When two deep currents meet what happens

Grounds are located where warm and cold currents converge, where warm and cold currents meet happens to have regular foggy conditions, as the overlying warm and cold air come in contact with each other. They also tend to have high biological productivity, because plankton growth is encourage by the mixing of warm and cold currents. Some of the world's most productive fishing.

answer: blah

explanation:

bc blah