Physical Oceanography, Vol. 14, No. 6, 2004
OBJECT-ORIENTED MODEL OF FUNCTIONING OF THE PLANKTON
COMMUNITY OF THE SHELF
E. F. Vasechkina and V. D. Yarin
We propose to study the ecosystem of the plankton community of the euphotic shelf zone as a
complex system with five hierarchical levels. To construct the computer image of the ecosystem,
we use the methods of object-oriented modeling. The vital activity of the organisms of each spe-
cies inside a certain conventional volume of water (basic object of the model) is described in de-
tail. As a result, the entire system simulates the interaction of species in the analyzed ecosystem.
The system combines four groups of biological elements (phytoplankton, bacteria, protozoa, and
zooplankton) and biomineral elements (organic and mineral phosphorus) and includes the equa-
tions for the temperature of water and dissolved oxygen. The proposed numerical model repro-
duces the observed spotted character of the space and time distributions of the density of aquatic
life and its activity. The data of the performed numerical experiments reveal the correspondence
between the integral quantitative parameters computed in the model and the average characteris-
tics obtained under natural conditions.
At present, one of the principal problems of ecology is connected with the investigation of the nature of or-
ganization and maintenance of structural integrity of ecological systems and the analysis of the mechanisms of
control over the variety of species. Despite a great number of investigations carried out in the field of systems
ecology, the attempts of theoretical generalization encounter great difficulties connected with the diversity and
poor knowledge of the ecological and evolutionary processes as well as with the variability of external condi-
tions of existence of the analyzed systems. The investigation of the mechanisms responsible for the self-organiz-
ation of the ecosystem and its observed evolution proves to be an extremely important problem because, without
understanding the genetic relations, it is impossible to develop information technologies capable of giving reli-
An ecosystem is a complex system whose integral behavior cannot, in principle, be studied by splitting the
system into components and analyzing each of these components separately, since the aggregate dynamics of a
system of this sort is not determined by the sum of behaviors of its components. Therefore, in the process of in-
vestigation and subsequent simulation, it is necessary to analyze the ecosystem as a complex system. In contem-
porary investigations, a complex system is defined as a system of a large number of spatially distributed compo-
nents whose interaction can be essentially nonlinear. The dynamics of this system is characterized by the gener-
ation and development of multiscale structural features and dynamic patterns whose existence cannot be ex-
plained within the framework of traditional modeling. As a key feature of a complex system, one can mention
its hierarchical structure, i.e., each component of the system represents a collection of components of the lower
hierarchical level. There exist positive and negative feedbacks between the hierarchical levels specifying, to a
great extent, the observed complicated behavior of the system. As the principal features of the dynamics of
complex systems, one can mention their space and time self-organization, unpredictable appearance of abnormal
formations, adaptive behavior, and self-regeneration (for living systems). All these specific features are typical
of the observed behavior of actual ecosystems.
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol. Translated from Morskoi Gidrofizicheskii Zhurnal,
43–61, November–December, 2004. Original article submitted May 20, 2003.
360 0928-5105/04/1406–0360 © 2005 Springer Science+Business Media, Inc.