Answer:
The upwelling of seawater refers to the rising up of the deeper and cold water towards the surface of the sea. This cold water is comprised of the valuable and essential nutrients and as they move upward, it provides these nutrients to the marine organisms.
El Nino is usually defined as the large-scale changes in the climate that occurs due to the interaction between the ocean and the atmosphere. It leads to the episodic rise in the temperature of the sea surface, which typically occurs in the central and the eastern part of the central Equatorial Pacific.
The occurrence of El Nino leads to the reduction of the upwelling of deep-sea cold water. During the time of this harsh climate, the fishes die or they sometimes migrate into some other places where they can obtain their food. Due to this, the fisherman cannot go fishing.
Thus, the occurrence of El Nino directly affects a fisherman's life.