Our relationship with the ocean is on rocky shores. A 2021 report found that the world’s oceans are damaged almost beyond repair: “dead zones” with insufficient oxygen for life are increasing, and around 90 percent of all marsh plant species and mangroves are threatened with extinction.
Human activity and our exploitative economic systems pose the greatest threat to a healthy ocean through climate change, overfishing, pollution and habitat destruction, among other negative impacts. What’s more, the extent of these threats is still poorly understood, as countries devote an average of just 4 percent of their research and development budgets to ocean science.
Despite its problems, this relationship is worth fighting for – if only for selfish reasons, like giving future generations enough fish to eat and oxygen to breath.
The UN Decade for Ocean Science for Sustainable Development, which began in 2021, is one attempt at reconciliation that has made some headway. A new ‘high seas treaty’, signed this March, is the first of its kind to protect international waters outside national boundaries and is crucial step towards protecting a third of the Earth’s sea and land areas by 2030.
We all have a part to play in patching things up – and it can all start by getting ourselves informed. Here are our top 10 ocean facts to make you fall in love with the deep blue sea.
The ocean is the Earth’s greatest source of oxygen
Kelp, algae and tiny ocean phytoplankton are responsible for producing about 70 percent of all atmospheric oxygen. The ocean also absorbs about a third of all carbon dioxide produced on Earth and stores 50 times more carbon dioxide than the atmosphere. However, as the ocean absorb more and more carbon dioxide, its water is acidifying, making it more difficult for sea creatures to breathe.
Almost all of the Earth’s habitable space is in the ocean.
It’s a well-documented fact that the ocean covers 70 percent of the Earth’s surface. But when we take into account its sheer depth – up to 10 kilometers in the deepest depths of the Pacific – it accounts for over 99 percent of all living space on the planet.
Around 91 percent of ocean species remain undiscovered.
The total number of species that live in the ocean is still unknown, but it’s estimated that there are around 2.2 million marine eukaryotes (plants, animals and fungi), according to this study from 2011. Scientists have identified roughly one new fish species each week since 2015. The 2011 study concluded that a “renewed interest in biological discovery and taxonomy” will be needed to discover them all.
We have better maps of Mars than of the ocean.
Although humans are surrounded by the ocean, more than 80 percent of its depths are “unmapped, unobserved or unexplored,” according to the U.S. National Oceanic and Atmospheric Administration (NOAA). We know the surface of Mars better than our own oceans. This is largely because of how difficult and expensive it is to explore the deep ocean, where the pressure can be up to 1,000 bars – equivalent to the weight of 50 jumbo jets.
The tallest ‘waterfall’ is actually underwater.
Did you know that water falls underwater? The tallest waterfall on Earth is the Denmark Strait cataract, located between Greenland and Iceland, and drops 3,500 m. Compare this to the tallest land-based waterfall, Angel Falls, which drops only 979 m. The Denmark Strait cataract is caused by differences in pressure either side of the strait, where cold water from the Nordic Sea sinks rapidly below the warmer waters from the Irminger Sea at a rate of 5 million cubic meters per second — about 2,000 times faster than Niagara Falls.
Ocean currents help regulate the climate and carry life-sustaining nutrients.
Like the human circulatory system, ocean currents move heat, moisture and nutrients to where they need to be. If these patterns are interrupted, it could have severe consequences for all life on Earth. For example, climate change could cause parts of Northern Europe to go into a deep freeze as climbing global temperatures cause the Atlantic Meridional Overturning Circulation (which includes the Gulf Stream) to slow down, preventing warm currents from reaching Europe at the right times.
About 3 billion people rely on fisheries and other marine species as their main source of protein.
Our damage to the ocean and its habitats could cause food and nutritional insecurity for all the people who rely on fish for their diets, as well as economic hardship for the more than 60 million people employed in fisheries worldwide. Marine protected areas are important tools to preserve fish stocks for future generations through restrictions on bottom-trawl fishing and deep water mining. One notable example is the one surrounding the South Atlantic island of Tristan da Cunha.
More people have been to the moon than the deepest parts of the sea.
Twelve people have been to the moon, but only three people have been to the Marianas Trench – the deepest point in the ocean, inaccessible due to its extreme pressure conditions. One of those three was film director and producer James Cameron.
The world’s largest mountain range is (mostly) underwater.
The mid-oceanic ridge is 65,000 km long – almost eight times longer than the Andes. This monolith mountain chain is 90-percent submerged and passes between all of the world’s continents at an average water depth of 2,500 m.
Arctic fish could teach us to store and preserve food for longer.
The anti-freeze proteins that help fish live in extremely cold temperatures could be harnessed to prevent freezer burn or keep ice crystals from forming in ice cream. More funding for ocean research and conservation could uncover more ingenious applications for human development, but only if the oceans are managed sustainably to ensure that biodiversity doesn’t disappear before it’s even discovered.