Ocean Facts Which You Must Know.

The Earth’s oceans are odd, beautiful and intriguing — and we know surprisingly little about them. Learn why oceans comprise a strange and wonderful world all their own.

The oceans may make up 70 percent of the Earth’s surface, but we know very little about them, especially compared to our knowledge of the Earth’s land spaces — or even those of Mars and Venus. Consider this: We made it all the way to the moon a full four years before we saw the largest mountain range on Earth, lying below the oceans' surface.
To give you an idea of the numerous surprises that dwell in the oceans, and hopefully make you eager to learn more, here are 15 fun tidbits about the awe-inspiring world that lies below the oceans’ surface.

Interesting Ocean Facts

Area: about 140 million square miles (362 million sq km), or nearly 71% of the Earth's surface.

Average Depth: 12,200 feet (3,720 m).
Deepest point: 36,198 feet (11,033 m) in the Mariana Trench in the western Pacific.
Mountains: The ocean ridges form a great mountain range, almost 40,000 miles (64,000 km) long, that weaves its way through all the major oceans. It is the largest single feature on Earth.
Highest Mountain: Mauna Kea, Hawaii, rises 33,474 feet (10,203 m) from its base on the ocean floor; only 13,680 feet (4,170 m) are above sea level.

Some Other Interesting Ocean Facts

1. For starters, did you know that 94 percent of life on Earth is aquatic? That makes us land-dwellers a very small minority.
   
2. About 70 percent of the planet is ocean, with an average depth of more than 12,400 feet. Given that photons (light) can’t penetrate more than 330 feet below the water’s surface, most of our planet is in a perpetual state of darkness.
3. Fifty percent of the United States (in terms of our complete legal jurisdiction, which includes ocean territory) lies below the ocean.
4. The deep sea is the largest museum on Earth: There are more artifacts and remnants of history in the ocean than in all of the world’s museums, combined.
5. We have only explored less than 5 percent of the Earth’s oceans. In fact, we have better maps of Mars than we do of the ocean floor (even the submerged half of the United States). 
6.  The longest mountain range in the world is under water. Called the Mid-Oceanic Ridge, this chain of mountains runs through the middle of the Atlantic Ocean and into the Indian and Pacific oceans. It runs more than 35,000 miles long, has peaks higher than those in the Alps and it comprises 23 percent of the Earth’s total surface.
7.  We didn’t send divers down to explore the Mid-Ocean Ridge until 1973 — four years after Neil Armstrong and Buzz Aldrin walked on the moon — when a French-American crew of seven entered the 9,000-foot-deep Great Rift in the French submersible Archimede.
8.  The ocean boasts an array of unusual geographic features, such as pillars that reach several stories high and chimneys that send up sulphuric acid. In the ocean-floor neighborhood of the Gulf of Mexico, brine pools mark the floor, along with underwater volcanoes that spew mud and methane, rather than lava.
9. These wonderful formations aren’t barren, either. Underwater hot springs that shoot water that’s 650 degrees Fahrenheit — hot enough to melt lead — boast a profusion of life, from 10-foot tall tubeworms to giant clams that function without digestive systems.
10. The oceans occupy nearly 71% of our planet's surface
    
11. More than 97% of all our planet's water is contained in the ocean
12. The top ten feet of the ocean hold as much heat as our entire atmosphere
13. The average depth of the ocean is more than 2.5 miles
14. The oceans provide 99 percent of the Earth's living space- the largest space in our universe known to be inhabited by living organisms
15. More than 90% of this habitat exists in the deep sea known as the abyss
16. Less than 10% of this living space has been explored by humans
17. Mount Everest (the highest point on the Earth's surface 5.49 miles) is more than 1 mile shorter than the Challenger Deep (the deepest point in the ocean at 6.86 miles)
18. The longest continuous mountain chain known to exist in the Universe resides in the ocean at more than 40,000 miles long
19. The Monterey Bay Submarine Canyon is deeper and larger in volume than the Grand Canyon
20. The Antarctic ice sheet that forms and melts over the ocean each year is nearly twice the size of the United States
21. The average temperature of the oceans is 2ºC, about 39ºF
22. Water pressure at the deepest point in the ocean is more than 8 tons per square inch, the equivalent of one person trying to hold 50 jumbo jets.
23. The Gulf Stream off the Atlantic seaboard of the United States flows at a rate nearly 300 times faster than the typical flow of the Amazon river, the world's largest river
24. The worlds oceans contain nearly 20 million tons of gold
    
25. The color blue is least absorbed by seawater; the same shade of blue is most absorbed by microscopic plants, called phytoplankton, drifting in seawater
26. A new form of life, based on chemical energy rather than light energy, resides in deep-sea hydrothermal vents along mid-ocean ridges
27. A swallow of seawater may contain millions of bacterial cells, hundreds of thousands of phytoplankton and tens of thousands of zooplankton
28. The blue whale, the largest animal on our planet ever (exceeding the size of the greatest dinosaurs) still lives in the ocean; it's heart is the size of a Volkswagen
29. The gray whale migrates more than 10,000 miles each year, the longest migration of any mammal
    
