About two-thirds of the world's population live within 500 km of a coastline. Therefore, the natural variations in the oceans have an impact on many people. In addition oceans, seas, lakes, ponds, rivers and streams that make up the hydrosphere contribute many things to society:

1. Nourishment

Many early people used the water in cooking, cleaning, and other aspects of living to help sustain their people. They also used the fish and seafood from the nearby bodies of water to feed themselves. This is also true today of people that live near large bodies of water.

Today many people dedicate their lives to harvesting the fish and seafood from the hydrosphere. Fishing vessels, sometimes traveling very far from their homes, gather fish and seafood to feed society. In Peru, the anchovy fishermen depend on the harvest of anchovies to provide for their families, however, the occurrence of El Niņo, a large warming of the waters in the tropical Pacific, has a large impact on the anchovy harvest. The normally cold waters in the eastern tropical Pacific Ocean contain many nutrients that feed the anchovies. When the warm waters from the western tropical Pacific Ocean move? to the east, these nutrients remain at deep levels in the ocean and are unavailable for the anchovies. As a result, the anchovies die or move elsewhere, destroying the annual harvest for the Peruvian fishermen. Thus, the Peruvian fishermen would benefit greatly if the phenomenon of El Niņo could be predicted, so that they can be better prepared to deal with the impact on their lives.

(Allen M. Shimada, NMFS/NOAA Corps) Large version

(Commander John Bortniak, NOAA Corps)
Large version

2. Transportation

Rivers and ocean currents were the original highways of mankind. Rivers permitted people to travel relatively quickly from one region to another and to move large quantities of goods from where they were obtained or made to the market place.

(USDA)

Once mankind could reliably sail across the Atlantic Ocean, the ocean currents provided a means by which trade could occur between continents. Today these trade routes across the ocean are still being used.

3. Power

Moving water can also be used for power. In historical times water wheels on small rivers and streams provided the power need to grind wheat and corn into meal for use in making food. Today large dams are built on rivers, and the release of the water produces large quantities of hydroelectric power used by many cities. In addition, the large lakes that form upstream of the dam provide large recreational areas.

Folsom Dam, California (U.S. DOI - Bureau of Reclamation)