Carleton University study shows global warming is affecting lionfish appetite

A new study from Carleton University shows that invasive lionfish, which have a digestive system that prefers heat, eat more and perform better as the ocean warms from climate change.

According to the university, Clay Steell and Steven Cooke’s, Fish Ecology and Conservation Physiology Lab is the first to show this and explore that topic.

Lionfish have destroyed marine ecosystems in the western Atlantic Ocean and eastern Mediterranean Sea by preying on vulnerable fish and crustaceans. The study found that lionfish put more energy into digestion than they do with other activities like swimming when compared to other fish. This may explain why they are known as underwater invaders.

“Past research has shown that lionfish move into colder waters and eat different prey as the ocean warms,” says Steell, adding that, “However, this is the first evidence that a warmer ocean can give them more energy to grow and reproduce. This is because their digestion used 30 per cent less energy at 32°C than at 26°C.”

This energy saving fact means lionfish can eat larger and even more frequent meals in warmer waters, which could increase their impact on marine ecosystems as sea temperatures rise due to climate change. These findings could help improve the accuracy of predictions about the impact of climate change on lionfish invasion, and indicates that current predictions underestimates the species’ impact.

“This important study not only warns us that the climate crisis could amplify the lionfish, but it also shows how understanding an invasive species’ physiology is key to understanding its impact on the places it invades,” says Steell.

The study, which is called ‘An Appetite for Invasion: Digestive Physiology, Thermal Performance and Food Intake in Lionfish’, is published in the Journal of Experimental Biology. To read it, visit Experimental Biology’s website.