Scientists say India's 'Deep Sea Mission' on track; hydrothermal vent discovery just the beginning

New Delhi: India's Deep Sea Mission is on the right track, and the discovery of an active hydrothermal vent 4,500 metres below the surface of the Indian Ocean this month will boost scientists' confidence and provide valuable experience for further exploration, the country's top scientists have said.

In an interview with PTI, Thamban Meloth, Director of the National Centre for Polar and Ocean Research (NCPOR), said this is just the beginning.

In a groundbreaking achievement, a team of Indian scientists from the National Institute of Ocean Technology (NIOT) and the NCPOR captured the first image of an active hydrothermal vent located 4,500 metres below the surface of the Indian Ocean around a week ago.

This is a major milestone in India's ambitious Rs 4,000-crore Deep Ocean Mission, aimed at exploring uncharted depths of the ocean to find new minerals and life forms and improve understanding of the ocean's role in climate change.

"Seeing is believing," Meloth said.

"While we had already identified proof of both active and inactive hydrothermal vents (in the Central and Southwest Indian Ridges in the Southern Indian Ocean), we wanted to get visual images. That's what we achieved this time," he said.

According to Meloth, the discovery validates the investment in the blue economy and boosts scientists' confidence to continue exploring. It will play a crucial role in building expertise for future expeditions, he said.

"While we are excited about this success, there is much more of the Indian Ocean to explore. Sustained support is needed for further studies. We are building a new ship for such surveys, which will be ready in three years as part of the Deep Ocean Mission," the NCPOR director said.

Hydrothermal vents are like hot springs on the ocean floor. They form along mid-ocean ridges where tectonic plates move apart. The magma from the Earth's mantle rises to fill the gap and cools to form new crust and volcanic mountain chains.

When seawater seeps into the cracks in the crust, it gets heated by this magma and shoots back out, carrying dissolved minerals. As the hot water meets the cold seawater, these minerals solidify, creating chimney-like structures around the vents.

The first hydrothermal vent was discovered in 1977 on the Galapagos Rift in the eastern Pacific Ocean. Since then, scientists have discovered hundreds of hydrothermal vents across the world's oceans, particularly along mid-ocean ridges, back-arc basins, and other tectonically active regions.

Meloth said hydrothermal vents are important for two reasons.

First, they produce valuable minerals like nickel, cobalt, and manganese, which are essential for modern technologies and clean energy solutions and second, they support unique life forms that thrive without sunlight, using a process called chemosynthesis to survive.

Chemosynthesis allows organisms to convert inorganic molecules into energy using chemicals. By harnessing energy from inorganic compounds, these organisms can thrive and support a rich ecosystem in such areas.

At hydrothermal vents, the energy from the breakdown of hydrogen sulfide, a common compound in vent plumes, drives chemosynthesis, according to the National Oceanic and Atmospheric Administration.

"The Indian Ocean has the Central and Southern Indian Ocean Ridges where magma emerges from the mantle. The magma cools due to the seawater and interacts with it. As a result, many minerals and rare metals, including those essential for future technologies like nickel, manganese, and cobalt, are formed there," Meloth told PTI.

These ridges are like underwater mountain ranges, as rugged as the Himalayas. Exploring them is extremely challenging due to the depth -- about 3,000 to 5,000 metres -- and the complete darkness, Meloth explained.

"It is like searching for a needle in hundreds of haystacks," he said.

The team relied on an Autonomous Underwater Vehicle (AUV), a self-programmed robotic instrument capable of smoothly navigating the rugged underwater terrain, capturing high-resolution images and collecting data.

NIOT Director Balaji Ramakrishnan told PTI that India conducted four expeditions over the last two years in the region to locate the hydrothermal vent.

"The objective of this expedition was to capture images of the hydrothermal vent and conduct additional engineering studies to gather parameters useful for our investigations," he said.

Ramakrishnan said the scientists are yet to analyse the complete set of videos, photographs, and samples they have collected, among other data.

The scientists said that hydrothermal vents are not just mineral treasure troves; they are also cradles of unique ecosystems.

Unlike most life on Earth which depends on sunlight, deep-sea organisms rely on chemosynthesis, a process that uses chemicals like hydrogen sulfide to generate energy.

"The animals living around hydrothermal vents make their living from the chemicals coming out of the seafloor," Meloth explained.

This discovery opens doors for Indian scientists to study life forms that exist in extreme conditions. These organisms could provide insights into the origins of life on Earth.

Russian biochemist Aleksandr Oparin in 1922 proposed a chemosynthetic theory of the origin of life which says that "life might have originated at first on earth through a series of combinations of chemical substances in the distant past and it all happened in water".

However, conducting research in the deep ocean comes with its share of challenges, Meloth said.

"The weather in the Southern Ocean is a major challenge. Ocean currents and extremely windy conditions can make it difficult to launch operations. Even during a one-month survey, we might get only one or two weeks of suitable weather," he said.

Adding to the difficulty is the sheer scale of the search. Hydrothermal vents are often small, about one or two meters wide, scattered across thousands of km of ocean, he said.

"The instruments need to be incredibly precise to locate these vents. It requires a mix of experience and a bit of luck," Meloth added.