World Oceans Day: Mind-Blowing Facts About Our Blue Planet

It's World Oceans Day on Friday June 8, an event coordinated by The Ocean Project, and its goal is to get the world talking about the perilous state of oceans.

Around 2,000 organizations are involved with The Ocean Project, including aquariums, zoos and museums. Their focus for World Oceans Day 2018? "Preventing plastic pollution and encouraging solutions for a healthy ocean," according to the official website.

Plastic pollution is a huge problem in our oceans. Waste plastic created by humans finds its way into the water, contaminating and killing the wealth of life within it. Ocean campaigners are pushing for governments to take responsibility for the state of our waters before the current crisis gets any worse.

To mark World Oceans Day 2018, here are some mind-blowing and alarming facts about the ocean that should both inspire and worry you.

ocean plastic
Plastic bottles and other waste cover a beach after being washed ashore near the port city of Abidjan, Ivory Coast, on August 5, 2015. It’s World Oceans Day on June 8. Ocean campaigners are pushing for governments to take responsibility for the state of our waters before the current crisis gets any worse. ISSOUF SANOGO/AFP/Getty Images

About 70 percent of the world is covered by oceans, equating to 361.9 million square kilometers, according to the National Oceanic and Atmospheric Administration (NOAA). In volume terms, the ocean's total size is 1.335 billion cubic kilometers. We're talking about huge numbers.

That is why humans have only successfully explored around 5 percent of the entire ocean. The World Register of Marine Species has identified 228,445 species of marine creatures. But researchers estimate between 500,000 and 2 million marine species remain to be discovered—and many are at risk of extinction even before we do because of climate change.

A 2015 study published in the journal Environmental Research Letters estimated the number of microplastic particles—the tiny fragments of plastic often ingested by marine life—ranges between 15 to 51 trillion particles. In weight terms, that equates to between 93 and 236 thousand metric tons. Alarmingly, the study also said this is only approximately 1 percent of the total global plastic waste estimated to enter the ocean in the year 2010 alone.

According to The International Union for Conservation of Nature, the ocean's coral reefs account for just 0.25 percent of the marine environment, yet they are home to over 25 percent of all known marine fish species. Coral reefs are in a death spiral. Coral bleaching—the death of a reef—used to occur around every 30 years. It takes 10 years for that coral to rejuvenate to maturity again.

But a study of 100 reefs published in the journal Science in 2018 found that coral bleaching is occurring once every five or six years, because of rising sea temperatures caused by human-driven global warming—meaning they cannot fully recover.

The sea surface temperature rose at an average rate of 0.13 degrees per decade from 1901 to 2015, according to NOAA, and has been consistently higher during the past three decades than at any other time since 1880. However, in the North Atlantic, sea surface temperatures are actually cooling. Some scientists believe this is because the warming climate is melting the Arctic ice caps.

Ocean acidity is another big concern. The world is pumping out carbon dioxide by burning fossil fuels, much of which is absorbed into the oceans, sparking a reaction that forms carbonic acid.

For hundreds of millions of years, the ocean's pH level was 8.2. Since industrialization, the ocean's pH has fallen to 8.1 as acid levels in the water rise. A change that should have taken tens of thousands of years has instead occurred in just 200. And it could have a devastating impact on marine life. Acidity will make it harder for creatures such as shellfish to form their exoskeletons, for example.