Injormation Concept in Ecology 149 



been achieved. This enables the system to maintain or further 

 diminish its entropy. If the system possesses less free energy after 

 a passage of time, we say the balance is unfavorable and the system 

 is less able to forestall an entropy gain. These relationships can 

 be summarized by a simple transfer function which will be termed 

 cost. This variable represents the amount of energy which must 

 be expended to gain a unit of energy from the environment: 



P7r~ < 1 (biomass gain) 



[22] piv~^ = 1 (steady state) 



P7r~^ > 1 (biomass loss) 



where tt denotes total energy gained by the community and p 

 represents total energy lost. 



Let us now consider some specific behavioral and organiza- 

 tional attributes of planktonic systems which exemplify goal- 

 adaptability, the goal being biomass maximization. 



PROCEDURES 



The plankton communities under consideration occupied the 

 York River, Virginia, during the summer of 1960. For ten con- 

 secutive weeks, from June 23 to August 25, in situ dark and light 

 bottle differential oxygen studies (27) were performed weekly to 

 assess energy flux through the community. The sampling station 

 was located about 300 yds. off the end of the Virginia Institute of 

 Marine Science pier where the approximate depth of mean low 

 water was thirty feet. 



Hydrographic determinations included vertical profiles of chlor- 

 inity, temperature, dissolved oxygen, total dissolved phosphorus 

 and total nitrate. Temperature was recorded with a thermistor 

 unit. Chlorinity was titrated with silver nitrate. Dissolved oxygen 

 was measured by the unmodified Winkler method. Dissolved 

 organic and inorganic phosphorus were obtained as follows: 

 Fractionation into dissolved and adsorbed inorganic and dissolved 

 and particulate organic components was achieved by Millipore 

 (type HA) filtration. Inorganic fractions were assayed directly; 

 organic fractions were obtained by digesting samples for twelve 

 hours at 20 psi; the molybdate method (corrected for salt interfer- 

 ence) was employed to estimate the orthophosphate in both cases. 



