How Much of the Ocean Is Unexplored?

The oceans make up around 70% of planet Earth, yet over 80% of the world's ocean remains unexplored. Since the global boom of ocean exploration technology began in the 1960s, deep-sea exploration has faced a number of barriers. Today, with fewer barriers in place than ever before, international efforts are underway to continue the exploration of the deep ocean.


Barriers to Ocean Exploration

Exploring the ocean is both expensive and technologically challenging—for reasons that are not so surprising. Robots created for deep-sea ocean exploration must be able to withstand the high pressure that comes with depth, operate without the need for maintenance for thousands of hours at a time, and be able to resist the corrosive effects of seawater.

Extreme Pressure

On average, the ocean is about 12,100 feet deep. At this depth, the pressure inflicted by the weight of the seawater above is over 300-times greater than the pressure we experience at the ocean's surface. At the deepest part of the ocean, about 36,000 feet below the surface, the pressure is over 1,000-times greater than the pressure at the ocean's surface.

Devices used for underwater exploration must be designed to withstand the intense pressure of the deep ocean. Submersibles designed to carry people aboard must also have the capacity to maintain an internal pressure compatible with what the human body can withstand. Typically, these manned submersibles use pressure hulls to control internal pressure.

However, these hulls can account for nearly a third of the total weight of the submersible, limiting the machine's capabilities. Until recently, the intense pressure in the deep ocean has been one hurdle preventing people from exploring the abyss directly.

Long Dives

It can take many hours for a submersible to get down to a target depth, let alone explore the environment. Given the substantial amount of time a submersible must remain underwater, all underwater robots must be built to be self-sufficient in a variety of circumstances.

There are three main types of robots used to explore the deep ocean: human-operated vehicles (HOVs), remotely-operated vehicles (ROVs), and autonomous underwater vehicles (AUVs). HOVs are submersibles designed to have people on board, whereas ROVs are operated by people remotely, typically from a ship at the surface. AUVs, on the other hand, are designed to be completely autonomous, exploring the ocean through pre-programmed missions. Once each mission is completed, the AUV returns to the surface for retrieval, at which point scientists get to process the data the AUV collected during its journey.

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Marine heatwave sends NSW ocean temperatures soaring to levels not seen in decades

A marine heatwave is lifting ocean temperatures off the coast of New South Wales to levels not seen in decades as the state is pummelled by severe storms.
The marine temperatures appear to be reaching levels not seen in nearly 80 years, with satellite data showing ocean surfaces three degrees Celcius above normal.
Professor Moninya Roughan said ocean temperatures at a site five kilometres from Port Hacking, Sydney, are approaching an all-time high for January.

Is deep-sea mining a cure for the climate crisis or a curse?

Trillions of metallic nodules on the sea floor could help stop global heating, but mining them may damage ocean ecology,

In a display cabinet in the recently opened Our Broken Planet exhibition in London’s Natural History Museum, curators have placed a small nugget of dark material covered with faint indentations. The blackened lump could easily be mistaken for coal. Its true nature is much more intriguing, however.

The nugget is a polymetallic nodule and oceanographers have discovered trillions of them litter Earth’s ocean floors. Each is rich in manganese, nickel, cobalt and copper, some of the most important ingredients for making the electric cars, wind turbines and solar panels that we need to replace the carbon-emitting lorries, power plants and factories now wrecking our climate.

These metallic morsels could therefore help humanity save itself from the ravages of global warming, argue mining companies who say their extraction should be rated an international priority. By dredging up nodules from the deep we can slow the scorching of our planet’s ravaged surface.

“We desperately need substantial amounts of manganese, nickel, cobalt and copper to build electric cars and power plants,” says Hans Smit, chief executive of Florida’s Oceans Minerals, which has announced plans to mine for nodules. “We cannot increase land supplies of these metals without having a significant environmental impact. The only alternative lies in the ocean.”

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Overfishing: driving extinction (The latest IUCN Red List assessments for sharks and rays are in, and it’s official: overfishing is driving extinction).

For the first time since the initial IUCN Red List assessment, scientists, including the Save Our Seas/Ocean Foundation’s Project Leaders, have reassessed the extinction risk to all 1,199 chondrichthyan* species. And the news is bad. Despite having survived at least five mass extinctions during their 420-million-year history, more than two-thirds (37.5%) are now estimated to be threatened with extinction. That’s up from around a quarter (24%) in 2014.

From the majestic reef manta ray to the giant great hammerhead shark, and even the bioluminescent velvet belly lanternshark, they all have one thing in common: they’re caught (often unintentionally) in fisheries, and it’s threatening their survival.


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‘Great Blue Wall’ aims to ward off looming threats to western Indian Ocean

Ten countries in the western Indian Ocean are banding together to create a network of marine conservation areas under the banner of the Great Blue Wall.

The idea is to push through conservation areas, including those that straddle national boundaries, to bridge the gap between how much of the ocean is protected and how much needs to be secured. A recent assessment revealed the cost of failing to do so: coral reefs in the region are at high risk of collapsing in the next 50 years.

“Most of what needs to be done is already happening, governments are creating Marine Protected Areas [MPAs], local communities are setting up locally managed marine areas,” said Thomas Sberna, a regional head for Eastern and Southern Africa at global conservation authority the IUCN. “But is it happening fast enough, is it big enough? No.”

Only around 5-8% of the marine area in the Indian Ocean is under some form of legal protection, a far cry from the goal of protecting 30% of Earth’s land and oceans by 2030. Known as “30 by 30,” this goal has gained traction globally ahead of a landmark biodiversity summit this year.


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Newly appointed group of global experts will help drive Ocean Decade action on data, information and knowledge management

At the first meeting of the Ocean Decade Data Coordination Group on December 16th, 2021, twenty-five (25) expert members expressed a strong commitment to transforming the UN initiative into a true “knowledge revolution” as they help co-deliver ambitious ocean data and information goals for sustainable development.

Established under by the Secretariat of the Intergovernmental Oceanographic Commission of UNESCO, the UN body responsible for coordinating the UN Decade of Ocean Science for Sustainable Development (2021-2030, ‘the Ocean Decade), the Data Coordination Group brings together 25 experts from 12 countries. These experts represent various industries, fields and stakeholder groups who will work to reinforce and focus efforts to significantly enhance ocean data and information over the course of the Decade.


“The success of the Ocean Decade will very much depend on our ability to generate, digitize, preserve, manage, openly exchange and, most importantly, significantly increase the usefulness volume and range of ocean data, information and knowledge, so it may guide decisions and policy choices for sustainable ocean planning and management,” said Vladimir Ryabinin, IOC-UNESCO Executive Secretary.

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