Ans: Several reasons contribute to the development of ocean currents. These are:Earth Rotation:Rotation of earth causes Coriolis force to emerge. This force deflects the currents and causes currents to move either clockwise or counterclockwise. Planetary Winds:Winds like westerlies, trade winds, etc., create surface currents and move them in particular directions. Other Reasons:Air pressure exerted on the oceanic waterThe difference in temperature in the equator area and polar regionsVaried salinity and varied densityPrecipitation helps salinity to reduce and get diluted, eventually leading to dilution of ocean water density and thus creates currents.