California Sardines: A Fishery Biologist

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California Sardines A Fishery Biologists
History

• 1940s and 1950s Collapse of California
  sardine industry seen as management failure
• Development of the CalCOFI program
• Beginning awareness of climate effects (1957 El
  Niño)
• 1960s and early 1970s Rise of CC anchovy
  abundance suggests that ecology may be relevant!
• Competition becomes accepted explanation
• Overfishing of anchovy is proposed as a solution

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1970s (Surprises)

• Collapse of Peruvian anchoveta fishery
• Seen as parallel to CC sardine scenario
• Sudden increase in Japanese sardines
• Spontaneous, independent of management
• Soutar and Isaacs paleosedimentary scales show
  long-term variability is normal and large!
• Fisheries are absolved of responsibility

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The Paleosedimentary RecordSanta Barbara Basin

• There have been periods in the pre-fishery past
  when sardines were scarce
• Spectral analysis shows high energy in the 50-70
  year range
• (This figure is from a more recent analysis by
  Baumgartner et al. 1992)

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CalCOFI 1973 Birth of the Regime Concept

• there are probably a great number of possible
  regimes and abrupt discontinuities connecting
  them, flip-flops from one regime to another .
• Sardines, for example, are either here or not
  here.
• There are internal, interactive episodes locked
  into persistence, and one is entirely fooled if
  one takes one of these short intervals of a
  decade or so and decides there is some sort of
  simple probability associated with it organisms
  must respond to more than just fluctuations
  around some optimum condition . Fluctuations of
  populations must be related to these very large
  alternations of conditions.
  --John Isaacs (1976)

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Early 1980s (A Bigger Picture)

• Sardines are now abundant in Peru-Chile and Japan
  (Offshore!)
• Increasing in California
• Recognition that anchovy and sardine fluctuations
  appear to be synchronized on a worldwide scale

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FAO San José 1983

• Kawasakis sardine figure generated optimism
• Bakun and Parrish had described the main
  influences on abundance and distribution
• A breakthrough seemed imminent These events are
  so strong and clear, we should be able to
  discover the mechanism

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Late 1980s(Discovery Shift Happens!)

• Recognition of the mid-70s shift NE Pacific
• First discovered by Venrick et al. (1987)
• Trenberth (1990) later gained wide recognition
• The ocean is not stationary (time series)
• Fisheries focus moving to long-term variability
• Pauly and Tsukayama (1987) describe Peru as a
  complicated and dynamic system
• Major symposia held in Vigo and Sendai