The Magazine of The Sierra Club
Researchers Deploy COTSbot to Protect Great Barrier Reef
A robotic submarine uses AI to seek and destroy a thorny menace
The Great Barrier Reef is facing many threats—most notably, the increase in ocean water temperature, which has been killing off vast swaths of coral. But another menace comes in the spiky form of the crown-of-thorns starfish, a predator that can consume up to 65 square feet of coral per year. This species is native to the Great Barrier Reef, but over the last 30 years, periodic booms in the starfish population have thrown off the ecosystem's balance of predators and prey. To combat this ravenous foe, researchers at Australia's Queensland University of Technology invented a robotic submarine called COTSbot, which cruises the reef and uses artificial intelligence to seek and destroy the crown-of-thorns.
The crown-of-thorns starfish wreaks havoc by attaching itself to corals, extruding its stomach to release a flood of digestive enzymes, then sucking up the liquefied coral tissue.
The sub's cameras scan the reef, and its computer vision software autonomously identifies targets. The researchers equipped COTSbot with a database of thousands of underwater images showing many starfish species. Through a type of AI called machine learning, the bot has become expert in recognizing crown-of-thorns starfish even when they're wrapped around coral or partially obscured.
When COTSbot spots a target, it goes into position over the starfish and unfolds its arm, which has a needle at the tip. The needle pierces the starfish and injects a lethal dose of bile salts, a chemical compound that human divers have been using to kill off the marauders in recent years. The sub can eradicate 200 starfish in an eight-hour mission.
This article appeared in the November/December 2017 edition with the headline "Reef Predator Patrol."
Infographic by Brown Bird Design
