1) The oceans are important sources of food, energy, minerals, and allow for transportation. They formed from water vapor in the atmosphere condensing over millions of years. 2) The oceans contain dissolved gases, salts, and other elements. Desalination plants remove salt from seawater to produce freshwater. 3) Ocean currents are large masses of water that circulate horizontally, powered by winds, and move different water temperatures in different directions around the globe.