FISHERY BULLETIN: VOL. 70. NO. 2 



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Appendix Figure 1. — A phase diagram of optimal 

 solution paths. 



|k ^ p + 1 _ [1 _ /(A;,)] dRJdSu [A-14] 



rfi? 



S5t/9St - ^1 -/(fct)] - 1. 



[A-15] 



Using [A-8], [A-9], [A-14], and [A-15], and 

 assuming that [1 — f{kt)'\ j^ ^ 1, 



/ = 



9Xt axt 

 g-St dSt 



< 0. 



If r is substituted for p in the determinant, it 

 equivalent to the one discussed in the second 

 section. 



As in the second section, it is not possible to 

 prove that the equilibrium solution satisfies suf- 

 ficient conditions for a maximum, since, in this 

 case, it is not possible either to prove or disprove 

 the concavity of the Hamiltonian. 



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