In 1969 CalCOFI researchers took cores from an undisturbed accumulation of ocean-bottom sediments off Santa Barbara. Fish scales found within the sediments represented a 1,800-year record of pelagic fishes. Andrew Soutar, a Scripps specialist in paleontology, identified and counted sardine scales as an index of past sardine biomass. He found that the sardine population fluctuates through a cycle of decline and recovery about every 80 years. Only once previously, about 800 years ago, had there been such an abundance of sardines as was seen in the 1920s and 1930s.

CalCOFI researchers suspected that a combination of natural cycle, environmental change, and overfishing caused the sardine fisheries collapse.

CalCOFI has established the importance of long-term ocean monitoring in detecting and studying environmental change. “CalCOFI is a continuous record going further back in time than almost any other marine data set,” says Venrick. “Fifty years, by marine standards, is extremely long.”

Extensive data sets enable researchers to test the accuracy of prediction models and to define the normal range of conditions within the California Current. Once a baseline has been established, anomalies can be detected by viewing current oceanographic and biological conditions in the long-term context.

During the late 1970s researchers again observed dramatic changes in sea-surface temperature, ocean circulation, and climatology. The eastern Pacific became warmer, a phenomenon called a regime shift, impacting the climate and biodiversity along the California coast. “It’s the biggest documented change that’s taken place anywhere in the world’s ocean, and the reason [it has been documented] is because we have this wonderful time series,” says McGowan.

CalCOFI ocean monitoring was intensified during the 1997-1998 El Niño period, which was accurately predicted by Scripps researchers months in advance. This is one of the most informative studies conducted on the consequences of an El Niño to nutrient, chlorophyll, and zooplankton patterns, providing a close look at the links between ocean physics and biology. CalCOFI studies of the 1983-1984 and 1992-1993 El Niño events helped researchers predict how the ecology of the California Current would respond to this most recent El Niño.


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