Case study of sardines and anchovies indicates that natural variability

in marine populations is real and large

in the absence of fishing

It took decades to realize the importance of different mechanisms

of change, such as decadal-scale variability

A combination of oceanographic surveys and paleo studies indicate that both population

size and distribution of fish and many other marine organisms vary tremendously,

perhaps coherently, in different regions of the world’s oceans

Previously unseen populations of anchovies suddenly appeared in sardine catches in the Gulf of

California in 1986

Holmgren and Baumgartner, 1993

Ecosystem Management(hard)

orEcosystem Awareness

(soft ecosystem management)

Climate Linkage Hypotheses(non-exclusive, non-exhaustive)

• Changes in basin-scale flow affect larval transport and survival (MacCall)

• Mesoscale eddies affect larval transport and survival (Smith)

• Energy flow through food web (productivity) determines larval recruitment (Chavez)

Hypotheses can be tested with sedimentary records

Hypotheses can be tested with sedimentary records

Santa Barbara Basin sediments

indicate large climate changes in past 60,000 years that all living marine

populations have experienced

But future changes may

differ from past changes

Fisheries lessons are selectively being applied to other regions

(Namibia, spiny lobster, striped bass)

Legal, economical and cultural changes are other important possibilities

• Invest in technology to preserve fish at sea

• Find better uses and recipes

• Change cultural views

Anchovy - cheap, nutritious The government subsidizes the soup kitchens, and the fish institute decided to use them to offer anchovy-based meals and to provide training in fish preparation (FAO).

10% efficiency

Sardines were once considered a tasty treat in California.It is time for another social and cultural regime shift!