By some measures 1997-1998 El Nino southern oscillation (ENSO) was the strongest such event of the 20 th century and perhaps the strongest of all recorded history. For most of us, an El Nino means increased rains in the Southern California area, due to a disruption of the normal path of the jet stream. In the study of marine ecology and fisheries biology, El Nino's have much more dire consequences. These winter storms can devastate our coastline and are accompanied by unusually warm and unproductive water. El Nino's have been cited as the cause of the collapse of fishery stocks as well as the demise of our world renowned kelp beds. ENSO events have increased in both frequency and magnitude for the past two decades, which has intensified our awareness of this global phenomenon. These changes, which we have seen in our coastal ecosystems, have implications of macroscale changes in oceanography extending far beyond the Southern California arena. As we sit on the precipice of the 21 st century, the staggering ramifications of these new oceanographic conditions trigger questions of global climate change and we are challenged with the prospects of global warming.