Little fish eat the phytoplankton, big fish eat the little fish, and so on. Since there are less phytoplankton, there will be less little fish, and less big fish. Convection and rainfall results from delivery of moisture and heat to the atmosphere there. El Ni o condition in the equatorial Pacific. The warm pool has lost water, which moves east, taking the convection center with it.
Trade winds are weak, and upwelling off Ecuador and Peru ceases.
This causes drought in Indonesia, storms in Tahiti, and ultimately the Peru Current is weakened and fishing is poor. When El Ni o occurs, the trade winds become weak and stop moving the warm water away from the coast. The warm water in the middle of the Pacific causes the winds to blow toward the warm pool. Clouds form over the new warm pool, fed by the moist winds collected from all around it, to the west and to the east. Heavy rains are the result, while New Guinea to the west is now rather dry.