Contact: Susan Smith FOR IMMEDIATE RELEASE 6/17/97
According to NOAA, the U.S. West Coast is in the early stages of another El Nino episode that has been brewing in the tropical Pacific over the past several months. These periodic warming events usually emerge around Christmas time along the Pacific equator, and tend to occur every three to five years, typically showing up off California in winter or early spring. The last significant California El Nino occurred in 1992-93.
"The timing of this one is a little later than usual, more like the El Nino in 1982," commented oceanographer Ron Lynn, head of NOAA's El NinoWatch project at the Southwest Fisheries Science Center in La Jolla, Calif. "A typical El Nino wind and air pressure pattern appeared off the U.S. West Coast in May. If this persists, there should be strong warming of our coastal waters."
El Nino is a natural phenomenon, and marine ecosystems are adapted to deal with them, but NOAA scientists and National Marine Fisheries Service managers are still learning about their effects and how to best manage human activities as they may be affected by these naturally occurring changes.
"If it continues, we should see tropical and temperate marine species shift northward beyond their normal ranges, and other changes in marine life" said William Hogarth, acting regional administrator of the fisheries service's Southwest regional office in Long Beach, Calif. "We are particularly concerned about changes in the growth and production of some of our resident species."
Past El Ninos not only affected global weather patterns but also the large-scale distribution of marine life along the U.S. west coast. Fisheries service scientists expect favorable conditions for mahi-mahi and billfish, as well as certain small schooling fish that occur off California at the northern end of their range, such as mackerel and sardine. Officials note the appearance of yellowtail, albacore and bluefin tuna in Southern California waters in May could be an early effect of El Nino.
Californians may also see an increase in dead and live strandings of seals and sea lions along the coast, and poor seal and sea lion pup survival and growth at island breeding sites Fisheries service scientists suspect that El Nino conditions trigger a decline in the food supply of some marine predators. However, despite the likelihood of increased strandings of marine mammals, fisheries service scientists report the long-term trend of California sea lions and harbor seals shows a 6 to 10 percent annual growth rate. Periodic increases or decreases in the stranding rates of these animals do not reflect a danger to the health of the populations.
Resident bottom fish from Point Conception northward, such as the commercially valuable rockfish, may also be vulnerable because they are bound to local bottom topography.
"Any cold-water bottom fish is in for a tough reproductive season if this El Nino persists into the winter and spring of 1998. They do not go with the flow as do many of the pelagic fish," said John Hunter, chief of the coastal fisheries resources division at the La Jolla science center.
NOTE: Updates on tropical El Nino developments are available on the Internet through NOAA's Climate Prediction Center at http://nic.fb4.noaa.gov/products/analysis_monitoring/enso_advisory/index.html . El NinoWatch Advisories showing sea surface temperature effects along the U.S. West Coast are available through the service's Southwest Fisheries Science Center at http://cwatchwc.ucsd.edu/elnino/latest.gif.
