The most important fishing grounds of the world are found in the regio

The most important fishing grounds of the world are found in the regions where

warm and cold atmospheric currents meet
rivers drain out large amounts of freshwater into the sea
warm and cold oceanic currents meet
continental shelf is undulating
This question was previously asked in
UPSC IAS – 2013
The most important fishing grounds of the world are typically found where warm and cold oceanic currents meet. This is because the meeting of currents causes upwelling, bringing nutrient-rich cold water from the ocean depths to the surface. This nutrient supply supports a large growth of plankton, which forms the base of the marine food web, leading to high populations of fish and other marine life.
The convergence of different oceanic currents, especially warm and cold ones, is a major factor in creating productive marine environments suitable for large-scale fishing. Upwelling associated with these areas is key to nutrient availability.
Examples of major fishing grounds located at the convergence of currents include the Grand Banks off Newfoundland (meeting of the warm Gulf Stream and the cold Labrador Current) and the North Sea (meeting of the North Atlantic Drift and polar waters). The continental shelf is also important because it is shallow enough for sunlight penetration, supporting photosynthesis, but the current mixing provides the significant boost in productivity.