Fish in an unexpected spectrum of sizes, shapes and colors are moving north, through El Niño's warm currents from Mexican waters to the Pacific Ocean off California’s coast. El Nino is the periodic warming of the eastern and central Pacific Ocean. This phenomenon thrills scientists and gives anglers the chance of a once-in-a-lifetime big catch.
Thanks to El Niño, California's coastal waters have become more hospitable to fish from the tropics. Hammerhead sharks are among them.
“For over a year now, a lot of warm water fishes that we don't usually see have been coming up," said Rick Feeney, fish expert from the Natural History Museum of Los Angeles County.
The arrival of large numbers of big fish like wahoo and tuna has also invigorated California's saltwater sport fishing industry, which generates an estimated $1.8 billion a year.
"All the sport fish from Mexico are coming up here. In fact, there's probably more sport fish up here than there are down at the tip of Baja where they usually are. Things like marlin, yellowtail, wahoo, yellow fin tuna, blue fin tuna, all sorts of things that fishermen love to catch," said Feeney.
But southern California’s warmer waters are forcing out other species that local wildlife depend on.
"The normal stocks of anchovies and sardines have moved on. And a lot of the seal populations and sea lion populations, the pups are starving because the mothers can't find enough food. That might be one of the effects of El Niño," explained Feeney.
Researchers say the northern migration of fish in the Pacific Ocean has been one of the most dynamic effects of the climate phenomenon.
"Historically, it's a temporary change, and once El Niño stops, it just goes back to the cold water fauna. But we all know about global warming, and year by year we don't know how many of these fish will actually stick around and reproduce," said Fenney.
El Niño – and the tropical fish - are expected to be around until early next year.