The Hunga volcano eruption in January 2022 had a severe impact on marine ecosystems in Tonga, as revealed by a recent research expedition led by Roxanne Beinart, a marine microbial ecologist from the University of Rhode Island.
Beinart’s team was initially in the Lau Basin to study deep-sea hydrothermal vents but discovered the seafloor blanketed in volcanic ash. “It was like a snow-covered landscape,” Beinart described. The thick ash deposits, reaching up to 1.5 meters deep, decimated local marine life, particularly vulnerable species such as snails and mussels.
The ashfall from the eruption, one of the most powerful ever recorded, has drastically altered the ecosystem. Marine geoscientist Mike Clare noted the ash’s ability to travel over undulating terrain and reach the hydrothermal vents, highlighting the strength of the volcanic currents. “Despite this irregular seafloor relief, the flows have been able to overcome this distance,” Clare explained.
Comparisons with footage from a 2019 expedition showed stark contrasts. While some mobile species like lobsters and crabs remained, the populations of snails and mussels were severely affected. Beinart emphasised, “Those populations were decimated.”
The research team plans to return in 2026 to monitor recovery. “We’re focused on trying to understand the recovery of these systems and the dynamics of how they might cope,” Beinart said.
