NEKTON 



(«*) J (h M a E d N en 



RESIDENT RSH 



© /" > \/' X EXTERNAL 



*- WC—) STOCKS 



PRGRM^ V_^< "^ / 



\MIGRA-A/ "\ /^ N 



TION I ADULTS Y ^VE- 1 

 /PRGRMi I ADULTS I NILES J 



SCHOOLING RSH 



EXTERNAL 

 PREDATOR 



EXTERNAL STOCK 



Figure 5. Nekton ecosystem submodel presented in terms of state variables (shaded 

 symbols) and interactions (lines with arrows) among variables and with 

 external forcing functions (circles). Symbols are based on Odum (1971). 



143 



