Oregon Sea Grant

With El Nino taking the blame for everything from severe storms in California to an early spring in parts of the Midwest, maybe it's time to update an old saying: Everybody talks about El Nino, but nobody knows very much about it. This publication aims to help fill that knowledge gap by explaining in words and vivid images how the climate phenomenon works, and some of the ways it affects everything from the weather to fisheries productivity.

This publication is intended for a broad audience, including people who live and work on the Pacific coast, weather buffs and anyone interested in understanding the complex interplay between wind, current, and water temperature in the Pacific Ocean. It should be of special interest to members of the Pacific fishing industry trying to cope with dramatic changes in stock supplies and associated restrictions on what they are permitted to catch.

El Nino describes the waters off the Pacific Northwest as a region of transitions, where large ocean currents and atmospheric systems create "a remarkable and dynamic setting unlike any other in the world." Under normal circumstances, seasonal cycles of wind and atmospheric pressure help move relatively warm surface water away from the Pacific coast of North America. Cold, nutrient-rich water wells up from the deep sea to take its place, supporting a rich variety of fish life. The phenomenon known as El Nino, or the Southern Oscillation, disrupts those normal cycles, causing changes in weather that can be felt around the globe. The publication details some of those changes, and outlines what scientists know--and what they still do not know--about how El Nino may affect Pacific weather and fisheries.