact Challenge to develop the COTSbot into the RangerBot AUV to be the ‘Swiss army knife’ of the seas.

In a world first in 2018, RangerBot capabilities were further expanded to include dispersal of microscopic baby corals (coral larvae) to help scientists working to repopulate parts of the Great Barrier Reef during the annual mass coral spawning event. This robot, affectionately termed ‘LarvalBot’, has been developed to support the regeneration of bleached and degraded reefs through distributing coral larvae – fertilised via innovative ‘coral IVF’ techniques. LarvalBot is able to distribute tiny ‘coral babies’ at optimal times which settle onto damaged reefs and grow to restore healthy coral populations. Most corals reproduce once a year by simultaneously releasing billions of coral eggs and sperm which then fertilise to form tiny larvae. Within a couple of days, the larvae are ready to grow and settle onto available reef substrate, but only a tiny fraction of the larvae grow into mature coral colonies. LarvalBot has the potential to support an exponential increase in the settlement and growth of new healthy coral.

World leading technology

The RangerBot platform now consists of both underwater and surface drones. Unlike commercial ROV’s which require tethers and human-in-the-loop operation, the RangerBots remove these limitations through advanced autonomy. Uniquely, RangerBots can be deployed independently or collaboratively, with sophisticated yet intuitive software, to achieve targeted, large-scale monitoring and interventions for marine conservation not available on any other solutions. These ‘Swiss army knife’ features have evolved to meet the needs of a range of ocean conservation tasks including high-resolution imagery (with 3D mapping), real-time invasive species surveillance, water quality monitoring and sampling, and coral reef restoration. These highly developed and adaptable capabilities mean the RangerBot platforms can be adopted for positive change at all levels of ocean conservation.

Proven capabilities

  • Coral larvae capture and delivery to damaged reefs
    • capable of delivering 3 million larvae in 3 hours
    • 100% success rate in delivering coral larvae to damaged reefs
  • 99.4% accuracy in detecting COTS
  • Marine pest control,
  • Underwater surveys and reef health monitoring
  • Water quality testing
  • Autonomous ‘swarming’ ability – robots controlled by one operator work autonomously and collaboratively to perform marine conservation tasks

What’s next?

QUT’s underwater robot RangerBot delivers coral babies. Image courtesty of Juergen Freund.

QUT’s goal is to commercially launch the RangerBot platforms as the go-to solution for ocean conservation monitoring and intervention in Oceania, and at least two other continents with over 200 units being delivered and used by 2025. Based on current performance, 200 units would be capable of imaging, monitoring and surveillance of 320 hectares of seafloor per day or spreading coral larvae over 25 hectares in a day. This international expansion will empower communities on the front line of ocean management with an affordable, versatile tool for monitoring and managing a wide range of marine issues. Subsidised (even free) systems for the most vulnerable and disadvantaged communities will be sought through tailored partnerships.



Image: Gold Coast Waterways Authority.