Oceanography The Official Magazine of
The Oceanography Society
Volume 16 Issue 03

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Volume 16, No. 3
Pages 76 - 85


CalCOFI in a Changing Ocean

Mark D. Ohman Elizabeth L. Venrick
First Paragraph

In 1999 the California Current changed. The ocean cooled, became somewhat less thermally stratified, and several characteristic species of zooplankton either decreased or increased in biomass. Many of these changes have persisted since that time (Figure 1). These ecosystem changes follow earlier shifts that occurred in 1976–77. Imagine the potential for misunderstanding the Northeast Pacific in the absence of such long-term observations. Any single year or limited group of years could yield a spurious picture of a dynamic ecosystem. Policy decisions and management guidelines would fail because they failed to take account of the underlying long-term variability.


Ohman, M.D., and E.L. Venrick. 2003. CalCOFI in a changing ocean. Oceanography 16(3):76–85, https://doi.org/10.5670/oceanog.2003.34.

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