It was anchovy fishermen in Peru who first noticed and named El Niño events in the tropical Pacific hundreds of years ago. Their catches would fluctuate and the largest declines were seen near Christmas when the ocean was at its warmest – they called it El Niño de Navidad, the boy of Christmas.
With a larger network of observations and some inspired statistical analysis, it became apparent that this decline in fish stocks was part of a Pacific-wide phenomenon including changes in the ocean and atmosphere. This was ENSO, the El Niño-Southern Oscillation.
