Long-term change and stability in the
 California Current System:
Lessons from calanoid copepods off
 Southern California

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.

Next: Temporal variations in phytoplankton community structure in the