Question

Why are fishing ground located in areas where the the cold and warm current meet.p.?

Answer 1

this is because of the convergance of warm and cold currents. Because of the convergence, there is strong mixing of ocean waters. in such areas the nutrients so essential for marine organisms are in abundance. so, the marine life is rich in such areas. 

Answer 2

When a warm current and cold current meets , due to the warm nature of warm current , it rises over the cold current and the cold sinks.

Thus there is a struggle between the currents.

This results in the formation of fog due to the meeting of the warm and cold currents.

This formation of fog attracts planktons.

Planktons are food for fishes.

Hence fishes are attracted towards these areas.

This is the reason why the Oyashio current form the richest fishing grounds.