(Reuters) – Tongas large underwater volcanic eruption could cause long-lasting damage coral reefs, erode coastlines, and disrupt fisheries. Scientists studying satellite images and looking back to the past to project future conditions in remote regions are predicting that Tongas will be a major disaster.
Since the eruption, the volcano has been emitting sulfur dioxide and nitrogen oxide. These gases are acid rain-causing compounds that react with water and oxygen in their atmosphere.
According to Shane Cronin, University of Auckland volcanologist and author of Tongas tropical climate, acid rain will likely be around Tonga for some time.
Acid rain can cause widespread crop damage and could lead to the destruction of Tongan staples such as taro, corn and bananas, as well as garden vegetables and other vegetable crops. Cronin stated that food security could be compromised depending on how long the eruptions continue.
Satellite imagery shows that the plume is spreading westward. This means that Tonga may be spared some of the acid rain, but Fiji could be in its path.
The U.N. humanitarian Affairs office stated Monday that Fiji was monitoring the air quality and advised residents to cover their tanks and stay indoors if it rains.
Tongas exclusive economic area of almost 700,000 marine kilometres (270.271 square miles), is 1,000 times bigger than its land surface. Tongans depend on the ocean for their food and livelihood.
Marco Brenna, a geologist at Otago University in New Zealand, said that scientists have yet to investigate the ground. However, the few photos that are available seem like it shows a blanket… of Ash on the Land.
This ash can pose a danger to marine life in the sea. Tonga Geological Services warned weeks before Saturday’s eruption that seawater nearby was contaminated by toxic volcanic discharge. Fishermen should assume that fish in these waters is poisonous or poisonous.
Inevitably, the situation got worse due to the eruption. The volcano’s ash-filled water will make it difficult for fish to eat and will wipe out their spawning grounds. Scientists predict that some fish will die and that survivors will have to migrate. Fishing vessels could face new challenges if the seafloor structure changes.
Brenna stated that it will take a while before the old or new fishing grounds are restored.
Falling ash can also cause coral reefs to be destroyed. Tonga’s mainstay tourism industry brought in as much as $5 million annually prior to the coronavirus pandemic.
Tongas Reefs were already at risk from disease outbreaks and climate change, including coral bleaching and stronger cyclones, even before the eruption.
Tom Schils, who is a University of Guam marine biologist and has studied volcanic eruptions and corals from the Northern Mariana Islands, stated that large areas of reefs in Hunga Tonga’s immediate impact area are likely to be buried or smothered now by large volcanic ash deposits.
Additionally, such eruptions can release more iron into the seawater, which can encourage the growth and development of blue-green algae as well as sponges that further reduce reefs.
Brian Zgliczynski from the Scripps Institution of Oceanography, a coral reef expert, said that reefs may need to be rebuilt. This can take years. He stated that species more tolerant to low water quality will arrive first while hard corals and fish will take longer for their return.
Tonga’s ability and ability to deal with rising waters, storm surges, and the loss of corals reefs could also be affected. This is a concern in Tonga where climate change is driving sea level rise by 6 millimeters (0.2 inch) per year, twice the global average.
In a 2015 report https://www.researchgate.net/profile/Leanne-Fernandes/publication/317341776_National_marine_ecosystem_service_valuation_summary_Tonga/links/5bbe5828299bf1010178adac/National-marine-ecosystem-service-valuation-summary-Tonga.pdf, Tonga valued its natural storm buffers including coral reefs as well as coastal seagrasses and mangroves at some $11 million annually.
A Tongan sea-level gauge recorded the tsunami wave of 1.19m (nearly 4 feet) in the latest eruption. It then stopped reporting. Tsunamis can cause coastal erosion. Videos showed damage to man-made seawalls before the internet was down.
Cronin stated that tsunami waves could cause damage to coastal defences and reclaimed ground, making islands more vulnerable.
(Reporting by Gloria Dickie. Editing by Katy Daigle. Howard Goller.
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