Thursday 11 April 2013

Learn about Marine Life

By Alex Bruce


Technology brought the study of marine biology to new heights during the twentieth century. In 1934 William Beebe external (1877-1962) and Otis Barton external descended 923 m/3,028 ft below the surface off the coast of Bermuda in a bathysphere external designed and funded by Barton. This depth record was not broken until 1948 when Barton made a bathysphere dive to 1,372 m/4,500 ft. During the interim, Beebe was able to observe deep sea life in its own environment rather than in a specimen jar. Although he was criticized for failing to publish results in professional journals, his vivid descriptions of the bathysphere dives in the books he published inspired some of today's greatest oceanographers and marine biologists.

Some animals that have the word "fish" in their names are not really fish. Some examples are cuttlefish (they are mollusks, see below), jellyfish (they are actually plankton), and starfish (they belong to a group called "echinoderms"). Can you think of any other animals that are called fish but do not have the things it takes to be a real fish?

Sharks look a lot like marine mammals, but they are actually fish! Unlike most fish though, sharks do not have bones. Their skeletons are made up of cartilage instead of bones. Cartilage is the same stuff that makes your ears and the tip of your nose have their shape and be a little bit flexible. Even though they don't have bones, sharks do have lots of other similarities to bony fish. They are cold-blooded and breathe through gills instead of through lungs. Sharks have gills on each side of their heads. As they swim, water passes over the gills and oxygen flows in from the water.

Today, the possibilities for ocean exploration are nearly infinite. In addition to scuba diving, rebreathers, fast computers, remotely-operated vehicles (ROVs), deep sea submersibles, reinforced diving suits, and satellites, other technologies are also being developed. But interdisciplinary research is needed to continue building our understanding of the ocean, and what needs to be done to protect it. In spite of ongoing technological advances, it is estimated that only 5% of the oceans have been explored. Surprisingly, we know more about the moon than we do the ocean. This needs to change if we are to ensure the longevity of the life in the seas-and they cover 71% of the earth's surface. Unlike the moon, they are our backyard. Without a detailed collective understanding of the ramifications of pollution, overfishing, coastal development, as well as the long-term sustainability of ocean oxygen production and carbon dioxide and monoxide absorption, we face great risks to environmental and human health. We need this research so that we can act on potential problems-not react to them when it is already too late.

Not all sharks are large. Some only grow up to 7 inches long. However, most kinds of sharks grow to about 5-7 feet long, which is about the same height as an average adult. Not all sharks are dangerous to humans, either. There are over 350 kinds of sharks, but only about 25 of those have ever been known to attack humans. When sharks do attack people, it is probably because they mistake people for seals or other large ocean animals that they would like to eat. It is hard for them to tell what's what from below the surface of the water.




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