Physical Oceanography, Vol.
MODELING OF THE DYNAMICS OF AGE STRUCTURE OF THE POPULATIONS
OF FREE-FLOATING COPEPODS IN THE BLACK SEA
E. F. Vasechkina
and V. D. Yarin
We study the dynamics of age structure of the populations of copepods with the help of a chemicobi-
ological model of shallow-water ecosystems developed on the basis of the technology of object-based
modeling of marine ecological systems. The role of a prototype of the model species of copepods is
played by Euterpina acutifrons (order Harpacticoida). The detailed analysis of parametrizations used
for the description of the life cycle of this species is presented. We analyze the results of numerical ex-
periments devoted to the investigation of a generation of copepods starting from the first stage of devel-
opment, formation of a stationary age structure under various temperature and trophic conditions, and
the appearance of population waves caused by the action of destabilizing factors on the population.
At present, the age structure of the populations of planktonic organisms is studied quite poorly, with the ex-
ception of several species of large copepods. At the same time, the knowledge of natural seasonal dynamics of
the age structure plays a significant role in the evaluation of the current state of a population and prediction of its
development. The investigation of the age structure according to the in-situ data encounters significant difficul-
ties due to the complexity of identification of species in the early stages of development of the organisms. This
observation is especially important for the nauplius stages, which are practically identical for different species.
In this connection, it is of interest to study the processes connected with the formation of the age structure within
the framework of the model approach in which it is possible not only to control external conditions of the devel-
opment of populations of hydrobionts but also to have complete information about the dynamics of the model.
In the present work, we simulate the dynamics of the age structure of populations of copepods with the help
of a chemicobiological model of shallow-water ecosystems developed within the framework of the technology
of object-based modeling of marine ecological systems. This approach naturally combines the marine ecology,
numerical modeling of the hydrophysical and hydrochemical processes and fields, and the object-based model-
ing of living components of the ecosystem . The model is described in detail in [1–3]. Hence, in what fol-
lows, we present only its brief description. The modification of the model used in the present work includes the
description of the life cycle of free-floating copepods, i.e., one of the most widespread and numerous taxonomic
groups of zooplankton, which enables us to study the dynamics of the age structure of populations of this type of
Description of the Model
The model contains three blocks conventionally called “hydrology,” “hydrochemistry,” and “biology.” The
hydrological block is represented by a two-layer integral model in which the upper layer bounded by the layer of
jump variable in time and identified with the layer of wind mixing. The upper layer gets the flows of momen-
Marine Hydrophysical Institute, Ukrainian National Academy of Sciences, Sevastopol, Ukraine.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
63–80, January–February, 2010. Original article submitted August 12,
58 0928–5105/10/2001–0058 © 2010 Springer Science+Business Media, Inc.