1. 1 History of Japanese fisheries MATSUDA Hiroyuki (Ocean Research Institute, University of Tokyo) 1. History of sardine fisheries & species replacement 2. History of whaling and tuna fisheries 3. History of fish and game

2. 2 Japanese are healthy-oriented people and use a wide range of marine bioresources.

3. 3 Longevity, calorie intake and de-pendence of grain in the diet (Source: Britannica International yearbook 1997)

4. 4 Total landings of pelagic marine fishes still increase. (redrawn from FAO 1994)

5. 5 Pelagic fish stock fluctuates

6. 6 Cyclic-advantage model of plankton-feeding pelagic fishes A model for May-Leonard Orbit N 1 ’=c 1 +N 1 exp[r 1 (t)-a 11 N 1 -a 12 N 2 -a 13 N 3 ] N 2 ’=c 2 +N 2 exp[r 2 (t)-a 21 N 1 -a 22 N 2 -a 23 N 3 ] N 3 ’=c 3 +N 3 exp[r 3 (t)-a 31 N 1 -a 32 N 2 -a 33 N 3 ] r j (t)=r j *[1+f j Z j (t)], Z j (t)=random var. (-0.5, 0.5) f j =amplitude of fluctuation (0 or 1)

7. 7 Cyclic-advantage conditions Co-existing equilibrium is locally unstable, and r j-1 /a j-1,j >r j /a j,j >r j+1 / a j+1,j (j=1,2,3) If sp.j reaches its carrying capacity r j /a jj, sp.j-1 increases but sp.j+1 does not. sp.1  3  2  1  3...

8. 8 Constant environment

9. 9 Fluctuating environment(f=1)

10. 10 Population management requires against uncertainties: Falsifiability (if sardine increases after anchovy, the cyclic- advantage model falls into error). Accountability (if previous premise is found to be wrong…) Adaptability (policy should be changed as the status changes...)

11. 11 Problems in Japanese fisheries 4.5 Mt of sardine was used to feed cultured fish, rather than foods for human. Demand of anchovy is low (maximum catch of anchovy was ca.0.4Mt in Japan, cf 12Mt in Peru) Few experience of management

12. 12 Population of hunters and game anglers

13. 13 Conclusion To eat more fishes and grains, Not to eat too much, To utilize a plankton-feeding pelagic fish that is temporally abundant To eat anchovy and pacific saury Not to catch a temporally rare fish