30. The Great Barrier Reef, measuring 1,243 miles, is the largest living structure on Earth. It can be seen from the Moon.
31. More than 90 percent of the trade between countries is carried by ships and about half the communications between nations use underwater cables
32. More oil reaches the oceans each year as a result of leaking automobiles and other non-point sources than was spilled in Prince William Sound by the Exxon Valdez
33. Fish supply the greatest percentage of the world's protein consumed by humans
34. Most of the world's major fisheries are being fished at levels above their maximum sustainable yield; some regions are severely overfished
35. The Grand Banks, the pride of New England fishing for centuries, are closed due to overfishing
36. Eighty per cent of all pollution in seas and oceans comes from land-based activities.
37. Three-quarters of the world's mega-cities are by the sea.
38. By 2010, 80 per cent of people will live within 60 miles of the coast.
39. Death and disease caused by polluted coastal waters costs the global economy US$12.8 billion a year. The annual economic impact of hepatitis from tainted seafood alone is US$7.2 billion.
40. Plastic waste kills up to 1 million sea birds, 100,000 sea mammals and countless fish each year. Plastic remains in our ecosystem for years harming thousands of sea creatures everyday.
41. Over the past decade, an average of 600,000 barrels of oil a year has been accidentally spilled from ships, the equivalent of 12 disasters the size of the sinking of the oil tanker Prestige in 2002.
42. Tropical coral reefs border the shores of 109 countries, the majority of which are among the world's least developed. Significant reef degradation has occurred in 93 countries.
43. Although coral reefs comprise less than 0.5 per cent of the ocean floor, it is estimated that more than 90 per cent of marine species are directly or indirectly dependent on them.
44. There are about 4,000 coral reef fish species worldwide, accounting for approximately a quarter of all marine fish species.
45. Nearly 60 per cent of the world's remaining reefs are at significant risk of being lost in the next three decades.
    
46. The major causes of coral reef decline are coastal development, sedimentation, destructive fishing practices, pollution, tourism and global warming.
47. Less than one half a per cent of marine habitats are protected -- compared with 11.5 per cent of global land area.
48. The High Seas -- areas of the ocean beyond national jurisdiction -- cover almost 50 per cent of the Earth's surface. They are the least protected part of the world.
49. Although there are some treaties that protect ocean-going species such as whales, as well as some fisheries agreements, there are no protected areas in the High Seas.
50. Studies show that protecting critical marine habitats -- such as warm-and cold-water coral reefs, seagrass beds and mangroves -- can dramatically increase fish size and quantity.
51. More than 3.5 billion people depend on the ocean for their primary source of food. In 20 years, this number could double to 7 billion.
52. Populations of commercially attractive large fish, such as tuna, cod, swordfish and marlin have declined by as much as 90 per cent in the past century.
53. Each year, illegal longline fishing, which involves lines up to 80 miles long, with thousands of baited hooks, kills over 300,000 seabirds, including 100,000 albatrosses.
54. As many as 100 million sharks are killed each year for their meat and fins, which are used for shark fin soup. Hunters typically catch the sharks, de-fin them while alive and throw them back into the ocean where they either drown or bleed to death.
55. Global by-catch -- unintended destruction caused by the use of non-selective fishing gear, such as trawl nets, longlines and gillnets -- amounts to 20 million tons a year.
56. The annual global by-catch mortality of small whales, dolphins and porpoises alone is estimated to be more than 300,000 individuals.
57. Fishing for wild shrimp represents 2 per cent of global seafood but one-third of total by-catch. The ratio of by-catch from shrimp fishing ranges from 5:1 in temperate zones to 10:1 and more in the tropics. 
58.  Many of the rules that apply on land are turned upside down in the ocean, some literally. Beneath the surface, often not far from popular vacation beaches, are underwater lakes, waterfalls and even upside-down lakes! (You might have to see it to believe it. Check out Gallo’s video of Underwater Astonishments to see a wealth of underwater marvels.)
59.  Much of the life in the oceans, as on land, is invisible to the naked eye. For instance, if you’ve ever swallowed a milliliter of ocean water, know that you also gulped 1 million bacteria and 10 million viruses — give or take a few. No need to worry though, swimmers around the world swallow some ocean water during their ventures into the water, without ill effects.
60.  Also living on hydrothermal vents are 140- to 160-foot long jellies, which use a process called chemosynthesis (think photosynthesis, but adapted to zero sunlight) to convert the hydrothermal water into simple sugars for food. Most striking are the extremes in which the jellies live. Temperatures vary drastically near the vents, so while the tops of the jellies enjoy lows of 37 degrees, their bottoms (at the vent) bask in a toasty 392 degrees — happy as clams, or jellies, rather.