Great white sharks, Carcharodon carcharias, aka white sharks, white pointers, blue pointers, man-eaters, manila sharks, have, according to E.O. Wilson "...rightfully been called a top carnivore, a killing machine, the last free predator of man—the most frightening animal on earth."
Great white sharks are the largest known predatory fishes in the sea. They reach lengths of over 6.1 m and weigh up to 2,268 kg. They have conical snouts, pitch black eyes, heavy torpedo-shaped bodies, and a crescent-shaped, nearly equal-lobed tail. More...
Ocean Facts
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Sharks attack some 50-75 people each year worldwide, with perhaps 8-12 fatalities, according to data compiled in the International Shark Attack File (ISAF). Although shark attacks get a lot of attention, this is far less than the number of people killed each year by elephants, bees, crocodiles, lightning or many other natural dangers. On the other side of the ledger, we kill somewhere between 20-100 million sharks every year through fishing activities.
Of the 350 or so shark species, about 80% grow to less than 1.6 m and are unable to hurt people or rarely encounter people. Only 32 species have been documented in attacks on humans, and an additional 36 species are considered potentially dangerous.
Almost any shark 1.8 m or longer is a potential danger, but three species have been identified repeatedly in attacks: the great white, tiger, and bull sharks. All three are found worldwide, reach large sizes and eat large prey such as marine mammals or sea turtles. More attacks on swimmers, free divers, scuba divers, surfers and boats have been reported for the great white shark than for any other species. However, some 80% of all shark attacks probably occur in the tropics and subtropics, where other shark species dominate and Great white sharks are relatively rare.
An estimated 50-80% of all life on earth is found under the ocean surface and the oceans contain 99% of the living space on the planet. Less than 10% of that space has been explored by humans. 85% of the area and 90% of the volume constitute the dark, cold environment we call the deep sea. The average depth of the ocean is 3,795 m. The average height of the land is 840 m.
"Currently, scientists have named and successfully classified around 1.5 million species. It is estimated that there are as little as 2 million to as many as 50 million more species that have not yet been found and/or have been incorrectly classified." - SOURCE
According to World Register of Marine Species (WoRMS) there are currently 199,146 named marine species.
So, there are at least 199,146 marine species but there are most likely at least 750,000 marine species (50% of 1.5 million species) and possibly as many as 25 million marine species (50% of 50 million species).
The oceans cover 71% (and rising) of the Earth's surface and contain 97% of the Earth's water. Less than 1% is fresh water, and 2-3% is contained in glaciers and ice caps (and decreasing).
90% of all volcanic activity occurs in the oceans.
The speed of sound in water is 1,435 m/sec - nearly five times faster than the speed of sound in air.
The highest tides in the world are at the Bay of Fundy, which separates New Brunswick from Nova Scotia. At some times of the year the difference between high and low tide is 16.3 m, taller than a three-story building.
Earth's longest mountain range is the Mid-Ocean Ridge more than 50,000 km in length, which winds around the globe from the Arctic Ocean to the Atlantic, skirting Africa, Asia and Australia, and crossing the Pacific to the west coast of North America. It is four times longer than the Andes, Rockies, and Himalayas combined.
The pressure at the deepest point in the ocean is more than 11,318 tons/sq m, or the equivalent of one person trying to support 50 jumbo jets.
The top ten feet of the ocean hold as much heat as the entire atmosphere.
The lowest known point on Earth, called the Challenger Deep, is 11,034 m deep, in the Marianas Trench in the western Pacific. To get an idea of how deep that is, if you could take Mt. Everest and place it at the bottom of the trench there would still be over a mile of ocean above it. The Dead Sea is the Earth's lowest land point with an elevation of 396 m below sea level.
Undersea earthquakes, volcanoes and landslides can cause tsunamis (Japanese word meaning "harbor wave"), or seismic sea waves. The largest recorded tsunami measured 60 m above sea level caused by an 8.9 magnitude earthquake in the gulf of Alaska in 1899 traveling at hundreds of km/hr.
