"You can post data the same day it's collected," said CalCOFI information manager Jim Wilkinson of Scripps Oceanography. "It used to take six months to work up some of the data and interpret it."
NOAA Southwest Fisheries oceanographer Frank Schwing said scientists' analytical tools provide better ways to assess the strength of anomalies such as warming that are associated with El Nio.
"We're taking a much more ecosystem-based approach to managing the system," said Schwing. "Because we are more on top of the observations, we can give a more timely heads-up to scientists and managers who are interested in the effects of El Nio."
The two research centers use data collected by satellites and buoy-mounted instruments to measure sea surface temperature. CalCOFI researchers embark on quarterly cruises off the California coast to collect vertical temperature profiles in the upper reaches of the water column. They also count eggs of commercially important fishes such as sardines and anchovies as well as measure plankton volumes to estimate the amount of "production" available to marine organisms. NOAA's Advanced Survey Technologies Group assesses fish populations through acoustic surveys. In contrast with the last major El Nio, Scripps now deploys Spray gliders, diving robots that now gather ocean temperature and other data along transects between CalCOFI stations.
The NOAA and CalCOFI scientists have observed a drop in biological abundance, or productivity, that appears to be related to the northward movement of warm water from the equator. The flow arrives in pulsing Kelvin waves that are detected by sea level and altimeter monitors and coastal tidal gauges. The layer of warm water often stifles the upwelling of nutrients from lower ocean depths that sustain larger populations of fishes and invertebrates.
The researchers reported finding fewer hake and anchovy eggs than usual in the most recent CalCOFI surv
|Contact: Robert Monroe|
University of California - San Diego