recruitment. The formula first used in Model III for the

density dependent function (normally expressed in energy

circiut language) was:


 = k FAS kl F2AS (1)



This function produced instability in the model because of

the seasonally oscillating sunlight and water area. Two

variables, therefore, were dropped from the second term and

the formula became:



 = kI FAS b F2 (2)


 Fish respiration (rate equation 2 in Figure 13).

Respiration per unit of fish biomass in a seasonally

expanding fish population decreases with density at the

lower densities and increases with density -at higher

densities. The fish respiration rate equation and its

coefficients used in the model were similar to the

quadratic equation (equation 27 in Results section). The

respiration formula was:



 = F(a2 b2F/A + c2(F/A)2) (3)


 Temperature effect on fish respiration (equation 15 in

Figure 13). Respiration of all organisms is affected by

temperature. The smaller the organism, the greater the