The average depth of the Atlantic Ocean, with its adjacent seas, is 3,332 m; without them it is 3,926 m. The greatest depth, 8,381 m, is in the Puerto Rico Trench.
The Pacific Ocean, the world's largest water body, occupies a third of the Earth's surface. The Pacific contains about 25,000 islands (more than the total number in the rest of the world's oceans combined), almost all of which are found south of the equator. The Pacific covers an area of 179.7 million sq km.
The Kuroshio Current, off the shores of Japan, is the largest current. It can travel between 40-121 km/day at 1.6-4.8 kph, and extends some 1,006 m deep. The Gulf Stream is close to this current's speed. The Gulf Stream is a well known current of warm water in the Atlantic Ocean. At a speed of 97 km/day, the Gulf Stream moves a 100 times as much water as all the rivers on earth and flows at a rate 300 times faster than the Amazon, which is the world's largest river.
A given area in an ocean upwelling zone or deep estuary is as productive as the same area in rain forests, most crops and intensive agriculture. They all produce between 150-500 grams of Carbon per square meter per year.
The sea level has risen with an average of 10-25 cm over the past 100 years and scientists expect this rate to increase. Sea levels will continue rising even if the climate has stabilized, because the ocean reacts slowly to changes. 10,000 years ago the ocean level was about 110 m lower than it is now. If all the world's ice melted, the oceans would rise 66 m.
The density of sea water becomes more dense as it becomes colder, right down to its freezing point of -1.9°C unlike fresh water which is most dense at 4°C, well above its freezing point of 0°C. The average temperature of all ocean water is about 3.5°C.
Antarctica has as much ice as the Atlantic Ocean has water.
The Arctic produces 10,000-50,000 icebergs annually. The amount produced in the Antarctic regions is inestimable. Icebergs normally have a four-year life-span; they begin entering shipping lanes after about three years.
Air pollution is responsible for 33% of the toxic contaminants that end up in oceans and coastal waters. About 44% of the toxic contaminants come from runoff via rivers and streams.
Each year, three times as much rubbish is dumped into the world's oceans as the weight of fish caught.
Oil is one of the ocean's greatest resources. Nearly one-third of the world's oil comes from offshore fields in our oceans. Areas most popular for oil drilling are the Arabian Gulf, the North Sea and the Gulf of Mexico.
Refined oil is also responsible for polluting the ocean. More oil reaches the oceans each year as a result of leaking automobiles and other non-point sources than the oil spilled in Prince William Sound by the Exxon Valdez or even in the Gulf of Mexico during the Deepwater Horizon/BP oil spill.
The record for the deepest free dive is held by Jacques Mayol. He dove to an astounding depth of 86 m without any breathing equipment.
A mouthful of seawater may contain millions of bacterial cells, hundreds of thousands of phytoplankton and tens of thousands of zooplankton.
The Great Barrier Reef, measuring 2,300 km in length covering an area more extensive than Britain, is the largest living structure on Earth and can be seen from space. Its reefs are made up of 400 species of coral, supporting well over 2,000 different fish, 4,000 species of mollusc and countless other invertebrates. It should really be named 'Great Barrier of Reefs', as it is not one long solid structure but made up of nearly 3,000 individual reefs and 1,000 islands. Other huge barrier reefs include the barrier reefs of New Caledonia, the Mesoamerican (Belize) barrier reef, and the large barrier reefs of Fiji. The largest coral atoll complexes occur in the Maldive-Lakshadweep ecoregion of the central Indian Ocean and in Micronesia.
Fish supply the greatest percentage of the world's protein consumed by humans and most of the world's major fisheries are being fished at levels above their maximum sustainable yield; some regions are severely overfished.
More than 90% of the trade between countries is carried by ships and about half the communications between nations use underwater cables.
