PACIFIC COAST OCEANOGRAPHY AND
FISHERIES-APRIL 98--Excerpts from the NOAA/NESDIS El Nino Watch Advisory
98-4 for April 1998:
"El Nino conditions in the eastern
tropical Pacific remained strong in April with positive sea surface temperatures
anomalies greater than 5.4 degrees F east of 90 degrees W longitude and
greater than 3.6 degrees F east of 130 degrees W. A negative subsurface
temperature anomaly indicative of mature warm episode conditions continues
to expand from the western Pacific into eastern Pacific waters as far as
120 degrees W. Modelers predict that equatorial conditions will return
to normal by June-July. Sea surface temperature anomalies along the US
west coast were about 1 degree F less than those observed in March, though
they still continue to be about 2-3 degrees F above normal. A core of cooler
than normal water persists 350 miles offshore central California.
Research cruises in April (NMFS and SIO) found that while surface temperatures were near or slightly above normal in coastal waters of southern and central California, subsurface temperatures at a depth of 300 ft were 4.5 degrees F above normal in coastal waters and as much as 9 degrees F warmer than normal beyond 100 miles offshore. Zooplankton volumes were low for this time of year but heavy spawning of sardine was observed north of Point Conception to San Francisco, and a high incidence of jack mackerel spawning in offshore waters. Upwelling indices in April were near normal along the US west coast, though upwelling was slightly below normal in Southern California. Salmon fishermen along the Pacific coast have reported below normal-sized fish showing up in the salmon runs. Seals and sea lions appear to be extremely stressed, with very low pup survival observed in breeding colonies [California]. Occurrence of larval rockfish off central California in surveyed areas was found to be very low, indicating poor recruitment." VIA Susan.smith@noaa.gov.