Oceans cover the majority of our planet and provide countless environmental, health, economic, and cultural benefits. To mark their importance – and encourage everyone to help keep them healthy – World Ocean Day is observed on June 8. In celebration of this occasion, learn more about them!

They’re Deeper Than Any Poetry You’ve Read

We all know the oceans’ depths are impressive, but just how impressive they are is staggering. The deepest part of any ocean – called the Challenger Deep – is about 36,000 feet and located in the western Pacific within the Mariana Trench. It’s such a different world down there that the pressure is eight tons per square inch. In comparison, the average sea level air pressure is about 15 pounds per square inch. It’s also tens of thousands of feet past the point at which surface light stops penetrating the water: at about 3300 feet.

They’ve Inspired Plenty of Superstitions

Sailors have spent thousands of years traversing the high seas, and their time out there has led to quite a few interesting superstitions. Among them are that flat-footed people, women, redheads, and bananas are all bad luck aboard a ship. There is an exception for naked women, who are thought to calm the sea. It is also believed that turning things upside down could capsize a ship, that whistling could “whistle up a storm”, and that seagulls carry the souls of departed sailors.

They’ve Also Inspired Myths

Along with superstitions, the oceans are the origin of a large number of myths. There are the standard stories of deities who live within them, across a variety of cultures, but there are also interesting creatures whose stories have been conjured up by sailors who have spent a long time away from land. Those include the Kraken and other squid-like creatures thought to wreak havoc on ships, as well as mermaids, who are sometimes thought of us as good luck or a symbol of fertility but are sometimes feared as seductresses who lure sailors to their deaths.

We’ve Explored Very Little of Them

Though the oceans are so vast, covering about 70% of our planet, our knowledge of them is fairly limited. According to the National Oceanic and Atmospheric Administration, only about a quarter of the global seafloor has been mapped. It’s quite a diverse area, too. The seafloor includes a wide array of landscapes, including geologically active sites, where magma emerges from between tectonic plates.

How Many Creatures Live There? Who Knows?

Much like the seafloor, sea life is a bit of a mystery to us. At the moment, about a quarter of a million species have been identified, but scientists know that’s just a drop in the bucket compared to the overall number. It’s thought to be up to a million, with at least two-thirds awaiting discovery.

They Heal Us and Help Us Breathe

It’s well known that nature is a helpful source for medications, and the nature below the waterline is much the same. Marine ingredients are found in many medicines, including those for a variety of cancers, Alzheimer’s, and skin issues. Coral is also helpful for human bone grafting. Oceans are responsible for putting air in our lungs, as well. They produce at least half of the Earth’s oxygen, primarily through phytoplankton.

They Feed Us in a Variety of Ways

When people think of food from the oceans, it’s generally fish. That’s a fair assessment, as the oceans produce about 15% of the animal protein eaten across the globe. However, it doesn’t stop there. We also eat plants from our oceans, including eelgrass – known as the rice of the sea. There are marine ingredients in other foods, too. One such ingredient is carrageenan. Derived from red algae, it’s added to foods and beverages like peanut butter, non-dairy milks, and ice cream to thicken them.

They May Help with Renewable Energy

As the world pushes toward more clean energy sources, the oceans may be a key ally. There are currently a few ways we’ve discovered that the ocean can help produce energy. Those include through tidal streams and ocean currents, thermal energy conversion, and using the meeting of fresh and saltwater for salinity gradient power.

They’re Climate Regulators

Even without clean energy, our oceans are integral to our environment. They account for well over 95% of our planet’s water, and they regulate climate and weather patterns by transporting heat from the equator to the poles. In fact, they take up more than 90% of the excess heat in the climate system. They also absorb about a quarter of all carbon emissions.

They Face Threats

Unfortunately, these important resources, and their mysteries we’ve yet to discover, are at risk. Pollution is a big issue, with roughly eight million tons of plastic ending up in our oceans each year. More than 80% of marine pollution comes from land, as well, and may come in the form of run-off.

Overfishing is also a major threat, with about a third of key commercial species falling victim, while an estimated 60% are fished at the maximum sustainable level. Carbon dioxide levels are going up, as well, which can increase acidity, and, as temperatures rise due to climate change, more species are at risk, including coral.

Further threats include ocean noise, habitat disturbances, offshore drilling, and deep-sea mining.

If you’d like to do your part to help, join us as we work with partners to save our oceans!