Ocean currents have a number of direct and indirect effects on human activities.
- West coasts of the continents in tropical and subtropical latitudes (except close to the equator) are bordered by cool waters. Their average temperatures are relatively low with narrow diurnal and annual ranges.
- West coasts of the continents in the middle and higher latitudes are bordered by warm waters which cause a distinct marine climate. They are characterised by cool summers and relatively mild winters with a narrow annual range of temperatures.
- Warm currents flow parallel to the east coasts of the continents in tropical and subtropical latitudes. This results in warm and rainy climates. These areas lie in the western margins of the subtropical anti-cyclones.
- The mixing of warm and cold currents help to replenish the oxygen and favour the growth of planktons, the primary food for the fish population. The best fishing grounds of the world exist mainly in these mixing zones.