Volcanic eruption in Tonga could result in acid rain

Scientists reviewing satellite photos have warned that the massive volcanic eruption in the Pacific island nation of Tonga might cause long-term damage to coral reefs, erode coastlines, and disrupt fisheries. Sulphur dioxide and nitrogen oxide have been released by Hunga Tonga-Hunga Ha'apai, an undersea volcano that erupted on Saturday, causing tsunami warnings across the Pacific. Sulphur dioxide and nitrogen oxide are two gases that produce acid rain when they interact with water and oxygen in the atmosphere.

"Acid rain is expected to continue over Tonga for some time," said Shane Cronin, a volcanologist at the University of Auckland, to Reuters.

Acid rain damages crops all throughout the world, including Tongan mainstays like taro, corn, bananas, and garden vegetables. "Food security could be jeopardised depending on how long the eruptions occur," Cronin added.

According to satellite photos, the plume is moving west, which means Tonga may be spared some acid rain at the price of Fiji.

The UN humanitarian affairs office monitors Fiji's air quality, which has encouraged residents to cover their household water tanks and stay indoors if it rains.

Coral reefs, which were already threatened before the eruption, could be harmed by falling ash.

"Vast portions of the reefs in the immediate impact region at Hunga Tonga are presumably buried and suffocated by massive concentrations of volcanic ash," said Tom Schils, a marine biologist at the University of Guam.

According to Schils, eruptions like the one on Saturday release more iron into the sea, which can encourage the growth of blue-green algae and sponges, further degrading reefs.

Although scientists have yet to investigate on the ground, satellite imagery reveals a blanket of ash covering the land. According to the Tonga Geological Services, ash can be damaging to marine life in the ocean, and fisherman should "think fish in these seas are poisoned or poisonous" because neighbouring saltwater was contaminated by toxic volcanic emission.

Tonga is made up of 170 islands, 36 of which are inhabited, and has a population of roughly 100,000 people.

Scientists have cautioned that fish may kill or migrate as a result of the eruption, as most Tongans rely on the ocean for their food and livelihood.

"It will be a long time before the same or new fishing grounds are rebuilt," said Marco Brenna, a geologist at New Zealand's University of Otago.