The swordfish and marlin are the fastest fish in the ocean reaching speeds up to 121 kph in quick bursts; the bluefin tuna (Thunnus thynnus) may reach sustained speeds up to 90 kph.
Blue whales are the largest animals on our planet ever (exceeding the size of the greatest known dinosaurs) and have hearts the size of small cars.
The oarfish (Regalecus glesne), is the longest bony fish in the world. It has a snakelike body sporting a magnificent red fin and can grow up to 17 m in length, it has a distinctive horselike face and blue gills, and is thought to account for many sea-serpent sightings.
Many fish can change sex during the course of their lives. Others, especially rare deep-sea fish, have both male and female sex organs.
One study of a deep-sea community revealed 898 species from more than 100 families and a dozen phyla in an area about half the size of a tennis court. More than half of these were new to science.
Life began in the seas 3.1 billion to 3.4 billion years ago. Land dwellers appeared approximately 400 million years ago, relatively recently in geologic time.
Because the architecture and chemistry of coral is so similar to human bone, coral has been used to replace bone grafts in helping human bone to heal quickly and cleanly.
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Oceanography News :: ScienceDailyMajor study of ocean acidification helps scientists evaluate effects of atmospheric carbon dioxide on marine life
Might a penguin's next meal be affected by the exhaust from your tailpipe? The answer may be yes, when you add your exhaust fumes to the total amount of carbon dioxide lofted into the atmosphere by humans since the industrial revolution. One-third of that carbon dioxide is absorbed by the world's oceans, making them more acidic and affecting marine life.
Multiple partners not the only way for corals to stay cool
For the first time scientists have shown that corals hosting a single type of zooxanthellae can have different levels of thermal tolerance -– a feature that was only known previously for corals with a mix of zooxanthellae. This finding is important because many species of coral are dominated by a single type of zooxanthellae.
Mysterious flotsam in Gulf of Mexico came from Deepwater Horizon rig
Using state-of-the-art chemical forensics and a bit of old-fashioned detective work, scientists confirmed that mysterious material found floating in the Gulf of Mexico came from the Deepwater Horizon rig. They further determined that tracking debris from damaged rigs can help forecast coastal impacts and guide response efforts in future spills.
NASA sees repeating La Niña hitting its peak
La Niña, "the diva of drought," is peaking, increasing the odds that the Pacific Northwest will have more stormy weather this winter and spring, while the southwestern and southern United States will be dry. Sea surface height data from NASA's Jason-1 and -2 satellites show that the milder repeat of last year's strong La Niña has recently intensified, as seen in the latest Jason-2 image of the Pacific Ocean.
Ice age findings forecast problems: Data from end of last Ice Age confirm effects of climate change on oceans
The first comprehensive study of changes in the oxygenation of oceans at the end of the last Ice Age has implications for the future of our oceans under global warming. The study looked at marine sediment and found that that the dissolved oxygen concentrations in large parts of the oceans changed dramatically during the relatively slow natural climate changes at the end of the last Ice Age.
Wandering albatross alters its foraging due to climate change
Wandering albatrosses have altered their foraging due to changes in wind fields in the southern hemisphere during the last decades. Since winds have increased in intensity and moved to the south, the flight speed of albatrosses increased and they spend less time foraging. As a consequence, breeding success has improved and birds have gained 1 kilogram.
Scientists look to microbes to unlock Earth's deep secrets
Of all the habitable parts of our planet, one ecosystem still remains largely unexplored and unknown to science: The igneous ocean crust. This rocky realm of hard volcanic lava exists beneath ocean sediments that lie at the bottom of much of the world's oceans. While scientists have estimated that microbes living in deep ocean sediments may represent as much as one-third of Earth's total biomass, the habitable portion of the rocky ocean crust may be 10 times as great.
