Killer robot electrocutes lionfish in Atlantic to save ecosystem

The lionfish, native to the Indian Ocean and the Pacific, has been introduced to the Atlantic by humans. Spectacular in fish tanks and aquariums, the venomous creature with its characteristic red and white stripes and spikes has no natural predator in the Atlantic to help keep the population in check. As a result, millions of them now roam the Caribbean, preying on corals and juvenile native fish, which don’t recognise them as a threat.

"Lionfish populations are increasing in non-native waters at a disproportionate rate,” said Lucy Woodall, from the University of Oxford, who coordinates activities of the ocean research charity Nekton, which is now testing the lionfish-killing robot in the Atlantic.

“Ecosystems suffer as lionfish devour the small fish leaving nothing for the other marine animals to feed on. They also prey on herbivores who feed on reef algae, ensuring their growth is kept in check. Without this crucial link, the algae growth smothers the coral, blocking sunlight, which eventually kills the coral reef." 

Sexually mature in just 12 months, a female lionfish produces some 30,000 eggs every four to five days. An adult lionfish needs to consume about half its body weight per day. The invasive species is also being increasingly spotted in the Mediterranean.

The lionfish killer robot, developed by US non-profit company Robots in Service of the Environment (RISE), is operated via a videolink. When the operator spots the voracious creature, he or she navigates the robot towards it. The robot embraces the lionfish with its metallic paddles and delivers a fatal electric shock. The carcasses can subsequently be collected and either disposed of or sold at market. Lionfish can be eaten and is described as being delicious; the venom from its spiky ray fins does not contaminate the edible tissue if handled correctly.

"Currently there isn't an effective way to conduct mass culling,” said Chris Flook from the Department of Environment and Natural Resources of the Government of Bermuda, which is struggling with an out-of-control spread of lionfish. “We have spear fishers with special permits that catch lionfish on shallow reefs but lionfish survive at depths beyond the reach of recreational divers."

According to the researchers, the killing robot takes advantage of the lionfish’s gullibility.

"Lionfish are not naturally afraid of anything so they swam in and around it,” RISE's executive director John Rizzi described the first tests. “Once we have completed a number of similar trials over the next nine months, we intend to build our first commercially viable ROVs."

The project is part of the XL Catlin Deep Ocean Survey, a multidisciplinary research programme assessing the health and resilience of deep-ocean ecosystems.

The RISE team is not the first to have introduced the idea of using robots to control overgrown populations of ecosystem-disrupting species. Last year, an Australian team introduced a robot that injects starfish with bile salts to kill them. Starfish, also known as sea star, decimates coral populations in the Australian waters.