-i»- 



computation is used to determine the current month's feeding computations. 



b) the computation is repeated with the component parameters adjusted to 

 reflect the current month's feeding and biomasses, as indicated below. 



c) step b is repeated until the biomasses values of successive iterations 

 converge. In practice it has been found that the values converge rapidly and 

 step b is computed once only. 



ZOOPLANKTON AND PHYTOPLANKTON 



The monthly biomasses of zooplanl<ton and phytoplankton are computed in the 

 same manner as those of the apex predators, namely, an input mean annual biomass 

 is adjusted by a cosine function to simulate seasonal variation. The period and 

 magnitude of this seasonal variation are controlled by input parameters. 



Components of the Biomass Equation 

 All components of the biomass equation are adjusted monthly by any or all of: 

 temperature, starvation and, following equilibrium, density dependent factors. 



GROWTH (GS,, , ^ 

 N,k; 



Species specific input values for growth {G^.) are adjusted in the following 

 equations. The last of these equations (density dependence) is only computed once 

 equilibrium has been reached. 



(J_ .L.) 



^ re - r ■■- o TA TM' 



Growth is adjusted by the difference between the current month's temperature, 

 TM, and the optimum, or acclimatization, temperature for the species, TA. Both 

 values are input parameters. The form of the equation follows Krueger (196'*)- 



^) ^^N,k = ^^N,k - ^''h -' 0-°' ' 'h,k^ 



