Sardine: a fable of six blind men and two elephants

Paul E. SmithNOAA-Fisheries Southwest Fisheries

ScienceCenter, La Jolla, California

CMD La Jolla November 2003

6 0 ° S

6 0 °

8 0 ° N

0 °

3 0 °

3 0 °

6 0 °1 2 0 °3 0 ° 3 0 °6 0 ° 9 0 ° 9 0 °1 2 0 ° 1 5 0 ° W 1 5 0 ° E1 8 0 °0 ° 3 0 °

Baja Sardine Eggs

0

10

20

30

40

50

60

70

80

90

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Temperature

n/1

0m2

The migratory sardine can be succinctly described as feeding in the north in summer, migrating south in autumn , spawning in the south in the spring and migrating north. Younger age groups may not migrate far.

The red arrow indicates the migratory range of a southerly stock of sardinesfrom another habitat with differing seasonalitymortality and growth rates.

Sardine Vertebral Count

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 200 400 600 800 1000 1200 1400 1600 1800

km ('south' of San Pedro)

Prop

ortio

n >

51

Pre Collapse

Post Collapse

1934 Sardine Catch

1000

10000

100000

1000000

1 2 3 4 5 6 7 8 9 10 11 12

Age

n

32

31

30

29 28

27

26 2524 23

22

British Columbia

Monterey

Summary

• We have demonstrated the ability to provide and instantaneous, absolute estimate of abundance of sardine and anchovy with individual and joint error estimates on all parameters.

• There is not enough money in the assessment system to provide these at the same time nor with sufficient frequency to regulate the fishery. Lower price proxy measures are used for regulation and appear to be sufficient for now.

Summary (cont)

• As to explaining biomass changes, or generating recruitment estimates, or relating the recruitment of sardine/anchovy, or the direct effect of the environment on either species, we continue to be immersed in a sea of ignorance.

• Despite this, the value of local time series and population dynamics and biological information on the CalCOFI anchovy/sardine pair is a beacon for interspecies interaction on the regional scale.