Ancient explorers of the ocean were sailors and fishermen who learned about marine biology by observing the sea life and discovering when it was most plentiful. They observed the effects of wind, currents, and tides, and learned how to use them to their advantage, or to avoid them. These early humans discovered that salt could be retrieved from seaweed and grasses.
Polynesians combined what they knew about the weather, winds, and currents to investigate the Pacific Ocean, while the Phoenicians, Greeks, and Arabs explored the Mediterranean Sea. The early Greeks in general and Herodotus (484-428 B.C.) in particular believed that the world was round. Heroditus performed studies of the Mediterranean, which helped sailors of his time. He was able to take depth measurements of the sea floor by using the fathom as a unit of measure, which was the length of a man's outstretched arms. Today the fathom has been standardized to measure 6 ft (1.8 m) in length.
Aristotle (384-322 B.C.) also studied marine life. One of his contemporaries, a geographer by the name of Poseidarius, studied the tides and their relationship to the phases of the moon.
Pliny the Elder (A.D. 23-79) was a Roman naturalist who discovered, by studying marine biology, that some organisms had medicinal uses. One of his predecessors, Seneca (4 B.C.-A.D. 65)predicted that interest in the oceans would fade and "a huge land would be revealed." We know, of course, that this prediction came true with the discovery of North America. A period of about 1,000 years followed when no new studies were done until the fifteenth century. Christopher Columbus performed oceanographic studies on his voyages.
Captain James Cook, the explorer, was one of the first scientists to study the oceans' natural history. A surge in scientific studies took place in the seventeenth century, during which scientists tried for the fist time to combine the scientific method with sailors' knowledge.
U.S. Navy lieutenant Matthew Fontaine Maury (1806-1873) is considered the "father" of modern oceanography. It was during the nineteenth century that the name was given to the science.
In December 1872 the British ship HMS Challenger began a four-year journey, which lasted until May of 1876. This was the first major study done from a purely scientific viewpoint, and since that time significant strides have been made. The advent of submersible vehicles allowed for first-hand study of the ocean floor and the water above it. In 1900, Prince Albert of Monaco established two institutes to study oceanography.
Two areas of focus within oceanography today are physical and chemical oceanography. Physical oceanography is the study of ocean basin structures, water and sediment transportation, and the interplay between ocean water, air and sediments and how this relationship effects processes such as tides, upwellings, temperature, and salinity. Findings aid oceanic engineers, coastal planners, and military defense strategists. Current areas of research include oceanic circulation—especially ocean currents and their role in predicting weather-related events—and changes in sea level and climate.
Chemical oceanography investigates the chemical make-up of the oceans. Many studies in this area are geared to understanding how to use the oceans' resources to produce food for a growing population. In addition, the oceans may contain future sources of medicine, provide us with alternative energy, and help us to better protect our environment.
Even though the study of the oceans has entered the technological age, there is much we still do not know. Oceanographers of the 1990s use satellites to study changes in salt levels, temperature, currents, biological events, and transportation of sediments. As scientists develop new technologies, the future will open new doors to the study of oceanography.
See also Ocean.