Fishing grounds at current convergence
Topic: Movements of Ocean Water: Waves, Tides and Currents · NCERT: Class 11, Ch 13 "Movements of Ocean Water"
Meaning
Some of the world's richest fishing grounds lie where a warm current meets a cold current. The two waters mix. The mixing adds oxygen and brings nutrients up to the surface. This helps plankton (tiny drifting plants and animals) grow fast. Plankton are the main food of fish, so large numbers of fish gather there. The meeting of warm and cold water also produces fog, which makes shipping difficult.
Example
The Grand Banks off Newfoundland, Canada, form where the warm Gulf Stream meets the cold Labrador Current. Another example is the sea off Japan, near Hokkaido, where the warm Kuroshio meets the cold Oyashio.
Don't confuse with
- Upwelling zones: cold, nutrient-rich water rises from below along a coast, as off Peru. This happens because winds push surface water away from the shore. No second current has to meet it there.