48more facts about our oceans
(48حقيقةاخرى عن المحيطات )
- The oceans occupy nearly 71% of our planet's surface
- More than 97% of all our planet's water is contained in the ocean
- The top ten feet of the ocean hold as much heat as our entire atmosphere
- The average depth of the ocean is more than 2.5 miles
- The oceans provide 99 percent of the Earth's living space- the largest space in our universe known to be inhabited by living organisms
- More than 90% of this habitat exists in the deep sea known as the abyss
- Less than 10% of this living space has been explored by humans
- 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)
- The longest continuous mountain chain known to exist in the Universe resides in the ocean at more than 40,000 miles long
- The Monterey Bay Submarine Canyon is deeper and larger in volume than the Grand Canyon
- The Antarctic ice sheet that forms and melts over the ocean each year is nearly twice the size of the United States
- The average temperature of the oceans is 2ºC, about 39ºF
- 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.
- 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
- The worlds oceans contain nearly 20 million tons of gold
- The color blue is least absorbed by seawater; the same shade of blue is most absorbed by microscopic plants, called phytoplankton, drifting in seawater
- A new form of life, based on chemical energy rather than light energy, resides in deep-sea hydrothermal vents along mid-ocean ridges
- A swallow of seawater may contain millions of bacterial cells, hundreds of thousands of phytoplankton and tens of thousands of zooplankton
- 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
- The gray whale migrates more than 10,000 miles each year, the longest migration of any mammal
- The Great Barrier Reef, measuring 1,243 miles, is the largest living structure on Earth. It can be seen from the Moon.
- More than 90 percent of the trade between countries is carried by ships and about half the communications between nations use underwater cables
- 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
- Fish supply the greatest percentage of the world's protein consumed by humans
- Most of the world's major fisheries are being fished at levels above their maximum sustainable yield; some regions are severely overfished
- The Grand Banks, the pride of New England fishing for centuries, are closed due to overfishing
- Eighty per cent of all pollution in seas and oceans comes from land-based activities.
- Three-quarters of the world's mega-cities are by the sea.
- By 2010, 80 per cent of people will live within 60 miles of the coast.
- 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.
- 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.
- 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.
- 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.
- 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.
- There are about 4,000 coral reef fish species worldwide, accounting for approximately a quarter of all marine fish species.
- Nearly 60 per cent of the world's remaining reefs are at significant risk of being lost in the next three decades.
- The major causes of coral reef decline are coastal development, sedimentation, destructive fishing practices, pollution, tourism and global warming.
- Less than one half a per cent of marine habitats are protected -- compared with 11.5 per cent of global land area.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- The annual global by-catch mortality of small whales, dolphins and porpoises alone is estimated to be more than 300,000 individuals.
- 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.
good luck
Mohamed Hassaan
No comments:
Post a Comment