The Tonga eruption caused an immediate explosion of life

Oct. 13 () –

Tonga’s underwater volcanic eruption recorded in January 2022, the largest this century, caused a spectacular bloom of microscopic marine life in a matter of 48 hours.

A team led by the School of Earth and Ocean Sciences and Technologies (SOEST) at the University of Hawaii at Manoa analyzed satellite images of various types (true color, emission of red and infrared radiation, and reflection of light from the surface of the sea) and determined that the deposition of volcanic ash it was probably the most important source of nutrients responsible for the growth of phytoplankton.

Phytoplankton are the tiny photosynthetic organisms that produce oxygen and serve as the base of the marine food chain. The growth of these microbes is often limited by low concentrations of dissolved nutrients at the ocean surface, but phytoplankton can increase rapidly when nutrients are available.

“Although the Hunga Tonga-Hunga Ha’apai eruption was underwater, a large column of ash reached a height of tens of kilometers in the atmosphere,” he said. it’s a statement Benedetto Barone, lead author of the study and a research oceanographer at the Center for Microbial Oceanography: Research and Education (C-MORE) at SOEST. “The ash fallout provided nutrients that stimulated phytoplankton growth, which reached concentrations far beyond the typical values ​​observed in the region.”

“We were impressed to see the large region with high concentrations of chlorophyll in such a short time after the eruption,” said Dave Karl, co-author of the study and director of C-MORE. “This shows how quickly the ecosystem can respond to nutrient fertilization.”

“A casual observer might see seemingly very different parts of the environment, in this case a volcano producing a large eruption and a major change in the ecology of nearby oceans,” said study co-author Ken Rubin, a volcanologist at SOEST. Department of Earth Sciences. “However, our observations illustrate the extensive interconnectedness and interdependence of different aspects of the environment, such once even indicating an underappreciated link between volcanism and shallow marine ecosystems globally.”

Phytoplankton extract carbon dioxide from the atmosphere, which is responsible for warming most regions of our planet. The eruption was a natural fertilization event that revealed the ability of these microscopic power plants to respond rapidly, when the right conditions exist.

“The dynamics of this event can help us predict the behavior of pelagic environments, when nutrients are added to nutrient-depleted regions of the oceanBarone said. “This knowledge may prove useful in discussing the impacts of carbon dioxide removal technologies based on ocean fertilization.”