FEATURE | International alliance conducts deep-sea research mission in Maldives

An alliance of international partners has completed a systematic survey of ocean life in the Maldives, covering an area between the surface of the Indian Ocean to depths of as much as 1,000 metres.

The University of Oxford said the effort will enable the Maldivian government to develop conservation and sustainable development policies for the benefit of the Maldivian people. Almost nothing is known about what is below 30 metres, the vast majority of the country.

The Nekton Maldives Mission deployed two advanced human-crewed submersibles, robotic and autonomous systems, and more than a dozen research technologies. The university said this makes it one of the most technically varied and advanced missions ever undertaken in the Indian Ocean.

A range of key objectives

Lucy Woodall, Associate Professor of Marine Biology at the University of Oxford and Principal Scientist at Nekton, led the international science team. Associate Professor Woodall said collaborations of this nature allow expeditions to be designed around the needs of a country, hence enabling the gathering of the necessary information for that country's officials to make important decisions around conservation and marine protection. She added that this particular expedition will lead to the development of themes of important research priorities by capturing information such as environmental parameters and benthic mapping, which was done for the first time in this area of the world.

Coordinated and managed by Nekton, a not-for-profit research institute based at Begbroke Science Park in Oxford, the expedition is an international endeavour, involving an alliance of 40 organisations with a scientific team drawn from the Maldives, UK, Seychelles, India, Sri Lanka, South Africa, Spain, Greece, Netherlands, and Ireland. Ten Maldivian marine scientists have been selected to be the first Maldivian aquanauts to lead over 30 descents in the mission's submersibles.

Specific aims of the project include the following:

• Determine the location, health and resilience of the coral reefs that are essential to life in the Maldives.
• Investigate how ocean life adapted to historic rising sea levels caused by ice melt from the last Ice Age.
• Explore the largely unknown and unprotected deep corals and reefs of the Rariphotic Zone, which acts as a refuge to animals from shallower waters.
• Investigate the relative abundance of the 40 shark species and 18 ray species at the apex of the food chain in Maldives waters, as the numbers of the species act as critical indicators of ocean health.
• Conduct the first mapping survey of a subsea mountain in the Northern Indian Ocean.

Purpose-designed marine research vessels and equipment

A number of seagoing assets supplied by various partner organisations were deployed for the expedition:

• Odyssey – The expedition's main research vessel/mothership combines state of the art oceanographic, exploration, scientific and filmmaking capabilities including a seabed mapping system, wet labs, dry labs, an onboard medical facility, a hyperbaric chamber, a sophisticated mission-control centre, and a broadcast-quality studio. Odyssey was supplied by the Ocean Conservation, Exploration and Education Foundation (OCEEF).
• Omega Seamaster II – A three-person submersible built by Florida-based Triton Submarines, the craft is equipped with a suite of five different cameras for documenting biodiversity, scanning sonar, ultra-short baseline positioning systems, a manipulator arm and biobox for sampling. The submersible also has an endurance of eight hours.
• Aurelia – Another Triton-built three-person submersible, the craft is owned by Norwegian marine research non-profit REV Ocean. It has an endurance of over 10 hours and is equipped with six different camera systems, a scanning sonar, a manipulator, suction sampling tools, bioboxes, and sensors.
• Remotely operated vehicles (ROVs) – The Nekton team also deployed camera-equipped ROVs supplied by Sweden's Saab Seaeye and the UK Natural History Museum.

The other key pieces of equipment are multi-beam mapping sensors, baited remote underwater video systems, conductivity, temperature and depth (CTD) measuring sensors, and specialised nets for sampling for zooplankton, which Nekton said is essential to the marine food web.

After-mission activities

Conducted in September and October 2022, the Nekton Maldives Mission is now focused on preparing its findings for publication. The first results from the expedition are scheduled to be published in the middle of this year.

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