The eruption of the Hunga Tonga-Hunga Haʻapai volcano in January not only shook Tonga, but also its marine ecosystem.
The ashes from the volcano brought nutrients to the sea surface — creating favorable conditions for phytoplankton growth.
The population of phytoplankton increased by 10 times in a couple of days.
Satellite imagery showed the phytoplankton growth was 40 times the size of Oʻahu.
Phytoplankton is responsible for photosynthesizing carbon dioxide and regulating the atmosphere. It also attracts bigger microorganisms and moves up the food chain to fish.
"This was really remarkable in our field in the sense that seeing this magnitude of change in such a short term is not something that we see often in the ocean," said Benedetto Barone, a research oceanographer with the University of Hawaiʻi at Mānoa.
The ocean surrounding Tonga usually has a low concentration of phytoplankton due to the ocean currents.
"This tenfold change in the concentration of phytoplankton, there are not other kinds of perturbation besides the strong volcanic eruption that can produce such an impact on a large region in such a short time," Barone told HPR.