World's most extreme deep-sea vents revealed: Deeper than any seen before, and teeming with new creatures
Scientists have revealed details of the world's most extreme deep-sea volcanic vents, five kilometers down in a rift in the Caribbean seafloor. The undersea hot springs, which lie 0.8 kilometers deeper than any seen before, may be hotter than 450 °C and are shooting a jet of mineral-laden water more than a kilometer into the ocean above.
Gulf of Mexico topography played key role in bacterial consumption of Deepwater Horizon spill
When scientists reported that bacterial blooms had consumed almost all the deepwater methane plumes after the 2010 Gulf of Mexico Deepwater Horizon oil spill, some were skeptical.
Bycatch-22: Protecting Butterfish
Scientists work to assist fishermen in ways to avoid accidentally hauling in butterfish, a species protected by fishing limits. The researchers develop models to predict where the fish will be.
Multi-year prediction of Atlantic Meridional Overturning Circulation at 26.5 °N possible
Climate scientists have now shown for the first time that the strength of the Atlantic Meridional Overturning Circulation at 26.5 °N can be skillfully predicted for up to four years.
New culprit in Earth's massive extinction: Mercury
Researchers have discovered a new culprit likely involved in Earth's greatest extinction event: an influx of mercury into the ecosystem.
Harp seals on thin ice after 32 years of warming
Warming in the North Atlantic over the last 32 years has significantly reduced winter sea ice cover in harp seal breeding grounds, resulting in sharply higher death rates among seal pups in recent years, according to a new study.
Russian river water unexpected culprit behind Arctic freshening, researchers find
A hemisphere-wide phenomenon -- and not just regional forces -- has caused record-breaking amounts of freshwater to accumulate in the Arctic's Beaufort Sea, researchers have found.
Russian runoff freshening Canadian Arctic, NASA finds
A new study allays concerns that melting Arctic sea ice could be increasing the amount of freshwater in the Arctic enough to have an impact on the global "ocean conveyor belt" that redistributes heat around our planet. Researchers detected a previously unknown redistribution of freshwater during the past decade from the Eurasian half of the Arctic Ocean to the Canadian half. Yet despite the redistribution, they found no change in the net amount of freshwater in the Arctic that might signal a change in the conveyor belt.
Flipped from head to toe: 100 years of continental drift theory
Exactly 100 years ago Alfred Wegener presented his theory of continental drift to the public for the first time. Modern plate tectonics confirmed his ideas by flipping them upside down.
'Lost world' discovered around Antarctic vents
Communities of species previously unknown to science have been discovered on the seafloor near Antarctica, clustered in the hot, dark environment surrounding hydrothermal vents. The discoveries include new species of yeti crab, starfish, barnacles, sea anemones, and potentially an octopus.
Debris scatters in the Pacific Ocean, possibly heading to US
Debris from the tsunami that devastated Japan in March could reach the United States as early as this winter, according to new predictions. However, they warn there is still a large amount of uncertainty over exactly what is still floating, where it's located, where it will go, and when it will arrive. Responders now have a challenging, if not impossible situation on their hands: How do you deal with debris that could now impact US shores, but is difficult to find?
Sea cucumbers: Dissolving coral reefs?
Coral reefs are extremely diverse ecosystems that support enormous biodiversity. But they are at risk. Carbon dioxide emissions are acidifying the ocean, threatening reefs and other marine organisms. New research analyzed the role of sea cucumbers in portions of the Great Barrier Reef and determined that their dietary process of dissolving calcium carbonate (CaCO3) from the surrounding reef accounts for about half of at the total nighttime dissolution for the reef.
Ocean acidification: Some organisms already experiencing ocean acidification levels not predicted to be reached until 2100
Ocean acidification research is a relatively new study topic as scientists have only appreciated the potential extent of acidification within the last decade. As greenhouse gas emissions have accelerated in the past century, the oceans have taken up about a third of the carbon dioxide produced by human activities. That excess beyond natural levels increases amounts of carbonic acid in seawater. New research shows that some organisms are already experiencing ocean acidification levels not predicted to be reached until 2100.
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