Long-term change and stability in the
Lessons from calanoid copepods off
Ginger Rebstock, Ph.D.
Scripps Institution of Oceanography
Wednesday, August 8, 2001
3:00 p.m.–Pacific Forum
The California Current System is generally considered to be highly
variable in both time and space. Physical variables and biological
populations are strongly influenced by interannual (e.g., El Niño) to
interdecadal (e.g., Pacific Decadal Oscillation) climatic fluctuations.
These low-frequency climatic variation have been accompanied by large
changes in biomass of zooplankton, planktivorous fish, and other
components of the ecosystem. Calanoid copepods undergo large,
species-specific fluctuations in abundance off Southern California, on
interannual to interdecadal scales. In spite of this variability, the
total abundance of calnaoid copepods shows no trend over the last 50
years. In addition, the dominance structure of large calanoid copepods has
remained stable. The California Current System, in spite of large
interannual variability and species-specific responses to environmental
changes, is a stable system at certain time scales and taxonomic levels.
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