One telltale sign that this year's coming El Niño could be a big one is what’s been reeled in off San Diego's coast.

Above-average sea surface temperatures are developing in the tropical Pacific Ocean. The weather phenomenon, called El Niño, changes the heating pattern of the atmosphere and pulls the Pacific jet stream farther south. It has the potential to play havoc on weather systems across the globe, causing heavy rain and mudslides in some areas, drought in others, and disrupting the marine food chain.

Previous strong El Niños caused above-average rainfall and coastal erosion in San Diego. In 1997-1998, the event was credited with dumping 17 inches of rain at Lindbergh Field.

“This looks really a lot like the ’97-’98 El Niño event, which was one of the biggest ones ever recorded,” said Tim Barnett, marine research physicist emeritus with Scripps Institution of Oceanography.

“We’ll just have to wait and see how things develop in the summer,” he added.

Barnett said the ’97-’98 event caused a northward shift of the whole fishery population, drawing an abundance of albacore and Bluefin tuna to San Diego’s unusually warm waters.

“We’ve already started to see very unusual fish catches here,” Barnett said. “The first yellowfin tuna was caught in May — that has never happened before to anybody’s recollection.”

“And the other thing too is the first dorado Mahi Mahi — first of June," Barnett added, “that has never happened before. They really like the warm water and you normally don’t see them here until September.”

Barnett said both catches could be signatures of a coming large-scale El Niño. He said the tropical fish get caught up in currents caused by El Niño trade winds.

“They get entrapped in the current and they just swim along happily North,” Barnett said. “Unfortunately, it’s a one-way trip for most of them, it appears.”

In 1997-98, there were a lot of strange biological goings-on, Barnett added, like yellowtail being caught off Kodiak Island in Alaska. The tropical fish usually stops much farther south at Point Conception near Santa Barbara, California.

“And nobody could identify them, it’s really funny, they had never seen a yellowtail in Kodiak Island, and they had to send the fish out to be identified."



Barnett said it’s still too early to project this year’s El Niño strength, but the unusual fish sightings are a good early indication.

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