A team of international scientists is preparing to carry out a deep sea dive mission into the depths of the Indian Ocean.
The British-led Nekton Mission plans to gather critical data from the so-called "Midnight Zone" - 4,000 metres below surface - where light barely reaches but life still thrives.
Working with the Seychelles and Maldives governments, the five-week expedition is targeting seamounts - vast underwater mountains that rise thousands of metres from the seafloor.
The team is also hoping to observe man-made impacts, such as climate change and plastic pollution.
To reach thousands of metres into the depths of the Indian Ocean, the Nekton scientists will board one of the world’s most advanced submersibles - a small craft designed for underwater dives.
The craft, called Limiting Factor, completed the "Five Deeps Expedition" in August 2019 - diving to the deepest point in each of the world's five oceans.
The deepest dive was almost 11,000 metres down, deeper than Mount Everest is tall.
When "Limiting Factor" descended to the bottom of the Pacific Ocean's Mariana Trench, the ocean's deepest point, the sub's pilot spotted a plastic bag.
- Nekton mission director Oliver Steeds explains why the mission is focusing on the "Midnight Zone"
Nekton mission director Oliver Steeds says the area of focus is "one of the most bio-diverse parts of the world's oceans.
"Beneath 1,000 metres (3,280 feet), there’s no light down there, but a lot of animals… are bioluminescent. It’s life that glows," Mr Steeds recently told the Associated Press.
"So what we’re going to find there is unknown".
- How does the watercraft reach the 'Midnight Zone'?
To withstand the crushing pressure thousands of metres beneath the surface, the two-person crew compartment in Limiting Factor is wrapped in a 9cm titanium cocoon.
The compartment also carries up to 96 hours of emergency oxygen.
Expedition leader, Rob McCallum, said: "There are only five vehicles in the world that can get below 6,000 metres and only one that can get to the bottom half.
"So, everything we do is new. Everything we see is virtually a new discovery."
- Expedition leader Rob McCallum on why craft is so unique:
An estimated 2.5 billion people inhabit the regions surrounding the Indian Ocean - from East Africa to the Arabian peninsula, the Indian sub-continent and Southeast Asia.
It's hoped Nekton scientists' conclusions will help island nations protect vast areas of their waters - a part of the world already feeling the effects of global warming.
The Seychelles is expected to announce it has protected 30 per cent of its waters this March. The Maldives government has plans to protect at least 20 per cent of its waters.
- Patrick Lahey is co-founder of Triton Submarines, the company which built the submersible craft:
Using sampling, sensor and mapping technology, Nekton scientists expect to identify new species and towering seamounts, as well as observe man-made impacts, such as climate change and plastic pollution.
"When we actually think of the living space on the planet for species, over 90 per cent of that living space is in the ocean and most of that ocean is unexplored," said Dan Laffoley, a marine expert for the International Union for Conservation of Nature.
"So it’s absolutely critical, at this time when we see such large changes occurring, that we get people down there, we get eyes in the ocean and we see what’s happening," he said.
For now, "Limiting Factor" and its 68-metre mothership, "Pressure Drop", are conducting sea trials in the Mediterranean, before beginning the long journey to the Seychelles.
The main science expedition starts March 16, with the team planning to present their findings in 2022.