the exception of large mobile macrozooplankton, in a single water sample 

 {Vinogradov et al . , 1976) 



3.1 

 Ecolog 



Methods of Calculation of the Secondary Production and 

 )gic-Physio1ogica1 Characteristics of Planktonic Animals 



The methods of determination of the production of aquatic animals 

 are outlined in a manuscript edited by G. G. Winberg (1968) and refined 

 and supplemented in later works (Zaika, 1972; Greze, 1973a, b; Bougis, 

 1974). 



Since we will be discussing basically the productivity of 

 zooplankton in tropical regions of the ocean, where the doubling time of 

 animals is long, it makes sense to discuss briefly the obstacles and 

 specific features of determination of the production rate in populations 

 which are constantly supplemented. In estimating the production of 

 populations of this type, the most precise values are yielded by the 

 graphic method used by G. G. Winberg and V. N. Greze, which is widely 

 used in production studies in sea and fresh water. To determine 

 production by this method, we must know the doubling rate of the 

 animals, the time of development of individual age stages and the age 

 composition of the population at known time intervals. Whereas it is 

 rather easy to produce this information for the populations of fresh 

 water, for marine areas, particularly open regions of the ocean with 

 complex hydrologic conditions and significant nonuniformity of the 

 distribution of plankton, both vertical and horizontal reliable material 

 on the age composition of the population is exceedingly difficult to 

 obtain, to say nothing of the difficulties involved in the study of the 

 times of development of animals in multispecies communities. Although 

 large numbers of publications have appeared in recent years, reporting 

 successful cultivation and study of the time of development of 

 individual species of zooplankton (Sazhina, 1968, 1974; Mullin, Brooks, 

 1970; and others), the question arises of the correctness of simple 

 transfer of data obtained in the laboratory to natural populations. 

 Therefore, as yet the use of the graphic method for determination of the 

 production of populations and communities in the pelagic zone of the 

 ocean is difficult although, for example, this method has been 

 successfully used for the Black Sea (Greze, Baldina, 1964; Greze et al . , 

 1968; 1971, 1973; G. N. Mironov, 1970, 1973; Petipa et al., 1970). 



The physiologic method is more applicable for estimation of the 

 rate of production in tropical planktonic communities (Winberg, 1964, 

 1968). To determine production by this method, we must know the number 

 of animals N, their weight W, the mean daily metabolic rate R and 

 coefficient of assimilated food used for growth Ko. Then, the mean 

 daily production of the population P can be calculated from the equation 



r-n^ 



NW (3.1) 



Calculation of the production by graphic and physiologic methods 

 yields similar results (Shushkina, 1972). 



288 



