Answer:
"When El Niño occurs every three to seven years, a mass of warm Pacific water that is usually pushed westward by trade winds, surges back eastward toward South America".
Step-by-step explanation:
Under normal conditions, warm water and air masses move westward, which makes it possible for cold water to ascend in a process known as upwelling. This upwelling occurs in South America´s coasts, providing nutrients from the bottom to the animals, especially fishes -which favors fisheries activities-. Humidity goes straight to the west precipitating in Indochina and North Australia, among other places.
Under El Niño conditions, a tropical stream, that is normally small, acquires strength while the opposite streams debilitate. This avoids warm water to go westward, remaining in South America´s coasts, which produces unusual precipitations in Chile´s coasts -followed by floral bloom in Atacama desert-, and fewer precipitations in Eastsouth Asia and North Australia. Upwelling does not occur, so there is a fishery crisis because nutrients from the bottom do no ascend and fish populations remain equal or smaller.