Underwater Volcanic Eruption Caused Havoc in The Deep Sea — Severely Affecting Marine Life

In 2022, an ocean eruption apparently left several underwater beings grasping for breath. This eruption occurred due to the Hunga volcano, which released a 37-mile plume into the atmosphere, as reported by Phys. Researchers believe that deep-sea life was affected drastically, as the eruption caused extreme movement of underwater sediment. The exact consequences had not been analyzed in detail before. To do so, experts collected seafloor ash produced by the Hunga volcanic event, which gave them a glimpse of the state of affairs in the deep-sea environment. Findings regarding this investigation were published in the journal Geochemistry, Geophysics, Geosystems.

Discovery of Ash Sediment

The ash sediment was gathered by Marcus Chaknova, then a marine biology and geology major at the University of Oregon College of Arts and Sciences, four months after the Hunga Volcanic event. He was ecstatic to get his hands on the sample, as it could reveal little-known details about the havoc the volcano caused in the waters. Chaknova collaborated with Earth Sciences Professor Thomas Giachetti and 16 other researchers to examine the samples to understand the geological and biological consequences of movement in volcanic sediment. These consequences could also help determine the effect this transportation can facilitate during manual activities, such as deep-sea mining. 

Geological Consequences of the Eruption

For researchers, the first step was to determine whether the ash sediment belonged to Hunga volcano eruption or not, according to Earth. For this, Chaknova matched the samples with the ash found near the volcanic mountain. The grains were varying; some were jagged and sharp, while others were rounded and smooth. He determined that the samples in his custody had originated from the volcano’s caldera walls and were moved by underwater flows. The analysis revealed that the flows were so powerful that the ash managed to even break submarine cables and make small canyons into the seafloor. Based on the power cut induced by the damage to cables, the experts were also able to calculate the speed of the ash surge. 

Biological Consequences of the Eruption

According to the World Wide Fund for Nature, 90% of marine life uses the seafloor as habitat. Most of this population got buried under thick sediment, due to the ash surge. Creatures like worms and anemones can sustain themselves even after brief burials, but the ash surge proved to be too powerful even for them. Several deep-sea species were clogged, as they started feeding on sediments in the surge. These species use suspension feeding for their food requirements. In this process, the creatures capture tiny particles of food from water and filter them through their gills. However, in this scenario, they were just capturing sediments. “That’s going to clog their gills, it’s going to clog their intestines, and that’s going to have a dramatic effect on their ability to create energy,” Chaknova explained.

The ash also reached Tonga’s coral reefs, and initially facilitated a plankton bloom, which soon came under control. As the ash settled, it began hampering the corals, which further disrupted all the creatures present in food chains related to this invertebrate. It caused a decline in fish population, which in turn affected Tonga residents who depend on them for their livelihood. These results are a warning siren for deep-sea mining that could potentially flourish in the area in the coming years, due to its deposits of minerals. The mining could cause a similar movement of sediments and create havoc on an even larger scale.